fatigue data book - light structural alloys

Fatigue Data Book: Light Structural Alloys

Scott D. Henry, Manager of Reference Development Grace M. Davidson, Manager Reference Book Production

Sbven R. Lampman, Technical Editor Faith Rsldenbach, Chief Copy Editor

Randall L. Boring, Production Coordinator William W. Scott, Jr., Director of Technical Publications

Editorial Assistance Kathleen S. Dragolich

Nikki 0. OiMatteo

Copyright 0 1995 by

ASM International@ All rights reserved

No part of this book may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the written permission of the copyright owner.

First printing, November 1995 Digital printing, September 201 1

This book is a collective effort involving hundreds of technical specialists. It brings together a wealth of information from worldwide sources to help scientists, engineers, and technicians solve current and long-range problems.

Great care is taken in the compilation and production of this book, but it should be made clear that NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING, WITHOUT LIMITATION, WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, ARE GIVEN IN CONNECTION WITH THIS PUBLICATION. Although this information is believed to be accurate by ASM, ASM cannot guarantee that favorable results will be obtained from the use of this publication alone. This publication is intended for use by persons having technical skill, at their sole discretion and risk. Since the conditions of product or material use are outside of ASM's control, ASM assumes no liability or obligation in connection with any use of this information. No claim of any kind, whether as to products or information in this publication, and whether or not based on negligence, shall be greater in amount than the purchase price of this product or publication in respect of which damages are claimed. THE REMEDY HEREBY PROVIDED SHALL BE THE EXCLUSIVE AND SOLE REMEDY OF BUYER, AND IN NO EVENT SHALL EITHER PARTY BE LIABLE FOR SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES WHETHER OR NOT CAUSED BY OR RESULTING FROM THE NEGLIGENCE OF SUCH PARTY. As with any material, evaluation of the material under end-use conditions prior to specification is essential. Therefore, specific testing under actual conditions is recommended.

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Library of Congress Cataloging-in-Publication Data

Fatigue data book: light structural alloys. p. cm.-Includes bibliographical references.

1. Light metal alloys-Fatigue. I. ASM International

TA484.F37 1995 620.1'66dc20 95-39481

ISBN-13: 978-0-87170-507-5 ISBN-10: 0-87170-507-9

S A N : 204-7586

ASM International@ Materials Park, OH 44073-0002

www.asminternational.org

Printed in the United States of America

Table of Contents IovF- . . . . . . . . . . . . . . . . . . . 1

AluminumAlloyS-NFatigue, ...................... 3 Effect of Environment ..... , , . . , . , ................ I ... , . 3 Effect of Microporosity . . . . . . , . , . . . . , ............. , . . . . . 7

AluminumAlloyS.NData ......................... 13 Alumlourn and 2xm Alloys I ...................... , . , . , 13

UnalloyedAluminum . . . . . . . . . . . . , ..... , .. , .... , . , . , 13 2008 ................., ........................ .. 13 2011 ................. ...,............., . I . I , . , , , 14 2014 ........... I .. , .. , , ............ , . . , , . . , . . , . , 15 2017 .. .......,.. ............. , ..... , ...... 3 I . I .. 17 2024-T3 . # ... I .......................... I . . , .., .. 18 2 W T 4 ........ I ....................... I .... I ... 19 2CQ4T6, . . . . . . . I ................. , ,., I . I ........ 22 m T 3 6 . . T351 and.T361 .............. , . . , .... , ... 22 2024-T86..T851..TS52..T861 . .... , . , . , , . ... I ... 23 2025 .. , , . . , . I ................................... 26 2124 ................................ , . . , . . , . . . . . 26 2219-T6and-T8 . . . . . . . . . I ......... ..., ..,.., ..... 27 2219-T62 .... I ....................... ............ 28 2219.T87 ............. . . , . . . . . . , . . . . , , . . , . . , . . I .. 28 2219-TS51 ..................... I ................. 31 2618-T6d-T651 .............. I . I . . . ..... .. 33

3003 .... I ........ I .. I * . I ............ I . . . . . a . . . . . 34 3004., , ....... , . . , .................... , . . , . . , ... 29

4xxxandSxxxAUoys ........................... , ..... 37

4043 .... ....,..,.... ...,.,....,..... , . . , . . , . . , . , 38 5005 , ... . . . . . . . . . . . . . . . . . . . , , . . . . . , . , 38 5050 ................................ . . . I . . I . , I . , 39 5052 .........., I I ........... , ..... , .. , .. , . . . . q 39 5053 ...........,., .................... , , . . . . , . . . 41 5056 ... . . . . . . . . . . . . , . , . . , ............. . . . . . . , . , . 42 5082 . . . . . . I . . I . . . . . . , ... 43 5O83-0~1d.HIl . . . . . . . . . . . . . . . . . . . , , . . I I . . . I . . . . , . 44 5083.H112 . . . . . . . . , . . . I .......... * , . . . . I . . I . . . . I . 45 5083.H31..H32.m d.H34 ................ I . . . , . .... 49 5083-H113 . . . . . .................................. 50 5083.H321. .H323 .. I ............................ , . 54 5086 ............................................ 55 5154 ...................................... 1 ..... 59

5356 . . . , .................................. , ..... 60 5454 ............................................ 61 5456 ................. I I . I ..................... 64 Alloy Name: 5456 ................................. 67

QxxxAUoys , ........................................ 70 6009 .......................................... , . 70 6010and6013sheet . . . . . . . . . . . ..................... 70

6061 ................................... . . . . . . . . , 71

3xxx and 4xxx Alloys ..................... I ........... 34

4032.T6 ................................ , .. , .... 3 37

e .. e . . . . I .

5182-0Shet ..................................... 60

5456-H343 ....................................... 69

6053.T6 ....................................... , . 71

Alloy Name: 6061 ................................. 76 6063 ............................................ 78

7xlaAlboys ......................................... 79 7002 ............................................ 79 7005 ............................................ 79 7039 ............................................ 80 7049 ............................................ 81 7050 ............................................ 81 7075-0 and -T6 .................................... 90 7075-73 ........................................ 95 7075-T6510.-T7351.and-T73510 .................... 96 7075 Corrosion Fatigue ............................ 101 7076.7079.and7106 .............................. 102 7079andX7080 .................................. 103 7149-73 ....................................... 104 7175 ........................................... 105 7178 ........................................... 106 7475 ........................................... 110

. . . . . . . . . . . . . . . . 115 MagnasiumAUoyeFatigueandFrsctum .......... 117

Physical Metallurgy .................................. 118 castinp ........................................... 119

Zirconium-Freecasting Alloys ...................... 120 Zirconium-Containing Casting AUoys ................. 120 Production of Castings ............................. 123 MechanicalRoperties ............................. 123

Wrought Alloys ..................................... 124 Wrought Forms ................................... 130 Wrought Mechanical Properties ...................... 131

Novel Magnesium Alloys ............................. 138 FatigueStrength. .................................... 139 FrsctureToughnessandCrackGrowth ................... 141 StressComionandComsionFatigue .................. 144

Stms-Comaion Cracking .......................... 144 Corrosion Fatigue ................................. 146

MagnesiumAUoyFatigueData.. ................. 161 Mg-AlCastingAlloys ................................ 151

AMlOOA ....................................... 151 AZ63A(UNSM11630) ............................ 151 AZ63A. Notched Fatigue ........................... 152 AZ91B (UNS M11912)AxialFatigue ................. 152 AZ91B. Rotating- ............................ 152 AZ9 1 B. Plate Bending ............................. 153 AZ91C (UNS M1194). UnnotchedFatigue ............. 153 AZ91C.NotchedFatigue. .......................... 153 AZ9 1C. Strain-Life Fatigue ......................... 154 AZ91D-HP(UNSM11916).Strain.LifeFatigue ......... 154 AZ91E&l”S M11919). Strain-LifeFatigue ............ 154 AZ91EFatigueCrackGrowth ....................... 155 AZ91E. Corrosion Fatigue .......................... 155 AZ91E.CrackGrowth withCorrosion ................. 155 AZ92A(UNS MI 1920). UnnotchedFatigue . . . . . . . . . . . . 156

V

AZ92A. Notched Fatigue. .......................... 156 Mg-A1 Wrought Alloys .............................. I57

AZ31B (UNS M11311) ............................ 157 AZ31B. Plate Bending Fatigue ...................... 157 AZ3 1 B. Sheet. Bending Fatigue ..................... 157 AZ31B. Strain Life Fatigue ......................... 158 AZ3 1 B. Corrosion Fatigue .......................... 158 AZ3 1 B. Fatigue Crack Growth ...................... 159 AZ261A(UNSM11610) ........................... 159 AZ61A. Extmsion ................................ 159 AZ61ABar ...................................... 160 AZ61A.Plat.e .................................... 160 AZ8OA(UNSM11800) ............................ 160 AZBOA (E T4. TS, and T6 Tempers) . . . . . . . . . . . . . . . . . . 16 1 AZSOA-TS. Notched . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 1 AZ80A. Bending Fatigue. .......................... 162 A Z S O . Axial Fatigue ............................... 162 AZ8lA(UNSM11810). ........................... 162

Mg-ZnAUoys ...................................... 163 ZEAlACasting Alloy (UNS M16410) ................. 163 ZK61ACastingAlloy (UNS M1660) . . . . . . . . . . . . . . . . . 163 ZH 62ACasting Alloy (UNS M16620) . . . . . . . . . . . . . . . . 164 ZElOASheet (UNS M16100) ....................... 164 X 6 0 A Exnsions ................................ 165 ZK60A (UNS M166W) Fatigue Strength . . . . . . . . . . . . . . 166 ZK60AFatigue Strength ........................... 166

ZK60A Extrusion. Fatigue Crack Growth in Water . . . . . . . 168 Mg-Th Alloys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170

HK31A(UNS M13310) ........................... 170

HM21A(UNS M13210) ........................... 171 HM21A.AirandVacuumFatigue .................... 171 HM21ASheet ................................... 172 HM31A(UNS M13312) ........................... 172

Mhceilaneous Mg Alloys ............................. 173

Room Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 QH21 (UNS 18210) .............................. 173 QE22A. High-Temperature S-N Data . . . . . . . . . . . . . . . . . QE22AFatigue Crack Growth ...................... 174

EZ33A. High-Temperature Fatigue . . . . . . . . . . . . . . . . . . . 175 EZ33AFatigueCrackGrowth ....................... 176

LA141ASheet ................................... 176 MIA(UNS M15100) ............................. 177 MlAFatigueCrackGrowth ........................ 177 GA3Zl StrainLife. ............................... 178 Russian Alloys: Fatiguecrack Growth . . . . . . . . . . . . . . . . 178

ZK60A(UNS M16600)Plate. FatigueCrackGrowth . . . . 167

HZ32A(UNSM13320) ............................ 171

Magnesium-Silver Alloys: Fatigue Strength at

I74

Magnesium-Rm Earth Casting Alloy EZ33A (UNS M 1 2 3 3 m

Magnesium-Lithium Wrought Alloy LA 141A(UNS M14141E6

llov F w Dam . . . . . . . . . . . . . . . . . . 181 Titanium Alloys Fatigue and Fracture . . . . . . . . . . . . 183

Metallurgy of PEtanium Alloys ......................... 183 Metallurgy of Ti-6Al-4V ........................... 183 Other Alpha-beta and Alpha Alloys. . . . . . . . . . . . . . . . . . . 187 Metallurgy of Beta Alloys .......................... 188

FractureToughness ............................... 189 Fatigue Crack Propagation. ......................... 192 Sustained-Load Crack Propagation . . . . . . . . . . . . . . . . . . . 197

Mechanical Properties: Beta Alloys ...................... 198

Mechanical Properties: Alpha and Alpha-Beta Alloys . . . . . . . . 189

Commemially Pure and Modifled Titanium . . . . . . . 205 Unalloyed Ti Grade I. R50250. ......................... 205

Chemistry ....................................... 205 Product Forms and Condition ........................ 205 Applications ..................................... 205

Unalloyed Ti Grade 2. R50400 ......................... Un Chemistry. ...................................... 207 product Forms and Condition ........................ 207 Applications. .................................... 207

Unalloyed Ti Grade 3. R50550 ......................... 209 Chemistry., ..................................... 209 Product Forms and Condition ........................ 209 Applications. .................................... 209

Unalloyed Ti Grade 4. R507OO ......................... 211 Chemistry ....................................... 211 Product FormsandCondition. ....................... 211 Applications ..................................... 211

Ti-0.2Pd, R52400 (Grade7) . R52250 (Grade 11) . . . . . . . . . . . 212 Chemistry., ..................................... 212 Product Forms and Condition ........................ 212 Applications ..................................... 212

Ti-0.3M0-0.8Ni.RS3400 .............................. 214 Chemistry ....................................... 214 Product Forms and Condition ........................ 214 Applications ..................................... 214

Fatigue Roperties ................................... 215 Fracture Roperties., ................................. 216

Fracture Mechanism Maps. ......................... 217 TiSAI=2.W ..................................... 218

Chedstry and Density. ............................ 218 Product Forms ................................... 218 Product Conditionm'iimstructure .................... 218 Applications ..................................... 218

Fatiguebperties ................................... 219 FractureProperties ................................... 221

ImpactToughncss ................................. 221 FractureToughness .................................. 221 Seamless Tubing .................................... 222

Typical Roperties ................................. 222 TidAl.2.6Sn .................................... 223

ChemistryandDmsity ............................. 223 ProductForms ................................... 223 Product ConditionlMicrostmcturere .................... 224 Applications ..................................... 224

FatigueLife ........................................ 225

FatigueCrackGrowth ................................ 227 Fractunhperties., ................................. 228

Low Temperatu re. Toughness (Standard and ELI) ........ 229 ELI Fracture Toughness ............................... 231

'L'~=~A~=~S~=~Z~-~MO.O.OSS~ ....................... 232 Chemistry and Density. ............................ 232 Product Forms ................................... 232 Product ConditionlMicrosmcture .................... 232 Applications. .................................... 232

Phases and Suuctures ................................. 233 Fatigue Roperties ................................... 233

Duplex Annealed Sheet ............................ 233 Duplex Annealed Bar. ............................. 234 Duplex Annealed Forgings. ......................... 235

Fracturehperties ................................... 236 Impact Toughness. ................................ 236

Low-Temperature Fatigue Data ...................... 227

vi

Fracture Toughness ............................... 237

Chemistry and Density ............................. 238 ProductFom ................................... 238 Product Condition/Microstructure .................... 238 Applications ..................................... 238

Fatigue Properties ................................... 239 Unnotched Fatigue Life ............................ 239 Notched Fatigue Life .............................. 240 Implant Material Fatigue ........................... 242

FatigueCrack Growth ................................ 242 Forged Fan Blades ................................ 242 Environmental Effects ............................. 243 Effect of Frequency ............................... 244

Fracturehperties ................................... 244

TI-8AI-lMO-lV .................................. 238

Impact Toughness ................................. 244 Fracture Properties. ............................... 245

TrMmAT? 1100 ................................ 246 Physical Properties .................................. 247 Mechanical Propities ................................ 248

Fracturehperties ................................ 249 Processing ......................................... 249

Fatigue Properties ................................ 249

Forging ......................................... 249 IMI 854 Ti-6.8A14SnSbZr-0.7~,6M~.36Si . . . . . 260

Physical Properties .................................. 250 Mechanical Properties ................................ 25 1 High-Temperature Strength ............................ 251 Fatigue Properties ................................... 252

Crack Propagation ................................ 253 Processing ......................................... 254

Casting ......................................... 254 Forging ......................................... 254 Forming ........................................ 254 Heat Treatment ................................... 255

TibAI.2Sn.2Zr-4Mo-4Cr .......................... 255 Product Conditionsl Microstructure . . . . . . . . . . . . . . . . . . . 255 Chemistry and Density ............................. 255 Product Forms ................................... 255 Product Conditions/ Microstructure . . . . . . . . . . . . . . . . . . . 255 Applications. .................................... 255

Fatigue Properties ................................... 256 Fatigue Crack Growth ............................. 257

FractureProperties ................................... 258 Forging ........................................... 259

Ti.6Al-2Sa.4Zr6Mo .............................. 260 Chemistry and Density ............................. 260 ProductForms ................................... 260 Product Condition/ Microstructure . . . . . . . . . . . . . . . . . . . 260 Applications. .................................... 260

Phases and Structures ................................ 261 TransformationProducts ........................... 261

Fatigue Properties ................................... 261 HighCycle Fatigue ............................... 261 LowCycle Fatigue ................................ 262 Fatigue Crack Growth ............................. 262

FractUreProperties ................................... 263 Fracture Toughness ............................... 263

TisA14v ....................................... 264 Introduction., ...................................... 264

LowCycle Fatigue ................................ 252 High-Cycle Fatigue ............................... 253

Chemistry ....................................... 264 ProductForms ................................... 264 Product Condition/ Microstructure .................... 265 Applications ..................................... 265

Phases and Structures ................................. 268 Transformation Structures .......................... 270 Ti3Al Precipitation ................................ 270

General Fatigue Behavior ............................. 271 Low-Cycle Fatigue .................................. 272

StrainLife ....................................... 273 Stress-Controlled LCF ............................. 273 CastandPiM .................................... 273

Fatigue Limits and Endurance Ratios .................... 275 Endurance Ratio .................................. 276 Variation of Endurance Ratio ........................ 276

Surface and Texture Effects on Fatigue . . . . . . . . . . . . . . . . . . . 277 Effect of Residual Stress ............................ 277 Effect ofTexture .................................. 277 Effect of Surface Treatment ......................... 278

Influence of Mean Stress .............................. 280

Effect of Thennomechanical Processing ............... 281 Effect of Heat Treatment on Fatigue ..................... 282

Fretting Fatigue .................................. 279

Effect of Processing. ................................. 281

Annealing ....................................... 282 Effect of Cooling ................................. 283 STACondition ................................... 283

Constant-Life Fatigue Diagrams ........................ 284 Duplex Annealed Sheet ............................ 286 Beta Annealed Plate ............................... 287 At315"C ....................................... 288

Unnotched Fatigue Strength ........................... 290 Plate ........................................... 290 Sheet ........................................... 292

StrainLife ......................................... 294 Notched Fatigue Strength ............................. 295

Plate ........................................... 297 Bar and Extrusions ................................ 298 Sheet ........................................... 299

Cast and P/M Fatigue ................................. 301 PA4 ............................................ 303

Corrosion Fatigue ................................... 304 Compared to Stainless Steel ......................... 306

Fatigue Crack Growth in Air ........................... 307 Effect of a-p Processing ........................ I . . . . 308 FCP Resistance of Transformed p .................... 309

Crack Growth and Corrosion ........................... 310 Aqueous Halide Solutions .......................... 311 Effect of Test Frequency ............................ 312

Impact Toughness ................................... 313 Fracture Toughness .................................. 316

Effects of Processing .............................. 317 Weldments ...................................... 320 Effect ofTemperature .............................. 322 Hydrogen Embrittlement ........................... 323

Ti-BAl-BV-2Sn ................................... 327 Chemistry and Density. ............................ 327 Product Forms ................................... 327 Product ConditionslMicrostructure . . . . . . . . . . . . . . . . . . . 327 Applications ..................................... 327

Phases and Structures ................................. 328 Crystal Structure .................................. 329

vii

'IfansformationProducts., ......................... 329 Low-CycleFatigue .................................. 330 High-Cycle Fatigue .................................. 330 ConstmtLifcheDiagtams ........................... 332 Fatigue Crack maga t ion ............................ 334 Fra~tureRoperties., ................................. 336 Impart Toughness ................................. 336 FcactureToughness ............................... 336

Ti-6442.22S TiSA19Sn=2Zr-ZM~2C~O.~Si . . . . . . . . . . . . . . . . . . . 338

PhysicalPmperties .................................. 339 WasesandSauctures .............................. 339 ElasticRoperties ................................. 339 Cornsion ....................................... 340

TensileProperties ................................... 340

Sheet ............................................ 341 High-Temperature Strength ............................ 342 High-Twnperature Saength ............................ 343

CreepStrengWCreepRupture ....................... 343 High- and LowCycle Fatigue .......................... 345

DAForged Billet ................................. 345 STAPlatc ....................................... 346 Beta-Rocessed Material ........................... 346

Fatiguecrack Propagation ............................ 347 Billet ........................................... 347 STAPiate ....................................... 347 Beta-RocessedCondition .......................... 348 3.5%baCl ...................................... 349

Fracture Roperties .................................. 350 Plastickfomtion .................................. 351

Seain Hardening ................................. 35 1 Flow Stress ...................................... 351

T ~ S A ~ - ~ V - B C I ~ M O ~ Z ~ { B ~ ~ ~ C ) . . . . . . . . . . . . . . . . . . . 351 Chemistry and Density ............................. 352 Product ConditiodMicrostructure .................... 352 Applications., ................................... 352

Phases and Structures ................................ 352 FatigueProperties ................................... 353

Fatigue Crack Growth ............................. 354 FracNreRoperties ................................... 355

Ti-1OV-2FEt.W .................................. 356 ChemislryandDensity., ........................... 356 M u c t Fonns ................................... 356

PlateandForgings ................................ 340

Product ConditionlMimstructure .................... 356 Applications ..................................... 356

Fatigue(Smth) .................................... 357 Low-CycleFatigue ................................ 358

HighCycle Notched Fatigue. .......................... 362 Room Temperature. ............................... 362 Elevated Temperature. ............................. 362

HighCycleFatigue: PIM and Cast ...................... 363

FractureToughness .................................. 366 Effect of Microstructure and Processing ................ 367 Effect of Processing ............................... 369

Ti-lSVSCr-3Ai-SISn .............................. 370 Chemistry and Density ............................. 370 Product Forms ................................... 370 Product CondifiondMicrostmctuure . . . . . . . . . . . . . . . . . . . 370 Applications. .................................... 370

Fatiguebperties ................................... 371 Fatigue Crack Gmwth ............................. 371

FractureProperties., ................................. 372

Physical Properties ................................... 374

ThennalRoperties ................................... 376 Heat Capacity. ................................... 376 ThennalExpansion ................................ 376 ThmlConductivity., ............................ 376

Tensile Properties .................................... 377 High-TemperatureStrength ............................ 379 CrackResistance .................................... 380 Processing ......................................... 381

Forging., ....................................... 381

Fatigue Criick Growth ................................ 364

Q TIMETAL 218 .................................. 373

Corrosionhperties ................................. 375

Ti=6Al-2Sn-4Zr4Mom2ClclFe Beta.CEZ@ ..................................... 382

Physical Properties ................................... 382 Mechanical hperties ................................ 383 Tensile Properties ................................. 383 Fatigue ......................................... 384 Crack Propagation Resistance ....................... 384 FractunToughness ................................ 384

Fabrication.,. ...................................... 384 Forming ........................................ 384 Heat Treatment ................................... 385

viii

Aluminum Alloy Fatigue Data

Aluminum Alloy S-N Fatigue

Highcycle fatigue characteristics commonly are examined on the basis of cyclic S-N plots of rotating-beam, axial, or flexun-type sheet tests. Many thousands of tests have been performed, and early work on rotating-beam tests is summarized in Fig. 1. There seems to be patex spread in fatigue strengths for unnotched specimens tban for notched specimens. "his appears to be evidence that the presence of a notch minimizes diffwences. thus suggesting similar crack propagation after crack initiation with a sharp notch. In this context, the spread in smooth fatigue life is partly associated with variations in crack initiation sources (at surface imperfections or srrain localizations). In general, however, the S-N approach does not provide clear distinctions in charactenz ' ing the crack initiation and crack propagation stages of fatigue.

When comparing rotating-beam fatigue strength of unnotched aluminum alloy specimens, the S-Nresponse curves tend to level out as the number of applied cycles approaches 500 million. This allows some rat- ing of fatigue endurance, and estimated fatigue limits from rotating- beam tests have been tabulated for many commercial aluminum alloys (Table 1). Fatigue limits should not be expected in aggressive environments. as S-N response c w e s don't tend to level out when comsion fatigue occurs. Rotatingkam strengths determined in the transverse direction arc not significantly different from test results in the longitudinal direction. The scatter band limits in Fig. 2 show relatively small effects attributable to working direction, particularly for the notched fatigue data

Rotating-beam data have also been analyzed to determine whether fatigue strength can be correlated with static strength. From aplot of average endurance limits (at 5 x 10s cycles) plotted against various tensile properties (Fig. 3), there does not appear to be any well-defined quantitative relation between fatigue limit and static strength. This well-known result is common among most nonferrous alloys. It should be noted that proportionate increases in fatigue strength from tensile strengths do appear loww for agehardened aluminum alloys than for annealed alloys (Elg.4). Asimilartrendappearsevident forfatiguestrengthat5x IO'cycles (Fig. 5).

Cmct ot Environment AnoLhu key source of variability in S-N data is environment (Ref 1 -

3). Even atmospheric moisture is recognized to have a corrosive effect on fatigue performance of aluminum alloys. Much high-cycle S-N testing has been carried out in uncontrolled ambient lab air environments, thereby contributing to varied amounts of scatter in existing data. This factor should be recognized when comparing results of different investigations.

Most aluminum alloys experience some reduction of fatigue strength in corrosive environments such as seawater, especially in low- stress, long-life tests (e.g., Fig. 6). Unlike sustained-load SCC. fatigue &gradation by environment may be true even when the direction of principal loading with respect to grain flow is other than short-transverse. Fatigue response to environment varies with alloy, and therefore final alloy selection for design should address this important interaction. When accumulating data for this purpose, it is recommended that any testing be conducted in a controlled environment, and preferably the environment of the intended application. Often an environment known to be more severe than that encountered in service is used to conservatively establish baseline data and design guidelines. Because environmental interaction with fatigue is a rateconmlled process, interaction of time- dependent fatigue parameters such as frequency, waveform, and load history should be factored into the fatigue analysis (Ref 1-3).

Typically, the fatigue strength of thernorecorrosion-resistant SXXX and 6XXX aluminum alloys and tempers arc less affected by corrosive environments than are higher-strength 2xxx and ';Ixxx alloys, as indicated by Fig. 7. Corrosion fatigue performaoce of 7XXX alloys may, in general, be upgraded by overaging to more cornion-resistant T7 tempers (Ref4-9), as indicated by results shown in Fig, 8 and 9. With 2XXX alloys, more corrosion-resistant ~ p i t a t i o n - b ~ T8-type tempers provide a better combination of strength and fatigue resistance at high endurances than naturally aged 'I3 and T4 tempers. However, d- ficial aging of 2XXX alloys is accompanied by loss in toughness withre- sultant decrease in fatigue crack growth resistance at intermediate and high stress intensities (Ref 7,s).

Interaction of a clad protective system with fatigue strength of alloys 2024-T3 and 7075-T6 in air and seawater environments is shown in Fig.

162 103 104 105 I@ 107 i@ iOe cycles

Fig. 1 Comparison of fatigue strength bands for2014-T6,2024-T4, and 707ST6 aluminum alloys for rotating-beam tests. Source: R. Templin, P. Howell, and E. Hamnarm. "Effect of Grain-Direction on Fatigue Roperties of Aluminum Al- loys," AIcoa. 1950

I I I I I I I 102 103 104 106 10s 107 id 10s

Cycles

Fig. 2 Comparison of fatigue strength bands for 2014T6 aluminurn alloy products, showing effects of direction. Source:AS7MPmeedings, Vol64, p581-593

4 I Aluminum Alloy Fatlgue Data

Table 1 vpkal tenrllr proprrtks and Wgue limlt of aluminum alloys

ElonElHonlnSOrnmdk), Ik 1.6 mm 13 mm Fatirue

Ultlmatek~ik strength Telellc YlCM strength (%6 10.) thkk (h In) dlnm cnduram limit(& Alloy Md temper MR w m w ipedmen m ki aueclmen

~

1060Q 1060.H12 1060H14 1 W H 1 6 1060H18 11oo-o 1 IWH12 1 IWH14 11WH16 11WH18 13SM 1350H12 1350.H14 1350.H16 l f B H 1 9 2011-T3 2011-Ta 20144 2014-T4,T451 2014-T6,T651 Alclad 2014-0 Alclad 2014-T3 AlcM 2434-T4, T45 I Alchd 2014T6, T65 1 2017-0 2017-T4, T45 I 201 8-T61 2024-0 2024-T3 2024T4, T351 *T361(b) ALclad2024-0 Alclad 2024-T3 A W 2024-T4, T35 I Alclad2024-T361(b) Alflad 2U24-T81, T851 Alclad 2024-T86 1 (b) m-T6 2036-T4 2117-T4 2123 2 1WT85 1 2214 221&T12 2219-0 2219-T42 221%T31,T351 221PT37 2219-T62 2219-T81, T S 1 22 1 ST87 26 I&T6 1 30034 )03-H12 UX13-Hl4 m H 1 6 3 W H 1 8 Alclad m-0 AIclad M03-Hl2 %lad m H 1 4 Alfled 3003-HI6 Alclad M03-Hl8 3004-0

m 85 95

110 130 90

110 125 145 165 85 95

110 125 185

# 185 425 485 175 435 420

380

470 im 425 420 185 485 470 49s 180 450 440 460 4 s 485 400 340 295

485

330 175 360 3w 3% 415 455 475 440 110 130 150 180 2m 110 130 150 180 2m

. I *

,..

i m

10 12 14 16 19 13 16 18 21 24 12 14 16 18 27 55 99 27 62

25 63 61 68 26 62 61 27 70 68 72 26 65 64 67 65 70 58 49 43

70

48 25 52 52 5 l 60 66 69 64 16 19 22 26 29 16 19 22 26 29 26

m

. a .

...

30 75 90

105 125 35

105 I15 140 150 30 85 95

110 I65 295 310 95

290 415 70

275 255 415 70

315 75

345 329 3% 75

3 10 290 365 415 455 255 195 165

440

25s 75

185 250 315 290 350 395 370 40

125 145 170 185 40

125 145 170 185 70

n5

.,.

...

4 11 13 15 18 5

15 17 20 22 4

12 14 16 24 43 45 14 42 60 10 40 37 60 10 40 46 I 1 50 47 57 11 45 42 53 60 66 37 28 24

64

37 11 n 36 46 42 51 57

6 18 21 25 27 6

18 21 25 27 10

.,.

...

n

43 16 12 8 6

35 12 9 6 5

. I .

... a . .

I . . ... , I .

I . .

I,.

... I , .

21 20 22 10

1 1 1

,,. ... 20 18 20 13

18 19 11 6 6

24

m

,..

.., ... ,,. ... .<. 18

17 11 10 10 10

30 10 8 5 4 30 10 8 5 4 20

m

.I.

.I,

...

.,. I , ,

I . .

45 25

17 15 (d)

m

. I , ... ... (C) 15 12 18

13 m ... ... ... ... 22 22 12 22

19 ... ... ... 1 , 1

... ... ...

... 19

27

8

11

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...

... 1 1 1

.I,

1 1 1

.I.

... 10 40

16 14 10 40 20 16 14 10 25

m

m 30 35 45 45 35 40 50 60 60 ... I,.

I . . ... 50

125 I25 90

140 125

9 , . ... ... ... 90

125 115 90

140 t40 12S

1.1 ... ... ..I

.., I ( .

I25 W C ) 95 90

I03 9 . .

...

... . I ,

1 1 1

.,. 105 105 105 125 50 55 60

70 m .I.

...

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. I . ... 95

3 4 5 6 5 6J 5 6 7 9 9 I,.

I , * ... ... 7

18 18 13 m ia

I , .

. I .

9 . 1

I,.

13 18 17 13 20

18 20

I . .

. I .

( I .

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14 1 Ud)

Wd) ... I . .

I,. ... ... ... IS IS IS 18 7 8 9

10 10 ... . . I

I,,

... ... 14

(continued)

Aluminum Alloy S-N Fatigue / 5

Table 1 Typical tensile properlles and tatlgue llmlt of alumlnum alloys (continue@

xx)4-H32 xx)4-H34 3004-H36 3004-H38 Alclad3004.0 Alclad W H 3 2 Alclad3004-34 Alclad3004-H36 Alclad 3CWH38 3105-0 3 105-H12 3105-H14 3105-H16 3 105-H18 3105-H25 4032-T6 4043-0 4043-H38 5005-0 UX)5-H 12 5005-Hl4 5005-Hl6 5005-Hl8 5005-H32 5005434 5005-H36 5005-H38 UX)M 503MI32 Ms0-m 5050-H36 5050-H38 5052-0 5052-H32 5052434 5052-H36 5052-H38 5056-0 M56-Hl8 MsbH38 5083-0 5083-Hll 5083-HI12 5083-8113 508fH32 x)83-H34 5083-H321, H116 Soa6-0 5086432, H116 5086x34 5086-Hl12 5086-H111 5086H343 5154-0 5154-H32 5154-H34 5154-H36 5154H38 5154H112 5252-H25 5252-H38, H28 5254-0 5254-H32 5254H34 5254H36

215 240 260 285 180 215 240 260 285 115 150 170 195 215 180 380 ... ... 125 140 160 180 200 140 160 180 200 145 170 195 205 220 195 230 260 275 290 290 435 415 290 303 295 317 317 358 315 260 290 325

270 325 240 270 290 310 330 240 235 285 240 270 290 310

no

31 35 38 41 26 31 35 38 41 17 22 25 28 31 26 55 ... ... 18

23 26 29

23 26 29 21 25 28 30 32 28 33 38 40 42 42 63 60 42 44 43 46 46 52 46 38 42 47 39 39 47 35 39 42 45 48 35 34 41 35 39 42 45

20

20

170 200 230 2.50 70

170 2a3 230 250

55 130 150 170 195 160 315 ... .,. 40

130 150

195 115 140 165 185 55

145 165 180 200 90

195 215 240 255 150 405 345 145 193 160 227 227 283 230 115 205 255 130

255 115 20.5 230 m 270 115 170 240 115 205 w ) 250

i m

i m

25 29 33 36 10 25 29 33 36

8 19 22 25 28 23 46 ... .,. 6

19 22 25 28 17 20 24 27

8 21 24 26 29 13 28 31 35 37 22 59 50 21 28 23 33 33 41 33 17 30 37 19 25 37 17 x ) 33 36 39 17 25 35 17 30 33 36

10 9 5 5

20 10 9 5 5

24 7 5 4 3 8

. I . ... ... 25 10 6 5 4

11 8 6 5

24 9 8 7 6

2s 12 10 8 7

.,. ... ... ...

... ... ... ... ... ... 22 12 10 14 17 10-14 27 15 13 12 10 25 11 5

27 15 13 12

17 12 9 6

25 17 12 9 6 ... ... ... ... ... ... 9 ... ... ... ...

... ... ... ... ... ... ... ...

... ...

. . a ... 30 18 14 10 8

35 10 15 22 16 20 16 16 8

16 ... ... ... ... ... ... ... ... .,. .,. ... ... ... ... .,. I..

...

...

105 105 110 110 ... ... ... ... ... ... ... .I. ... ... ...

110 40 55 ... ... ... ... ... ... ... ... ... 85 90 90 95 95

110 115 125 130 140 140 150 150 160

150 160 150

160 145 50

i m

...

... ... 145 160 115 125 130 140 145 115 ... ...

115 125 130 140

15 15 16 16 ... ... ... ... ... ... ... ... . I , ... ... 16 6(d) WJ) ... ...

..I ... ... ... ... ... ... 12 13 13 14 14 16 17 18 19 20

12 22 23 We) We) W e ) We)

23 2W) We)

20

...

... ... 2 1 (e) We) 17 18 19 ?o 21 17 ... ... 17 18 19 20

a)BPeedonM)0,000,000cyclesof~mpletelyrevensedetreseueingtheILR.Mooretypeofmachirseandspecimen.(b)TempersT361andT861were~erly~tedT58 and T86, reepeetively. (c) Baeed an 10 cycles u6ing flanval type testing of sheet specimens. (d) Unpubliehea h a data. (e) Data from CDNSWRCTRBlsQOg, lss4, cited below. (0 T7461, although not previously registered, has appeared in literature and =me specifications a~ "78661. (s) Sheet flexural. Sourcee:Aluminurn Stcvrdorde ond Lhta,AluminumA8sociation,andE. Cz~caandUVassilaroe,ACompilatwnofFat~InformatwnfDrAluminumAlloys,NavalShipResearehandDevelopmentCBn-

(continued)

ter, CDNSWC-TR819409,lSgQ

6 / Aluminum Alloy Fatlgucr Data

Table 1 Typical tenrlle propeHrller and fatigue limit of alumlnum alloys (continued)

Ebnestbn in 50 mm (2 k), Q 1.6 mm 1.3 mm

Ultimate kenrlle rhennth Tmikykldstrangth (VM in.) thlck ('A 10.) dbm endmare Ibnlth) A l b y and temper MPn kaj Mm u swcimen specimen MPs bl

52SW8 5254-H112 5454-0 5454-H32

5454-Hl11 !!454*H112 5456-0 5456.H112 5456-H321,HI16,H32 5457.0 5457-H25 4)57-H38, H28 5652.0 5652-H32 5652-HM 5652-H36

5454434

~ 5 2 . ~ 3 a 5657-n25 s 5 7 - ~ 3 a , HB 6061.0 606 1 -T4, T45 I 6061-T6,%51 Alclad 6061.0 AlcladM161-T4,T451 Alclad6061-T6,T651 60634 6063-Tl 6063-T4 6063-TS 6Q63vT6 6063-T83 6063-TS31 6063mT832 60664 W T 4 , T45 1 W T 6 , r n l 607aT6 6101-Hlll 6101-T6 615 I-T6 6201-T81 6262-T9 6351-T4 6351-T6 6463-TI 6463-TS 6463-T6 7002-T6 7039-T6 7049-T73 7049-Tn52 7050.T735 10, T735 11 7050-T745l(f) 7050.n65 1 7075.0 707ST6, T65 1 7072-Hl4 7075-T73 7076dT6 Akled7075-0 AlcM 7075-T6,T651 7079.~6

330 240 2% 275 305 260 250 3 10 3 10 350 130

205 1% 230 260 275 290 160 195 125 240 3 10 115 230 290 #)

150

185 240 255 205 290 150 360 3% 380 95

220

im

i m

. . I

.<< ... 250 3 10 1x1 185 240 440 415 515 515 495 525 550 230 570

503

220 525 490

I . ,

...

48 35 36 40 44

36 45 45 51 19 26 30 28 33 38 40 42 23

18 35 45 17 33 42 13 22 25 27 35 37 XI 42 22 52 57 55 14 32

38

28

,.. I . ,

.,. 36 45 22 27 35 64 60 75 75 72 76 80 33 83

13

32 76 71

... a , .

270 115 115 205 240 180 125 160 163 255

50 160 185 90

195 215 240 255 140 165 55

145 275 50

130 255 x) 90 90

145 215 240 185

8.5 205 360 350 75

195

2m

# , *

1 , 1

.,. 150 285 90

145 215 365 345 450 435 435 470 490 109 505

435

95 4M) 428

...

...

39 17 17 30 35 26 18 23 24 37 7 23

13 28 31 35 37 20 24 8

21 40 7

19 37 7

13 13 21 31 35 21 39 12 30 52 51 11 28

n

... ,.. ... 22 41 13 21 31 53 50 65 63 63 63 71 15 73

63

14 67 62

..,

,..

10 25 22 10 LO 14 18 .,I

...

.,. 22 12 6

25 12 10 8 7

12 7

25 22 12 25 22 12

20 22 12 12 9

10 12

..,

I . .

,,. ,,. 10

15 , , a

,,. ... .,. 20 14

12 12

14

m

9-12

.,.

...

. 1 1

,.. ... 17 11

13

17 11 10

.,.

. > I

I . , ..* ... ... I , .

1 . 1

.,. 24 22 16 .,. .,. .,< 30 18 14 10 8 ...

... 30 25 17 ,.. .,. ... .,. ... 1 1 1

,.. ... .,, .., e . 1

18 18 12 I , .

. I *

... I..

... ...

... ,,. I . , ... ... .,. ,,, 12 11 12 11 11 16 11 ... .., .,, ... ,,. ,..

145 115 140 140

I . .

( I ,

... l x )

160 1 1 1

...

.,, 1 1 1

110 115 125 130 140

1 1 1

.,. 60 95 95 .,, ... I . ,

55 60

70 70

. a ,

.,.

.,. <I, ... . I ,

110 95 ... .,. a3

105 95

90

70 70

... m

... I . (

.<I

... ( . I

..,

... 117 160 35 Is0 138 .,. ...

160

21 If We) We) ... 1 1 1

1 1 1

W e )

U(e) I,,

P . .

... 16 17 18 19 20 ... .,. 9

14 14 ... ... 9 . 1

8 9

10 10

. I .

...

.,.

. a .

I . .

... 16 14 . I . ... 12 15 14

13 10 10 10

111

... ... ... I,. ... .>. .,I

17(e) 23

5 0 W e ) Wd)

23@

...

. . I

I l 6 6

0

m Notched

-

0 6 16 24 Elongatbn 4D,%

(4

Alumlnum Alloy 8-N Fatlgue / 7

I0 Tensile ykld strength, ksl

lb)

0- 40 60 80

P I Notched

Fig. 3 Plots of fatigue with static mechanical pmpertied for 2014,2024, and 7075 aluminum alloys. (a) Endurance uml t vs. tensile smgth. (b) Endurance limit M. yield smgth. (c) Endur8nce limit vs. elongadon. (d) Endurance limit vs. reduction of area. Sharp mtcb (Kt > 12). Source: R. Templin, F. Howell, and E. HartmaM, "Effect ofGrain-Difection on Fatigue Roperties of Aluminum AUoys,"Alcoa, 1950

6. In seawater, benefits of the cladding are readily apparent. In air, the cladding m l y lowers fatigue resistance.

Effect of M/croporodty* The size of tnicroporosity in commercial products is atTectcd by the

fonningpracesaesusedintheirproduction. Arecentprogram wasunder- taken to determine whetha the fatigue strength a u l d be improv the control of micrqmosity. Becauae the stress conantrations in ucts often nullify the effects of metallurgical differences, the program usedbothunnotchedspecimensandsptcimenscontaininganopenhole.

The goal of the program was to effect change in metallic aircraft life

material miccostructure affects fatigue durability p e r f o m . Various studies have shown that most metal cracking problems encountered in service involve fatigue, Further studies have shown that metallurgical discontinuities and/or manufactwing imperfections often tend to exac- erbate such problems by causing cracks to occur sooner than expected. This program concentrated OIL the initiation and d y growth stages of

assessment methodology throufi quantitative understanQn * g o f h o w

+"3tika of Microporosity" is ndapted from J.R. Bmkenbmugh, R.J. Bucci, AJ. Hinkle, J. Liu, P.B. Magnusen, and S.M. Mixasato, "Role of Microstructure on Fa- tigue Durability of Aluminum A M Alloys," Rognss Report, ONR Contract NooO14-91C-0128, IS April 1993.

501 A

Fig. 4 Fatigue ratios (sndufana limitltemile strength) for aluminum alloys and othermaterials. Source: RC. Varley, The Technology ofAlrcminumandlrs Alloys, Nermes-Buttenvorths, London, 1970

fatiguecracks, whmtfiemajorityofsrmcturallifeisspent, Theprogram had two geaaal objectives: (1) quantifying the effect of aluminum alloy

8 / Aluminum Alloy Fatigue Data

I I I I I 0 loo 200 300 400 5w 6M)

Tensile strength, MPa

Fig, 5 Relationships between the fatigue strength and tensile smngth of some wrought aluminum alloys

microstructure onesrly-stage fatigue damage evolution and growth; and (2) establishing an analytical framework to quantify structural component life benefits mainable through modification of intrinsic material microstructure. The modeling approach taken coupled quantitative characterizations of representative material microstructures with con- cepts of probabilistic hcture mechanics.

Reduced Microporosity Materials. Five variants of 7050 plate were selected to provide a range of microsrmcaues to quantify the effects of intrinsic microstructural features on fatigue durability (Table 2). The first maw, designated“o1dquality” material, was produced using production practices typical of those wed in 1984. The material is characterized by extensive amounts of centerline microporosity. Despite the centetline microporosity, this material still mcets all existing mechanical pmperty specifications for thick 7050 plate. Current quality production material, desigmui “newquality”material, was also used, characterized by reduced levels of centerline microporosity compared to the old-quality material. The newquality material repre8ents the current benchmark for commercially available material. The processing methods used in the pro- dudon of the new-quality material are a result of a statistical quality con- m l effort to improve 7050 alloy thick plate (Ref 10). Material taken from

two plant-scale production lots of each quality level provided the material for this program. Both materials are 5.7 in. thick 7050-7451 plate. Static mechanical property cheracterization of the two 7050 plate pedi- grees showed no signifEant differences in p m e s other than an increase in short transverse elongation for the new-quality material (Ref 38), and both materials meet the AMS material specification minimums. The fact that both materials meet the property requhments of the AMS specification underscores the limitation of existing specifications in that they do not differentiate inbinsic metal quality.

The next material variant of alloy 7050 plate was specially processed to further reduce the amount of centerline microporosity, The process used to produce the material is currently not used for commercial production and involves pmess steps that add to current production costs. The production methods are considered Alcoa proptiemy. This material is 150 mm (6 in.) thick and is denoted “low-potosity” plate.

The fourth material variant was selected to have minimal microporosity and a signifEantly smaller constituent particle distribution than either of the previous materials, yet maintain a thick product grain structure, For this purpose, material was selected from the quarter-thickness plane (T/4) of 150 mm (6 in.) thick plate that was produced from ingot that had controlled composition, which limited the formation of w e constituent particles. Constituent particles in 7050 plate are typically of the types AltCuzFe and MglSi, These form during ingot solidification and are insoluble, so they remain in the material through processing to the final prcdun The mechanical work of proassing may break up the particles, which produces stringers of smallerparticles. This material is denoted “low-particle” plate.

The final microstructural variant of 7050 plate used in this program was selected to have no microporosity and have a refined constituent particle size distribution and refined grain size compared to standard production thick plate. For these characteristics, thinner plate 1 in. thick was selected. The increased amount of deformation required to produce the thinner plate acts to heal microporosity and break up the coarse constituent p d c l e s that are present in the cast ingot Fatigue testing was conducted on the five 7050 alloy microstructural variants used in this study. The fatigue tests included both smooth-round axial stress specimens and flat bar specimens containing open holes, as described below.

Effect of Mcroporosity on Fatigue. Smooth axial smss fatigue tests were performed for both the oldquality and the newquality plate materials. The tests w m done on round bars with a gage diameter of 12.7 mm (0.5 in). Gage sections were sanded longitudinally to remove cir- cumferential machining marks. Testing was done at a maximum stress of 240 MPa (35 hi), a stress ratio R = 0.1, and cyclic frequency of 10 Hz in laboratory air. The specimen orientation was long-transvase &-TI relative to the parent plate. The specimens were removed from the midthick-

I Tests in air

104 105 10s 107 10s 106 107 108 Cycles C y C l e S

Flg. 6 Axial s t m s fatigue strength of 0.8 mm 2024,7075, and clad sheet in air and seawater, R = 0. Source: Ref 22


FREQUENCY: 1100 x r n

- - 5086 5086 mi 7075 2024 .HJd .H38 . i 6 ,173 t 3

Fig, 7 Cornparison of axial-mess fatigue strengths of 0,032 in. aluminum alloy sheet in seawater and air. Source: Ref 22

X2010 7075 X7080 7075 7079 2014 .n .n3 .n -T6 . T6 .T6

Fig. 8 Comprimm of fatigue lives of psurized h y h l i c cylinders in la&- tory aw a d sunuW seacoast environmeno at 80% design shess. sourceS: Ref 3, 31

ness (TD) plane of tbe plate where miropotosity concentration is the greatem (Ref 11). The liferimes of the specimens are plotted in Fig. 10 as a cumulative failun plot, whae the data are sorted in order of ascending l i fehe and ordinate is the percentile ranking of the specimens relative to the total n u m k of Wests. Thus the lifetime corresponding to the 50%

specimens failed prior to that lifetime and half failed at longer lifetimes. The data show that the cumulative distribution of fatigue lifetimes for the newquality material is longer than for the oldquality material.

Fatigue tests were also performed for the old- and new-quality materials using flat specimens containing open holes. Tests were performed at four s m s levels for each material pedigree at a stress ratio of R = 0.1 and cyclic frequency of 25 Hz in laboratory air, As with the round specimens, the specimen orientation was L-T and the specimens were removed from the T/2 plane of the plate. The holes were &burred by polishing with diamond compound prior to testing. The polishing was done only on the corners and not in the bore of the hole, and it resuitedin slight rounding of the comers. The fatigue lifetime data are ploaed in Fig. 11 as an S-Nplot. Also p loW for both materials the 95% confidence limits for the S-Ncurves, The contidenee limits were obtained from a Box-Cox analysis of the data, which enables statistical determination of the mean

point on the osdinaterepments the median lifetime, where half of the

20 5 10

AK. k S I \ , T

Fig, 9 Cyclic stress intensity range, AK, vs. cyclic fatigue aaek growth rate., Aa/M, of laboratory-fabricated high-mngth 7XXX aluminum alloys

1 .o

0.8

f 0.6

i 2 0.4

0'

0.2

0.0 104 lo5 lOe

FaUQue Ilfetlme, cycles

Fig. 10 Cumulative smooth fatigue lifetime distributors for oldqualib aad newquality plate (w text for definitions). Tes6 conducted at 240 MPa (35 ksi) max stress, R = 0.1

Table2 Summary ofthe 7050 p W rnnwialr u8ed In the study of the effect ot mlcroporority on Wgua

10 I Aluminum Alloy Fatigue Data

003

10 I 1 I I 104 id lOe 107 l@

FaU,(igue I M m e , cyck8

Fig. 11 Open-hole fatigue lifetimes for newquality and oldquality plate (see text for definitions). Tests conducted at R = 0.1

1 .o

0.8

0.6

0-4

02

0.0 lo, 10s 10s 107

Fatigue nm, cydw

Fig. 12 Cumulative smooth fatigue life distributions for new-quality and low- porosity thick plate (see text for definitions). Tests cductedat 275 MPa (40ksi) max stress, R=0.1

0 Lowporosity - QS% conf. limits \

25 -

20 000 -

id 10s Id 107 lOe Fatbue lifetime, c y c b

Fig. 13 Open-hole fatigue lifetimo for low-pomsity plate and 95% confidence limits for new-quality plate (see text for definitions). Tests conducted at R = 0.1

* O t 104 10s 10s I 07 1DB

FaUgue lifethe, cycles

Fig, 14 Open-hale fatigue lifetimes for thin plate and 95% confidence limits for new-quality plate (see text for definitions). Tests conducted at R = 0.1

Table 3 Comparison of tho calculated material ftltrgue strengths and imDrovementa in ownhole taiaue for 7050 date Inateflak

Oldquality plate 110 Newquality plate 125 Low-pxority plate 125 Low-panicle plate 150

~ ~ _ _ _ _ _

Tabk 4 Hierarchy of fatlguelnltralng features In 7WT7451 plate ~

Dominant mkrostructudfeatun Smoothktiye

Mo(eriP1 (round ban) O#o-bok htim Oldqualityplate Conwmicroporosiiy Coarsemicrcporosity

Miaoporosity Newquality plate Microporosity Low-pormily place Fine mic?oFOrosity constituentparticles Low-partiekplate ... Orain ritruewe n t i n plate Graln structmdn#lstituent Orsin m w s W

particlea P a r t M

S-N response and the 95% confidence limits (Ref 12). The data clearly show that at equivalent stresses the newquality material exhibited longer lifetimes than the oldquality material.

Cumulative smooth fatigue lifetime distributions were obtained for thenewqualityplateandthelow-porosityplatetestedatamaximumcy- clic stress of 275 MPa (40 ksi), as opposed to the 240 MPa (35 ksi) maximum stress in Fig. 10. The stress was increased over the previous tests because the lifetimes of the low-porosity plate wouldbe too long toprac- tically test at the lower stress level. All other testing conditions were the same as in the previous tests. The fatigue l i fdme data are shown in Fig. 12. It can be seen that the low-porosity plate shows considerably longer smooth fatigue lifetimes than the newquality plate.

Open-hole specimen S-N fatigue results were also obtained for the low-porosity plate for comparison to the new-quality and oldquality plate open-hole S-N curves. The fatigue data are plotted in Fig. 13 along with the bounds for the oldquality and newquality plate determined from the BoxCox analysis. The open-hole data for the low-porosity plate lies within the bounds for the newquality plate. This occurs despite the significant improvement in the smcoth specimen fatigue lifetime for the low-porosity plate. An investigation into the mechanisms for the o b served behavior are given in the following section, “Fractopphy.”


A limited amount of fatigue testing was completed on the low-particle thick plate. Five open-hole specimen fatigue tests were performed at a maximum net stress of 200 MPa (30 ksi). A comparison of the calculated fatigue strengths for the thick plate specimens is given in Table 3.

The final microstructural variant of 7050, the thin plate, was tested using the same open-hole S-N fatigue test conditions as for the other materials. The data are shown in Fig. 14 with the confidence limits for the newquality plate for comparison. The open-hole data for the thin plate are considerably longer than for the new-quality plate.

Fractography of the failed fatigue specimens was performed to identify the microstructural features that affect the fatigue damage process for each of the material microstructural conditions. The fractography was performed using a scanning electron microscope.

As summarized in Table 4, the failures for both the oldquality and newquality materials in both the smooth and open-hole tests were controlled by porosity. The sizes of pores in the newquality material are smaller than in the oldquality material, and hence the fatigue lifetimes are longer. The smooth fatigue failures for the low-porosity material are dominated by pores, which are most often associated with particles. These may have a combined effect on the propensity to initiate fatigue damage. The failure of the open-hole specimens for low-porosity plate

REFERENCES

1. C.M. Hudson and S.K. Seward, ALiterature Review and In- ventory of the Effects of Environment on the Fatigue Be- havior of Metals, Eng. Fmcture Mech. , Vol8 (No. 21, 1976, p 315329

2. "Corrosion Fatigue of Aircraft Materials," AGARD Report 669, North AtlanticTreaty Organization, 1977

3. C.Q. Bowles, 'The Role of Environment, Frequency, and Wave Shape duringFatigue CrackGrowthin Aluminum Al- loys," Report LR270, Delft University of "kchnology, The Netherlands, 1978

4. G.E. Nordmark, B.W. Lifka, M.S. Hunter, and J.G. Kauf- man, "Stress Corrosion and Comion Fatigue Susceptibil- ity of High Strength Alloys," Technical Report AFMLTR- 70-259, Wright-Patterson Air Force Base, 1970

6. T.H. Sanders, R.R. Sawtell, J.T. Staley, R.J. Bucci, and A.B. Thakker, "Effect of Microstructure on Fatigue Crack Growth of 7xxX Aluminum Alloys under Constant Ampli- tude and Spectrum Loading," Final Report, Contract N00019-76-C-0482, Naval Air Systems Command, 1978

6. J.T. Staley, "How Microstructure Affects Fatigue and Frac- ture of Aluminum Alloys," paper presented at the Interna- tional Symposium on Fracture Mechanics (Washington, DC), 1978

are controlled by the Al7CuzFe particles, but one failure initiated at a MgzSi particle. At low stress, two failures are seen to initiate as Stage 1 fatigue cracks. Despite the change in initiation mechanism from the new-quality plate where pores dominated, the open-hole lifetimes of the low-porosity plate and those of the new-quality plate are similar, The limited smooth data for the thin plate show Stage 1 fatigue as the dominant mechanism with one occurrence of initiation h m a MgzSi particle. The initiation mechanisms observed for thin plate in the open-hole test appear to be stress-dependent. Stage 1 initiations occur at the low stresses, with a mix of initiation from Al$uZFe and MgZSi particles at the higher stresses.

The fatigue initiation site characterizations provide an understanding of the mechanisms of initiation and how the material microstructure affects the performance of a material. These characterizations have led to the development of an understanding of the hierarchy of mechanisms that control the fatigue. This information is used as input into probabilistic models that enable prediction of material performance based on microstructure. In addition, this understanding can aid material and process designers in the optimization of alloys for structural longev- ity.

7. W.G. Truckner, J.T. Staley, RJ . Bucci, and A.B. Thakker, "Effects of Microstructure on Fatigue Crack Growth of High Strength Aluminum Alloys," Report AFMLTR-76-169, U.S. Air Force Materials Laboratory, 1976

8. J.T. Staley, W.G. Truckner, R.J. Bucci, and A.B. Thakker, Improving Fatigue Resistance ofAluminum AircraRAlloys, Aluminum, Vol53,1977, p 667-669

9. M.V Hyatt, "program to Improve the Fracture 'Ibughness and Fatigue Resistance of Aluminum Sheet and Plate for Airframe Applications," Technical Report AFML-TR-73- 224, Wright-Patterson Air Force Base, 1973

10. C.R. Owen, R J. Bucci, and R.J. Kegarise, Aluminum Qual- ity Breakthrough for Aircraft Structural Reliability, Jour- nal ofAircmfi, Vol26 (No. 21, Feb 1989, p 178-184

11. P.E. Magnusen, A.J. W e , W.T. Kaiser, RJ . Bucci, and RL. Rolf, Durability Assessment Based on Initial Material Quality, Journal of Tbsting and Evaluation, Vol18 (No. 61, Nov 1990, p 439-446

12. A.J. H i d e and M.R. Emptage, Analysis of Fatigue Life Data Using the Box-Cox Transformation, Fatigu~ and h- ture ofEngineering Materials and Structures, Vol14 (No. 51, 1991, p 691-600

Aluminum Alloy S-N Data Aluminurn and 3300( Alloys

cydes to f W @ , N

Anial 0.1

Axkl 0.1

Axll 0.1

Axial 0.1

Axirl Q1

Axirl 0.1

AM 0.1

AM ai Axial 0.1

h i d 0.1

Axial a1 llxfal 0.1

Axial at Axirl 0.1

Axial 0.1

Axial 0.1

Mal 0.1

Air

Afr

Air

33% NSQ

33% N&l

3.5% NaCl

Air

Alr

Air

3 J % W

3.5%NsQ

33% Nacl

Air 3.5%N&1 Alr

3.59bNsQ

A&

...

...

...

...

...

...

...

... * . a

..I

...

.<*

... ... 6..

...

...

...

...

...

... 6..

...

...

...

.,*

...

.a.

. * a

... ... ...

...

...

t , ., . . , ,

i k"' "'

.........

2014115


& i ! d ~ , r u ~ t i "A 1 1 . 4 . 1 ......A . . .

10 log rd 104 id 1d 10' 1d 1 cvcbs

Rig, 7 2014T6 ~nn~tched axial f a t i p . Solid s@h irdicpte m t (XI failure). Urmoochod uial specimsDs with 9-7B in. surface rrdius and aminimum di- ameterof0.160or0.200in. solace: Alcoa 1955

2017117


Minhnum etmw In We. kd

* -300 400 .lo0 0 la0 m 300 i M i m u m atnu in Wde, MPa

Fig. 10 2024-T3 modified Goodman diagram (bare and Alcladsheet). Source: Alcoa, 1957

2024-T3 sheet: Room4empemture fatigue strength In air

20 40 / ‘ I

// .

..... . .

A 6 X 1 d 1 ! 1

20 / Aluminum Alloy Fatlgue Data

F'ig. 13

FFlTIGX LIFE, CYCLE

2024-T4 notched axial fatigue (Kt = 3.4) from bar in longitudinal direction. Source: MIL-HDBKJ

- a a

5 00 E c

X Y

G W

400 t & 5 2 300 Vl

K I- VI

2 00

! I ' 3- 3..

+ k

10 3 10 4 to 5 lo6 10 7 C Y C L E S TO F A I L U R E N F

fig. 14 2024-T4 notched rotating beam fatigue (Kt =2.1) for rolled, shot peened (SP), and electrolytically polished (EP) specimens cut from plate in longitudinal direction. Notched specimens were surface rolled usinga Ihree-roll device with an optimum rolling force of 0.8 W reported by L. Wagner etd., Influence of Surface Rolling on Notched Fatigue Strength of A1 2024 in Wo Age Hardening Conditions, Faliguc 93, MCPE. Figure source: Su&c Engineering, DGM, 1993

-1.00 4.50 01x) 0.06 0.50

-1.0

ON

0.4

-1 -0

0.06

0.46

-1.0

0.06

0.46

0 0

-1

-1

... , a * ... .I. ... ... ... I..

... 4. .

* , a

.,.

...

.I.

.I. ...

...

...

22 I AIumlnum Alloy Fdgue Data

0 Unnotched A N o t C h d

Wld symbals, runout 0 0 0

0 00 0

cv- 17 2024.T6 rotating beam fatigue for motched and notched specimens

from exmsion and rolled-and-drawn rod (radius at notch root 4.001 in.). R.R. Moore specimens with 9-718 in. surface redius and 0.300 in minimum dianaeter forurnsotchedspecimws. Notchbdspecimenihada0.330in,diamehratthenotch and a 0.480 in. diameter outside the 600 notch Solid symbols indicate mnout (a0 failure). S o w : Alcoa, 1954

2024-m extrudd rod: Rotaing berm fatlgw strength in air at mom tomperaturo

2024-m 4361 and -T361: Room-l*mpmhrn fatigue stmngth in air

I ..A . I . ..... -1 . , . . 4 ..

109 10' lo6 loe 10' 10e log loio Cydes

Fig. 18 2026~and202eT4mtatingkamfati~farurmotchedandnotc~ s p e c i m from 5/8 In. plate (radius at notch root 4.001 in.). R.R. Moore s p i - m m withP-7/8ir~srtrfaceradillsaad0.300in. minimumdismeterforuotckd s p e c i m . N O W spechms had a 0.330 in. diameta at& notch and a 0.480 in. d i m outside tbe #' notch. Solid symbols indicate Nmut (no failure). s0urce:Alcoa 1962

wl= m20 2024-TS52 rotatingbeamfatiguefofurmolebedaudnotched~pecimens from web and h p sections of die forgings (radius at notch root d.001 in.). RR. M o m specimens with 9-7B in, surface radius md 0.300 in. minimum diameter for pnnotched specimens. Notched specimens had a 0.330 in. diameter at the notch ad a 0.480 in. diameter outside the 600 notch. Solid symbols indicate runour (no failure). M lines an for 2024-T851 pnfocged plate, 1.5 to 5 in. thick S0urce:Alcaa

24 / Aluminum Alloy Fatigue Data

Minlmum stre&¶, kr l

Fig.21 2024-Ts51

Flg, 22

a -200 -100 0 100 200 3M) MHmum am=, MPa

Fig. 23 2024-T85 1 notched axial fatigue (Kt = 4.4. r= 0.005 in.) at mom temperature (7/8 in. plate)

-200 -100 0 100 m 300 MHmm (tM* MPa

Fig. 24 2024.T851 notched axial fatigue (Kt = 4.4. r = 0.005 in.) at 150 OC (3W OF). Source: A h a , 1965

26 / Aluminum Alloy Fatlgue Data

~

21247351 mnd -TS51 plate: Rom-tempersture fatlgue strength in air

Test stress Fatime strength (hi) at mles oh P m w r SlKClmeO mode ratb l@ 106 10' lol 5 X 1 d T35 1 RWnd Axial 0 T85 1 RRMwR Rotating bcam - I

RR Moom notch Rotating beam - I RoUnd Axial 0 Roundnotch, K,= 3 Axial 0

Source: Unpublished A h a data

221aT8 and -TB / 27

OF . . . . * . . . . ....: * . . ....a . * . . ....' . . . JJ I

lo4 id 1 00 lo7 iOe 1 C Y C b

Fig. 25 2219-TS unnotchcd axial fatigue at morn temperature (plate, L, LT, ST). Unnotched axial specimens with 9-7/8 in. surface radius and 0.300 in. minimum diameter, Solid symbols indicate runout (no failure). Som: Akoa, 1965

CYdeS

Fig. 26 2219-T8 aotched axial fatigue (Kt > 12) at room tempmure (plate). N O W axial epecimew with 0.300 in. diameter a& the -and a0.360 in dhm outeide the 60" notch. Solid symbols indicate runout (1y1 fdfurc). Source: Alcoa, 1965

01 . . ~ ~ I . . ....._I . . ....._I . . . ..._ J . . .._..a . . .

cycles

Fig. 27 2219-T8 rotating beam fatigue for unnotched and notched specimens at rwm tempsrature from plate, forgings, fad axtnrsions (radius at notch mot 4.001 in.). R.R. Moors specimens with 9-7/8 in. surface radius and 0.300 in. minimum diameter fbr motched specimens. Notched spcimens hada 0.330 in. diameter at the notch aud a 0.480 in, diameter outside ths 600 notch. Solid sym- bob indicate runout (no failure). Source: AlCOa, 1965

2219 Hbh-tomDemture fatbue atremath In rlr

bum: Metalr m, Sept 1961


4 0

i 4M) -2m -100 0 I#) 400

Minimum strew, MPa

Fig, 28 2219-T87 unnotched axial fatigue at m m temprum (1 in. plate). Source: Alcoa, 1964

Joo .200 -1 00 0 I#) #XI 300 MnbMnebp9,m

F%. 29 2219-T87 notched axial fatigue (Kt = 4.4. r = 140.005 in.) at mom temperature. Source: Alma, 1966

Fig. 30 2219-T87 unnotched axial fatigue at 150 O C (300 OF) (1 in. plate). Source: Alcoa, ,1966


MHmmmu.bl

Fip.31 2214.T87

A Notched a 3 -2218 band (rmooih)

- - 2 2 1 9 b a n d ( W Solid ryrnm, r u m d

CVM

-32 2219.T87 notchcd(dusatnotchrwt4.001 in.)andunnotchedrotat- ing bearn fitigue @he). R.R. Moon specimens with 9-7B in. surface radius wd 0,300 ia. minimum diemeter for unaotched specimens. Notched spechens had a 0.330 h damcter at the notch and a 0.480 in. diameter outside tbe 60' notch. Solid symbols indicate ruaout (no failure). Bawl linm are for 2219 products in v a r i w tempers except annealed,

2219T851 I31

-400 -300 -200 -100 0 100 200 i Mhlmum alnru, MPa

Fig. 33 2219.T85 1 unnotched a x i ~ l fatigue at r w m temperature (1.25 in. plate). Source: Alcw 1966

Minimrvn mss, MPa

F&g. 34 2219-T851 notched axial fatigue (Kt = 4.4, r = 0.095 in.) at room temperature. Source: Alcoa, 1966


0 40

0 100 200 Minimum slma, MPI

221PT85 1 notched axial fatigue (Kt = 4.4, r = 0.005 in.) at 150 'C (300 O F ) . S o w : Alcoa, 1%

261 &T6 end =T651 I33

34 I Alumlnum Alloy Fatigue Data

3xxx and 4xxx Albys

H I I

rod 104 106 10' 10' id 10s cvcles

Fig. 37(4 3003-Hl6 ulurotehd rowing bearn fadgue at rwm temperature (1 and 118 in. rod). Unnotched axial specimens with 9-7/8 ia curface radius ard 0.3Ooin. minimum diawtsr.

m Rg. 37(c) 3003-H.24 mhed and unaotchcd nxadng beam fadpe at mrn tan- perrtnre (0.75 in. rolled and drawn rod). Radius at notch root was <0.001 in. for notebed s p d n c ~ . RR. M o m sphm with P7/8 in. surfax radius and 0.3Ooiamioimumdiametafor~tchedspecimenr.Notcbedspccimenshsda 0.330 in. diameter at the notch cmd a 0.480 in. diamctsr outside the W notch, S0Utw:AlCOa

5008$11(1 Rod Q Unnatohed

. . . . -

A 0

............. ".........I.... ......... 1. .A,, ... ......-1.

. . . . . . . . . . -

............. ".........I.... ......... 1..d ..... ......-1.

b A h

A A A

Fig. 37@) 300SH18 notched and unnotched rotating beam fatigue at loom tem- penturs (0.75 in. rolled and dnwn rod). Radius at notch root wpll<0,001 in fm notchedqecimm. R . R . M o a r s s p e c h with9-7/8in.surFrrtradiussand0.300 in. minimum diameter for unnotchsd spechem, Notched ipecimsnS had B 0.330 in. diameter at thenotch aada 0.480 ia diameteroutside thaw W. Souroe: A h

~

0 ...... 4 ..... ..a ...... 4 . . ....., ...... i . . . 18 loa 104 td t d 10'

cvcler, mg. 37(d) 3003.0 UnnOtche4 axial (R = -1) d rotating bcam (R =-I) fatigue (0.75 in. diun rolled ud drarm rod), Unnotched towing beam specimem with 9-7/8 i n surface radius and 0.300 in. minimum dirmsbr. Urmotched axial spsci- mcp8 with P7/8 in. surface redius wd 0.200in. minimum diameter. Source: Al- COB

O U n r o W l e d A N o l c h e d

3

, , . . . . . , . . . - 0 ....

i 1

L I

F¶g. 3 7 0 m H 1 8 notched and unnotcbed rotating beam fadgue at morn tun- pslatllre (0.75 in dim rod). Radius at notch mt was Q.001 in. for notched specimens. R.R. Moore spedmws with 9-7B ia sdm radius d 0.300 in m i n i m u m d i a m e t e r f o r ~ s p e c h m . Norchsdspedmembada0.330in. diamematthe notch anda0.480 in. diamaerorrtside ths 600 mbch. Solid symbols indicate runout (w failwe). Swce: A h

36 / Alumlnum Alloy S-N Fatigue

. . . '.....A . . . . . . . . . . . . . . . . 102 id id id 14 10' id

CYdeS

Fig.370 UX)4-H34notebsdllndmmotc~~gkamfatiguerrtmmtsm- peratwe (0.75 in. dim rod). Radius at notch root w a 4.001 in. for notched Specimws. R.R. Moon s p s c h with 9-7/8 in &a# radius rmd 0.300 h minimurnclheterforunnotchsd,~.Notcbedspecimerts hada0.330ia. diameter at tbm notcb md a 0.480 IIL dmmctcr outside the 60" a h . Solid tym- W s indicate m u t (no failure). Source: Alcoa

50 so&+rsoFmd

O UnMtehed - ... .............. . . . . . . . . . ...... ................I I..,," I "Notohed

a

I . . ..- . . . los id id id 10' 10'

crcles

peratun (0.75 in. diua rod). Radius at nacb root was 4.001 h for notched

minimum diamstsr for urmMcbcd spccimsns. Notched spechem bad a0.330 ih dimemat the notch aad a 0.480 ia. diamctermgide the 600 notch. Solid rym- boLS indicate nmout (no failure). Source: A h

Fig. 37@) W H 3 9 Wkd and Unnotched m u q bsam f i t i g ~ at tsm.

~peeimens. R.R. M m rpbdmaa with 9-7/8 iU 8 h &UP md 0.300 h

4- and 5xxx Alloys

50

_. ..............................

3 - ~ - - ~

lao. * \ I 3 20

-.... . .............. I

to - ......... i. .................

0 I

1 o3

1 0' lo6 1 oe 1 o7 10B 1 og cycles

Rig. 3(m) 4032.- lmmtched rotating beam fatigue. R.R. Moore specimens with 9-7/8 in. surfax redins dO.300 in. minimum -for urmoscbed Specimeas. s0urce:AlCoa

38 I Aluminum Alloy $44 Fatlgue

20

15

I ' 5 : 9 10- 5 - B :

0

4043 Rod - Unnotched rotating beam - 120 0 4043-0

0 W H -100

No failure, 2 testa

UTS: 15.1 ki I 34% ebnongabn

UTS: 27.1 ksi / 6.76% etongeHon

-

1" I - 9 B 0 f

-40 5-

.) - 20 -

I 1

Fig, 37(11) 4043 unmtched rotating beam fatigue (0.75 in. dim rod). Source Alcm

5050: Fatigue strength In ak

0

H38 H38

Plate P k P k Plate Rod Rod Flate Plate piace Plate Rod Rod Plate plate plate Plate Rod Rod

Cantilevabeam cantilever beam cantilever beam cantilever bun RRM- R R M m , nmhed Kt = 12 cantilever bean cantileverbeam cantileverbem cantilever beam RR Moore R R M ~ t ~ , W ~ h e d 4 = 1 2 centileverbeam cantilewbeam can t i l ewkam cantilevakam RRMowe RR Mom, notched Kt = 12

-1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1

&urcee:Unpublbhedh dataandM.G.Vdarcd andEJ. C~mca,Ns~ReeearohLebReportCDN9WCTR819409,ACompil.tlonofFatiOueInswmcltionforAlu- minum Alloys, lsgq

H16

H 18

HI8

Srmrces: Unphlbhed Aha data and M.G. Vaedilm and E J. Cqrrgea, Naval Reeearch Lab Report CDNSWGTRBl&OD, ACompi lahof Fatigue krtormationfor Alu- minum Auoys, 1 w

40 I Aluminum Alloy 8-N Fatigue

5052432 and -HM: Fatigue strength In varlws onvlronmnts

Mnmum@?ew,MR

I Q , 38 5052-H36 (52S-H36) unnotched axial fdgue at room temperamre.. S o w : Ala~a, 1952

5052438: Roommwntum fatlaw menath In alr

Flat plate Flat plate Flat plate met plate Fla~ plate 0.330 in. diam 0.330 in. dm. 0.330in. d i m RRMom RRMoar, nached Kt = 12 Rimnd

Axial Axial Axial Axial Axial A l m i n g torsion Altcmting torsion Allanating tonion - g b - g b Axial

to3 0

-05 -1 -2 40.5 0

-1 -1 -1 0 43 -1.0 -2,o

09) ..I

I.,

I . . ... ...

... ... ...

6062-H38:Fatigue strength in alr at varkur Wmpsretursr

-300

Fig. 39 5053-T6 (S3S-T6) rmnotched axial fatigue at room mpcratwc.Swrce: Alcoa 1952

42 I Aluminum Alloy 5-N Fatigue

i 4 0 -

f E af j 20-

10-

O Unnotched * Notched

I

ol . '.'..'A ' .."'a ' ' . . . . . A ' -.'.'a ' ' ' . I _."'* ' L .

Cycles

Fig. 40 5056-H32 and -H34 notched (radius at notch mt 4.001 in.) and unnotched rotating beam fatigue (314 in. rod rolled and drawn). R.R, Moore specimens with 9-7B in, surfece radius and0.300 in. minimum diameter for unnotched specimena. Notched specimens had a 0.330 in. diameter at the notch and a 0.480 in. diameter outside the 600 notch. Source: Alcoa, 1%1

5058: Fatigue strength In alr at varkus temperature8

Prnw thwQcE? Specimen mode ratb F (OR lo' lo( 106 107 105 5x108 F o m and l b t Bhtar 'DempcrPtum Fathwstmngth (ksl)stryelesofi

0 mete cantilever

m 2 P h carltuem

H34 Plate Cantilever

H32

H34

0 Rod R . R M o o n , unnorched

R.R M m e , nmhed, Kt = 12

Rcd R.R.Mane, unnotched RR. Moore.

Rod RRMoae, UnnaChed

R.R. MoaE, notched, Kt 5 12

naclled,Kt= 12

Bending

Bending

Bending

Rotating beam

Raatingbeasn

Ratatingbeam

Routing beam

Rotating ham

Rotwing beam

-1 24 O C (75 OF) 15OoC(XU!"F) 200 OC ( 4 O o O F ) 260T(500OR

l M ° C (300 OF) 2MI0C(5W 'F)

-1 24 "C (75 OF)

-1 U"C(750F)

6 o w m Unpubliehed Alma data; M.G. Vaseilarcrs m d E J. Czyyoa, Naval Research Lab Report CDNSWCTR619409, ACornpiktion CaFatkgw Information for Alumi- num Alloys, 1994

5082-Hll: Room-temperature fatlgue StnnQth In air

9i in. phte % in. phts !$ in. pi&

b$ in pkte

%inplate

I / r in. p k

'/r in p h e

V4 in plate k in. plate 34 in. plate 9, in. plate

Ha@

%in. phte

h in, p k

9i in. plate

!+ in. phie

RR Moore Fiat plate Plat plate, % in. machined from

Flat- I& in mhlnedfrom one surface

bothsulfacer

f d k , beadsn Longitudinal. bun weld, 5056 filk budsff

Transverse bun weld, 5056 filk, teadsff

As above but bead.on R R M W lhnsverse bun weld, 5056 filler As above but hest a f f d a ~ a e

Dar& fillet of 5056 filkr, welds

Longitudinally fillet welded

Longitudiaally fillet welded

Longitudinally Rlk welded

As & w e but with 4043 fllk

h g i t u d i l d butt Weld 5056

taersed

parallel to stress

beams, 5083 filler

beamp, 5083 filla

beams, 5083 filla

Rotating h Revased plane bending Reverred p l m bending

Reversed plaw bending

Reversed plpae buding

Rcverred plane bending

Revclsed plane bending

Rrverred plane bending Rmtingbbam Rotering beam Wngh

Reversed pkne

Plane bending 3. p i n t

PIam bending 3- point

Pbne bending 3. point

plpne kndiag 3- point

bending

bad

loall

Iced

load

-1 - I -1

-I

-1

-1

-1

- I -I -I -I

-1

.5

0

-I

-1

(23) ... ... .I.

...

...

... b..

W) (14)

(17.9

.I,

...

...

...

...

44 I Aluminum Alloy 8-N Fatlgue

I Spiral Scratch - 0.003511 deep 0 Vee Notch - Hoot Radius 0.00211 - Kt = 6 . 3

A Vee Notch - Root Radius 0.008" - Kt = 3 . 5

Vee Notch - R o o t Radius 0.0121t - Kt = 3,2

No, of Cycles t o Failure

Fig. 41 5M3-Hl1 rotating bending fatigue with rnachinednotches and spiral scratches. Source: Naval Research Lab Report CDNSWC-TR619409.1994

(continued)

Next Page

Magnesium Alloy Fatigue Data

Magnesium Alloys Fatigue and Fracture*

Magnesium possesses the lowest density of all snuctural metals, havingabout259gthedensityofironandapproximately3344,thatofalu- minum. Because of this low density, both cast and wrought magnesium alloys have been developed for a wide variety of srmctural applications in which low weight is important, if not arequirement.

Magnesium and magnesium alloys are used in stnrcnual applications for automotive, industrial, materials-handling, commercial, and aerospace equipment. In the aerospace market, air frame applications in new designs have virtually disappeared and tbe m s t significant use of magnesium alloys has been m n f i i largely to cast engine and transmission housings, notably for helicopters, Historically, the Volkswagon Beetle motor c a ~ has represented the largest single application of magnc- sium alloys, which were used for cmk case and transmission housing castings that weighed a total of 17 kg. This was said to represent a saving of 50 kg when compared with using cast iron and was critical forthe stability of this w-engined vehicle.

Moro recently, weight reduction by material substitution is an application area for increased automotive fuel economy and reduced exhaust emissions. This is the purpose, for example, of the U.S. Corporate Aver- age Fuel Economy (CAFE) legislation, which requires manufacturers to achieve progressive improvements in the fuel economies of vehicles they produce, and which is providing much of the stimulus to programs of weight reduction through materials substitution, Table 1 presents a se lection of magnesium alloy components in various new production v e hicles. The other major area8 in which the use of magnesium is expand- ing are appliances and sporting goods. The trend here has again been for an increase in the use of magnesium die castings, for example in computer housing and mobile telephonecases where lightness, capability for thin-wall casting, and provision of electromagnetic shielding are special adVantageS.

This inlmhctory article briefly reviews the physical metallurgy, alloy types, and fatigue and fracture toughness of magnesium alloys. The

Table 1 &Mion of magnesium alloy cmpnenta In new pmdw tlon mQtorcam and truck

Cornmay Ford

mrt Mow ALbv Clutch housing, oil pan, Ransa Az9lHP

lteering column AZ91B Follr-wheel drive !nnskmse Amstar 1% AZOlD

AZ91D bins

Maauai rransmission cm B m

valvecovFf,aircbBryT, corvette AZ91HP

MuctioncWU NonhStarV-8 1992 AZ91D

hwing

clutch horuing (manual)

M n g column brackets Pontiac, Bulck Clutch pedal, brake pedal, “W Oldmobile, AZ91D

Drivchkeer, oil paa Jcep 1993 ,,. Saeaingcolumnbtackets LHhiiUpc 1993 .,. Driwbncks, oil pan vrper seatframos So0 SL Mircellaneouscomponems on AZ91B

Mi-components 911 ..I

wheels (7.44kgaach) 944Turbo A S I D Cylinder head cover City Turbo AZ91D WWls(5.9kgeseh) Rehlde AM6OB Steaing wheel h u s AM608 Cylinda block, oil sump, 5HQ AZ91E

Zt?&lA

1 1 1

WWSO

(45 Lrg)

(53 kg)

CMISheft COW, front cover ~~d 4 a*semblY Amtech ZC63

sections on fatigue and fracture toughness in this article provide a general overview, while subsequent articles are compilations of a l loy -w cific fatigue data.

The discussions on individual alloy systems of practical importance focus mainly on casting alloys. However, some new devciopments involving novel magnesium-base alloys prepared by rapid solidification processing, and maal matrix composites, arc also considered. In al l cases, special emphasis is placed on relationship between micn>smr~- are and properties. A more general account of the metallurgy of magnesium alloys is given in the classic book by E m l 9 (Ref 1) and develop- ments in alloy theory are discussed in Ref 2 to 4. Microstructursl featuns are considered in more detail in the recent book by Polmear (Ref 5). Spe- cial attention to properties and the design of magnesium prcducte, is given by Busk (Ref 6). The ptoceedings of arecent comprehensive con- f m c e on magnesium alloys are atso available (Ref 7).

Alloy Designations and Tempera No international code for desig- nating magnesium alloys exists, although there has been a trend toward adopting like method used by the American Society for Testing and Ma- terials. In this system, the first two leaers indicate the principal alloying elements according to the following code:

.

.

. *

* 0

. #

A4uminum B-bismuth c--coPper -urn E-rare earths F-iron H-thoriUm K--zirconium L-lithium M--manganeee N-nickel P-lead Q-silver R--chnmsiUm S-ailicon T--tin

Y-antimony z-zinc

W--yttrium

The letter corresponding -3 the elemen- present in greater quantity in the alloy is wed first; if the elements are equal in quantity the letters are listed alphabetically. The two (or one) letters are followed by numbers that represent the nominal compositions of these principal alloying elements in weight percent, rounded off to the nearest whole number (e.g., AZ91 indicates the alloy Mg-gAl-lZn, the actual composition ranges b i n g 8.3 to 9.7 wtk Al and 0.4 to 1.0 wt%

*Adaptedfromthe followingarticles: I.J, Polmeat,MagDedumAlloysandAppli- cations, submitted for publication in the Materialr Prqpcnies H a n d h k series, ASM Intemational;G.L MakarandJ. KNger, CorrasirrnofMagnesium,Intema- tionaLMaterialr Review, Vol38,1993, p 138-153:and W.K. Miller, Stress C m sion Cracking of Magnesium Alloys, Slnsa-Corrosion Cracking: Materids Per- formance and Evaluation. ASM International, 1992.

118 I Megneslum Alloy8 Fatlgue Data

Zn. A limitation is that information concerning other inten- tionallyaddedelementsisnotgiven,andthesystemmayneed to be modified on this account. Suffix letters A, B, C, and so on refer tovanations in composition and puritywithinthe epeci- fiedrange, andxindica tes that the alloy is experimental.

For heat-treated or work-hardened conditions, the designations are specified by the same system used for aluminum alloys. Commonly u d tempers are T5 (alloys that were artificially aged after casting), T6 (alloys that were solution treated, quenched, and artificially aged), and '17 (alloys that were solution treated and stabilized).

In contrast to aluminum, magnesium has a close-packed hexagonal crystal stntcture, with parameters of a = 3.202 A, c = 5.199 A, and c/a = 1.624 A (which is very close to the ratio of 1.633 obtained by piling spheres in the same arrangement). This structure is basic to much of the physical metallurgy of magnesium and magne_sium alloys. At room temperature, slip occurs mainly on (OOOI) (c1 l20>1, with? small amount sometimesseenonpyramidalplanessuchas (1011)c1120>. Asthetem- perature is raised, pyramidal slip becomes easier and more prevalent. However, note that the slip directions, whether associated with basal or the pyramidal planes, are coplanar with (OOOl), ageneral observation for all observed slip in magnesium and magnesium alloys. Therefore, it is impossible for a polycrystalline piece of magnesium to deform without cracking unless deformation mechanisms other than slip are available. These mechanisms are twinning, banding, and grain-boundary defonnation

Another key feature that dominates the physical metallurgy of magnesium alloys is the fact that the atomic diameter (0,320 nm) of magnesium enjoys favorable size factors with a diverse range of solute elements, In this regard, atoms with sizes that place them within the favorable *15% range with respect to magnesium are shown in the shaded band in Fig. 1 (Ref 8,9), Further restrictions in solid solubility are imposed through differences in valency (relative valency effect) and becauseofthe chemical affinity of the highly electropositive magnesium with elements such as silicon and tin, which leads to the formation of a number of stable compounds.

Aluminum, zinc, cerium, yttrium, silver, thorium, and ziroonium are examples of widely differing metals that may be present in commacial alloys. Apart from magnesium and cadmium, which form a continuous series of solid solutions, the magnesium-rich sections of binary phase diagrams (Ref 10, 11) show peritectic (or, more commonly, eutectic) systems. Of the wide range of intennetallic compounds that may form (Ref 3,4). the three most Frequent types of structures are:

AB: Simple cubic CsCl structure. Examples are M f l , MgAg, CeMg, and SnMg. It will be seen that magnesium can be either the electropositive or ellectronegative component. AB2: Laves phases with ratio RA/RB = 1.23 preferred. Three types exiat: MgCu2 (face-centered cubic, stacking sequence a h b c ) , MgZnz (hexagonal, stacking sequence ababab), and MgNh (hexagonal, stacking sequence abacaba). CaF2: Faceantered cubic. This gmup contains Group IV elements, examples are MgzSi and MgzSn.

Another characteristic of alloy systems in which solubility is strongly influenced by atomic size factors is that solid solubility generally decreases with decreasing t e m p m r e (Ref 10). Such a feature is a necessary requirement for precipitation hardening, and most magnesium alloys are amenable to this phenomenon, although the responses are significantly less than is observed in some aluminum alloys. Precipi- tation processes are usually complex (Ref 5) , and a feature common to

o

o

I I I I 1 I I I I I I I 1 1 - 1 1 - 1

0.5

0.4 E 6 z *L! a 0.2

a 0.3 u

e

0.1

0 10 20 30 40 SO 60 70 00 90 100

Atomic number Fig, 1 Atomic diameters of the elements and the favorable size factor (shaded area) with respect to magnesium

Magnesium Alloys Fatigue and Fracture / 119

Alloy system Precipitation procew

Mg -R E( Nd )

Me-Y-Nd

Mg-Th

MQ-AQ-RE(Nd)

M B a Th? w, { W z T h hCP (i) j, hexagonal fcc DOts superlattice (ii) 6; fcc a= 1.43 nm discs/l{l OTO}M. (both semicoherent) (incoherent)

} / 'MgnThe

(coherent) - GP zones hexagonal l ( w o 1 )Mg rods (coherent) a = 0.963 nm

c = 1-024 nm

(coherent)

GP zones hexagonal 11 ( m l )Me equiexed hexagonal (coherent) a = 09658 nm laths

' Y SSSS - Rodlike

I1 to [00011M,

b M g t z N d A complex

SSSS - Ellipsoidal : 8

(eemic6herent)

SSSS supersaturated solid solution.

Fig. 2 Robable precipitation pmesses in magnesium alloys. Source: Ref 5

most is that one stage involves formation of an ordered, hexagonal pre cipitate with a Do19 (Mg3Cd) structure that is coherent with the magnesium lattice (Fig. 2). This structure appears to be analogous to the well- known 8" phase that may form in aged AlCu alloys, and it appears to be present when alloys show a maximum response to age hardening. The DO19 cell has an a-axis twice the length of the a-axis of the magnesium matrix, whereas the c-axes are the same. The precipitate forms as plates or discs parallel to the 4 0 0 1 ~ , directions, which lie along the

(ioio)Mgand_{ 11%}W~1anes. Inthisregarditissignincanttonotethat alternate (1010) and (1 120) planes in a structure of composition Mgfl consist entirely of magnesium atoms. Thus, the fonnatiw of a low-energy interface along these planes is to be expected, because only second- nearest neighbor bonds need to be altered. This structural feaaue could account for the fact that the phase is relatively stable over a wide temperature range, end it seems likely to be a key factor in promoting creep resistance in those- magnesium alloys in which it occurs.

Cast magnesium alloys have always predominated over wrought alloys, paxiicularly inEurope, where traditionally they have comprised 85 to 90% of all products. The earliest commercially used alloying elements were aluminum, zinc, and manganese; the Mg-Al-Zn system is still the one most widely used for castings. The fmt wrought alloy was Mg-lSMn, which was used for sheet, extrusions, and fo@ngs, but this material has largely been superseded-

Early Mg-Al-Zn castings suffered severe corrosion in wet or moist conditions until the discovery in 1925 that small additions (0.2 wt%) of manganese increase corrosion resistance (Ref 12). The role of manganese was to remove iron and certain other heavy metal impurities as relatively harmless intermetallic compounds, some of which separate out during melting. In this regard, classic work by Hanawalt et al. (Ref 13)

showed that the corrosion rate increased abruptly once so-called "tolerance limits" were exceeded, which were 5, 170, and 1300 ppm for nickel, iron, and copper, respectively.

Another problem with earlier magnesium alloy castings was that grain size tended to be large and variable, often resulting in p r mechanical properties, microporosity and, in the case of wrought products, excessive directionality of properties (Ref 1, 12). Values of yield strength also tended to be particularly low relative to ultimate tensile strength (UTS). In 1937, Sauerwald in Germany discovered that zirconium had an intense grain-refining effect on magnesium, although several years elapsed before a reliable method was developed to alloy this metal. Here it is interesting to note that the lattice parameters of hexagonal a-zirconium (a = 0.323 tun, c = 0.514 nm) very close to those of

120 / Magnesium Alloys Fatlgue Data

magnesium (a = 0.320 nm, c = 0.520 nm). This suggests the possibility that zirconium particles may provide sites for the heterogeneous nucleation of magnesium grains during solidifgation. Paradoxically, zirconium could not be used in most existing alloys because it was removed from solid solution because of the fmat ion of stable compounds with aluminum and manganese. This led to the evolution of a completely new series of cast and wrought zirconium-containing alloys that were found to have much improved mechanical properties at both room and elevated temperatures. Such alloys are now widely used in the aerospace industries. Compositions of the major commercial magnesium casting alloys arc shown in Table 2. The zirconium-& and zirconiumcontaining series of alloys are considered separately below.

Zirconium-Free Casting Alloys Alloys Based on the Mg-Al System. The binary Mg-AI system was

the basis for early magnesium casting alloys. The maximum solid solubility of aluminum is 12.7 wt% at 437 "C, decreasing to around 2% at room temperature (Ref 10, 11). In the as-cast condition, the Pphase Mgl7A112 forms around grain boundaries, being most prevalent in more slowly cooled sand or permanent mold castings. Annealing or solution treating at temperatures around 430 OC wi l l cause all or part of the p- phase to dissolve, and it might be expected that subsequent quenching and aging would induce signifcant precipitation hardening. However, aging results in transfmation of the supersaturated solid solution directly to a coarsely dispersed, equilibrium precipitate p-phase without the appearance of Guinier-Preston (GP) mnes or intermediate precipitates (Ref 14) pig. 2). Moreover, the p-phase may form by discontinu- ous precipitation in which even comer cells spread out from grain boundaries. Because the response to aging is relatively poor, alloys based on the Mg-A1 system are genetally used in the as-cast condition,

Themost widelyusedalloy isAZ91C (Mg-9A1-0.7Zn-0.2Mn) inthe form of die castings. As mentioned above, the corrosion resistance of this alloy is adversely affected by the presence of cathodic impurities such as iron and nickel, and for some purposes strict limits have now been placed on these elements. Higher-purity versions such as AZ91 D (0.004% max Fe, 0.001% max Ni, 0.015% max Cu, 0.17% min Mn) have corrosion rates in salt fog tests that are as much as 100 times lower than those for AZ91C, so that they become comparable with those for aluminum casting alloys (Ref 15). Other commonly used alloys of the sametypeareAZ81 andAZ63.

Requirements for specific property improvements have stimulated the development of alternative die casting alloys. For applications where greater ductility and fracave toughness are required, a series of high-purity alloys with reduced aluminum contents is available. Examples are AM60, AM50, and AM20 (Table 2). The improved properties arise because of a reduction in the amount of Mg17A112 around grain boundaries (Ref 16,17). Such alloys are used for automotive parts such as wheels, seat frames, and steering wheels.

The mechanical properties of the AZ and AM series of alloys decrease rapidly at temperatures above 120 to 130 "C (250 to 265 OF) (Ref 18 and 19). This behavior is attributed to the fact that magnesium alloys undergo creep mainly by grain-boundary sliding. The phase Mg17A112, which has a melting point of approximately 460 "C (860 OF) and is com- paratively soft at lower temperatures, does not serve to pin boundaries. Accordingly, commercial requirements have led to the investigation of other alloys based on the Mg-A1 system.

The addition of 1% Ca improves creep strength of Mg-A1 alloys but makes them prone to hot cracking (Ref 17). Creep properties are also improved by lowering the aluminum content and introducing silicon (Ref 18,19). ThishastheeffectofreducingtheamountofMg17A112and,fot die castings that cool relatively quickly, silicon combines with magnesium to form fine and relatively hard particles of the compound MgzSi in grain boundaries (Ref 17, 19). ?ivo examples are the alloys AS41 (Mg-4.5Al-lSi-0.3Mn) and AS21 (Mg-2.2Al-lSi-O,3Mn), both of which have creep properties superior to those of AZ91 at temperatures above 130 "12 (265 OF). Alloy AS21, with the lower content of alumi-

num, performs bet#r than AS41 but is more difficult to cast because of reduced fluidity. These alloys were exploited on alrtrge scale in the various generations of the famous Volkswagon Beetle engine. The creep properties of Mg-Al-Si alloys still fall well below those of competing die cast aluminum alloys such as A380 Fig, 3). and attention has nwntly been directed at Mg-Al alloys containing rare earth (RE) elemmts added as naturally occurring cerium mischmetal (commonly 55Ce-20La- 15Nd-5R) (Ref 17,20). Again, the alloys an suitable only for die castings because slower cooling results in the formation of coarse particles of A12RE compounds. One composition, AE42 (Mg4Al-2RE4.3hh). has a good combination of properties, including creep strength superior to that ofMg-Al-Si alloys (Fig. 3). The mechanism by which creep properties are influenced by RE additions is unclearl although finely dispersed precipitates have been detected in aged binary Mg-l.3RE alloy (Ref 21). In addition, nucleation of a stable Mg$e in grain boundaries has been observed during creep and is considered to reduce deformation by grain-boundary sliding (Ref 1). It should be noted, however, that use of mischmetal does raise the cost of the alloy because this addition is several times more expensive than an equal weight of silicon.

Alloys Based on the Mg-Zn System. Binary Mg-Zn alloys also m spond to age hardening (Ref 22) and, unlike Mg-A1 alloys, form coherent GP zones and semicoherent intamediate precipitates Fig. 2). How- ever, these alloys m difficult to grain refine and are susceptible to microporosity, so they are not used for commercial castings.

Recent work (Ref 23) has shown that atemary addition of copper results in a marked increase in both ductility and response to age hardening (Ref 24). Moreover, mechanical propetties are similar to those of AZ91 at room temperature, but these properties are more reproducible and elevated-temperature stability is increased. One typical sand casting alloy is ZC63 (MgdZn-3Cu4.5Mn). The progressive addition of copper to Mg-Zn alloys has been found to raise the eutectic temperature, which is important because it permits the use of higher solution treatment temperatures, thereby maximizing solutionof zinc andcopper. The structure of the eutectic is also changed from being completely divorced in binary Mg-Zn alloys, with the Mg-Zn compound distributed around grain boundaries and between dendrite ms, to truly lamellar in the tanary copperi-containing alloy (Fig. 4). A typical heat treatment cycle involves solution treatment at 440 "C, hot water quench, and age 16 to 24 hat 180 to 200 "C, Hardening is associated with two main precipitates, (rods) and (plates or discs), which appear to be similar to the phases ob- swved in aged Mg-Zn alloys (Fig. 2). However, the concentration of at least one of these precipitates is greater when copper is pnsent Typical mom-temperature properties are 0.2% yield strength of 150 MPa, UTS of 235 MPa, and elongation of 5%. Although the presence of copper in Mg-Al-Zn alloys has a very detrimental effect on corrosion resistance, this does not sewn to be the case with Mg-Zn-Cu alloys, presumably because much of the copper is incorporatbd in the eutectic phase Mg(Cu, Zn), (Ref 24). Castings made from these alloys are being promoted for use in motor car engines.

Zirconium-Containing Casting Alloys The maximum solubility of zirconium in molten magnesium is

0.6%, and the addition of other elements has been necessary because binary Mg-Zr alloys are not sufficiently strong for commercial applications. These elements have been selected on the basis of compatibility with zirconium, founding characteristics, and desired properties. In this latter regard, the two principal objectives have been improved tensile properties (including higher ratios of yield strength to tensile strength) and increased creep resistance. These requirements have been dictated by the aerospace industries. Nominal compositions of commercial alloys are included in Table 2.

Mg-Zn-Zr Alloys. The ability to grain refine Mg-Zn alloys with zirconium led to the introduction of ternary alloys such as ZK51 (Mg- 4.5Zn-0.7Zr). However, because these alloys are also susceptible to microporosity and are not weldable, they have found little practical application.

TBble 2 Nominal composition, typkal tensile pmpertbs, and charactewhtics of selected magnesium castlng alloys

N o m i d ~ p o s i t i o n ~ld*pl'opeltks ASTM British RE RE a2%yicld Ultiaurtmsllc Ehnlptian, designation designation Al Zn Mu SI Cu Zr (MM) @Id) Th Y & C w d l t h s t ~ ~ ~ g d ~ , M p . dtmgtb,Mp. % Az63 ...

AZ8 I A8

AZ9 I A2.9 I

AM50 ... AM20 ... AS4 I ... AS2 1 ... Z W 1 ZSZ ZK6 I ... ZEAI w u363 ZC63

F a 3 ZREI

HK31 m

m2 ZTI QE22 MSR QH21 QH2 I

WE54 WE54

WE13 WE43

6 3

8 0.5

9.5 0.5

5 ...

4 ... 2 ... ... 4.5 ... 6 ._. 4.2

.._ 6

... 2.7

7 - ...

. . . . . .

... 2.2

. . . . . .

. . . . . .

. . . . . .

. . . . . .

0.3

0.3

0.3

0.3 0.5 0.3 0.4 ... ... ...

0.5

...

...

...

...

...

...

...

...

...

...

...

... 1 I ... ... ...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

... 3

...

...

...

...

...

...

...

...

...

...

...

...

...

... 0.7 0.7 0.7

...

0.7

a7

0.7 0.7 0.7

05

0.5

...

...

...

...

...

...

...

... *..

13

... 32

...

...

...

...

...

...

...

..-

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

... 3.2

... 3 2 ... 25 ... ... 1 1

... 3.25 ...

... 3.25 ...

...

...

...

...

.._

...

...

... _.. ...

_..

...

...

...

...

.._

5.1

4

...

...

_..

...

...

...

...

...

...

...

...

...

._.

... 25 2 5

...

...

As-sandcastT6

An-sanduutT4

Ar-randC%t T4 T6 Asehill cast T4 T6 As-dieeast Ardiecprt Asdieeast As4icCa.u TS T5 T5

T6

sandc.IIT5

CbiUcastT5 spodcruT6

Sand acbill cast T5 SaudochiU AS-undlXlT6

T6

T6

75 110 80 80 95 80

I 2 0 1 0 80

120 125 1 0 s 135 110 140 175 135

145

9s

IM) 90

90 185 185

200

190

180 230 140 220 135 230 200 170 215 215 zoo 135 225 170 235

180

240

140

155 185

185 240 240

2E5

250

ns

4 3 3 5 2 4 3 2 5 2 7*

IIT 4-50 4. 5 5 2

5

3

3 4

4 2 2

4

7

122 I Magnesium Alloys Fatigue Data

Temperature, O F 200 300 400 500 800

2001. I

t

80 1 0 0 1 4 0 1 8 0 2 2 0 2 6 0 3 0 0 3 4 0 Temperature, %

Flg. 3 Seess for 0.1% creep strain in 100 h for cast alloys based on the Mg-A1 syatem and for the aluminum casting alloy A380. Source: Ref 17

Mg-RE Alloys. Magnesium forms solid solutions with a number of RE elements, and the magnesium-rich regions of the respective binary systems all show simple eutcctics. The same applies for alloys with additions of the relatively c h e a p rnischmctals based on cerium or neodymium (e.g., 8ONd-16R-20d) (Ref 1). As a consequence, the alloys have good casting charactaistics, because the presence of the relatively low-

eukctics as networks in grain boundaties tendg to suppress ity. In the as-cast condition, the alloys generally have cored a-

grains surrounded by @-boundary networks. Aging causes precipitation to occur within the +s (Ref 21), and as mentioned above, the generally good creep resistance they display is attributed to both the strengthening effect of this precipitate and the presence of the grain- boundary phases that reduce +-boundary sliding (Ref 1).

The properties of Mg-RE alloys are enhanced by adding zirconium to refine grain size, and further increases in strength occur if zinc is added as well. The most widely used of thae alloysis ZE41 (Mg-4.2Zn- 1.3Ce-O,aZr), whichhasmoderatestrength whengivenaT5agingaat-

b F‘ig. 4 Effect of the addition of copper on the morphology of the eutectic for alloy Mg-6Zn. (a) Binary alloy solution treated 8 h at 330 “c. 1OOx. (b) Ternary alloy Mg-6Zn-l.SCu, solution treated 8 hat 430 “C, 100%

mcnt that is maintained up to 150 “C (300 ”p). One popu has been helicoptatrarrsmission housings (Ref 25). Higher

at temperatures up to OY EZ33 (Mg-3RE-2.5Zh-

strength might be expected with ve gtain-boundary phase contain-

ing Zinc and RE elements is formed that both causes embrittlement and lowers the solidus temperature, themby ieduciag the opportunity to 80- lution treat the alloys prior to aging. Fisher (Ref 26) has shown that this latter phase can be dissockd by a specialized treatment involving prolonged heating in a hydrogen atmosphere, and this tfCatment has been successfully applied to &-wall castings made from the alloy ZE63

Onerecent development haa sought to take advantageof theparticu- lady high solid solubility of yttrium in magnesium (maximum of 1 wt%) and the capacity of Mg-Y alloys to age harden. A series of Mg Nd-Zr alloys has been produced combining high strength at ambient

at temperatum up to 300 o c e, the heat-treated alloys have that of other

magnesium alloys and comparable to that of many alu al viewpoint, pun yttrium is

megnesium because of its high melting point (1500 “C) and its strong affinity for oxygea It has been found that a cheaper ythiwn-containing mischmetal containing around 75% of this element, together with heavy RE metals such as gadolinium and erbium, can be substituted for pun yttrium (Ref IS). Melting prsc- tices have also becn changed so that the alloys can be processed in an inert atmosphere of argon and SF6

Precipitation in Mg-Y-Nd alloys is also complex (Fig. 2). Extremely h e p”-plates having the DO19 structure are formed upon aging below 200 “C (390 OF). However, the T6 treatmmt normally involves adng at 250 O C (480 “p), which i s above the solvus for and leads to precipitation of fine plates of the bodycentered orthorhombic phase p, which is thought to have the composition MglzNdY (Ref 24). Maximum strengthenhg combined with an adequate level of ductility have been found to OCCUT in an alloy containing approximately 6% Y and 2% Nd. The f h t commercially available alloy was WE54 (Mg-5.25Y- 3.5RE(1.5-2Nd)-0.45Zr) (Ref 23). condition, typical tensile properties at room temperature are 0 strength of 200 MPa, UTS of 275 MPa, and elongation of 4% wed elevated-tcmpmture properties superior to thoseof existing magnesium alloys (Figa 5). It was revealed, however, that prolonged exposure to temperatures around 150 O C led to a gradual reduction in ductility to levels that were unacceptable (Ref 15). and this change was found to arise from the slow secondary precipitation of the j3”-phase throughout the grains (Ref 24). Sub- sequently, King et d, (Ref 25.28) showed that adequate ductility can be

(Mg-5.3Zn-2.5RE-O.7Zr).

1 10 loo loo0 loo00 Exposu~, h

Np, 5 Effect of exposure at 250 “C on 02% yield slrength at loom temperature for several w t magnesium alloys containing rare earth elements

Magnesium Alloys Fatlgue and Fractun I123

retained with only a slight reduction in overall strength if the yttrium content is reduced and the neodymium content is increased. On the basis of this work, an alternative composition WE43 (Mg-4Y-2.25Nd-1 Heavy RE-0.4 min Zr) was developed (Fig. 5). (The principal heavy RE elements are ytterbium, erbium, dysprosium, and gadolinium,)

Alloys Based 011 the Mg-Tb System. The addition of thorium also increases creep resistance in magnesium alloys, and cast and wrought alloys have been used in Service at temperatures up to 350 OC (660 "F). As with the RE elements, thorium improves casting properties and the alloys an weldable (Ref l).

Mary compositions such as HK31 (Mg-3Th-OP7Zr) have been available for some time and have microstructures similar to those of the Mg-RE-Zr alloys. Precipitation hardening again leads to the formation of an ordered DO19 phase, which is probably Mg3Th or Mg23Th6 (Fig 2). The good creep resistance is attributed to the presence of fine dispersions of a phase such as this within the @ns, together with another thoriumcontaining phase that forms discontinuously in grainboundaries. Again in parallel with other alloys based on the Mg-RE system, thoriumcontaining alloys have been developed to which zinc has been added, such as

presence of zinc further increases creep smgth (Fig. 5). and this is attributed, at least in part, to the introduction of an acicular phase that forms along grain boundaries. However, little appears to be known about the precise influence of zinc on precipitation in the Mg-Th system.

Although thorium-containing alloys have found applications in missiles and spacectaft (Ref 28), they are now losing favor because of environmental considerations and arc generally considered to be obsolete. In Britain, for example, alloys containing BS little as 2% of this element are classified as radioactive materials that require special handling, thereby incnasing the cost and complexity of manufacture.

Alloys Baaed on the Mg-Ag System. The potential importance of the Mg-Ag system was recognized by Payne and Bailey (Ref 30), who d imvend that the relatively low tensile propedes of Mg-RE-Zr alloys couldbe much increased by the addition of silver. Substituting neodymium mischmetal for cerium mischmetal gave a further increase in sangth, and several compositions have been developed for service at elevated temperatures.

The most widely used alloy has been QE 22 (Mg-2.5Ag-2REINdl- 0.7Zr), for which theoptimal heat treatment is solution treatment for4 to 8 h at 525 'C (980 "p), cold water quench, and aging 8 to 16 h at 200 "C (390 OF). Tbis alloy has been used for a number of aerospace applications, including landing wheels, gearbox housings, and rotor heads for helicopters (Ref 15). If the silver content is below 2%. the precipitation process appears to be similar to that occurring in Mg-RE alloys and involves formation of Mg-Nd precipitates (Ref 24). Howevtr, for higher amounts of silver, two independent precipitation processes have been reported, both of which lead ultimately to the formation of an equilibrium phase of probable composition Mgl2NdzAg (Pig. 2). The presence of a phase withtheD01~shvcture hasnotbeenconfirmed,althoughonepre- cipitate, designated y, has characteristics that suggest it may be such a phase.. Precipitate size is also refined by the addition of silver, and maximum age hardening and cteep resistance appear to be associated with the presence of the y+ p precipitates.

Elevated-temperature properties may be further enhanced by the partial substilution of the RE (Nd) component by thorium. One alloy, QH2l (Mg-2.SAg-lrh-lREINd]-O.7Zr), showed the highest values of tensile prqraties and creep resistance at temperatures up to 250 "C (480 OF), prior to the development of the alloys containing yttrium. However, it will be recalled that these latter alloys have the advantage of high oomsion re sistance, which is not shared by alloys such as QE22 or QH2l due to the presence of the noble metal silver. Moreover, QH2l is also becoming obsolete because of the presence of the radioactive element thorium

HZ32 (Mg-3Th-2.2ZnO.7Zr), and ZH62 ([email protected]), ThC

'

Production of Castings Most magnesium alloy components are produced by high-pressure

die casting. Cold-chamber machines are used for the largest castings,

and molten shot weights of 10 kg or more can now be injected in less than 100 ms at pressures that may be as high as 1500 bars (Ref 31.32). Hot-chamber machines are used for most applications and are more competitive for smaller sizes because shorter cycle times are obtainable. Magnesium alloys offer particular advantages for both thew processes (Ref 33,34):

Most alloys show high fluidity, which allowe casting ofin- tricate and thin-wall parts (e.g., 2 mm). Magnesium has a low specific heat per unit volume when compared with other metals. For example, comparative ratios for magnesium, aluminum, and zinc are 1 to 1.36 to 1.63. This meam that magnesium caetings cool more quickly, allowing fseter cycle times and reducing die wear.

o Highgatepressurescanbeachievsdatmoderatepreeeures because of the low density of magnesium. Iron &om the dies has very low solubility in magnesium alloys, which is beneficial because it reduces any tendency to sticking.

Magnesium alloy components can be successfully prepared by sand casting and by gravity casting into permanent molds. However, conventional pouring practices can cause problems, as turbulent metal flow may introduce oxides and dross because of thereactive nature of magnesium. One solution has been to introduce the molten metal into the bottom of the mold cavity, thereby allowing unidirectional filling of the mold, and to apply mnmlled pressure to improve metal flow (Ref 25, 33). Such a process has been adapted for the production of automotive wheels (Ref 33, 35). Squeeze casting has also been used to prepare higher-quality castings from existing alloys such as A291 (Ref 17) and to ptoduce castings in alloys that could not be successfully cast by con. ventional processes. One example (Ref 36) is the alloy Mg-12Zn-lCu- lSi, which exhibits good room-temperature properties (e.g., 0.2% yield strength of 200 MPa) that arc sustained at relatively high levels through thetemperaturerange l00to2OO"C (212to390"F).

Magnesium alloys are also amenable to thixotropic casting, which offers the opportunity to produce goodquality fine-grain products more cheaply than by high-pressure die casting (Ref 17). One promising technique involves heating alloy granules to approximately 20 'C (36°F) below the liquidus temperature and injection molding the resulting slurry into a die by mans of a high-torque screw drive. Tests with the alloy AZ91 have shownthat althoughtensilepropertiesanlittlechanged,impact toughness is significantly improved (Ref 37).

*

0

Mechanlcal Properties 'Qpical mechanical properties of various cast and wrought magne-

sium alloys are listed in Table 3 (Ref 38). More thorough compilations of typical mechanical properties are in Ref6 and in Volume 2 of the ASM Handbook, Properties and Selection: Nonfewus Alloys and Special- Purpose Materials,

Forcastings, these values may be obtained by teeting separately cast specimens. Tensile strengths of investment mold and shell mold castings compare favorably with those of sand and pamanent mold castings, Xeld strength, tensile strength, and petcentage elongation may vary with cooling rate and generally are lower than those of separately cast sand mold test bars. Likewise, tensile properties will vary from specimens machined from different sections of castings of varying thickness. Some specifications permit a 25% reduction in tensile strength and a 75% reduction in elongation for specimens machined h m castings, as compared with requirements for separately cast bars. Minimum tensile properties are shown in Wles 4 and 5.

Fatigue strpngth of magnesium casting alloys, as dewmined using laboratory test samples, covers a relatively wide scatter band, which is characteristic of other metals as well. The stress-life (S-N) curves have a gradual change in slope and become essentially parallel to the horizontal axis Ft 10 to 100 million cycles (pig. 6) (Ref 39). Most of the fatigue data

124 I Magnesium Alloys Fatigue Data

Tabk 3 Representative mechanical properha of magnrrium alloys

Rotatian beam htinue, MPI CReP stmrth, m Teaslle strrnpth at Stmbr03'k TE 8tmalafillhmet

25 OC, MPS in 100 h Indknted C Y C k Allw Zkroer I E YS CYS UTS 95oc 200% 250T 105 106 107 5 x 10'

AZ92A

EQZlA QE22A W 4 A ZE41A Ms 1A

AMm AS41A AZ91AorD ExtrusbioM AZ31B AZBOA HM3lA zK3oA W6oA ZM21A sheet AZ3lB

W l A ZROA W I A

DkUlSbg8

F T4 T6 F

T4 TS T6 T6 T6 T6 T5 T5

F F F

F T5 T5 F TS F

0 H24 T8

0 .,,

2 14 5 2 9 2 2 4 4 4 5 8

8 6 3

15 7

10 18 12 11

21 15 I 1 8

13

95 85

130 9s 95

110 145 195 205 2MJ 140 165

130 140 160

m 275 270 239 295 162

150 220 160 185 I3 I

95 85

275 95 95

110 145 195 205 100 140 165

130 140 160

95 240 160 213 21s ,,.

I10 180 130 154 ...

165 275

165 275 180 275 26 I 275 275 205 275

220 210 230

260 380 UH 309 360 255

.,.

255 290 250 270 232

... ,,. ,,. ,,. ,,. ... 55 .., ,,. ,,, ... 65

... ,,. .,.

so ,,, ... ... 20 ...

55 30 , I .

...

...

,,. 110 . I , I35 . I , 125 ( I , 115 ,,. 125 1 1 1 125 ... 130 36 ... 30 150 56 .,. I , , 124 ,,. 105

... ... ,., 110 .., .,.

.I, 180

.,. 190 70 125 ,I, 152 ... 210 ... ...

... ...

105 11s 105 105 110 110 115 100 125 102 97 75

... 90 ,,.

160 175 105 131 170 ...

. . a

12o(b) ... ... ...

95 105 90 95

105 105 100 98

115 99 96 70

... 90 ...

145 I#) 90

124 150 ...

,,. 103(b) .,. ... . . a

90 100 85 92

100 I[n 97 96

105 97 94 75

... ... ,..

140 I55 90

124 145

( . I

10;;a) ... ... ...

Note: %E, pereent elongation;YS, yield strength; CYS, cornpmive yield strength; UTS, ultimata tensile strength; TE, total elongation. (a) CIWP &.meion only, (b) Can- tilever bending fatigue withR = -1. (0 ) 150 "C. Souroe: Ref28

n b l e 4 Minimum tensile Drowrties from drrianeted arms of sand c w t i n m

C h 1 C h 2 C b u 3 Alby Pmwr %E YS,MPs(MI Ul%MPs(lub %E YS,MpI(lui) UTS,MPa(bl) %E YS.hlPa(h0 vT$ m (kni) AMlOOA T6 3 140 W) 260 (38) 1.5 125 (18) 240(35) 1 110(16) 205 (30) Az91c T6 4 125 (18) 240 (35) 3 I10 (16) ux) (29) 2 95 (14) 185 (n) m92A T6 3 170(2S) 275 (40) 1 140 (20) 235 04) 0.75 125(18) 205 (30)

255 (371 4 IM(23) 230 (33) 180 (26) 2 165(24) 255 (37)

2 130(19) 215(31)

QE22A T6 4 195 (28) 275 (40) 2 290 (42) 5

I60 (23) 3 145 (21) 235 (34) 4 130(19) 220(32) 3 llS(17) m(29)

195(28) 260(38) ZE63A T6 6 M62A n 5 PCTlA T5 6 145(21) 250 (36) ZK61A T6 6 ~JN (29) 290 (42) 4 180 (26) 25s (37) 2 lfQ(23) 235 (34)

Note: %E, percent elongation; W, yield strength, W, ultimate tensile strength. Source: MILM48062B, 'Magneuium Alloy Caethga-High S h n g W

HK3lA T6 6 llO(16) 230 (33) 3 95 (14) 100 (29) I 85(12) i m ( w

l8OW) 275 (40)

formagnesiumalloys ares-Ncurvesdating from the 1930s to the 1%Os. A substantial portion of the early S-Ndata was summarized by H.J. Gro- ver et al, (see Table 6) (Ref 40). The effcct of different surface conditions is shown in Fig. 7.

The effect of temperature on fatigue limits is shown in Fig. 8 for alloys developed for high-temperature service, such as E233, HZ32, and REPl4. The fatigue limit of QE22A is also shown. The reduction in fatigue appears to be much less for QE22A at high temperatures.

The hexagonal crystal structure of magnesium places limitations on the amount of deformation that can be tolerated, particularly at low tern- peratuns. At mom temperature, deform_ation occurs mainly by slip on the basal planes in the close-packed < I 120> directions and by twinning

on the pyramidal { 1072) planes. With stresses paratlel to the basal planes, twinning of this type is only possible in compression, whereas with stresses perpendicular to the basal planes, it is only possiblein tension. Above about 250 "C (480 OF), additional pyramidal { 101 1 ) slip

Magnesium Alloy8 Fatigue and Fracture / 125

Table I Mechanical propertlea of permanent mold castings

AMlOOA

AZ63A

AZ81A m1c

EZ33A

HK31A

m2A

QmU

F T4 T6

T61 F

T4 T5 T6 T4 P

T4 T5 T6 F

T4 TS T6 n T6

TS

T6

25 25 25 25 25 25 2.5 25 25 25 25 25 25 25 29 25 25 25

260 25

260 2s

260 25

315

,.. 70 6 70 2 105 I,. 115 4 75 7 75 2 85 3 110 7 75 .,. 75 7 75 2 85 3 110 ... 75 6 75 ... 85 ... 125 2 95

. I . 55 4 90 I,. 90 4 Po

I . , 55 2 170 ... 70

10 10 15 17 I 1 11 12 16 I I 11 11 12 16 I 1 1 1 12 18 14 8

13 13 13 8

25 10

140 235 23s 235 180 235

235 235 160 235 160 235 160 235 160 235 140 90 I83 149 185 90

240 90

i m

20 34 34 34 26 34 26 34 34 23 34 23

n 21 27 13 35 13

. I , .,. 1.5 m ... 95 .I, 95 ( I . ...

2 m I,. I . .

0.8 95 1.8 m .., ... 1.8 m 0.8 100 ... a . .

. I . ... 2.5 m ... I . .

..I 110 0.5 85 ..I 40 1 .o 80

1 .o 80 ... 40 0.5 160 .I, 55

.., m

.,. 10 14 14

10 I , .

, I .

14 10 ... 10

14 ... ... 10 ... 16 12 6

12 10 12 6

23 8

N m %E, peroent elongaUrm,YS, yield e t r e ~ rrrS, ultimata tan& etrength. Source: ASRd BlB9 and federal speeification BB.M-5M:

.., 175 175 175

I75 .,.

... 175 175 ... 175

175 ... ... 175

I , .

175 105

160 95 IM)

220 70

m

m

. . I

25 25 23

25 ... 4. .

2s 25 ... 25

25

25

25 15 10 23 14 23 10 32 10

...

...

...

planes become operative so that deformation becomes much easier and twinning is less important. Production of wrought magnesium alloy products, therefore, is normally carried out by hot working.

Wrought materials are produced mainly by extrusion, rolling, and press forging at tempvaturns in the range 300 to 500 OC (570 to 930 OF), and detailed accounts of deformation and fracture behavior are available (Ref 1,3,4). Two general comments can be made concerning directionality effects in wrought products:

Because the elastic modulus does not show much variation in different directions ofthe hexagonal magneaium crystal, p d d orientation has relatively little && on the modulus ofwmught products. Because twinning readily occut~ when compressive streams are parallel to the basal plane, wmught magnesium alloys tend to show lower values of longitudinal yield strength in compression than in tension. The ratio may lie between 0.5 and 0.7 and is an important characteristic of

175 5

104 Id 1Oa 1 o7 IOa 1 09 cycrea

Ng. 6 Fatigue svengm ofmagnesium alloys airaorn temperature. Source: Ref 39

magnesium alloye because the design of lightweight &uc- tures involves buckling properties, which in turn are strongly dependent on compressive strength. The value varies wi th different alloys and is increased by promoting finegrainaieebecausethecontributionofgrainboundariee to overall strength becomes proportionately greater.

As with cast alloys, the wrought alloys may be divided into two groups according to whether or not they contain zirconium (Wile 7). Specific alloys have been developed that are suitable for wrought products, most of which fall into the s a m categories as the casting alloys al- ready discussed (Ref 2,6). Examples of sheet and plate alloys include A231 (Mg-3Al-IZn-0.3Mn), which is the most widely used because it offers a good combination of strength, ductility, and cornsion resistance, and thoriumcontaining alloys such as HM21 (Mg-2Th-0.6Mn), which show good creep resistance to temperatures up to 350 'C. Magne- sium alloys can be easily extruded into either solid or hollow sections at speeds that depend on alloy content. Higher-strength alloys such as AZ8t (Mg-8Al-IZn-0.7Mn), ZK61 (MgdZn-O,7Zr), and the more recent composition ZCM7 1 1 (Mg-6.5Zn-1.25Cu-0.75Mn) all have strength-to-weight ratios comparable to those of the strongest wrought aluminum alloys. ZM2l (Mg-2Zn-IMn) can be extruded at high spesds and is the lowest-cost magnesium extrusion alloy available. Again, thorium-containing alloys such as HM31 (Mg-STh-IMn) show thebest elevated-temperature properties. Magnesium forgings are less common and arc often preextruded to refine microstructure, and alloy compositions are similar to those used for other wrought products.

One alloy system confined to Specialty wrought components is Mg- Li, which has been exploitedto produce lightweight materials (e.g., specific gravity 1.35) that have particularly highvaluesofspecificmcdulus. Lithium has a high solid solubility in magnesium (Ref 10, l l ) , and bi- nay alloys containing more than l l wt% of this element have the more desirable body-centered cubic structures, thereby offering the prospect of extensive cold formability (Ref41). Such alloys m also amenable to age hardening, although they overage and soften at relatively low temperatures (e.g., 50 to 70 "C) as a consquence of the abnormally high mobility of lithium atoms and vacancies. Somewhat p t e ~ stability has been achieved by adding other elements, such as aluminum (e.g.,

\

Table 6 Cast magnesium alloy fatlgue strength i5

5

911 3 F ~ S h J l g t h ( ~ ~

un, ys, Fatigoelomling Fatigue sped men ksi) at iadated fyf*s (D

Material Deslpation Condition ksi lrJi %E .&pe condition 'I).pe Siz%h. K, ltf ld 1$ 10' Id Comments 0 Snnd castings and permanent mold casting alloys AZ63-AC AZ63A-F AZ63-AC AZ63A-F

AZ63-AC AZ63A-F

AZ63-ACS AZ63A-T2 AZ63-ACS AZ63A-T2

AZ63-ACS AZ63A-T2 A7.63-ACS AZ63A-T2 AZ63-ACS AZ63A-T2 AZ63-HT AZ63A-T4 AZ63-m AZ63A-T4

AZ63-HT AZ63A-T4

AZ63-HT AZ63A-T4 AZ63-HT AZ63A-T4 AZ63-HTA AZ63A-T6 AZ63-HTA AZ63A-T6

AZ63-HTA AZ63A-T6

AZ63-HTA AZ63A-T6 AZ63-HTA AZ63A-T6 AZ63-HIA AZ63A-T6

AZ63-HTA AZ63A-T6 AZ63-HTA AZ63A-T6 AZ63-HTA AZ63A-T6

AZ63-HTS AZb3A-TI AZ63-HTS AZ63A-TI

AZ63-HTS AZ63A-TI

AZ63-HTS AZ63A-TI AZ63-HTS AZ63A-TI AZ63-HTS AZ63A-TI AZ63-HT.S AZ63A-TI

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

29.0 29.0

29.0

29.0 29.0

29.0 29.5 28.0 40.0 40.0

40.0

39.0 29.0 40.0 40.0

40.0

42.0 33.5 33.5

25.0 24.5 24.5

39.0 39.0

39.0

38.3 38.0 ... ...

14.0 14.0

14.0

14.0 14.0

17.7 16.7 13.7 14.0 14.0

14.0

15.0 12.0 19.0 19.0

19.0

19.0 165 165

15.0 15.0 15.0

18.0 18.0

18.0

17.0 16.5 ... ...

6.0 6.0

6.0

5.0 5.0

5.0 6.0 9.0

12.0 12.0

12.0

11.0 15.0 5.0 5.0

5.0

7.7 13.0 13.0

15.0 15.0 15.0

8.0 8.0

8.0

11.0 15.0 ... ...

RB RB

RB

RB RB

RB RB RB RB RB

RB

RB RB RB RB

RB

RB RB RB

RB RB RB

RB RB

RB

RB RB RB RB

-lR -1 R

-1 R

-1 R -1 R

-1R -I R -I R -1 R -lR

-1 R

-1 R -1 R -1 R -1 R

-1 R

-I R -I R -1R

-1R -1R -lR

-1R -lR

-lR

-1R -lR -lR -I R

UMOtChd 0.m C i n o t c h 0.0295r.

0.29% 03540

0 . m . om, 0.480

urmached om CircularnMch 0.0295,

0.295d. 03540

unnotdwd om Umched 0.m unnotdwd 0.m unnaehed 0.m Cinotch 0.0295.

0.2954 03540

0 . m . om. 0.480

Unnotched 0.W Unnotched 0.W Umched 0.m Circularnotch 0.0295.

O B . 0.3540

O M n , 0.m. 0.480

Unnotched 0.W

circularnotch 0.0295r. 0.29% 03540

Vnotch Wnach,

b o t c h WnMfh.

Vnotch 60" notch.

UMOtChd

UMotched 0.m UMOIChd 030d C i n M c h 0.0295r.

02956 0.3540

C i n o t c h 0.0295r. O B . 03540

W m h

0.m. 0.4m

UMOtChd 0.m

vnotch 0 . m .

UnMnChed om

unnotdwd 0.m circularnotch 0.0295r,

02956 03540

urnached am

... 2

5

... 2

...

...

... 2

5

...

...

... 2

5

...

... 2

...

... 2

... 2

5

...

...

... 2

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

18.0 13.5

8.5

23.0 125

23.0 ... ... 21.5 17.5

8.5

...

... 18.0 11s

85

... 172 I15

...

... 95

21.0 14.0

75

... 17.5 17.4 12.2

...

...

...

...

...

... 18.5 10.9 ... ...

...

19.1 11.9 ... ...

...

16.8 ... ...

11.6 ... ...

...

...

...

18.0 14.0 ... ...

10.5 7.0

5.0

15.0 9.5

15.0 14.6 95

165 9.0

7.0

18.3 10.7 16.0 9.5

5.0

16.0 12.5 7.0

9.2 9.0 6.0

16.0 105

6.0

16.0 125 123 7.8

105 7.0

4.0

12.0 8.5

12.0 12.0 8.4

16.5 8.5

6.5

17.5 9.5

15.0 9.0

3.5

15.0 11.0 7.0

7.4 7 5 5.0

15.0 9.5

5.5

15.0 120 12.3 7.0

...

...

...

...

...

... Alldataat150°F AUdataat2750F

...

...

...

Fatiguedataat 150°F Fatigue data at 275 "F

...

...

...

Fatigue data at 150 "F Fatigue data at 250°F AU dataat 250°F

Fa~igue data at 275 "F All data at 300°F AUdataat300T

...

...

...

Fatiguedataat150°F All dataat 200°F Fatigue data at 200 "F Fatigue data at 200 "F

~ ~~

(continued)

Table 6 Cast manneslum alloy fatigue strength (conthusd)

AZ63-HTS AZ63A-Tl AZ63-HTS AZ63A-T7 AZb3-HTS AZ63A-TI AZ63-HTS AZ63A-T7 AZ63-HTS AZ63A-TI AZ92-AC AZ92A-F AZ92-AC AZ92A-F

AZW-AC AZ92A-F

AZ92-ACS AZ92A-T2 AZ92-ACS AZY2A-n AZ92-Err AZ92A-T4 AZ92-Err AZ92A-I-4

AZ92-HT AZ92A-T4

Az92HT AZ92&-T4 AZ92-HT AZ92A-T4 AZ92-WL4 AZ92A-T6 AZ92-WA AZ92A-T6

AZ92-HTA AZ92A-T6

AZW-HIh AZ92A-T6 AZ92-HTA AZ92A-T6 AZ92-HTA AZ92A-T6

AZ92-HTA AZ92A-T6 AZ92-H1;4 AZ92A-l5 AZ92-H'lA AZ92A-T6

AZ92-HTS AZ92A-I7 Az92-Errs AZ92t-m

AZ92-HIs AZ92A-TI

Az92-m AZ92A-TI

...

...

...

0.20in. thick 0.20 in. thick 0.20 in thick 0.20 in. thick 0.20 in. thick

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

. I .

...

...

...

...

...

...

...

30.3 27.0 27.0

39.0 38.0 27.0 18.0 7.5

24.0 24.0

24.0

25.0 23.8 40.0 40.0

40.0

38.5 31.0 40.0 40.0

40.0

42.0 35.0 35.0

28.0 28.0 28.0

40.7 40.7

40.0

27.5

I52 14.3 143

18.0 165 143 11.5 4.0 14.0 14.0

14.0

19.0 145 16.0 16.0

16.0

19.0 17.0 23.0 23.0

23.0

260 20.5 M5

18.0 18.0 18.0

220 22.0

20.0

155

18.0 26D 26.0

8.0 15.0 26.0 40.0 77.0 2.0 20

20

8.0 3.0

10.0 10.0

10.0

7.7 30.0 20 20

2.0

2.0 31D 31D

38.0 35.0 35.0

411 41)

3.0

23.0

RB RB RB

B B B B B RB RB

RB

RB RB RB RB

RB

RB RB RB RB

RB

RB RB RB

RB RB RB

RB RB

RB

RB

-IR -lR - l R

-1R -lR -lR -1 R -1 R -1R -I R

-lR

-I R -1 R - l R - lR

- lR

-1 R -1 R -I R -1 R

-IR

-1R - lR -I n

-1R -lR -1R

-IR -lR

-lR

- lR

.._

... 2

.._

...

...

...

...

.._ 2

5

...

...

._. 2

5

...

...

... 2

5

_.. _.. 2

_.. -.. 2

... 2

5

1..

.-.

...

...

... _.. _.. ... ... ... ...

...

-.. .-. ._. ...

.._

...

...

...

...

.._

.._

... _..

...

._.

._.

...

...

...

...

... 135 10.0

15.0 13.4 115 11.0 7.3

18.5 11.0

8s

...

... 20.0 15.5

101)

_.. _.. 19.5 14.0

7.5

... 145 135

... 16.0 11.5

20.5 145

8.0

15.5

11.5 11.6 ...

128 10.6 &6 63 5 3 ... ...

...

15.8 8.5 ... ...

...

182 120 ... ._.

.._

17.7 ... ._.

13.4 ... ...

...

...

_..

.._

10.7 95 5.5

11.0 8.6 6.2 5.0 3.0

145 85

5.0

I43 8 2

165 13.5

6.0

17.0 10.8 16.0 9.5

5.0

16.5 11.5 811

12.0 11.0 6.5

15.0 10.0

6.5

10.0

9.6 9.5 5.0

...

...

...

...

... 131) 7.5

4.0

13.5 8.0

16.0 125

5.5

I&O 9.0

15.0 9.5

4.5

15.0 10.5 6.0

10.0 10.0 6.0

131) 9.0

6.0

9.0

Alldaaat275"F All data m 300 O F AUdatam30OoF

..-

...

Fatiguedam at 150°F Fatigue dam a275 OF

...

...

_.. _..

...

Fhgue dam at 150°F AUdataa1250"F AU dataat 250°F

L: 9 B 3 e 6 Y

lbbk 6 Cast magnesium alloy fatigue stmngth (continued)

Az92-rn Azm-m

Az92-KIs Azm-n

EM61-ACS EMIxA-TZ EMLI-ACS EM61XA-TZ EM61-HlA EIu61XA-l% EM61-HlA EM61JCA-T6 EM61-Hu EM61XA-T6 EM61-HlA EM61XA-T6 EM6l-HlA EM61XA-T6 EM61-HlA EM61XA-T6 EM61-HIx EM61XA-T6

A Z ~ - H T S m - n

ElO-HIA EIOXA-T6 ElO-HJA EIOXAT6

ElO-Hu EIOXA-T6 EIO-IFFA EIOXA-16 E M I O I - m EMIOIA-T6 EMIOI-HlX FMIOIA-T6

EMIOI-WU EMIOlA-T6 EMIOI-WUEM101A-l5

Nb3X-AC -A-F AZb3X-AC AZ63A-F AZ63X- =A-12 Acs

ACS AZ63X- MA-TZ

AZ63-HT AZ63A-T4 AZ63-HT AZb3A-T4 Az63-m Az63A-TI

Az63-HW AZ63A-"7 m-HIS mw-n AZb3-HE AZ63A-m m3-m =A-TI AZ63-HTS AZ63A-'I7 AZ63-HTS AZ63A-TI AZ63-m Az63A-T6 AZ63-WU AZ63A-T6

...

...

...

...

.._

...

... 0.20 in thick 0.20 in. thick 0.20 in. thick

...

...

...

...

...

...

0.2OinIhiCk 0.20 in thick

...

...

...

...

...

...

...

.._

...

...

...

...

...

...

...

...

...

...

.-.

27.5

40.0 28.0 18.0 16.0 19.3 19.7 19.3 19.7 ... ... -..

19.0 19.0

19.7 19.7

19.0 16.5 20.0 20.0

20.0 20.0

29.0 29.0 29.0

29.0

40.0 40.0 39.0 40.0 40.0 38.0 303 303 27.0 40.0 40.0

15.5

21.0 17.0 14.0 120 17.7 15.6 17.7 15.6 ... ... ...

...

...

1 6 5 16.5

... 9 s

185 18.5

15.2 15.2

14.0 14.0 14.0

14.0

14.0 14.0 18.0 37.0 17.0 165 15.2 15.2 14.2 19.0 19.0

23.0

1.0 38.0 0.5 1.2 1.2 13 12 13 ... ... ...

...

...

1.0 I 1)

... 7.0 0.8 0.8

05 05

6.0 6.0 5.0

5.0

12.0 12.0 8.0 7.0 7.0

15.0 18.0 18.0 403 5.0 5.0

RB

RB RB RB RB RB RB B B B RB RB

RB RB

RB RB

B B RB RB

RB RB

Ax Ax Ax

Ax

Ax Ax Ax Ax Ax Ax Ax Ax Ax Ax Ax

-I R

-1 R -I R -I R -I R -I R -lR -1 R -1R -IR -I R -1 R

-1 R -1R

-I R -I R

- I R -1 R

-1R -IR

-1R -I R

0.0 R a25R &OR

0.25 R

OBR 0.25 R 0.25 R 0.OR 0 2 5 R 025R O.0R 0.25 R 0.25 R 0.0 R 0.25 R

circularnotch 0.U295r. 0.295d. 0.354D

Ciiamch 0.0295r. 0.29Sd. 0.3.54D

Unncnched 0201 UnDorched 0.201 Unaotehed 0-lad CicularoaEh a029fir.

0.2954 0.3540

unrmcbed a3od Cina~kaach O.oM9r.

O W . 0 3 W

UnOMchd 0.m Unaolched 03od Unnotchal aMd

Unnotched aJod

urmorbed om UrmOcEhed om Unoaehed ... Unnolchcd 030d unnocdwd a3od Uanached ... unwtched a m unwtched om Unnocdwd ... uanadvd om UoDaChcd 030d

2

...

...

...

...

...

...

...

...

...

... 2

... 2

... 2

...

...

... 2

... 2

_.. _.. ... ... ... .-. ._. .-. ... ... ... ... ... ... ...

...

...

...

...

...

...

...

... 14.0 ... ... ...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

110

.-.

...

...

... 11.0 12.5 125 10.0 7.7

11.2 9.6

11.0 9.0

I20 9.0

81) 13.0 10s 10.0

12.0 10.0

220 24.0 23.0

26.0

23.0 25.0 31.0 24.0 29.0 2b.2 21.5 24.0 24.4 28.0 25.0

.-.

17.3 125 8.3 6.8 9.8 9.3 9.5 7.0 5.3 ... ...

...

...

...

...

...

._.

._.

...

...

...

20.0 21.5 21.0

23.0

19.0 225 25.7 21.0 26.0 23.8 #LO 22.0 220 21.0 23.0

5.5

15.0 10.0

5s 7.8 8.0 7.3 7 a 3.0 7.9 6.5

...

...

...

...

...

6.5 4.0 ... ...

...

...

18.0 19.0 19.0

21.0

15.0 21.0 24.0 21.0 24.0 21.5 18.5 m.0 20.0 20.0 21.0

4.5

13.0 9.0 7.0 4. I 6.5 7.5 ... ... ... 6.5 6.5

9.0 5.5

7-5 65

...

... 7.5 5.5

8.0 5.0

_.. ... ...

...

...

...

...

...

...

... ...

...

...

...

...

All dam at 300°F e - 0

higuurdataat 1.50°F yo Fat iguehat IM"F z n All dam Y 275 O F

(YI c AlldPIPaInS "F ...

All data at -m)T

All dataat 300°F Fatigue data a1 600 OF

...

...

...

...

...

Fatigue data at 27s "F AIR data a ns "I:

... All daurafrOO'F

...

All d r p ~ 275 "F All &a P 275 "F

...

...

...

...

...

...

...

...

... AU b a t 200°F MI b a t 2750~ AU -at 275'F MdsaM300"F

...

...

(continued)

Table 6 Cast magnesium alloy fatigue strength (continued)

F.tiradrradlb(auXrtma

AZ63-H?i4 AZ63A-Tb ... AZb3-H'h AZb3A-Tb ... AZ92-HlA AZ92A-T6 ... AZ92-Hu AZ92A-T6 ...

AZ92-HTS AZ92A-TI ... AZ92-HTS AZ92t-TI ... Casting albys (tested with casl skin p-I) AZ63-HIi4 AZ63A-T6 I-beam, canlilever

AZbf-Hlii\ AZ63A-T6 1-bentn.cantilever

AZ63-HlM AZ63A-TI I-beam,canIilever

AZ63-HTAS AZ63A-TI I-beam. cantilever

AZ92-HT AZ92A-T4 Longitudinal.

CM62 EM62A-F I-beam. cantilever

-62 EM62A-F 1-beam, cantilever

CM62 EM62A-F I-beam. cantilever

specimen

specimen

specimen

specimen

0.200 in. thick

specimen

specimen

specimen

Die casting dbp AZ91-ACS AZ91A-T2 AZ91-ACS AZ91A-T2 AZ91-HT AZ91A-T4 AZ91-HT AZ91A-T4 AZ91-m AZ91A-T6 AZ9 I -HE4 AZ91 A-T6 AZ91-HTS AZ91A-T7 AZ9l-HTS AZ91A-TI

...

...

...

...

...

...

...

...

285 28.5 40.0 40.0

40.0 29.0

44.0

26.0

17.5

11.0

40.0

15.5

15.3

12.0

26.0 25.0 ... ... 44.0 27.0 39.0 27.0

Die d n g .uOy (tested with ns-cmt skin prrscnt) AZ91-AC AZ91A-F ... 33.0

15.5 155 23.0 231)

2 3 0 171)

...

141)

8.5

63

16.0

...

7.5

6.2

18.0 13.0 .._ .._ 22.0 141) 20.0 15.0

22.0

151) 15.0 20 20

32 331)

6.0

31.0

37.0

39.0

10.0

I .o

7.0

34.0

11) 71) ... .-- 45 401) 35 30.0

3.0

An An RB RB

RB RB

B

B

B

B

B

B

B

B

RB RB RB RB RB RB RB RB

RB

ODR 02SR - l R -I R

- l R -I R

- l R

-I R

-1 R

-1 R

- lR

-1 R

-lR

-lR

- l R -1 R -1 R - lR - lR -1R -1 R -1R

- l R

O M d 03od a3ad

0 .Wr . 02956 03540 O M d 0.-

...

...

...

...

...

...

...

...

Qo3d Qo3d a m 0.W 0113d O M d am 0.W

0.25d

.*.

...

... 20

...

...

...

...

...

...

... 1..

...

...

... _.. ... ... .._ ... ... ...

__.

.._

.._

...

..-

.._

...

26.0

15.0

9.8

85

... 14.0

10.5

8.1

._.

...

...

...

...

...

...

...

...

22.0 25.0 195 14.0

...

...

9.1

9.4

6.7

5.8

15.0

9.0

5.6

5.8

1..

...

...

...

...

.._

...

.._

175

2aO 24.0 _.. _..

15.0 8.1

7.0

6.8

4.6

...

...

5.7

4.0

3.8

16.7 11.5 18.2 13.8 15.8 10.8 14.6 11.8

.._

18.0 2311 16.0 9.5

12.5 13

6.6

... 4 6

..*

10.0

...

...

...

14.0 10.0 16.5 121) 13.0 I 0 0 126 111)

151)

_.. ... 15.0 95

11.0 6.0

...

...

..f

... 10.0

...

...

...

12.5 91)

15.0 10.0 9.6 70 11.8 10.1

15.0

1..

f..

...

--.

... I

130 / MagMHTum Alloys Fatlgue Data

-rar#w

lWIon8tmo,MPa Mllcld)#6Mpy Fig. 7 Bfpea of surface type on the fatigue properties of cast magnesium-aluminum-zinc alloys. Source: Memls Handboo&, 9th ed., %I 2, ASM International, 1979, p 461

Temperature, OF 100 X X I 304 400

12 .i

't

115 H

Tharlum alloy Ran earth alloy . Thorlum alky

I Alumlnum alloy

0 50 100 150 xx) 250 Temperature, '"C

piot 8 Bffsctof ternpenuurc on the fatigue sadurana of some magnsrium casting alloys. Source: Ref 39

LAl41, Mg-14Li-lAl), bnt uses for these alloys have been limited to special applications such as components for spacemft and body armor.

Wrought Forms Extmded bar8 and ohapes are made of several types of magnesium

alloys. For normal strength requirements, OM: of the magnesium-aluminum-zinc (AZ) alloys is usually selected. The strength of tbese alloys increases as aluminum content increases. Alloy AZ31B is a widely used moderate-strength grade with good formability; it is used extensively for cathodic protection. Alloy AZ31C is a lower-purity commercial variation of AZ3 1B for lightweight structural applicatiohs that da not require maximum corrosion resistance. The Ml Aand ZMZlA alloys can be extruded at higher speeds than AZ31B, but they have limits! usebe- caustoftheirlowerstffngth. Alloy AZlOAhasalow aluminumcontent and thus is of lower strength than AZ3 IB, but it can be welded without subsequent stress relief. The AZ61A and AZBOA alloys can be artificially aged for additional strength (with a sacrifice in ductility); AZSOA is not available in hollow shapes. AUoy AZ21X1 is designed specially for use in battery applications,

Alloy ZK60A is used w h m high strength and good toughness am required. This alloy is heat treatable and is normally used in the artificially aged ("5) condition. W(21A and ZKMA alloys are of lower strength and are more readily extrudable than ZK6OA; they hare had limited use in hollow tubular strength requirements.

Alloy ZC71 is a member of a new family of magnesium alloys containing neither aluminum nor zirconium. The alloy can be extruded at high rates and exhibits good strength Properties. The corrosion resis-

Magnesium Alloys Fatigue and Fracture / 131

Tabla 7 Nomlnal compoaltkn, typkal tenslk properlh~, and characterktica of wlactad wrought magneolum rlloyr

M1 AM503 ...

Aal w1 3

AZ61 AZM 6 5

AZ80 A280 8.5

zM21 ZMZl .I,

mall I . . ..I

LA141 I.. 1.2

zK31 zw3 .,.

ZK61 .,. ...

wK31 ... a , .

W l ... .I,

.I, , . I

1 0.3 (0.20

1 0 3 (0.15 min)

(0.12 min)

0.5 0.2

2 1

6.5 0.75 0.15 min

3 I ,*

6 4..

,., ...

... 0.8

1.5

,..

I,.

.,.

(.,

. , I ... 0.6

0.8

0.7

. . I

. ( I

..I

...

I . .

I.,

... , I .

I,.

.,.

3,2

2

m 130 105 120

160 130 105 180

160 200

im

165 155 125 300 95

210

205 210 240

1160 170

180 135

I80 175

200

230 200 240

250 wl 200 260

215 290

240

250 235 200 325 115

295

290 21u 303 215 230

255 215

255 225

4

4 4 11

6 4 4 I

7 6

11

6 8 9 3

10

a I 6 4 7 4

4 6

4 3

High-saungth alloy, weldable

Mcdium-strmgthrlloy, good fomrability, good damping csplritY

mce of zc71 is similar to that of Az9 1 C, but it falls far short of that of AZ91E.

Alloy HM3 1A is of moderate saength. It is suitable for use in applications requiring good strength and c n e p resistance at temperatures in the range of 15Ot042J "C (300 to 800 OF).

Forgings aremadeofAZ3 IB, AZ61A, AZ80A, MIA, andZK6OA. AlloyHM21Aisalsoagoodforgingalloy. Alloys MlAandAZ31Bmay be used for hammer forgings (whereas the other alloys are almost always press forged); however, there has been a gradual decline in the use of the magnesium-manganese alloy MIA. The AZ80A alloy has greater strength than AZ61A and requires the slowest rate of deformation of the magnesium-aluminum-zinc alloys. Alloy ZK60A has essentially the same strengthasAZ80Abut withgreaterductility.Todevelop maximum properties, both AZ80Aand ZK60A are heat treated to the T5 condition; M A may be given the T6 solution heat treatment, followed by artifi- cial aging to provide maximum creep stability. Alloy HM21 A is given the T5 temper. It is u s e l l at elevated temperatures up to 370 to 425 "C (700 to 800 'F) for applications in which good creep resistance is needed.

Hydraulic and mechanical processes are both used for the forging of magnesium. A slow and controlled rate of deformation is desirable because it facilitates control of the plastic flow of metal; therefore, hydrau- licpressfwgingisthemostcommonlyusedprocess.Magnesium, which has a hexagonal crystal structure, is more easily worked at elevated tem-

peramre. Consequently, forsing stock (ingot or billet) is hcated to a temperature between 350 and 500 OC (650 and 950 "€9 prior to for@ng.

Sheet and plate are rolled from magnesium-alumhum-m (AZ and photoengraving grade, or PE) and magnesium-thorium (HK and

Alloy A 2 3 1 B is the m s t widely used alloy for sheet and plate and is availableinseveralgrades andtempen. Itcanbeusedattemperahlnsup to 1O0C (200°F). TheHK31AandHM21Aalloysaresuitableforuse at tetllperatures up to 315 and 345 'C (600 and 650 OF), mpa3ively. However, HM2lA has superior strength and aeq, resistance, Alloy PE is a special-quality sheet with excellent flatness, corrosion resistance, and etchability. It is used in photoengraving.

HM) alloys.

Wrought Mechanical Properties W i c a l mechanical properties data for various wrought alloys are

shown in 'Igbles 3 and 7. More detailed information on property minimums is c o v d in Ref6 and in Volume 2 of the ASM Handbook, Pmp enies and Selection: Nonfermus Alloys and Special-Purpost Maetials. In general, the direction, temperature, and speed at which an alloy is fabricated have a significant effect on the mechanical properties of wrought

have lower strength than drosepmduced undernmrralopaating conditiom. pam. Foratample, attrusionsproctuced arhighertempenwres and speeds

-. 0 N mble 8 Wrought magneslum alloy fatlgue strength \

AwlB-F(ml~ded) Az31x AZ1IB-F AZ31X AZ31B-F A23 IX AZ31B-F Az31x AZ31B-F Az3 1x AZ3 I B-F AUlX AZ3IB-F Az31x AZ31B-F Az31x A73 1 B-F

40.1 29.9 45.6 39.6 62.8 48.4 40.0 30.0 39.5 29.0 37.0 24.0 40.0 30.0 40.0 30.0

1- B -lR 15.0 B -lR as B -1R

15.0 RB -IR 16.0 RB -lR 19.0 RB -IR 15.0 B -IR 15.0 RB -1R

30.0 420 45.0

241) 22.0 30.0 26.0 320 _.. 27.0 ... 23.5 21.0 ... 215 17.0 ... 16.0 _..

19.0 23.0

21.0 18.0 20. I 10.0 10.5

...

... ... ... ... ... ... ... ... 2

-.. A-IOST A-3PT

...

._. A1 150°F

...

... ...

... 0.W

... 19.0 16.0

10.0 9.0

... ... ... ... ...

... 0.1171.1.Ow amr. 0 . 2 m 03540

.-.

A%lA-F(ertruded) m 1 x AZ61A-F AZ61X A261A-F m1x AZ61A-F

45.0 32.0 445 29.0 45.0 32.0

15.0 RB -IR 18.0 RB -lR 15.0 RB -1R

O M d O m

01)295r. 0.2956

245 ... ._. 27.0 I&O _..

ms 24.0 11.5

201) 21.0 10.0

6.0

...

..- 2

...

.._

... ...

At 150'F .-.

AZ61X AZblA-F 45.0 32.0 15.0 RB -Ir 0.3540 6o"mcdr.

O.o02r, o w . 0.4800

0.llQ 1 . b

5 11.5 _.. 6.5 ... ...

AZ61X AZ61A-F 45.0

AZIIOA-F(extruded) Azllox AZ80A-F 46.5 AZBOX -A-F 48.5 mox AZ80A-F 35.0 Azllox AZ80A-F 49.0 m o x AZ80A-F 49.0

32.0 15.0 B -lR 19.0 _.. 135 135 ... ... ...

33.5 12.0 RB -lR 32.3 15.0 RB -1R 26.0 39.0 RB -1R 33.0 11.0 RB -1R 33.0 11.0 RB -IR

0-3tkf 03W 0-W

0.0295r. 0.29%. 0.3540

_..

B.0 ... ... 16.5 10s

26.0 22.5 28.6 24.0 15.6 13.5 ... 125 .._ 7.0

19.0 22.4 I 2 0 11.0 6.0

... ... ... ... ... ...

... At 150°F At 275 "F

...

...

... 2 ...

AZWA-T51 (extruded) AZBOX-A AzBOA-T5I 43.0 29.0 23.0 RB -lR Wnolm,

0 . m o.w, 0.48012 0.W

5 24.0 21s 200 At 150°F ...

AZ80X-A AZ8OA-T51 32.0

AZ&OA-T51 (longiIudi~I,extnuled) -OX-A Az8oA-T51 50.0

21.0 41.0 RB -IR 16.3 14.0 At 275 "F ... ... ...

34.0 6.0 B -lR Unaadwd 0.1161.1.0N 195 ... 13a 13.0 ... ... ... AZ8OA-T51 (extruded) AZAOX-HIA AUUIA-T5I AZ8OX-HU AZBQA-TSI AZ8OX-wL4 AzBOA-T51 AZ8OX-HIA AUUIA-TSI AZSOX-HU AZ8OA-T51

Au#IA-F(longitmdinal, extruded) Az8oX-H'lA AZ80A-F AZBoX-HlA AZ8OA-TSI Az80A-TSl (wrought) AZBoX-HlA AZ80A-TSI

34.0 7.0 RB -lR 37.5 13.0 RB -IR 32.0 m.0 RB -lR 23.0 31.0 RB -1R 21.5 35.0 RB -lR

27.0 ... 23.0

20.6 ...

.._ 225 25.4 23.0 17.9 13.0 163 14.0 152 11.0

20.5 20.4 13.0 113 105

50.0 54.0 48.5 37.0 335

0.W 0.W O m 0.W 0.W

... At 150°F At200-F At 275 "F At 300 "F

...

...

...

.-.

...

...

...

...

...

...

50.0 50.0

34.0 7.0 B -lR 34.0 5D Ax OR

unmcehed Unaadwd

0.114 1 . h 0-

ma 39.0

... 12.5 35.5 320

125 ...

...

... ... .._

.._

...

50.0 34.0 5.Q Ax 0.2% Uomcbcd 0.W 39.0 36.5 34.0 ... ... ... _..

(continued)

Table 8 Wrought magnesium alloy fatigue atrsnglh (contlnud)

AzBoA-T51 (wrought) (mtioued) AZ8OX-HIA AZ8OA-TSI AZ8OX-HIA AZ8OA-T51 AZ8OX-HIA AZ80A-T51

Az80A-TSl (extruded) AzBax-Ifc4 Az8oA-T51

MI-F(utrodcd) M- 1 MI-€ M- 1 MI-F

M- 1 MI-F

MI-o(aheel) M-la MI-0 M-la M I 4 M-la MI-0

EMSlXA-T6 (wmught) M I - H I A EM61XA-T6 EM5l-HIA WlXA-T6 EMSI-HTA EM5IXA-T6

EM6lXA-F(extruded) EM61 EM61XA-F

EM6lxA-Tz (extruded) EM61-S EM6u(A-T2 EM61-S EM61XA-T2

A M l o O A P ( f ~ A-10 AMIOOA-F A- 10 AM IOOA-F

Az6lA-F(fod) m1x AZ61A-F Az6 IX Az61A-F

AZSOA-F(fOrbed1 mox AZEOA-F AZWX AZ80A-F

mox AZSOA-€ m o x A28OA-F

49.0 30.0 ...

57.5

57.5

38.0 38.0

38.0

34.0 23.0 20.0

37.0 25.0 24.0

...

... 30.0

...

...

43.0 43.0

46.0 46.0

51.0 B.0

30.0 11.0 ...

40.5

40.5

26.0 26.0

26.0

19.0 14.0 12.0

28.0 15.9 15.3

...

1..

26.0

...

...

26.0 26.0

31.0 31.0

31.0 19.0

7.0 35.0 ...

4.0

4.0

10.0 10.0

iao

12.0 25.0 M.0

5.0 iao iao

...

1..

14.0

...

...

120 12.0

8.0 8.0

15.0 Xi0

Ax Ax Ax

RB

RB

RB B

RB

Ax Ax Ax

Ax Ax Ax

RB

RB RB

RB RB

RB RB

m RB

RB RB

025R 0- 02JR

-lR

-lR

-lR -lR

-1R

02SR O Z R 025R

025R 0.m O m

-lR

-lR -lR

-IR -lR

-lR -lR

-1R -1R

-lR -lR

Uomotcbcd _._ umrarbed .._ Umrmched ...

cilcuhwrh 0.0295r. 0.295d. 0.3yID

v-aach w(pmcb. O a M r . 0 ~

0.480

03od 0.125r. I.ow.

0.0295r, 0295d 03540

.._

...

...

... _.. ...

...

__. ...

03od a3aD

aMd 0.02% 0.m. 0.3540

a3Qd ao295r. 029Iid. 03540

0.W am

...

...

.._

2

5

_._ .._

2

...

...

.._

...

...

._.

_..

.._

...

._.

._.

.._ 2

-.. 2

...

...

_.. .._ ...

...

...

...

...

._.

25.8

26.2 ...

35-0 35.0 29.0

...

1..

1..

...

...

_.. _..

...

...

_.. -._

36.8

24.5 26.5

17.0

11.0

155 14.0

11.0

23.3 22.0 21.0

31.0

23.4 27.5

_..

...

...

...

...

ns 14.5

28.0 163

...

...

343 24.8 16.5

...

_._

...

._.

1..

21.0 18.6 165

28.0 23.0 18.0

185

19.0 17.6

17.6 13.0

_.. ...

...

...

24.6 15.8

33.0 23.0 11.0

13.0

8.0

10.9 10.0

7.0

21.0 16.6 13.0

25-0 22.0 15.6

17.5

18.2 15B

15.0 9.9

215 111)

22.0 115

22.0 12.7

.._

...

...

11.0

1.0

10.5 iao

5.5

*.. ... ...

...

.-.

...

15.0

16.0 126

12.0 7.7

195 9.5

19.5 10.5

I95 9.3

...

...

...

.._

...

... Atz0o"F At300°F

Faiguedatmt 150°F

f 2 s

Faigwdataa 150°F F;lliguedacaa 275 O F

...

._.

...

0 Fatiguedataat IM"F 3 Fatigue damp 275 OF P

Note: UTS, ultimate tensile stren@qYS, yieid etamgth; %I$ percent- B. bendiqe; R B , F o t a t i s p b k &d, inaide di.mater , D, outaide d*mster; t.- r, HJ. Grover, S.A. Gordon, and L.R. Jackson, Fatigue ofM& andStr&uws, Depmbea&dthe Navy, 1960, ~316363

w, wid* W, notchwidth. &mnx

a (continued) N

2 5 \

Table 8 Wrought magnesium alloy fatigue strength (continued)

UT$ kfi Mmtehl Designation

AZ%OA-TS (forged) AZBOX-A AZ8OA-TS AUUIX-A AZ8OA-T5

... ... 25.0 ... m.0 18.0 ... 2 ... 165 ... 9.5 9.5 ...

50.0 50.0

34.0 34.0

6.0 RB -lR unnotchcd 0.W 6.0 RB -IR Ciculanoach O.O2!L5r,

0.2954- 0.3540

Unnotdwd 0.W ... RB -lR Unnotched 0.W 520 RB -IR unnotdwd 0-W

85 RB -IR AZIOX-A AZBOA-TS AZ8OX-A AZ8OA-TS AZBOX-A AZ8OA-T5 m 0 X - A AZ8oA-TS

50.0

26.0 26.0

... 34.0

14.9 14.9

... ... ... _.. 22.3 m.0 17.7 FatigueCrar 150°F ... ... ... 14.2 11.8 100 Fsi- dam ill 275 "F ... ... m.5 ... 11.0 IOS All dataar 300 "F c 2 ... 10.5 ... LS 5.0

5 All h a ( 300 "F 0 RB -IR Ci~~~L;rnotch 0.029%.

0.2%. 0.3541)

5 2 0

AZ%OA-T6 (for@) AZ8OX-H'TA AZ8oA-Td AZ80X-HzA AZ8OA-T6

161) 9.5

49.0 49.0

30.0 7.0 RB -IR 30.0 7.0 RB -IR

Unnorhed cilaroach

0-W 26.0 14.5

...

... K O 9.5

...

... ... 2

...

... 0.029%. 0.2954. 0.3.54D

AZlWA-T6 (forged) AZBOX-H'TA Az8oA-T6 AZBOX-HI# AZ8OA-T6 AZBOX-HTA AZ8OA-T6

45.7 43.0 43.0

17.0 9.0 RB -IR 14.3 14.0 RB -IR 14.3 14.0 RB -lR

Uonached uonotehed

cilanotch

0.W O..W

0.029%. 029Sd. 0.3540 0.m 020l ...

0.- 0.m 0.33

20.0 17.5

18.0 13.0 7.5

16.0 130 7.0

Alldmat IW0F Alldalaat200"F All &a at 2M) "F

...

...

...

... 23.0 12.7

...

... 2

AZ80X-HlA AZ8OA-Tb AZBOX-HM AZ8OA-Tb AZ80X-H"A Az&oA-T6

AZ8OX-HTA AU#)A-T6 AZ8OX-HTA AZ80A-T6 AZ8OX-KIA AZ8OA-T6 -OX-HIA AZ8OA-T6

12.5 30.0 RB -IR 30.0 1.0 B -1R 11.0 35.0 RB -lR

11.0 35.0 B -IR B -IR

11.0 35.0 RB -IR 11.0 35.0 RB -lR

... ...

15.1 16.8 15.2

7.5 7.5

15.2 .-.

12.5 16.0 11.0

6.0 5.0 11.0 M

10.5 Allda1aa127S"F

All damat 3M) "f3W%ax-rn

All dmr 300 "F Faigue data a~ 400 OF

All h a t 300 "F All damat 300°F

... 36.0 49.0 30.0

30.0

30.0 30.0

...

...

...

...

m.0 m.0 ... ...

... X.5 20.6

12.0 12.0 20.6 10.8

...

... ... 10.5

... ... ... 10s 5.0

...

... 2 0.029%.

0.29-W. 03S4D

EM21XA-F (forged) EM2 1 EM2 I XA-F EM21 EM2IXA-F

EM41XA-F(forged) EM41 EM41XA-F EM4 I EM41XA-F

EWIXA-T6 (Ibrged) EM51-€IT4 EM51XA-T6 F.M.51-HTA EMSIXA-T6

Faiguedaaa 150°F Friguedataa 275 "F

... ... RB -lR

... ... RB -lR Unnoatvd Unnotdvd

0 3 0.W

16.0 13.6

15.0 12.6

13.0 12.0

...

... ... ...

...

... ... ...

37.0 21.0

27 .O 81) RB -lR 22.0 14.0 RB -lR

Unno(chcd Unnophed

030d 0 3

17.7 17.8

16.2 16.6

14.0 16.0

Faigueduaat 150°F Faiguedwr 275 "F

...

... ... ...

...

...

37.0 ...

28.0 5.0 RB -lR ... ... RB -IR

Unno*bed C i l a w C m

030d 0.0295r. 029%. 0.3540

0 . a 0.m

...

...

16.5 12.0

15.0 ...

133 a 3

12.0 7.0

... 2

...

... ... ...

EM51-HTA EM51XA-T6 EMSI-HTA eM51XA-T6 EM5I-MA F.M.51XA-T6 E M S 1 - m EMSIXA-T6

37.0 25.0 24.0 13.8

28.0 5.0 B -IR 15.9 16.0 B -IR 153 18.0 B -lR 1.4 18.0 B -IR

23.0 18.0 15.5 13.0

18.3 15.0 127 8.8

14.5 122 98 6.3

12.5 9.4 8.0 3.7

...

...

... _..

...

...

...

...

{continued)

Table 8 Wrought magnesium alloy fatigue strength (continued)

Fmtipelaadii Fatigue spn *men Fatigwstrm~((nustmss),bi,atidkakdcydes: Materlal Designation ksi UE Type C & i Typ size, In K. I& 10' Idb 10' 10s comments

MIA-Ftforped) MI-a MI A-F MI-a MIA-F MI-a MIA-I' MI-a MIA-F

EMSIXA-F (forged) EM51 EMS IXA-F EM51 EMSIXA-F EMS 1 EMS IXA-F EMS I EMS 1%-F EMS I EMSIXA-F

A Z 3 1 A a (longitudinal, sheet) AZ1 IX-a AZ3 IA-0 AZ31X-a AI3IX-0

M.0 23 0 20.0 17.2

...

...

...

...

...

37.0 37.0

43.0 43.0

37.0 37.0

43.0 43.0

37.0 37.0 77.0

43.0 43.0 46.0 46.0 43.0 43.0

19.0 13.8 12.0 9. I

. .

. .

...

...

...

22.0 220

33.0 33.0

22.0 22.0

33.0 33.0

22.0 22.0 20.0

37.0 37.0 38.0 38.0 33.0 33.0

12.0 26.0 31.0 -34.0

...

...

...

...

...

21.0 21.0

11.0 11.0

21.0 21.0

11.0 11.0

21.0 21.0 21.0

11.0 11.0 5.0 5-0 11-0 11.0

B B B B

B B B

Ax Ax

B B

B B

B B

B B

Ax Ax Ax

Ax Ax Ax Ax Ax Ax

-lR -IR -IR -IR

-IR -lR -lR

0.ER 0.25R

-IR -lR

-1R -lR

-lR -lR

-lR O Z R

0.25R 0-SOR 0.m

0.25R OSOR 0.25R 0-WR 0.25R OSOR

... 19.0

... ...

... ...

... 13.9

13.0 9.0 7.0 ... ... 11.7 ao 5.8 ... AUdaraSr2W"F 18.0 7.4 6.0 ... AUdataS3000F 9.5 6.5 5.0 ... AUdataSr'UXlOF

... O B O B 0-

0.m 0.201 0.201 0.201 0.m

0.m. oJ(hu 0 . e . O m . 0.525~. amw

0 .mL 0.5ow 0.062r. 0.0201. 0.525~. 0.65~

0.064f.OfiW

.._ 18.0

... 16.7

... 10.4 _.. 32.0 ... 30.0

14.2 11.0 8.9 ... AlldPts913(XJ0F 122 9 2 7.5 ... AlldataatMW)"F 8.3 65 5.0 ... All data pt 300°F 301) 27.5 255 _.. ... 242 19.7 16.0 ... .._

19.5 ... 15.5 15.5 ... 17.0 ... 13.0 13.0 ...

... ... 1 -6 ...

AZSlA-HZ4 (longitudinal, sheet) AZ31X-h AZ31A-H24 AZ3 IX-h AZ31A-H24

19.5 17.5 13.0 11.0

20.0 ... 19.5 ...

_.. ... 1.6 ...

._.

._.

AZ3lAO (loogitudinal, sheet) AZ3IX-a AZ? I A-0 AZ3IX-a AZ" 1 A-0

15-0 ... 14.0 135 18.0 ... 13.0 ...

... ... 2 ...

...

._.

AZ31A-RZ4 (longitudinal, sheet) A23 I X-h AZ31A-EI2-4 AZ3 I X-h AZ31A-H24

Ummtcbed O.Wr.0.65~ Sllrfxendch wn4ch.

0.OOIr. 0.65w.

0.m. 0.m

17.0 ... 15.5 151) 21.0 ... 15.0 .._

... ...

... ... ... ...

AWIA-O (sheet) AZ71X-a AZ3 I A-0 A z 3 IX-a AZ1 IA-0 AZ31X-a AZ1 IA-0

AZ31A-IW (sheet) AZ3 IX-h AZ3 IA-H24 AZ31X-h AZ31A-H24 AZ31X-h AZ31A-H24 A23 IX-h AZ3 1 A-H24 AZ31X-h AZ31A-H24 AZ31X-h AZ31A-H24

21.5 21.0 21.0 ... _.. 28.0 27.0 26.0 ... _.. 26.0 21.0 20.0 ... _._

_.. ... _.. ... ... 32.0

36.0 35.0 34.0 ..- ... 39.0 36.0 351) .._ ... 28.0 25.0 24.0 .._ ... 37.0 30.0 29.0 ... ... 24.0 238 23.0 ... ... 28.0 260 26.0 ... 1..

... ...

... .._

... 40.0

... ...

... ...

... ... 0 J a

Table 8 Wrought magnesium alloy fatigue strength (continued) s AZSIXA-0 (longitudinal, sheet) A25 IX-a A25 IXA-0

AZ51XA-H24 (longitudinal, sheet) AZSIX-h AZ.5 1XA-H24 A25 1X-h A7SlXA-HZ4

14.0 ... 41.0

44.0 44.0

44.0

43.0 43.0

47.0 47.0

43.0 43.0

47.0 47.0

43.0 43.0 43.0

47.0 47.0 46.0 46.0 46.0

33.0 33.0

22.0

33.0 33.0

33.0

26.0 26.0

34.0 34.0

26.0 26.0

34.0 34.0

26.0 26.0 26.0

34.0 34.0 35.0 35.0 35.0

15.0 15.0

18.0

9.0 9.0

9.0

16.0 140

9.0 9.0

16.0 I40

9.0 9.0

16.0 140 16.0

9.0 9.0

120 12.0 12.0

17.0 17.0

B

B B

Ax

B B

B B

B B

B B

Ax Ax Ax

Ax Ax Ax Ax Ax

Ax Ax

-IR

-IR -IR

025R

-IR -IR

-IR -IR

-IR -1R

-IR -IR

025R OSQR OSQR

0.25R 050R 0.25R 0- 0.7%

O Z R 0.W

19.5 ... 145

16.0 15.0

28.0

15.0 115

2113 105

14.5 25.5.

1613 16.5

18.0 29.0 23.0

21.0 a13 23.0 25.0 30.0

145 22.0

... ...

unnotehed 0.w. I.& Surfacenach 6o"notch.

0.003d. 0.001 r.

Q064r. a6.5 W unndched 0.w.l.Ow

24.0 ... 225 ...

I 4 0 _.. ... ...

... -.. 20 ...

A25 1X-h AZ51XA-HZ4

AZ61A-0 (longitudinal, sheet) AZ6lX-a AZ6 I A-0 AZ61X-a AZ61A-0

34.0 29.0 ... ... ... ...

UnmCcbEd 0 ~ 0 . 5 O w 23.5 ... 15.0 ...

14.0 ... 115 ...

... ... 1.6 ...

AZ61A-H24 (longitudinnl, sheet)

AZ6IX-h AZ6lA-H24 AZ6IX-h A Z ~ ~ A - H M ...

... Unndched om.o.5ow Edgenotch 0.062r.

0.m. os25n: 0.45 w

30.0 ... 15.0 ...

18.0 10.5

... ... 1.6 .-.

AZ61A-0 (longitudinal, sheet) AZ61X-a AZ6 I A-0 AZ61X-a AZ61A-O

unwrched 0.064L1.Ou. Fdgenach 0.063.

0.020l. 0525K. O.&5W

18.0 ... 24.0 ...

14.0 ... ... ...

... ... I .6 ...

AZ6lA-Htd (longitudinal, shnt ) AZ61X-h AZ61A-H24 AZ61X-h A26 IA-H24

urmotched 0 . w . 1 . b OM>.

0.020r.525~. 0.65 w

19.0 ... 21.0 ...

15.0 ... ... ...

... ... I .6 ...

AZ61A-O (sheet) A26 IX-a AZ6 I A-0 A26 IX-a AZ61A-O AZ61X-a AZ61A-O

AZ6lA-H24 (sheet) A261X-h AZ61A-H24 A261X-h AZ61A-H24 AZ61X-h AZ6lA-H24 AZ61X-h AZ61A-H24 AZ61X-h A Z ~ I A - H ~ ~

M1A-O (sheet) MI-a M I A 4 MI-a MIA-0

UNIOKbed O a 6 4 r . 1 . ~ unwcfhed 0.064f. 1.w u- 0.064#.05Ov

24B 20.0 311) 24.0 311) 24.0

... ...

... ... -.. ...

... ...

... _..

... ...

UnmNChed 0 . m l.w uooaebed 0 . w . l ~ unwcehcd 0.064#,o..sow urmacbcd 0.m.o.5ow uaooccbed 0.m.o.sow

241) 21.0 34.0 25.0 250 24.0 33.0 26.0 37.0 31.0

... ...

... ...

... 40.0

... 41.0

... 44.0

... ...

... ...

... ...

... ... _.. ...

17.0 145 na 220

_.. ... ... ...

... ...

... ...

Thbk 8 Wrought nragndunr alloy Mgue strength (conhwd)

m-w) M1-b MIA424 MIA M1A-H24

M I A 4 -sIK&) MI-a MIA-0 MI-a MIA-O

M l r M I A 4 MI% MIA-O

MI4 MIA-H24 M I 4 MlA-H24

371) 37.0

33.0 33.0

33.0 339

31.0 37.0

3.0 31.0

m - T S n3oA-n ... 48.0 ZKm-n ... 48.0

zK6(M-T5 _.. 481) =-T5 ... 48.0

zK6M-TJ: ... 48.0 zK6oA-T5 ... 48.0

29.0 29.0

15.0 15.0

15.0 15.0

29.0 29.0

29.0 29.0

40.9 40.9

40.9 40.9

40.9 40.9

8.0 so

17.0 17.0

17.0 17.0

8.0 8.0

8.0 so

...

.-.

_._ _..

...

...

Ax Ax

B B

B B

B B

B B

Ax B

Ax Ax

Ax Ax

O H 05oA

-lR -1R

-lR -lR

-lR -lR

-lR -lR

-lR -lR

aR OR

-lR -lR

Urmacbed 0.064t.1.Ow urmatrhed 0.064t.l.Ow

unaacbed am.i.Ow E d g e d 0 . e .

m. 0525w. 0.65 w

urmotched O . ~ , l l l w SlufacenaEh 60"-

0.001 r, 0.W.

O . W , 0.65 W

...

...

... 1.6

_.. 20

... 1.6

... 20

... 28

_.. 29

.._ 2.9

_.. ...

...

...

...

...

._.

...

...

...

36.0 a 0

50.0 25.0

30.5 151)

27.0 235 320 27.0

I&O ._. 1QO ...

135 ... 15.5 _..

16.0 ... la5 _..

16.0 ..- 15.5 ...

24.5 m.0 15.0 115

40.0 33.0 13.5 125

23.5 205 11.0 9.0

23.0 26.0

10-0 5.0

9.0 95

10.5 5.0

10.5 10.0

18.5 8.5

32.0 120

19.9 KO

... ...

... ...

10.0 ... 5.0 ...

7.5 .._ ... 1..

105 4.5

105 ...

180 7.0

32.0 120

...

...

... _..

...

...

...

...

19.0 ... 8.0 ...

Next Page

Magnesium Alloy Fatigue Data Collected by R.I. Stephens and C.D. Schrader, Mechanical Engineering Department, The University of Iowa

Mg-AI Casting Alloys

Composition: 9.9A1-0.10Mn-bal Mg Product form: Casting, permanent mold cast Heat treatment: F, T4, T6 Modulus of elasticity (avg at RT): 45 GPa (6.5 x lo6 psi) RT tensile strength/elongation: F 150 MPa (21 ksi)/2%.

T4: 275 MPa (40 ksi)/lO%. T6: 275 MPa (40 ksi)/4%

RT yield strength: F: 85 MPa (12 ksi). T4: 90 MPa (1 3 ksi). T6: llOMPa(l6ksi)

Test temperature: Room temperature Test environment: Air Failure criterion: Fracture Loading condition: Rotating bending ( R = -1) Specimen geometry: Same notched, Kt = 1 and 2 Surface: Smooth Source: J.D. Hanawalt, C.E. Nelson, and R.S. Busk, Proper-

ties and Characteristics of Common Magnesium Casting Alloys, AFS, V0153.1945, p 77-86

Table 1 AM100A Rotating bending, R = -1 fatigue strength for permanent mold castings

Fatigue strength at: 106cycles 108 cycles

Condition MPa ksi MPa hi

Smooth, Kt = 1 F 110 16 82 12 T4 124 18 % 14 T6 110 16 76 11

Notched, Kt = 2 F 69 10 48 7 T4 82 12 55 8 T6 76 11 62 9

Composition: 6.OA1-0.15Mn-3.0Zn-bal Mg Product form: Sand cast Heat treatment: F, T4, T6 Modulus of elasticity (avg at RT): 45 GPa (6.5 x lo6 psi) RT tensile strengthlelongation: F: 200 MPa (29 ksi)/6%.

T4: 275 MPa (40 ksi)/l2%. T6: 275 MPa (40 ksi)/5%

RT yield strength: F: 95 MPa (14 ksi). T4: 90 MPa (13 ksi) T6: 130 MPa (19 ksi)

Table 2 AZ63A: Fatigue strength of sand cast test bars

Test temperature: Room temperature Test environment: Air Failure criterion: Fracture Loading condition: Rotating beam ( R = -l), axial ( R = 0.25) Specimen geometry: Unnotched Surface: Smooth Source: “Dow Data Sheet on Fatigue Properties,” Dow

Chemical Co., 20 May 1958; “Aerospace Structural Met- als Handbook,” Battelle Columbus Laboratories, 1991, p 2

Rotating beam,R = -1 F 103-124 15-18 82-103 12-15 69-89 10-13 65.5-82 9.5-12 T4 124-158 18-23 110-144 16-21 96-131 1419 89-117 13-17 T6 117-138 17-20 103-124 15-18 82- 110 12-16 76-103 11-15

Direct stresqR = 0.25 F 15 1 - 172 22-25 138-158 20-23 124-144 18-21 ... ... T4 158-186 23-27 144-165 21-24 124-144 18-2 1 ... ... T6 172-207 25-30 158-172 23-25 151-172 22-25 ... ...

152 / Magnesium Alloy Fatigue Data

Composition: 6.8AI-0.33Mn-3.lZn-0.0lC-0.009Cu-0.009

Heat treatment: T4 Modulus of elasticity (avg at RT): 45 GPa (6.5 x lo6 psi) RT tensile strength/elongation: 260 MPa (37.8 ksi)/6.9% RT yield strength: I68 MPa (24.4 ksi) Test temperature: Room temperatun: Test environment: Air Failure criterion: Fracture Loading condition: Rotating beam, R = -1 Specimen geometry: Notched, K, = 1.69 Surface: Smooth Frequency: 10,OOO rpm Source: R.B. Clapper and J.A. Watz, Determination of Fa-

tigue Crack Initiation and Propagation in a Magnesium

Fe-0.00lNi-0.~5Pb-0.~Si-0.0 1 Sn

Alloy,ASTMSTP 196,1956, p 111-1 19 1 o5 1 06 107 1 06

Cycles. mean life

Fig. 1 AZ43A-T4 S-N curve for cast and notched specimens

Composition: 9.OA1-0.13Mn-0.68Zn-baI Mg Product form: High-pressure die cast Heat treatment: F Modulus of elasticity (avg at RT): 45 GPa (6.5 x lo6 psi) RT tensile st~ngthjelon~ation: 230 MPa (33 ksi)/3%

2 RTyieId strength: 160 MPa (23 ksi) Test temperature: Room temperature I: Test environment: Air 6

E tj Failure criterion: Fracture

Loading condition: Axial Specimen geometry: Separately cast test bars Surface: As cast Source: “AZ91A-F Die Castings, R.R. Moore Fatigue

Curves,” Dow Chemical Co., TS&D Letter Enclosure, 3 March 1957; R.S. Busk, Magnesium Productf Design, Marcel Dekker, 1987, p 280

1 o4 I o5 1 o6 10’ 1 o8 cyctes

Fig. 2 A291 B. Axial fatigue of die cast bar

Composition: 9.0A1-0.13Mn-0.68Zn-bal Mg Product form: High-pressure die cast Heat treatment: F Modulus of elasticity (avg at RT): 45 GPa (6.5 x lo6 psi) RT tensile strengthjelongation: 230 MPa (33 ksi)/3% RT yield strength 160 MPa (23 ksi) Test temperature: Room temperature 5

s Test environment: Air vi Failure criterion: Fracture p! Loading condition: Rotating beam tj Specimen geometry: Separately cast test bars Surface: As cast I

Source: “AZ91 A-F Die Castings, R.R. Moore Fatigue I -8 . . Ronout

40 . . , , . . _ _ I , , . ..... , , . ._... , . . ._... . . Curves,” Dow Chemical Co., TS&D Letter Enclosure, 3 March 1957; R.S. Busk, Magnesium Fmdurrs Design, Marcel Dekker, 1987, p 279 1 o4 1 o5 106 1 O7 108 1 o9

Cycles

Fig. 3 A291 B R ~ ~ t i n g beam fafigue of die cast bar

AZSl 6, Plate Bending I 153

composition^ 9.OA1-0.13Mn-0.68Zn-bal Mg

Heat treatment: F Modulus of elasticity (avg at RT): 45 GPa (6.5 x lo6 psi) RT tensile stren~h~elongation: 230 MPa (33 ksi)/3%

2 RT yield strength: 160 MPa (23 ksi) Test temperature: Room ~ m p e r a ~ r e 2 Test environment: Air 6

m iij

Failure criterion: Fracture Loading condition: Plate bending 60 Specimen geometry: Cast panels Surface: As cast, edges machined Source: “‘AZ9IA-F Die Castings, R.R. Moore Fatigue

Product form: High-pressure die cast 140

100

Curves,” Dow Chemical Co., TS&D Letter Enclosure, 3 March 1957; R.S. Busk, Magnesium P ~ ~ u c t s Design, 1 04 I o5 106 1 08

20

Marcel Dekker, 1987, p 28 1 Cycles

Fi. 4 AZ91 B: Plate bending fatigue of die cast bar

Composition: 9.0A1-0.13Mn~.68Zn-ba1 Mg Product form: Sand cast Heat treatment: F, T4, T6 ~ ~ d u l u s of elasticity (avg at RT): 45 GPa (6.5 x lo6 psi) RT tensile strength/elongation: F 165 MPa (24 ksi)/2%.

T4: 275 MPa (40 ksi)/l4% T6: 275 MPa (40 ksi)/5%

RT yieid strength: F; 95 MPa (13 ksi). T4: 85 MPa(l2 ksi). T6: I30 MPa (19 ksi)

Test temperature: 25 “C (77 O F )

Test environment: Air Failure criterion: Fracture

Loading condition: Ksouse plate bending, R = -1 Surface: Machined, polished Source: “Tables of Fatigue Strength of Sand Cast Magne-

sium Alloys,” Dow Chemical Co., TSBD Letter Enclo- sure. 19 Nov 1965

Table 3 AZ91C: Bending fatigue of cast specimens

........., -. 10’ cyck 106 cycles 107 cycles

Amper MPa ksi MPa ksi MPIt ksi F 85 12 7.5 I 1 60 8 T4 10.5 1.5 8.5 12 75 I f T6 105 15 8.5 12 65 9

Composition: 9.OA1-0.13Mn-0.68Zn-bai Mg Product form: Sand cast Heat treatment: F, T4, T6 Modulus of elasticity (avg at RT): 45 GPa (6.5 x lo6 psi) RT tensile strength~~longation: F 165 MPa (24 ksi}/2%.

T4 275 MPa (40 ksi)/l4%. T6: 275 MPa (40 ksi)/5%

RT yield strength: F: 95 MPa (1 3 ksi). T4: 85 MPa(l2 ksi). T6: I30 MPa (19 ksi)

Test temperature: 25 “C (77 OF) Test e n v i ~ n m e n t ~ Air Loading condition: Rotating beam, R = -1 Specimen geometry: Some notched, Kt = 2 Surface: Smooth, m a c ~ n ~ , and polished Source: “Tables o~Fatigue Strength of Sand Cast Magne-

sium Alloys,” Dow Chemical Co., TS&D Letter Enclo- sure, 19 Nov 1965

Table 4 AZ9lC: Rotating beam fatigue strength

Fatigue stmngth at: Smmth Noghed

lo1 cycles 106 cycks 107cvcles loBcycles 106 cycles 1OScyeki Temper MPa ksi - W a ksi Mpa ksi MPa ksi MPa ksi MPa ksi F 110 16 105 15 95 13.5 85 12 70 10 55 8 T4 135 19 t i 5 16 105 15 95 13.5 75 11 60 9 T6 125 18 105 15 90 13 80 11.5 75 11 55 8


Composition: 8.7AI-0.13Mn-0.70Zn-bal Mg Product form: Sand cast Heat treatment: T6 Hardness: 61 HB Modulus of efasticity (avg at RT): 45 GPa (6.5 x lo6 psi) RT tensile strengthlelongation: 140 MPa (20 ksi)/3% RT yield strength: 1 I0 MPa (1 6 ksi) Test temperature: Room temperature Test environment: Air Loading condition: Strain control, R = -1 Source: R. Chemenkoff, private communication

Reversals to failure, 24 Fig, 5 AZ91C-T6: Strain-life diagram for cast specimens

Composition: 9.0A1-0 I3Mn-0 68Zn-bal high-purity Mg Product form: Sand cast 1 Hardness: 58 HB Modulus of elasticity (avg at RT): 45 GPa (6.5 x lo6 psi)

0 1 RT tensile strengthfelongation: 235 MPa (34 ksi)/5% RT yield strength: I60 MPa (23 ksi)

Test environment: Air “a 001 Loading condition: Strain control, R = -I Specimen geometry: 3.175 mm (0.125 in.) thick x 6 35 mm

(0.25 in.) wide i% 0001 Surface: Skin on Gauge length: 7.62 mm (0.3 in.) Source: R Chemenkoff, private communication

. 4 m 9 Test temperature: Room temperature I

E r: E

O O O o l I 10 id lo3 lo4 lo5 lo6 10’ lo8

Reversals to failure, 24 Fig. 6 A291 D-HP Strain-life diagram

Composition: 8.97AI-0.547~1-0.12Mn-0.0 1 OCu-0.0 1 Si-

Product form: Sand c a t blocks Heat treatment: T6 Modulus of elasticity (avg at RT): 45 GPa (6 5 x lo6 psi) RT tensile streu~h/elongati#n: 3 18 MPa (46 ksi)/lZ% RT yield strength: 142 MPa (20 ksi) Test temperature: Room temperature Test environment: Laboratory air Failure criterion: Fracture or 20% load drop Loading condition: Axial strain control, R = -1,0, and -2 Specimen geometry: Uniform gauge section, 4.35 rnm (0.25

Surface: Machined, longitudinal, and polished Gauge length: 13 mm (0.5 in.) Frequency: 0 5 to 30 Hz Strain rate: 0.015 to 0.33 s-’ Waveform: Triangular Source: D. Goodenberger, “Fatigue and Fracture Behavior

O.oO3Fe-0.00 1 0Ni

R = - l runout

in.) diameter

10 10’ 103 lo4 lo5 lo6 10’ Reversals to failure, 2N,

Fig. 7 AZ91E-T6 Low-cycle fatigue

of Az91E-T6 Sand Cast Magnesium Alloy,” Master’s thesis, The University of Iowa, Dec 1990

AZ9lE Fatigue Crack Growth / 155

Product form: Sand cast Heat treatment: T6 Modulus of elastidty (avg at RT): 45 GPa (6.5 x 106 psi) RT tensileatmgth/elongetion: 318 MPa (46 ksi)/12% RT yield strength: 142 MPa (20 h i ) Test temperature: Room temperature M environment: Laboratory air Lopding condition: Load control, R = 0.5 and 0.05

A R10.05 1 R=0.5

Composition: 8.97Al4.54Zn-0.17Mn4.010Cu-0,01 Si- 0.003Fe-O.00 1 ONi lo

spedmen geometry: Compact type

- 1 ,:*iy ‘. R = 0.05 . . . Surface: Polished .., Frequency: 20 to 40 Hz Waveform: Haversine 10 Source: D. Chdenberger, ‘Fatigue and Fracture Behavior 1 10

of AZ91E-T6 SandCast Magnesium Alloy,” Master’s AK MPa h thesis, The University of Iowa, Dec 1990

ETg.8 AZ91E-T6: Fatigue crackgrowth behavior

Composttion: 8,97A1-0.54Zn-O. 17Mn-0.010Cu-0.01 Si- 0.003Fe-0.0010Ni

Product fom: Sand cast Heat treatment: T6 Modulus of elastidty (avg at RT): 45 GPa (6.5 x 106 psi) RT tensile atrength/elangation: 318 MPa (46 bsi)/l2% RT yield strength: 142 M h (20 hi) Test temperature: Room temperalure Test environment: 3.5% salt water solution Failure criterion: 20% load drop or fracture Loading condition: Strain control, axial R = -1.0, and -2 Specimen geometry: Uniform gage section, 6.35 mm

Surface: Machined, longitudinal polish Gauge length: 13 mm (‘/2 in.) F‘requency: 0.5,1, and 2 Hz Strain rate: 0.004 to 0.026 s-I Testspecbtions: 12-hpresoak Source: C.D. Schrader, *‘Corrosion Fatigue and Stress Corro-

(0.025 in.)

sion Cracking of AZ291ET6 Sand Cast Magnesium Al- loy,’’ Master’s thesis, The University of Iowa, Dec 1992

il0*i w . c . 5 . 5 .

1 o9 I

. . . . . . ..I . . . . . . . ., . . . . . . .., . . . . . . ..I . . . 10 102 109 104 106 10a

Reversals to failure, 24 Fig. 9 AZ91 ET6: Low-cycle fatigue in salt-watw solution

Composition: 8.97AI-0.54Zn-0.17Mn-0.010Cu-0.01 Si- 0.003Fe-0.0010Ni

Product form: Sand cast Heat treatment: T6 Modulus of elasticity (avg at RT): 45 G h (6.5 x 106psi) RT tenslle cltmgth/elongation: 3 18 M h (46 ksi)/12% RT yiela strength: 142 MPa (20 ksi)

Test environment: 3.5% salt water solution Loading condition: Load control, R = 0.5 and 0.05 Specimen geometry: Compact type S U M Polished Frequency: 3 Hz. Haversinc Soum: C.D. Schrader, “Corrosion Fatinue and S a s s Corro-

Test tempetatum 23 “C (74 “p)

* .-A

1 10 AK, MPa Jm

don Cracking of AZ291E-T6 Sand East Magnesium Al- loy,” Master’s thesis, The University of Iowa, Dcc 1992

Fig. 10 AZ91E Fatigue crack growth behavior in salt water solution


Cornpsition: 9.OAl-O.lOMn-2.0Zn-bd Mg Product form: Sand cast Heat treatment: F, T4, T6 Modulus of elasticity (avg at RT): 45 GPa (6.5 x lo6 psi) RT tensile strengthlelongation: F 165 MPa (24 ksi)/2%

T4: 275 MPa (40 ksi)/9% T6: 275 MPa (40 ksi)/2%

RT yield strength: F: 95 MPa (1 3 ksi) T4: 95 MPa (1 3 ksi) T6: 145 MPa (21 ksi)

Tabb 5 -A: Fatiwe of sand castinas

Test temperature: 25 ‘C (77 OF) Test environment: Air Failure criterion: Fracture Loading condition: Krouse plate bending, axial Surface: Machined and polished Source: ‘Tables of Fatigue Strength of Sand Cast Magne-

sium Alloys,” Dow Chemical Co,, TS&D Letter Enclo- sure, 19 Nov 1965

P 90 13 75 11 65 9 165 24 160 n 1u) 21 T4 105 15 85 12 60 8 235 34 21s 31 205 29 76 125 18 100 14 90 13 210 30 1% 26 190 27

Compwitiion: 9.0A1-0.2~-2,0Zn-bal Mg Product form: sand Cast Heat treatment: F, T4, T6 Modulus of elasticity ( a q at RT): 45 GPa (6.5 x 1 0 6 psi) RT tensile stren@/ebngation: F 165 MPa (24 ksi)/2%

T4: 275 MPa (40 ksiP% T6: 275 MPa (40 ksi)D%

RT yield strength: F: 95 MPa (1 3 ksi)

Test temperature: Room temprature

T4: 95 MPa (1 3 ksi) T6: 145 MF’a (21 ksi)

Test environment: Air Failure criterion: Fracture Loadfng condition: Rotating beam, R = -1 Specimen geometry: Some specimens notched Surface: Smooth, machined, and polished, also notched Test sped’htions: R = -1 Source: ‘Tables of Fatigue Strength of Sand Cast Magne-

sium Alloys,” Dow Chemical Co., TS&D Letter Enclo- sure. 19 Nov 1965

hbk 6 AZ92A Fatigue of notched mnd carttngs

Rurue tlrmrth at:

F 115 16.5 105 15 95 13.5 90 13 85 12 80 11.5 55 8 ..) ... .( I ... T4 125 18 110 16 105 I5 95 13.5 90 13 100 14 75 1 1 55 8 40 6 T6 130 19 115 16.5 100 14 95 13.5 85 12 80 11.5 60 8.5 40 6 30 4

A#lB(UNS Y11311)/157

Composition: 3.OA10.20Mn-1 .OZn-bal Mg product form: Extrusion Heat treatment: F Modulus of elmticity (avg at RT): 444 GPa (6.5 x 106 psi) RT tensik strength/elongation: 260 MPa (37.7 ksi)/15% RT yield strength: 200 MPa (29 ksi) Test temperaturn: Room temperature Test environment: Air

Failure criterion: Fracture Lopding condition: Rotating beam (R = -1). plate bending

SurPace: Polished, etched Source: “Magnesium in Design,” Bulletin 141-213, Dow

(R = -1), axial load (R 0.25)

Chemical Company, 1%7; R.S. Busk, Mugnesium P d - WIS Design, Marccl Dekker, New York, 1987, p 352

Composition: 3.OA1-0.20Mn-1 .OZn-bal M g Product form: Plate Heat treatment: H24 Modulus ofelastidty (avg at RT): 44.8 GPa (6.5 x lo6 psi) RT h s i l e strength/elongat&n: 270 MPa (39.1 ksi)/l9% RT yield strength: 185 MPa (26.8 hi)

Test environment: AU FaUure criteri6n: Fracture h d i n g condition: Cantilever bending, R = -1,0 Source: RS, Busk, Magnesium Products Design, Marcel

Test temperature: Room temperature ll

Dekker, New York, 1987, p 452

104 lo6 Id 1 07 lOe - 1 Cantilever bending fatigue of AWlB-H%plate

Composition: 3.OAl-O.2OMn-1 .OZn-bal h4g M a c t h: sheet Heat treatment: H24 Modulus of ehstidty (avg at RT): 44.8 GPa (6.5 x 106 psi) RT tenrIte streogthlelongation: 290 MPa (42 ksi)/l5% RT yield streqth: 220 MPa (3 1.9 ksi)

Terrtenvironment:Air Failure criterion: Fracture Loading condition: Cantilever bending, R = -1 Surface: Anodic cuated Source: S.J. Ketcham, “Investigation of Anodic Coatings for

Magnesium Alloys,” Report No. NAMC4ML-1347, Amnautical Materials Laboratory, Naval Materials Cen- ter, Philadelphia, PA, 10 Jan 1962; R.S. Busk, Magnesium Products Design, Marcel Dekker, New York, 1987, p 449

Teat temperature: Room temperature 3

lo4 10s id 108 Cyclw

Flg.2 BendingfatigueofAZ31B-H24sheet

158 I Magnesium Alloy Fatigue Data

Composition: 3.OA1-0.20Mn-1 .OZn-bal Mg Product form: Forged Heat treatment: F Modulus of elasticity (avg at RT): 44.8 GPa (6.5 x lo6 psi) RT tensile strength/elongation: 260 MPa (37.7 ksi)/9% RT yield strength: 195 MPa (28.2 ksi) Test temperature: Room temperature Test environment: Air Failure criterion: Fracture Loading condition: Strain control (R = -1) Surface: Smooth Source: S.S. Manson, Fatigue: A Complex Subject-Some

Simple Approximations, Exp. Mech., July 1965 1041 . . . . . . . . I . . ......I . . ......I . . . .... d . . ....._I . . . Y

1 10 102 lo3 10' lo5 lo8 Cyclic life

Fig. 3 Strain-life diagram for AZ31 B

Composition: 3.OA1-0.20Mn-1 .OZn-bal Mg Product form: Extrusion Heat treatment: F Modulus of elasticity (avg at RT): 44.8 GPa (6.5 x lo6 psi) RT tensile strength/elonption: 260 MPa (37.7 ksi)/15% RT yield strength: 200 MPa (29 ksi) Test temperature: Room temperature

Test environment: Desiccator, water immersion, condensed water in air and various substances

Failure criterion: Fracture Loading condition: Axial load, R = 0.25 Surface: Smooth Source: Dow Chemical Company, unpublished; R.S. Busk,

Magnesium Products Design, Marcel Dekker, New York, 1987, p 356

Table 2 Effect of corrosion on fatigue properties of AM1 B (Axial load; R = 0.25)

Fatigue limit at CWL: MPa kSi

Alloy AtmosDhoetest l@ 106 101 105 106 101

Fatlgw Limfts AZ31B-F Desiccator 195 170 I65 28 25 24

Water immersion 145 145 ... 21 21 Condensed water in air 130 90 85 19 13 12

LikofAZjlBFatawnstsntstRsaof140MPp(20~) A t m w D h o f taSt Cycles to Bilure

Condensed water in: Desiccator >loS

Air 6 x l@

Nitrogen 6 x 105 Oxygen 3.5 x 105

Argon 2 x 106 Argon + C02 105 Argon + SO2 105

Air + ammonia 5x105 Air +ammonia + SO2 105

Argon +ammonia 5x105

AZ31 B, Fatigue Crack Growth / 1 9

Composition: 3.OA1-0.20Mn- 1 .OZn-bal Mg Product form: 0.5 in. plate Heat treatment: H24 Modulus of elasticity (avg at RT): 44.8 GPa (6.5 x lo6 psi) RT tensile strengtWelongat&n: 250 MPa (36.2 ksi)/21% RTyMdstrength: lSOMPa(21.7 hi) Test temperature: Room temperature Test environment: Laboratory air Loading condition: Load control, R = 0.1,0.4,0.7 Specimen orlentation: T-L Specimen geometry: C (T) 0.5 in. thick Frequency: 5-50 Hz

0

0

A R=0.100 R-0.400 Rr0.700 Source: R.G. Forman, unpublished data

1

1

F&. 4 WdN data f o r m 1 B magnesium (H24)

Composition: 6.SAl-0.1 SMn-1.OZn-bal Mg Product form: Pancake forging Heat treatment: F Modulus of elasticity (avg at RT): 44.8 GPa (6.5 x 106 psi) RTteaelle strengtl@ongetion: 195 MPa (28.2 ksi)/% RTyield strength: 180 MPa (26.1 ksi) Test temperature: Room temperature Test environment: Air

Table 3 Fatipus stnngth of A261 Atoglnna

Failure criterion: Fracture Loading condition: Rotating beam (R = -l),

Spedmen orientation: Longitudinal Surlsce: Polished, as forged Source: “Magnesiumin Design,”BuUetin 141-213, Dow

Flexure (R = -1)

Chemical Company, 1%7; R.S. Busk, Magnesium Ptvd- ucrs Design, Marcel Dekker, New York, 1987, p 489

Fatipe QtRgLMps)otmlw AUoy ’Rmm FWlM Orlentation twl sumce 10s 106 107 lo, AZ61A F Pancalrc Longitudinal Rcmingkam P o l i 180 150 14s 140

Fkxun A$.!iXgd 110 0s IS I,.

Composition: 6.5A1-0.15Mn-1 .OZn-bal Mg M u c t form: Extrusion Heat treatment: F Modulus of elasticity (avg at RT): 44.8 GPa (6.5 x lo6 psi) RT tensile strengthlelongation: 3 I0 MPa (44.9 ksi)/l6% RT yield strength: 230 MPa (33.3 ksi) Test temperature: Room temperature Test environment: Air Failure criterion: Fracture

Table 4 Fatigue strenath of A261 A-f extrusions

Loading condition: Rotating beam (R = -l), plate bending

Specimen geometry: Some notched (K1 = 2.0) Surface: Polished, extruded Source: “Magnesium in Design,” Bulletin 141-213, Jhw

(R = -l), Axial (R = 0.25)

Chemical Company, 1967; R.S. Busk, Magnesium P d - ucts Design, Marcel Dekker, New York, 1987, p 352

sur(Sce0r Fatigue limit (&Pa) at cycles: 5 p e of test R value stm concmtrstion 10s 106 107 s x 107 108 RMatingteam -1 Polishal 185 I70 15s ... I 4 0

K t = 2 .,* ... ... 130 ... pkte bending 1 Extruded 125 95 85 *.. ... Axial load 0.25 polished 170 1-40 130 ... ...


100.

Composition: 6.5AI-0.15Mn-1 ,OZn-bal Mg Product form: Bar Heat treatment: F Modulus of elasticity (avg at RT): 44.8 G h (6.5 x lo6 psi) RT tensile 8trength/eiongation: 3 10 MPa (44.9 ksi)/l6% R T y b l d s t m g t h : 230MPa(33.3 ksi) W t temperature: Room temperature Test envkronment: Air Failure criterion: Fracture Loading condition: Rotating bend, R = -1 .O Surface: Smooth Source: Metallic Materials and Elements for Flight Vehicle

Structures, MIL-HDBKJ. Department of Defense, Aug 1%2; Aerospace Structural Metals Handbook, Battelle Metals and Ceramics Information Center, Columbus, OH, 1991,code3603,p7

Mg4AI-1 Zn . O Runout Upper and lower range _ . _

Fig. 5 S-N curves for ,426 1A bar

Composition: 6SA1-0.15Mn-1 .OZn-bal Mg Product form: Plate Heat treatment: F Modulus of elasticity (avg at RT): 44.8 GPa (6.5 x lo6 psi) RT tensile strength/elongation: 3 10 MPa (44.9 ksi)/l6% RT yield strength 230 MPa (33.3 ksi) Test temperature: Room temperature Test environment: Air Failure criterion: Fracture Loading condition: Rotating bend, R = -1 -0 Surface: Smooth Source: Metallic Materials and Elements for Flight Vehicle

Structures, MIL-HDBK-5, Depamnent of Defense, Aug 1%2: Aerospace Structural Metals Handbook, Battelle Metals and Ceramics Information Center, Columbus, OH, 1991, code 3603, p 7

AZ6lA

10‘ 106 10’ 10’ CSkS

Fig.6 S-NcurvesforAZ61Aplate

Composition: 8.5A1-0.12Mn-O.5Zn-bal Mg Product form: Extrusion Heat treatment: F Modulus of elasticity (avg at RT): 44.8 GPa (6.5 x 106 psi) RT tensile strengWdongatbn: 340 MPa (49.3 ksi)/ll% RT yield strength: 250 MPa (36.2 ksi) Test temperature: Room temperature Test envlronment: Air

Failure criterion: Fracture Loading condition: Rotating beam (R = -1) and plate bend-

Surface: Polished, extruded Source: “Magnesium in Design,” Bulletin 141-213, Dow

ing (R = 0.25)

Chemical Company, 1967; RS. Busk, Magnesium Prod- ucfs Design, Marcel Dekker, New York, 1987, p 352

Table 5 Fatigue strength of AZ8OA.F emr lons

Surface or Fatime limit WPa) at cycks: Alloy are of teat R d W stma comtmtlon I@ 106 107 Id AZSOA-F Relating beam - I Polished 190 175 160 150

m - g 0.25 Extruded 140 100 90 ...

AZBOA (F, T4, T5, and T6 Tempers) / 181

Composftion: 8.5A1-0.12Mn-0.5Zn-bal Mg product form: Extrusions and forgings Heat treatment: F, T4, T5, T6 Modulus of elasticity (avg at RT): 44.8 GPa (6.5 x 106 psi) RT tensile strength/elongation: Extrusion F: 340 MPa

(49.3 ksi)/l 1 %; Forging: F 3 15 MPa (45.6 ksi)/8%; T5: 345 MPa (50 ksi)/6%; T6: 345 MPa (50 ksi)/5%

RT yield strength: Extrusion F 250 MPa (36,2 ksi); Forg- ing: F 215 MPa (3 1.1 ksi); T5: 235 MPa (34 ksi); T6: 250 MPa (36.2 ksi)

’kt temperature: Room temperature Test mvinmment: Air Failure criterion: Fracture Loading condition: Rotating beam (R =-I) , reversed bend-

Surface: Smooth, as extruded and as forged Source: “Strength of Metal Aircraft Elements,” ANCJ,

ing (R = -1)

March 1955; Aerospace Structuml Metals Handbook, Battelle Metals and Ceramics Information Cen!er, Co- lumbus, OH, 1991, code 3501, p 2

Table 6 Fatigue strength of AZBOA

Conditbn ’Itmpnrtum Stmweonccatntkn 105 C Y C k 106 mks 10’cycL lo8 C W L Fatlguestrengtb kai, rt:

25-30 23-28 21-26 20.24 28-30 24-26 20.22 18-20

I , < 21-24 18-21 1618 26.30 22-25 19-21 1619 23-21 19-22 16-19 1416

mlanperaaua Asatrmded 19-21 13-16 12-14 -oempascum &.Forged 16.20 13-16 12-15

1 1 1

. . I

Composition: 8.5A1-0.12Mn-O.5Zn-bal Mg Product form: Extrusions and forgings Heat treatment: T5 Modulus of elasticity (avg at RT): 448 GPa (6.5 x 106psi) RTtensile stren%hjelongatlon: Exhusion: 340 MPa (49.3

ksi)/lI%; Forging: 345 MPa (50 ksi)l6% RT ykld strength: Extrusion: 250 MPa (36.2 ksi); Forging:

235 MPa (34 ksi) Test temperature: Rmm temperature and150 O C (300 OF) Test environment: Air

Table 7 Fatlgue strength of notched AZBOA

Failure criterion: Fracture Loading condition: Reversed bending (R = -l), d n g

beam (R = -1) Specimen geometry: Some notched, Kt = 2 Surface: Smooth Source: Ordnance Materials Handbook, Magnesium and

Magnesium Alloys, ORDP 20-303, Sept 1956; Baaelle Metals and Ceramics Information Center, Columbus, OH, 1991, code 3501, p 2

R e ~ d bendi, R - -1 T5W Room t e m p e m Smooth, Kl = 1 20

Smocnh 25 Notched, 4- 2 16.5 Smooih 20.5 Notdred, Kl = 2 10.5

12.5 ...

20 9 5

11 6.5

18 9.5

105 5

162 / Magnesium Alloy Fatlgue Data

Composition: 8.5A1-0.12Mn-OSZn-bd Mg Product form: Extrusion (longitudinal) Modulus ofelastkity (avg at RT): 44.8 GPa (6.5 x 186 psi) RT tensile strength/elongation: 372 MPa (53.9 ksi) RT yield strength: 284 MPa (41.2 ksi) %st temperature: Room temperature Test envhnment: Air Failure criterion: Fracture Loading condition: Reverscd bending (R = -1) Specimen orientation: Longitudinal Notch geometry: 60", 0.025 in. deep, 0,010 in. radius Surface: Polished Frequency: 90,2000,3450 cpm Source: T,T. Oberg and W.J. Trapp, High Stress Fatigue of

Aluminum and Magnesium Alloys, P d . Eng., Vol22 (No.2),Feb 1951,p 163 cpcr

Fig, 7 High stress fatigue of AZ80msgnesiurn alloy

Composition: 8SA1-0.12Mn-OSZn-bal Mg Product form: Extrusion (longitudinal)

RTtensile strengthlelongatbn: 372 MPa (53.9 ksi) RT yield strength: 284 MPa (41.2 ksi) Test temperature: Room temperature

Failure criterion: Fracture Loading condition: Axial (R = 0 and -1) Specimen orlentation: Longitudinal Specimen geometry: a", 0.025 in. deep, 0.010 in. radius surppce: Polished Frequency: 90,2000,3450 cpm Source: T.T. Obetg and W.J. Trapp, High Stress Fatigue of

Aluminum and Magnesium Alloys, Prod, Eng., Vol22

G-R-0 Modult~ of elasticity (avg at RT): 443 GPa (6.5 x 106psi) A D , n d h . d R - - l

i Test environment: Air B 1

(No. 2), Feb 195 I , p 163 w- Fig. 8 High S ~ S B fatigue of Az80 magnesium alloy

Composition: 7.5Al-O. 13Mn-0.7Zn-bal Mg Rwiuct form: Pancake forging Heat treatment: F, T5, T6 Modulus of elasticity (avg at RT): 44.8 GPa (6.5 x lo6 psi) Test temperature: Roomtemperature Test environment: Air Faflure criterion: Fracture

Tabb8 Fatiwoof AZBlAtorninas

Losding condition: Rotating beam (R 5i -1) and flexure

Specimen orientation: Longitudinal Specimen geometry: Pancake SurEace: Polished, as-forged Remarks: mically classifie4 BS a casting alloy Source: "Magnesium in Design," Bulletin 141-213, Dow

(R=-1)

C h d c a l Company, 1967

Fatigue stm!um (Mp.) rt mk: Albr k w r Forcing OrkcaMbn te3t sum Id 106 107 10s

AZ81A F h a k e LongirudinaJ R w i n g Polished 2ai im 145 130 TS kpm 195 160 140 125

170 140 125 105 T6 Flexure A6-f- 12s 9s 95 * I .

ZE41A Casting Alloy (UNS M16410) / 163

Modulus of elasticity (avg at RT): 44.8 GPa (6.5 x 106 psi)

RT yield strength: 180 MPa (26.1 ksi) RT tensile strength/elongation: T6: 275 MPa (39.8 ksi)/5% -

MgZn Alloys

10

Composition: 3.5-5.0Zn.O.75-1.75 R.E.,0.4-1.0Zr,0.10 Cu (mu), 0.01 Ni (ma), 0.30 other (max), bal Mg

Product form: Sand casting Beat treatment: T5 Modulus of elasticity (avg at RT): 44.8 GPa (6.5 x 106 psi) RT tensile strength/elonption: 200 MPa (29 ksiY2.58 RTyield strength: 134 MPa (19.5 ksi) Test temperature: Room temperature Test environment: Air Failure criterion: Fracture Loading condition: Rotating beam, R = -1 Specimen geometry: Some notched, U-notch, Kt = 2.0 Surface: Smooth, machined, and polished Frequency: 2,960 cpm Source: M.J. Miles, ‘23241: AMagnesium Alloy with Im- 1 o4 I 06 107 I o*

proved Mechanical Properties for Use in Helicopter Cycle5

Transmission Castings,” American Helicopter Society, May 1977 Fig. 1 Fatigue properties of ZE41A, notched and unnotched

Failure criterion: Fracture Loading condition: Rotating beam (R = -1) Specimen geometry: Some notched, Kt = 2 Surface: Smooth - Source: J.W. Meier, Characteristics of High-Strength Magne-

- CondMon T6 ?c - - - . J W - - *

siumCastingAlloyZK61, Truns.AFS, Vo161,1953,p R - - 1 - 5o

12

m i 0


Composition: 1.8Th-5.7Zn-0.7Zr-bal Mg Product form: Sand cast Heat treatment: T5 Modulus of elasticity (avg at RT): 44.8 GPa (6.5 x lo6 psi) RT tensile strength/elongation: 275 MPa (39.8 ksi)/6% RT yield strength: 170 MPa (24.6 ksi) Test temperature: Room temperature Test environment: Air

Failure criterion: Fracture Loading condition: Krouse plate bending (R = -1) Surface: Machined and polished Source: ‘Tables of Fatigue Strength of Sand Cast Magne-

sium Alloys,” Dow Chemical Co., TS&D Letter Enclo- sure, 19 Nov 1965; “Mechanical Properties and Chemi- cal Compositions of Cast Magnesium Alloys,” Bulletin 440, Magnesium Elektron Ltd., March 1981

Table 1 ZH62A and ZK61A fatlgue strength compllatlon

A b Y Form and and Test stmi9 Fatieue strength, MPD (W, at mka:

ZK61A-T6 Sandcast Machinedandpolished, Krouseplate -1 Roomtemperature Atr ... 585(85) 415(60) 345(50) ... W62A-TS Sand cast Machined and polished, Krouse plate -1 Roomtemperature Air ... 860(125) 585(85) 517(7S) ... W62A-TS Sand cast Mechined and polished, Rotating beam -1 Room temperature Air ... 825(120) 585(85) 570(83) 565(82)

W62A-TS Sand cast Machined and polished, Rotating beam -1 Room temperature Air ... ... 550(80) ... 525(76)

temper thickma Specimen mode Rtb h p e r P t u R AtmWDheR IV 106 10’ 5x107

unnotched bending

unnotched bending

unnotched

notched Kt = 1.8

Sources: TSDLstter, Nov 1966, and Magnesium Elektmn Bulletin 440,1981

Composition: 0.17 Rare Earths-1.2Zn-bal Mg Product form: Sheet Heat treatment: F Modulus of elasticity (avg at RT): 44.8 GPa (6.5 x lo6 psi) RT tensile strength(e1ongation: 260 MPa (37.7 ksi)/lO% RT yield strength: 170 MPa (24.6 ksi) Test temperature: Room temperature Test environment: Air Failure criterion: Fracture h d i n g condition: Axial load, R = 0,0.5 Surface: Smooth Source: “ZElOASheet & Plate Magnesium Alloy,”TS&D

Letter Enclosure,“ Dow Chemical Co., 1 June 1984 501 . . . . . ...I . . . . . . . I . . . . . ... I . . . . . J0 1 o4 1 06 1 06 10’ 108

Cycles

Fig. 3 Fatigue of ZElOA sheet

Composition: 5.5Zn-0.5Zr-bal Mg Produd form: Extrusion Heat treatment: F, T5 Modulus of elestidty (avg at RT): 44.8 OPa (6.5 x 106 psi) RTtensile sdrengthtelongatbn: F 340 Mpa (49.3 ksi)/14%;

T5: 365 MPa (52.9 ksi)/ll% RT ylela strength: F: 260 MPa (37.7 ksi);

T5: 305 MPa (44.2 ksi) %st temperature: Room temperatun ’Itst environment: Air Fpnure criterion: Fracture Loading condition: Rotating bcam ( R = -I), axial load (R =

Specimen orieatation: Longitudinal SurEece: Machined and polished Swrce: “Magnesium in Design,” FormNo. 141-213-67,

0.25)

DOW Chemical CO., Metal P d ~ c t s D q t , 1967; Acm- space Structural MateriaLs Handbook, Banelle Metals and Ceramics Infonnation Center, Columbus, OH, 1991, code 3506, p 1 1

250

ld . . . . . . . . 1 . . . . . . . . I . . . . . . .d15 Id 1 06 107 108

Fig. 4 ZK6oA (P temper): rotating beem fatigue (R = -1)

$4 . . . . . . . . I . . . . . . . . 1 . . . . ..A15 Id Id 1 o7 id

cvclee Fig, 5 ZK6oA (”5 temper): rotating beam fatigue (R = -1)

lo6 lOe cvdea

Flp. 7 ZK6OA (T5 temper) extrusions: axial fatigue (R = 0.25)

166 / Magnerlum Alloy htlgue Data

m Z W A

Composition: 5.5Zn-0SZr-bal Mg Roduct form: Forging Heat treatment: TS Modulus of elastidty (avg at RT): 44.8 GPa (6.5 x 1 0 6 psi) RT te~sile strength/elongation: 305 M h (44.2 ksi)/l6% RT yield strength: 205 MPa (29.7 ksi) Test temperature: Room temperature Test environment: Air Failure criterion: Fracture Logding condition: Rotating beam, flexure, R = -1 Spedmen geometry: Some notched, Kt = 2 Surface: Machined and polished Source: H.C. Buckelew, Magnesium Alloy Cuts Aircraft

Wheel Cost, Weight, SAE J . , Vol72, April 1964, p 90-94; Aerospace Srructuml Materials Handbook, Battelle Met- als and Ceramics Infomtion Center, Columbus, OH, 1991,code3506,p 1 1

Rotating beam

50

! lo6 l@ 10’ Id

WIM Fig. 8a Rotadating beam fatigue strength of WC60A-TS forgings

- 10 L 8

Machined specimen scatter E; C y e b

Fig. 8b Flexure fatigue of ZK60A-TS forgings

Composition: 5.5Zn-0.4Zr-bal Mg Product form: Forging-wheel rim Heat tmatment: TS, T6 Modulus of elasticity (avg at RT): 44.8 GPa (6.5 x 106 psi) RTtensile strength/elongation: 305 MPa (44.2 ksiY1696 RT #Id strenw 205 MPa (29.7 hi) Test temperature: Room temperature Test environment: Air Failure criterion: Fracture

Table 2 Fatigue strength of forged ZKBOA wheel dm8

Loading condition: Rotating beam and flexure Specimen orientation: Tangential and axial Specimen geometry: Wheel rim SurPace: Polished Source: “Magnesium ZK60A-T6 Forging Alloy,” TS&D

Letter Enclosure,” Dow Chemical Co.; R.S. Busk, Mag- nesium Products Design, Marcel Dekket, New York, 1987, p 490

Fstiguc Mp.. at cwk: Alby P m w Forldng OricPtatbn -1 Sulfea? 101 106 107 lfP ZK60.4 n whcelrim lkngential Rotatingbeem Polished 160 140 125 125

Axial Polished 160 140 125 125 N a W ) 95 85 m 60

Axial Flexun(a) Polished 130 95 90 85 T6 Wheelrim Tsngenlial Rotatingbeam Polished 185 150 130 115

Axial Polished 185 1 so I 3 0 115 Notched@) 115 90 70 60

Axid F!exure(a) Polished 140 125 110 105

( a m =-1. (b)& 2

Z K W (UNS M166UO) Plate, Fatigue Crack Qrowth / 167

Compositbn: 5.5Zn-0.4Zr-bal Mg Product brm: 0.5 in. (12.7 mm) plate Heat treatment: T5 Modulus of elasticity (avg at RT): 44.8 GPa (6.5 x lo6 psi) RT ten& strength/elongatkn: 305 MPa (44.2 ksi)/16% RT yield strength: 205 MPa (29.7 ksi) Test temperaturn Room temperatun ' k t environment: Laboratory air Loading condition: Load control, R = 0.1,0.4,0.7 Speelmen orientation: T-L Specimen geometry: C g , 0.5 in. (12.7 mm) thick

Source: R.G. Forman, unpublished data W U ~ C ~ : 5-50 Hz

lbbk3 R=O.l bta

number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27

29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49

28

so

drrldh: u, I&*

0.1974- 0.257884 02844E-w 0.41 l 9 W 0.4oOsE-W 0.4874E-04 0.7328E-M 0.86SOE-CM 0.1398EXG 0.19Oom 02642E03 0.3274Eco3 0.4365E-03 0.7291E-03 0.17478.03 0,2882ti-03 0.3487E-W OA102E-03 0.9857E-03 0.W3E-03 0.1736E-M 0.42088-02 OA729M1 0.2260E-06

0- 05740E-06 0.7830E-06 0.1309E-05 0.1884m 0.2549B45 0.3097E-05 0.3982E-W 0.484oE;05 0.6o6oE-05 0.7601EO5 O.l9OoE.(n 0.6200E47 0.1030Ed6 O.u)10&06 0.2WE-06 0.2 I sow 0.2390E-06 0314oE-06 0372oE-M 0.497OE-06 0.6woE-06 0.9250&06 0.1992E-05 0,3752845

0.2870~-06

kSIK 8.070 8.530 9.030 9.570

10.190 l0.8#, 11.600 12.430 13.360

15.030 15.650 16.330 16.800 15.970 16.660 17.540 18.530 19.460 2 a 4 S 21.610 22790 40.430 2.390 2.500 2.680 2.800 3.010 3.220 3.410 3.660 3,890 4.090 4.420 4.780 5.110 1.260 1.330

1.460 1.550 1,660 1.760 1.760 1.954 2.180 24 10 2.740 3 . m 4.080

14.420

1.310

lo{ mpcpu 10

A

o * A A

1 10 bnwdn.

F@ 9 d d d N data for ZK60A-T5

Table4 R=0.4data

sample number I 0.162ow 1.140 2 0.2080346 1200 3 0.2630w 1.250

5 0.28fo&06 1.380 6 0.4Xx)6-06 1.m 7 0.10978-03 1.980 8 0.11WEM 2.w 9 0.1485E05 17%0

3510 11 12 O p $ 7 0 7 E M 4.160 13 0.6056M# 10.690 14 0.7624B-W 11.420 15 0.88308-04 11.930 16 0.8009W 12.520 17 0.16623-03 13,150 18 0.25 IOW 13.840 19 0.2089EM 14.600 20 03535E-03 15A40 21 0.2109G02 16.810 22 0.8108E.05 4.400 23 0.7317B-05 4.620 24 0.8634B-05 4.750 25 0.965 1 Ea5 4.960 24 0.9932505 5560 27 0.1150E-04 5 m

u% w, InJcvek

4 0.301oM)6 1.3m

10 0.3476E-05 3.120 OA065E05


Table 5 R = 0.7 data

Sample Qldhs M, number in/cwle kSiK 1 0.2070E-06 0.930 2 0.23OOE-06 0.990 3 0.23H)E-06 1.040 4 0.27OOE06 1.090 5 0.3230E06 1.190 6 0.3010E-06 1.300 7 0.52OOE-06 1.420 8 0.4620&06 1.580 9 0.6080E-06 1.760 10 0.67OOE-06 1.970 11 0.8520E-06 2.220 12 0.15833-05 2.540 13 0.2455B05 2.920 14 0.36 13E-05 3.390 15 0.1 1278-04 5.460 16 0.11988-04 5.740 17 0.1175E-04 6.000 18 0,14128-04 6.310 19 0.1346E-04 6.620 20 0.1609E-04 6.980 21 0.28 16E04 7.370 22 0.2816E04 7.370 23 0.22578-04 7.870 24 0.27OOEO4 8.250 25 0.3560E-04 8.740 26 0.6002E-04 9.640 27 0.1565E05 2.640 28 0.2 5 69 M 5 2.770 29 0.2413M5 2,910 30 0.32 13E-05 3.010 31 0.3043M5 3.220 32 0.3726E-05 3.450 33 0.3975E-05 3.520 34 0.4725E05 3.770 35 0.49098-05 3.950 36 0.6441E-05 4.120 37 0.65 13E05 4.600 38 0.9299E-05 4.830 39 0.970SE-05 5.330 40 0.1357E-04 5.560 41 0.1862E-04 5.880 42 0.3760E-04 7.290 43 0.6330E-04 7.800 44 0.2770E-01 10.250

Composition: 5.5Zn-0.4Zr-bal Mg Product form: Extrusion Heat treatment: T5 Modulus of elasticity (avg at RT): 44.8 GPa (6.5 x lo6 psi) RT tensile strengtwelongation: 365 MPa (52.9 ksi)/16% RT yield strength: 305 MPa (44.2 ksi) Test temperature: Room temperature Test environment: Distilled water and dry argon Loading condition: Load control, R = 0 Specimen orientation: S-T Specimen geometry: M C O Frequency: 4 Hz Source: E.U. Lee, “Corrosion Fatigue and Stress Corrosion

Cracking of 7475-T735 1 Aluminum Alloy,“ Corrosion Cracking, Int. Cant Expos. Fatigue, Corrosion Crack- ing, Fracture Mechanics, and Failure Analysis, V.S. G~l,Ekt. , 1 9 8 5 , ~ 123-128

1 10 aK bd 4in

Fig. 10 d a / f l data for ZK60A magnesium

ZKBOA Extrusion, fatigue Crack Qrowth In Water / 169

Table 6 Dry argon data, R r 0

h p l s QiW number I 0.3365E-04 9.806 2 0.3826E-04 10.340 3 0.42408-04 10.764 4 0.46946-04 11.032 5 0.5336E-w 11.511 6 OWW 12256 7 0.7445E-04 12737 8 082slE04 13.163 9 0.98616-04 13.641 10 0.1 1223.03 14.228 I1 0.1278E-03 15.083 12 0.1649E-03 15.828 13 0.2133E-03 16948 14 0.2490EU3 17.695 15 0.27636.03 18.283 16 0.339oe-03 18.975 17 0.3%2503 19.883 18 0.6639E-03 22.392 19 0.7555E03 23.032 20 0.8582Eo3 23.404 21 0.9046E-03 23.832

k$?k Table 7 Dlstllkd water d m , R 3 0

ample QW number 1 0.1579E-07 1.114 2 0.60ME07 1.129 3 0.1423E-06 1.105 4 0.1058E-05 2.335 5 03121E-05 3.485 6 0.4017E-05 3.908 7 0.1163E-04 6.025 8 O,1390M)4 6.654 9 0,1579E-04 7.036 10 0.1748E04 7355 11 0.2037E04 7.834 12 0.23 14E-04 8.106 13 0 . n 6 7 m 8.845 14 0.3947E-04 9.694 I5 0.4264&04 10.068 16 0.46056-04 10388 17 0.5101E-04 10.760 18 0.55098-04 11.080

20 0.8700W 12.248 21 0.1015E43 12.9% 22 0.1411BM 13.6xl

24 02228E-03 14.798 25 0.2667E-03 15.599 26 03268W3 16.130 n 0 . 4 3 m m 16.820 28 0.1465BM 20.328 29 0.2167BM 22.135

&

19 O.RglEr04 11.m

23 0.1865E-03 14320


Mg-Th Alloys

Table 1 Yagnesium-thorlum alloys: Mircelhneour fMlgue strength data

A l k y d Faanand Wt -B Tkm#rrturP P a t b e stmath , MR W), at cwhs oli tempa thklums Soeelmen mode Rtb A OCPF) A h n o J l ~ h lo' lo' 10 5x10 1 HK31A-T6 S a o d a t MWhinedmd Krou~eplate -1 25 (75) Air ,.. 125(18) 75(10.8) 60(8.7) ,,. I , ,

Sandcast Machinedand Krolwplate -1 200(390) Air ,,. lW(14.5) SS(8) 5Ofl.25) ... ,..

SandEast Mschinedand Krourplate -I 315(Mx)) Air .,. a(8.7) 45(6.5) 35 (5) 1 1 1 ...

polished bending

polished bending

poliskd bending HM31A-TS Extrusion Polished W n g beem - I RT Air ... 125(18) lOS(l5) 90(13) .,. 95(13.7)

Extrusion Notched, Roteling beam -1 RT Air ,,, 90(13) 55(8) 45(6.5) .., K i d 0

HZ32A-T5 Sandcasi U n n m k d , Rotstingbeam - I RT Air ,.. 105(15.2) W(13) 75(10.8) 70(10) 70(10) machined and @MwJ

Sandcast Notched,Kf2 R o t a t i n g h -1 RT Air ... .., M(8.7) ,,. 60(8.7) .., Sandcart Notched, Ktp5 Rotatingbeam -1 RT Air . I . ... 40(5.8) ... I , . M(4.35)

Swrcea: Dow chemical and MagneEiurn E l e h

Composition 3.2Th-0.7Zr-bal Mg M u c t form Sheet Heat treatment H24 Modulus of elasticity (avg at RT) 44.8 G h (6.5 x 106psi) RT t e d e strength/elonptlon 255 MPa (36.9 ksi)/lO% RT yield strength 205 MPa (29.7 hi) Teat temperature Room tempesature, 149 "C (300 OF), 260

Test environment Air Failure criterion Fracture hading condition Axial loading (R = 0.33, and 0.01) Spedmen geometry Notched, Kt = 3., 5 Surface Smooth Source A.A. Blatchenvich and A.E. Cm, 'Fatigue, Creep,

"C (500 "€7)

and Stnss Rupture of Several Supdloys," AFMLTech- Neal Report69-12, Jan 1969

1 , , , . . . , . I , . . . , , , , I , . . . . . , , I . . . , . . ovpb

Fig. 1 Room temperature and axial fatigue of HK31A

1 , . . . . . . , I . . . . . , , , I . . . , , , . . I . , , . . . . Id ld ld 1 0' Id

fw- Fig. 2 Axial fatigue of HK31A at 260 'C (500 OF)

L \\

j i ;:i"_ I . , ,.,,,, y; . , . , . , , *

R =O.Ol, wYI

1 ld 106 lo' 10'

w- Fig. 3 Axial fatigue of HK3IA at 150 T (300 OF)

HZ32A (UNS M13320) / 171

. 0 Vacuum . A Bakeout and test in vacuum HY2lA

Composition 3.2Th-2. lZn-0.7Zr-bal Mg Temmrature. O F

Product form Sand-cast test bars Heat treatment T5

-

Modulus of elasticity (avg at RT) 44.8 GPa (6.5 x lo6 psi) RT tensile strengthlelongation 205 MPa (29.7 ksi)/7% RT yield strength 95 MPa (1 3.7 ksi) Test temperature 150 to 370 OC (300 to 700 OF) Test environment Air Failure criterion Fracture Loading condition Reverse bending (R = -1) Surface Smooth Source C.J.P. Ball, et al., Further Progress in the Develop-

ment of Magnesium-Zirconium Alloys to Give Good Creep and Fatigue Properties between 500 and 650 OF, l'hns. AIME, Vol197,1953, p 924

I i tj

150 200 250 300 350 Temperature, O C

Fig. 4 The effect of temperature on the fatigue strength of HZ32A

Composition 0.8Mn-2.0Th-bal Mg Product form Forging-wheel rim Heat treatment T5 Modulus of elasticity (avg at RT) 44.8 GPa (6.5 x 106 psi) RT tensile strength/elongation 235 MPa (34 ksi)/9% RTyield strength 150 MPa(21.7 ksi) Test temperature Room temperature, 200 "C (390 OF), 3 15

l b t environment Air OC (600 OF)

Table 2 Fatigue PrOpertleS Of HM21A-T5 forQlnQS

Failure criterion Fracture Loading condition Rotating beam, axial (R = 0.25) Specimen orientation Tangential Specimen geometry Wheel rim, some notched Kt = 2.0 Surface Polished Source "Magnesium Forging Alloys for Elevated Tempera-

ture Service," TS&D Letter Enclosure, Dow Chemical Co., 24 April 1982

Stre?s, MPP, at cycles: Forging Orientation Fatimetest Suma 105 106 lo' l@ Wheel rim Tangential Rotating beam Polished 110 85 60 60

NocChed 70 55 40 35 Axial Polished 145 115 95 ... (tested at 200 "C) 115 110 105 ... (tested at 315 'C ) 95 as 70 ...

Composition 2.0% Th-0.57% Mg- bal Mg Heat treatment As-received Modulus of elasticity (avgat RT) 44.8 GPa (6.5 x lo6 psi) RT tensile strength/elongation 214 MPa (31 ksi) Test temperature Room temperature Test environment Air and vacuum Failure criterion Fracture Loading condition Fully reversed (R = -1) plane bending Specimen geometry Flat cantilever, '/4 in. thick Surface Polished Frequency 30 Hz Test specifications Some specimens underwent outgassing Source H.T. Sumsion, Vacuum Effects on Fatigue Properties

of Magnesium and TWO Magnesium Alloys, J. Space- craft, Vol5 (No. 6), 1988, p 700-704


Composition O.BMn-2.OTh-bal Q M u c t form Sheet Heat treatment "8 Modulus of elasticity (avo at RT) 443 GPa (6.5 x lo6 psi) RT tensile strength/elongation 255 MPa (36.9 ksi)/ll% RT yield strength 186 MPa (26.8 ksi) Test temperature Room, 204 O C (400 OF), 3 15 O C (600 O F 9

Test environment Air Failure crltenion Fracture Looding condition Axial load (R = 0.25) Spdmen geometry 1.63 mm sheet Source "HM21A-T8 Magnesium Alloy Sheet and Plate,"

Dow Chemical Co., Revised: 24 April 1964

11 . . . , .... I . . . , .... 1 . . . ..... I . . . . . ., 1 0' Id td to'

cvckr f

Fig. 6 Fatigue of HM2lA sheet

Composition O.BMn3.0Th-bal Mg P d n c t form Extrusion Beat treatment F Modulus of elastlcity (avg at RT) 44.8 GPa (6.5 x lo6 psi) Testtemperature Room Test environment Air Failure criterion Fracture Logding condition Rotating beam (R = -1) Specimen orientation L, T, LT Specimen geometry Some notched Kt = 2 Surface Polished S~urce~Magnnesiurn in Design," Form No. 141-21367,

Dow Ch&nicnl Co., 1967

Fig. 7 Rotating beam fatigue of HM3 1 A

Magnesium-Sllwr Alloys: Fatigue Strength at Room Temperature/ 173

Miscellaneous Mg Alloys

W e 1 Magnealum.rllw alloys: fatlgue rtrength at room !uinpmture

temw tblrLncpl lpDde ntb MPI loC Id lob 107 5x107 lo(

Allor

EQ21AsT6 sardcartiog UIUIO~CM, Raafinskam -1 W(37.8) Air

Form and

.,, 113(16) lOO(14.5) 98(14) %(13.9) ... Ibt - -:Ltmos-L--

a d

machined and pofiw

IndbdaJ ld POlirM

Air 1.. ... SE(E.4) ... .., 54(7.8) Saad-tirtg Notched,Kt=2.0 Rotati~gbtrrm -1 QH21A-T6 Sandat UNIotdrcd Rotaringteam -1 Zaoi,,S) Ak ... 135(19.5) llO(16) lM(15.2) lOS(l5.2) ...

.,. Air ... I . . 65(9.4) ... G(9.4) ..I Swat Nolchcd,Kt=2.0 Rotetingkam -1 QE22A-T6 S d ~ t U-, Rotstingbeam -1 275(40) Air .,, lS(21.7) 125(18) llS(16.6) lOS(15.2) lOS(15.2)

machlnedarsd polbW

Sandcart N#db#l,Kt=ZO W a g b e a m -1 .I. Air I . , ,., SS(12.3) o I I U(9.4) 60(8.7)

b~:IElectmnEB21A:Ano~CaetineAlloyDevelopedby~umEle~LM.:BuIletFn4&4,~mElsktron,Ltd.,July W,chdechpniul- and Chsmiorl Campollitlane of Caat Magnenium Auoyq" Bulletin 440, Msgneldum Ele- Ltd,, Much 1981; 7 h b h of Fatigue Strength of Sand Cast Magn&um Al- loye,"T8%DLetterEnclosure, Dow Chemierl &I., UNov 1986.

Composition 2.54bAg-1 .O%Th-f .O%Nd-0.6%2r M u c t Porn Cast Heat trePtment T6 Modulus of elasticity (avg at RT) 44 G h (6.3 x lo6 psi) RT tensile strength/elongation 276 M h (40.0 ksi)/4% RTyieldettPngth210MPa(30.5ksi) Test temperature Room temperature Tast environment Air Failure critwfon Fracture Loading condition Rotating bending, R = -1 Specimen geome$iy Unnatched and U-notched, Kt = 2.0 Frequency 2960 cpm Soufie W. Urrjworth, J.F. f i g , and S.L. B I W ~ W , " Q H ~ I -

A High Performance Magnesium Casting Alloy for Aero- space Applications"

t ' ]I

i l i '0' rd rd ld id

cvdr

El& 1 Notched fatigw strengtb of QH2l

174 / Magne8ium Alloy Fatigue Data

Loading condition Rotating beam, R = -1 Source M. M e n , Magnesium Casting Alloys for Aircmft

Structures, Mod, Cast., Vol5 1, March 1967, p 6062; Aerospace Structural Metals Handbook, Eattelle Metals and 0

Composition 2.2R.E.-2.5Ag-O.7Zr Product form sand Cast Heat treatment T6

482'F - .. - -A-l-6

, . . _ _ . . . . . . . . . . . . . . . . . . . . . . . . -

150 \ I

1u-.

9 . . & .

d - z

*- i

Ip P .

- ThicknesdOrlentatIon

0 . 0.5 in. TT-L a n o %

0 l.Oin. A-T 0 a0

. 0 0.75 in. A-T 0 . 0 . 1.0 in. TT-L

t o 0 . .

Q€BA

Composition 2,2RqE.-2SAg-0.7Zr Prodnct fonn Plate Heat treatment T6 Modulus ofelasticity (avg at RT) 44.8 GPa (63 x 106 psi) RT tensile strengtWelongation 275 MPa (39.8 ksi)/4% RT yield strength 205 MPa (29.7 ksi) Test temperature Room temperature Test environment Air Loading condition Load control, R = 0

1 AK, k i din,

Fig. 3 Fatigue crack growth of QE22A magnesium

10

Spedmen or&ntaUon LT, T-L S e e n geometry C O , thickness 25.4 mm (1 .O in.),

Frequency 7-30 Hz Source O.E. Hart, "Linear-Elastic Fracture Toughness of

19,05 mm (0.75 in.), 12.7 mm (0.5 in.)

QE22A-T6 Cast Magnesium Alloy," LMSGA943552, Lockheed Missiles & Space Co., 1969

Table 2 OE22A crack growth d8ta (R = 0)

k P k M, n u m b s InJeYCk A&biG

Thkktneru: 0.5 hi orbntPtbn: T-t 1 0.4330E-05 5.100 2 0.2800E-05 3.880 3 0.72Oo&M 4.060 4 0.13OoeM 4.400 5 0.1oWEa 4.650

mieknara: 1x75111,; or+mtation: &r 1 0,75M)E-o5 5.470 2 0,7250E-05 5.250 3 0.4MOM5 4.760

5 0.2400w3 4.360 6 0.5600&05 4.600

Thwlnecls: lJh;ori+nmtbn: T-L

2 0.27ooE-05 3.940 3 0.2300E-05 3.600 4 0.1710E-05 3m Thkkm: OJ in.; mieotatbn: LT 1 0.5w)e-o5 4,600 2 0.5Boofi-M 4.1% 3 0.4380E-05 3.940 4 0.8170E-05 4.500 5 0.69008-05 4.760 6 0.59ooE-05 5 . M 1 0.3500505 5.000 8 0.3300&05 4.380

4 0.4H)OMs 4.880

1 O ~ ~ O O E - ~ S 4370

Magnerium-Rare Earth Carting Alloy U S A (UNS Ml2330) / 175

Composition 2.8R.E.-2.6Zn-0.7Zr-bal Mg

Beat treatment "5 Modulus of elasticity ( a s at RT) 44.8 GPa (6.5 x 106 psi) RT tensile strength/elongation 160 MPa (23.2 ksi)/3% RTyield strength 105 MPa (15.2 ksi) Tsst temperature Room temperature

Failure criterion Fracture

Specimen geometry Some notched, Kt = 2 and 5 Surface Smooth, machined, and polished Source 'Tables of Fatigue Strength of Sand Cast Magnesium

Alloys," TS&D Letter Enclosure, Dow Chemical Co., 19 Nov 1965

product form Sand cast LOdhg andition Rotating beam, R = -1

envlronment Air

Table 3 Frtlgue .trsnglh of EZ33A

ComposStion 2.25R.E.-2.25Zn-0.62bal Mg m u d form cast Modulus of elasticity (avg at RT) 44.8 GPa (6.5 x lo6 psi) RT tensile streogth/elwgation 152 MPa (22 hi)#% RTyield strength 103 MPa(l5 ksi) Test temperature Room twnperatum 204 'C (400 T), and

260 'C (500 OF) Test environment Air Failure c M o n Fracture Loading condition Rotating bending, R = -1 TeaspedflcationsTemperaturecomparisons Souroe W. Unsworth, Meeting the High Temperature A m -

$pace Challenge, Light Metal Age, Vol44,1986

cvcfes w. 4 Fatigue strength of PZ33A al morn temperature

1

2 1 3 6 E (0

r- 5 A2-

g, 5 B t

5

lo' 107 10' Cycles cyeb

Fig. 6 Fatigue strength of EW3A at 260 O C Rg. 5 Fatigue strength of EZ33A at 200 O C


\

Heat treatment T5, aged 5 h at 216 'C

RT yield strength 1 10 MPa (1 5.9 ksi) Modulus of elasticity (avg at RT) 44.8 GPa (6.5 x 106 psi)

Test temperature Room temperature ElO'r

d i \ .

Magneslurn alloy

* R=-1.0 O R m 0 . 1 0 R 1 0 . 8

mm Frequency and waveform 40-50 Hz, sinusoidal, secant

Source P.K. Liaw, T.L. Ho, and J.K. Donald, Near-Threshold method

0 0 %

0

- I" , . 10'' 1 10

Fatigue Crack Growth Behavior in a Magnesium Alloy, So: Merall.,Vol 18,1984,~ 821-824 Effective stress Intensity range, A&,

MPa Jrn

Fig. 7 Fatigue crack growth of eW3A-TS magnesium

Composition 14% Li-1 ,O% Al-bal Mg Heat treatment As received Modulus of elasticity (avg at RT) 44.8 GPa (6.5 x lo6 psi) RT teosile strength/elongation 13 1 MPa (19.0 ksi) Test temperature Room temperature Test environment Air and vacuum Failure criterion Fracture Loading condition Fully reversed ( R = -1) plane bending Specimen geometry Flat cantilever, 6 mm (0.25 in.) thick Surface Polished Frequency 30 cps Test specifications Some specimens underwent outgassing Source H.T. Sumsion, Vacuum Effects on Fatigue Properties

of Magnesium and Two Magnesium Alloys, J . Space- cmfr, W 5 (No. 6), 1968, p 700-704

Cycles

- 8 FatigueofLA141Ainairandvacuum

Composition 14.OLi-1 .OAl-bal Mg Product form Sheet Modulus of elasticity (avg at RT) 44.8 GPa (6.5 x lo6 psi) RT tensile etrengtb/elongation 130 MPa (19 ksi)/5% RTyield strength 96.5 MPa (14 ksi)

Test environment Air Failure criterion Fracture Loading condition Reversed bending (R = -1) Specimen geometry 1.58 mm thick Surface &greased, epoxy coated, and urethane coated

Source "Magnesium-Lithium Products," Brooks and

'M temperature Room temperature 1

k e q u e n c y m c p m

Perkins, Inc.

cyr

Flg.9 FatigueofLA141Awithvariouscoatings

M1A (UNS M15100) / 177

Composition 1.2Mn-bal Mg Product form Extrusion Heat treatment F Modulus of elastkity (avg at RT) 44.8 GPa (6.5 x 106 psi) Test temperatum Room temperature W t environment Air Failure criterion Fracture

Loadlog condition Rotating beam (R = -1) Specimen geometry Some notched, Kt = 1.8 Surface Polished, S,C.F, = 1.8 Test spedflicatrons R = -1 Source “MagnesiuminDesign,” Bulletin 141-213, Dow

Chemical Co., 1967

Tabk4 Ranting beam(R=-l)tatlguestrengthofUllA=Fexhus~s

Surfaceor Fatigue hit, hlPa, at cycles: Albv nwortesr R value shwseonccnbatioa 10s 106 107 5 x 10’ MIA-F -1 polished 107 a8 85 83

1.8 16 54 50 48

Composition ZnO.01 m a , A1-0.01 max, Mn-1.62, Cu-0.02,

product form Sheet Modulus of elasticity (avg at RT) 43 GPa (6.2 x 1 O6 psi) RT tensile strength/elonption 200 MPa (29 W)/6% RT yield strength 107 MPa (15.5 ksi) Test temperature Room temperature Test environment Laboratory air Loading condition Load control, R = 0,0.5,0.67, and 0.78

Si-0.006, FeO.007, Ni-0.003 max, Mg rem

R = O.Oo0 R = 0.m R 0.670 R = 0.780

P

8

A

A

AM503 rhwt

L-T wlenteUon

1 AK, k6i din.

Flg. 10 daJdNdatafmAM503 magnesium

10

Specimen orientation L-T Specimen geometry MO 0.1 in. (2.54 nun) thick, 10 in.

Source G. Pook, Fatigue Crack Growth Characteristics of W o Magnesium Alloys, f i g . Fruct. Mech, Vol5 (No.

(254 mm) wide ~ U ~ C Y 3.5-10 Hz

4), 1973, p 935-936

Tabk 5 Mi A (AM503) crack growth data ~ _ _

dalar, irlcyele AK, b f i

h p b numkr

R - 0 1 0.4W-06 2.000 2 0.1mE-05 3.000 3 0503OE-05 4.000 4 0.10M)m 5.w0 S 0.1960G04 aoM) 6 0.3280EW 7 m 7 0.5 130E.04 8.000 R-03 1 0.1430EO5 2” 2 0.5550E-05 3.m 3 0.1460504 4.m 4 o.xno504 5.000 5 0.56M1E-04 6.000 6 0.94WE-w 7m 7 0.1480&03 8.000 R-A67 I 0.1660m 2.m 2 0.646oE-05 3,000 3 0.1690m 4MM 4 0.358oM)4 5 .000 5 0.6590E-04 6.000 6 0.11ooE-03 7.000 7 0.17W)Mu 8.000 R - 0.78 1 0.2560E-05 2.000 2 0.9!JSOE45 3m 3 0.2610E-04 4.030 4 0.5510504 5.000 S 0.1020E03 6.000 6 0. I7M3E-03 7.000 7 0,2660E-03 8.000

178 / Magnoslum Alloy Fatigue Data

Composition 3A1, lZn, bal Mg Heat treatment Annealed for various grain sizes (see table) Condition Hexagonal crystal structure with some deforma-

Hardnw 50 HB Modulus ofelasticity (avg at RT) 43 GPa (6.2 x ]@psi) RT ten& strengthleiongation 240 to 290 MPa (35 to 42

RT yleld strength 180 to 220 MPa (26 to 32 ksi)

tion by twinning

ksi)

Table 6 GAS21 : Plastic and elastic fatigue parametm

Test environment Room-temperature air Failure criterion Fracture Loading condition Axial and torsional strain control Specimen geometry Hollow specimens Gauge length and thickness 25 mm long, 1.5 mm thick Frequency 0.03 Hz, hiangular Source Cyclic Plastic Deformation by 'Ikinning of a Magne-

sium Alloy GA3Z1, Advanced A1 and Mg Alloys, ASM International, p 837-846

Eept Grain Ektk ~4rametCra pkrtic pvlmten tRPemoat size a,/ E b 4 C ~tprtlc porrmetem Anneakdat32O0Cfor2h 3 Irm 0.0314 -0.262 76.99 -1.56 B e f o r e W n g

Anneakdat540 'C for 2 h 0.016 4 . 1 8 2 1.084 A 8 1 Before breaking

Recrystallization annealed 80 wn 0.0238 -0.245 n.93 -1.451 No breaking

E I 43QPa. Composition (wt%): 2.8-3.5 Al, 0.6-1.6 Zn,OS Mn bin), 0.1 91, 0.06 Cu, 0.006 Fa, and 0.005 Ni (man)

0.094 A 5 8 *b=wi

0.169 A 6 1 Afkrbrraldng

at 540T for 24 h

I I J ld lo3 1 o4 1$

Cycles to failure

Fig. 11 Plastic strain life of GA3Z1, For testing under tension-compression, the presence of twinning was noticed for any deformation rate for the grain sizes equal to Wand 80 pm. %inning is the cause of a modification of the slope of the plastic line. The plastic deformation for the larger grain sizes presents acommon slope for deformation zones where twinning is noticeable. The second line corre- sponds to the 3 pm specimen, for which twinning pmctically does not exist.

Table7 Chemical composition of some wrought Russian magnesium alloys, wpk

Al Zn Zr Y Cd Mn Ca Ce La Nd LI desinmtba VMD- 10 4.04 0.75481 0.49.0.50 7.1-7.9 0394.63 MLB < I , 5.56.6 0.7-1.1 0.24.8 .,, ... ... ... ... ... IMV6 0.12 1 1 1 ,,. 7.8 0 1 0.55 0.49 0.11 ... .., MA2- 1 4.17 0.85 .,. ,,. ... 0.5 ... ... ... ,,. .., MA15 ... 3.15 ... , I , ,.. ... 1.88 ... 0.83 . I , ... MA12 ... 0.44 ... . * I I > , ,.. ... , I , . , I 2.9 . I .

MA2 I 5.4 I .o . I , ... , I . ... 4.7 . * I .,. 8.6 MA18 .,, .., ,,, #, . 1 1 1 , I , .,. ,.. I . . .,. . I .

AUoV

Russian Alloya: Fatigue Crack Growth / 179

1 10 102 &, MPa drn

Fig. 12 Fatigue crack growth rate curves for magnesium alloys at mom tempera- tureand-135'C. Source: V.A. Serdyuk,Pmbi. P m h n . , Vol 11,1980, p 18-23

1 10 Id &, MPa 4tn

14 Fatigue crack growth rate data for MA12 in different stluaural states. Source: N.M. Orinberg and V.A. Serdyuk Pmbl Pmchn, WI 10,1978, p 16-52

I 10 K,-MR.lm

I

FQ. 13 Fatigue crack growth rate for magnesium alloys. Source: N.M. Grinbeg, V.A. Serdyuk, T.I. Malinkina, and A.S. Kamishkov, Pmbl. Prochn, Vol 1,1982, p61-67

1 o ' O F ./I , . . , . . . I . . . . . . . 1 10

k, MPa +n 14

Fig. 15 A comparison of fatigue crack growth rate curves for differrnt parts of an MA15 weld joint BM, bass metal; WM, weld metal; HA& heat-affected zone. Source: S.Y. Yarema O.D, Zinyuk, andT.1. Malinkina, F k - K h i n Mekk Mater, VOI 17(N0.5), 198l,p72-76

Titanium Alloy Fatigue Data

Titanium Alloys Fatigue and Fracture Adapted from the article "Fracture Properties of Titanium Alloys" in Application of Fracture Mechanics for Selec- tion of Structural Materials (ASM, 1982) with revision by H. Margolin, Polytechnic University

Titanium is used for two primary reasons: (a) structural efficiency, which derives from i p combination of high strength and low density; and (b) resistance to corrosion by chlorides and oxidizing media, which derives from its strong passivation tendencies. Titanium, like most structural materials, is supplied in all mill product forms, and several titanium alloys are available to meet specific needs. Most important among titanium alloys isTi-6A1-4V. Offering a strength-to-density ratio of 25 x 106 mm (1 x 106 in.), Ti-6A14V has found application for a wide variety of aerospace hardware. Jet aircraft manufacturers are the principal con- sumers of titanium in this market. The Ti-6A1-4V alloy is often specified for critical parts, the failure of which could result in loss of an entire system. In these situations, the higher acquisition cost of titanium can be more than offset by its reduced costs of ownership. Because of its great popularity, Ti-6A1-4V has become the best understood of all titanium alloys, and much of the property data obtained on this alloy have been stored in computer data banks and is available for statistical analysis.

Several metallurgical and environmental variables have been identified that influence the h c t u r e behavior of titanium alloys in general and of alloy 'Il-6A1-4V in particular; the effects of these variables will be discussed in detail in this chapter. It is beyond the scope of this chapter, however, to provide design-type data to the user requiring the ultimate in performance. That type of information must either be generated by the uscr or bc obtained from other sources.

The references and the Appendix at the end of this chapter contain additional mechanical property data. The purpose of this chapter is to provide the reader with general guidelines that indicate what variables have what effects on toughness and fatigue crack propagation. Among the metallurgical variables of importance are composition, microstructure (as it depends on processing and heat treatment), and crystallographic texture. Environmental factors are discussed also. Due to its importance, the metallurgy of alloy Ti-6A1-4V is treated first, followed by a brief discussion indicating how certain other titanium alloys differ metallurgically from Ti-6A1-4V. The remainder of this chapter reviews,

in highlight fashion, what is known about fracture toughness and fatigue crack propagation, including the effects of testing environments, for the most common titanium alloys.

Summary. Titanium and titanium alloys have a wellearned reputation for reliability in service. In no small measure, this is a result of the double and triple vacuum arc melting procedures employed throughout the industry in producing the alloys. That reputation is protected also by the excellent corrosion resistance exhibited by titanium. Titanium does not corrode in salt water. Crack initiation in titanium is almost always mechanically induced; only under very special circumstances will cracks initiate due to a combination of an environment and static stress.

Because of the many possible effects of chemistry, microstructure, texture, environment, and loading, it is not possible to quantify the crack growth behavior of titanium alloys unless these factors are closely controlled. Alloys within a given class, such as alpha-beta alloys, show parallel trends in their fracture toughness and crack propagation behaviors. To the extent that they have been studied, the trends for interstitial effects are similar for all alloys, the higher levels of interstitials leading to faster fatigue crack propagation (FCP) and lower KI,. A similar trend is observed for variations in microstructure. Those microstructures (Wid- manstiitten or recrystallization annealed) that give the highest KI, values generally yield the lowest crack growth rates whether under fatigue or sustained loads. Moreover, the environmental media studied tend to exhibit similar rank orders of severity among Kk, FCP, and sustained load crack propagation. Salt water appears to be the most severe of the media studied. Readers interested in additional quantitative comparisons may consult the original references from which this chapter was drawn or may perform their own tests. Finally, those readers who are interested in the available design information or the underlying metallurgy may consult the general references list at the end of this article. The references that are cited refer primarily to alloys for which standard specifications exist.

lltanium exists in two crystalline states. In pure titanium, the low- temperature a phase is stable at temperatures below about 883 "C (1621 OF) and crystallizes in the hexagonal close packed structure with a c/ara- ti0 of 1 .58, which is slightly less than the ideal ratio for packing of rigid spheres. The high-temperature p form is a body centered cubic phase that is stable from about 883 "C (1621 OF) to the melting point.

The transformation temperature and phase compositions of titanium can be altered by alloying additions. Elements that increase the transformation temperature are known as alpha stabilizers, and those that decrease it are called beta stabilizers. Other, sparingly soluble elements, when present in excess of their solubility limits, may form compounds or second phases of essentially pure solute. Of the elements commonly present in Ti-6A1-4V, carbon is a compound former; vanadium, iron and hydrogen are beta stabilizers; and aluminum, oxygen, and nitrogen are alpha stabilizers.

Metallurgy of Ti-6AI-4 V Standard grade Ti-6A1-4V becomes 100% beta phase at tempera-

tures above about lo00 OC (1 832 OF). Below this temperature, alpha and

beta phases coexist. Ti-6A1-4V is thus a two-phase alloy with the beta phase present even at cryogenic temperatures.* This comes about because 4 wt% vanadium exceeds the alpha solubility limit. When additional phases occur, it is usually because the alloy has been contaminated with an impurity (such as boron) or because an element such as yttrium has been added for grain refining purposes. To avoid problems caused by impurities, maximum impurity levels are limited by specifications that cover composition limits. At mom temperature, Ti-6A1-4V is about 90 vol% alpha phase. Thus, the alpha phase dominates the physical, chemical, and mechanical properties of this alloy.

Alloy Ti-6A14V may be obtained in two basic ranges of composition: the standard grade and the "extra low interstitial" (ELI) grade. In the ELI grade, oxygen is held to less than 0.13 wt%, whereas the maximum oxygen content of the standard grade is commonly 0.20 wt%. The two grades have the following typical composition ranges:

*See later discussion of beta alloys.

184 / Tltanium Alloy Fatlgws Data

CommUion,wt% Elemeat stsndprd ELI Aluminum 5.75-6.75 550.650 vanadium 3.54,5 3545 Iron 0.25 max 0.25 max Oxygen 0.20 mrtx 0.13max Maogm 0.05 m 0.05 ma% Hydropen 0.015 max 0.015 max Csrboa 0.08 max 0.08 max

nitrogen, hydrogen, and carbon are the interstitial elements. Except for carbon, they are all readily soluble in titanium. In general, they increase strength and decrease ductility, and in this sense have effects quite similar to those of metallic alloying additions. Carbon has limited solubility and is a strong compound former, but carbon levels are so low in commercial products that carbides iue virtually nonexistent. Hydrogen, aside from being a beta stabilizer, has other unique features. It is soluble as well as highly mobile in titanium. Hydrogen can, therefore, be picked up during processing operations such as forging, heat treating, and pickling. By the same token, hydrogen can be removed from titanium by vacuum annealing operations at temperatures on the order of 700 to 900 @C (1292 to 16S2 "p). in vacuum annealing operations, both the metal and the furnace surfaces must be clean to ensure effective outgassing, Depending in part on the amount of beta phase present, hydrogen at sufficiently high levels is manifested by hydride precipitation and embrittlement. Embrittlement may occur as a delayed reaction. Residual stress gradients lead to hydrogen gradients which

may localize the hydrides (Ref 1 and 2). Alwninum tends to increase the apparent solub en in alpha titanium (Ref 3).

However, of hydrogen activity (Ref 4 and 5) have shown that Al activity reduces the solubility of hydrogen in alpha (see discussion in section on beta alloys). The flndings of Ref 3 have been ex- plainedon the basis that A1 additions increase the strength of alpha, mek-

phase of alpha+ beta alloys. For these reasom, welding o€unalloycd titanium to alloys such as TI-~AI-~V is not recommended lest the h y h - gen normally present in Ti-6A14V migrates to the unalloyed titanium and causes embrittlement {Ref 1). Hydrogen in titanium is d y con- mlled, and speciticatio

Mic-tare attan Behavior. Control of microstructure is the primary key to successful application of alloy Ti-6Al4V. It depends on both processing history and heat treatment. The microstructure that combines highest strength and ductility is not the microstructure that provides optimum fracture toughness or resistance to crack growth. The over-all effects of processing history and heat treatment on microstruchue 8re very complex. However, the present dims- sion will illustrate those features most likely to be found in the alloy by the user.

Figure 1 illustrates the effect of solution temperature on the microstructure abtaincd at acooling rate equivalmt to that obsetvedin parts of moderate thickness. In Fig. l(a), the Widmanstlltten-like transformed

maximum allowable content.

Q

Fig. 1 Typical microsmcturer of alloy Tl-6A14V. showing effect of solution temperature. (a) 11310 OC (1850 OF), 1 h, encapsulated cool; SOOX, 8) 982 *C (1800 OF), 1 h, encapsulated cool: 5oox. (c) 927 'C (17OO "p), 1 b encapsulated cool; 435x

Titanium Alloys Fatigue and Fmcture I 185

Microstnroture of alloy Ti 00 OF), 1 h, very slow cool;

after recrystallization annealing.

ere n up after forging led (1725"Q; 182.5~

ult of limited working in

the alpha phase is fully recrystallized and has a very 1

186 /Titanium A

lloy Fatigue Data

Fig. 5 Illustration of quenching rate effect on microstructures of alloy “i-6A

1-4V

Titanium Alloys Fatigue and Fracture / 187

Elastic modulus in dimtion mrml to prim plma [llal, QPa

Distance from origin to isotherm in direction of interest is equal to modulus.

Fg. 6 Plot of elastic modulus vs direction in single crystal of titanium for various temperatures. Distance from origin to isotherm in direction of interest is equal to modulus. Source: Ref 14

shown that this phase is an artifact produced during the preparation of foils for electron microscopy (Ref 13).

Deformation Modes. Crucial to the toughness question is the size of the plastic zone that can form ahead of apropagating crack. That size, simplistically, depends on the yield strength, and this in turn depends on the factors discussed in the upcoming discussion on sources of strength. Having a high yield strength and a relatively low elastic modulus, Ti- 6A1-4V can store more energy elastically than most metals before plastic deformation begins. The elastic modulus depends on the direction in which it is measured in a single crystal of titanium. This feature is illustrated in Fig. 6 (Ref 14).

The flow stress also depends on the direction of measurement.Jn directions normal to the hexagonal axis of an alpha titanium crystal, a slip, on the prism, pyramidal, and basal planes, is the primary deformation mode. In directions parallel, to the hexagonal axis, twinning and c + a slip act to accommodate the plastic strain. Each slip and twinning mode has its own unique flow stress and amount of strain that can be accom- modated.

The plastic zone ahead of an advancing crack is, therefore, not uniform in cross section. It varies in a macroscopic sense in response to the microsmrcture (phase, shape) discussed in the previous section. It also varies from grain to grain in accordance with crystal type, whether alpha or beta, and with crystal orientation. To complicate matters further, Pois- son's ratio and its plastic counterparts necessarily depend on direction on both the macro and micro scales. Furthermore, the true strain at ultimate load is not a linear function of alloy content even in the Ti-A1 binary system (Ref 15). Events occumng in and around a crack tip and its associated plastic zone in Ti-6A1-4V are, for these reasons, complex indeed. Toughness in the Ti-6A1-4V alloy is not yet quantifiable from first prin- ciples. Nevertheless, there is a great deal of empirical information available for Ti-6A1-4V from which some general rules can be developed.

Summary. The mechanical properties of titanium alloys thus depend on alloy chemistry, microstructure, and metallographic texture

through its influence on elastic and plastic anisotropy. The influence of these factors on strength, toughness, and resistance to environmental effects on crack propagation is discussed further in the following sections.

The Ti-6A1-4V alloy derives its annealed strength from several sources, the principal source being substitutional and interstitial alloying of elements in solid solution in both alpha and beta phases. Alumi- num is the most important substitutional solid solution strengthener. Its effect on strength is linear (Ref 16). Other, less important sources of strengthening are interstitial solid solution strengthening, grain size effects, second phase (beta) effects, ordering in alpha, age hardening, and effects of crystallographic texture (Ref 17). Aluminum inTi-6AMV, as suspected by Williams and Blackburn (Ref 18), gives rise to some tendency toward ordering in the alpha phase, the ordered product being Ti3AI (Ref 19). Ordering in the alpha phase contributes perhaps 15 to 35 MPa (2 to 5 ksi) to the strength of standard Ti-6A1-4V, and contributes less than this to the strength of the ELI grade. Ordering also appears to degrade toughness. The effect of crystallographic texture is to introduce directionality into the strength equation. Relative to the hexagonal axis in alpha, strength (and modulus) is high in the parallel direction and low normal to that direction. Because metalworking operations tend to produce preferred crystallographic orientations in alpha grains, strength becomes an anisompic quantity in most product forms. This feature can be minimized by proper processing and is rarely of direct concern. In some instances, it can be an advantage.

Because the beta phase present in alloy Ti-6A14V can be manipu- lated in amount and composition by heat treatment, the alloy is respon- sive to heat treatment. The p + a + /3 reaction at low temperature leads to increased strength. The key is to quench from high in the a + p field and then age at a lower temperature. A typical strengthening heat treatment consists of heating for 1 h at 955 "C (1750 OF) and water quenching, followed by heating for 4 h at 540 "C (loo0 OF) and air cooling. Re- sponse is limited in a practical sense, however, by two factors: (a) the small amount of beta in Ti-6A1-4V and (b) section size. The first factor puts an intrinsic ceiling on the increased strengthening response available-about 280 MPa (40 ksi) in thin-gage material. The second factor relates to depth of hardening, because Ti-6A1-4V is not effectively hardenable in sections greater than 25 mm (1 in.) in thickness. The Ti-6AI- 4V alloy is, therefore, most commonly used in the annealed condition.

Other Alpha-Beta and Alpha Alloys Metallurgy of High-Strength Alpha-Beta Alloys. Two alloys that

fall in the high-strength alpha-beta class are Ti-6A1-6V-2Sn, which is used in airframes, and Ti-6A1-2Sn-4Zr-6M0, which is used in jet engines. Alloy Ti-6A1-2Sn-4Zr-6Mo is also often classified as a super alpha alloy. Both of these alloys are stronger and more readily heat treated than TidA1-4V. These features arise from the increased solid solution strengthening afforded by tin and zirconium, which have relatively small effects on the transformation temperature, and from the increased amounts of beta phase that result from the larger vanadium and molybdenum additions. Both vanadium and molybdenum are beta stabilizers. The Ti-6A1-6V-2Sn alloy contains the beta stabilizers copper and iron in combined amounts up to 1.4 wt% for enhanced strength and response to aging. Alloy Ti-6A1-2Sn-4Zr-6Mo is also useful at the moderately elevated temperatures from 425 to 480 OC (800 to 900 OF). This alloy combines high tensile strength with good creep resistance. The alpha phase tends to order more readily in these alloys than in alloy Ti-6A1-4V. More- over, the transformed alpha platelets in Ti-6A1-2Sn-4Zr-6Mo tend to be narrower than those in Ti-6A1-4V, and formation of packets of parallel platelets is less likely. For both Ti-6A1-6V-2Sn and Ti-6A1-2Sn-4Zr- 6M0, the nose of the C curve defining the p + a + transformation as it depends on time and temperature is shifted to lower temperatures and longer times than for Ti-6A1-4V. Martensite does not form in ordinary situations.

Alpha is the dominant phase in these alloys but to a lesser extent than in Ti-6A1-4V. The physical metallurgy of these alloys is otherwise very similar to that of Ti-6A1-4V.

188 I Titanium Alloy Fatigue Data

Metallurpy of %per Alpha" Alloys, Alloys Ti-6A1-2Sn-4Zr- 2Mo and Ti-8AI-lMo-IV are in the "super alpha" class. They are used primarily in jet engine applications and are useful at temperatures above the n o d range for "i-6AI-4Vb Alloy Ti-6A1-2Sn-4Zr-2Mo may be modified with silicon additions of up to 0.1%. and, when beta annealed (i.e., annealed by heating above the transformation temperature), the modified alloy provides the highest creep strength and temperature capability of all commercial titanium alloys currently (1980) produced in the United States. The Ti-8Al-lMo-IV alloy has the highest modulus and lowest density of any commercial titanium alloy. Each of these alloys tends to order in the alpha phase more readily than does Ti-6Af-4V. Also, the note of the C curve defining the + a t B transformation is shifted upward and to the left, or to higher temperatures and shorter times, in comparison with Ti-6AI-4V. Martensite forms more readily in either of these alloys than in Ti-6AI-4V.

TI-SAI-IMO-IV has limited usefulness and both Ti-6242 and Ti- 62428 have wider applicability. A further modification of 73-6242 is TiMetal" 1 100 (Ti-6A1-2.7Sn-4Zr-0.4Mo-0.45Si-O,O3Fe-0.0702), which offers about a 55% creep advantage over Ti-6242 (Ref 20). "IMetal" 1100 is not in wide service, but it offers the advantage of relatively easy processing. Creep resistance is enhanced by producing a transformed, Lea, WidmansUtten alpha structure in the super alpha alloys. ForTiMetal@ 1100, final forging is carried out in the beta field, and this is followed by a stabilization heat treatment at 600 "C (1 1 10 OF) for 8 h.

Another relatively new super alpha alloy is IMI 834 (Ti-5.7AI- 3.9Sn-3.5Zr-0.49Mo-0.84~0.33Si-0.14Fe-O. 126C+-O.O58C). 'IiMetal" 1100 has beuer creep resistance but lower fatigue resistance than IMI 834. This latter alloy is processed high in the alpha-beta field for a good combination of creep resistance and fatigue strength. A comparison of the two alloys is reported in Timet HTL Report "High-Temperature Al- loy Comparison Ti- l 100 and 1MI 834" (P. Bania, July 1990).

Generally speaking, these alloys contain less beta phase than Ti- 6AI-4V. Age hardening treatments m thus not very effective and are, moreover, deleterious to creep resistance. These alloys therefore are usually employed as solution annealed and stabilized. Solution annealing may be done at a temperature some 35 O C (63 O F ) below the transformation temperature, and stabilization is commonly produced by heating for 8 hat about 590 "C (1 100 OF).

At high temperatures. dynamic strain aging arising from aluminum, silicon and tin, and perhaps oxygen and zirconium, is thought to conuib- ute to the creep resistance of these materials.

The alpha phase dominates the properties of these alloys to a greater extent than it does in n-6AI-4V. The metallurgy of the super alpha alloys is otherwise similar to that of Ti-6A1-4V.

Metallurgy of Beta Alloys An alloy is considered to be a beta alloy if it contains sufficient beta

stabilizer alloying element to retain the beta phase without transfonna- tion to martensite on quenching to room temperature. A number of Ti alloys contain more than this minimum amount of beta stabilizer alloy addition. The current status of beta alloys is thoroughly reviewed in Ref 2 1.

Alloying. Beta iSOmOrphOUS elements such as Mo and V require more alloy addition on a weight percent basis to retain beta than do alloying elements such as Cr and Fe, which are eutectoid formers. Al- though less alloying element is required toretain the beta phase when eutectoid formers are used, they cannot be used alone to retain beta, because on long-time holding at elevated temperatures, these alloys de- compose to form alpha plus compound. These decomposed structures have much poorer ductility than the alpha-beta alloys have prior to decomposition. One such early alloy was the li-3A1-5Cr alloy.

As a consequence of this decomposition, beta alloys are usually combinations of beta isomorphous and eutectoid former elements. The presence of beta isomorphous alloying elements reduces the tendency for compound formation by increasing their solubility in the beta phase (Ref 22). In addition, because segregation during melting is less of a problem for beta isomorphous elements than for eutectoid formers, beta

Table 1 Beta otabilitlna elements

Betastabilizer me Mo IsanorphwS V Ixrnorphous W Isarorphour Nb 1So-P Ta lsmnorphous

Eufectoid Fe CT Eutectoid cu Euiectoid Ni EutElOM co EulectoM Mn Eumoid Si Eufectoid

D., wt % (a) 10 I5 22.5 36.0 450

3.5 6.5

13.0 9.0 7.0 6.5 .,.

9.4(17) 12.2 (22) 3.9 0) 7.2(13) 2 2 (4)

17.8 (32) lS.O(n) 122(22) 2 2 2 (40) 21.108) 22.2(40) 38.8 (m)

(a)Appzcudmab wt% needed to retain 100% beta uponquenching. (b)Appmhate amount~transusreductionperwt%addition.Note:Bania~ascri~dtoAi a negative value for retaining beta and haa put thb value equivalent to the vdue ofMoinretainiugbeta.Source:W23

Table 2 Beta alioyr of current interest

Commition, w t % Common name PrlIlCiFlal w Ti-3AI-BV-6Cr-4ZI4Mo Betacar 38.644 Springs TI-lOV-2R-3AI TI-10-2-3 Ab fiames TI. 15V-3Cr.3Sn-3AI n- 15-3 Strlp pmducible, cold fwmable,

Ti-l5M+2.7Nb-3Al.0.2Si m 2 1 s Oxidation miatan! and candidate age hardenable, weldable

forfompositemahix

source: Ref 23

alloys tend to have larger amounts of beta isomorphous than eutectoid former elements.

Since the ability to retain the beta phase depends on the rate of working through the alpha + beta phase field, the retention of undecomposed beta is also a function of section size. Thus, for larger section sizes, greater beta alloy content is required.

Bania (Ref 23) has compiled a list of beta stabilizing elements and their ability to retain beta on quenching (Table 1). Table 1 indicates that. on the whole, eutectoid former elements, in comparison to isomorphous elements have a larger tendency to lower the beta transus per wt% addition and require a smaller wt% addition to retain the beta phase.

It is possible to sum the beta retaining power of a group of alloying elements by adding the fractional equivalents of the beh retention wt% required for each element. For example, 5 wt% of Mo represents half the Mo required to retain beta and 1.75 wt% of Fe represents half the amount to retain beta (Table 1). Thus, an alloy containing 5 wt% Mo and 1.75 wt% Fe should be able to retain beta on quenching.

There is no truly stable beta alloy because even the most highly al- loyed beta will, on holding at elevated temperatures. begin to precipitate omega, alpha, Ti3AI. or silicides, depending on temperature, time, and alloy composition (Ref 21, p 173-1 85), All beta alloys contain a small amount of A!, an alpha stabilizer, in order to strengthen alpha which may be present after heat treating. The composition of the precipitating alpha is not constant and will depend on the temperature of heat treatment. The higher the temperature in the alpha + beta phase field, the higher will be the A1 content of alpha.

Beta Alloy Compositions of Present Interest, There is no single beta alloy that has the same broad applicability as Ti-6A1-4V. Conse- quently, specific alloys are used because their properties suit aparticular application. in general, retained beta alloys are used for workability, corrosion resistance, and the ability to heat treat larger section sizes in which beta has been retained. Beta alloys also tend to have higher density and lower elastic modulus values than alpha alloys. Beta alloys also have a tendency to alloy segregation (Ref 23). Table 2 lists some beta al-

Tftanlum Alloys Fatigue and Fracture / 189

loys of current interest and their principal uses. At present, beta alloys constitute a small fraction of titanium usage,

There is current interest also in using the eutectoid forming alloys to reducethecostofbetaalloys. ATi-4.5Fe-6.8Mo-l.SAlalloy iscurrently being studied because of the cost advantages of using a ferro-molybdenum master alloy. An early alloy with high iron contents was the Ti-1 Al- 8V-5Fe alloy developed for use as fasteners which q u i r e high strengths. Still another alloy being developed for fasteners also has high iron contents, 'K-6V-6.2Mo-5.7Fe-3Al (Ref 23).

Beta alloys are being employed in the McDonnell Douglas C- 17 and the Boeing 777 (Ref 23). 73-10-2-3 forgings have been used extensively on the Boeing 777, but particularly for the landing gear (Ref 21, p 335- 345). The Beta C and the Ti-15-3 alloys are being used and it is antici- pated that Beta-21s will find service in the nacelle ma BetaC, which is hardenable to section sizes of 1 15 mm (4.5 in.) has potential for use in a water brake for aircraft carriers (Ref2l.p 361-374).

Table 3 lists typical minimum property guarantees for titanium alloy mill products. In Table 4, the effects of temperature on strength are shown for the same alloys, and data for unalloyed titanium are included to illustrate that the alloys not only have higher room-temperature strengths but also retain much larger fractions of that strength at elevated temperatures.

Table 5 lists typical specifications for the alloys discussed here, These alloys are covered also by numerous commercial specifications, and design information is readily available. More extensive listings of specifications m given in the reference book Materials Properties Handbook: Titanium Alloys (ASM, 1994).

In terms of the principal heat treatments used for titanium, beta annealing decreases strength by 35 to 100 MPa (5 to 15 ksi) depending on prior grain size, average crystallographic texture, and testing direction. Solution treating and aging can be used to enhance strength at the expense of fracture toughness in alloys containing sufficient beta stabilizer (that is, 4 wt% V or more).

Fracture Toughness Fracture toughness can be varied within a nominal titanium alloy by

as much as a multiple of two or three by manipulating alloy chemistry, microstructure, and texture. Some trade-offs of other desired properties may be necessary to achieve high fracture toughness. Plane-strain frac- hue toughness, Kk, is of special interest because the critical crack size at which unstable growth can occur is proportional to ( K I C ) ~ and strength is often achieved in titanium alloys at the expense of Kk.

The main purpose of this section is to indicate the scope of possibili- ties, as well as some of the property trade-offs required, for obtaining high levels of fracture toughness in titanium alloys. A further purpose is to review some of the specific variables that are known to affect fracture toughness.

Effeets of Alloy Chemistry. There are significant differences among titanium alloys (Ref 24). but there is also appreciable overlap in their properties. Table 6 gives examples of typical plane-strain fracture toughness ranges for alpha-beta titanium alloys. From these data it is apparent that the basic alloy chemistry affects the relationship between strength and toughness. From Table 6 it is also evident that transformed microsvuctures may p t l y enhance toughness while only slightly reducing strength.

Within the permissible range of chemistry for a specific titanium alloy and grade, oxygen is the most important variable insofar as its effect on toughness is concerned. This is readily shown by the data for Fer- guson and Berryman (Ref 25), who reported strength and KI, values for specimens of alpha-beta processed and recrystallization annealed Ti- 6A14V. Regression analysis of their data shows that for each 0.01 % increase in oxygen, toughness is reduced by about 3.7 M P a 6 (3.4 k s i G ) . Whether this is a direct effect or an indirect effect, in the sense that oxygen increases strength and the strength increase reduces Kk, remains to be determined. Multiple regression analysis of the Ferguson and Berryman data, where both oxygen content and tensile strength are assumed to be independent variables, shows that tensile strength is the dominant variable (the residual effect of oxygen does not reach statisti-

Table 3 TYDicaI milhawranteed roomtemwraturetenslle DrooedOB for selected tltanium allova

DtrtiMY Ullimrte strength YIeldalrennth Ebngstba, RedUetloll

AUOY m hi m h i 'k inoleo,% Ti.6A14V 895 130 825 I20 10 20 Tl.6Al6V.2Sn 1065 155 995 145 10 20

T14Al-2Sn-4Zr.2Mo 895 I30 825 1 20 to 25 ~ * S A l - l M ~ IV 895 130 825 120 10 20

T I - & ~ I - ~ S & ~ Z ~ - ~ M O 1030 I50 965 140 10 m

Table 4 Fractlon of room-temperature strength retained at elevated temperature for several tltanium alloye(a)

TidAJ-ln- Ti-MI-ZSn- Tempemturn UdloYed n T i M M V TI-~AI-~V-~SO 4zldMO 4zI.2Mo lI-llM)(a) lAII-834 oc Qp TS YS Ts YS Ts YS TS YS TS YS TS YS Ts YS 93 200 0.80 0.75 0.90 0.87 0.91 0.89 0.90 0.89 0.93 0.90 0.93 092 ... ...

204 400 0.57 0.45 0.78 0.70 0.81 0.74 0.80 030 0.83 0.76 0.81 0.85 0.85 0.78 316 600 0.45 0.31 0.71 0.62 0.76 069 0.74 0.75 0.77 0.70 0.76 0.79

0.72 0.65 0.75 0.76 427 800 0.36 0.25 0.66 0.58 0.70 0.63 0.69 0.71 482 900 0.33 0.22 0.60 0.53 I , . ,.. 0.66 0.69 0.69 0.62 0.n 0.74 ... .., 538 loo0 0.30 0.20 0.51 a44 ,.. ... a 6 1 0.66 0.66 0.60 0.69 0.69 I ( ( .I,

0.63 0.61 593 1100 .., ... .,. .,. ... ... ,,, ... .,. ... 0.66 0.63

... ...

... ..,

(a) Short time t e d e teat with lese than 1 h at temperature prior ta test

190 / Tknium Alloy Fatigue Data

Table 5 TLpical speclflcatlonr lor tltanium and tttanlum alloys

M.tarisl AMS Militan MIL-I Unalloyed Ti 4900 9046,9047 Ti-6AI-W 4911 9046,9047 Ti-6AI-4V ELI 4907 9046,9047 li-6A1.6V-2Sn 4918 9046.9047 l7dAl-2Sn4ZrdMo 498 1 9w7 TMAI.ZSn-4Zr-2Mo 4929 9046,9047 Ti-8AI-lMc- 1V 4915,4916 9046,9047

Tabk 6 Typical fracture toughnrss d hlgh-rtnngth tltanlum alloys

Frrture tough-

& Alphm yidd stRngth A h mombolopv m ksl Ti-W-4V quiaxed 910 I30 44-66 40.60

Transformpd 875 125 88-110 80.100 Ti-6AldV-2Sn Equiaxed 1085 155 33-55 30.54

"hnsfaned 980 140 55-77 5Q-70 T1-6Al-2Sn-4Zr-6Mo Equiaxed 1155 165 22-23 20-30

msfumed I120 160 33-55 30-50

source:Ref!u

cal significance). This implies that, if oxygen affects Kb, it does so through its strengthening effect. The solid solution strengthening effect of oxygen is further complicated by the fact that oxygen tends to promote the formation ofTi3Al (Ref 19). Finally, the precision and accuracy to which oxygen can be analyzed in titanium do not compare with the relative precision and accuracy common to strength measurements.

The work of Rosenberg and Panis (Ref 26) on the 'Ii-xAl-2Mo system (xvaries from 4 to 6%) gives some evidence that both aluminum and oxygen can exert influences on toughness independent of strength. These authors, however, did not employ recrystallization annealing, which should minimize formation of Ti3AI in the continuous alpha which dominates the toughness properties. For the recrystallization annealed condition, the continuous alpha is regrowth alpha, which is low in both aluminum and oxygen; the solute-rich alpha in which Ti3AI can form is thus isolated at the core of each primary grain.

Whateverthat situation, the data of Ferguson and Bertyman (Ref25) on the oxygen effect are given in Fig. 7. In essence, if high fracture toughness is required, oxygen must be kept low, other things being equal. Reducing aluminum, as in Ti-6A1-4V ELI (extra-low interstitial), isalso indicated, buttheeffectisnot asstrong asitisforoxygen(Ref26).

The effect of chemistry on Kb for Ti-6A1-4V was shown in another way by Cooper (Ref 27), who summed the expected changes in the p transus temperature, AT, with alloy additions, and correlated that with Kh. He found a negative effect of ATon Kb, Since oxygen and aluminum additions have the effect of increasing AT, the data are consistent.

The effect of oxygen on KI, is not limited to alpha-beta alloys at ambient temperatures. Van Stone and his coworkers (Ref 28 and 29) reported a much higher Kb value for T1-5A1-2,5Sn ELI (which has a low oxygen content) than for the standard grade in the temperature range from -253 to +22 *C (-423 to +72 OF). Slow cooling of Ti-5A1-2.5Sn ELI from the solution temperature was found to decrease Kb, whereas this effect of cooling rate was absent for the standard grade. Van Stone attributed the change in toughness to a change in deformation mode morphology. The combination of ordering and normal interstitial content did not significantly change the slip character, whereas ordering in ELI plate resulted in coarser slip bands.

As might be expected, hydrogen also has an effect on toughness. The work of Meyn (Ref30) shows that very low hydrogen contents (less than about 40 ppm) enhance toughness. This effect is particularly dramatic with hydrogen contents below 10 ppm. Table 7 illustrates the essential results for Ti-6A1-4V at two different oxygen levels. Meyn used a high

- 501 . 1 . I . I . , . I . I . I .I" 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 0.22

Oxygen content, %

Fig. 7 Influence of oxygen content on h r e toughness ofrecrystallization annealed alloy 'K-6A1-4V, Source: Ref 25

Table 7 Effect of hydrogen content on room-tomprmtun K,4c In ai- loy TWAI4V after fumaco coollng from 927 "C (1700 ' F )

AtOJ6wt4b oxygen 8 36 53 122 At 0.05 wt % oxygen 9 36 50 I25

145 132 118 107 104 95 100 91

133 121 125 I14

101 92 96 m

Tabk8 Relationihlpbohveen Kbandlrootionoftransfonnedstruo tun In alloy TMAI-4V

Beat trentlnp FmeWon d tem#ratura(a) tRMfOrmtd K,.

oc O F atmturaJb hfhJm(b) hidin. la50 1922 loo 69.0 (69.9) 64 950 1142 70 61.5 (60.4) 55 850 1562 20 46.5 (44.6) 40 750 1383 10 39.5 (41.5) 38

(a) Heated for 1 h at indicated ternpereture and then air cooled. (b) Wues in pa- rentheees calculated horn linear leestgpuares erpresaion relating % tranafoma- tion to 4. burce: Ref99

loading rate. However, the effect of hydrogen content on Kb has been confirmed by Chen (Ref 3 1). The work of Chesnutt et al, (Ref 32) on hydrogen effects with nonvalid Kb tests shows the same trend; in this study, however, the hydrogen effect may have depended on microstructure.

Effects of Microstructure. Improvements in Kk can be obtained by providing either of two basic types of microstructures: (a) transformed structures, or sfructures transformed as much as possible, because such structures provide tortuous crack paths; and @) equiaxed structures composed mainly of regrowth alpha that have both low dislo-

Titanium Alloys Fatlgue and Fracture I191

Table 9 Etlsct of primary alpha dbpsrskn on rC, for alloy MI- 25n-4MoO.581 (IM1550) M a )

dm, LIlI m 4 m lc] win. 7.58 593 (59.2) 54 5.83 62.9 (62.3) 37 3.78 63.1 (6.5.9) 60 2.50 67.4 (63.1) 62 3.71 67.5 (66.0) 64 2.26 67.8 (68.6) 62 I .% 71.1 (69.1) 63

(a) W-mm plate heated br 1 hat 900 ‘c (1862 ’F) and air cooled, then heated fbr 24 h at WO OC (Saz Wand air cooled. (b)d is mean phase boundary htarmpt db tame. (c) Val- in pu’8ntbewa were c d c u b d from the linear h a a h q w e e ex- @n relatingK1, to d. &urea: Refs

Kl”

Tabk l o E M offorglng pmcsdure on fracturetoughness of dky TldA158nStrdMo

Kk ForriantemwntPre MPns‘rn (c) Win 55 “C(100 ‘p) bIowkts transus 41,40 37,36 4 o o c (7O’F) above betamus 71,72 65,66

Note: Heatad for 1 hat 88B ‘c (16aS OF) and air cooled,thenbeated for 8 hat 696 oC(1100op)andaircooled.sourcS:Ref32

cation densitim and low concentrations of aluminum and oxygen (the so-called “reaystallization annealed” structures). It is not yet known (in 1994) whether or not combinations of these two types of structures would further enhance Kk values.

TransfomKd structures appear to be tough primarily because frac- Ws in such structures must proceed along tortuousl many-hceted crack paths. According to the work of Hall and Hammond (Ref 33), KI, is proportional to the fraction of transfonned microstructure in alloy Ti- 6A1-4V (see Table 8). These authors, however, propose that it is strain induced transformation of the retained laths of beta phase that leads to enhanced fracture toughness. Evidently, their idea is that th is ‘ n I P ” mechanism enhances “ductility” in front of each crack tip. However, in comparing beta alloys defwmed by either slip or ‘TRIP’ mechanisms, Wardlaw et al. (Ref 34) could find no advantage in ductility for the ‘TRIP” alloys. Cuds and Spurr (Ref 35) suggested that it is primarily the alpha platelet size and efiicient dispersion of the beta phase that enhance toughness. In any event, the work of Chesnutt and Spurling (Ref 11) provides direct evidence that crack tortuosity is an important factor in determining the form of fracture topography-microstructure cone- lations for the same sample. Hall and Piace (Ref 36) made similar ob- servations concerning microstructuns for alloy Ti-6Al-6V-2Sn. Hall et al. (Ref 37) recommended that, for the best combination of fracture toughness and tensile ductility in Ti-6A1-2Sn-4Zr-6Mol a microsmrc- hlre containing 10% primary alpha be employed. There is strong evidence that crack tortuosity is an important variable affecting Kk.

Rogm (Ref 9) looked at the toughness relationship in another way. The alloy be studied was IMI550 (Ti4A1-2Sn4Mo-0.5Si) that hadbeen heated for 1 hat 900 O C (1625 T) and air cooled, then heated for24 h at 500 O C (932 OF) and air cooled. His data show that an increase in the mean phase boundary intercept distance between primary alpha and transfonned microstructure diminishes fracture toughness. Rogers’ data are presented in Table 9. wheshw this relationship holds true for all alpha-beta titanium alloys is not kuown. Rogers’rationale is that, because crack loci and void formation tend to occur at the interfaces between alpha and transformed beta, then a h a s e in the distance between phase boundaries c~uses an increase in the spatial frequency of microvoid formation so as to make blunting and amsting of aacks more likely.

In a similar vein, M e r i c h and Baker (Ref 38) proposed that a proper balance between platelet thickness and spacing in the transformed microstructure is required to achieve highest toughness. platelets need to be thick enough to turn a crack while being spaced such that

Gremtield and Margolin (Ref 39) studied a complex experimental alpha-beta alloy for which shmgth was held constant in both equiaxed alpha and transformed rniaostnrctural conditions. For the equiaxed al- phadata, toughness increased withbetagrainboundary areaperunit volume. For the transformed condition, the data showed that toughness increased with grain boundary alpha t h i c b s s up to about 5.5 mimns, after which fracture toughness revealed no further increase up to an alpha thickness of 10 microns. It must be recognized that the observed fracture surface occurred during catastrophic crack propagation. This implies that the features which gave rise to increased tomusity operated at the onset of catastrophic failure. It may well be that the pmeasea involve crack blunting either by entering the grain boundary alpha along which crack propagation took place or by increasing the amount of plastic defonnation required before the crack would propagate. Since alpha is usually the softerphase the effect of closer alpha spacing (Ref 9) may have been to permit greater deformation before the aack could propagate. In ordcr to understand the particular prcrcesses that affect fracture toughness in a given alloy, it is necessary to observe the interaction between the crack and the microstructure at various stages preceding catastrophic m k propagation.

In any case, beta forging can be substituted forbeta heat treating. See Chesnutt et al, (Ref 32) for data on alloy ?F-6Al-2Sn-42MMo, Penak (Ref 40) for data on alloy TidA14V. ULitchny et al. (Ref 41) for data on alloy 1-6AMV-2Sn, and Chesnutt et al. (Ref 42) for data on all thm of these alloys.TheresultsofChesrmttetal, (Ref32) mpresentedinTable 10. CurtisandSputr(Ref35)teportedasimilareffectofrollingtempera- ture on Ti-6AI-4V; beta rolling enhances K I ~ . Chesnutt et al. (Ref 43) and Bertyman et al. (Ref441 presented similar results for the experimental alpha-beta alloy Corona 5 (*I*1-4,5Al-5Mo-lSCr). Bohanek (Ref 45) demonsmted the same effect of transformed structure enhancement of toughness in TidAl-4V billet. He also showed that this effect does not necessarily carry through to a forged part.

Because welds in alloy Ti4A14V will contain transformed products, one would expect such welds to be relatively high in toughness. This is, in faa, tbe case, as the data of Ferguson and Berryman (Ref 25) show. Their data are summarized in Table 1 1

Grain size apparmtly is not always a definite variable. Margolin et al, (Ref46) showed that toughness first decreased, and then increased, as

tWlSiW3frequent

192 /Titanium Alloy Fatigue Data

Table 12 E M of test direction on mechanical prop8rtles of textured libAI-2Sn-41rbMo plate

Kk 'Itnrile yield Ebnga- Reduclbn Elastic specimen

lest strength, sti-notk tioa, in a m , modulus, K* Orkn- direEtkn(a) MPa MPa % 56 GPs MPaim bidin, tation L 1027 952 11.5 18.0 107 75 68 L T T S

1358 I 200 11.3 13.5 I 3 4 91 a3 L*T 938 924 6.5 26.0 104 49 45 S-T

(a) High basal pole intanuities reported in the traneveree d k d o n , 90° fmm normal, and also intensity nodes in positions Go from the longitudinal (rolling) diRction and about 40° €rum the plate normal. Source: Ref 48

beta grain size decreased in equiaxed Ti-5.25A1-5.5V-0.9Fea.5Cu at a yieldstrengthof 1240MPa(l80ksi), whereasat 1140MPa(165 ksi)the toughness of the same equiaxed alloy decreased continuously with decreasing grain size (Ref 39). Mahajan and Margolin (Ref 47) also showed that cracks tend to develop at interfaces between primary alpha and transformed beta and along slip bands in alpha on surfaces of Ti- 6A1-2Sn-4Zr-6Mo.

Recrystallization annealing is a very efficient method of obtaining high fracture toughness. Also, the relatively precise temperature control necessary to limit primary alpha to a low volume fraction is not needed. As discussed above, arecrystallization anneal is effected simply by heating to a temperature about 70 'C (1 26 OF) below the transformation temperature, holding for a time sufficient to reach equilibrium, and then cooling slowly to about 700 OC (1 300 OF). A transformed structure is thereby completely avoided; the resulting microstructure is nearly free ofdisiocations, and it is this characteristic that justifies the twm "recrystallization anneal." This procedure is well established for the Ti-6AI-4V ELI alloy, and typical data for the recrystallization annealed alloy are shown in Fig. 7. The slow cooling should be terminated at about 700 "C ( I 300 OF) to avoid ordering and Ti3AI formation. This is less important for the ELI grade than for the standard grade.

A real virtue of the recrystallization annealed microstructure is that substantial toughness is achieved while maintaining ductility and fatigue resistance at high strength levels. Such a microstructure also tends to reduce scatter in the data, thus permitting higher design criteria.

Effects of Texture. Effects of texture arise from preferred crystallographic orientation in the material of interest. With all c axes of the alpha grains tending to lie along one (or a few) direction(s) in the product, the physical and mechanical property values necessarily will depend on the direction in which they are measured. Toughness is no exception. The effects that crystallographic texture can have on properties of Ti- 6AI-2Sn4Zr-6Mo (Ref 48) are shown in Table 12. Table 12 is not typical ofmillor forgedproducts; thedataaregivenonly forillustration.TheTi- 6A1-4V alloy shows similar behavior (Ref 49 to 53). Harmsworth (Ref 54) gives similar data for Ti-6A1-6V-2Sn.

Tchorzewski and Hutchinson (Ref 53) showed that effects of alpha phase crystallographic texture can ovemde effects of microstructure and grain size in Ti-6A1-4V. They found that texture affects both the onset of crack extension and the maximum load sustainable in the presence of a fatigue crack. Moreover, texture was found to influence the shape of the plastic zone ahead of the crack. Finally. these authors concluded that the conditions for plane strain fracture may be more stringent in materials having certain textures than in isotropic materials; this remains to be VCrified.

Toughness directionality is not restricted to alpha or to alpha-beta alloys. Williams et al. (Ref 55) demonstrated that toughness in near-beta alloys is a directional property. In this context, near-beta alloys are those alloys in which primary alpha is the minor phase, Such alloys commonly contain beta-stabilizing additions of 8 wt% or more.

Because the basic crystallographic texture arises during hot working operations and cannot be entirely eliminated by heat treatment, there are no known methods of producing wrought titanium p m s having completely random texture and thus zero directionality. However, by balanc- ing the hot working operations as much as possible along all three refer-

ence axes, it is possible to reduce directionality to acceptable levels. But every part is different, and it has become usual practice in the aerospace industry for critical parts to be qualified by the fabricator. On the other hand, by tailoring the alpha phase crystallographic texture to a specific need-say, modulus along a fiber axis-texturing offers a significant potential for enhancing properties. In practice to date (1980), attempts to develop specific textures have been somewhat inconsistent. Paton et al. (Ref 56) suspect that textured material may have increased susceptibility to environmental effects in specific directions.

Effects of Environment. Effects of temperature on toughness are usually less abrupt for titanium than for common low-alloy steel. For example, Tobler (Ref 57) reported a gradual KI, transition temperature between - I96 and - 143 "C (-320 and -2 15 OF) for recrystallization annealed Ti-6A1-4V ELI. For temperatures at and above -143 "C (-215 OF), his Kk values wexe typically about 90 Mpa . G ( 8 2 ksi - G), At -1% "C (-320 "D, his values were typically 60 to 65 M P a G ( 5 5 to 60 k s i a ) . The loss is about 30%. The early conclusion by Christian and Hurlich (Ref 58) that Ti-6A1-4V ELI may be used to cryogenic temperatures thus has some justification. The same may not be tiue of standard grade Ti-6A14V. Tobler's product contained 62 ppm hydrogen, whereas that of Christian and Hurlich contained 70 to 100 ppm. Other authors who have provided temperamdependent toughness results for alloy 'lf-6AI-4V are Cervay (Ref 59) and Hall et al. (Ref 60).

Van Stone et al. (Ref 28) found no significant Kk transition temperature for Ti-5A1-2.5Sn ELI at temperatures down to -263 "C ( 4 2 OF). Values for KI, did decrease with temperature, however.

Chait and Lum (Ref 61) determined the toughness trend (Charpy energy per unit area) with temperature for V-6A1-6V-2Sn. Because of the rich beta content, their low-temperature toughness values were quite low. There was no sharp transition temperature. The toughness vs temperature curve had a simple "S' shape over the temperature range from -196 to +377 "C (-320 to +700 OF). Hannsworth (Ref 54) reported KIc data for alloy Ti-6Al-6V-2Sn over the temperature range from -54 to +93 O C (-65 to +200 OF) the trends of which wece in agreement with those of Chait and Lum,

In aerospace applications, there is a natural concem that chemical environmental factors such as water, salt water, or jet fuel will alter toughness in critical components. Data obtained at McDonnell Aircraft (Ref 62) on annealed standard grade Ti-6A1-4V indicate the following environmental effects on the apparent value of fracture toughness:

Laboratory air, 56 M P a K (51 ksiG) JP4 fuel, 47 MPaG(43 k s i K ) 3.5% salt solution, 34 MPaG(31 ksi&)

The results obtained by Ferguson and Berryman (Ref 25) and by Hall et al. (Ref 60) are similar in that salt water degrades Kk. The early results of Hatch et al. (Ref 63) also showed that salt water can degrade crack growth resistance even in thin sheet where plane strain conditions do not exist, These authors also found significant alloy effects on crack growth in salt water.

Curtis and Spun (Ref 35) charted the effects of quenching temperature on K1, and K I ~ ~ (3.5% salt solution) for alloys Ti-6A14V and Ti- 4A1-3Mo- I V. The KI, and Klscc curves parallel each other for each alloy.

Next Page

Commercially Pure and Modified Titanium Commercially pure titanium has been available as mill products

since 1950 and is used for applications that require moderate strength combined with good formability and corrosion resistance. Prcduction was developed largely because of aerospace demands for a material lighter than steel and more heat resistant than aluminum alloys. How- ever, commercially pure titanium is very useful when high corrosion resistance and good weldability are desired.

Commercially pure titanium is available in several grades, which have varying amounts of impurities such as carbon, hydrogen, iron, nitrogen, and oxygen. Some modified grades also contain small palladium additions (Ti-0.2 Pd) and nickel-molybdenum additions (Ti-0.3Mo- 0.8Ni). These alloy additions allow improvements in corrosion resistance andlor strength.

Commercial purity titanium generally has more than l000ppm oxygen and iron, nitrogen, carbon, and silicon as principal impurities. Be- cause small amounts of interstitial impurities greatly affect the mechani-

cal properties of pure titanium, it is not convenient to distinguish between the various grades of unalloyed titanium on the basis of chemical analysis. Titanium mill products are more readily distinguished by mechanical properties. For example, the four ASTM grades of unalloyed titanium are grouped as follows:

Minimum 0.2 % tensilestrennth yield shenpth

ASTM grade M h kSi MPa hi Gmde 1 240 35 170-310 25-45 Grade 2 345 50 275-450 4065 Grade 3 449 64 380550 55-80 Grade 4 550 80 480655 70-95

Density. 4.51 g/cm3 (0.16 3 Ib/in.3)

Unalloyed titanium is available as four different ASTM grades, which are classified by their levels of impurities (primarily oxygen) and the resultant effect on strength and ductility. ASTM Grade 1 has the highest purity, lowest strength, and best room-temperature ductility and formability of the four ASTM unalloyed titanium grades.

ASTM titanium Grade 1 should be used where maximum formability is required and where low iron and interstitial contents might enhance corrosion resistance. It exhibits excellent corrosion resistance in highly oxidizing to mildly reducing environments, including chlorides. Grade 1 can be used in continuous service up to 425 “C (800 OF) and in intermittent service up to 540 OC (lo00 OF). In addition, Grade 1 has good impact properties at low temperatures.

Chemistry ASTM Grade 1 titanium has impurity limits of 0.18 0,0.20 Fe, 0.03

N, and 0.1OC wt.% max. Equivalent compositions from other specifications are best determined by mechanical properties, because small variations in interstitial contents may raise yield strengths above maximum permitted values or lower ductility below minimum specifications.

Hydrogen content as low as 30 to 40 ppm can induce severe hydrogen embrittlement in commercially pure titanium (see the section “Hy- drogen Damage” in this datasheet).

Product Forms and Condition Unalloyed titanium Grade 1 is available in all wrought forms and has

the best formability of the four ASTM grades. Like the other unalloyed titanium grades, Grade 1 can be satisfactorily welded, machined, cold worked, hot worked, and cast.

Unalloyed titanium typically has an annealed alpha structure in wrought, cast, and P/M forms. The yield strength ofGrade 1 is comparable to that of fully annealed 304 stainless steel.

Applica tions Qpical uses for Grade 1 titanium include chemical, marine, and

similar applications, heat exchangers, components for chemical p m - essing and desalination equipment, condenser tubing, pickling baskets and anodes of various types. In the chemical and engineering industries, Grade 1 is an ideal material for a wide variety of chemical reactor vessels because of its resistance to attack by seawater, moist chlorine, moist metallic chlorides, chlorite and hypochlorite solutions, nitric and chromic acids. It lacks resistance to biofouling.

Unalloyed tltanium grade 1 and equivalents: SpecMcatlons and composltlons

Speeifkation DesigIE3tioIl DeseriDtion C Fe UNS MOloO 0.03max 0.lmax UNS RSOl20 0.05 0.2 UNS MO I25 0.05 0.2 UNS Mow) 0.1 0.2 ChinS GB 3620 TA- 1 0.05 0.15 Europe AECMAprEN2525 mi AECMAprEN3441 mi AECMAprEN3487 mi

Sh Sfrp 0.08 0.2 Sh Sup Ann HR 0.08 0.2 Sh Strp Ann CR 0.08 0.2

A N 0 0.005max 0.012max 0.1 max 0.008 0.02 0.1 0.008 0.02 0.1-0.15 0.015 0.03 0.18

0.015 0.03 0.15

0.0125 0.05 0.2 0.0125 0.05 0.2 0.0125 0.05 0.2

SI OE OT Other balm baln balm baln

0.1 baln

0.1 0.6 balm 0.1 0.6 baln 0.1 0.6 balm

Fl-Ma

AIR9182 T-35 Sh Strp 0.08 0.12 0.0 1 0.05 0.04 balm

(continued)


Unalloyed ttbnfum grade 1 and equivalents: Specifications and c o m p o e b s (continued)

-nY DIN 17850 DIN 17850 DIN 17860 DIN 17862 DIN 17863 DIN 17864

Jaw m class 1 m H4600 m H m n s H W JISH4630 JISH4631 JISH4631 ILP H4650 JIs H4670 Buarla

OST 1.90013-71 UK BS 2TA.I DTD5013 USA A M S 495 1E

ASMESB381 AS'IM 8265-79 ASTM 8337.87 ASTM 8338-87 ASTM 8348.87

ASME SB-265

ASTMB381.67 ASTM F467-84a ASTM F467M-84b ASTMF468-84a AS'IM F468M-W

AWSAs.1670 AWSA5.16-70 AWS AS. 1670

A m F67-88

MIL T-8 15% MILT-81915A MILT-90461

3.7025 Ti1 3.7025 3.7025 3.7025 3.7025

Plt Sh Strp Rod Wir Frg Ann Sh SmPlt Rod WirFrrr Ann Sh Sup Rod wire Fg

Ticlass 1 TP28WC C l r s 1 TR28HE class 1 TTP28DIE Class 1 'ITP28WfWD Class 1 'ITH28DQasd 1 IT-UBW/WD Class 1 TB28CA Class 1 Tw28class 1

Weld el weld el

All forms

VT1.00

2TA.l

WS 495 1 Tiolsde 1 F- 1 XGradel nGrade1 mOrade1 TlOradel F- 1 l M 1 Tioradel Tiorade 1 TiCirade 1 TiCMe 1 ERn. 1 ERn.2 ERm-3 cP4

CP4

HR CR Sh HRCRStlp SmIs Pipe As-wcldhveld L drawn pipe Smh tube for heat exch Weld tube for M a c h HWCDBar WKe

Sh Plt Strp Foil Rcd Fg Ann

Sh Sap HT Bar BiI

Fill met *met W arc weld Sh Sap Plt Ann %Ann Sh Sap Plt Ann Weld smls pipe Ann Smls weld tube Exch Conds Ann Bar Bil AM RgAnn Nut Metric Nut Bolt Saew Stud M c Bolt Screw Stud Sum imp HW CW Frg Ann Mld fill met Weld fill met Weld till met ExtBarShapAnn Invest cast Sh Srrp Plt Ann

0.08 0.08 0.08 0.08 0.08 0.08

0.12 0.03 0.1 0.03 0.05 0.05 0.05

0.08 0.1 0. I 0. I 0.1 0.1 0.1 0. I 0.1 0.1 0. I 0.1 0.1 0.03 0.05 0.05 0.08 0.08 0.08

a2 0.2 0.2 0.2 0.2 0.2

0.2 0.2 0.2 02 0.2 0.2 0.2 0.2 0.2

0.006 0.008 0.3 0.01 0.3 0.3 0.2

0.2 0.2

0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0,2 0.2 0,l 0.2 0.2 0.2 0.2 0.2

0.013 0.013 0.013 0.013 0.013 0.013

0.015 0.0 13 0.013 0.015 0.015 0.015 0.015 0.015 0.015

0.04 0.04 0.015 0.04 0.01 0.01 0.008

0.01 0.013

0.W 0.015 0.015 0.015 0.015 0,015

0.01-0.0125 0.015 0.0125 0.0125 0.0125

0.05 0.05 0.05 0.05 0.05 0.05

0.05 0.05 0.05 0.05 0.011 0.05 0.05 OM 0.05

0.12 0.15 0.04 0.15 0.04 0.04 0.04

0.05 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0,05 0.05 0.05

0,0125 0.05 0.0125-0.015 0.03

o m 0.012 0.008 0.02 0.008 0.02 0.015 0.05 0.015 0.05 0.015 0.05

0.1 0.1 0.1 0.1 0.1 0.1

0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15

0.1

0.15 0.15 0.15 0-15 0.1

0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.1 0.1

0.14.15 0.15 0.2 0.15

balm balm balm baln balm balTi

balm

balm balm balm balm b a l l baln baln

baln

balm balm

0.15 baln balm

0.15 b a l l 0.15 WTi 0.08 0.1

Ti 99.78 min; baln

0.6 balTi 0.1 0.4 balm 0.1 0.4 ball7

0.4 bdn

0.4 baln 0.4 bdTi 0.4 balm

baln bal n baln tells

0.4 baln

baln

baln beln balm

0.3 baln 0.6 baln 0.3 bdTi

SpeeitbtbO Drsinnstbn Descdptbn C Fe H N 0 S i O E O T O t h e r

Unalloyed tttanium grade 1 composttions: Producer speclfkations

SpeeMptkn Desipnrtbn Description C F e H N 0 Si OE OT Other

Germnny DeutscheT Coniimt 30 Sh Sap Plt Bar WuFrg Pip 0.06 0.15 0.13 0.05 0.12 FuchS T2 Frg Jam

Kobe KS40 Sh Sap Tu PIt WBar Pip Ann 0.1 0.01 0.03 0.1 0.m 0.01 a03 0.1 0.1 0.01 0.03 0.08

Kobe KS40LF Wkgnde Kobe K W AM Kok W50 AM 0.15 0.01 0.03 0.15 Kobe KS5OI.F LowFegmle 0.05 0.01 0.03 0.15 s u m i m ST-40 UK

Daido DT1 Rod Bar Sh Sap Frg Ann 0.1 0.2 0,0125 0.03 0.18

bdn

balm bal baln bal Ti bal Ti baln

IMI 110 Rod n s9.a m. IMI 115 All Pm 0.1 0.2 0.013 a03 0.15 ban Imp Metal

(continued)

Commerelally Pure and Modwed Tlteinlum I207

Unalloyed tftanlum grade 1 comporttknr: Producer rpeclficatlons (conthued)

SpsfMcstka Desirnstbn Dacrlprion C Fe H N 0 81 OE OT Othw

USA chaw Exf. CDX GR- 1 ORFMET TI. 1 RMI RMI 25 Chemicaumarindaimamappr 0.08 0.2 0.01s 0.03 0.18 TellodneY A35

baln

TlMET TIMETAL3SA Ann 0.1max 0.02max 0.1Smax 0.03max 0.18max balm ma Ti- I

Grade 2 titanium is the”workh0rse” for industrial applications, having a guaranteed minimum yield strength of 275 MPa (40 h i ) and good ductility and fonnability. The yield strength of Grade 2 is comparable to those of annealed austenitic stainless steels, and it is used where excellent formability is required and where low interstitial contents might enhance corrosion resistance.

Grade 2 also has good impact properties at low tempatures and excellent resistance to msion and b corrosion by seawater and marine at- mospheres. Grade 2 can be used in continuous Service up to 425 OC (800 OF) and in intermittent service up to 540 ‘C (loo0 OF).

Chemistry ASTM Grade 2 titanium has the same nimgen content limits as

ASTM Grade 1 (0.03% max), the same iron content limits as ASTM Grade 3 (0.30% ma) , and a maximum oxygen concentration of 0.25% that is approximately midway between the 0.18 to 0.40% range in the other three ASTM unalloyed titanium grades.

E f k t oCImpuritZea The increased iron and oxygen concentrations of ASTM Grede 2 co-d to ASTM Grade 1 impart additional tensile strength (345 vs 240 MPa, or 50 vs 35 h i ) and yield strength (275 vs 170 MPa, or 40 vs 25 ksi) to Grade 2 but at the expense of ductility (20% elongation for Grade 2 vs 24% elongation for Grade 1). Higher iron and interstitial contents also may degrade corrosion resistance relative to orade 1.

Hydrogen content as low as 30 to 40 ppm can induce hydrogen embrittlement in CP titanium (see the section ‘Wydrogen Damage“ in this datasheet).

Product Forms and Condition Titanium Grade 2 is available in all wrought product forms. In cast

form, ASTM Grade 2 constitutes about 5% of cast titanium products. Like 0 t h unalloyed titanium grades, Grade 2 can be welded, machined, cast, and cold worked.

ntanium Grade 2 typically has an annealed alpha stnrcturr: in wrought, cast, and PA4 forms. It is not heat treatable.

Appilca tions Typical uses for titanium Grade 2 include chemical, marine, and

similar applications, airframe skin and nonstructural components, heat exchangers, cryogenic vessels, components for chemical processing and desalination equipment, condenser tubing, pickling baskets, anodes, shafting, pumps, vwsds, and piping systems. Grade 20ffers highductil- ity for fabrication and moderate strength in m i c e .

Airanft applicatlons include exhaust-pipe shrouds, fveproof bulkheads, gas-turbine bypass ducts, hot-air ducts, engine cowlings, formed brackets and skins for hot areas. Other aircraft applications include gal- ley equipment, chemical toilets and floor supports under these ams.

Reaction vessels and heat exchangeers are a major application of orade 2 titanium because of its resistance to a m k by seawater, moist chlorine, moist metallic chlorides, chlorite and hypochlorite solutions, nitric and chromic acids, organic acid, sulfides, and many industrial gaseous environments. Grade 2 titanium also has excellent resistance to deposit, impingement, and crevice attack even in highly polluted waters, andis therefore used extensively in tubularsndplate-typeheat exchangers for condensers, evaporators, and other components of marine VCS- sels, power stations, oil refineries, offshore platforms, and water-purifi- cation plants.

Electrochemical R.ocessing Equipment. The insulating property of the anodic film on titanium makes it an ideal and cost-efficient material for anodizing jigs and plating baskets. Other applications include high-efficiency heatexchanger systems for electrolytes. A very thin coating of a precious metal such aa platinum enables Grade 2 titanium anode to operate at high current density in many electrolytes. Conse- quently, non-consumable noble-metal coated Grade 2 titanium modes are in demand for chlorinegroduction cells, electrodialysis plants, elec- troplating equipment, and cathodic protection of condensers, seagoing rigs, and jetties.

Most elecwdeposits do not adhere. well to commercial purity Grade 2 titanium. This characteristic has led to the widespread use of Grade 2 titanium for cathodes or starter-sheet blanks in many electrochemical metal-refining operations.

Unalkved thanlum ondb 2 snd eaulvalents: Swoiflwtlons and comwaltlonr

8W-W Dalrnatbn Dolerludon C FB E N 0 81 OE OT Other UNS R50130 0.05 a3 0.008 0.02 0.1s-0.25 balm UNS RSo400 0.1 0.3 0.01s 0.03 0.25 balm

QB 3620 m-2 0 . l m 0 . 3 m O.OI5max 0.05max 0 . 2 ~ 0.1Snw balm Eumpe

AECMAprEMS26 n-w2 sh sap 0.08max 025m O.OI25max 0,OSmax 0.25max 0.1max Odmax WTi

China

AECMApEN2518 m m 2 Sh Sap Bar om 0.2 0.01 0.06 0.25 06 brln

(continued)


Unalloyed tltanlum grade 2 and equivalents: Spaeiflcations and compositions (continued)

Speciflcntion Designation Description C Fe H N 0 Si OE OT Other

Europ (continued) AECMAprEN3378 A E M prEN3442 AECMA prEN345 1 AECMA prEN3452 AECMA prEN3460 AECMAprEN3498 France AIR9182 AIR9182

Germany DIN 17850 DIN 17850 DIN 17850 DIN 17850 DIN 17860 DIN I7862 DIN 17863 DIN 17864 WL3.7024 WL3.7034 Japan

Tim Ti-FQ2 Ti-Po2 Ti-Po2 Ti-Po2 Ti-WZ

T-35 T-40

Ti II Tim WL3.7035 WL3.7055 3.7035 3.7035 3.7035 3.7035

Wir Sh Strp Ann HR

Frg Ann BarAnn ShStrpAnnCR

Frg NHT

0.08m 0.2511~ 0.0125max 0.05max 0.25 max O.(#Lmax 0.2.5mar 0 . 0 1 2 5 m 0,OSmax 0,25max 0.08max 0.25 max 0.0125max 0.05 IIU 0.25max 0.08 l ~ w x 0.25 m 0.0125max 0.0511~ 0.25max 0.08max 0.25 m u 0.0125max 0.OSrrmx 0.25 rrm 0.08mnx 0.25 max 0 . 0 1 2 5 m 0.05max 0.25max

0.1 max 0.6rnnx balm 0.1 mu 0 . 6 m balm 0.1 msx 0.6max bJTi O.lmaxO.6max MTi 0.1 max 0.6max balm 0.1 max 0.6max balm

Sh CR Sh

0.08 0.12 0.015 0.05 0.08 0.12 0.015 0.05

0.04 0.04

Ti 99.69 rnin Ti 99.69 min

bal Ti bal Ti bal Ti balm baln bal Ti baI Ti baln bal Ti bal Ti

bal Ti WTC balTi balm baJ Ti bal Ti bal Ti bal Ti bal Ti

bal Ti W0.2baln

bal Ti balm

TiW.78 min Ti 99.78 min n 99.79 min 77 99.78 m h

bal Ti

bal Ti bal TI balm bal Ti bal Ti bal Ti bal Ti balm bal TI balm balm balm bal Ti balm bal 'TI bal Ti bal Ti bel Ti bal Ti balm

Sh Strp PI1 Rod Wu Frg Ann ShStrpPlt RcdWirFgAnn Plr Sh Snp Rod Wir Frg Ann Sh Plt hrp Rod Wir Frg Ann Sh Snp Rod Wir Frg Sh Wir AM Sh BiuFrg WrAnn

0.08 0.25 0.1 0.3 0.08 0.25 0.1 0.3

0.08max 0.25max 0.08rnnx 025 mnx 0.08 max 0.25 max 0.08 max 0.25 m

0.013 0.013 0.013 0.013

0.013max 0.013 max 0.013 max 0.013 w

0.0125 0.0 1 25

0.015 0.0 I5 0.0 I3 0.013 0.015 0.015 0.01s 0.015 0.015

0.0 1 0.015

0.0 125 0,0125

0.01 0.0 1 0.0 I 0.01

0 . 0 1 5 ~

0.015 0.015 0.0 1 5

0.06 0.2 0.06 0.25 0.06 0.2 0.06 0.25

0.06max 0.2 max 0.06max 0.2max 0.06max 0 . 2 m 0.06rnaX 0.2max

0.6 0.6

0.08 0.08

0.07 0.15

0.08 0.08

0.2 0.25

0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25

0.3 0.3

0.2 0.25

0.2 0.2 0.2 0.2

0.05 0.06

0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05

0.04 0.05

0.05 0.05

0.05 0.05 0.03

0.2 0.25

0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2

0.2 0.2

0.2 0.25

0.2 0.25 0.25

Class 2 I T H 35D Class 2 TP35 H/C Class 2 TR 35 H/C Qass 2 lTP35 DiE Class 2 l T P 35 W N D Class 2 TTH 35 W N D Class 2 TB 3s C/H Class 2 Tw 35 Class 2

JIS H4361 JIS H W JIS H4600 JIS H4630 JIS H46W JIS H463 I JIS H4650 JIS H4670

RUSSie

OST 1 .WJOO-76 OST 1.90060-72 Spain UNE 38-7 11 UNB 38-712 UK BS 2TA.2 BS 2TA.3 BS 2TA.4 BS 2TA.5 DTD SO73 USA AMS49028 AMs4941c

ASME SB-265 ASME SB-381 ASTM B 265 ASTM B 337 ASTM B 338 ASTU B 344 ASTM B 367.87 ASTM B 381 ASTM F467-84 ASTM F467M-84a ASTM F468-84 ASTM F468M-84b

AWSA5.16-70 MlLT-81556A MILT-81915 MILT-90461

ASm 4 w c

ASI'M F67

Srnls Tub Sh HR CR Strp HR CR sml5 Pip Weld Pip WldTub Bar Rod HW CD Wir

VTI-O VTlL

Mull Forms Ann cut

0. I 0.3 0.15 0.3

L-7M)l L -7W

Sh Plt Strp Bar Wir Exf Ann Sh Ph Sup Bar Wir Exr Ann

Sh Strp HT Bar HT Frp, HT Frsm Tub

2TA.3 2TA.4 2TA.5

0.01 IMX 0 . 2 w

Sh StQ Plt Ann WeldTub AM Smls Tube Ann Sh Strp Plt AM Frg Ann Sh Svp Plt Ann PipAnn Tube for hear exchkond BarBilArin cast Frg Ann Nut Nut Met Blt ScrStd Bll Scr Sid Met Surg imp HW CW Frg Ann Weld All Met Ex1 Bar ShD Ann

0.08 0.3 0.1 0.2 0.1 0.3

0.1 max 0.3 W

0.3 0.1s 0.3

0.1 nrax 0 . 4 ~ 0.1 w 0 . 4 m

0.4 0.4

0.4 0.1 max 0.41~.

Ti Grade 2

Ti Grade 2 TI Grade 2 Ti Grade 2 Ti Gnde 2 'I7 Grade 2 Ti Grade F-2 no lade2 Ti Grade 2 Ti Grade 2 T i W 2 Ti Grade 2 ERTi-4 Code CP.3 Type I Comp A Code 42-3

F-2 0.015rnax 0.03 max 0 . 2 5 ~ 0.01Smax 0.01max 0 . 2 5 1 ~ ~ 0.015 0.03 0.25 0.015 0.03 0.25

0.0125-0.01 0.03 0.25 0.015 max 0.0511~ 0 . 4 m

0.015 0.03 0.25 0 . 0 1 2 5 m 0.05mar 0 . 2 5 ~ 0.0125 max 005 max 0.25 max 0.0125 max 0 . 0 5 m 0.25max 0.0125 max 0.05 max 0.25 m

0.0150.0125 0.03 0.25 0.008 0.02 0.15-0.25 0.015 0.05 0.2

0.1 m 0.3mx 0.1 0.3 0.1 0.3

0.1 0.1 max

0.1 0.1 max 0.1 max 0.1 max 0.1 max 0.1 0.05 0.08

0.3 0.2 max 0.3

0.3 max 0.3 max 0.3 m 0.3 max

0.3 0.3 0.3 0.3

0.6 0.3

Air/ch&neappsCasiAnn 0.08 0.2 0.01s 0.05 0.2 Sh Strp Plt Ann 0.08 0.3 0.015 0.05 0.2

Commercially Pure and Modified Titanium / 209

Unalloyed titanium grade 2 compositions: Producer specifications

T if re ti on Desianation Description C Fe H N 0 Si OE OT Other

France Ugine Ugine Germany Otto Fuchs Thyssen Thyssen Japan Daldo Kobe Kobe Nippon Sumilomo Sumiiomo Toho Toho Toho Toho

UK Imp. Metal Imp. Metal USA Chase Ext. OREMET RMI

uT35 uT40

T3 Contime! 35 Contimet 35 D

DT 2 KS60 KS60LF TIX

ST6 TIB TIBLF TIC TICLF

ST-50

IMI 125 IMI 130

CDX GR-2 Ti-2 Rha40

Sh PI! Bar Frg Ann Sh PIt Bar Frg Ann

Frg Sh Strp Pit Bar Wir Pip Ann Mult forms Ann

Rod Bar Sh Strp Frg Ann Sh Strp Tub Plt Wir Bar Pi Ann Low Fe Ann

L O W Fe

Low Fe

Mull forms Sh Bar

Mull forms Ann TeLRodney A40 TIMET TIMETAL 50A AIU TMCA Ti 2

0.08 0.08

0.06 0.06

0.1

0.03 0.02 0.03 0.02

0.1 0.1

0.08

0.25

0.2 0.25

0.3 0.3 0.05 0.5

0.1 0.05 0.15 0.05

0.2 0.2

0.25

0.0125 0.0125

0.013 0.013

0.0125 0.01 0.01

0.005 0.005 0.005 0.005

0.0 13 0.0 13

0.015

0.05 0.2 0.05 0.25

0.05 0.18 0.05 0.25

0.03 0.2 0.03 0.2 0.03 0.2 0.1 0.2

0.015 0.15 0.01 0.15 0.02 0.25 0.01 0.25

0.03 0.2 0.03 0.25

0.03 0.2

0.08max 0.2max 0.0125 m u 0.05 rnax

ball3 bal Ti

Ti 99.5 bal Ti bal Ti

baln MTi balm baln

Ti 99.1 min Ti 99.7 min TI 99.6 min Ti 99.6 min

bal Ti bal TI

bal Ti

bal Ti

Grade 3 titanium is a general-purpose grade of commercially pure titanium that has excellent corrosion resistance in highly oxidizing to mildly reducing environments, including chlorides, and an excellent strength-to-weight ratio. Thus, like other titanium metals and alloys, Grade 3 bridges the design gap between aluminum and steel and provides many of the desirable properties of each. Grade 3 also has good impact toughness at low temperatures.

Chemistry ASTM Grade 3 titanium has lower iron limits than ASTM Grade 4

(0.3 wt% vs 0.5 wt% max) and the second highest oxygen contents (0.35 wt%) of the four ASTM grades for unalloyed titanium. Only Grade 4 has higher strength levels than Grade 3.

Effect of Impurities. Excessive impurity levels may raise yield strength above maximum permitted values and decrease elongation or reduction in area below minimum values. Higher iron and interstitial contents may affect corrosion resistance.

Hydrogen content as low as 30 to 40 ppm can induce hydrogen embrittlement in commercially pure titanium (see the section “Hydrogen Damage” in this datasheet).

Product Forms and Condition Like other unalloyed titanium grades, Grade 3 is available in all

wrought product forms and can be satisfactorily welded, machined, and cast. Most forming operations can be carried out at room temperature but warm forming reduces springback and power requirements.

Titanium Grade 3 typically has an annealed alpha structure for wrought, cast, and P/M forms.

Applications Grade 3 is used for nonstructural aircraft parts and for all types of ap-

plications requiring corrosion resistance. Typical uses for CP titanium include chemical and marine applications, airframe skin and nonstructural components, heat exchangers, cryogenic vessels, components for chemical processing and desalination equipment, condenser tubing, and pickling baskets.

Unalloyed titanium grade 3 and equivalents: Specifications and compositlons

Specifmtion Designation Description C Fe H N 0 Si OE OT Other UNS R50550 0. I 0.3 0.015 0.05 0.35 0.4 bai TI France AIR9182 T-50 Sh Ann 0.08 0.25 0.015 0.01 0.04 Ti 99.54 min

(continued)


Unrlbyedtimnlum grade 3 and aquivaknts: Sp6elflcatlons and compositions (continued)

SwCiAflrtbcl Lhkrmtlon DesfWbn C Fe A N 0 91 OE OT 0 t h

-nY DIN 17854 DIN 17850 DIN 17860 DIN 17862 DIN 17863 DIN 17864

Jaw JIS JJS H a JIS H46W JIS H4630 JIS H4630 JIS H463 1 J 'ISIs31 JIS H4650 JIS H4670 UK BS 2TA.6 BS 2TA.7 BS 2U.8 BS 2TA.9 DTD 5023 DTD 5273 DTD 5283 USA AM349001 AMS4951E ASME SB-265 ASMESB-381 ASTM B 265 ASTM B 337 Asru B 338 AsTMB348

Ti IV wL3.7065 3.7055 Sh Sap 3.7055 Rod 3.7055 W f 3.7055 Frg

Sh Snp P11 Rod WuFrg Ann PLt Sh Sap Rod Wit Frg AM

class 3 TP49 He class 3 ShHRCR T R 4 9 W C h 3 SapHRCR TIP49 D / E C W 3 lTP49WPUDQass3 WeldPip TTH 49 D Class 3 ~ 4 9 W l w o c l a u 3 WeldTub TB49CMCl~ss3 BarHWCD TW49Clarr3 wu

Smls PipHot Ext CD

SmlrTubCD

ShSapHT Barm Rs Frgm Sh Sap Bar w Sh Sap Plt Ann Weld Wir

Grade3 Sh Strp Plt AM F-3 Fg An -3 Sh Sap Plt Ann orade3 Weld SmlsPipAnn olsde3 Smls WcldTubAnn olade3 Bar Bil Ann

A m B 3 8 1 GrsdeF-3 F r g h ASTM B 367.81 C-3 cast ASTMF67 Grade3 surg m MILT-81556A W C P - 2 Ext B a r S h p h MLTM46J W C P - 2 ShSapPltAnn

0.1 0.35 0.1 0.35

0 . l W 03max 0.1 m 0.3max 0 . l m 0 . 3 ~ ~ 0.lmax 0 . 3 m

0.3 0.3 a3 0.3 0.3 0.3 0.3 0.3 0.3

0.2 0.2 0.2 0.2

0.2 max 0.2 max 02 max

0.08 0.3 0.08max 0.2max 0 . l m 0 . 3 m 0.1 max 0 . 3 m

0.1 0.3 0,l 0.3 0.1 0.3 0.1 0.3 0.1 0.3

0 . 1 ~ 0.25max 0. I 0.3 0.08 0.3 0.08 0.3

0.013 0.013

0 . 0 1 3 ~ 0.013 max 0,013 max 0.013mnx

0.015 0.013 0.013 0.015 0,015 0.015 0.015 0.015 0.015

0.01 0.01 0.01 0.015

0,0125 mBX 0.0125 max 0.0125 max

0.015 0.005 max 0 . 0 1 5 ~ 0.015max

0.015 0.015 0.015 0.0125 0.015

0.015max 0.01 5~3.0125

0.015 0.013

0.07 0.3 0.07 03

0.Obmax 0.25maX 0.06maX 0.25max 0.06m 0.25max ao6m 0.25maX

0.07 0.3

0.07 0.3 0.07 0.3 0.07 0.3 0.07 0.3 0.07 0.3 0.07 0.3 007 0.3

om 0,3

0.0s 0.3 0.05max 0.18max 0.05max 0 . 3 5 ~ O D S m 035max

0.05 0.35 0.05 0.35 0.05 0.35 0.05 035 0.05 0.35

0.05 max 0.4max OM 0.35 0.05 0.3 0.05 0.3

0.3 0 . l m 0.6m 0 . 1 ~ O A m 0.1 MV( 0 . 4 1 ~

0.4 0.4 0.4 0.4 0.4

0.1 m 0 . 4 ~

0.3 0.3

baln balm balm bdTl balm WTl

baln W n balm balm balm baln

balm balm

baln

balm wn kill bdn

W n beln balm balm balm balm balm

baln

baln

Unalloyed tbnlum grade 3 compositions Producrr rpeclficatlonr

s # f l f b t i O O k l g n s t b n Jknrriptbn C Fe R N 0 SI OE OT Other

h r w p

U g h UT50 Sh Bar Frg Ann 0.08 0.25 0.0125 0.07 0.35 Germany ThY6Se.n Contim 55 Mult Fcms Ann 0.06 0.3 0.013 OM 035 Titan RT 20 0.1 0.35 0013 0.07 0.3

J a w Daido DT 3 Mult Forms Ann 0.1 03 0.0125 0.05 0.35 Kobe KS70 Ann 0.3 0.0 1 OW 0.3 Kobe KS70LP Low Fe Mult Forms Ann 0,05 0.01 0.05 03 Sumltomo ST-70 Toho m 0,05 0.2 0.01 0.04 a3 UK Imp.Metal IhlllM USA chase Ext. CDX OR-32 OREMET Tim3 RMl RMI 55 Mult Forms AM 0.08 0.25 0.015 0.05 0.3 Tel.Rodnev A55

bpln

beln baln

bpln baln balm

n99.4mia

bd Ti

TIMET TIMETAL65A Ann 0.lmax 0 . 2 m 0.015max 0 . 0 5 m 0.35ma~ baln TMCA n 3

Commercially Pure and Modified Titanlum / 21 1

Grade 4 has the highest strength of the four ASTM unalloyed titanium grades in addition to good ductility and moderate formability. The benefits of strength and lightness of Grade 4 are retained at moderate temperatures. Its strength-to-weight ratio is higher than that of AISI type 301 stainless steel at temperatures up to 315 OC (600 OF). Grade 4 also has outstanding resistance to corrosion fatigue in salt water. The stress required to cause failure in several million cycles is 50% higher for this material than for K-Monel or AISI type 43 1 stainless steel.

Chemistry ASTM Grade 4 has the highest oxygen (0.40 wt%) and iron (0.50

wt%) content of the four unalloyed titanium ASTM grades. The higher content of iron and interstitials may reduce corrosion resistance.

Hydrogen content as low as 30 to 40 ppm can induce hydrogen embrittlement in commercially pure titanium (see the section "Hydrogen Damage" in this datasheet).

Product Forms and Condition Commercially pure Grade 4 is available in all wrought product

forms and can be satisfactorily machined, cast, welded, and cold worked. Most forming operations are performed at mom temperature but warm forming (150 to 425 OC, 300 to 800 OF') is often done to reduce springback and power requirements. Complex forms must be produced by warm forming.

Grade 4 typically has an annealed alpha structure in wrought, cast, and P/M forms.

Applications Because Grade 4 has excellent resistance to corrosion and erosion

applications, it is suitable for a wide range of chemical and marine applications, where it often can be used interchangeably with Grade 3. It can be used in continuous service at temperatures up to 425 OC (800 OF'), and intermittent service to 540 "C (loo0 OF).

Unalloyed tItanlum grad 4 and equivalents: Specifications and composltions

SDeclRcstbn M g n n t b n Descrlptton C Fe A N 0 SI OE OT Other UNS Chlna GB 3620

Europe A m prEN25 19 AECMAprEN2520 AECMA prW2527 A W p r E N 3 4 4 3 AECMA prEN3453 AECMAprEN3461 AECMAprEN3496 AECMAprEN3499 Prpl#p AIR9182 Germany DIN DIN 17860 DIN 17862 DIN 17863 DIN 17864 Spsln

UK BS 2TA6 BS 2TA7 BS 2TA8 BS 2TA9 USA AMS4901L AMS4921F A S " B 265 ASTM B 348 ASTM B 367 ASTM B 367 ASTMB381

UNE38-714

ASTM F467-84 ASTM F468-84 ASTM F67

MIL F-83142 MILT-81556A MILT-W6J MILT-90474 MILT-90470

R50700

TA-3

Ti-Po4 n-Po4 n-Po4 Tim4 Ti-Po4 Ti-Po4 Ti-Po4 Ti-Po4

T-60

3.7064 3.7065 3.7065 3.7065 3.7065

L-7004

Grade 4 otede4 orrtde c-2 Grade c-3 Grade F-4 Grade4 Grade 4 Grade 4

Comp 1 code 8- 1 Codecp-1 SP-70 Ti-CP-70

BarFrgShSnp

Sh Sap Strp Sh Ann CR Frg NHT Bar Ann Frg Ann Sh Snp Ann CR

Frg

ShAnn

Sh Rod Bar Frg Ann Sh Strp Rod wu Frg

Mult Forms AM

Sh Sup Plt Ann Bar Wir Frg Bil Rng Ann Sh Plt Sup Ann Bar Bil Ann Cast Cast FrgAm Nut Blt Scnv Std Sh Strp Bar HR CR Ann Frg

n g A M Ext Bar Shp Ann Sh Strp Plt Ann Bar Bar Bil Ann

0.1 0.5 0.015 0.05 0.4 0.4 baln

0.1max 0.4max 0.015max 0.05max 0.3max 0.15max balm

0.08 0.08 max 0.08 max 0.08 max 0.08 max 0.08 max 0.08 max 0.08 max


0.01-0.0125 0.0125 max 0.0125 max 0.0125 max 0.0125max 0.0125 max 0.0125 max 0.0125 max


0.4 0.4 max 0.4 nmx 0.4 m&x 0.4 max 0.4 max 0.4 max 0.4 max

0.6 0.lmax 0 . 6 ~ 0.lmax 0.6max 0.1 max 0.6max 0.lmax 0 . 6 1 ~ 0.lmax 0 . 6 ~ 0.1 max 0 . 6 ~ 0.1 max 0 . 6 ~

baln baln balm balm balm balm balm balm

0.08 0.3 0.015 0.08 0.04 nB.56 mi0

0.08 0.35 0.0125 0.07 0.4 0.1 max 0 . 3 5 1 ~ 0.013max 0.07max 0.3max 0.1 max 0.35max 0.013max 0.07max 0.3nmx 0.1 max 0.35max 0.013max 0.07max 0 . 3 m 0.1 max 0.35max 0 .013m 0.07max 0.3max

0.1 0.4 0.0125 0.07 0.4 baln

0.08max 0.2max 0.0125max 0.08max 0.2max 0.0125max 0.08max 0.2max 0.01 max

0.2max 0.015max

0.08 0.08 0.1 0.1 0.1 0.1 0.1

0.1 max 0.1 max

0.1

0.08 0.08 0.08

0.08 m8x 0.08

0.5 0.5 0.5 0.5 0.2 0.25 0.5

0.5 max 0.5 max

0.5

0.5 0.5 0.5

0.5 max 0.5

0.015 0.0125 0.015

0.0125-0.01 0.015 0.015 0.015

0.0125 max 0.0125 max

0.015- 0.0 12.5 0.0125 0.015 0.015

0.015 max 0.0125

0.05 0.05 0.05 0.05 0.05 0.05 0.05

0.07 max 0.07 max

0.05

0.05 0.05 0.05

0.05 max 0.05

0.4 0.4 0.4 0.4 0.4 0.4 0.4

0.4 max 0.4 max

0.4

0.4 0.4 0.4

0.4 max 0.4 max

ball7 ball baln balm

0.3 balm

0.4 balm 0.4 baln 0.4 balm 0.4 baln 0.4 baln

balm baln balm

0.3 baln 0.3 baln

0.3msx balm 0.3 Y 0.005;balTl

0.3 baln

0.3 balm

212 I titanium Alloy Fatigue Data

Unatloyed titanium grade 4 commerclai equivalents: Composltions

Swelllation Dealgnation Description C Fe H N 0 si OE OT other

Fmlre Ugine Germany Otto Fwhr Japan Daido Kobe Sumitomo

UK Imp. Melal Imp. Metal USA chase EM. Crucible OREMET RMI TeLRcdnoy TIMET

uT60 Bar Frg Sh PI1 Ann

DT4 KS85

Bar Rod Shp R g Ann Sh Sop Plt Wir Bar Ann

ST-80

IMl155 Sh IMf 160 Rod BY Bil Wir

CDX OR-4 A-70 Ann Ti4 RMI 70 Mull Forms Ann A40 Ti-75A Ann TIMETALIMA Ann TIMET

TMCA Ti 4

0. I 0.35 0.0 I 25

0.1 0.5 0.012s 0.4 0.01

0.1 0.2 0.013 0.1 0.2 0.017

0.05-0. I5

0.08 03 0.015

0.1 max 0.3 ma^ 0.015max 0.01 mar; 0 . 3 m 0.01 max

0.07 0.4

0.05 0.5 0.05 0.4

0.03 0.38 0.05 0.4

0.07 max

0.05 0.4

0.4 m 0 . 0 S m 0.41-m

bal Ti

Ti 99

bal Ti balTi

baln balm

bal Ti

balm

bal TI baln

The two Ti-O.2Pd ASTM grades I 7 and 1 I ) have better resistance to crevice corrosion at low pH and elevated temperatures than that of ASTM Grades I , 2, and 12, and they are recommended for chemical-industry applications involving environments that are moderately reducing or that fluctuate between oxidizing and reducing. The pailadium- containing alloys extend the range of titanium applications in hydrochloric, phosphoric, and sulfuric acid solutions. Their good fabri- cability, weldability, and strength are similar to those of corresponding grades of unalloyed titanium. Ti-0.2 Pd Grade 7 is comparable to Grade 2 in strength, while Grade 1 I is comparable to unalloyed Grade I in strength.

Chemistry A relatively small addition of palladium (0.15 to 0.20 wt%) to unal-

loyed titanium permits its use in stronger reducing media such as mild sulfuric and hydrochloric acids.

The higher oxygen content (0.25 wt%) and higher iron content (0.30 wt%) of the Grade 7 alloy results in lower ductility and cold formability but higher strength than Grade I 1 which has a maximum oxygen content of 0. I8 wt% and a maximum iron contcnt of 0.20 wt%.

Hydrogen content as low as 30 to 40 ppm can induce hydrogen embrittlement in commercially pure titanium (see the section "Hydrogen Damage" in this datasheet).

Product Forms and Condition Both Grade 7 and Grade 1 1 alloys are flat rolled products, extru-

sions, wires, tubing, and pipe. Ti-0.2Pd grades can be satisfactorily cast, welded, machined, and cold worked. Most forming operations arc performed at room temperature, but warm forming (150 to 425 "C, or 300 to 800 OF') is sometimes employed.

Ti-0.2Pd products typically have an annealed alpha structure.

Appiica tions Ti-0.2Pd, Grade 7 and Grade 11 are used for chemical-industry

equipment and for special corrosion applications. These alloys have ex- cellcnt corrosion resistance for chemical processing applications. They are also used for storage applications involving media that are mildly re ducing or that fluctuate between oxidizing and reducing. The palladium- containing alloys are also used where high cold formability in component fabrication is required, such as cold pressed plates for platdframe heat exchangers and chlor-alkali anodes. ASTM Grades 7 and 11 can be used in continuous service up to 425 'C (800 OF) and in intermittent service up to 540 "C (1000 OF).

Ti4.2Pd grades 7 and 11 and equivalents: Specifications and compositions

Speeifmtbn Designation h d p t b n C Fe H N 0 Pd SI OT Other UNS RS2250 Grnde I I 0. I 0.2 0.015 0.03 0. I 8 0.12-0.25 bal Ti CMS RS2JOo Grade 7 0. I 0.3 0.01 5 0.03 0.25 0.12-0.25 bal Ti LMS RS2401 Filler 0.0s 0.2s 0.008 0.02 0.15 0.15-0.25 bal Ti Germany DIN 17851 3.7225 0.06mnx 0.15mru O.WI3mim 0.0Smax O.l?max 0.12p0.25 0.4max balm DIN I785 I 3.7235 0.06m 0.2n-m 0.0013maX 0.OSmu 0.llmaX 0.12-0.25 0.4 max bal Ti DIN 17851 3.7255 0 . M m 0.25 max 0.0013 nw 0.05 mca 0.29mau 0.12-025 0 . 4 1 ~ balm

(continued)

Commercially Pure and Modified Titanium / 21 3

TbO.2Pd grades 7 and 11 and equivalents: Specifications and compositions (COntlnUed)

Swcillrstbn Designation Description C Fe H N 0 Pd si OT other

Japan JIS H 4635 type I 1 JIS H4635 type I I JIS H 4635 type 11 JIS H 4635 type 11 JIS H 4635 type 12 JIS H 4635 type 12 JIS H 4635 type 12 JIS H 4635 type 12 JIS H 4635 type 13 IISH4635type13 JIS H 4635 type 13 JISH4635type13 JlSH4636type 11 JIS H 4636type 11 IISH4636typell JISH4636type 12 JIS H 4636 type 12 JIS H4636 type 12 JIS H 4636 type I3 IIS H4636 type 13 JIS H 4636 type 13 JIS H4655 type 11 JISH4655typell JIS H 4655 type 12 JIS H 4655 type 12 JIS H 4655 type 13 JIS H 4655 type 13 JISH4675typell JIS H4675 type 12 JIS H 4675 type I3 R u i n

Sp in UNE38-715 USA ASTM B 265 ASTM B 265 ASTM B 337 ASTM B 337 ASTM B 338 ASTM B 338 ASTM B 348 ASTM B 348 ASTM B 367 ASTMB381 ASTM B 381 ASTM F467-84 ASTM F467M-84a ASIUF468-84 ASTM F468M-84b AWS AS. 16-70

TTP28PdD TTP28PdE TTP28PdW "28PdwD 'ITP35PdD 'ITP35PdE 'ITP35Pdw TTP35PdwD "P49PdD Tl'P49PdE ITP49PdW m 4 9 P d w D lTH28PdD 1TH28PdW lTH28PdwD TTH35PdD TTH35PdW 'ITH35PdwD 1TH49PdD TTH49PdW m 4 9 P d w D TB28PdC TB28PdH TB35PdC TB35PdH TB49PdC TB49PdH TW28Pd TW35Pd TW49Pd

4200

L-7021

Grade 11 Grade7 Grade I1 Grade7 Grade I 1 Grade7 Grade 11 Grade7 Gr& m-Pd 7B GradeF-I1 Grade F-7 Grade7 Grade7 Gr%de7 -7 ERTX.2Pd

Smls Pip CD Smls Pip HE Weld Pip Weld Pip CD Smls Pip CD Smls Pip HE Weld Pip Weld Pip CD Smls Pip CD Smls Pip HE Weld Pip Weld Pip CD Smls Pip CD Weld Pip Weld Pip CD

Weld Pip Weld Pip CD Smls Pip CD Weld Pip Weld Pip CD Rod Bar CD Rod Bar HW Bar Rod CD Bar Rod HW Bar Rod CD BarRodHW Wir Wir Wir

Smls Pip CD

Sh Plt Strp Bar Wir Ext Ann

ShPltStrpAnn Sh Strp Plt Ann Smls Weld Pip Wld Smls Pip Ann Smls Weld Tub Ann Smls Weld Tub Ann Bar B11 Ann BarBil Ann Cast FrgAnn Erg Ann Nut Met Nut Blt Scnv Std Met Blt Scnv Std Weld Fill Met

0.07

0.08

0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0. I 0.1

0.1 max 0.1 max 0.1 max 0.1 max 0.05

0.2max 0.015max 0.2max 0.015max 0.2max 0.015 max 0 . 2 ~ 0.015max 0.25max 0.015 max 0.25max 0.015max 0.25max 0.015max 0.25max 0.015max 0.3max 0.015max 0.3max 0.015max 0.3max 0.015max 0.3max 0.015max 0.2max 0.015max 0.2max 0.015max 0.2max 0.015max 0.25max 0.015max 0.25max 0.015max 0.25max 0.015max 0.3max 0.015max 0.3- 0.015max 0.3max 0.015max 0.2max 0.015max 0.2max 0.015max 0.25max 0.015max 0.25max 0.015max 0 . 3 ~ 0.015max 0 . 3 1 ~ 0.015max 0.2max 0.015max 0.25max 0.015max 0.3 max

0.18

0.25

0.2 0.3 0.2 0.3 0.2 0.3 0.2 0.3 0.2 0.2 0.3

0.3 max 0.3 max 0.3 max 0.3 max

0.25

0.015 max

0.0 I

0.0125

0.015 0.0 15 0.015 0.0 15 0.015 0.015

0,0125-0.01 0.0 125 0.015 0.0 15 0.0 15

0.0125 max 0.0125 max 0.0125 max 0.0125 max 0.008

0.05 max 0.05 max 0.05 max 0.05 max 0.05 max 0.05 max 0.05 max 0.05 max 0.07 max 0.07 max 0.07 max 0.07 max 0.05 max 0.05 max 0.05 max 0.05 max 0.05 max 0.05 max 0.07 max 0.07 max 0.07 max 0.05 max 0.05 max 0.05 max 0.05 max 0.07 max 0.07 max 0.05 max 0.05 max 0.07 max

0.04

0.05

0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.05 0.03 0.03

0.05 max 0.0s max 0.05 max 0.05 max 0.02

0.1Smax 0.12-0.25 0.ISmax 0.12-0.25 0 . 1 5 m 0.12-0.25 0.15max 0.12-0.25 0 . 2 m 0.12-0.25 0.2 m&x 0.124.25 0.2 max 0.12-0.25 0.2 max 0.12-0.25 0.3 max 0.12-0.25 0.3max 0.12-0.25 0.3 max 0.12-0.25 0.3max 0.12-0.25 0.15max 0.12-0.25 0.15max 0.12-0.25 0.1Smax 0.12-0.25 0.2 max 0.12-0.25 0.2 max 0.12-0.25 0.2max 0.12-0.25 0.3 IIUX 0.12-0.25 0.3 max 0.12-0.25 0.3max 0.12-0.25 0.15 ITW 0.12-0.25 0.1Smax 0.12-0.25 0.2 max 0.12-0.25 0.2 max 0.12-0.25 0.3 max 0.12-0.25 0.3max 0.12-0.25 0.15max 0.12-0.25 0.2 max 0.12-0.25

0.25 max 0.12-0.25

0.12 0.15-0.3

0.25 0.12-0.25

0.18 0.12-0.25 0.25 0.12-0.25 0.18 0.12-0.25 0.25 0.12-0.25 0.18 0.12-0.25 0.25 0.12-0.25 0.18 0.12-0.25 0.25 0.12-0.25 0.4 0.12 0.18 0.12-0.25 0.25 0.12-0.25

0.25m 0.12-0.25 0.25 max 0.12-0.25 0.25 max 0.12-0.25 0.25 max 0.12-0.25

0.15 0.15-0.25

balm balm balm balm balm baln baln baln balm balm balm balm

balm

balm balm balm balm

balm balm balm balm balm balm balm balm balm balm

baln

baln

baln

0.1 0.3 baln

balm

0.4 balm 0.4 balm 0.4 balm 0.4 balm 0.4 balm 0.4 balm 0.4 baln 0.4 balm 0.4 balm 0.4 baln

baln baln balm

0.4 balm balm

balm

TI.O.2Pd aradea 7 and 11 commltlons: Producer smcmcations

S w c k r i o n Designation Description C Fe H N 0 Pd si OT other

F M Ugine W35-02 Sh Plt Bar Frg Ann 0.08 0.2 0.015 0.05 0.2 0.2

Germany D e u t r k T Contimet Pd 02/30 Mull Forms Ann 0.06 0.15 0.013 0.05 0.12 0.15-0.25 Deuwk T Contimet Pd 02/35 Mull Forms Ann 0.06 0.2 0.013 0.05 0.18 0.15-0.25 h W k T Contimet Pd 02/35 D Mull Forms Ann 0.06 0.25 0.013 0.05 0.25 0.15-0.25

DeuWheT RTIS(Pd) 0.08 0.25 0.013 0.06 0.2 0.15-0.25 0.1 0.3 0.013 0.06 0.25 0.154.25

DeuwheT RT 12(Pd) Sh Strp Bar Frg 0.08 0.2 0.013 0.05 0.1 0.15-0.25

D e u t r h e T RT 18(Pd) Frg

balm

baln balm balm bal Ti' balm baln

(continued)


W.2W grades 7 end 11 cornposltiona: Producer rpec#catlonr (continued)

SDectAestbn Desiemtbn Desetiptbn C Fe B N 0 Pd si OT other

Japan Kobe Kobe Kobe Kok Kobe Kobe SUmiIomO Sumitana s u m i m Toho Toho Toho Toho UK Imp. Metal Imp. Mual USA Crucible OREMET OREMET Rhfl TIMET TIMET TIMET TMCA TMCA

KS4OPdA KS4OPdB KSSOPdA KS5OPdB KS70PdA KS70PdB S T 4 P ST-SOP sT-6oP ISPAT 1SPBT 2OPAT 2OPBT

IMI 260 IMI 262

A40 W n-I1 TI-17 ~~10.25bw Ti-0.2W TKMETAL 35A Pd ‘I?METAL 5OA Pd n . 7 n-11

Mull Fams Ann Mult Forms Ann Mult Forms Ann Mull Forms Ann Mu11 F a n s Ann Mull Forms Ann

Sh Mult Forms

Mull Fams Ann

0.02 0.03 0.02 0.03

0.05 0.05 0.05 0.05 0.05 0.05

0.05 0.B 0.09 0.08

0.0 I 0.03 0.1 0.01 0.03 0. I 0.0 1 0.03 0.15 0.0 1 0.03 0.15 0.01 0.05 0.3 0.01 0.05 0.3

0.m 0.01 0.1 0.005 0.015 0.15 0.005 0.01 0.1 0.005 0.015 0.15

0.08 0.3 0.015 0.03 0.2

0.12-0.2 0.17-0.25 0.12-0.2 0.17-0.25 0.12-0.2 0.17-0.25

0.15 ndn 0.15 min 02 min 0.2 min

0. IS 0.15

0.2 baln

Ti-0.3Mo-0.8Ni (ASTM grade 12), introduced in 1974 for corrosion-resistant applications, is considerably superior to unalloyed titanium in several respects. It exhibits better resistance to crevice corrosion in hot brines (similar to that ofTi-Pd but at much lower cost) and is morc resistant than ~ ~ l l o y e d Ti (but not Ti-0.2Pd) to corrosion by acids. It also offers significantly greater strength than unalloyed grades for use in high temperature, high pressure applications. This often permits the use of thinner wall sections in pressure vessels and piping, that often trans- lates into cost advantages. Ti-0.3Mo-0.8Ni is less expensive than Ti- 0.2Pd grades but does not offer the same crevice corrosion resistance at low pH (4 pH). lnnear-neutral brines, crevice corrosion is similar to Ti- 0.2Pd.

Chemistry CP Grade 12 has allowable ninogen, carbon, hydrogen, iron, and

oxygen levels comparable to Grade 2 and Grade 7 except for a lower carbon content (0.08 wt% vs 0.10 wt% ma). The titanium content in Grade 12 is lowered through the addition of two beta stabilizers, molybdenum and nickel.

Hydrogen content as low as 30 to 40 ppmcan induce hydrogen embrittlement in commercially pure titanium (see the section “Hydrogen Damage” in this datasheet).

Product Forms and Condition Grade 12 can be readily forged and can be cold worked on equip-

ment used for stainless steels. It is available in all wrought forms and can be cast, welded, and machined.

Ti-0.3Mo-0.8Ni products typically have an annealed alpha structure. The tensile and yield strengths of Ti-0.3MM.8Ni exceed those of either the Grade 2 alloy or the Grade 7 alloy. Compared to palladium- containing grades (ASTM Grade 1 I), Grade 12 has double the tensile and yield strengths of Grade 11.

Applications Grade 12 is used in applications requiring m o w strength and en-

hanced corrosion resistance, such as equipment for chemical, marine, and other industries. Recommended environments for ASTM Grade 12 include seawater, brines, moist chlorine above 120 “C (250 OF), hot process streams containing chlorides where crevices may be pres-en4 oxidizing acids, dilute reducing acids, organic acids, and combinations of these with hot, brackish, or saline cooling waters. This material is used for equipment such as heat exchangers, pressure vessels, chlorine cells, salt evaporators, piping, pollution-control equipment, and other fabrica- tions.

Commercially Pure and Modif ied Titenlum / 215

g 350- g 300-

‘I 200-

6 250-

E

I

Tenslie strength, ksl 50 80 70 80 9 0 1 0 0

5501 “ “ “ ‘ “ “ 1 I All specimens unnotched I

0 0 40

250 300 400 500 800 700

Tensile strength, MPa

CPTi: Fatiguestrength at lo7 cycles. Source: Metals Handbook, Vol 1, Pmper- ties and Selection, 8th ed., American Society for Metals, 1961

ASTM grade 4: RT W i n g and axial fatigue

400 ““I \ c Air

R= 0.1 20 Hz I Unnotched - Endurance limit I UTS =

0.7 at 20 and 150 O C Ly

1 o4 1 o5 1 08 1 o7 Cycles to failure

Low-iron grade 2 Ti: Fatigue a t 150 OC. Commercially pure low-iron grade 2 titanium plates containing 0.03% iron or less were double vacuum melted by the consumable electrode arc melting process. The ingots were forged to slabs and rolled to 44.4 or 50.8 mm (1.7 or 2 in.) thick plate product. The plate product was annealed at 730 “C (1345 OF) for 30 min and air cooled. Source: PA. Russo and J.D. Scht)be.l, “Mechanical Roperties of Commercially Pure ‘Ktanium Contain- ing Low Iron,”presentation at ACHEMA 82,1982

Fatigue strength at cyck S t l W lV loC 107

Product fonn Test method stm ratio (R) eonsentretion MPa bi m hi M W kd Bar Rotating beam -1 Smooth, K = 1 517 75 469 68 427 62

Notched, K = 2.7 289 42 262 38 248 36 Sheet Direct smss 0.6 Smoah, K = 1 ... .,. ... ... 538 I 8

Annealed Ti-70 sheet and bax Source: A e m p m Structural Metals Handbook,Volrl,Code 3701, Battelle,lgsS

ASTM grade 3: Reverse bending fatigue

Fotinuestrengthst cycler Temperature stm 106 107

oc O F concentration Mps kd M h kd -191 -312 smooth, K[ = 1 .., ... 689 100

Notched, Kt = 2.7 ... .,. 317 46

Notched, Kt 2.7 151 22 241 35 315 600 smooth, K[ = 1 ... ... 144 21

RT RT S W t h , Kt= 1 289 42 282 41

Annealed Ti-55 bar R = -1. Source:Aerospam Structwal Metals Handbook,Vol4, Code 3701, Battelle,1963


0 . . . . ....I . . . , . ..., . . . . . ,,.I . . . . ....I . . . .

Number of stress cycles

E ii 20

L e -40°C ( - 4 O O F ) 1

1 o4 1 05 1 08 1 o7 1 o0 Number of stress cycle8

ASTM grade 3 Ti: RT rotating beam fatigue strength. Source: Metoh Ha/id- book, Vol3, Pmperties and Selection of Srainless Sfeels. Tool Mnterials ond Spe- cia/ P u p s e Mefais, 9th ed., American Society for Metals, 1980, p 376

ASTM grade 4 Ti: Rotating-beam fatigue shngth. Dara are for urmotched, polished specimens machined from annealed bar stock. Source: Metals Hand- book, Vol3,9th ed.. American Scciety for Metals, 1980, p 378

Commercially pure titanium, like lowcarbon steel, is considered ductile and tough. Because of the low strength and high toughness of commercially pure titanium, planestrain fracture toughness tests we not meaningful unless specimen thickness is greater than about 150 mm (6 in.). This type of test is not practical for routine testing of commercidly pure product. Unlike lowcarbon steel, titanium does not exhibit a good

correlation between absorbed impact energy and other more technically rigorous toughness tests such asdynamic tear energy and fracture toughness. Also titanium, unlike steel, does not exhibit a ducdlelbrittle transition temperature. However, the notched impact test does allow comparison within a given material type and can be used as a quality conb-01 tool.

CPtl: Fracture toughness in air and 3.5% NaCl solution at 25 'C

Pnrile yield Thickness Heat strength KO bar or Kw

Alloy mm in. tmtment(a) MPa Lsl m . l m win, M h d m blh. Ti, grade 2 ,,, ... aA, AC a . . ... 66 MI 66 60 Ti, grade 2 (0.06% 02) 19 0.75 aA, AC ... ,,, 58 53 57 52 1, grade 3 (0.ozOsb 02) 19 0.75 aA,AC ,.. I , , 79 72 14 68 Ti, grade4 (0.40% 02) 19 0.75 U , A C ,,. . . a 99 90 58 53 n, grade4 13 0.50 aA, AC 57 2 83 135 I23 36 33

aA, WQ 586 85 140 128 37 34 STA 565 a2 124 I I3 43 39 M . W Q 524 76 115 I05 71 70 PSTA 530 n 105 96 52 48

(a) &alpha anneal; mbeta anneal; PSTA, beta solution treated and annealed. S o w : R. Schutz, Stres.a.Corrosion Cmcking o/'Z'!tanicun Al&ye, in Ehs+Conwion Cracking: Materials Performance and Evaluation, ASM IntemationalJ992

CP TI: C h a w V.notch Impact toughness

Abaorbed eoem at 20 OC (68 AUoy J R . Ib Ti-3AI-2SV 48 35

48 3s 48 35 54 40

Gra& I 302 223 309 228 305 225 312 230

Grade 2 1 I4 a4 148 109 I67 I23 17 I 126

Grade3 30 22 39 29 43 32 66 49

(a) hngitudinal test direction. Sow: Induatriol Applications of 'IUanium and Zirconium: Third Confirence,R.T. Webster and C.S. Young, Ed., STP 830, ASTM,1084

TYS (0.2%). ksi

200 3C4 400 500 600 700 800 900 lo& TYS (0.2%), MPa

CPTI: Charpy V-notch impact toughness vs yield strength. Source: Induswial Applications of Rtanium and Zirconium: Third Cor,fennce, R.T. Webster and C.S. Young, Ed.. S' lT 830. ASTM. 1984

Commerchlly Pure and MadHled Manlum / 217

TemPerature. OF

-200 -100 0 100 200 300 400 Temperature, OC

CP 'N: Charpy V-notch impact totlghneslr va tempapftva Source: Metals Handbook, Vol3,W ed, American Society for Metals, 1980, p 375

Fracture Mechanism Maps

0 0.2 0.4 0.6 0.8 Homologous temperature (77TJ

1

218 I lltanium Alloy Fatigue Data

Common Name: Tubing Alloy, ASTM Grade 9 UNS Number: R56320

'If3Al2.5V, which is intermediate in strength between unalloyed titanium and'K6A14V, has excellent cold formability required for production of seamless tubing, strip and foil, Like Ti6A14V, 3Ti3Al2.W has a high strengthtoweight ratio and is lighter than stainless steel. Ti3A12.W has 20 to 50% higher strength than unalloyed titanium at both mom and elevated temperatures. It has comparable weldability, and is much more amenable to cold working than Ti6A14V (which does not have good cold forming properties).

Chemistry end Density With 3 W% aluminumas an alpha stabilizer4and 2.5 wt% vanadium

as a beta stabilizer, Ti3A12.W is sometimes referred to as "half 64." High impurity levels my raise yield strength above maximum permitted values or decrease elongation or reduction in area below minimum values,

Density. 4.48 g/cm3 (0. I62 I b h 3 )

Product Forms 2V3A12SV is available as foil, seamless tubing, pipe, forgings, and

rolled products. Ti3A12.5V was developed for tubing and foil applications. Seamless tubing made of 'I"13Al2.5V is readily cold formed on the same type of conventional tubebending equipment used for forming stainless steel. Cold worked and stress relieved tubing generally is not bent to radii less than 3 times the outer diameter in production shops, although radially textured tubing can be bent to 1.5. Relatively thinwall

TIOAC2.SV Speclfimtlonr and comwrklonr

tubing should be bent using tubing fillers or other inside diameter con- straints. V3A12.5V tubing is readily welded by smdardgastungsten arc welding with inertgas shielding and by use of automatic welding tools with built in inert gas purge chambers.

Product Condition/Microstructure Ti3A12.5V is a nearalpha alphabeta alloy that is generally used in the

coldworked and stressrelieved condition. Ti3AI2.W can be heat treated to high strength, but it has vety limited hardenability.

Applications Ti3Al2.5V seamless tubing was Originally developed for aircraft hy-

draulic and fuel systems and has a proven performance record in hightechnology military aircraft, spacecraft, and commercial aimaft. The Lockheed C5A was the f b t military production program in which Ti3A12.5V tubing was employed. This tubing was also selected for the hydraulic system of the Concorde Supersonic Transport. Its fmt application in subsonic commercial aircraft was the Boeing 767. Since then, Ti3A12.5V tubing has been chosen for most of the other commercial transports, commuter aircraft, and spacecraft. This alloy also can be readily rolled in ship and foil, the latter of which is used as the honeycomb layer between face sheets of Ti6A14V sheet in sandwich smc- turns.

'Il3Al2.W is also employed, mostly in tubular fonn, in various nonaerospace applications such as sports equipment (golfclub shah,

COillGdtblh wtk SpcclRcrtion D e s i i t i o n Dwcriptbn Al C Fe H N 0 V OT other UNS R56320 2.5-3.5 0.05 0.25 0.013 0.02 0.12 2-3 wn UNS M632 1 Weld Fill Wu 2 . 5 4 5 0.04 0.25 0.m 0.012 0.1 2-3 baln ChiM

Ti-3AI-2.5V 2.5-3.5 0 . 0 8 ~ ~ o . 3 ~ aoisma~ 0.05nuv: 0 . 1 ~ ~ 2-3 Si0.15max; balm

Europe AECMATi-P69 prEMlZ0 TubCWSR 2.5-3.5 0.0511~ 0 . 3 m a ~ 0.0151~~ 0.02m 0 . 1 2 ~ 2.5.3.5 0 . 4 ~ YO.005ma~;

OEO.1 max; balm

OOST AK2 3 0.25-0.35 2.5 balm GOST IMP-1 Powd 3 0.3 0.01 0.03 0.16 2 Si 0.6: bal 'f?

Russia

USA A M S 4943D AMS4944D

A M S 4944D A M S 4945

ASTM B 337 ASTM B 338 A S I U B 348 ASTM B 381 ASTM 8265.79 AWSA5.16.70 AWS AS, 16-70 MILT-9046J MILT-9047G

Grade 9 orade9 -9 Grade F a 9

ER'L3A1-2.5V- 1 ERTI-3A1-2.5V CodeAB-5 TMAI-2.5V

TubAnn SmlnTub CWSR

Tub CW SR SmlsTub

Smls Weld Pip Ann Smls WeldTubCWSR Bar Bil Ann Frg Ann Sh Strp Plt Weld Fill Met Weld Fill Mel Sh SbpPlt AM Bar Bil Ann

2.5-3.5 0.05 0.3 2.5-3.5 0.05 m 8 ~ 0 .3ma~

25-3.5 0.05 0.3 2.5-3.5 0.05ms~ 0 . 3 m a ~

2.5-3.5 0.05 0.29 2.5-35 0.1 0.25 2.5-35 0.05 0.25 2.5-3.5 0.05 0.25 2.5-3.5 0.1 ma^ 0 . 2 5 1 ~ ~ 2.5-3.5 0.04 0.25 2.5-35 0.05 0.25 2.5-3.5 0.05 0.3 2.5-3.5 0.05 0.3

0.015 0.015 max

0.015 0.0ISmax

0.013 0.013 0.0125 0.0 I5

0.015 max 0.005 0.008 0.015 0.0 I5

0.02 0.02 Tw(

0.02 0.02 max

0.02 0.02 0.02 0.02

0.02 max 0.01 2 0.02 0.02 0.02

0.12 0.12max

0.12 0.12max

0.12 0.12 0.12 0.12

0.15max 0.1 0.12 0.12 0.12

2-3 0.4 2-3 0 . 4 ~

2-3 0.4 2-3 0 . 4 ~

2-3 0.4 2-3 0.4 2-3 0.4 2-3 0.4 2-3 2-3 2 3 2.3 0.4 2.3 0.4

YOxW15;bdTi Y 0.005 max;

0EO.I ms*; balm Y 0.005; bal Ti Y 0.m~ m u ;

0EO.l max: balm bal Ti baln

balm balm bal Ti balTl bd Ti Y 0.005: bal ll

baln

Tl-3AI-2.5V I219

tennis racquets, and bicycle frames), medical and dental implants, and expensive ballpointpen casings. In addition to its high strength-to- weight ratio, Ti3A12.W is being used in such applications because of its excellent torsion resistance (golfclub shafts and tennis racquets) and corrosion resistance (medical and dental products). Golfclub shafts of Ti3A12.5V have been heat treated to tensile strengths of approximately 1140 MPa (165 ksi). Other sports products for which Ti3A12SV tubing is being investigated include ski poles, fishing poles, and tent stakes.

Use Limitations. The rotary flexure fatigue life of pressurized Ti3A12SV tubing is influenced by its crystallographic texture by residual stresses produced in straightening operations, surface roughness, and ovality. Flattening during bending operations reduces the impulse

fatigue life of tubing as a result of the superposition of three additive stresses: residual stresses due to flattening, membrane stresses following pressurization, and bending stresses in the flattened tube wall. Overpres- surization of tubing (autofrettage) can decrease flattening, thus increasing the impulse fatigue life. Use of improper support assemblies may cause end fitting displacement with attendant installation stresses on the final system, outweighing the beneficial effect of overpressurization.

The reliability of tubing is adversely affected by cracking in service resulting From internal and surface irregularities. Production defects may be inclusions, separations in the tubing wall, or fissures at the inner and outer surfaces. Surface damage usually takes the form of chating or denting.

450

400 . I , ” Transverse - _ -

0 I, I

& I t n 350

2300 1

u) t f 250 Q 200

150

100 1 o4 1 o5 108 1 o7 108

Cycles

Ti-3AI-2.W Smooth and notched bending fatigue. Specimens were annealed 1 .O mm (0.040 in.) sheet.

GTA weld metal

/ p anneaied piate

100l . .- . . ...... . ....... . ......I . d m lo2 103 104 105 ioe 10’ lo8

Cycles to failure

Ti-3AI-2.5V: Fatigue of plate and GTA weld metal. Strain-controlled low-cycle and loadcontrolled highcycle fatigue tests were performed on p annealed, sub-P annealed and welded ‘K-3A1-2.5V extruded plate. The axial low-cycle fatigue hourglass specimens had a minimum diameter of 6.35 mm (0.25 in.) and were tested at 2 cycles/min according to procedures outlined in ASTM E606. Ro- tating cantilever beam high-cycle fatigue specimens had 8 minimum diameter of 4.75 mm (0.187 in.) and were tested at a frequency of 6000 cycledmin.

220 I Tltanlum Alloy F8tlgue Data

I

Ti -34 -W. Beding COHepe mgth sheet. Test materisl WBO 1.0 mm (0.040 in.) shset, amrsaled at 785 OC (1450 OF), 2 h, vacuum cooled; ultimate EeMilestrtar8th(Ll88T)538MPa(78ksi). Source: BridgeportBrassCo.Report 1000R436,M.O. 83025,DSC21,1%2;reporoedinArrarplrceShccrumlMetrJs Hand- book, Codo 3725, Battelle Columbus LnhratOries, 1980, p 28

6.4mm(O.250 In.) OD x 0.7mm(0.028 in.) wall 9.5mm(0.375 In.) OD x O.Rnm(0.02B In.) wall, mill annealed

* @.5mm(0.375 in.) wall OD x 0.7mm (0.W in.) wil, a m i d

TMAI-2.W / 221

Impact Toughness

TI-JAt-2,SV Charpy V-notch Impact strength of extruded plate and WldS As-extruded a - p and a heat treated materials exhibit excellent impact toughness, about twice that of the p annealed plate.

As exhlded B atpannealed(n a + p annealed(II) aanneakd Weld metal

I01 J(l4A-lbf) 44 J (32 A . Ibf) 82 J(6Oft Ibf) 87 J(64 A Iw) 86J(63ft*Ibf) 82 J(60A 8 Ibf)

Note: TL orientation; test temperature, 0 "C (32 9). Sourre: I. Caplan, 1PU- 2.W for %water Piping Applications," in Indu&rial Appticrrtiona ofnkLnium and Zhnium: Fourth Wume, ASTM STP 917, C. Y w and J. Durham, Ed., MTM, Philadelphia, ISM, p 45

Ti-3AI-2,SV Charpy V-notch impact strength of 25 mm (1 In.) extruded plate

Test 3Omin,AC tf?YnRefature An extruded 30min,AC 30 mln,AC I m t n , W Q

oc O F J h*lbf J R . l # J R.IM J R ' Ibf J h.1W 93 xwl .., ... 48 36 118 87 123 91 116 86

Kr 107 I9 46 34 86 64 92 68 101 15 0 32 100 74 43 32 81 60 81 60 86 64

4 2 -80 ... ,.. 38 28 69 51 61 45 69 51

Source: Aempxe dmdural Metala Handbook, Code 8725, Battelle calumbus Laboratmies,l9Bo, p 20

Seawater Stress Corrosion. Notched, dead-weight loaded, cantila ver beam specimens measuring 25 rnm (1 in.) by 50 mm (2 in.) by 330 mm (13 in.) were used to evaluate the seawater stress-cormsion cracking performance of heat mated and welded plates. The specimens were step-loaded in Seawater to a given stress intensity and held until failure occurred, or for a maximum of lo00 h. None of the materials displayed any stress-corrosion cracking susceptibility based on fractographic ex- amination of failed specimens. However, the p and sub-p annealed ma-

TMAI-2.5V Sustalned ked cracking of heat treated plate In seawater

Aept tmtmont/ Thmho&O d i n M P d m bidin. B annealed(a) I5 68 SubB annealed 88 80

N o h Teet duration lo00 h. (a)& in air = 81 M p a G ( 7 4 krri&i). Source: I. Caplan, "i-3Al-2.5VforSeawater PipingApplications,* in I n d ~ ~ A p p l ~ t b n a of manium and Zirconium: Fawth Wume, C. Young and J. Durham, EI,ABTM 9TP 017,ASIM, Wadelphla, 1986, p 43

terial did exhibit timedependent sustained load failures. The sustained load cracking threshold stress-intensity value in seawater (KBLC) was defined as the average of the minimum time-dependent failure and the maximum mnout for a given material condition. The weld metal did not exhibit my time-dependent failure up to a maximum stress intensity of 123 M P a G ( l 1 2 k s i K ) .

T19Ab2.5V: Fmcturetoughnesrolextrurlonr In several haattreated condltlonr compared to we# metal

Frreturt brmphw Ur) 'Ru

Condition td/rna jh.ib/in? moduka(a) AS-eXrmded 40 230 I

I0 400 10 93 530 24

B- a t Bannealed (neat B transus) a + pannealed (nearatranrus) 123 700 26 aaMeelcd 100 570 31 Weld metal 151 8M) 27

Note: Chemical cmnpositionofexbuaions: 2.71% A, 0.011% C, 0.006% Cu,O.191% Fe, 0.0014% H, 0.005% Mn, 0.013% N, 0.099% 0,0.015% Bi, end 2.56% Y Weld metal eomporitiom 0.0331 H, 0.009% N, and 0,0969b 0. haaure toughneM wee determined according to AST'M EB13 using oornputer-hbmtive d o d i n g cam- pliance proaedurea (a) Nondimeneional. Source: I. Caplan, "N-SAl-ZtN for Seawater Piping Applications,. in Indwtrial Applicatiam of l h n i u r n and Z h . nium:FouourlhVohme.C.Yo~andJ.Durham.Ed..ASIMSTP917.ASTM.Pbila. delphia, 1988, p 43

Ebaeatbn Uttiaode mile It& Pollkykdd cmdh lnSOmm

Conditbn B&Ih m kli MPI hi (z I&). %

137 118 9 Cold worked mu

Full W(4 Half W a ) 126 98 12

Cdd wc&d plus sms nliewd rnkd@) 909 132 792 115 19 M i 861 125 723 105 16

A& 'Islpicsl@) 648 94 579 84 29

(a) Vdum v r t e d in M n k u n Allcp Handbook, MCIC.HB.IM,lQ72. (b) Tgpieal valwe are an average fnua C.E. Formy, Jr.,and JH. Schemel, ~SAdBWSeurnleee w h l g i n o a r i n g Ouida, 2nd ed., Wvik spselal Metale, 1W. (c) 14% mlnimutn for6.36 and Q.6 mm (0.M md 0376 in.)OD eirse

1034 150 8% I 3 0 7-11

Mlaimnm 620 90 517 75 Is(@

635 mm (azs h) OD Ti-3-25 Ti64

Ti-3-2.5@) n-w) I3 mm @Sin.) OD Ti-3-2.5 Ti-6-4 T i 6 4 Ti4-2.5@) Ti-WC) 19 mm (0.75 la) OD -3-2.5 TI-6.4 Ti-3-2.5 TiWd 25 mm (1h)OD Ti-3-2.2 Ti-6-4 Ti64 Ti-3-2.5(b) n-6-W

34 34 34 20 20

34 34 34 20 20

34 34 20 20

34 34 34 20 20

5 5 5 3 3

5 5 5 3 3

S 5 3 3

5 5 5 3 3

0.55 0.38 0.40 OAO 0.40

1.09 0.66 0.84 0.66 055

1.65 a99 a99 0.84

2.2 1.29 1.61 1.29 1.09

0,022 0.015 0.016 0.016 0.016

0.043 0.026 0.033 0.026 0.022

0.W 0.039 0.039 o m 3

0.088 0.051 0.066 0.05 1 0.043

23,900 19,071 20, 417 17,014 20, 411

23, 317 16.406 21,094 13,672 13, n8 23,511 la, 406 13,672 13, ns 23,900 16,076 21, 094 13,397 13,452

... ... ... ... ...

..,

... ... ... ...

. < I

o.Om 0.0213 0.0226 0.0229 0.0226

0.1200 0.0743 0.0930 OM153 0.0634

0.2719 a m a i m a i m

0.4901 0.2919 0.3718 0.2956 0.2482

... 30.04 26.14

1.31 ...

... 38.08 2250

15.6 ... ..,

38.47

15.7 1 ...

... 4a44 24.14

16.04 ...

Ti-5AI-2.5Sn Common Name: Tk5-21~ md m-5-2142 ELI UNS Numberrr: R54520/R54521

Developed by Battelle for RemCru (later calledCrucible Steel) as an intermediate-strength, weldable alloy, Ti-5A1-2.5Sn was first manufac- tured in 1950. Its primary use was in applications requiring moderate strength and excellent weldability. It was om of the first alloys to be de- veto@ commercially and is one of the few original alloys still in commercial use. Although it is still available from all producm, it is being replaced by Ti-6AI-4V in many applications.

Chemistry and Density As interstitial element content increases, both yield and tensile

strengths increase and frecture toughness decreases. The extra low inter-

stitial (EL0 grade of Ti-5A1-2.5Sn (UNS R54521) is especially well suited for service at cryogenic temperatures and exhibits an excellent combination of strength and toughms at -250 "C (-420 OF).

Density. 4.48 g / c d (0.162 1Winq3)

Product Forms Ti-5AI-2.5Sn is available as bar, plate, sheet, strip, wire, forgings,

and extrusions. The ELI grade is quite difficult to hot work into some product forms, particularly when converting from ignot to billet because of shear cracking, often referred to as strain-induced porosity. Ti-SAl- 2.5Sn can be cast, machined and welded.

224 I Tltanlum Alloy Fatigue Data

Product Conditlonhficros tructure Ti-SA1-2.5Sn is a medium-strength, all-alpha titanium alloy. It has

very high fracture toughness at both m m temperature and elevated temperatures and is used only in the annealed condition.

ricability, oxidation resistance, and intermediate strength at service temperatures up to 480 O C (900 OF).

Ti-5A1-2.5Sn ELI is employed for liquid hydrogen tankage and high-pressure vessels at temperatures below -195 O C (-320 OF), structural members for aircraft, and gas turbine parts. It is used in applications requiring ductility and toughness greater than those of the standard grade, although at some sacrifice in strength, par!icularly in hardware for m i c e at cryogenic t e m p m e s .

Precautions in Use. The elevated temperature stress-codon resistance of this alloy in the presence of solid salt is lower than those of other commonly used titanium alloys. Use of TI-SA1-2.5Sn (like all titanium alloys) in contact with liquid oxygen, or in contact with gaseous oxygen at pressures above approximately 345 kPa (50 psi), constitutes severe fire and explosion hazard.

Applications 'K-5A1-2.5Sn is used for gas turbine engine castings and rings,

rocket motor casings, aircraft forgings and extrusions, aerospace sbuc- tural members in hot spots (near engines and leading edges of wings), ordnance equipment, chemical-processing equipment requiring elevated-temperature strength superior to that of unalloyed titanium and excellent weldability, and other applications demanding good weld fab-

TtbAC2SSn: Smcfflcations and comporitlona

Comwsltbn, wt% (a) S p e f h t i o n Dcsignrtkn Derrlption A1 C Fe €I N 0 Sa OT otkr U N S R54520 4-6 0.1 0.5 0.02 0.05 0.2 2-3 balm UNS w 5 2 I EU 5 2 s UNS R54522 Weld Fill Met 4.7-5.6 0.05 0.4 0.008 0.03 0.12 2-3

balm balm balm UNS

China GB 3620 Germany

R54523 EU Weld All Met 4.7-5.6 0.04 0.25 0.005 0.012 0,l 2- 3

0.3 max 0,015 max 0.05 max 2 3 Si 0. I5 maxi balm TA-7 4-6 0.1 max 0.2 max

WL3.7114 Tl4A1-2.5Sn WL3.7115

4.5-5.5 4-6 44

0.08 0.08 0.08

0.5 0.5 0.5

0.015.0.02 0.05 0.02 0.05 0.02 0.05

0.2 0.2 0.2

2 3 0.4 2-3 2-3

bal Ti bal Ti balm

DIN 17851 DlB 17851 Ruruh, GOST

OOST 19807-74

Sh Strp Plt Rcd Wu Ph Sh Strp Ann

vT5-IKT

Vn-1

4-53

4.6

OM

0.1

0.2

0.3

0.008 0.04

0.015 0.05

0.12

0.15

2-3

2-3 0.3

Zr0.2; h4n 0.1; Si O.l;balTl

D0.3; Si 0, IS; bal Ti

Sh Plt Snp Rod Frg Am

spoil UNE38-716 UK BS TA 14 BSTA15 BSTA16 BSTA17 USA AUS4W9D

AMs49101 A M S J924D

AMS 4 ~ 6 ~ A M S 4953D A M S 49663 ASTh4 B 265 ASTMB348 ASTM B 367 ASTh4B381 AWSA5.16-70 AWS AS. 16-70 MIL F-83142.4 MnF-83142A MILF43142A MILT-81556A MILT-81556A MILT41915 MIL T-9046J MIL T-9046J MILT-90470 Mn. T-W47G

L-7101 Sh Sup Plt Bar Frg Ext 4.5.5.5 0.15 0.5 0.02 0.07 0.2 2-3 balm

Sh Bar R8 Fik

4-6 4-6 4-6 4 6

0.08 max 0.08 ma* 0 . 0 max

0.5 max 03 max 0.5 max 0.5 max

0.0125msx 0.0125 max 0.0125 msx 0.015 max

2-3 2.3 2.3 2.3

MTi baln balm balm

ELI Sh Sup Plt Ann

Sh StrpPlt Ann ELI Bar- Rng Ann

Bar Wir Bil Rng Ann Weld RU Wu RgAnn

Grade6 Sh Strp Ill Ann Grade6 BarBilAnn olade C-6 Cut Grade F-6 FlgAnn ERli-5AI.2.5Sn- 1 EU Weld Fill Met EKMAI-2.5Sn Weld Fill Met -2 FrgAnn

M A - l Ext Bar Shp Ann M A - 2 EU Ext BarShpAnn 'ISlpenCompA CastAnn W A . 1 Sh Strp PI1 Ann -A-2 ELI Sh Strp Plt Ann m-5AI-2.5Sn Bar Bil Ann TI-SAI-2.5Sn ELI ELI Bar Bil Ann

Frgm ELI Frg Ann

comp2 COW 3

4.5.5.75

4.5-5.75 4.7-5.6

4-6 4.5-5.75

4-6 4-6 4-6 4-6 4-6

4.7-5.6 4.7-5.6 4.5-5.75 4.5.5.75 4.5-575 4.5.5.75 4.5.5.75 4.5-5.75 4.5.5.75 4.5.5.75 4.5-5.75 4.5-5.75

0.05

0.08

0.25

0.5

0.0125 0.035

0.02 0.05

0.12

0.2 0.12

0.2 0. I75 0.2 02 0.2 0.2 0.3 0. I 0.12 0.2 0.2 0.12 0.2 0.12 0.2 0.2 0.12 0.2 0.12

2 3 0.3

2-3 0.4 2 3 0.4

2.3 0.4 2-3 0.4 2-3 0.4 2-3 0.4 2-3 0.4 2 3 0.4 2.3 0.4 2-3 2.3 2 3 0.4 2.3 0.4 2-3 0.3 2-3 0.4 2-3 0.3 2-3 0.4 2 3 0.4 2 3 0.3 2 3 0.4 2-3 0.3

Y0.005;0+pe= 0.32; balm Y 0.W5; bal Ti YO.WS;O+k= 0.32: balTi

Y 0.005: w 'II Y0.005:bal'II Y 0.005: bal n balm balm balTi baln balm balm balm ban bal Ti balm baln bal Ti bal Ti balm Y 0.005; balm Y 0.005; balTi

0.05 0.25

0.08 0.5 0.08 0.5 0.08 0.5 0. I 05 0.1 0.5 0. I 0.5 0. I 0.5 0.04 0.25 aos 0.4 0.08 0.5 0.B 0.5 0.05 0.25 0.08 05 0.05 0.25 0.08 0.5 0.08 0.5 0.05 0.25 0.08 0.5 0.05 0.25

0.0125

0.02 0.015 0.02 0.02 0.0125 0.015 0.02 0.005 0.008 0.02 0.02 0,0125 0.02 0.0125 0.02 0.02 0.0125 0.02 0.0125

0.035

0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.012 0.03 0,os 0.05 0.035 0.05 0.035 0.05 0.05 0.035 0.05 0.035

TI-5AI-2.5Sn I225

TlQAI-2.sSn: compositknr

Comptlllithwtck (a) soecmtbn DniEMtioa Dervlptkn Al C k E N 0 sa OT other

PRna Ugine UTASE ShBarAm 45.5.5 0.15 0.5 0.02 0.07 0.2 2-3 baln U g h UTASEL ELIBarAnn 454.75 OM 0.25 0,0125 0.035 0.12 2-3 beln

DeuWhe T Contimet AlSa 52 Sh Sup Plt Bar Frg Pip Ann 43-55 0.08 0.5 0.02 0.05 0.2 2-3 balm DeutscheT CwdrnejAlSn52EU ELIPItBarFrgPlpAnn 93-56 0.06 0.15 0.013 0.05 0.12 2-3 balm Fucb TLs2 Frp 5 2 5 balm Japan Kobe Kobe MMA sumimo TDho USA ORPAET RMI RMI TIMET TMET

KSS-2.5 Am KS5-2.5ELI ELIAnn 5137 SAT-525 525AT

4-6 4.7-5.6

0.5 0.02 0.05 0.2 2-3 baJ 'IT 0.25 0,0125 0.035 0.12 2-3 baJ TI

4-6 0.03 0.5 0.M 0.05 03 2-3 bsln

Tl5-2.5 RMI 5A1-2.5Sn Mult F m Ann 4.6 0.08 0.5 0.01754.02 0.05 0.2 2-3 RMISAl.2.SSnELl ELIMultFmr Ann 4.7-5.7s 0.08 0.25 0.0125-0.015 0.03 0.13 2.3 balm TIMETALS-2.5 Am 4-6 0.1 maX 0.5 max 0.02 max 0.09 max 0 . 2 m 2.3 balm TIMETALS-2.5 ELI Am 4.5-5.75 O X H m 0.251~ 0.0125max 0.035max 0.12max 2-3 baln

(a) Maximum wkta a range is specifiid

Uitlmate tensile strenath. ksl

2.2Fe-2.1Cr-2Mo

0 500 loo0 1500 Ultimate tensile strength, MPa

Ti-SAI-2JL: Fatigue endurance ratio comparison. Source: TML R e p n No. 77, Battelle, 1957

/ -- Hand finished

Gmund

I

I r: I 1"

10' 10' 10' 10' 1 on Lifetime, stms OyCleS

Ti-SA1-2.5Sn: Rotating-beam fatigue strength. Effect of surface finish. Source: Metals Handbook, Properties andSeIectim: Stainless Steels, Tool Mate- rials, and Special-Putpme Materials, Vol3, Rhed., ASM, 1980

226 I Tltanlum Alloy Fatlgue Data

" I \ Ultrasonic maehlned I \ t 4100

20 Electrlcaldlscharge meehlned

0 . . . ....., . . ......I . . ......I . . . 1 o4 10' 1 oe 1 0' lo"

Ufetlme, stress cycles

Ti-SAl-25Sn: Rotating-beam fatigue strength. Effect of surface finish. Source: Metah Handbook, Pmperties and Selection: Stainless Steels, Tool Mate- rials, andSpecial-PurpOse Materials, MI 3 , %h d., ASM, 1980

m BOOC

1 o4 1 0' 10' 1 0' 1 0' UleUm, stress cyclbs

Ti-5Al-2.5Sn: Rotating-beam fatigue strength. Notch fatigue strength for two notches. Source: Metals Handbook Pmpem'es and Seleciion: Stainless Steclr, Tool Mareriais, andSpecia1-Purrrpose Materials, Vol3.9th ed., ASM, 1980

4,O 2.33 1 .s A e 1 0.67 0.43 025 0.1 1 -0.6 4 4 42 R= 0 0.2 0.4 0.6 0.8 1

-120 -100 -80 4 40 4% 0 20 40 80 80 100 120 140 I80 160 Mlnlmum stress, ksi

I

Ti-SAI-2.Sn: Constant life diagram of mill annealed sheet. Source: MLHDBK-S,1972

TMAI-2.5Sn / 227

LowTemperature Fatigue Data

1 O8 10' ld 1 Qe 10' Number of cyctes

Ti-SAI-25Sn ELI: Fatlgue strangtb va tempezature. Sourw: TlIEtanium Prod- uct Literature, K o k Steel

8mcang mod2 Axial

Axial

Axial

Axial

Axial

Flex

sbera nth, R K,

0.01 1 3.5

0.01 1

Q 1

0.01 1

0.01 1 3.5

-I .O 1 3.1

495 72 815 118 760 110 220 32 205 30 160 23 485 70 565 82 42s 62

760 110 985 143 925 134

505 73 675 98 895 130 285 41 295 43 275 40 600 81 595 86 560 81

345 50 550 80 530 n 170 25 185 27 255 37

~

TMAI-2.SSn: Fatigue crack growth ofannrmled sheet at mom temperatun

FstlguecRckemwtb~ m/cycleWakrlch at:

A K = 5 . 5 M p a ~ ( 5 L r s i ~ ) , A K = l l M P n ~ ( l O k s I ~ ) , AK-22Mps&(20ksi~) , AK-SSMPPG lest environment LTspeimenorfeatPtion Dry argon 0.00075 0.00685

Labair 0.0038

Distilled water 0.00635

3.5% NsCl 0.0074

T-Lspecimen orientation

R - 0.67, and 55-SB Bz R = 0.67, and 55-58 Hz R=O.l .andSSH74a)

0.12-0.14

(50 b&). R - 0.1.30 Bz

240 (0.03) (on) (4.77-5.56) (94.7)

(0.1 5 ) (2.13) (11.611.7) (124)

(0.29) 0.97) (235.302) w n (0.25) (3.49) (1 1.8xa) (124)

Dryargw ... Lab air 0.0038

Distilled water 0.009

3.5% Nacl 0.025

(0.49) (5.355.38) (114)

(0.15) (3.08) (1 1 .% 11.9) (141)

(0.36) (3.72) (12.0-12.5) (130)

(0.98) (14.6) (243@) (176)

(a) The higher m e a d values correspond to tests at 30 Hz. (b) 60 Hz. Source: J. Gallagher,Domage lMemnf Design Handbook, MCIGHB-OfR, Battelk, I983

228 I Titanium Alloy FaUgur Data

W C 2 5 S n : Fatlgw cnck growth ma cafnpmd to W A M V Crack growth parameters per the relation da/# = C (dx)"

m f b r M coaatthao Orhtrtka oc O F %ATk YEP n MprJm A p g d

Tl.5A1-25Sa T.S 24, -1% -269 15, -320.42 5.1 x 10-11 32 x 10-12 48 14-30 13-27

Tl-5A1.2.5Sn T-L m, -196, -269 75, -320, -452 4.9x 1 l F J 2.8 x lo-" 4.0 lodo 9.54

C mbated lbrtmlrrrtum

m-h cLD,-i=

momkdbrr Ti-aAJ4VO$ FL u, -1% -269 15, -320 ,452 3.1 x 1Vla 2 2 x lo-* 60 14-30 13-27

T i - W V T-L 24,-1%,-269 75,420,452 1.9 x 1w-13 1.4x 1v14 7 .O im 9- 18 24,-1% 15 -320 3.0x l@ 1.6X l@ 39 204 1&36

amaedbar

R= 0.7

1 10 102 Strw-lnleneity factor range,

AK, Win.

Ti-SAI-2.58n ELI: Crack growth at mom temperotprc S o w : D.B. Mate- jczyk et al,, Fatigue Crack Retardation Following Overloads in Inconel 718. 'II. 5A1-25Sn, and H a p s 188, Advanced Earth-to-Orbit Prqpvlpion Technology 1986,~12NASAConfawcePublicad~2437,1986,p205-219

W A l - ~ m r r me&an&m map Source: KrMmamohnrao et al., Practure Mschanum ' Maps for Titanium and Its Alloy, Acra Mefall., %l 34, 1986, p 1783-1806

0 2 4 6 8 nm, min

TidAI-2.Bn: "hmto-hcture. EBwt of initial stlcos intensity on ttllbto. fractm at ambient temperature. hum: R. wood md R. Pam, 7itMivmAUoys Handbook, MCIC-HB-02, Baacllt Columbua Lahaton '* r9n

Low Temperature Toughness (Standard and ELI)

TlbAC25Sn: Fracture toughness

Hest T&#t Spedmm, ntld

vahbbh) K O F hfPa Jm lrsi hfia, and trpe(C) Mp. bJ &futdatd gmde

tmotmml temparturn Streg I N d h Kw orlentation(b) atmngtMdl

Alr cooled 295 72 71.4 65 cr-m 876 127 n -320 53.8 49 LT-m 1338 194 20 423 51.6 47 LT-B 1482 215 2o 423 505 46 S B I * , ...

Furnaeeooded 295 72 65.9 60 rr-cr 882 128 n -320 57.1 52 r r a 1379 200 20 4 2 3 472 43 LT-B 1517 220 20 4 2 3 52.7 48 LS-B ... ...

Air cooled 295 72 118.7 1We) 703 102 71 -320 111.0 101 LT-CT 1179 17 1 20 4 2 3 91.2 a3 LT-B 1303 189 20 -423 106.6 97 LS-B ... I,.

Fulw2ecooled 295 72 115.4 W e ) LT-CT 682 99 77 -320 82.4 75 I3-m 1179 171 20 423 68.1 62 LT-B 1303 189 20 423 80.2 73 LS-8 ... ...

ELI gRde

(a) Air cooled or fumaca cooled ffam annealirrgternperature. (b) orientetlan notation per ASTM ES9874 (c) Cl', compact tensian rpecimen; B, bend epedmen (d) 0.2% ~ ( e ) I m r s l i d ~ e s v a l u e e ( n o t 1 0 0 9 b ~ e t r a i n ~ d i ~ ) . ~.M~leX~book,v~ls,gthed.,Americsn~fmMs~, w , p w

~

tlbAC2.tiSn: Comparlron of fracture toughness of two tttanlum alloys

876 I 2 7 m 876 127 Bad 876 I 2 7 Bmd 871 126 CT 703 102 CT '103 102 Bend

760 110 CT

779 113 cr 942 136 CT

830 120 CT

830 120 CT

830 120 cr

71.8 ... ...

77.2 1 1 1 ... . I .

. I .

I..

47.4

,..

...

. a .

8 . .

1 1 1 ... I . .

53.4 ... 1..

42 1 111

1..

...

.I(

I # .

38.8

61.0

62.8 62.0 61.1(d)

56.Xd) 57.l(e) 5 1 .oo

48.6 ... ...

38.3 101 ...

4. .

. ( I

, I ,

35.3

55.5

57.2 56.4 55.Wd)

51.8(d) 52.Ne) 46.40

. I . 1 1 1

51.4 46.8 50.2 45.7 .,. I , ,

( I . . , I

89.6 81.5

79.4 72.3 585 53.2

54.475.3 495685

... . I ,

I,, .,, ... .,. ... .,.

I,. ... ... 420 ... ... ... . I ,

. I ,

385

54.1

... ...

.,.

...

.,. ..*

... ... ... 38.2

. I ,

.I,

. , a

.I,

.I,

35.1

49.2

.,. ... ...

a , ,

, I ,

. a .

230 / Titanlum Alloy Fatlgur Data

TI-$AC?.SSn(EU): Fnatuntoughnc#rot13 mm(0.601nn.)thickplate

mectbn hfP4 M hfPdm Win

Is 12M 175 73.0 67.0 1% 179 76.0 69.8 1206 175 67.0 60.8

Ts 1199 174 58.0 52.8 1199 174 51.0 46.4 1199 174 54.5 s1.5

LD 1206 175 a6 55.2 1#)6 175 63 x) m 1206 175 60.0 55.0

TD I199 174 60.6 552 1199 174 64.0 58.4 1199 174 59.5 54.2

At-mx ts 1413 205 56.4 51.4

1413 20s 65.0 59.6 1413 205 59.7 54A

Ts 1441 209 53.0 48.8 1441 209 593 54.0 1441 209 59.5 54.2

LD 1413 205 58.9 53.6 1413 205 59.9 54.6 1413 2a5 51.8 473

TD 1441 209 65.0 60.0 1441 209 69.0 63.6 1441 209 65.0 59.2

ndlewatraacth KO.

At -195 Dc (-3ZO "p)

Nate: B d b u -6.4by 18 m ( 4 , by %h). LO wt%Al, O.Olswt% C,O.lBwt%h, O.OOlwt% H,O.008MMqO.OlOwt%N, 0.088 wt% 0, a d 26wt% 8a Plate mrnMBid by hnaca c d a g h n 816 oC(1Mx1 OF).TheT98pedmeno~tiPnhadanrcLdirectionpuJleltotbe*h t b o n S a a e e : C . C a n n a n p n d J . K a t l i a , c p l r n e S ~ ~ ~ a n d ~ ch.nicpl F%pedim dlw-2.6.8pr ELI d commend ' TFdaniumAuoyratRoom md CryOgmb Temperatures: m & ~ ~ ~ PheMmeM in 7itMirUn Alby#,ABTMm452,AsTM, 1888,p 124

T1QAM.6Sn: Fracture toughnem ol l3 mm (0.1 In) thkk phta

Mraftbn m Ld M W m wia At-l%0C(3#I°F) Ls 1399 m 333 30.2

1399 m 285 26.0 1399 m 24.9 22.7

TS 1466 204 64.1 58.4 1406 2M m.4 45.9

LD 1399 m 44.9 40.9 1399 203 43.6 39.7 1399 203 26.9 245

lD 1406 204 27.8 25.3 1466 1Do 30.1 27.4 1406 a4 24.6 22.4

At-rn.C(423.F) Is 1646 233 21.5 19.6

1646 233 29.4 2bA 1606 233 30.1 27.4

Ts 1634 237 503 53.1

LD 1606 233 527 48.0 1606 233 Ma 31.7 1606 233 213 19.4

'ID 1634 231 24.0 21.9 1634 237 25.6 23.3 1634 237 23.3 21.2

6.4 by 1s m (I/rg % h), c w oompdth 5.1

mJidddrarpth K,

1634 237 30.2 27.5

Noh: Bend bu wt%* 0x128 wL% C, 0.M *%Fa, 0.017~t%H,O.O08~t% Mn,O.Ol6wt%N, md 2.3 wt% 8p Plate waammdedbyiimvEe ~ & o m 8 l S O C ( l b M 3 "Fx &unx C . C a r n r s n . n d J . K a t l i n , C R a o s S k a i n ~ ~ r a d ~ R o p e r h cfM1-2.ShELI a d commerdal ntrniuOr Allon at Boom rrd CrJloSsnie kperatunja," fa Appligtionr Related Phomena iaTbdumTit.nknnASI'M m432,AsTM, l!368,p u4

.... . . ..,/... . - ........................ ~, .....

. - ....................... ~

DJ I I

_ - _ - ...... _. -.r ........ .-.._,

... - ._ .................... A ...... _,,

-250 -225 -200 -175 -150 -125 -100 Testlng temperature, *C

-WO -225 -100 -175 -150 -125 -1bD Testing temperature, OC

rrCiAC2.SSn / 231

TibAc288n 0: Fmchlretoughnua d6.4 mm (02s In.)thkk prrbb

Dbaetba MR kd wia At -195 .C (jaa op) Ls 1 I72 im.5 60.1 62.0

1172 170.5 67.4 61.4 1172 1m.s 69.4 633

Ts 1199 174.5 54.1 493 I199 1745 62a 573 1199 1743 63.7 58.0

Ls 1172 1703 67.0 61.0 I172 1m3 70.9 w.6 1172 im3 7oa 645 1 in 1705 74.6 679

Is 1199 1743 66.9 60.9 1199 1745 72.5 66.0 1199 I743 64.4 58.6 1199 1743 70.3 64.0

~ 4 s 2 ~ ( 4 2 3 ~ ~ Ls 1344 1% 61.9 544

1344 1% 593 54.0 1344 1% 56.7 51.6

PndhJtaartrrPats KW

Ts 1248 181 53.6 a a 1248 181 54.7 Ma 1248 181 45 9 41.8

~ C h m i c e l ~ ~ S.Owt%Al,O.tB3 wt% C, 0.16 wt% Fe, O,oOgwt% H, O.CMMwt% Ilan, 0.010 wt% N,Ox##)wt% 0, a d 2.6 wt% 8n Plate w u -by hmrcb coolingitmn 816 g: (MOO 'Fx Eoum C. Crnnrn and J. Katits % ~ ~ ~ d M r r ) l . n ( a l ~ o f s A l - 2 . s s n E L I a n d C 0 m . lwrdalTitnuium Alloyr at Ronm md cryuge&Ibml#nturer: inAppiimti0nr Rdotrd PhaooiMIli in ntuniumMoya, AlpTM SFPa,AgTM, 1888, p Zar

0 0.6 1 1 .s I

fldAczBsn (EU): Fmture toughnna of26 mm (1 In.) thbk pbts

Dtrertba MPa bd MR4m WlB At -195 .C (jZ0.p) La 1213 176 62.5 56.9

1213 176 57.2 52.1 1213 176 a 9 46.4

Ts 1213 176 5Q5 46.0 1213 176 ss.7 50.7

LD 1213 176 65.4 995 1213 176 673 61.3 1213 176 582 53.0

TD 1213 176 70.5 642 1213 176 81.9 74.6 1213 176 66.3 60.4

At-= .C (-423 OF3 Ls 1399 243 49.4 45.0

1399 203 69.9 63.7 1399 243 62.6 57.0

'1s 1399 243 51.3 6 7 1399 203 60.9 553 1399 203 60.6 23.2 1399 243 61x7 55.3

LD 1399 243 s0.5 46.0 1399 203 61.1 55.6

TD 1399 203 ma 61.0 1 W 203 838 363 1399 293 rns 64.2

PlldbriddmartL K,

NOW Bend bar- Clwdcal mpcdtbm 1.1 arf(k Al, O D 2 6 r 1 8 C, a14 -Fa, 0.008 wt% H, O.WntSbMn, 0.101 wt%O, rrrd 2.4 wt% S n Flab M ~ P ~ b g f b m r e e ~ f t o m 8 1 6 % ( 1 M x I o F ) . ~ C . ~ d J . K . t l l n , Thna BbJn IhctLlm Touglmm md Mechdcd propsrthr dMl-%6&lELI a u d C h m m L s l T i t a n i u m A U o p r a t I b o r n d ~ T e m ~ ~ ~ i P A p p l i - a o f h ~ a o k d phan~mr~r m l w n e, AE~TW mrsa,m, m, p w

Temperature, O F 400 -200 -100 0 1w

I

: ..{ id ....,. -", .,_. -"",& ..,... _-. . ....... ; ......... .............,.... , ~

I I 0 8a 180 240 820

Twnperature, K

Ti-sAI-2Jsn ELI: EhEtlvbtmlghEH at #vnpl tempmtWw9 Auoy tsstcd was ex--low intmitial g d e with typical composition of 4.70 to 5.6Owt% Al, 025 wt% Famax, 0.0125 wt% H m u , 0.035 w% N max, 0.12 wt% Omas ad 2.oto 3.0 wl% Sa sollrce: 'ITmiPm Roduct Litaahm, Kobesteel

232 / Tltanlum Alloy Fatigue Data

Common Name: Tl4242S 71424281 UNS Number: R54620

Ti4AI-2Sn-4Zr-2Mo-0.08Si (Ti-6242s or Ti-6242Si), developed in the late 1960s as an elevated-temperature alloy, has an outstanding combination of tensile strength, creep strength, toughness, and high-tem- p t u r e stability for long-term applications at temperaturesup to425 "C (800 OF). Ti4242S is one of the most creep-resistant titanium alloys and is recommmded for use up to 565 'C (1050 OF). Proper heat treatment is important in allowing the alloy to develop its maximum creep resistance.

Chemistry and Density The 6 percent aluminum addition in the TidAI-2Sn-4Zr-2Mo com-

position is apotent alpha-phase stabilizer, while the 2 percent molybdenum addition represents only a moderate quantity of this potent beta- phase stabilizer. The tin and zirconium additions ate solid-solution strengthening elements that are neutral with respect to phase stabilization. The net effect of this combination of alloying elements is the gen- eration of a weakly beta-stabilized, alpha-beta alloy. Since it is weakly beta stabilized, the alloy is also properly described as a near-alpha, alpha-beta alloy.

The original composition of this alloy containedno silicon, but RMI introduced a nominal 0.08% silicon content which allowed the alloy to mect the creep requirements for its intended jet-engine applications. Be- f m any major commercial applications were developed, all producers had added silicon to the original 3-6242 composition,

Density. 4.54 g/m3 (0.164 Ib/inS3)

Product Forms Available mill forms include billet, bar, plate, sheet, strip, and extru-

sions. Cast Ti-6242S p d u c t s constitute about 7% of cast titanium products. Some forming operations can be carried out at mom temperature, and warm f o d n g (425 to 705 'C, or 800 to 1300 OF) is employed when necessary. Ti4242S has fair weldability. The molten weld metal and ad- jacent heated zones must be shielded from active gases (nitrogen, oxygen, and hydrogen).

Product Condition/Microstructure Ti-6242s is sometimes described as a near-alpha or superalpha al-

loy, but in its normal heat treated condition this alloy has a structure better described as alpha-beta. Proper treatment is needed to develop good creep resistance. Limited hardening of Ti-6242s can be done by solution treating and aging.

Applications Ti-4242s is used primarily for gas turbine components such as com-

pressor blades, disks, and impellers, and also in sheet-metal form for engine afterburner structures and for various "hot" airFrame skin applications, where high strength and toughness, excellent creep resistance, and stress stability at temperatures up to 565 OC (I050 OF) are required.

Ti-6AI-2Sn4Zr-2MoQ.OBi: Speciflcetlans and compositions

Composition, wt% Specification Deslanstbn Descridbn Al Fe H Mo N 0 Sn Zr ciher UNS -20 6 2 2 4 balTi U N S R5462 1 Weld Fill Met 5.5-6.5 0.05 0.015 1.8-2.2 0.15 03 1.8-2.2 3.64.4 CO,W,CrO,25;balTi Germany

WL3.7144 5.56.5 0.25 0.015 1.8-2.2 0.05 0.15 1.8.2.2 3 .644 C0.05:balTi Spaln UNE38-118 UNE38-718 USA AMS49192

AMS49190 AMS 49758 A M S 4975F

AMs4976c

L-7 103 Sh S!q Plt AM 5.5-6.5 0.25 0.015 1.8-2.2 0.05 0.12 1.8-2.2 3.6-4.4 C0.05;0T0.4~balTl L.7 103 Sh Sup PIt HT 5.5.6.5 0.25 0.015 1.8-2.2 0.09 0.12 1.8-2.2 3.64.4 C0.05;OT0.4;balTi

Sh Svp Plt 5.54.50.25ma~ 0 . 0 1 5 ~ 1.8-2.2 0.0511~ 0 . 1 2 1 1 ~ 1.8-2.2 3.6-4.4 CO.O5max;SiO.06-0.1:YO.oO5max;

Sh Sap Plt DA 5.5-6.5 0.25 0.015 1.8-2.2 0.05 0.12 1.8.2.2 3.64.4 C0.05;SiO.l;Y0.005;OT0.3;balTi BarWrRngBilSTA 55-6.5 0.25 0.0125 1.8-2.2 0.05 0.15 1.8-2.2 3.64.4 C0.05;YO.~;OT0.3;SiO.l;balTi BarRngHT 5.5-6.50.111~ 0 . 0 1 2 5 m 1.82.2 0.05m 0.1Smax 1.8-2.2 3.64.4 CO.O5max;SiO.o6~.1;YO.oO5max;

4 STA 55-65 0.25 0.0125 1.8-2.2 0.05 0.15 1.8-2.2 3.6-4.4 CO.OS;Y0.005;OT0.3;SiO.l;baln

0EO.I m; OT0.3 max: bal Ti

OEO.l m; OT 0.3 nrax; bal Ti

USA (m AMS 4976D Fin HT 5.56.50.1max 0.0125max 1.8-2.2 0 . 0 5 1 1 ~ 0 . 1 5 1 1 ~ 1.8-2.2 3.6.4.4 CO.O5max:SiO.06-O.I:YO.W5max: "

OEO.l nw.; OT0.3 n k ; bal Ti .

MILT-81556A CodeAB-4 Exf BarShuAnn 55-63 0.25 0.015 1.6-2.2 0.04 0.15 1.6-2.2 3.6-4.4 CO.O5;YO.D(H;SiO.oM).I;OTO.3;bal Ti

n MILT-81556A CodeAB4 Ext BarShpSTA 5.5-6.5 0.25 0.015 1.82.2 0.04 0.15 1.8-2.2 3.6-4.4 C0.05;SiO.~O.l;Y0.005:OTO.3;bal

MILT41915 TypeJIICompB CastAnn 5.5-6.5 0.35 0.015 152.5 0.05 0.12 1.5-2.5 3 6 4 A CO.O8;OTO.4;bdTi MILT-90461 CodcAB.4 Sh Sap Mi DA 55-63 0.25 0.015 1.8-2.2 0.04 0.15 1.8-2.2 3.M4.4 CO.OS;OT0.3;bdn MILT-W6J W A B 4 ShStrpPltTA 556.5 0,25 0.015 1.8-2.2 0.04 0.15 1.82.2 3.6-4.4 C0.05;OT0.3;balTl MILT-#)I)7G Ti-6AI.2Sn-4Zr-2hio Bar Bil DA 5.5-65 0.25 0.015 1.8-2.2 0.04 0.15 1.8-2.2 3.6.4.4 C0,OS;OT0.3;Y0.ooS;balTi MILT-9047G TI.6AI.2Sn-4ZI.Wo Bar Bil STA 5.5-6.5 0.25 0.015 1-8-2.2 0.04 0.15 1.8-2.2 3.6-4.4 CO.M:Y0.005;OT0.3~b~Ti

TI-GAI-~S~-~Z~-~MO~I.OSSI / 233

0

TMAl-23n42r-2MbQ.0881: Compositions

Compsitbn,wt% s#fi&atba Desimth Dcsrlption A1 Fe B M O N O so Zr 0th

R = [(l - Ay(1 + A))-20 Wbd (14 = 3) r = 0.025 , , , , . , . / , , , ..,., , . , .,.,,, , , ,

hure ugim UT6242 BVRgAnO 5.5-65 1.8.2.2 18 -22 3.6-4.4

De~tsckT cauimCAlSnzIMO6-2-4-2 PllBarRgAnn 5.5-65 0.25 0.015 1.8-2.2 0.05 0.15 18.2.2 3.6-4.C 0.05; M 0.06-0.12: balll DeutrhcT ContimaAlSnZlMo6-2-42 PltBarPrgSTA 55-65 0.25 0.015 1.8-2.2 0.05 0.15 162.2 3.64.4c0.05;si0.(Mo.12;bal~ DeutsckT LT24 A64 FUChS TL62 Frg Japan Kobe Ks6.242 Bar Frg STA 5.5-65 0.25 0.015 1.8-2.2 OM 0.15 1.8-2.2 3.6-4.6aln UCA

5.5-65 0.25 0.015 1.8-2.2 0.W 0.12 162.2 3.64.4CO.05;balTi 6 2 2 4 balTi

OREMET 1-6242 RMI RM16AI.2Sn4Zr.2Mo.00,10Si BmBilPlt Sh 55-65 0.25 0.01-0.0125 1.75-2.25 0.05 0.12 1.75-225 3H.EO.08,SiO.l:balTi

STA

STA TIMET 'ITMETAL 6 2 4 2 Bar Bil Plt Sh 5.5-65 0.25 0,01-0.0125 1.75-2.25 0.05 0.12 1.75-2.25 354.~0.OS,SiO.l; WTi

The structures of ll-6A1-2Sn-4Zr-2Mo alloy are typically equiaxed a in a transformed p matrix, or a fully transformed structure that maxi- mizes creep resistance, The quiaxed a grains found in sheet products tend to be smaller than those found in forgings, as with other alloys, and are present in greater proportion than in forgings. Primary a is typically about 80 to 90% of the structure in sheet products and can be somewhat lower than this in forged products, because the final forging temperature is normally higher than the final rolling temperature used for sheet. As in

other near-a alloys, small amounts of residual j3 phase can be observed metallographically within the transformed p portion of the structure, typically between the acicular a grains of the transformed phase. Breakup of lamellar a into equiaxed a occurs during working (see figure).

Beta W s u & 995 f 15 OC (I825 f 25 OF)

Duplex Annealed Sheet

swl I -ij Unnotehod (K, I 1)

I N W h d (4 3)

10' 10' 1 o8 10' Id cyclestofrachrre

Ti-6242: Fatipe propertieu at 205 Qc Specimens were 1 mm (0,040 ia) sheet duplexannealedat900~((1650~,30min.AC+785 *C(1450°F), 15min,AC. Axial fatigue, tension (sinusoidal). Surface: mill finish. Frequency: 25M3 cycledmin. ' b t temperature, 205 'C (400 "p). Source: A M - T R 4 7 - 4 1 , Apr 1%7,reportedinAerospaceSrructumlMeralr Hand&ok.vOl4,Code 3718,Bai- telle Columbus Laboratories. 1978, p 82


700

R = [(l-A)/(l+A)]

-100

RT n -90

B 1 0' 1 o6 1 os 1 0' 10 Cycles to fracture

Ti-6242: Fatigue properties at 425 OC Specimens were I mm (0.040 in.) sheet duplexaMealedat900oC(1650oF),30min,AC+785oC(1450oF), 15min,AC. Axial fatigue: tension (sinusoidal). Surface: mill finish. Frequency: 2500 cycles/min. nst temperature, 425 "C (800 OF). Source: AML-TR-67-41; Apr 1%7;reportedinAemspaceSr~crural MeralsHdbook %14,Ccde3718,Bat- telle Columbus Laboratories, 1978. p 83

PI , , , , , ..., , . , , , ,.., , , , , ..., , , , , , , J

Duplex Annealed Bar

1 - I

:f 480 "C (900 O F )

3poI , , , , I o4 1 o5 1 o8 1 o7 I 0'

Cycles b failure

-2: RT and 480 'C Patigue properties Specimens were 28.5 mm (1.125 in.)diameterbarduplexannealedat970'C(1775°~, 1 h,AC+595OC(l100OF), 8 h, AC. Ultimate tensile strength, 1006 MPa (146 h i ) ; tensile yield strength, 958 MPa (139 hi); mmh, rotating beam tests. Source: DMIC Data Sheet; Jan 1%7, repotted in Aemspace Structural Metals Handbook, hl4, Code 3718. Battelle Columbus Leboratories, 1978, p 83

f 300- B 'I 2oo- 5

'9

I d

o (r 67OoC(1775*F) "I -

rn

1 o4 1 o3 1 oe 1 o7 ld Cycles to failure

T1-6242: Fatigue properties at 480 O C Specimens were 28.5 mm (1 I 125 in,) bar, duplex anr!ealed as indicated. Rotating beam test results reported at 480 'C (900 "F). Source: DMIC Data Sheet; Jan 1967: reported in Aerospace Smrctuml Met- 01s Handbook, Vol4, Code 371 8, Baaelle Columbus Labaratodes, 1978, p 84

T I ~ A C ~ S ~ ~ Z ~ - ~ M O ~ . O ~ S I / 235

100

Duplex Annealed Forgings

Notched Specimens, K, = 3 , , , , .... ) , , , , ./, , , , , .,, , , , , ,,,, ~ , , , , ,

I 4 315"C(8Oo0F)

g = 1

j l 2 0

60 300 , , , , , , , , , , , , , , , , , , , , . , , , , , , , , , , ,

lo3 1 0' 10' 1 oe 1 07 Cyoies to failure

V-6242: Fatigue shength at uw) *C Specimens were compressor disk forging (three forgings from three different heats) duplex anmaled at 955 "C (1750 OF), 1 h, AC + 5% "C (1100 OF), 8 h, AC. Axial tension, R = 0; frequency, 1800 cycledmin. Source: Ram& Whitney Data; June 1972: reparted in Aemspoce Stnrc. rural Metoh Handbook, Vol 4, Code 3718, Battelle Columbus Laboratories, 1978, p 84

10' los loe 10' id 1OD 1olo cyd@ to failure

Ti-6242: High-hPqaency fatigue properties Specimens were 19 nun (0.75 in.) barduplexannealedat955 "C(1750DFx 1 h,AC+595(1100"F),8 h,AC.Axial fatigue,R=-I. Frequency: 13.0WzatRT. 13.4kHzat48O0C(90O0F). Failure criterion: Crack grown to nearly half of specimen cross d o n . Source: NASA TR-72618; July 1969; reported in Aemspace Stinchrml Metals Handbook, b l 4 , code 3718, Battelle Columbus Laboratories, 1978, p 84

I i

P 0 0 0 103 1 0' 10' 10' 107

Cycles to fallure

lI-6242: Fatigue strength at 455 O C Compressor disk forgings from W different-, treated at 955 "C (175OOF) f o r 1 h AC. 595 oC(1100 'TI for8 h, AC. Axial tensiw R = 0; frequency, ls00 cycledmin. Source: Ratt & Whitney Data; June 1972;repbnedinAemspace StmtumlMetals Handbook, Vo14,Code3718, Battelle Columbus Laboratories, 1978, p 84


Impact Toughness

chrpyv-ml4ch imlrettoIabmm J R*lM Berthamem

595 OC (1 100 'ph 8 h, AC (b) 30 22 28 21 28 11

95SoC(1750T), lb,AC+S9SOC @) 38 28

34 25 35 26

1035 OC(19OOT), 1 h, WQ +595 T @) a 6

a 6 a 6

8pecL#p

( I 100 OF), 8 h, AC

(1100 91,s C AC

1035 OC(19ooop), 1 b Hd:+ 595 OC (c) (d) 28 21 (1100 "p), 4h HeC

0 0.05 0.1 0.15 02 0.26 S l l h , wt%

Ti-: Impmt tougbnm VII silicm content at 4 OC Effect of silicon content on -40 OC (-40 OF) Chsrpy.V-nc&h impact emqy of duplex amtealed 15.8 mm (% ia)bartmted 15 Dc (25 Dp)belowtraaw fop 1 b, AC, 595 OC (1100 OF), for 8 b, AC. Source: Armpan Stnrctuml Metals Hrmdbook, %I 4, Code 3718, Banelle Columbus Labotatories, June 1978

451 I

0.1 0.16 0.2 0.25 0 3 0,38 Oxygen content, wl%

T16242: met3 oforypm on errt IIUpect tuugwssm ofoxygen Coam on r o o m - t e r n m C w y V-wtch impact enargy for m u m b l e electrods mebd cashp. Spsclmsns w m amsumable eletpods skulls melted in water- cooled coppa crucibles and cast into amgs~eo-lined ceramic molds. SIllndard

chi& to final dimmion8 following beat treatmeat of 595 'C (I 100 OF), 8 h AC or HeC. sourcC: Acmpace Srnrctuml Metals Handbook, W4, Code 3718, Bat- telle Columbus Lsbonrtoricw, June 1978

C m V-~otch bara a t 0.25 0.38 (0,010 to 0.015 h) OW md IIU-


Tim8AI-1 Mo-1 V Common Name: TI1811 UNS Number: R54810

Ti-8Al-1Mo-1V (TI-81 1) was developed around 1954 for high-temperature gas turbine engine applications-specifically, compressor blades and wheels. It is now available from most titanium alloy producers. Ti-81 1 has the highest tensile modulus of all the commercial titanium alloys and exhibits good creep resistance at tempemlures up to 455 OC (850 OF). Ti-811 has a room-temperature tensile strength similar to that of Ti-6Al-4V. but its elevated-temperature tensile strength and creep resistance are superior to those of other commonly available alpha and alpha+beta titanium alloys.

Chemistry and Density The Ti-8Al-1Mo-1V alloy contains a relatively large amount of the

alpha stabilizer, aluminum, and fairly small amounts of the beta stabi- l i m , molybdenum and vanadium (plus iron as an impurity). Although this alloy is metallurgically an alpha-beta alloy, the small amount of beta stabilizer in this p d e (1 Mo + 1V) pennits only small amounts of the beta phase to become stabilized.

Density. 4.37 g/cm3 (0.158 lblins3)

Product Forms Ti41 1 was developed for engine use, principally as forgings. Avail-

able forms include billet, bar, plate, sheet, and extrusions. Forming of sheet at rmm temperature is more difficult than for fl-6A14V, and severe forming operations must be done hot. Ti-8 1 t has good weldability like other alpha or near-alpha alloys. Weldments have similar swngth but lower ductility in comparison with the base metal.

Product Conditionhficrostructum Ti-8 11 is characterized as anear-alpha alloy with several alpha-alloy

characteristics such as good creep strength and weldability. However, the alloy does have alpha-beta characteristics such as a mild degree of hardenability. Ti-8 11 is generally used in the annealed condition, where lamellar alpha morphology from ttansfonned beta is produced by duplex and triplex annealing for enhanced creep resistance.

A ppiica tions Ti-81 1 is used for airframe and turbine engine applications demand-

ing short-term strength, long-term creep resistance, t h m a l stability, and stiffness. Ti-81 1 is piedominantly an engine alloy and is available in three grades, including a “premium grade‘’ (triple melted) and a “rotating grade,” for use in rotating engine components.

Use Limitations. Like the alpha-beta alloys, Ti-8 11 is susceptible to hydrogen embdttlemmt in hydrogenating solutions at m m temperature, in air or reducing a l m o s p h at elevated temperatures, and even in pressurized hydrogen at cryogenic tempemwes. Oxygen and nitrogen contamination can occur in air at elevated tempratum and such contamination becomes more severe aa exposure time and temperature increase. Ti-811 is susceptible to stress-comsion cracking in hot salts (especially chlorides) and to accelerated crack propagation in aqueous solutions at ambient temperatures. The environment in which this alloy is to be used should be selected carefully to prevent material degrada- tion.

Tl IAI -1 M e 1 V SpecHicdona and compositions

R m h Desimtbn DesriPtion A1 C Ire H Mo N 0 V Otber UNS R54810 8 1 1 balm China

bi - ConwrPtbn,wt%

n-8Al-lMo-lV 73-83 0.lmax 0 . 3 1 ~ 0 .015m 0.75-1.23 0.04max 0.15max 0.75-1.25 Sial5max;balV

spein UNE 38-7 17 USA AMS4915C

AhiS4915F AMS4916E A M S 4 9 3 s AMS 49558 A M S 4 9 7 x

L7102 Sh Sap PI! Ber Ex! Ann 7.35-8.35 0.08 0.3 0.015 0.75-1.25 0.05 0.12 0.75.1.25 0TOA;balTl

Sh Sbp Plr Ann 7.35-8.35 0 . M W O a 3 ~ 0.01Sma~ 0.75-1.25 0.050)max 0.12ma~ 0.75-1,25 OTOAIIM;YO.WS~;

Sh StrpPlt Ann 7.35-83 0.08 03 0.015 0.75-1.25 0.05 0.12 0.75-1.25 OTO.4Y0.005;balTl ShSbpPlI PAM 7.35-8.35 0.06 0.3 0.015 0.75-1.25 0.05 0.12 0.75-1.25 OT0,4;YO,WS;bdTi Ex1 Rng SHT/Stab 7.35-835 0.08 0.3 0.015 0.75.1.25 0.05 0.12 0.75-1.25 OT0.4YO.WS;bslV Weld Fill Wu 73-8.35 0.08 03 0,Ol 0.75-1.25 0.05 0.12 0.75-1.25 OTO.4;YO,WS;balTl

OE0.1max;balTI

Bar WuRng Bil SHT/Stab 7.35-8.35 0.08 03 0.015 0.75.123 0.05 0.12 0.75-1.25 OT0,4;YO,O[n;baln

USA (coatiInbed) A M S 4 9 7 x Frg Bil SHTBtab AWSA5.1470 ER[1-8AI. 1 W I V Weld Fill Met MILF43142A CompS Fm Am MET41556A W A - 4 MILT-90461 W A - 4 ShShpPlt AM MILT-90470 n-BAl-lM~lV BarBilDupAnn SAEJ467 m-&l-l

7.35-8.35 0.08 0.3 0.015 0.75-125 am 0.12 0.7s.i.25 0~0.4;~o.m;baln 7,35-8.35 0.05 0.25 0.008 0.75-1.25 0.03 0.12 0.75-1.25 balm 7.356.35 0.08 0.3 0.015 0.75-1.25 0.05 0.15 0.75-1.25 OTOA; baln 7.35.8.35 0.08 0.3 0.015 0.75.1.25 OM 0.15 0.75-125 OT0.4;balTl 7.35.8.35 0.08 0.3 0.015 0.75.1.~ 0.05 0.15 a7s.i.u OT0.4balm 7.35-8.35 0.08 0.3 0.015 0.75-1.25 O# 0.15 0.75-125 OT0.4;YO.WS;bPln

8 0,04maxO.l5max 1 0.02m 1 Si 0.07 m; M 0 . a m; balTi

M I - 1 b l V / 239

TCBAbl Me1 V: Commercial cornposhlono

BpcdlLotba De&mtbn DBleriptka Al C Fe H Mo N 0 V other

Fmsce uginc UTA8DV BarFrgDA 7.3.83 0.08 0.3 OM)6.0.015 0.75-1.25 0.05 0.12 0.75-1.23 ball7

D*lacheT ContimetAIMOV8-1-1 pltBuF~&iU 72-85 0.08 03 0.015 0.75-1.25 0.05 0.12 0.7S1.25 ball7

JPprn Kok €38-1-1 BUFrgsTA 7.35835 0.3 0.015 0.75-1.25 0.05 0.12 0.75-1.25 bdl l USA C b ~ E x t . 8Al.lM0-lV OREMBT m-6-1-1 RMI R M 8AI-IMO-lV Mult F a m ~ DA 73-83 OM 0.015 0.75-125 OM 0.12 0.75-1.23 W l l Tim m m 8 - 1 . 1 Ann 7.35-8.35 o.ol)ma~ 0 . 3 m O.OISIW 475-1.25 0 . 0 5 m a ~ 0 . 1 2 1 ~ ~ 0.75-1.25 batn

TMACl Mo-1 V TLplcal rotatlng bmm fatigur ol rolkd lwrstock

stma Condttbn Mps Lui cyck!$to callurn Simplex &(a) with a 724 105 45,000aod55,W 937 MPa(136 kri)UTS 689 100 50,000 and!HO3Mpa(131ksi) 655 95 200,000 TYS 620 90 14(x000

Duplex aNwl@) with a 724 105 85,ooO 1013MW(147 ksi)UTS 689 100 140,000 wd951MPa(l38ti) 655 95 200,000 and 300,ooo WS 620 90 1,100,ooO and 3,000,000

(a) 780 'C (1400 T), 24 h, AC. 6) W'C ( B O O OF), 4 h, AC t 1140 'c (loo0 OF), 24 h, AC. Eburm:AllOy Digest, Jan 1962

Unnotched Fatigue L ib

RT

Note: atressesarebesed on net 8ectlon

Fatigue life, cydes

tion: The equivalent s a s s model may provide umalistic life pdictions for s m s ratios beyond those represented.

n-8AI-lMerV:Best-fltSIN~rvvesforUnnotchedBeetntRTSeetable. C ~ U -

Ti-8A1- 1hb 1v NIA NIA 1.3mm(0.050in.)sh~ mplex- lWA NIA NIA 1014.9Mp1(147.2 hi) 934.9Mpe(135.6kd)

RT, 200 O C (400 OF)& 345 OC (675 "F) Air Ractun AxiaJ(ascflyreafwRntio) Lcq-aamvasedirah Unnotched, 19 m (0.75 ia) rrt wldm mwpickhd N/A 1800eyclcsmdn NIA NIA


to5 10' lo6 10' 10' 10'

345 'c K.l.0 180

Fatigue Me, cycles

Ti-8AI-1Mo-1V: k t - f l t S/N curves at 200 OC See table on previous page for test conditions. UTS at 2M) 'C (400 O F ) was 825 MPa ( 1 19.5 hi). Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented.

FaUQue Me, cycles

T i - S A l - l M ~ 1 V Best-fit S/N curves at 345 OC See table on previous page for test conditions. UTS at 345 "C (650 "F) was 760 MPa (1 10.2 hi). Caution: The equivalent stress model may pmvide unrealistic life predictions for swss mtios beyond those represented,

Notched Fatigue Lib

TkSAI-lMo4V: Fatigue crack growth data Duplex annealed 1,27 mm (0.05 in.) specimens

Cmck initirtbn(a) Cnrkgrowth(b) kion Purentage -rime

MPE lui Me, flighb Itbrhta tif& night# flights wfllrhts

172 25 137 158 127 Mx) 93 10 160 I 207 30 18 540 13 300 12 s 240 28 24 I 35 7 412 5303 71 2 170 29

meanitRIIs FPligW OltOtDl R M , of Wal

Aeahted testsat morn temperatum(c)

172 25 105 988 207 30 57 290 241 35 22 290

Accelerpted testsat 560 K(c) 172 25 36 243 207 30 I2 498 24 1 35 4 580

Real-tima tests(d) 172 25 I9 014 207 30 10420 24 I 35 5 093

78 Mx) 40m 12 000

25 500

2 850

12000 8 loo

63 78

27 990 16 990 10 290

10 740

I 7K)

7 010 2 320

26 30 46

30

38

31 22

(a)Forcrackaextending lmm(0.04 in,)fmmthenotch.(b)Forcnurksfram lmm(0.04h)longuntilfailure.(clOneteet ateachdesign~e.(d)Medianvaluebomtellt. Source: LA. Imig, "C~sckcrrowthinTi-8Al.1Mo-1vwith Real-Time and AcceleratedFlighbbyJlighthading," Fatigue C w & Growth underSpectrumLoade,llSTM~ 696,ASTM, 1976, p 251-264

TWI -1 Me1 V / 241

'i p I 300 P

Note: stresses are baaed on net section

0,lO 1 1

lo3 10" 105 loE 10'

0.10 100 . . . _ . . . . I . . ..... .. . . ...... I . . ._

103 lo4 105 loE 10' 108 Fatigue life, cycles Fatigue Me, cycles

Ti-sAl-lMdV: Best-flt S/N curves for notched shwt at RT See table for test conditions. Caution: Tk equivalent s o w s model may provide unrealistic life predictions for stress ratios beyond those represented Source: MIL-HDBK-5. Dec 1991

TCSAI-lMo-lV: BestAt Spl curves at 200 OC See table for test conditions. Caution: 'Ihe equivalent smess model may provide unreaiistic life predictions for stress mdos beyond those rrpresented. Source: MIL-HDBK-5, Dec 1991

lost condttlonr for best-flt SN c u m

l b t ~ C o m m o n N a m e : ?I-8Al-lMc-IV Specifation DaigMtim: N/A i3xnpxirion: NIA Rodun form: Heatvupment: Duplex an& RTmcibsIrengWdrngation: 1014.9Mps(l472bii) ftT yield cmgth: 934.9Mw(135.6kri) TsbtPammdm Test tempaanue: Test e n v l m n t : Air Failure crimion: FractuFe Loading conditkm: Axial (see figures for R rn-) Specimen wientation: LongtransvenegraindiRctioa

1.33 mm (0.050 in.) sbat

RT, 200 'C (400 "P), and 345 T (675 'FJ

SpecimcnpXWtly: Notched, hole type, Kt I: 2.6; 38 111111 (1Mo h.) width: 31.7 mm(1.21X)in.)~~,6.4mm(O.250 in.) dismeter hole

loa lo' 10' 10' 10' 10' Surface: HN0yHFpickle.d Fatigue Me, m a Gauge length: N/A

Fnquency: 1800cycleshnin Ti-8A.I-1Mo-1V: Best-Kt S/N cum at 345 OC See table. Caution: h e quiva- w r w m MIL-HDBK-5, Dec 1991 lent stress model may provide unrealistic life predictions for stress ratios beyond those represented. Source: MILHDBK-5, h I991

1 o5 1 0' 1 os 1 oe 10' c y c h b failure

TT-8Al-lMo-lV: Notcked fatigue at low temperatures 1 mm (0.04 in.) sheet duplex annealed 1010 'C (1850 OF), 5 min, AC + 745 OC (1375 OF), 15 min, AC. Source: Aemspace Strucruml Metals Handbook, Val 4, Code 3709, Banelle Co- lumbus Laboratories, 1%

A A 345 'C (SSa 'F)

lo4 10' 1 Cycles to failure

TI-SAI-lMo-IV: A M load sharp notch fatigue Duplex annealed 0.635 mm (0,025 in.) sheet, 1010 'C (I850 OF), 5 min, AC t 745 OC (1375 "p), 15 min, AC. Notched on both sides after annealing with 60" notch. Source: Aemspuce Stmc- turn/ Metals Handbook, Val 4, Code 3709, Benelle Columbus Labonrtaries, 1966

242 I ntanium A I I O ~ Fatigue ate

Implant Material Fatigue

Rotating bending iaugw RI -1

10' 1oS 1 0' 10' d Cydes to failure

TlgAl-lMo-1V:Fatigue h salt s~lstloa Source: M. Levy, era/., The Corrosion Behavior of Titanium Alloys in Chloride Solutions: Materials fw Surgical Im- plants, in nrartium, Science and Technology, R.I. Jaffee and H.M. Bum, Ed, 1973, p 2459-2474

Forged Fan Blades high AK levels, but caused a significant inaease in crack-growth rate at - intermediate AK levels. Comparison of the data with results forconven-

rates for forged specimens were nearly the sBme as those for the tionally rolled specimens.

Fatigue-crack growth Of n-81 at ambient in both tionally roll& n-811 mateid that the fatjgue-k grab room air and 3.5% NaCl solution for compact-tension specimens made from forged first-stage-turbine fan blades are shown in the accompanying figures. Environmentnower ftequency had little effect at low and

1 10 id Applied stress-intensity factor range,

MPadm

Ti-8AI-lMc+lV: Crack growth in lan blade speelmens Specimens were cut from blades to simulate suspected in-service fracture pth. Source: Reported in MCIC-81-42 from W.H. Cullen and F.R. Stonesifer, "PatigueCrack-Growth Analysis of Titanium Gas-Turbine Fan Blades," NAVAIR, NRL-MR-3378, Oct 1976, ADA031836

l l 4 A l - I Me1 V I 243

Environmental Effects

Distilled water and 3.5% NaCl

< ' / / z, Air '

I

1 10 id ~ 4 , MPaJm

TI-8AI-lMo-lX Crack growth va envlronment Source: H. Doker and D. Mum, Influence of Environment on the Fatigue Crack Ropagation of l b o TI&- durn Albys, in The Influence of Environment on Fatigue, hstitution of Mechani- cal Engineen, London, 1977, p 123-130

Stress intensity factor range, ~ 4 , kaiJin.

R = 0.87

Transverse grain

Ti41 1 duplrx rnnollod Room air

A 3.5% NaCl soiutlon m CP7SA mmkd

O Room air A 3.5% NaCl solution

25 30 38 40 45 %o 55 Qo 65 70 75 Stress-intenshy Eactor ranee,

A& MPaJm

W3Al-LMo-lV: C m k growth M CP tlWum Source: M.J. Blackbum et aL, BceingReptD1-82-1054, June 1970

' I ' ' Duplex annealed, 3.5% NaCi

* Beta annsakd, 3.8% NaCi, 5 HI

dA , ' 5Hz ' 0.1 Hz

10 160 StrsasJntensity factor range,

(AM, MPaJm

'TI43ALlblV: hShdn&m and conosSm patiSue ConoSion-fatigue crack growth ram in 3.5% NaCl solution for duplex annealed and beta annealed micro- stmctures show & expected improvement horn transformed ~t~ctllres of beta treatment. Source: G.R. Yoder,L.A.Cooley,andT.W.Croobr,"lmprovementof Environmental Crack Propagation Resistam in Ti-8AI-IMc-lV Through Mi- crosauctural Modification." Final Report No. NRL-MR-3955, Mar 1979, ADA069084


Effect of Frequency

1000 L

1 10 1 02 A!$ MPadm

I ' I O D Lo 30 40 50 607080 100

AU, * S I m

Ti-8AI-lMo-lV: Effects oPhPquency in a sbrss-corrosion-inducing environment Source: D.A. Meyn, Metall. Trans., W 2 , Mar 1971, p 853-865

TI-8AI-1Mo-IV: Effect of frequency on VB AK Effect of frequency on dddN V e n u s AKcurves in 3.5% sodium chloride solution. All fatigue tests were mn at R = 0.1 with sinusoidal waveform. Source: H. Doker and D. Muns Influ- ence of Environment on the Fatigue Crack Propagation of ' h o lltanium Alloys, in The Infrwnce ofEnvimnmcnron Fatigue, Institution of Mechanical Engineers, London, 1977,p 123-130

lmpact Toughness n-8AClMo-lV Eftects of rolllng temperature on Charpy impact toughners

1010

1035

1850

1950

RT 93

205 3 I5

m 93 205 315

11.5 12.9 16.9 25.1 39.3 16.9 23.0 37.3 4.1 59.6

8.5 9.5

12.5 18.5 29.0 12.5 17.0 n.5 34.5 44.0

S0uree:Alloy Digest, Jan 1962

M A C 1 Mo-1 V I 245

Fracture PropeWes An acicular a from p fabrication or heat treatment improves frachrre

toughness in air but has less of an effect on fracture toughness in salt water. Toughness in salt water is dimtionally sensitive (see figure).

1 .& Longitudinal 43 MPadm, 38 kshlin. I-

44 M W m , 40 kaidin.

40 MPadm, 37 ksidin

0.4

10’’ 1 10 id 1 Time to failure, min

TI-8AI-IMo-lV: S-rroSim clusceptibility Stress-corrosion susceptibility as a function of s p e c i m orientation in 13 mm (0.5 in.) e n d e d plate. Three- point-loaded notched bmd specimens. Source: R, Woad and R. Favor, 7Tianirrm Alloys Handbook, MCIC-HBM, Batnlle Columbus Laboratories, 1972

TI-8AI-1 Yo-1 V: Typical toughnerr, a reom tempomtun

1 . 2 3

\

Tomlonal ioadir 3.5% NaCl and 10 ppm As a 0.8

9.6% NaCl and 10 ppm As 0.4

10’ 1 10 lo2 1 os Time to failure, min.

TMAl-1Mo-1V: SCC rtsltclnrePorbend~gortorekaArsenicaWitionswere used to facilitate hydrogen entry and were c a d 4 out at -500 mV (SCE). The lower resistance in Mode I to stress-corrosion cracking WBP taken as an indication that hydrogen played an important role in the cracking process because in Mode I, a state of hymWtatic tensile stress exists ahead of h e crack tip, which was thought to promote the concenhation of hydrogen. Source: M. Fontana and R. Staehle, Ed., Advances in Corrosion Science and Technology, Vol 7, Plenum Press, 1980

0 5 10 15 wrwn ~ W M , ppm

TI-LW-lMo-lV: KIX, Km, and K k w hydrogen Notched cantilever team specimens at loom temperature. Source: M.J. Bleckbwn ct aL, Baing Repit DI-82-1054. J ~ n e 1970

Thkknea Bept ywdrtrraptb K,W& K b O r l L . M i& mtannt MPP kd M h h win M h h Wia 1.3 0.05 Mulenrmled 999 145 82 I5 33 #)

DUpkXUIlE&d 930 135 176 160 55 50 13 050 Millrnncaled 999 145 52 48 22 20

Duplex annealed 930 135 110 100 35 32 hUllanmled,WQ 841 122 >110 >lo0 46 42 BST, WQ 864 126 >llO >lo0 >I10 >lo0

&we: RW. Wub, S W Cormion of Titanium Woye, in Stresu Comeion,ASM Intanationall, 1992


TI-8AI-lMo-lV Plaw-rtnm toughness-(&)

Ultimate 'RMlk Ebnga- Fror*lm tcculle strength(a) yield stmpthb) t h ( a ) , touphncs*(dL)

Condltbn MPa ksl M h ksi % hihlrm b r i h Mill annealed 999 145 930 I35 E- 10 IS1 138 Duplex annebd 930 135 862 125 8-10 n4 250

(a)Guaranteed mlnimume. Source: R. Wwd and R. Favor, 7kaniumAlloye Handbook, MCICHB.02, Battelle Columbu~ Laboratories, 1972

TI-8AI.lMo-lV E M of heal treatment on Impact toughness

'Rndle Impact toughness yield strength Air saltwater

MoteriPVeonditbIl MPa kSl MPadm win mJrn I r s i h Annealed 937 I36 70 64 26 24 fabricated 958 I39 107 98 25 23

8 heat treated 924 134 1W 95 32 29 Annealed plus exposcd48 h at 550-€03 'C 965 140 36 33 16 15

(10% I 1 10 OF) Mill annealed 97 2 141 M 46 19 18

Source: R. Wood and R Favor, 7f.toniwnAUcye Handbwk, MCIC-HB-02, Battelle Glumbus Laboratories, 1972

TIMETAL@ 1100 Ti16AI-2.75Sn~Zr~.4Mo10.45S1 Ti4 1 00 UNS No.: Unassigned

Tom O'Connell, TIMET

Ti-1 100 is a near-alpha alloy developed for elevated-temperature use up to 600 "C (1 100 OF). It was developed to be used primarily in the beta-processed (beta-worked or beta-annealed) condition. Ti- 1 100 offers the highest combination of strength, cnep resistance, fracture toughness, and stability of any commercially available titanium alloy. It is also recommended for castings.

Effectsof Alloyingand Impurities. The effects of tin, iron, oxygen, silicon, zirconium. molybdenum, and aluminum on creep. strength, and stability of Ti-1 100 have been determined. The alloy development program began with the screening of over 250 compositions of button (250- g) heats. These studies identified compositions that were scaled to 45-kg (100-lb) heats to provide forged product for evaluation. The most promising of these alloys were then scaled to several 8 15-kg (1 800-lb) heats for melting and conversion studies as well as thennomechanical processing (TMP) studies. This successful progression culminated with the production and evaluation of a production-sized 3630-kg (8000-lb) ingot. The outcome of this alloy development study was a composition consisting of Ti-6A1-2.75Sn-4Zr-0.4Mo-0.45Si-O.O7~-0.02Fe(max)~

This alloy is clearly a modification of the Ti-6242-Si alloy that is so widely used today. Although the chemistry differences would appear to be subtle, they are quite dramatic in their effect on creep response, as indicated below:

a Silicon: Creep resistance is significantly enhanced u p to 0.5% silicon, but beyond that point post-creep ductility (stability) is compromised with n o further creep enhancement. Tln: Asimilar relationship exi8ts for tin, with stability sac- rificed above the 3% level. Iron: Iron demonstrates a s t rong effect on time to 0,2% creep strain at the 510 "C (950 OF), 410 MPa (69 h i ) test

I

condition, necessitating iran levels well below those typically encountered in the Ti-6242Si alloy. Aluminum: The aluminum level in the new alloy was kept at 6% due to stability problems at higher levels and strength problems at lower levels. Zirconium: Zirconium w a s kept high to promote a uniform distribution of silicides in light of the high silicon level. Thus, the chemistry of this alloy was optimized not only for creep strength, but also for stability, strength, and uniformity.

Sponge and Melting Practice. Ti-1100, due to its extremely low iron limit, requires a select grade of titanium sponge. However, sponge containing roughly 100 ppm iron (0.01 %) has been produced on a commercial basis, and no problems exist concerning raw material supply. In terms of melting, the high silicon content of this alloy calls for special controls during vacuum arc remelting, especially on the third and final melt. However, Ti-550 (Ti-4A1-2Sn-4Mo-OSSi) has a comparable silicon content, and this alloy has been successfully melted for several years.

Product Forms. Ti- 1100 has been pmxssed successfully to billet, bar, sheet, and weld wire. Forgings have been produced usingisothermal and warm die methods, and foil has been produced for use in metal matrix composites.

Investment castings have been produced. The lack of a quench requirement from the solution treatment temperature may enhance the producibility of castings. No data are available on P/M products.

Product Condition. The two standard conditions recommended for the alloy are ( I ) beta processed (T> 1M5 "C, 1950 OF) and annealed (T = 595 "C, 1100 OF) and (2) alpha-beta processed; beta annealed (T > 1065 "C, 1950 OF) plus anneal (T= 595 "C, 1100 OF),

n-1100: T L p k r m m p w h ran*

corpa#o~wt% AI 8. zr pe Mo zli QI N. C

MLnimmn 5.7 2 4 33 ... 0.35 0.35 ... ... 0..

bluirmun 63 3.0 4.5 a02 0.50 0.50 0.09 0.03 OM N d n l 68 2.7 4.0 . a . 0.40 0.45 om ... ...

Wasee and Strucftuec Typical mimstructutes fix TI-1100 include equiexd or-@ for billet and sheet stock. It also traasfonns to a Wid- manMttenorcolony a+ p smctult depending oncooling rate. The effects of m h g ratc on the transformed p slnlchue an as follows: alpha-betepiocessingwithsnonnalcoolingratcnsul~inbquiaxedpri- mary a plus tnrnsformed @ with a colony strucm pius silicides, beta processing with rapid cooling results in a WidmaneWen structure, wbaeas slower cooling after piocessing results in a colwy stnrcture.

In addition to a and p phases, various silicides exist for both a + p or p proaseed d t i o m . Tbe eilicide solvus has been measured at ba tween 1030and1065°C(1885and l95O0F).Tbe&2solwsisapproxi- mately740°C(1365 T).The~transusisnominally 1015°C(18600F).

Ternpewre, O F

1 . q I 0.7

1 0.4

./ 0.1

248 /titanium Alloy Fatigue Data

from the beta forging M annealing temperatun will subtly a f k t the creep resistance, Faster cooling (Le.. oil quench vmus air cool) will improve the high-stress, low-tempaatuure portion of the Larson-Miller plot

Temperature, OF m 400 800 800 la00 1200 1400

11.0 Y

10.0

: A at27StdFaand606°C ' O at165MPeandSQ5'C

0 200 400 800 800 Tmperature, *C

Ti-1100: Thermpl roomcleat OfMnearespadon The thermal coefficient of linsarexpmsioo (a) between 25 apd 750 "C (77 and 1380 'p) for beta-proaroed materialisgivenby:a(ppml"C)=8.12t8.17~10-~T- 1.37 X 1OmST 2 + 1O4T

Temperature, O F

200 4w 800 800 1004 l2m 1400

0 200 400 600 800 Temperatun, 'C

R1100: Tbenusl conductivity Thamal conductivity (@ behween 25 and 750 OC (77 and 1380 O F ) for bera-piocessed mataial foUm the equation: Q (Wh. "C) =6,62 t 1.27X 1V2 T

17 18 19 m 21 P= (T, 'C + 273)(20 + kg ty1oOo

Tt-1100: lLpiCplU% creep Ofbeta aDlpba rmtcrlrl

0 10020[)300400wo800m Temperature, 'C

Temperature, *F m 400 600 800 1 o o o l z Q o

0 0

1 .j J i 0 ' , . /... . , . , .... .. .. . , ..... . . ... .. ... _. ...... .. -. . .... -. . ._ ; _... ..

TIMETAL* 1 i 00 249

Fatigue Propertie, Fatigue Crack Growth. Room temperature data are shown. High-

temperature crack growth is reported in Met. h n s . , Vol24 A, p 132 1,

TI41 00: Fatigue stnmgth at lo7 cycbr

I b D I m r e streagthb) oc O F x, MR w 22 71 1 .o 655 95

3.0 250 36 480 895 1 .o ulo 72

3.0 235 34

(a) Beta forgad and annealed; teeted at 90 He;R I 0.1

Fracture Properties

Ti-1100: Fracture tounhnma of beta famed and mnealwl material

8

B

1 10 lo2 AK, M W m

Ti-1100: Room-temperature htigue crack growth Ti-1100 dtmonstnues ex- cellem crack growth resistance compared to other conventional alloys from RT to 600 *C (1 110 '0. Ieolhernrally forged plus annealed Tested at 23 *C (75 'p); 20 Hz:R = 0.1

mat h a h e i l l 1095 'C (2000DFb FAC + 595 T(1lWm 8 h 1095 'C (moO°F), OQ +595 "C(11000ph 8 h I150 "C (2100 OF), FAC + 705 T (1300 OF), 8 h I095 oC(2000°F), FAC+995 "C(1825 OF), I h + 595 OC (1 IMIOF), 8 h 1095°C(#xy)T), FAC + 1095 T (20fB°F), 0.5 h + 595 'C(I100 OF), 8 ti 995 T (1825 T), PAC +995 OC (1825 OF), 1 h +S95 OC (1 100 OF) , 8 h 995 T (1825 OF), FAC+ 1095 "C (2ooo OF), 0.5 h + 595 oC(llOO°F), 8 h

FlwtuIw (m.hm Wb)

MPlJm b i J h hfhJm kdh 62.9 57.2 43.5 39.6 63.7 57.9 40.2 36.6 53.5 48.7 45.7 41.6 64.1 58.3 53.2 48.4 71.0 64.6 48.3 43.9 39.4 35.8 3a.3 275 159 69.0 44.4 40.4

Erpord.t6bDOC ASP- (W(1ORkrWb

Note: Aeexpe&ed, the dpha-beta heat treated mpterial har the lowet hctnre toughme.

Casting, In a casting study, the strength of Ti-1100 was found to be equivalent to cast Ti-6A1-2Sn-4Zr-2Mo at 540 "C (lo00 OF), but was strongerat595 oC(llOO"F).Ti-llOOis somewhat weakerinthickcross sections than thin ones and exhibits a significant creep advantage relative to T1-6A1-2Sn-4Zr-2Mo. It also has higher low-cycle fatigue strength at 550 'C (1022 OF) than Ti-6Al-Xn-4Zr-2Mo.

Forming. IT I1 00 possesses limited cold form-ability and behaves similarly to Ti-6A1-2Sn4Zr-2Mo in cold and hot fonning. Although the a + p window is relatively small, the alloy has demonstrated superplasticity in a simulated manufacturing environment.

Machining. Ti-1100 machines essentially the same as Ti-6A1-2Sn-

Joining, Welding and brazing of Ti- 11 00 is similar to Ti-6AI-2Sn- 4Zr-2Mo.

Rolling characteristics and texture formation are similar to Ti-6Al- 2Sn-4Zr-2Mo.

SurFPee Wtments . Although matcrial-specific surface treatments have not been fully explored, Ti-1100 should behave essentially the same as n-6A1-2Sn-4Zr-2Mo.

4Zr-2M00

Forglng Ti-1100 may be hammer forged or press forged using isothwmal,

warm die, or conventional die methods. The resulting propertics will vary depending on the effective cooling rate and seain rate of the deformation process. Finer srructures will result in higher tensile strength at the expense of creep strength at high temperature%. Forging below the f3 transus followed by a beta anneal to obtain the appropriete microstructure generally is not recommended. However, early forging Operations (e.g., preform block) may be conducted in the subtramus field with the finish forging conducted in the f3 field.

As with 0th difiicult to fabricate near-a alloys, precoats or other surface coating techniques 82e essential on billet stock and intermediate forging shapes during furnacing for forging operations. Ti-1 100 may be sensitive to the excessive fonnationof acaseduringrehcating processes, which may lead to undue surface cracking in forging deformation, As with other a alloys, care must bc exercised in the use of dry abrasive grinding techniques used for crack npair.

250 / Tltrnium Alloy Fatlgw Data

Recommended Forging Temperaturea The tccommcltdcd beta

ing is not r#xrmmended for this alloy. Die tanpaatures are listed in 'Tdcal Note 4 Forging."

To achieve desired elevated-turc end creep performance charrtcteristics, 'K-1100 is designed to be beta ptrocessed mating a transformed W m a-type microstrucbue, with minimum grain boundary a Todate,thermomechaaicalproceeSing wark withthe alloy suggests that forging, followed by aa appropriaec post-forging cooling proass based on section size, and f d s t a b i i n thermal

Subtraamw 5 x - g h g a n d b e t a h e a t a i s not currently m m -

unit pressures. However, hot working above the B msus is not cumulative; thu~~ifmultipleforging steps anrequind(e.g.,prefoem block, and finish), early forgins oprations may be conducted submnsus, with the

forging rangeis 1090to 1120 OC (1990 to 2O50OF). Convtntional f q -

Creatment provides optimum popaties.

m e n d e d b e c a u s e n - 1 1 0 0 , e s a n e a r - d p ~ a l l o y , i s c ~ ' b Y W

finish forging beingconductedabove thetransps withasufMmJy high level of work.

P - m = l - andcrsck sensitivity and is conducted from atem- perature above the silicide solvus-1040 'C (1905 "p)-tO avoid exce8- sive silicide formation. mically, beta forging reducticm of 50 to 75%

m u s should be avoided. M-Forgiqg Ibtment. The post-forging cooling rate is not

highly critical, and gemrally an air cool is madent. However, fot thicker d o n fogings, faa c d h g moil quenchingmay berequid to achieve final part mechanical propercicS. Final stabihficm age thermal tnabnents may be adjusted to modify find strength properties. Stabii- zati~treapnentspngenaatlyintherangeof500to65o'c(93oto1u)o "€9,

Supra-tronerur,betatorOlnpofn-l100significenlly~Pait

raenco~f~n-1100.LowLevalsofdefoimationabovettse~

IM I 834 Ti-5.8AI-4Sn-3.5Zr-0.7N b-0.5Mo-0.35Si MI 834 is anear-dpha titanium a l b y of medium strength (typically

1050 MPa, or 152 hi) and ampenrture capability up to about 600 'C (1 110 T) combined with good fatigue resistance. Thc alloy daives its Propetties from solid-solutian strengthening, and heat treatment high in the alpha + beta phase field Tbe addition of carbon f s c i l i i treatment by widening the heat matment window (see fisure). IMI 834 has a low beta stabilizer content and therefore has limited herdenability. It d n s a good level of propaties in sections up to around 75 mm (3 in.) biame- ta, with small reductions in strength in huger eections.

Pmduct Forms and Condllioa IMI 834 is available in the form of bar, billet, plate, sheet, wire, and Castiags. IMI 834 is weldable us* all of the established titanium welding techniques. It is normally alpha + beta solution mted (15% a) and aged. Miaostnrctural characttrization ofiMI834isdiscossedinMer. Zkw.,W24A,June 1993,p1273-1280.

Applications. The major use for IMI 834 is discs aud blades in the aerospace industry. oenclalpuipose use is intended for IMI 417.

lkll834: Thermal coefMent of linear expanelon

Maocd5c&otol Tcmpcntnrrrrra(Lc tkmdamw&a

oc OF lO-/PC le/ OF mm 68-392 10.6 5.9 20400 68-752 10.9 6.1 2MMl 68-1112 11.0 6.1 m-800 68-1472 11.2 6.2 2& loo0 68-1832 11.3 6.3

T h e t h e n n a l a x p a n s i o n ~ ' O f I M I 834 &typical ofother titanium alloys Heatkatedbar

IMI 854: Beta applooeb e w e Beur msus approach curves of IMI 834, MI 829, ad n-6Al4v

Eardnw of heat treated IMI 834 is typically 350 HV (20 kg load)

NOW tensils rat& is typically 1.45 (Kt = 3). Impad Stmgth. WiCal Charpy (U-notch) impact strength is 15 J

~ ~ ~ o f I M I 8 3 4 i s t y p i c a l l y 4 5 ~ ~ ( 4 0 k s i ~ ~

or about 35 HRC.

(11 ft*lbf)atmtrmpcraaue.

inheataateddiscs.

Temperature, 'F 200 400 WO 800 loo0 1200 1400

1

IMI834hasusefulstrmgthupto6oooC(111ODF).IMI834isn- tempa9wes.'I).pically,thealloygiveslessthanO,l%~plrstics~ gerdedashavhglongtcnncreeppaformanceuptoanxlad6OOoC inlOOhoursat600oC(1110OF)underastressofl50h4Fa(21.8ksii. (1110 "p) and good short tenn performaw up to SigaifICantly higher

252 / Titenium Alloy Fatigue Data

IMI

Temperature for 0,2% strain in 1 w h , 'c

0.m rtdn

500 550 800 1

l? 16 17 18 19

P - T ( r n + lqij x loJ 834: 02 % cmep Btrsln conditions Heat treated discs or bars.

I f

1 10 id 1 o3 1 o4 Rupture life, h

IMI834:Stres1mpturepropertfeeHcatt~atedbar

Low-Cycle Fatigue

Cart IMI 834: F l t l Q U O 8tnngth at 10' CyEkr

700 1 o3 104 1 os

Cycles to failure lOe 1 o3 10' 105

HigMyck Fatigue

cast IMI w: FS~~PUS strantam at i o7 o v ~ l e r Cast IMI 884: Notched fatlaue strenath

F.tw-

Wl f 23 (36.3 f

st 14eyCler Condtibn K, MR (bi)

cast, alphatkta HIP, plus !$ BI 1070 "C , A C plus 2ha1700~C 3.6) Wrought, 50 mm (2 ir) 0 bar 2.0 340 (49.3)

Direct stnse,m nrlnimum (R =O)

3.0

lo4 Id 106 1 0' 108 c y w 10 failure

IMI 834: Bigh-cycle fstigue properder (R = 0) Heat treated bar, direct (axial) smu at m m temperature.

Crack Propagation

10-9 . . . . . . . . I 10 1 o2

Stress intensity range (AK), MPaJm

IMI 834: Crack propagation (R = 0) Heat beat4 bar, longitudinal crack direction room-temperature tests.

254 / Tibnlum Alloy Fatlgue Data

(1850 "p). M 834 is stif€= than most other titanium alloys, but it has good fogesbility at its recomnmded forsing temperaturt.

la0

0

CBSaing IMI 834 can be cast u s i q the normal techniques developed for ti@-

nium alloys. 'I).pical tensile @a of cast lMI 834 at mom temperature and at600 OC (1 110 'p) are given in tables, Cast IMI 834 givts lower

tensile ductility than the alpha-beta wrought product but gives better creep performance.

=qy& / TI-8Al-4V

I Y)

ClrZIYI894:Room=twnpmturetsnrlkpmpwth

hum %

BPT @a%) - -n eoditba MPI kd MP1 M % Cut+(a+B)HIP+1U70°CAC+2b7000C 944 137.0 1071 155.4 5 7

966 140.2 l 0 n 155.6 5 9 C a t + B HIP+ 2 h7W 'C 898 1M.3 1040 147.2 6 10

901 i w a 1oU 148.8 4 9 W g h t (15% rlphs) OQ+2 h 700 O C 50mm bar (2 in.) 950 137.9 1070 1552 13 23

w- U y l m M k d k Red-

M I Y I 8a4:Tkuib propmrtkrat6.W *C

W-P U W - R&dM

Bar (03%) Ebnptbq CODdbOU m Lpi I#ps M % %

Cart + (a+B) HIP+ 1070 'c AC t 2 h700 T 526 763 663 96.2 6 16 515 74.7 669 97.1 10 29

C w + f i H I P + P h 7 C O t 467 67.8 566 82.1 6 16 4n 68.5 575 83.5 7 16

W l o u p b t ( l S % l r l d r a ) O + 2 h 7 W ~ ~ ~ ~ ~ . ) b a r 518 75.2 682 99.0 23 52

Forming IMI 834 has v q limited cold formability, but good hot formability.

It can be prodnced in sheet and plate form. Qpical sh#t properties an Shawn (see table). Superplastic forming is also possible at about 990 O C

(1814 T).

IMI 834: Prooeltles of 2 mm sheet

Yield 8treagth UUimtetede Ebngntbn c=Q hirterfpl (03%) strength (SO mmX M ( b X

eonditbn(a1 Oricntstion m bi m hi % % Boom-tempembmepropwtfos Rolled + *Arwaled (800 "0 L 996 144.6 1114 161.7 11.5 ...

T 1014 147.2 i i m 162.5 12 ... * 102.5 "c (a/B)AC + 2 h 700 "C L 998 144.8 1145 166.2 11.5 ...

T 1009 146.4 1111 161.2 11 ... * 1060 OC (B) AC +2 h 700 'C L 947 137.4 1098 159.4 6 ...

T 963 139.8 1103 160.1 6 ... Rolled + *Annealed (800 "C) L 473 68.7 67 1 97.4 18 ... High-temperalure (a00 "c) propertlea

T 5 10 74.0 720 104.5 14 ... $1025 OC (a/B)AC+2 h700"c L 518 75.2 702 100.6 16 0.2 13

T 546 79.2 728 105.7 18 0.247

T 532 77.2 I29 105.8 12 0.064 *1060"c(B)AC +2h700 OC L 554 80.4 716 103.9 12 0.055

(a) An &rid * indicates a heating duration of30 minutan. (b)lbtal plaetic &rain PRer expcmre of 160 MPa (21.8 ksi) at 800 O C (1110 O F ) for 100 hours

Heat Treatment

IMI 834: Recommended heat treatments

Common Name: Ti47 UNS Number: R58650

Ti-5A1-2Sn-2Zr-4Cr-4Mo (Ti-17) is a high-strength, deep hardenable, forging alloy that was developed primarily for gas turbine engine components, such 8s disks for fan and compressor stages. Ti-17 has strength properties superior to those of Ti-6Al-4V, and also exhibits higher creep resistance at intermediate temperatures.

Product Conditions/ Microstructure Ti-17canbe heattreatedtoyieldstrengthsof 1030to 1170MPa(lSO

to 170 hi). It is more ductile thanTi-6A1-6V-2Sn, and it is superior to Ti- 6A14V in creep behavior. With hardenability characteristics comparable to those of some beta type alloys, Ti-17 is lower in density and higher in modulus and creep strength than the beta alloys.

Chemistry and Density Ti-17 may be classified as a "beta-rich" alpha-beta alloy, because it

Density. 4.65 g/cm3 (0.168 l b h 3 ) has a beta-stabilizer (Mo + Cr) content of 8%.

Tbll 00: Fatigue btrength at 10' cycles

'Rmpmtun Fatigue-( a) Y! OF K, m Ld 22 71 1.0 655 95

3.0 2% 36 480 895 1 .o 500 72

3.0 235 34

(a)Betaforged and annealed; teeted at 30 &,I2 = 0.1

Product Forms Ingot, billet, forgings

Product Conditions/ Microstructure Ti-17 can be processed in either the beta or alpha plus beta region,

and subsequent heat treatment depends on processing history. Special ingot melting conditions are required, particularly during the final melt, to minimize segregation of beta stabilizers (primarily chromium) during solidification. Excessive segregation of beta stabilizers can cause "beta flecks"during forging or upon heat treatment, which constitute microregions of subnormal fracture toughness and ductility. Both forging and heat treating practices must be controlled carefully to minimize the effects of microsegregation (beta flecks).

Applications Ti-17 is used for heavy-section forgings up to 150 mm (6 in. thick)

for gas turbine engine components and other elevated-temperature applications demanding high tensile strength and good fracture toughness. It is used only by General Electric.

258 / Titanlum Alloy Fatigue Data

Tl=SAC2Sn=2Zr4Mo4Cr: Spdkatbnr and Compositions

swbfffstbn Dwknatbn Derriprlon Al Cr Fe E Mo N Sn Zr otber UNS WX) 4.5-5.5 3.54.5 0 . 3 ~ 0.0125ma~ 3.545 0,Wma~ 15-23 15-23 Mn0.l ma~;CuO.lma~;O

0.08-0.13; COM w;OT 0.3 ma^; OE 0.1 max; Y 0.m mar; bal n

USA A M S 4995 BilSTA 454.5 3 5 4 5 0.3 0.0125 3.5-4.5 0.0) 1.5-2.5 152.5 MnO.1 m a ~ ; c U O . l m a ~ ; O

0.084.13; CO.OS;OT0.3; Y 0.m; bal Ti

Tb5AI-2Sn-2Zr-4Mo-4Cr: Cammerclrl Compositions

SwcifiEPtbn Deskma tbn D s r i p t k a A1 Cr Fe B Mo N Sn zr otbw Japan Kobe KSS-2-244 BarFrgSTA 4.5-55 3.545 0.3 0.0125 3.54.5 0.04 1.5-25 1.5-25 OO.Ogo.13~ballI

USh OROMBT TI-17 TIMET TIMETAL 17

Wt7: VpiCrl STA hlghcyclr fatigur (unnotchd) Laad m t r d , A = 0.95

'Ibmnenturr Madmum stress Altwastinpstm c* T OF M h lrsl m bi taeaurr 24 75 965 140 470 68.2 21,000

827 120 4G3 58.5 75,000 758 110 370 53.6 7,owloao 724 105 353 51.2 6DXWO

315 6M) 758 110 370 53.6 3 7 m 690 100 336 48.7 50,000 676 98 329 47.7 88,m 655 95 319 46.3 15,ooom 621 90 43.8 302 12a00,aM

S o w : Beta 'IItcmium Alloys in the 198O'e, RR. Boyer and H.W. Roamberg, Ed., TMWAIME, W, p 438.

-17: Typlcal STA lowcycle fatlgue (unnotched) Straincontrd.A= 1.0

aolpvl tun &rriq% *C OF plprtk ElurHE 'Ibtrl CYCktohUUrr 24 75 0.38 1.49 1.87 3,180

0.10 1365 1.465 5,040 0.03 1.23 1.26 9,650 0.02 1.135 1.155 15,400 0.01 1.04 I .05 25,700 0.025 0.97 0.995 60,600

3 I5 MX) 023 1,M 154 3,600 0.133 1.20 1.34 5$00 0.044 0.982 1.03 > 1 2 m 0.055 0.92 0.98 >56,300 0.017 0.m5 0.93 286,ooo 0.045 0.88 0.93 >16,000

&w: Beta Titauium AUop in the 1980'8, R.R Boyer and H.W. Roeenberg, Ed, TMs/AIME, W , p 9 7

Ti-5AE2Sn-2Zr-4Mo4Cr I257

101 . . . . . . ..I . . . . . . . , I . , . . . . 1 o3 1 o4 1 o6 108

Number of cycles

Ti-17: Axial Patigue of STAdiak forgings 1 - 1 7 heat treatment: 860 "C (1575 OF), 4 h, AC, 800 OC (1475 OF), 4 h, FAC, 620 "C (1 150 OF), 8 h, AC. Axial loaded, R = 0, Kt = 1; frequency, 20 cycledmin. Source: Aerospace Structural Metals Handbook, Vol4, Code 3724, Battelle Columbus Laboratories, 1976

TI-17: Typical STA i o w y c k fatigue (unnotched) Load control, A = 1 .O

24 75 1103 1069 1000 93 1 8% 827

3 15 600 8% 862 841 a34 827

160 5,000 155 10,000 145 25,000 135 35,000 130 170,000 120 290,000 130 5,000 125 6,000 122 7,000 121 13,000 120 64,000

Source: Beta lltaniurn Aby8 in the 1980'8, KK Boyer and KW. Roeenberg, Ed., wm, 1984, p 437

Fatigue Crack Growth

1 10 AK, ksi din.

100

Ti-17: Fatigue crack growth at morn temperature Alpha-beta processed spool forgings were heat treated a! 860 "C (1575 OF), 4 h, AC + 800 OC (1475 OF), 4 h, FAC + 620 OC (1 150 OF), 8 h, AC. Tensile yield strength, 1075 MPa (156 ksi); B = 1; WIB = 2; L R orientation. Source: Aerospace Structural Metals Handbook, Vol 4, Code 3724, Battelle Columbus Laboratories, 1976

258 I litanlum Alloy Fatigue Date

Tb17: Phne-stmln fncturs toughness at morn bmperatum STA

Alpbs.begpmglsed 1172 170 1103 160 1034 150

Befngnrersd 1172 im 1103 160 1034 1N

33 30 40 36 M 45

53 48 65 59 88 80

bum: Beta ?ltaniutn Alloys in the IOBIYs, RR. Boyer and H.W. Rosenbrg, Ed., mwm,IS&p,p438

TI-17: E W of nductlon ratb on fracture toughnesn of dkk lotghP

mue y k W FI.rtu?@ Reduction strengtMa) tau-@) LKr) ratb m lcsi MFa4m w4JL ~ 1 p h n - k e- + STA(C)

2: 1 1150 167 41.5 378 3: 1 1145 166 36 32.9 4: 1 1165 169 37.2 33.9

2: 1 1117 162 68.8 62.2 3: I 1103 160 61 55.5 4: I 1110 161 55.2 50.2

Beta forged + STA(d)

(a)Avemge oftwa teeta (b)% mm (1 in.) thickcompacttenaion @en. (c)W "c (1660 T) for 4 h, FAC, 800 Dc (1475 OF) fw 4 h, FAC; and 620 "C (1150 'D for 8 h, AC. (d) BM) 'C (1476 "F) 4 h, FAC; 620 "C (1160 W 8 h, AC. Sourcs: Aemspm StrudwrJ Mat& H&k, Vol4 Code 3124, Battelle Columbus Laboratories, 1976

Yield strength (0,2%), kd 140 150 180 170 180

- 2 i, p I

1100 12W 1300 Yield strength (On%), MP8

Ti-17: Froeture toughnew vs yield strength (aged) Source: Beta nianiwn Alloys in the 19805, R,R. Boyaand H,W. Rosenberg, Ed., TMWAIME, 1984, p 245. Aged to strength (8 h with temperatures from 900 to 1300 OF)

Temperature, O F 1480 1500 1520 1540 15811 1580 1600 1620 1840

8 0 ' ' " ' " ~ " " ' " " ~ ~ E

B -?

\OM MPe (ly W) YS p

Boo 825 w 876 900 Temperature, OC

Ti-17: E&et d s d u t h temperam on toughwaa 25 mm (1 in.) thick coma pact Ension specimen from457 nun ( I 8 in)diamx50mm (2 in) thickdisk forging. Indicated soiution tempmre plus 785 OC (1450 "p), 4 h, WQ + 620 '12 (1150 OF). 8 h. sourcC: Beta ntmiurn Alloys in the 198O's, R.R. Boyer and H.W. Rosenkrg, Ed., TMWAIMR 1984, p 246

G.W. Kuhlman, ALCOA, Forging Division

Ti-17 is ahigh-srrength, highly beta-stabilized, a-p (near-beta) alloy whose primary commercial application is turbine engine rotating components. It can be fabricated into al l forging product types, although closed die forgings and rings predominate. Ti- 17 is commercially fabricated on all types of forging equipment. Turbine engine disks are fre- qumtly produced using hot die or isothermal forging techniques, resulting in near-net closed die forgings with reduced final machining.

Ti-17 is a highly forgeable alloy with lower unit pressures (flow stresses), improved forgeability, and leas crack sensitivity than the a-p alloy TIbA14V. The final microstructure of Ti-17 forgings is developed by thermomechanical processing in forgins manufacture tailored to achieve specific microstructural and mechanical-property objectives. Themnomechanical processes use combinations of subtransus andlor su-

critical mechanical-property criteria. Final thennal treabaents for TI-17 forgings include two- or three-

step practices of sin& or two-step solution treatments followed by quenching and aging. Solution treatment is subtransus, at 800 "C (1475 OF), followed by water quench or fan air cool for thin sections. For forgings fabricated conventionally, a solution anneal at 855 "C (1575 OF'),

followed by an air cool, may be used to improve toughness and aeep prOpaties. Aging treatment is conducted at 620 OC (1 150 OF). Subtran- sus thcrmomechanical processes (forging and thermal treatment) for Ti- 17 forgings achieve equiaxcd (20 to 30%) a in transformed p matrix mi- crostmctws that enhance strength, ductility, and particularly low-cycle fatigue properties. Supra-transus thermomechanicat processes (beta forging followed by subtransus thermal m e n & ) achieve transformed, Widmansttitten a m i c r o s t r u c ~ that enhance creep andor fracture-related propatics (T.K. Redden, Ref 1).

Conventional Forging. The objectives in forging TI-17 are to obtain the final forging shape and desired final microstructure at least cost. Conventional subtransus (a + p) forging thennomechanical processes are most widely used in commercial engine disk forging manufacture. To achieve conventional equiaxed a structures, subtransus reduction of

p - t r a n ~ u ~ forging followed by subtransus thermal treatments to fulfdl

50 to 75%, accumulated through one or more forging steps, are required. Supra-transus (@) forging for Ti-17 may be used in early forging operations, including upsetting and open die preforming, to reduce unit pressures and ease forsins fabrication. However, higher temperature initial forging operations must be followed by sufficient subtransus reduction to achieve the desired predominately equiaxcd a strucm. Convention- ally forgedm-17 is then subtransus solution treated, quenched, and aged as noted above.

Supra-transusthennomechanical processes form-17 areusedfor selected disk applications to achieve transformed, Widmanst&en a structum for improved cre.ep and fmctumrelated properties. Successful @ thennomechanical processes for Ti-17 f-iogs include controlled p forging processes followed by subtransus solution treatment and aging. The p forging thennomechanical pmesses are particularly well suited to isothermal or hot die forging technology. Beta forging requires subtransus reduction (e.g., 20 to 50%) in early forging (blocker die) stages followed by a controlled, single @ forging step, that achieves 30 to 50% reductions. Beta forging Ti-17 requires careful cwml of forging p m - e8s conditions, particularly preheat times at temperatun, to avoid excessive prior p grain growth. Beta forged Ti-17 is thcn subtransus heat treated as noted above. Because of inherent variations in forging conditions, p forged 5-17 may exhibit more final forging product variation than conventionally subtransus forged and heat treated Ti-17 forged product.

Hot die and/or isothermal forging techniques are important can- mercial methods for fabrication of Ti-1 7 rotating turbine engine disks to reduce final component cost (hm less machining) and/or improve final component microstructural and property uniformity through improved control of forsing process conditions. The SXisymmetriC shapes and designs of such engine components are very well suited to these forging methcxls. Isothermal forging of Ti-17 disks is frequently accomplished in a single forging step from bar or billet stock, under carefully controlled supra- or subtransus metal and die temperams, levels of strain, and strain-rate profiles. Hot die fwsing, where die temperahrre approaches


but is not equivalent to metal temperature, is also used to reduce unit pressures, enhance forgeability, and produce more sophisticated final shapesin fewaforgingoperations. witheither subtransusorsupra-uan- sus forging via both of these "hot die" processes and controlled post- forging cooling rates, desired tensile strength, fracture toughness, and creep propeities can be achieved in Ti-I7 using direct aging, thus elmi- nahg the solution treatment processes (G.W. Kuhlman, Ref 2).

References

1. T.K Redden, w~ and properties of ~ i - 1 7 wOy fm AirrraR and Turbine Applicationa, Beta lTtaium in the 1980'8, R.R Boyer and H.W. Rosenberg, Ed., W A I M E , 1984, p 239-264

2. G.W. Kuhlman, et ad,, "Mechanical Property 'Mloring Tita- nium Mop for Jet Engine Applications," Pm. 1986 Znt. Con$ !tTtanium Pmducts and Applications, Titanium De- velopment Asmiation, 1987, p 122-183

Common Name: Ti4246 UNS Number: R56260

TidAl-2Sn-4Zt-6Mo CTi-6246) is a heat-treatable alpha-beta alloy designed to combine the long-term, elevated-tempenuure smgth properties of Ti-dA1-2Sn4Zr-2Mo-O.OgSi (Ti-6242S) with much-improved short-term strength properties of a fully hdened alpha-beta alloy. It is used for forgings in intermediate-temperature sections of gas turbine engines, particularly in compressor disks and fan bladcs. This alloy is used at lower amperatuns than 'IE-6242S, but should be considered for long- texm loadcarrying applications at temperatures up to 400 "C (750 O F ) and short-term load-carrying applications at temperatures up to 540 "C (loo0 "p).

Chemistry and Density Ti4246 is a solid-solution-strengthened alloy that responds to heat

tmtmcnt as a result of the beta-stabilizing effect of its 6% molybdenum content. Silicon additions (0.08 wt%) improve creep resistance. As for aU alpha-beta alloys, excessive amounts of aluminum, oxygen, and nitrogen can &crease ductility and fracture toughness.

Density, 4.65 @an3 (0.168 l b h 3 )

Tl-$AC28n4Zr4Mo: Speclficatknr and cornpolltkns

Product Forms Ti-6246 is produced by all U.S. meltem as billets and bars for forging

stock. It has also been produced and evaluated in sheet and plate form.

Product Condition/ Microstructure Special ingot melting practices must be employed, particularly dur-

ing fmal melting, to minimize microsegregation of the beta-stabilizing element, molybdenum, which could result in %eta flecks" (see Techni- cal Note 1). Forging and heat treating practices require special controls to minimize beta flecks, which could result in microregions of high strength and low fracture toughness. Beta flecks are less of aproblem for V-6246 than for Ti- 17.

Applications Ti-6246 is used for forgings in intermediate-tempemre sections of

gas turbine engines. particularly for compressor disks and fan blades and also for seals and airframe components. 1r-6246 is also under evaluation for deep, sour-well applications.

~ ~~

SJdrknHon Deoinllrebn D e a c r l M Al R B Mo N 0 sa Zr Other UNS Rli6260 6 6 2 4 t d m USA AM49818 Bar WrFqBilSTA 55.6.5 0.15 0.0125 5.5.6.5 0.04 a15 1.75-2.25 3.5-45 CO.W.OT0.4:

Y0.rn;balTi MILP.83142A - 1 1 Frgm MILF-83 142A Camp 11 FrgIiT

5.5-6.5 0.15 0.0125 5.5-6.5 004 0.15 1.75-2.25 3.M4 COI)Q,bp1Ti 55-6.5 0.15 0.0125 53-63 0.04 0,15 1.75-225 3.64.4 C0.WbalTi

SpsHlcstkil Dcrirnrtion D s r l p t b ~ Al Fa H Mo N 0 a Zr Otbcr

JW Kobt Ks6.246 BarRgSTA 5.5.6.5 0.15 0.0125 5.54.5 0.04 0.15 1.75-2.25 3.545 balm

USA Adro lS-6Ab2Sn4ZldMo Bar 5.545 0.lSmaX 0,0125 5.5-6.5 0 . 0 4 ~ 0.15maX 1,s-22 3 . 6 4 4 C0.1m;balTi Howme( ManiDMar omnet Ti4246 RMI 6AI-2Sb4Zr-6Mo Bar Bil -A 5.5-6.5 0.15 0.0125 5.5.6.5 0.04 0.15 1.75-2.25 3.54.5 C0.04;MTi TclAllVaC TUW TIMETAL6246 DA 5.565 aisma~ o.oi25ma~ 5.s.c.s a04m 0 . 1 5 ~ 1.75.2~5 3545 c0.04ma~;balm

T'i=6ACISn-rlZrgMo I261

The microsmcture of T14246 is typically equiaxed primary a in a transformed matrix; this can vary, depending on processing and heat treatment history. A microstructun with an optimum combination of strength, ductility, and toughness contains about 10% quiaxcd a @ri-

Transformation Products

a" 1" 1 10 14 los 10' io6

Time, s

Ti-6246: Continuous rooliag tr9nsPomtion and ng&g diplpam Source: W.W. Cias, "Phase Thnsformadon Kinetics, Microstructurss, and Hardenability of the 'II-6A1-2Sn-4Zr-6Mo 'IZuudum Alloy," Rp-27-71-02, Climax MolyWe- num, 2 March 1972

mary a) plus a aansfmed maaix with relatively coarse secondary a and aged @.

Beta h s u s : 935 "C (1715 OF). The 1020 'C transus in flgurc is suspect.

4 a' ! P 0 0 1 10 ioo id 10' 10'

Tlme, 8

Ti-6246: Contlnuona cooling transformation diagram Source: W.W. Cias, "Phase Transformation Kinetics, Microstructures, and Hardenability of thc Ti- 6A1-2Sn-4Zr-6Mo 'IZtanium Alloy," Rp-27-71-02, Climax Molybdenum, 2 March 1972

HiqMycle Fatigue

n e w Room-temperatun a ~ h i hugue strength at 10' oycke

A r h l m h Fatigue stm@ 10' rtJL-1 cydgWr5C-All

Bert tmalment m hl Mp. kd 870*C( 16COV), 1 h AC+595 oC(llOO O F ) , 8 h,AC 793 115 380 55 9 10 'C (I675 "px 1 h, AC +595 OC (1 100 OF), 8 h, AC 825 1zO w 50

Nokc 2.6 nun (1 in.) round duplex annealed fowinm. Bounxlleroepocs Strrrctwrrl MokJe Handbcd, Code a114,Vol4, Battelle Cdumhu Laboratoh, 1972

Tb6248: Fatigue and Bnslk data for various m l e ~ u n i condition@

h i k yidd U W h i 8 l k Etongs- WUC- St~ l t lO'Cyda pbenab 8 i M h tko, l h o f Smooth Wb#l

Condition Mpe bl Mp. ksl % -16 MPa bl MPI bi

10% equiaxed primary a +STA(b) 1116 162 1213 176 13 37 620 90 248 36

50% equiaxed primary a + STA 1151 167 1240 180 14 42 675 98 262 40 508 equiaxed primary a + STOA(c) 1068 155 1144 166 14 41 620 w 262 3a 50% elongated primary a + STA 1096 159 1206 175 10 23 75 1 109 276 40 209b elongated primary a + SW 11w 161 1206 175 11 26 620 90 282 41 Bfaged+STA 1047 152 1199 174 7 13 675 98 262 38

(a)Annealed I 706 "C(1300 OF), 14AC. &)=A- 886 'C (lSSO'F), 1 h, AC + 696 'c (1lW 'F), 8 h, AC. ( c ) S W = 886 'c (1850°F), 1 h, AC + 705% ClsooOF), 1 h,AC Souroe: J.C. W m and E A Stake, in Defarmatios he, a d

lO%equisxed primarya +anoeakd(a) 1020 148 1109 161 I5 37 620 90 289 42

5Wequiaxedprimarya+awaled 1061 154 1130 I 6 4 13 34 620 90 282 41

C?, I ~ w , Ed., Ameri#a EkhQ b M e t s l e , 1984, p 932

262 / Tknium Alloy Fatigue Data

1500..

14OC-

Low-Cycle Fatigue Lowcycle fatigue (LCF) behavior of Ti-6246 has been studied to

detennine the effect of microstructure on cyclic deformation and LCF initiation (Mahajan and Margolin, Metall. Z'hms. A, VOl13,1982, p 257- 268). Widmanswen +grain boundary a and equiaxed structures of different a particle sizes were produced in smooth bar specimens of a Ti- 6246 alloy, heat treated to produce a 0,2% yield stress of about 1100 MPa (1 59 ksi). Specimens werc cycled at room temperatun under total sh.ain control.

At low strains for both Widmanstiltten + grain boundary and equiaxed a structures, crack initiation took place ata-p interfaces and in the aged p matrix. In WidmansUtten t grain boundary a structures, pro- fuse extrusion formation was noted as well. At higher strains, cracking was more predominant at slip bands within a,

In WidmansWen + grain boundary a structures, Widmanstiltten a and grain boundary a particles provided sites at which ready crack formation and link-up could take place, thus leading to much longer surface cracks in the WidmansUm + grain boundary a than in equiaxed a structures for given cycling conditions. Beta grain size played an indirect role in development of fatigue cracks. Larger @ grains permitted longer Widmanstiltten and grain boundary a particles to form. These longer particles provided longer paths where crack growth could take place preferentially and longer surface cracks could develop,

At largerplastic strains, Widmanstiltten a colonies at large angles to the crack propagation direction served to produce multiple cracking along the or-B interfaces and to slow or change the direction of crack

-210

ISTA - - . - - -

Fatlgue Crack Growth A "I-6246 alloy containing 68 ppm H with basal texture was tested

to detennine the influence of dwell time at maximum tensile stress on the fatigue crack growth rates (see table). All of the fatigue tests were con- ductedusing displacement-controlled constant stress intensity (K), in air (relative humidity not specified), at mom temperature. The Ti4246 alloy exhibited a nominal two- to threefold increase in the total fatigue

TI- Fatigue crack growth w dwell time Basal transverse textured titanium alloys tested at 21 "C f 1 "C: R = 0.01;

IOOOC

900 I................40 1 10 iol 109 10' lo6

Number of cycles

11.6246: Low-cycle fatigue STA condition: I h at 870 OC (IMX) O F ) , w r quench,age 8 hat595 "C(1100"F)andaircoal, DA(duplexannealed)condition: 15 min a1 870 "C, air cool, then 8 h at 540 "C (loo0 OF) and air cool. All fatigue tests conducted at a swss ratio of R = 0.1 I Open symbols indicate fatigue test3; solid symbols, tension tests. Source: Aerospace Strrrchtral Metals Handbook, Code 3714, Vol4, Battelle Columbus Laboratories, 1972

propagation at both surface and interior locations. Coarse a particles, which have a small aspect ratio, are favorable for multiple slip and associated multiple cracking at the crack tip.

crack growth rate as a result of the 10-min dwell at hK = 38.5 M P a 6 (35 k s i K ) , but there was little effect on the fatigue crack growth at the lower values of AK. The small changes in the fatigue crack growth rate were due to the crack advance by cleavage during the dwell periods. The cleavage fracture was the result of hydrogen embrialement.

TL orientation; 0.3 Hz

Fni&uecreck Dwdl hW prior dolm ddrw Tots1 Vowtb (AK) to dwell, during dwall, miterdwell, W ( a b

MWrn blJln. mln rrtn/mla lrmlcytk 38.46 35.0 10 6.29 443 4.62 m. 1 21.80 25.3 45 1.38 1,29 1.28 287 23.52 21.4 45 0.9 1.0 0.9 1.01

(a) Includw arck advance during the dwell time. Soume: Metall. %ns, A, W14.1983, p 2179

TIBAI-2s-o / 263

16246: lmprcltaughne88

Fo* Watba A* ChDrpy V d Ulttutebmk

oc O F F OF eolutbD oc OF J haIM MPI lol 885 1623 mo 1525 A i r d 540 lax, 12.2 9 1241 180

595 1100 13.5 10 125s 182 oilqusach 540 lax, 10.1 7.5 12% 188

5% 1 100 14.9 11 1268 184 870 1600 Ah cool 540 lrn 11.5 8.5 1310 190

5% 1100 93 7 1248 181 O i l q m h 540 lax, 8.1 6 1489 216

5% I100 8,l 6 1324 192 915 1675 830 1s25 Aircool 540 loo0 10.8 8 1193 173

595 1100 10.8 8 1165 169 oilqueoch 540 lo00 10.8 8 1337 194

5% 1100 12.9 9.5 1241 1m 870 lm, Air cool 540 1000 12.2 9 1255 182

595 1100 12.9 9.5 I275 185 oilquench 540 1000 9.5 7 1461 212

m 1100 8.8 65 13.50 197

teapanfurr temwnturda) Cooh#trom temwnbmdbl impsatough!em SJRnnttI

Notea 411 mm (1.16 in) thick up& forplaoa (11 1 h at temperature. (b) 8 h at temperature. hum: Aempuce S t M u m l Metalti Handbook, Code 3714, Val 4, Battelle ~UMbueLaboratorieS, 1972

Fracture Toughness

m: Fnctura t O U g h m of forging8

condttba hfPa bi MPa M % MPlJm Whr, Tensik*klShnftb UltlwtetendleSh%IMll Ebnltrtka, Kr (&3

a+ 8 forged+SI;l\(a) (10% primsry a) 1116 162 1213 176 13 34 31 a + 8 fagcd + W a ) (50% Priw a) 1150 166 1240 180 14 26 23 a + 8 f m d + Irrmakd@b) (5W Pitw a) lodl 154 1130 164 13 26 23 B forged + -Ma) 1M7 152 1199 174 7 57 52

(a)886 O C (18307), 1 h,AC + 696 pC(lloO"F),AC. (b)706 Oc(lWoF), 1 h,AC. Souics: J.C. W l l h m d E A Starte, i n D e f o m t i m , P h & anddtmchm, American SodetyLrMeta41984

Ti424& Fnctun toughno88 d forging8 of eewnl forglng and h8t tmtmen! wndltlona and aectlon thkkne~~~~r

F-4 wadlln 885'C(1625'F),AC

9W T (1650 OF), AC

885OC(1625'F),AC 980OC(l800 'pX WQ 885 "C (1625 oF),Ac 980 T (ls00 "p), WQ 980 T(18OoDpX WQ

HeattRlhmntmmutb~ 870 OC (lMX)'F), 2 h, AC + S95 OC (llOOop), 8 h AC

9OOT(l650 'PX 1 h WQ + 650Dc(1200 OFX 8 h,AC 9000C(16JO°F), 1 h, AC + 6 5 0 T (1200 OF), 8 h, AC 915 'c(1675 *F), 1 h, AC + 595 Dc (1 1M) OF), 8 h,AC

9150C(167S0D,AC + 52.5 "C(975W,8 h,AC 95 'C (1675 OF), 1 h. AC + 525 'C(975 OF), 8 h , AC 915 OC (1675 'R 1 h, AC + 595 oC(llOOoF), 8 h,AC

Sectbn thick- Ultimrtetwrilcstmuth Fracture taaahnars K,. mm h MPn kd W m bhlln. Y) 2 1144 166 36.7 33.4 ... .( I 33.5 30.5 75 3 1303 189 20.9 19.1 75 3 1172 170 26.6 24.2 50 2 1158 168 5a4 45.9 50 2 1158 168 65.8 9 .9 25 1 1220 in 32.6 29 -7 25 I 1220 177 4 0 41 9 25 1 1186 172 47.5 43.3

WO 0C(16H)OFhAC 91s "C (1675 OF), 1 h, AC + 845 0C(15x)0F), 8 h, OQ + 75 3 1220 in 39.0 35.5

54 2.125 1255 182 36,3 33.1 980'C (1 Wl OF), AC 845 OC (I550 OF), 1 h OQ + 595 OC (1 100 OF), 8 h AC 75 3 1186 I72 37.2 33.9

54 2.125 1268 184 35.4 32.2 38 15 1296 188 27.7 25.2

885 T( 1625 OF'),AC 915 OC (1675 OF), 1 h, AC + 595 Dc(1100°F),4 h,AC 75 3 1186 172 33.7 30.7 50 2 1165 169 333 303 2.5 1 1234 179 29.9 273

595°C(11000F),8 h,AC

S o w : W. H8% reported in Aempce Structural Metals H a n d M , Code 3714, Val 4, Battelle Columbu Labnratorh, 1973

264 I Tbnium Alloy Fatigue Data

Ti-. Fnchrlv tough- of STA torglngr of two forging condltknr and rrnclmen locrtknr 100 120 ro 160- 180 200

120 I . ’ - ’ . ‘ ’ TI-8AI-1 M&lV 100

600 900 1200 1- 0.2% yield strength, MPa

Tim F’recture toughness vs yieM strength Fracture toughness is in part dependent on microstructure arad is higher in the presence of an acicular structure. Source: “Titanium,” Kobe Steel

Ti=6Al=4V Ti& 6Al4V, 6-4 UNS Number: R56400 (normal interstftlal grade); R-1 (extra-low interstitial grade); R56402 (filler &I)

Ti-6AI-4V presently is the most widely used titanium alloy, accounting for more than 50% of all titanium tonnage in the world, To date, no other titanium alloy threatens its dominant position. The aerospace industry accounts for more than 80% of this usage. The next largest application of TI-6A14V is medical prostheses, which accounts for 3% of the market. The automotive, marine, and chemical industries also use small amounts of li-6AI-4V (see the section “Applications” in this introduction).

Chemistry Effects of Impurities and Alloying. TIbA14V is produced in a

number of fonnulations. Depending on the application, the oxygen content may vary from 0,M to more than 0.2% (by weight), the nitrogen content may be adjusted up to 0.05%, the aluminum content may reach 6.75%, and the vanadium content may reach 4.5%. The higha the content of these elements, particularly oxygen and nitrogen, the higher the strength. Conversely, lower additions of oxygen, nitrogen, and aluminum will improve the ductility, fracture toughness, stress-corrosion resistance, and resistance against crack growth.

ELI Grade. TibAl4V is available in ELI (extra-low interstitial) grades with high damagetolerance properties, espxially at cryogenic tempaatures. The principal compositional characteristics are low oxygen and iron contents,

Ti-6AMV-Pd is a grade that has palladium additions (about 0.2 wt% w) for enhanced corrosion resistance. Sumitomo Titanium has producedthisgrade.

Product Forms TidAl4V is available in wrought, cast, and powder metallurgy

(P/M) forms, with wrought products accounting for more than 95% of

the market. The properties of these various product forms will vary depending on their interstitial contents and thermal-mechanical processing. Processing methods and characteristics of TT-BA14V we discussed in a separate section entitled “Processing.” Wrought Product Formsr.Ti-6A14V is available in a wide range of

wrought product forms (see Table). The aircraA industry uses all wrought product forms. Forgings are

usedtofabricatevariousattachment tirtings,andsheetandplateareused to fabricate numerous clips, brackets, skins, bulkheads, etc. Extrusions are not used extensively, but are used for parts such as wing chords and other parts with long, constant cross-sections. Wire is used to produce the numerous fasteners found on wings. Ti-6A14V tubing has been used for components such as toque tubes. In missile and space applications, Ti-6AMV has been used for rocket engine and motor cases, pressure vessels, wings, and generally in applications where weight is critical.

Castings. Ti-6A14V of the same chemistry as for wrought materials has excellent casting characteristics. However, the high reactivity of titanium in the molten state requires suitable casting technology and has limited the number of titanium foundries. In general terms, the mechanical and fatigue properties of castings will be slightly lower than for the wrought product, but fracture toughness, s t r e s s - m s i o n resistance, and crack growth resistance will be comparable to that of annealed wrought “MA14V.

Ti-6A1-4V castings are about two to three times the cost of superal- loy castings. The cost effectiveness depends on the size, complexity, and the number of casthrgs. Major application is in aaospace and marine use. Other industrial applications include weil-logging hardware for the petroleum industry, special automotive parts, boat deck hardware, and medical implants.

P/M Products, The major reason for using the PA4 products is to produce near-net shapes. Most of the titanium P/M effort has been with

Tl4AISV I265

TWAMk Wrought products

Mutt Sheand weight ranges Price c o m p r h ( r ) Ingot 3200 to 13,600 kg (7ooO to 30,oOO lb) ... Billet Normally lWmm(4in.)diamtoabout355mm(l4in.)diamorsquare. Billeuupto50001bhaveken I..

sold, but this is not necessarily the uppa limit. B8I Dieforging From4.5 kgto>1300kg(<l Ibto>3000lb) Plate

Sheet ~icaldimensions:Ihic);ness:0.4to4.75mm(0.016toO.l87in.); Width:915and 1220mm(36and ~,$l~b;stainlesssteel,$3nb;Al,$2-4nb;Inco718,SlOnb

Forged block

Exmsion Fmmdrclesizesofabout25 to760mm(l to30In.)dim.Minimumthicknessofabout 3mm(1/8in.) Ti,$13-15lb;U)Oseriwstsinlwssteel,$3~; 155PH,

wlre

crosksections up to 0.4 x 0.4 m (16 x 16 in.)

Typical dimensions: Thicltness: 5 to 75 mm (0.1875 to 3 in,); Width: 915 and 1220 mm (36 and 48 in.);

... Ti, $XMb; Al, $lOAb; stainless steel, W b ...

Length:1.8,2.4,aPd3m(72,%,and120in.)

48 in.); Length: 1.8,2.4, and 3 m (72,%, and 120 in.) Tube w i item ...

Available in a wide range of sizes, with maximum size related to ingot size and the amount of work that Ti, Wb; stainless steel and Al, $2.50-Mb can be impated to the f q e d block

forsmallcirclesizes,srsdabout 13mm(lD.in.)forlargecirclesizes $4-5/lb; 13-8PH,$9-12nb;Al, S 2 4 b ?Lpically mawiklured in sizes ranging from0.28 to 12.2 mm (0.01 1 to 0.480 in.) dim 1/4 in. wire: TI, $2Mb; A283, Wb; stainless steel, SISOnb;

8740,$1flb;Al7075, S2.30nb

(a) Due to ita lower density, 1 Ib of titanium is appmrdmately 1.7 to 1.8 more material by volume than 1 Ib of steel or nickel-baee d o y .

Ti-6A1-4V because it is the most widely used alloy having a large data base for comparison.

The two general approaches to titanium P/M are the blended elements (BE) method and the prealloyed (PA) approach. Blended elemental powders cost $6 to $30/lb, depending on the chloride impurity content. Chloride content ranges from 10 to 2000 ppm; powders with low amounts of chloride are more expensive. High-chloride powders cannot be used if good fatigue strength is needed.

Blended elemental P/M parts of Ti-6A14V are currently in production for aerospace and nonaerospace applications where full wrought properties are not required and where there is economic advantage to this approach. (See the section "Applications" for examples). The PA approach, however, has been less successful in establishing a commercial market. Realloyed powders are not cold compactable, and their cost is high($60to$100/lb).

Product Condition/ Microstructure Wrought Ti-6A1-4V is most commonly used in the mill-annealed

condition, where it has a good combination of strength, toughness, ductility, and fatigue. Its minimum yield strength may vary from 760 to 895 MPa (110 to 130 ksi), depending on processing, heat treatment, section size, and chemistry (primarily oxygen).

Almost all titanium castings are hot isostatically pressed (HIP'ed) to heal internal porosity not linked to the surface. This minimizes the amount of weld repair, improves the consistency of mechanical properties, and enhances the fatigue performance. Ti-6A1-4V castings are generally used in the (a + p)-annealed condition, although some special heat treatments can be used to enhance the performance of the castings in comparison to the p anneal.

Annealed Condition. Although Ti-6A14V is commonly used in the mill-annealed condition, other annealing treatments are also utilized. For example, annealing just above the beta transus, or annealing high in the a + p phase field, creates a Widmansttlaen or lamellar a + p microstructure with good fracture toughness, stress-corrosion resistance, and crack growth resistance, and creep resistance. Recrystallization annealing of wrought alloy improves tensile ductility and fatigue performance.

Solution 'keated,Quenched and Aged Ti-6AI-lVAUoy. Solution- treated and quenched alloys may either have an acicular a'-martensite structure (quenched from above ptransus) or mixed a' + a microstructure (quenched from 900-1000 "C) or mixed a" + a microstructure (quenched from 800-900 "C), of which the latter is exceptionally soft and ductile. They serve as starting conditions for subsequent aging treatments. Quenched components contain high residual stresses which may not be fully relieved upon aging at low temperatures. Such components may distort during machining. Ti-6A1-4V has excellent hardenability in sections up to about 25 mm (1 in.) thick; strengths as high as 1140 MPa

(165 ksi) may be achieved at aging temperatures between 300 and 600 OC.

Applications Designed primarily for high strength at low to moderate tempera-

tures, Ti-6A1-4V has a high specific strength (strengtWdensity), stability at temperatures up to 400 OC (750 OF), and good corrosion resistance. Cost continues to be an inhibitive factor for its use in industries where weight and corrosion are not critical considerations.

Aerospace Applications. Ti-6A1-4V was developed in the 1950s and initially used for compressor blades in gas turbine engines. Today, wrought Ti-6A1-4V is used extensively for turbine engine and airframe applications. Engine components include blades, discs, and wheels. Wrought forms are used for airframe components. In addition, the superplastic characteristics of fine-grained, equiaxedTi-6Al-4V is being used increasingly for aerospace applications. It also has good difision-bonding characteristics, which, when combined with superplastic forming, enables the fabrication of very complex structures. Significant amounts of superplastically formed and diffusion-bonded structures are used today, particularly for military aircraft.

Aerospace casting applications include the range from major smc- tural components weighing more than 135 kg (300 lb) each to small switch guards weighing less than 30 g (1 02).

Ti-6A14V castings are used extensively for large, complex housings in the turbine engine industry. They are used in a variety of airfnune applications, including cargo-handling equipment, flow divertem, torque tubes for brakes, and helicopter rotor hubs. In missile and space applications, they are used for wings, missile bodies, optical sensor housings, and ordnance. Also, Ti-6Al-4V castings are used to attach the main external fuel tanks to the Space Shuttle and the boosters to the external tanks.

Surgical Implants. Wrought Ti-6Al4V is a useful material for surgical implants because of its low modulus, good tensile and fatigue strength, and biological compatibility. It is used for bone screws and for partial and total hip, knee, elbow, jaw, finger, and shoulder replacement joints. Where fatigue properties are not an issue, the cast alloy also has had minor use as an implant product.

Automotive Applications. In the automotive industry, wrought Ti- 6A14V is used in special applications in high-performance and racing cars where weight is critical, usually in reciprocating and rotating parts. such as valves, valve springs, connecting rods, and rocker arms. It also has been used for drive shafts and suspension springs. Cast 'K-6A1-4V also has had minor use in automotive applications.

Marine applications of wrought Ti-6A1-4V include armaments, so- nar equipment, deep-submergence applications, hydrofoils, and cap- sules for telephone-cable repeater stations. Casting applications include

266 / Tltanium Alloy Fatigue Data

water-jet inducers for hydrofoil propulsion and seawater ball valves for nuclear submarines.

P/M AppHcatiom, The BE method produces a product with less than full density that can k as strong as wrought material, but that gen- erslly has lowerductility, toughness, and fatigue strength. Racess modi- fications can improve these latter properties, even making them comparable to wrought, but they increase costs.

The BE approach has found a niche for the production of near-net- shape components or of lowcost preforms for subsequent processing,

such as forging. Applications inctude sidewinder missile housing, missile fins, connectingrods, turbine bladeprefom, hex stock prefonns for fittings, nuts, rnirror hubs, and lens housings.

High cost has thus far limited potential applications of PA technology to, for the most part, the manufacture of critical aerospace components. A number of demonstration parts m now flying in the F-15 and theF-l8airplanes, but noneismadeonapduction basis.Theincreased demand for titanium aluminides in higher-tempemure applications is creating interest in PA technology of P/M titanium.

TI-BAWV and bqulvaknts: qaeclficationr and comporltionr

sJwcukak Deskmtkn DescrIptba Al C Fe H N 0 V OT Other 0.1 0.4 0.015 0.05 0.2 3.545 ban U N S

UNS UNS

h m p e AECMAprEN2517

AEcMAprEN2530 AEChfAprW31 AECMA ptEN33 10 AECMApEN3311 AECMApiEN3312 AECMApI”3313 AECMAptEN3314 AECMAprEN33 15 AECMAprEN3352

AEcMAprEN-3353 AEcMAprEN3354 AEcMAprEN3355 AECMAprp13456 AECMAprEN3457 AECMA prEN3458

AECMAprEN3467 FRW AIR9183 AIR9184 -nY DIN

DIN DIN 17850

DIN 17851

DIN 17860 DIN 17862 DIN 17864 Rurslp

GQST 19807.74

OST 1.9WXl-70

OST 1.9006Q72

w UNE 38-723

LTNE 38-723

UK BS 2TklO

BSZTA.11

BS2TA.12 BS2TA.13 BS 2TA28

BS3531Pan2 BS TA.56

R56400 R56401 R56402

Ti-P63

TaA6V FA6V

3.7164

3.7264 3.7165

3.7165

3.7615 3.7615 3.7615

w W 6

VT6L

L7301

L7301

Weld Wu

Fill Mn

ShSupPltBar Ann

Bar Ann

Frg NI-m BarAnn Frg Ann Fa NHT Bar STA Fg STA bv Cast AM

HIP Bar Wu STA Sh Ann ExtAnn ShStrpAm

Bar WirAnn P l t h Remclf NHT

Fv NHT

Bar Rod F g BIt

ShSwpPltBar

Cea Ann Plt ShSW Rod

ShPltStrp Rod

Sh Strp Rod Flg

prp Ann

W u h n

WirAPn

Sh Plt Strp FoU RodAnn

Sh Plt Sap Foil Rod Frg Ann

a t

Sh Plt SupBar EXAW

Sh Plr Strp Bar EXKT

ShSapHT

Bar

Frg FQW Wir Frg HT

pum Sm Imp

5.5-6.75 6 5.5-6.75

546.75

5.5-6.75 5.5-6.75 5.5-6.75 5.56.75 5.5-6.75 5.5-6.75 5.56.75 5.5-6.75 52-6.75

5.M.75 5,5*6.75 5.5- 6.7 5 55-6.75 534.75 5.56.75 5.5.6.75 5.5-6.75

5.5-7 5.5.7

5.5-6.75

52-6.75 554.75

556.75

5.56.75 5.56.75 5.5-6.75

5.36.8

5.5.7

5-65

5.5-6.75

5.5-6.15

5.5-6.75

55-6.75

5.5-6.75 5.5-6,75 55-6,75

5.5.6.75 5.5-6.75

4 ball 0.04 0.15 0.005 0.012 0.1 3.5-4.5 bal Ti

0.08 0.3 0.01 0.05 0.2 3.5-4.5 0.4 balm

0.08 max 0.08 max 0.08 max 0.08 max om max 0.08 Inax 0.08 m8x 0.08 max 0.1 lmx

0.08 max 0.08 max 0.08 msx 0.08 max 0.08 max om max 0.08 max 0.08 max

0.3 m 0.3 m 03 nmx 0.3 max 0.3 max 0.3 mim 0.3 max 0,3 max 0.3 max

0.3 max 0.3 max 0.3 max 0.3 lllbx 0.3 max 0.3 max 0.3 mim 0.3 m

0.0125 w 0.0125 m 0.0125 llpx 0.0125 max 0.0125 Inax 0.01-25Umax 0.0125 max 0.0125 m 0.015 max

0.0125 m 0.0125 rn 0.0125 max 0.0125 mex 0.0125 max 0.0125m 0,0125 nmx 0.0125 mru

0.05 m 0.05 max 0.05 max 0.05 max 0.05 max 0.05 ~nax 0.05 nuu; 0.05 max 0.05 max

0.05 max 0.05 mru 0.05 m 0.05 max OM max 0.05 m 0.05 max 0.05 mex

0.2 max a 2 ma^ a2 m o ~ 0.2 mex 0.2max 0.2 m 0.2 max 0.2 max 0.22 max

0.2 max 0.2 max 0.2 max 0.2 m a 0.2 m a 0.2 max 0.2 max 0.2 max

3.5-4.5 3.545 3.54.5 3.5-4.5 3.54.5 354.5 3.5-45 3.54.5 3.5-4.5

3.545 3.546 3.54.5 3.5.4.5 3.54.5 3.5.4.5 3.54.5 3.54.5

0 . 4 ~ OE0.1mex;baTi OAmax OE0.1max;balTc 0 . 4 ~ OE0.1max:balll 0 . 4 1 ~ OE0.1max;belll 0 . 4 ~ OEO.l max;baln 0 . 4 ~ OEO.~IW.;WTI 0 . 4 ~ OEO.l m;Mn 0 . 4 m OE0.1 m;bdTi 0 . 4 ~ OE0,lmax;balll

a 4 ~ O E O . ~ ~ ; W T J O A m OE0.1m;balTi 0 . 4 1 ~ OEO.1 mar;balTl 0 . 4 ~ OEO.1 max;bal’II

0 . 4 m OEO.lmax;bal’l3 0 . 4 1 ~ OE0.1 mim;bslli 0 . 4 ~ OE0.1max;bslTi

a4ma~ 0 ~ 0 . 1 max;balm

0.08 0.25 0.012 0.07 0.2 354.5 balm 0.08m 0 . 2 5 ~ 0,12max 0.071nax 0 . 2 ~ 3 5 4 5 bel Ti

0.08 0.3 0.01250.015 0.05 02 3.5-4.5 0.4 balTi

0.1 0.3 0.015 0.05 0.2 354.5 0.4 M T i 0.08 0.3 0.015 0.05 0.2 3.545 balm

0.08 0.3 0.015 0.05 0.2 3.54.5 bal Ti

0.2max 0 . 3 1 ~ . 0.015max 0.05max 3.5-4.5 balm 0.59max 0 3 m 0 . 0 1 5 m 0.051~. 0 . 2 1 ~ 354.5 balm 0.08mex 0 3 m O.Ol5max 0.05m 0 . 2 m 33-45 baln

0.08 0.25 0.007 0.05 0.015 3.5-4.5 a 3 zros:s io . is ;bal~i

0.1 0.3 0.015 0.05 0.2 4.24 0.3 SiO.15;balTi

0.1 0.3 0.015 0.05 0,15 3-5-43 0.3 ZrO.3;SiO.lS;W0.2: balTi

0.1 0.3 0.125 0.05 0.2 3.545 0.4 bdn 0.05 0.2 3.5-4.5 0.4 balm 0.1 0.3 0.125

03 0.01 V. 3.5-45;nB.lS max; mNd.25 V. 35-4.5;Ti 88.18 0.3 0.01 0.05 0.2 max:

0.3 0.01 0.05 0.2 3.5-4.5 Ti88.19max; 0.3 0.01 0.2 3.54.5 n 88.18 max; 0.3 0,OI 0.05 0.2 3.5 n 8 8 . 1 9 m ;

0.08max 0 . 3 m 0.015m 0.2max 3.54.5 baln 0.3 3.54.5 Ti 88.2 max; O+Nd.25

~~

(continued)

TI-6A14V I 267

TI.6Al-N and equivalents: rpuclflocltrons and comporltlons (contlnud)

Deuignatbn DrocrWon Al C Fe H N 0 V OT otba UK (continued) BS TA.59 DTD 5303 DTDS313 MDS323 DTD 5M3 USA AMS 4WA

AMS 4905A Am4906 AMS 4907D

AMS4911F AMs4920 AMS4928K

AMS 493K

AMS4931

AMS 4934A AMS 4935E AMS 4954D

Am4956B

AMS 49656

AMS 4967F

AMS 4985A AMS4991A AMS4993A

A M S 4996

-4996

AMs4998

AM4998

ASTM B 265 ASTM B 348 ASTM B 367 ASTM B 381 ASTMF136

AsTMF467-84 ASTMF468-84 AWS AS. 1 b70 AWS AS. 16-70

MILA-46077D MILP83142A MILF43142A MILPS3142A MILF83142A MILT4 1556A MILT-81556A MLT-81556A MILT-81915 MIL T - W M I L T - W MILT-9Q46J MILT.9047G MILT-9047G MILT-9047(3

Glade5 GredeS Grade C-5 Grade F-5

Comp 6 Comp 6 comp7 comp7 CodeAB-1 COdeAB-1 code AB-2 lLpernCompA W A B - 1 COdeAB-1 CaLAB-2

ELI mt HtBetaAM Sh strp ELIShSapPlt

Ann ShstrpPttAnn Frg AM BarWuFrg Bil

Rng Ann ELIWWr Frg Bil Rng Ann

ELIBarFrg Bil

Ex Rng STA Rng

EhhgAM F i l l t W p -

nww-arc weld

Ell Flll Met wu

mFrsm STA/Mach ResEves

BrRpRno Wh/STA PICSSW

Cast Ann Cast Ann Powd Sint Nu6

BillPowdA~

EU Bil

BLI Powd

Powd

Sh Sap Plt Ann BarBil Ann caot ELIWmghtAM

for Surg Imp Blt Sa Std BltsCrStd weldfillmst EU FillMd Wn

WIdamorpltAnn Rod

FrgAm Fa l-m ELIRgANl ELIPfgHT ExBarShpAnn EX Bar Shp STA ELI Ext Bar Ann Cast Ann Sh StrpHt Ann Sh Sap Plt STA ELISh SPp Plt AIM Ber Bil STA ELI Bar Bil Arm

MILT-90470 Bar Bil AIM

5.54.75 5.54.75 5.54.75 554.75 5.54.75

5.66.3

5.6-6.3 5.M.75 55.6.5

5.5.6.75 5.94.7s 5.54.75

554.5

556.5

5 5 6 7 5 5.56.75 5.5.6.75

5.34.75

5.5-6.75

5.54.75

5.54.75 5.5-6.75 5.54.75

5.54.75

554.75

5.5-6.7s

5.5-6.75

5.54.7s 5.54.75 5.54.75 554.7s 556.5

5.5.6.75 5.5.6.75 53.6.75 5.54.75

5.54.5 5.54.7s 5.54.75 5.54.5 5.54.5 5.5-6.75 5.5-6.75 5.5-65 5.54.7s 554.75 554,75 554.5 55.6.75 5.5.6.5

0.08 nmu: 0.2 max

0.05 max

0.05 0.08 max

OA9

OM

0.1

0.08

0.1

0.0s

0. I 0.1 0.05

0.03

0.08

0.08

0.1 0.1 0.1

0.1

0.1 max

0.1 rrmx

0.1

0.1 0. I 0.1 0.1 0.08

0.1 max 0.1 mar

0.05 0.04

0.M OM 01)8 OM Ro8 OnS OM 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08

0 . 3 ~ 0.0125mex 0,3max 0.0125m 0 , 3 m 0.01 max 0 . 3 1 ~ . 0 . 0 1 S m 0 . 3 m 0.15mu

0.25max 0,0125maX

0.25 03 msx

0.25

0.3 0.3 03

0.25

0.25

0.3 0.3 0.3

0.15

03

0.3

0.3 0.3 0.3

0.3

0.3 max

0.3 mex

03

0.4 0.4 0.4 0.4

0.25

0.4 m 0.4 m

0.25 0.15

0.25 0.3 0.3

0.20.25 0.25 0.3 0.3 025 0.3 0.3 0.3 0.25 0.3 0.25 03

0,0125 0.0125 max

0.0125

0.015 0.0125 0.0125

0.0125

0,0125

0.0125 0.0125 0.015

O X 5

0.012s

0,0125

0.015 0.015 0.01

0.0125

0.0125 Inax

0.0125 max

0.012

0.015 0.0125 0.015 0.0125 0.012

0.0125 llllu 0.0125 nux

0.008 0.00s

0.0125 0.015 0.015 0,0125 0.0125 0.0125 0.0125 0,0125 0.015 0.0125 0.0125 0.0125 0.015 0.012s 0.015

0.05 maX 0.05 max 0.05 max 0.05 m

0.03 max

0.03 0.0s max

0.05

0.05 05 0.05

0.05

0.03

0.05 0.05 0.03

0,012

0.03

0.05

OM 0.05 a05

aw

0.04 mar

0.04 rma

0.M

0.05 0.05 0.05 0.05 0.05

0.03 ma% 0.03 msx

0.02 0.012

0.D2 0.03 0.05 0.05 O M 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.0s 0.05 0.0s

0.2 max 02 mkx 0.25 max

0.12max

0,12 WmEX

0.13

0,2

0.2 a2

a13

0.13

0.2 0.2 0.18

0.08

0.2

0.2

0.2 0.2 0.3

0.13-0.19

ai3.0.19

0.136.19

0.136.18

0.2 a 2 0.29 0.2 0.13

0.2 max 0.2 nux

0.15 0.1

0.14 0.2 0,2 0.13 0.13 0.2 0.2 0.13 0.2 0.2 0.2 0.13 0.2 0.13 0.2

3.54.5 3.54.5 3.5-4,s 3 5 4 s 3,545

364.4

3.64.4 3.5-4.5 354.5

3.545 3.545 3.54.5

3.54.5

3s4.s

3.543 3.545 3.545

3.54.5

354.5

3.54.5

3.54.5 3.545 3.54.5

3.545

3.54.5

3.5-4.5

3.54.5 3.54.5 3.543 3 5 4 5 3-5

354.5 354.5 354.5 354.5

3.5-45 3.54.5 3.54.5 3.5-4.5 3.54.5 3.543 3.54.5 3.545 3.5-4.5 3.54.5 3.54.5 3.54.5 3.54.5 3.54.5 354.5

N+(W.ZS; baln baln

N+(w.n: bal n baln balm

0.4 max Y 0.005 max; OE 0.1 max;balk

0.4 YO.Oo5;balTl

0,3 YO.oo5;balTi

0.4 MTi 0.4 YO.ODS;baln

0.4 YO.W,balTI

o . 4 ~ ro.oD5max:baln

0.4 wn

0.4 Y0.OoS;balTi

a 4 Y O . W S ; W ~ 0.4 Y 0,005; bal 'I7 0.4 Y 0,005: bal Ti

0.1 YO.CO5;brlTO

0.4 Y0.ooS:balTs

0.4 YO.UX;balTi

a 4 YO.005;balTi

0.4 Si0.05;NaO.l5;Cl

0.2 MoO.1 nmx;SnO.l

0.4 yo.ax:wTi

0.15;balTi

max:zrO.lmax;MU 0.1 max;CuO.l nrax;

w;ba lm

max;baln

m; zr a1 maX; Mn 0.1nw;czl0.1msx; Y 0xK)l;bsl n

~ 0 . ~ 1 ; bal n 0 . z ~ Y ~ ~ ~ ~ ; o E o . I

0 . 2 1 ~ . YO.001 m;OE0.1

0.2 Mo0.1mpx:&l0.1

0.4 bdn 0.4 balm 0.4 baln 0.4 baln

baln

tdn tdn balm balm

0.4 baln 0.4 MTi 0.4 balm

0.3 balm

0.4 ban 03 baln 0.4 baln 0.4 balm 0.4 balm

0.4 Y0.005;balT1

0.3 baln 0.4 tm

baln

03 Yo.rns;baln 5.54.75

S z J 4 6 7 ~ ELI 6.18 0.023 022 om 0.026 0.097 baln 0.4 YO.005;balTl


T laAlJV commrrelal eauivaknts: cufnpositlons

UTA6V UTA6V

LT31 TL64 W E L I conrimetAIv64 contimetAIV64 CoorimetAIV64 ELI

DAT 5 DAT5 DT5 K W Ks6.4EI 64AT 64AT

M I 3 1 8

J

l i - W 4 V 6AI4V-ELI 6AI4V 6A1.4v Allvae 6.4 TIMmALb4

AM Frg ELI Frg PhBarFrgAnn PitBarFrgSTA ELI Plt Bar Frg Pipdn

Rod Bsr Rng Frg Ann Rod BaRng Rg STA Rod Bar- Rng STA. Plt Sh Wb Bar Ann ELIPltShAnu

STA

Sh Rod Bar BU WuPIt Ex

ELI Bar Bil En Plt Sh Strp Ann BarBil Ex p1t Sh Sap Wu Ann BarBilExPltShStrpWuSTA

An0

5.5-6.75 5.5-6.75

5.5-6.5 6 6

5,5-6.75 5.5-6.75 5.5.6.75

5.5-6.75 5.5-6.75 5.5-6.75 55-6.75 5.5-6.5 5.54.75 5 5 6 . 7 5

6

5.5.6S 5 . 6 4 7 5 5.6-6.75

55-675 6

TIMET TlMEIAL64ELI ELIAnn 5.5-65 TlMBT TIMI3ALMSTA InpBilBarPltShStrSTA 5.5-6.75

0.08 0.08

008

0.1 0.1 0.06

0.1 0. I 0.1

0.03 0.03

0.08 0.08 0.08 0.18 0.1 max 0.08 rn

0.3 0.3

0.25

0.3 0.3 0.15

0.3 0.3 0.3 0.3 0.25 0.4 0.4

0.25 0.23 0.25

0.015 0,015

0813

a015

0.013 aois

0,015 0.015 0.015 0.0125 0.012s 0.00125 0,0125

0.010.01 5 0.01-0.015 0.010.015

0.41~. 0.015m

0.07 0.07

0.07

0.05 0.05 0.W

0.05 0.05 0.05 0.05 0.05 0.05

OD5 0.05

0.0s max

0.2 0.2

o,2

0.2 0.2 0.13

0.05 0.2 0.2 0.2 0.13 0.2 0.2

0.13 0.2 0.2

0.2 m

3545 3.54.5

3.5-4.5 4 4

35-45 3.54.5 3.54.5

3.5-45 3 5 4 . 5 3.5-4.5 3.5-45 3.54.5 3-5 3-5

4

3.5-4.5 3.5-4.5 3 , 5 4 5

3.54.5 4

balm baln

balm balm balm balm balm balm

balm bal ll balm baln balTi bsln balm

balm

baln

bsln

balm

balm

balm

0.13max 3 . 5 4 5 baln 0.1 0.4 0,015 0.05 0.2 354.5 balm

As an alpha beta alloy, Ti-6A14V may have different volume fractions of alpha and beta phases, depending on heat treatment and interstitial (primarily oxygen) content. Beta is stable at mom temperature only if it is enriched with more than 15 wt.% vanadium. Such enrichment is obtained when the alloy is slow cooled or annealed below about 750 O C

(1400 OF). Slow cooled Ti-6AI4V contains up to about 90 vol% of the alpha phase.

In addition, Ti-6A14V can acquire alarge variety of microstructures with different geometrical arransments of the alpha and beta phases, depending on the particular thermomechanical treatment. These different alpha ''morphologies'' and microstructures can be roughly classified into three different categories: lamellar, equiaxed, or a mixture of both (bimodal).

Lamellar structures can be readily controlled by heat treatment. Slow cooling into the two-phase region from above the p transus leads to nucleation and growth of the a-phase in plate form swing from p- grain boundaries. The resulting lamellar structure is fairly coarse and is often nfened to as plate-like alpha. Air cooling results in a fine needle- like alpha phase referred to as acicular alpha, Certain intermediate cooling rates develop WidmansWn structures, Waterquenching from the B-phase field followed by annealing in the (a + @)-phase region leads to a much finer lamellar structure. Quenching from temperatures greater than 900 OC (1650 O F ) results in a d e - l i k e hcp martensite (a'), while quenching from the 750 to 900 "C (1380 to 1650 OF) temperature range produces an orthorhombic martensite (a?,

Equiaxed micmtnrcturea are obtained by extensive (>75% nduc- tion) mechanical working the material in the (a + @)-phase field, where the breakup of lamellar alpha into equiaxed alpha depends on the exact deformation procedure (e,g., see figure). Subsequent annealing at about 700 O C (1300 OF) produces the so-called "mill-annealed" microstructure, which gives microstructure that is very dependent upon previous working. A more reproducible equiaxed structure is obtained by a re-

crystallization anneal Of 4 h at 925 OC (1700 OF) followed by slow cooling. The resulting structure is fairly coarse with an u-grain size of about 15-20 pm.

Bimodal type microstructures consist of isolated primary a-grains in a mnsfonned beta maeix. These microseuctum arc best obtained by a 1 h anneal at 955 "C (1750 OF) followed by watu quenching (or more commonly an air cool) and aging at 600 OC (1 100 "0, The resulting primary a-grain size is usually about 15-20 pn in such "solution mted and aged" microstructures. Aging below 650 "C (1 200 OF) can also produce precipitates of alpha in previously quenched beta.

Interface Phase, An FCC crystal saucture, often called the "interface phase," is frequently observed in thin foils for electron microscopy at lamellar boundaries between alpha phase and beta phase. The inter- pretation of the interface phase is sti l l controversial. It has been reported to be a phenomenon of thin foil preparation while others claim that it occurs in bulk material as well.

Qpkal lattice parameter6 of alpha phase in slow cooled or aged Ti-6A1-4V alloy are a = 0.2925 f 0.0002 nm, c = 0.4670 f 0.0005 nm. The lattice parameters vary only slightly as a function of heat treatment because the composition of alpha is relatively constant. The room-tern- pemture lattice parameter of the beta phase in fumacc cooled Ti-6AMV has been measured as a = 0.319 nm f 0,001 nm (G. Welsch et al., Met. Trans.A, M 8 A , 1 9 7 7 , ~ 169-177). Increasing vanadiumconcentrations decrease the lattice parameter of beta, while interstitial elements increase the lattice parameters of alpha by occupying a fraction of the oc- tahedral interstitial sibs. For oxygen concenvations less than 6 at.%, oxygen increases the lattice parameters of alpha as follows (S. Anderson etal., Acra Chem. S c a d , Vol 11,1957, p 1641):

a = acJ + 7 x l O ~ d a t . % 0

c = co+ 36x l f l d a t . % O

P 3 B Material: s Ti-6AI-4V %

B

-loox -soox

T

1

1

Thermal treatment with three

1050°C

850'C

800°C

650°C

K 4% V

270/Tltanlum Alloy Fatigue Data

W w V L a k e panmeten dtw quemhlng from variour bmpsrrbuw

Q.eafb -- h a -B 9 enm C m ck am

I 950 029313 0.46813 0.15969 ,I,

9oD a29320 0.46798 0.15962 ... 850 0.29288 0.46750 0.15963 I..

800 029281 OA6l29 a i m I,.

750 0.2p299 0.467 1 1 0.15966 . I (

725 0.29241 0.46706 0.15%2 0.32530 700 a29255 0.46709 0.15%6 0.32510 650 029243 0.46706 0,35972 032295 600 029254 0.46711 0,15969 022250 5% a m 0.46716 0.15970 0.32160 so0 0.29245 0.467 I8 0.1S974 0.32145 450 029246 0.4610 0.15970 0.32150 0 02 0.4 0.6 Oa6 1 400 0.29244

&utm R clstro md L hphin, & h o h &m&6qz&e &v. MddlW., Val W, NaU, M, p 1038

e

0.467 18 0 . t m 0.32120 Oxmn, w29c

TjW4V: B e t a t t a m w v a m -tent sotlrce: A. --&- Wesoan R e m e University

10 12 14 18 18 20 vanabum,wpk

TldAEov: Lattice pcurme(er org phve varialion in lattice paramster beta phme ia n4A1-4V alloy after quenching from various hut mtmnt temperatures. sourcC: R. Casmaad L SeTaPtJh Memoins ScienijpqoK Rev. Metall., %l 63. No. 12,1966, p 1036

Tmns formation Structures HeEpOoopl do14packed martensite (a') is obtained by quenching

from above 900 O C (1650 OF) and has an acicular or sometimes fine-lamellar microstructure. It is related crystdlopphically to the alpha phase andhas sirnilerlaeticeparametas as the alphaphe.

ortkhambk mprtBzL8Lte (a9 is a ratha soil martensite that forms during quenching of beta phase with 10 f 2 wt% v d u m This occurs when Ti-6Al4V is quenched &om temperaaues between 750 and9oooC (1380 and 1650 "F). The cfmartensitecanalso fonn as a stress-inducedpraduct by straining mecastable beta,

Omega (a) Pdpitation, Oxygen suppnsses omega frmnation, and it Qss not occur in 'K-6A1-4V alloy of commatd * purity.Ifthep phase is highly enriched with vanadium (ova 15 H), cu-prwipitstes might OCCUT during low-tanperature aging (200 to 350 "c) 01 during cooling through the same temparaaue range. However, no such p i p i - tationhasbeennportedhn-6Al4v.

ThAI Precipitation The formation of II3AI (ai, has been experimentally verified in Ti-

6Al-N mntahhg less than 0.2 wt% oxygen (Met. %ns., Vot 8A, 1977,

............. I...,. -

p +a' p + a

- 1 4 a

* - 1m - . -

- : I loo0

1-

p 169-177), and it occurs in TidAI4V at aging temperatures fiom 500 to 600 "C (930 to 1100 OF) w h oxygen concentrations (still within specification limits for n-6A1-4V) are increased. Oxygen is known to nstrict the solubility limit of aluminum in the alpha phase of titanium, thus enhancing the likelihood of 1 3 A I formation. Vanadium also rc- stricts aluntinum solubility in alpha titanium. However, no quantitative dependency on oxygen concentration has been established for the d(a + ai, solvus line.

900

Them3Al precipitates arelmowntopnnnote CoeRCplenarglideon

Ofcitherplanar pyramidal glide tx coarse planar prismatic gli& in the a- { lOiO} prismatic planes, andone shouldbe able toproduceapdomhme

pluc of a 'I*lbAl4V alloy with suttident oxygen by h choice of aging imtment. At high agingtmpatum ordering should notbeexpectcdbe- cause oxygen would have a high jump hquency. (0. Welsch and W. Bunk, Me& h . A , W 13A, 1982,p889-899).Ontheothahandanalloywith averylowoxygenconcenrration(ELIgrade)shouldexhibitonlyapndonri- nmce of prismatic slip, regafdles of aging trearment

RTalrR=-l

When evaluating fatigue behavior, compsrisons should account for dif€mms m yield strength, grain size, and microstructure. There is evidence regarding TidAl-4V which indicates that superior high-cycle (lo7 cycles) smooth-bar fatigue is obtained when the slip length is small (Ref 1-5). Small slip lengths accompany a finegrain equiaxed material or by quenching from the &phase field to prodwx fine, acicular a'. There is general agreement that the Widmanstkitten or colony a + @ mi- cromcture has decidedly poorer fatigue strength. In the co~vser, equiaxed microstructure the fatigue strength is significantly Iowa, but it is still better than in the colony miaos0uchue (Ref 6). In general, all mi- crostnrctural parameters that increase yield strength and/or reduce slip length should improve HCF strength. However, variations in tcxtllrc, test methad (axial versus bending), test conditions (load ratio, fra q u a y ) , and surface-preparation methods may make comparisons diffi- Cult.

I I I

References

I I

1. M. peters, A. Gysler, and G. Lutjering, in '1Tfanium '80, Sci- ence cmd !&chmZogy, edited by H. Kimura and 0. Izumi, Vol 1, TMSAIME, 1981, p 1777.

2. JJ. Lucae, in Th!aniurn Science and Ikchndogy, edited by R.I.J~andH.M.B111.te,PlenumPrees, 1973,p2081.

*, I

coarse lMlel!aI 400

10' 1 oL loe 1 0' cyrdes to fayurn

Aged TldAI-Qv: EfCF8lmgtb ln a t r ~ ~ w i t b a brrcal texhue.Thc bimodal microstructure exhibited the highest HCP strength in air, kccause the basal planes of the smngly textured a grains are separahed from each O&L 'Ihs aggressive effect of laboratory air (about 50% relative humidity) is thought to k due to hydrogen, which is most damaging along the basal plans. MateriaVTest Pa- ramem Solution annealed at 800 O C (1470 O F ) for l h, water quenched, and aged at 500 T (930 "p) for 24 h Source: G. Utjering and A. G y h , lTranIwn Sclcnce Md Technology, Vol4. Deutsche Oesellschaft Air Metallkunde e.V., 1 W , p 2 0 6 8

7- Average grain size KT= 1.8 KT= 1.0

0

0 8

A A

T l d A C 4 V arineakd forgings T l A I - 4 V so iu th treated and aged forgings TCBAI-BV-25V solution treated and aged forging Ti-6Al-4V annealed l-in.-diem bar stodc Range of graln sire

Relationship for KT = 1 .O

3

Tl-6AI4V: Emct &a grain she on crack-hhtkm stress. Source: J.J. Lucas and RP, K o d m y , Relationship Between a Grain Size and Crack-Initiation Fatigue Strength of'IldAl-W, Metall. Tram., Vol2.1971, p 91 1-912


3. C A Stubbington, 1976 AGARD Conference5 Proceedings (No. 185), Reprinted in l'kunium and Tkanium Auoys Source Book, American society for Metals, 1982, p 140-158.

4. CA. Stubbington and AW. Bowen, J. Matel: Sci,, Vol 9, 1974, p 941. TR78-68,1978,

6. J.C. Wdliams and G. Liitjering, in Zltunium 'SO, Science and Zkchnobgy, edited by H. Kimura and 0. Ieumi, Vol 1, TMS- AIME, p 671.

6. J.C. Chesnutt, A.W. Thompson and J.C. Williame, AFML

Low-cycle fatigue (LCF) is the regime characterized by a high maximum stress in a cyclic loading situation. It is also characterized by the existence of signifcant plastic defomtion during the fatigue cycle, at least on a localized scale. Low cycle fatigue failure often occurs with a cyclic life of less than about I @ to 106 cycles.

The LCF life of Ti-6Al4V is quite sensitive to heat treatment and microstructural details. The tables illustrate the wide range of fatigue propenies obtainable with this alloy. As expected, the variations in fa-

tigue properties are accompanied by variations in otherproperties, making compromises and optimization for specific uses feasible with alloys like TidA1-4V. Crack initiation, known to consume a large portion of total LCF life, is reported (Gilmore and Imam, see table) to be very m i - tive to microstructure, with an a + anneal providing the most resistance. However, an STOA treatment of an a + p forging of a beta quenched billet offers promise but with hints of some short life tests (Chahbarti etnl., seetable),

TMAWV: Fatlguo crack lnttlstlon VI heal treatment

Battrrrbacnt strain Inngeb) MePn Midmum st.nQkddFvktbn C r c k to crack tnithtkn(b)

a-p anneal: fo.006 conional strain 84370 73,690 9,ms 800 'c (1472 'p) for3 h furnace cool (FC) to fa.012 torsional smin 9,697 9,110 386 600 *C (1 112 93, followed by air cool (AC)ta loom temperaarre

Recrystalallizmianneal: i0.006 t w s i d suain 52,840 a920 10,637 928 "c (1702 Tj for4 h, FC to 760 "C (1400 'p) a 0 1 2 I d o n a l sm 6,232 4,5w lMrs

B d M.W mrsmnal snain 42,720 35,240 5.684 foD12lwsionalswin 963 ms 184

a8 180 .Cm, FCt0482 Qc (W'D ai 372'C (702 'IW, AC

(a) Siuwidal etrain a m p h d e with a 6quency of 28.6 W for fo.008 and 0.2 I& forM.012 -La. (b) Based on fourepectamw for each heat treatmeat witb fatigue lih taken aa the cyclea to initiation of ecircunrfere ntipl crack aa Indicated by an inrrease in axial elongation bum: C.M. Gllmore and M.A Imam, 'Afankun ond 7U&m Al&ys, J.C. Wiama and AF. Belov, Ed., plenum h, 1982, p 887

LCF and tracturn toughnoas of TWAISV pancake lorglngs

UMmocB F&E

Er-2 * -stork Forging conditbn Hept Number of cycled Yield rtrmgth tfwm@cli (noaklngmditknl trntmenb to hllum[a) MPa ksi krffceiwd Tp- 1OOT f ~ 0 . S NResdoQ 965 "C fOrO.5 WQ +705 "C f ~ r 72325(b) 1038 150 1071 155 405 37

Aa rcEdved Tp- 100 "cfOr0.5 W O Q 80 I "C for 1 h'OQ + 500 'C for 13,934(b) 1113 161 1126 1633 33'3 30.3

2 MAC lasosib) 1038 150 1071 155 405 37

16769ib) 1113 161 1126 163.3 33.3 30.3 Betaqwnched Te- 16S4Cf~0.5hlResdoQ 975°Cf~0,5hFAC+801 "Cfff 32,581(~) 1087 157 1124 163 52.8 48.1

17,960(d) loB7 197 1124 163 52.8 48.1

24 MAC

1 NOQ+500"Cfm24MAC

(a )Terr tedwi tha~mt loofR. ;0 .06 ,a~cgof20cyc le~andamruimum8tresso f880~~127 .7ke i~ (b~Fai l ed ingauge .~c~Run-out .~d)Fa i l edat in~f f~ of radius and uniform emtion. M ~ l c ~ p w a m e t c r s : Bar etock of7.6 an diameter had the compodthn in weight % ofAM.1, C0.04, Fea.2.3, H.O.0061, N0.038,0~.187, X41, Y:CO.OOM). Rqbem: %iims&uchue and Mechanical Propee Optimization Through Thermomechanical Proceming in 'Ti84 and "i4-2-46 Allon" A Chakrabarti, M. Bum, D. Foumier, and 0. Kuhlman, in Sizth HbrM C o n f e r n on 32ranium, 1989, p 1389

Strain LIfe

WAI-4V extruded rod: LCF trom rhslrr straln With high shear strains, unstable microstructures, such as those provided by quenching from the solution treatment, provide greater LCF life when compared to annealed or stable microstructures. However, such unstable microstructures are not recommended for cyclic loading applications.

Mean Minimum staadud Tbernrl b u t m u i t uacal UB! devhtbo cGBArmeakd 944 429 443

900 *C (1650 'P) + WQ %I6 8917 758 927 'C (17OO'F) + WQ 2223 2142 €03

ro l~ t i~ l l - 1065 OC (1950 O F ) t WQ 23% 1633 487

(a) Raeultabased on four- (6.4 mm diam emUded md) for a nhear #trein of M.02 at 0.2 Ht. "ha u+ anneal involved holding at 800 'c (1470 W for 3 h followed by Aunace -ling to 600 'C (1110 TI. Source: M A Imam and C.M. Gilmore, Fnt&pe and Mieroetnrctural Pmperblae of Q u m h d 1p6A14V, Metdl.llun.s. A, W14A, 1988, p 288.240

843 OC (IS50 'FJ + WQ 2497 1837 717

Stress-Controlled LCF

11 25mmQkrn k r

Annealed 700 'C 71 20 . - - m m

10 lo? 1 0s 1 o4 1 o5 Cydes to tallurn

Ts-6A14V: taU-cycle fcltigw of heat-treated bar. This figure illustrates the effect of tensile strength on stress c o ~ l l e d LCF of TilAI-4V where the high strength STAcondidon gives the greatat life. Although smin controued test results are not presented, the conclusions may be different with strong correlation expected with true ductility. MateriaVnst Parameters: See table formaterial condition. 'Tbsting was performed at constant maximum load, zero minimum, fre quency = 10 cycledmin. Source: Data from J.R.B. Gilbert, MI Titanium Lbd., 1988

Cast and P/kb

TMAc4V Bar tensib propsrtkr for LCF fQum

on SD, %

F b t rtras - - bi kd 900 'C WQ + UK) T (STA 1) 146 163 15 960 'C WQ + 700 T (STAZ) 141 155 14 Annealed7WT 141 149 14

aZ+pmaf plylk Eloagntbn

Castings and powder metallurgy (Phi) products are being applied with increasing frequency, primarily for their net shape mmu- facturing CWbilities. There is an LCF Penalty for castings and PIM pmducts (see figures), however, these debits can be reduced signifi-

cantly by hot isostatic pressing (HIP) and heat treatment processing as well as improved PM processing. A compilation from 260 *C LCF tests (see figure) gives results for polished, notched, cast test bars ofTiS6A]-4V with no HIP consolidation,


1 0"

Y r o u g h t at 370 'C cast at 370 *C _ _ .

' - -Cast at mom temperature

. . , . . . , , , . . . . . , , . , . . . . , , . . , . . . . . id loa lo4 los 10) lo7

Cycles to complete separation

TMA14V: LCFolPREP-HIPP/M component& Source: A.S. Sheinkeret aL, EvalualionandApplicaCioaofRealloyed'I*ltarriumP/MPans f o r A h e S a w - h m , l n t . J . Pder ,Vol23(No, 31,1987,~ 171-176

cycles to failure

TLdAI-4V: Lon-eycle axial fatigue for notched (K1- 3.5) annealed cPstlngs (without HIP). MateriaVTest Parameters: Cast-tosize specimens were Bnnealtd 700 oC(1300oF)for2~aircoolcd,thenpolishedwithwinanddiamondpasle.andfinishmachined,Testfreqwncy was300cycleshnin.Source: DetafmmR.Dalid,AVCO Cop., reported in Aerospace Stmctural Metals Handbook, Battelle, Code 3801, p 18

lMAl-4V I275

700

Fatigue limits (or endurance limits) represent the value of stress below which a material can presumably endure an infinite number of cycles. For many variable-amplitude loading conditions, fatigue limits may be observed in the regime of lo7 cycles or more. Fatigue limits generally are influenced by surface conditions because 80 to 90% of fatigue life in the high-cycle regime (about 104 cycles or more) involves nucleation of fatigue cracks at the surface. Fatigue limits are also influenced by

Lab air, R = -1 YS = 910 MPa, 800 ppm OQ

100 O

130 Vacuum 900

P

0.2

Coarse lamellar @mm 500 1 o4 1 o5 1 08 1 o7 1 08 "'

cycles to fallure

Ti-6AI4V: Effect of microstructure on fatigue strength in vacuum. Grain size of primary a shown. The prior p grain size, which limits the length of individual lamellae of bimodal and lamellar microstructures, was 6 to 10 pn for the bimodal microstructure and 300.600 pn for the fine lamellar structure. Mater imest Pa- rameters: Annealed at 800 'C (1470 OF) for l h, water quenched, and aged at 500 OC (930 OF) for 24 h. Source: G. Liitjering and A. Gysler, liranium Science and Technology, W 4 , Deutsche Gesellschaft Nr Metallkunde e.V., 1985, p 2068

S&lal ELI grade SpeclalELIgrade

I

1. I R10.01 I

Normalgrade A ELI grade

microstructure (see figures for fatigue strength in air and vacuum). In some cases, stress-controlled fatigue limits are not observed. These cases are generally attributed to periodic overstrains and the absence of interstitial hardening as with very low oxygen levels (see figure on effect of yield strength). Also, the absence of a fatigue limit in this alloy is often associated with subsurface initiations, especially at cryogenic temperatures (see figure).

RTalr R = -1

Bl-modal (6 pm primary a)

Fine equlaxed (2 pm)

Flne lamellar

Coarse equlaxed (1 2 pm)

Coarse lamellar 4001 , , , , , , , , , , , , , , , , , , , , , . , , , , I

10' 1 os loe 1 o7 cycles to failure

Ti-6AI-IV: Effect of microstructure on fatigue strength in air. Grain size of primary alpha shown. Annealed at 800 OC (1470 OF) for 1 h, WQ, aged at 500 OC for 24 h. Source: G. Liitjering and A. Gysler, litanium Science and Technology, Vol4, DGM, 1985, p 2068

~

850k i YS = SSO MPa, 1900 ppm 0,

I I

I" Flne lamellar mlcrosttbcture

450 1 o4 1 o5 1 o7 1 08

Cycles to failure

Ti4A14V ELI: Fatigue strength a t cryogenic temperatures. Open symbols indicate fracture from surface; closed symbols indicate internal fatigue initiation near surface. M a t e r i m s t Parameters: Testing was performed at 4.2 K in a liquid-helium-cooledservohydreulic testingapparatus W i t h a SinUSOidal Cyclic load. Spechens Were taken from a-p forged bars ( 7 0 - m ~ 2 .75 -h Square) that were annealed at 700 OC (1290 O m , for 2 h. Source: Y, It0 eral., Cryogenic Ropeflies of Extra-Low Oxygen 'K-6A1-4V Alloy, in 6th World Con$ litanium, 1989, p 87

Ti-6AI4V: Effect of yield strength (YS) on fatigue strength. Decreasing the oxygen from the typical value of 0.19 wt% to 0.08 wt% lowers the yield strength and thus the fatigue strength. Oxygen levels influence the mechanisms ofprecipi- tation and hardening, which improves resistance to dislocation motion (and thus increases yield and fatigue strength). Materiamest Parameters: Water quenched from 800 o c (1470 OF) and aged at 500 OC (930 O F ) for 4 h. Source: E.A. Starke, J ~ , and 0, utjering, cyclic plastic bfomt ion and ~ i ~ ~ ~ ~ ~ , in F~~~~~ and Microstructure, American Society for Metals, 1979, p 237


Endurance Ratio Fatigue Strength and Fatigue Limits. Fatigue limits may be re-

lated to tensile strength, although the fatigue litnit-to-tensile strength ratio of titanium alloys may reveal more scatter than quenched and tem- pend low-alloy steels (see figure, Metals H d b k ) . For alloy rt4Al4V, extensive tensile and smooth-bar fatigue data m presented for different alloy conditions by Sparks and Long and summarized by Williams and Starke (see table). Using their data, regression analysis has been performed to see if a correlation exists between 107-cycle fatigue strength and yield or tensile strength. In both cases the coefllcient of correlation was smaller than 0.1, indicating that essentially no correlation exists. This tends to point out an important difference between Ti alloys and s tee ls -nmly , that the effects of microstructure and strength can be offsetting factors so that no change in fatigue performance might be observed even when strength is increased. Thus, fatigue strength may not correlate with tensile strength alone.

12c) 146 160 180 Pod Tenelk strength, ksl

120 140 160 180 2w

800 900 loao 1100 1200 1300 1400 is00 Tenslle strength, MPa

TibA1-4V: Scatter of fatigue strength v& tensile strength. Source: Merulr Handbook, %I 1,8th ed., Ptvpenies and Selection OfMetuls. American Society forMetals, 1961,p529

TMAMV Fatigue and ten8ile data for various mkmstructural~0ndlblon8

Yield PMile Strabp (smooth) -(-I

Condlbo M R kri Mpe ksi % arm. % MP1 lrsi ma bi 1056 eguiaxsd prinnvy a + m ( 8 ) 97 1 141 1068 155 14 3s 531 18 214 31 408equiaxed @narya+ arm 930 135 1013 147 15 41 579 84 255 37 IO%equiaxedprimarya+STOA(b) 978 142 1061 154 IS 41 489 71 220 32 10% q u i d primay a + m ( c ) 958 138 1040 151 14 37 606 88 262 38 50% elongated primary a + m ( c ) 923 134 1020 148 13 32 620 90 227 33 Bfw+m 882 128 992 144 11 20 565 82 220 32 Pm-qw+m 95 1 138 1054 153 10 21 606 88 186 n PForge+rnA wa 142 1075 156 10 20 586 85 220 32 lO%equisxd@narya+ann[d) 882 128 985 143 13 33 620 PQ 214 31

h l W t h strength Ehngastka, Redudonin at 10' cycka It lO'C$de#

(a) aun = 706 Ocn WAC. 6) STOA= 961 W1 MWQ + 706 'c12 WAC. (c) Water quenched off fbrging preae. (d) Lawaygen matsrial. Source: RB. spuke a d J.R Law, AFML-TR7sso1, February 1974. Data summary reported by J,C. Williams and E A Stsrke, in Deformation, Pmcwhg, and Structure, American sodety for Metals, 1984, p 826

Variation of Endurance Ratio The spread in the endurance ratio (fatigue limithltimate tensile

strength) is also documental in ASTM STP459 (see figure). Endurance ratios varied from 0.42 to 0.62 for the unnotched condition. Several of the data points which make up the low side of the band represent slow coolingratesforthebetaphase field Thedatapointforthe 1350OFtreat- ment on the low side of the band was from m a t e d containing coarse plate-like alpha, which is further evidence that the coarse plate-like alpha structures lower the endurance ratio of the Ti-6AI-4V alloy. There- fore, heavy sections of Ti-6A14, which contain coarse plate-like or even c o m e equiaxed alpha, might be expected to have endurance ratios of 0.4 to 0.45. Fine grained alpha-beta structures or spucturcs produced by water quenching or quenching and aging can be expected to have higher endurance ratios (e.g., between 0.55 and 0.62). However, this trend does not appear to hold true for the notched condition as evidenced by the scatter present in the lower band. The notched endurance ratios variedbetween0.17 and0.3.

ultimate tensile strength, M P ~

80 100 120 140 180 180 #lo Ultimate tensile strength, W

T16AMV: Variation In RT endurance ratio. 6.35 mm (0.25 in.) specimens cut from as-rolled bar, solution treated at indicated temperatures, and cooled at various rates (fumace, air, water quench). Rotating-beam fatigue at 8ooo rpm. Fa- tigue limits at lo7 cycles determined by highest stress ampitude at which three specimens ran lo7 cycles without failure. Source: L.J, Bartlo, Effect of Micro- structure on Fatigue of Tr-6AI-4V Bar, ASTM S"P459.1969

Effect of Residual Stress Surface residual stress is a predominant factor influencing fatigue,

and the residual stress effect is most pronounced in the infinitelife stress rang of the endurancelimit regime (Id cycles or more). Residual stress is even a more potent indicator than surface roughness in this regime, although residual stress and surface roughness are closely related in many instances. This accounts for the traditional correlation between fatigue strength and surface roughness within reasonable ranges of 2.5 to 5 pm (100 to 200 pin., arithmetic average). However, the correlation between fatigue limits and surface roughness may not be as strong as residual a m s ~

Surface residual stress is important, but the effect is not simple because of the combined influences of residual SWSS, cold worked struc- tun and the surface roughness on HCF strength Surface effects on components of HCF are as follows:

surfre C d l Cndr e h t nudeatioa mmutkn s u ~ n n l g b l m ~ Accehtes No effect Cold wal: ReMdr Aceekrar# Reddual comprruiw sms Minaarnoef&* Rerardr

Surface roughness and cold work are often awociated with the procese of inducing residual stress. Because HCF is often largely dominated by fatigue crack nucleation and small crack

T r a n s v e r s e -A- Short tramverse

, 40

2 6 0 1 1 I 30

Effect of Texturn There are two major texture considerations. There is a microstructu-

ral texture in which directly observable microstructural features an aligned on a scale large compand to the size of the individual features. Elongated beta grains in the rolling or forging direction is a typical ex-

There is also a crystallographic texture in which most of the alpha phase grains are aligned such that a unique direction in the hexagonal unit cell of alpha titanium is oriented close to the same direction relative to some physical attribute of the titanium sample, such as the rolling direction for sheet or plate. An example of the ef€m of crystallographic texture is shown (see figure from Zarkadea and Latson), w h m fatigue life in the various test directions in a plate product are large.

Crystallographic texture is seldom reduced by sub-beta m s u s heat treatments, and the texture of the a phase in equiaxed and bi-modal mi- crostructurcs a n be a factor on fatigue limits. In a vacuum environment (see figure), the application of stress in the m v e m direction resulted in higher HCF smngth values as compared to tests in rolling direction. This can be directly correlated to the higher yield stress value observed when the stress is applied perpendicular to the basal planes. The opposite ranking was observed when the tests were performed in laboratory air (see figure), which is explained by hydrogen damage on basal planes. If no shear or normal stresses are acting on the basal planes (tests in rolling direction), then the highest fatigue strength values are observed.

ample of microstructure texture.

P Y '1 0 A \ 1aPA

Mllilng arid turning Gdnding

Non-tradltlonel

-1ooo-Bco600-400-200 0 200 400 6w 800 Peak reslduai Btress, MPa

Ti6AUk Corrrlatlon between endurance h i t and peak residual rtrrsg S o w : W.P. Koster, Effect of Residual Shcss on Fatigue of Shrctuml Alloys, Pracrical Appk'catwns of Residual Stress Technology (Clayton Rudd, Ed.), ASM International. 1991

growth to an observable size, applications of general rules of thumbregatdinsresidualstresseemustbeexsrcisedwithm.

278 I Titanlum Alloy Fatlgue Data

10' 10' 10' 1 0' 1 08 c y o h b mure

w I n u v I

Effect ot Surface Treatment

Shot peening and surface finish intaact in a complex way to influence HCF. Starting with ao undisturbed electropoliabed surface of a fine lamellar microstructure, shot peening will enhance mm-temperature fatigue Wen@ whereas additional elecwpolishing adds to this en-

20q I 10' 10' 1 0' 10' 1 06

Cycles to failure

hancement But, StTe8S relief of the shot wed Specimens reduces fatigue strength to levels below the baseheelectropolishcd samples. Add- ing an electropolish to the s- relieved samples restores most of the benefit. Tests at 500 OC (see two-part f i p , Gray ct d.) indicate that the effeu of shot peening is negative without restoration of the original dec- tropolished surface. Similar effects are seen with h e , equiaxed, micro- s t r u m (see figure, Wagner cr 4.

I

...

-40

200 130 10' 10' 1 0' 10' 1 08

Cycles to failure

0)

'N4AMV: Mect d shot peening and electmlytk pobisbhg. At (a) 20 "C (68 "0 and (b) 500 "C (930 "€9. EF', electrolytically polished; SP. shot peened; SR, s m relieved. MateriabTest m e t e r s : Alloy with a fine lamellar @quenched) miaostructure was machined into blanks 7 x 7 mm (0.28 x 0.28 in.), annealed at 800 "C (1470 O F ) for 1 h and quenched, then heat treated at 600 "C (1110 O F ) for 24 b. Specimens were electrolytically polished to remove a layer about 100 prn thick Shot peening was performed using an Almen intensity of I = 0.28 A (mu). Fatigue tests were performed on smooth hourglass-shaped specimens in rotaring-beam loading (R

200- C: B + l h500°C m

* D: C + 20 prn surface removal - 20

ol 0 1 o4 lo5 1 os 10' 1 od

E B + 20 pm surface removal -

Cycles to failure

TidAI4V: Meet ofshot peening on FatQpe strength. Ep, electrolytically polished. MateriaVrest Parameters: Test material hada fine equiaxedmiaobbucture and a yieldsmngthof IlOOMPa(160ksi). Shotpe#lingwasperformedwithS230steelballs(O.bmmdiam)~anAlmenia~sityof 15Amm1100.Fatiguetesthgwasdone on hourglass-shaped specimens with 3.8-mm (0.15-in.) gage diameter in ah on a rotating-benrn apparatus (R = -1, f = 50 Hz). Source: L. Wagner r r d , Influence of Sulface Treatment on Fatigue Strength of 'R-6AI-4V," in 7itataium Science und Technology, D c u ~ h e Oesellschaft fiir Metallkunds e.V., 1985, p 2147

Fretting Fatigue Titanium has notoriously poor wear resistance when there is

sliding contact with itself and other materials. The resultant frening has a strong effect on fatigue strengths and limits.

l'i4AMV: Fnttlng fatigue In rhot-peened and coated conditions

W w r p c c i m a n

surhrrbrnhteat MR, M h kd M h bi None (88 rcceivcd) 35 220 32 220 32 sboc peened 35 270 39 2Ao 35 Shat pened + CuNi-Io 35 320 46 245 36 N W 140 215 31 190 28

Cyclic teMue load on 5stting pad, Source: %tirig Fatigue in High Temperabm Oxidihg 0 8 ~ 1 , " D. Taylor, in M t h g Fatigue, R. Waterhouee, Ed., Applled 8dhnce PuWhem, Ltd., London, lW1, p 177

Norms1 FmfflnpfatkPCstrenptb3x 1O'Cyda F U R 200C 4aoT

tlBA14V: F W n g fatigue at room tsmpemture and 350 "C (660 O F ) for alby In polished and 8 h o t ~ n e d condltlonr

Fatigue stmneth ~lki 10' ~ y e k r peroca(tdUtth0fbuir Tbrnmnturs Uabtted F* mom-trmuemtwepmge rtks

t d m e n t oc O F MPa luf MPS hl Unfetted Fretted SPrhMl

Plain polwled 20 68 6.50 95 140 20 0 78 Plain polished 350 6M) 5Bo 84 140 20 11 78 Shot-wned A h P A7 20 68 600 a7 340 49 7 48 Sh~t-mmd A h A7 350 660 540 78 310 45 17 52

Cyclic~mileloadonhttingpad, 93MPafreUingetrew. Source:LPrettingFatiguehHighTemperatute ~~r,"D.~lor,iaRcftingFotiguc,R~~ouee, Ed., Applied Wence Publiehen, La, Landon, 1981, p 177

280 I Titenlum Alloy Fatigue Data

1200

There are indications that the Ti-6A1-4V alloy exhibits an anomalous mean stress dependence of HCF strength if the material was forged in the (a + p) phase field in contrast to a normal mean stress dependence if the material was j3 forged or heat treated (Ref 1-3). The results of an investigation on a fine lamellar smcture and a bi-modal structure with a pronounced mixed BIT type of texture tested in RD and TD are shown (see figure, Influence of mean stress). It can be seen that the fine lamellar and the bi-modal structure tested in RD exhibited a normal mean stress dependence of HCF strength whereas the bi-modal structure tested in TD showed the anomalous mean stress dependence, Lee, much lower fatigue saength values with increasing mean stress. No reasonable expla- nation for this effect is given.

Smooth speclmene R=O.l,labair

n-wJv 1200

Air

References

1. RK. Steele and A.J. McEvily,Eng. Fmctwe Mech., 8 (19761, p 31.

2. J. Broichhausen and H. van Kann, OTitanium Science and Technology,," Plenum Press (19731,1785.

3. A Atrens, M, Milller, H. Meyer, G. Faber, and M.O. Speidel, "Corrosion Fatigue of Steam Turbine Blade Material," Per- gamon Press (19831, p 4-60,

I

400 ' \' - - _ _ . I

lo3 10' 10' 10' 10' 10' Cycles to failure (axial ked)

0 2 0 0 4 0 0 B b b 8 0 0 1 o o o Mean stress, MPa

TMAI-4V: Knfluence of mean stress 011 HCFstreagtb (107cycl~). Source: G. Ultjering and A. Gyskr, l h i u r n Science and Technology. MI 4, Deutsche Oe- sellschaft fllr Metallkunde e,V., 1985, p 2072

Hot roflirg temperature, OF 1400 1500 1800 1700 1800 la00

f

,$ i 6

a z

750 850 850 1050 Hot rolllng temperature, 'C

Ti-6AI4k Fatigue of investment costing# after treabnests. ABST, a-p solution tnatment; BST, p solution treatment; BUS, broken.up structure; CST, c w - stitutional solutiontreatment;GTEC,Garretttrea~entIlongtime, low-temperature anneal); HTH, high-tempemum hyhgenation, M h a m s t param-: 5-Hzhiangular wave form. Source: D. Eylonand R, Boyer,'~tanium Alloy Net- Shape Technologies," in Pmc. Int. Con5 77tanium and Aluminum, Paris, Feb 1990

TldAI-QV: Elpeft OPrOUhg temperature on ACFstreogth. MateriaVkt Pa- rameters: Material was 22 mm (0.865 in) in diameter and was produced by 65% hot rolling a( indicated temperatuns, followed by annealing at 700 OC (13oO "p) for 1 h, fumace C d e d to 5M3 "c (930 "m, held fW 12 h, and air Cooled.


10'

b O 6

d

-I PO6 B

10'

mttreatmmt 925 'C (1700 OW4 Wool pt 50 oclh (9l 'Fh)t0760 "C (1400 'WAC 955 OC (1750 O W 1 WAC+ 700 Y (1300"FyZ WAC 870 'c (laOO'Fy2 MAC +700 T (13OoDFY2 WAC 700 "C (1W 'm WAC 1040 OC (1900 opy30mlpIwQ + 700 'c (1300 "FyZ WAC 955°C(17500Fylh/wQ+595'C(1100'F)/4hIAC 955 "c (17n0Pyl WQ + 595 T (1100 DFy24WAC

I I I I I

0 AC, textured plate FC,terturedplate

0 AC, cornentionally p r w m e d plate 8 FC, oonventknally proceesed plate

s m - -. - - - - - \

0 n 0 \

0

0

0 8 ax, strew 345 MPa

Lab alr, /?= 0.05 4 = 2.53, f = 30 HZ

Annealing High-cycle fatigue strength is lowered during annealing due to the

coarsening of grain sizes. During a-p annealing, for example, a longer d n g time decreases HCF strength because of the increase in the grain size of equiaxed a Annealing above the B transus reduces fatigue strength still funher,

-4-h a n M -0 -24 anneal

1 o4 los 1 06 10' Fatigue lib, cycles

Ti-6MV: E € ? e c t d a n n e a l l n g U m e . M a ~ t Parameten: Exrmsionshad acomposition(wt4b)of 6.7Al,0.01 C,O.l8 Fe, O.OW4H,O.013N,O.l640,Md 4.1 N. Mill-annealed extrusions as 76-mm (3-in.) dim cylinders were annealed at 925 OC (1700 'p) for times indicated, followed by slow cooling It SO (90 oF/h). Source: I. Weisset ol., Recovery, Recrys ta l l i~+~~ , andMechar~ical Prop ertiesofTl-6AI-4VAlloy, in P m . 8th lnt. Cod StrengthqfMetalsandAUoys, H. McQueen etal.. Ed., Pergamon Ress, 1985, p 1073

TI-6AISV / 283

0.025 Effect of Cooling

gion or from above the /3 transus. Fast cooling leads to the martensitic

without further aging may result in a low HCF strength if the retained p

Fatigue strength is improved by rapid cooling from either the a-P re-

formation of a', which improves fatigue strength. Water quenching

phase is unstable against stress-induced martensitic transformation.

0.02 5 1

ti 0*015 *i 0.01

0.005

0

3

lo2 lo3 lo4 lo6 lob lo7 Cycles to failure

Ti-6Al-4V: Effeet of cooling h m a-P region on HCF strength. MateriaKI'est Parameters: The a-p anneal alloy was annealed at 800 "C (1470 OF) for 3 h, furnace cooled to 600 "C (1 110 OF), and vacuum cooled to room temperature. Source: M.A. ImamandC.M. Gilmore,FatigueandMicrostructuralhopertiesof Quenched'KdAI-4V, Metall. Trans. A, Vol14A, 1983, p 233-240

1 o5 1 06 1 o7 1 00 106 Cycles to failure

Ti-6A14V: Effect of cooling rates Prom B region. HCF comparison for three conditions for general comparison only.

T M A 1 4 V Materlal condltlon for HCF strength (see above flgure)

I I Aged for 214 h at 500 O C 300

1 o4 1 o5 1 08 1 o7 1 00 Cycles to failure

Ti-6Al-4V: Effect of cooling rate ftom solution anneal on aged HCFstmqth. Materiamest Parameters: Rotating-beam fatigue tests were performed on hourglass-shaped specimens with gage diameter of 3.8 mm (0.15 in.), electrolytically polished surface, f = 50 Hz, at mom temperature in the longitudinal direction. See table for alloy condition. Source: R. JalTee et a/., The Effect of Cooling Rate From the Solution Anneal on the Structure and Roperties of 'II-6A1-4V, in 6th World ConJ 7itanium, 1989, p 1501

hf-ya, Primnycz,03% Yield strength Redudbn h t m e n t vol% pm m kd Inarea, $6 965 O U W Q I a g e d 35 8 1035 150 50 965 oUAC/800 'C for 1 MAUaged 35 8 985 143 41 965 '(337 'C per min/soo 'C for 1 MAUaged 45 10 915 141 34 %5 "U1 'C cer min1800 'C for 1 MAUaged I5 12 955 139 38

STA Condition Solution-treated and aged (STA) matdal has good fatigue strength

but not as good as that of the fine equiaxed or p quenched materials. Age hardening results in the strengthening of the p phase by the precipitation

of small a grains and/or the strengthening of the a phase by Ti3Al precipitates. The degree of age hardening depends on the solution-anneal tmperaftlre and cooling rates.

Next Page

TMAI-8V-28n I327

Common Name: TI462 UNS Number: R56620

'KdA1-6V-2Sn was developed at New Ya.. University on a U, Army contract as a higher-scrength version of 'zfdAI-4V. It is a c m - don-resistant, high-strength alloy which o f f a an ultimate tensile strength of 1200 MPa (175 ksi) in the heat treated condition in sizes up to 25 mm (1 in.) diameter. This grade is used in applications requiring high strength-to-weight ratios at temperaturn up to 3 15 "C (600 "P).

Chemistry and Density Ti462 contains atotal of about 1% (Cu + Fe) in approximately equal

proportions, which give it much-improved bat treatability. Its nominal 6% aluminum content stabilizes the alpha phase and incresses the hot workability range by raising the beta transus temperature to approxi- mately945oC(1735oF).Cwlingfromabovethistemperaturewithlittle concurrent or subsequent deformation generally results in inferior ductility. As a neutral stabilizer, the 2% tin strenst&ts both the alpha and beta phases, and in combination with the aluminum, provides better room- and elevated-temperature strength propetties than those of Ti- 6Al4V and other lower-alloy alpha-beta compositions. Beta stabilization is accomplished by ILomiRal additions of 6% vanadium, 0.5% copper, aadO.S% iron. Acting together, these elements permit heattreatment of the alloy to high strength levels by solution treaPnent and aging.

Density. 4.54 g/cm3 (0.164 lb/h3) Alloy Se@eption. Ingot composition must be controlled within

specified limias, and special melting practices, particularly for the final melt, are required to minimize segregation during solidification. Exces- sive macrosegregation results in "be& flecks," which are harder, lem- ductile areas after heat treatment. Detrimental effects of beta flecks have not b a n demonstrated for this alloy.

ExeeedingComposrtionLimiCa.Asforallalpha-betaalloys,excessive amounts of aluminum, oxygen, and nimgen can decrease ductility and hcturc toughness. Excessive amounts of beta stabilizers (molyWe- num and vanadium) affect the stability of the alloy and increase its heat treatability, draefonmaking control ofpropaties more difficult. Exces- sive impurity levels may raise yield strength above m i m u m permitted valuesordecreaseelongationorreductioninareabelowminimvmv~.

Product Forms Ti-662 is produced by all U.S. titanium melters as bar and billet for

forging stock. Plate, sheet, wire, and extrusions are also available.

Product Conditiona/Mlcrostructure In forged sections and plate up to 25 mm (1 in.) thick, solution-

treated-and-aged material has a guaranteed minimum ultimate tensile strengthof 1170MF%(170 ksi).Forfoegedsectionsbetween75aud 100 mm (3 and 4 in.) thick, tbe correspom%ng ultimate tensile strength is 1035 MPa (150 ksi). The response to k t treahnent may vary from beat to heat and the correct aging temperenue is best deaamined by teats on the heat in question. Cooling from above the beta transus with concurrent or subsequent deformation generally results in inferior ductility.

1450 "F) arc applied to produce maximum stability at temperatures up to 450 OC (600 OF). The seengthening response to the precipitation-hardening reaction is dependent on the ability to retain the beta phase during quenching from the solution temperatue, and this alloy is suff iht ly beta stabilized to attain heat treated properties through section thicknesses up to 100 mm (4 in.).

Annealing treatments at tcmperanves of 640 to 790 OC (1200 to

Applications 'K-662 is used in applications requiring high strength at tempera-

tures up to 315 OC (600 "F) in the f o m of sheet, light-gage plate, am- sions, and small forgings. This alloy is used for airframe smctrtres where strength higher than that of Ti-6A14V is required. Usage is genetally limited to secondary structures because the attractiveness of higher smgth efficiency is minimized by lower fracture toughness and fatigue properties. Ti462 is used fot aircraft structural members, centri- fuge parts, arad rocket-engine parts.

Limitations in Use. As is characteristic of other titanium alloys, exposure to stress at elevated temperature proauCes c h a n p in the retained mechanical properties. The stress and temperature limits below which these changes will not occur have not becn established for this alloy. Structural applications should be baeed on a howledge of the low toughness characterizing the higher-strength conditions of this alloy and the limited toughness of welds. Particular attention should be given to the influence of aggressive environments in tbe presence of cracks. Such environments include aqueous solutions of chlorides and possibly certain organic solvents such as methanol.

556.11 0.5 05 O.O15m# O.[)rlma~ 02ma~ 15-25 554.5 CO.lrnaX;Si0.151~1WbdTI

ShStrpAnn M 0.35-1 0.35-1 0.01Zma~ 0 . W m 0.2m 15-25 5-6 CO.O~IIIWOTO.~IIWGOE

Plt Ann 5 6 0.35-1 0.3Sl 0.01Zara~ 0.0Qma~ 0.2ma~ 152.5 5-6 CODSO~~~X:OTO.~IIUX:OE

5-6 0.35-1 0.35-1 0,OlUma~ 0.M04max 02raa~ 1.5-2.5 5 6 C0.05mU;OT0.4ma~;OE

0.1mW;bdTI

0.1rma;baIm

0.lmax;klTI

0.1max;baln

Row BetAPn 54 0.35.1 035-1 aDlUmax 0.04nnuc 0.Zmarr 134.5 5 6 CO.05mff ;~0 .4max;OE

(continued)


oaaray WL3.7174 WL3.7174

w UNB 38.725 UNB 3&725 USA AMS4918F A M S 4936B AMS4936B A M S 493K

AMS4971C A M S 4978B AMS 497ac

AMS4979B m F . 8 3 1 4 u MILp83142A MUT-81556A MILT41556A MILT- Ma T-90461 Ma. T - W MIL T-9w7G MIL T-9047G

Sb Sap plt Bar F g Am Sb Sap Plt BarF5 STA

L7303 L-7303

Sh Sap Plt Bar Ext Ann Sh SapP11 Bar Ext HT

USA ( c o d i d ) SABl467 n662

ShSt~Plt AM Ext Rng Ann Ext Rng STA

3erFg W~rRngBil Ann Bar Wir Rg Bil Rng Ann

BeraExt Ann Rng Flsh Wld

B = F g m ? h

F % h Frgm bt Bar Shp Ann Kxt Barshp STA Sh Sap Plt Ann ShSapPltST ShSapPltSTA Bar Bil Ann Bar Bil STA

5-6

5-6 5-6

5-6 5-6

5.6 5-6 5-6 5-6

5-6 5.6 5 4

5-6 5.6 5-6 5-6 5-6 5.6 5-6 5-6 5-6 5-6

55 (nm)

03.1 0.35-1 O.O125ttt&~ 0 . M ~ 0 . 2 m 15-25 5.6 CO.OJIMX;OTOAW;OE 0.1 max;balTi

0.35-1 0.35-1 0.0125 0.04 0.2 1.5.2.5 5.6 C0.05:OT0.4;brlTl 035-1 0.35-1 0.012s a04 0.2 1.5-2.5 5.6 CO.M;OTO.~;WI

035-1 0.35-1 OP015 0.04 0.2 15-2.5 5-6 COM;OTO.4;YO.OOJ,brlll 03.1 0.35-1 0.015 0.04 0.2 15-25 5 6 CO.OS;OT0.4;Y0.005,bdTi 035-1 0.351 0.015 0.04 0.2 1.5-2.5 5 6 CO.O5;OTO.4;YO.oo5;bdn 0.35.1

0.35- 1 0,35-1 0.35-1

0.35-1 0.35-1 035-1 0.Js.l 0.35-1

0.35-1 0.35-1

0.35-1

0.35- 1 0.35-1 0.35-1

0.35-1

0.35-1 0.35-1

0.35-1 0.35-1 0.35-1 0.35-1 0.35-1 0.35-1 0,3S 1

0.015 man

0.015 0.015

0.015 msx

0.015 0.015 0.0 15 0.015 0.015 0.0 15 0.0 15 0.015 0.0 15 OD15

OM max

0.04 0x14

ommu 0.04 0.04 0.04 0.04 0.04 0.04 0.W 0.04 0.04 0.04

0.2 max

0.2 0.2

02 mu

a 2 0.2 0.2 0.2 0.2 0.2 0,2 0.2 0.2 0.2

15-2.5

1.5-25 1.5-2S 1.5-2.5

15-2.5 1.5-2,5 1.5-2.5 15-25 15-25 15.25 1.5-2.5 15-25 13-25 1.5-2.5

5-6

5.6 5.6 5-6

5 6 5-6 5 6 5.6 5-6 5-6 5.6 5 4 5.6 56

C0.05 max; OT0.4 man; Y

CO.05; mo.4; Y 0.005; bal n C0.05max;UT0.4max;Y

0.005max;OEO.l mu;bdTi

c 0.05; OTOA; Y om, baln

c0.05; 0 ~ 0 . 4 ; ~ aoos:baln aOO5 max;OEO.I msx;bal Ti

C0.05; OT0.3; taln C0.05; OT0.3; bal Ti C0.05:OT0,3;baln C0.05;0T0.3; bal Ti C0.05;0T0.3;balTi C 0.05; 0 T O . B ; bpl ll CO.0S;OT0,3;balTl C 0.05; OT0.3; Y 0.005; bal Ti C0.05:OT0.3;YO.~;balTi

TI.882: Cmmwcbl comporltknr

S#dBf.tba D a b H o n n Al c u R B N 0 so V O t k

Ram uginc m662 ShPltMAM 5-6 0.35-1 0.35-1 0.015 0.04 0.2 1.5-25 5-6 balm UOb uT662 Sh Ph prS QA 5-6 a35-1 0.35-1 0.015 0.04 0.2 15-25 5-6 balm

DeuadrT CondmAIVSnM-2 Plr BarFrgPipAnn 5-6 0,35-1 0.35-1 0.015 0.04 0.2 1.5-25 5 4 C0.05;balTi DeuacheT CondmAlVSn662 PltBarPgPipSTA 5-6 0.35-1 0.35-1 0.015 0.04 a 2 1.5-2.5 S 4 CO.05;bdTi DeuachcT LT33 RgA@ DFUtgChCT LT33 F g h

J E W

Kok KS66-2 PltShAnn 5.6 a35.i 0.35.1 0.0125 OM 0.2 5-6 balm Kok KsM.2 PhShSTA 5-6 035-1 0.35-1 0,0125 0.04 0.2 5-6 balm Sumirano Ti-6A1-6V-2Sn TDho 662AT STA 5-6 0.35-1 OD15 0.04 0.12-0.2 15-25 S6 C0.05,kl'Il USA OREMEr TIM-2 RMI RMI 6AlbV-2Sn Mult Forms Ann 5 6 0.35-1 035-1 a01254.015 0.04 a 2 1.5-2.5 5 6 C0.08,belTi

1.5-2.5 5-6 CO.W;bdTl RMI RMI 6AlbV-2S0 M ~ l t F a STA 5.6 035-1 035-1 0.0125-0.015 0.04 0.2 lIma T1MPTAL64-2 Am 5-6 035-1 0.015 0.05maX 0 . 2 ~ 1.5-2.5 5-6 C0.05m;balTi Tlmt "METALb-6-2STA BilBprPltShStrSTA 5-6 0.35-1 035.1 0.015 0.04 a 2 1.5-2.5 M C0.05;bdn

5-6 0.35-1 0.35-1 0.015 0.04 0.2 1.5-2.5 5.6 C0.05;balTl 5-6 0.35-1 0.35-1 0.015 ox)4 a 2 1.5-2.5 5-6 CO.05;balTi

QklOlevahleauemlrimllma.

Alloy 'K-662 is normally processed in the a + two-phase field, resulting in primary equhxed a and some @. For example, m a l i n g treat- men& (-760 "C M 1400 OF) moderately low in the two-phase a + p field a A a normal a + p processing result in ~ ~ C T O S ~ ~ ~ C N R S with a high vol-

ume percentage of primary a with stabilized @ at the cquiaxed a grain bounddes. If the processing involves less exposure time or less working in the a + @ region and is subsequently annealed at appmximately 760 OC (1400 OF), the primary a grains appear more elongated, and the

TIBAWV-2Sn I329

volume percentage is high. Both sb'uctllres develop acceptable mechani- calproperties.

TOalY transformed S h ~ t u m often COnsidered u m t a b l e , although acicularproducts do have advantages. Annealing temperatures and cooling rates detennine the presence and the coarseness of secondary a (transformed p). For solution treatments up to 825 "C (15 15 OF), p is sufficiently enriched with vanadium to prevent decomposition into martensitic (1 At temperatures above 900 OC (1650 "p), p decomposes

completely to martensitic a. Between these two -m, partial transformation of p o c m (see the isothermal TIT diagram after quenching from 850 "C or 1560 OF). From above the p transus, the Q temperature is about 420 O C (790 OF).

Crystai Structure Beta'kanwur: 945 f 10 O C (1733 f20T) to955 f5 OC (l750f 10°F)

Transformation Products

5 1 5 3 0 1 5 1 6 3 0 1 2 3 4 5

l6W

// B

---y

10-1 1 10 102 lo3 10' Time, min

Ti462: The-temperattlre transpOnnations from 850 OC (1560 OF). Dila- tometric tests indicated h& temperature of 640 "C (1 185 "p), and X-ray measurements indicated that a' martensite f d when isothermal hol& were stopped by quenching before line A. Beyond line B, p is sufficiently enriched with vanadium to prevent martensitic transformation. Memurements indicated the disap- pearance of 'K3AI(y) beyond line C. 25 nun (1 in.) diam specimens solution treated at 850 "C (I560 "p) for 1 h. Composition (wt%): 5.5 V, 5.65 Al, 2.35 Sn, 0.5 Cu, 0.62 Fe. Source: B. Hocheid etal,, Isothermal h f o n n a t i o n of 'KdAI- 6V-2Sn Alloy After Reheating in the a-8 Range, ntanium Science and Technol- ogy,R.I. JaffeeandHM Burte,Ed.,TMS-AWE, 1973,p 1609-1619

TI-662: Isothermal transformation diagram. Quenched from field to temperature indicated. Source: 7'itanium Alloy Handbook, MCIC-HB-M, Bartelle Columbus Leboratoris, 1972

L o w t + High Solution treatment temperature

Ti-662: WPse transformation diagram. Source: Y. Murakami et al., Phase Transformation and Heat Reatment in 'K Alloys, ntaniurn Science and Technol- ogy,G.LUtjering,U.Zwiclru,andW. Bunk,Ed.,Deu~heGesellschaftfllrMet- allkunde, Germany, 1985, p 1405

330 / Titanium Alloy Fatigue Data

c R f , 0% mean straln 0 FIT, 1.0% mean * 315 'C (600 OF) , 0% A 316 'C (6W OF), 1.096

0.11 . ......., , ......., . ......., . ......., , . . J 1 0" 1 10 lo2 ro3 10'

Cycles

Ti-: strpin cycling for annealed bar. Specimens were 25 nun (1 in.) dim bar vacwm annealed at 705 T (13OO OF), 2 h, FC. S o w : Aempace Simtural Metals Hondbwk, W 4 , Code 3715, Battelle Columbus Labwatories 1975

Number of cydes

Ti-662: Low-cycleaxlalhtipaSlcckannealed2 hat7000C(1300"F)andfur- nacecoolcd. Source: MetaLrHandbook,~l3,W1ed,Amai~Socie~fforMet- als, 1978

w. Axbl fatlgua rttwrgth of extrurkncl (R 0.1)

TI-: RT axial fatbue mtrenm of anneakd date IR= 0.1 1

332 / Manium Alloy Fatigue Data

1w Mnlw Rm0.l AmO.E2

1

I 4-4.0 ii Tim: RT ulal fatigac strength of h- Smooth and notched fatigue smgth at room tempefahlre for u t fl and for p pawssed forging. Beta forging involved bsta block forging followed by u- p finish forging. Heat maanent8 were as follows: maled at 705 to 760 "C (1300 to 1400 OF), 2 ti, AC; solution treated and aged at 855 OC (1575 "p), 1 h WQ t 565 "C (1050 "p), 4 h, AC. Sounx: Aerospace StructrrmlMctclls Handbook, W 4 , Cock 3715, Battelle Co- lumbus krbararoriea 1975

t -ti0 3 1 0' lo6 1 0' 10'

Number of cyob

Tid62:Typlul~istlguertrrngtb.Source:Metals Handtrodt,W3,9thed., American Society forMetaL, 1978

Minimum stress, MPa

-140 -120 .loo .80 40 40 -20 0 20 40 60 80 loo 120 140 160 180 a00 Yinirmm stress, ksi

Tl.662: BT anmoth axid htlgue dmiU annealed plate. Source: Acmspace Shrctuml Metals Handbook, MI 4, Code 3715, Battelk Columbus Laboratories, 1975

Mlnimum stress, MPa

I I I I 1 I 6 1

-140 -120 -100 80 do 40 -20 0 20 40 60 80 lC6 120 140 160 180 M t n i w m m k S l

'Lld62: RTnotched prlpl fatigue OCmU maded plate. Source: Acmspuce Stmctuml Meralr Hmrdbook, W 4. codb 3715, BmUe Columbps Labontories, 1975

Minimum streg. MPe

334 I THanlum Alloy Fatigue Data

Mtnhum slmss, MPa

ii d i d

1 I

RT Urn= 1w kal

-140 -120 -100 8 0 40 40 -20 0 20 40 60 80 100 120 140 160 180 200 Minlmum $tress, ksi

Ti-661: BT notched udol fbtipe of STAphte. Source: Aempuce Structural Mectals Handbook, MI 4, Code 3715, Banelle Columbus Laboratories, 1975

1 0 q . . . . . . . . I . . . . . . . . I 1 10 100

AK, Win.

"-662: Crack growtb rates for annealed plate. 13 mm (0.5 in.) mill annealed plate was tested at room temperahue in air at 50 to 70% relative humidity. S m e : Aempace Srruciuml Met& Handbook, Vol4, Code 3715, Battelle Columbus Laboratories, 1975

I Millanaral 1095 159 2 Mill- 1124 163

4 925 oC( 1 7 W F ) t 760T ( 1400DF) 1041 151 5 915 oC(1675 OF), WQ,59S "C (1100 OF) 1193 173

3 IOIO'C (1850 "P) in vacuum 965 140

10 R = 0.1 and 0.8

t l o - l t . . . . . . . . I . . . . . . . ,

1 10 AY kddhl.

100

TI-662: Average crock growth rate& Fatigue cnrk growth ratcs at room tcm- perahue, tested in Laboratory air at 50 to 70% relative humidity. See table for treatments and yield sirengths. Source: A m s p a c e Strueturn1 Metals Handbook, Vol4, Code 3715, Battelle Columbus Laboratories. 1975

TI-SAIBV-2Sn 1336

i o j . . . . . . . . , . . , . . . . J 1 10 105

AK, kaldin.

Ti662: Crack growth of fl annealed plate. 13 mm (0.5 in.) p annealed plate was tested at coom temperature in air and 3,5% NaCI. Source: Amspace Stmc- rumlMetals Hondbwk,Vol4,Code3715,BamlleColumbusLaboratorieg 1975

10 R = 0.1

10 lap AK, kshh

'lY1662: Crack gmwth In aimdated boay environmglts. h e a l e d sheet at room temperature. Tensik yield strength, 986 MF% (143 ksi). Source: Aerospace StnrcrmdMerols Handbook, M14, Code 3715, Battclle Columbus Laboratories, 1975

ASTM E98972CT Bete~2Snun(lin.) (111.3

40 10"

a 10 20 30 AK kswln.

'pc662: Crack growth rates at -54 OC for STAspeeimenS. 96 m (3.8 in.) quareforged bar heat treatedat 870 OC (1600°P), 30min. WQ+ 540 "c (loo0 OF), 6 h. Source: Amspace StrrrCtnrolMemlr Handbouk, W 4 , Code 3715, Bat- telle Columbus Laboratories, 1975

10'1 . . . , . . . ., . . . . . . . , 1 10 lo?

AK4 Wln.

Tld62:CrPcLgmvtbrang8atmverdtempcrs~ 13mm(O.Sin.)millan- nealed plate tested at -62 to 82 OC (-80 to 180 O F ) . Source: Aerospace Smctuml Mefa& Handbook W 4 , Code 3715, Battcllc Columbus Laboratories, 1975

d i I 470 -1eo 4 0 0 90 180 270

Tmperntufe, 'C

0.018 N% 0.W H2,0.015 C, 059 Fa. AppmxLarrte RT yield amgtb: rL 999 Mpa (145 ki); B, 1241 Mw (18OLd); C, 1172 MPa (170lcli).

T l b M : I m p f t ~ o l p l s t & 2 s m m ( 1 i & ) p l a t e ~ : ~ Q ,

rres?: RTfmduntoughm,ot~krghg,mdbI lbt

TLfrhgl hdnrm-b (.13 mm i& coed ih m bdJk Dtrlba

9.6 0.38 srDAa92!ioC(17ooop), 1h,wlt~tpd1,76OoC(140(3oF), llqrtrcad 47.1 f 13 42,9t 13 I.-T UXbf3.4 46.1 f3.1 TI,

13 0 s ~lmPcaawrs~(1810°p),rh,agooaml 59bf2.2 543f2.0 TI, 13 050 DuFkxrmrsrl 71.5f2.2 65.1f2.Q TC 13 056 Millmd 38.4f5.7 350*5.2 T-L 15.7 0.62 p d + SroAl980 Dc (1SOaTh 30 mln, &cod, 855 OC (1575 W, 30 55Di19 50.1 * 1.n LT

32 1-25 spAs915 T(1675 T), Ismin, wmcplarh, m T ( l l O O T , 4 b 37.4 f 4,l 34.1A3.8 T-L

I.. 64.4 f 2.9 16 f 2 7 LT %5 9M %5 3.8U ~ A U g 1 O o C ( 1 # K ) ' p ) , # ) m i n , ~ ~ w O o C ( 1 M 1 o T , 6 ~ Pir 33.8 f0.7 M.8 f 0.7 LT

55.8 2.m ... 57Af 7.0 52.3 f6A LT 55.8 220 hflIlm#rl*5400C(100O.F),Zhtlrcod 627 f 2A 57.1 t 2.2 LT 305 12.00 ... 69.0t7.6 62.8 f6.9 LT ... 626 f 4.0 57bf3.7 T-L

AL

~ ~ q ~ 5 6 5 T ( 1 0 5 0 ~ 8 ~ a i r ~ - cool

wy

Boltrcb: J. Wlaglmr,aOmqga Zbkmtaf Dcrign H-,W l,BattaL CbIudma- lses


25mm(lin.)plate;(thnapointkadB=l h a = I in., W = 2 iaxa)

1 1 4 ~ 114mm(4.5x4.5 in.)forging(bwbleedgecraFk B = O 5 in.,?a= 1 ia, W = 3 ia.)@)

a = 0.2 io, W = 0.5 in.Xc) 25 lIUn(1 hJELIplate; (W-poimbend B ~ 0 . 2 5 in.,

75 X 22'8 mm (3 X 9 in.) Fwng (centerrrack B I I in., 2 a = 3 in., W=Qin.)(d)

lSsO°F, 30 min, WQ+90O0F, 4 h,AC

15$0°F30min, WQ+ lOOOT.4 h,AC i550 OF, X)min, WQ + 1100 'F,4 h AC 1550nF,30ndnWQ+1300aF,4h,AC 16% O F , 1 h WQ + 1050nF, 4 h AC

1600 'F, 1 h, WQ t 1050 "F, 4 h, AC

1650T, 1 h, WQ + 1125 OF, 4 L A C ANlealedat 1XOoF,2hAC

1575 OF, 1 h, WQ+ 1XNloF,4h,AC

1289

1261 I193 999

l O n

1234

1179 979

11W) 131qr)

167

183 I73 145 149

179

17 1 142

W e ) 1We)

21

n 34 43 66

33

37 61

We) We)

19

25 31 39 60

30

34 54

We) We)

Ti=6=22=22S

UNS Numbr: Unassigned

Compiled by P. Russo, RMI Titanium Co., and R. Boyer, Boeing

Ti-6-22-22s was developed by RMI l%anium Co., with additional development funded through an Air Force Contract in the early 1970s. The alloy was conceived to provide high strength in heavy sections with good fracture toughness and to retain that strength up to moderate temperatures through the addition of silicon. The lack of any production applications prtcludtd M e r development at that time. In- terest in this alloy for fighter aircraft applications, because of its strength advantage over Ti-6Al-QV and good damage t o l m c e proper-

bilizers, chromium and molybdenum, may result in higher strength than desired.

Product Forms. Ti-6-22-22s has been produced in standard wrought product forms such as sheet, plate, bar, and forgings. Sheet exhibits excellent superplastic forming characteristics.

Product Condition. Ti-6-22-22s can be used in the annealed and heataeatedconditi0ns;solutiontreabnent andagingcanprovidesignifi- cant strengthening. The main emphasis at present, except fix sheet, is on

ties, has been revived. A strong effortis underway to develop ther- momechanicsl processing procedures to optimize the strength, toughness, and crack growth rate properties of Ti-6-22-22S in sheet, plate, and

Some data report a relatively high elastic modulus, which could be imporiant for cutain applications. Sheet can be formed at mmtempera- M and haa excellent superplastic forming characteristics.

Effects of Impurities and Alloying. Exceeding impurity limits may result in decreasing the ductility and fracture toughness below required minimums due to the asswiated increase in strength. As with other a-8 titanium alloys, excessive aluminum, oxygen, and nitrogen can reduce ductility and hcture toughness. High amounts of the fl sta-

forged forms.

a triplex hcat treatment involving a p solution treatment with a control- ledcooling rate followed by an a-P solution r reamnt followed by aging to maximize damage-tolerant properties. Sheet should be used in the a-B processed condition.

Applleations, There arc no production applications for Ti-6-22-22S at this time, but it is bill-of-material for the aft fuselage of the F-22 ATF fighter. The primary interest in this alloy lies in its improved damage tolerance properties with respect to sangth in relation to Ti-6A14V.

SpeciTmtions and Compositions. The only specifications for'K-6- 22-22s to date are those written by Lockheed/Boeing/General Dynam- ics for the ATF fighter. The composition limits am established as follows (except Si content may be reduced):

Comporitbn, w( % M Sn Zr Mo Cr s1 W 0 C N E

Minimum 525 1.75 1.75 1.75 1.75 0.20 I , . ,,, I,. .I. 3 . .

Maximum 6.25 2.23 2.25 225 2.25 0.27 0.15 0.13 0.W 0.03 125 P

selected Refemnces . H.R &ips and J.R. wood, Qmehtion of hpertiee and Microstrudures of Ti.W-2Sn-2Zt.2Mo- Xr-O.25Si Titanium Alloy," Roc . 7th Int. Titanium Conf, San Diego, TMWAIME, June 1992, to be published

R.R. Boyer and A.E. Caddey, T h e Properties ofTi-6AldSn- 2Zr-2Mo-2Cr Sheet," Proc. Int. Titanium Conf,, San Diego, TWMME, June 1992, to be published

n4-22-22s n4AI-2Sn-22~2M~2Cr-0,25Si / 339

RC. B b , "Evaluation of Ti-6Al-25 r-2Cr-2Mo-0.23 Si Sheet," Roc, 7th Int. Titanicun Cod., San Diego, W A D E , June 1992, to be published G.W. Kuhlman et d., "Characbrization of Ti-6-22-22s: A High-Strength Alpha-Beta Titanium Alloy for F'racture Critical Applications,R Proc. 7th Int. Titanium Cod,, $an Diego, TMWAIME, June 1992, to be published %echanical-Roperty Data. Ti-Ml-2Zr25n-2M0-2-20r Al-

Battelle Columbus Laboratories, Apr 1073 AK. Chahbarti et at., TMP Conditions-Mimtructure-

loy Qol~tim Treat4 and A@ Plate," F3361672-C-1280,

Mechanical property RelatiolJBhip in Ti-6-22-22s Alloy,"

Roc. 7thInt.TitaniumConf,SanDiego,~AIME,June 1992, to be published G.W* Kuhlman, Beta ProcemeedTi-6-22-22SAghg Studies, Alma Report, Mar 1992

L.J. Bartlo, H.B. Bomberger, and S.R, Seagle, Deep Har- denable 'pitanium Alloy, AFMLTR73-122, Battelle Co- lumbue Laboratories, May 1973

O.L. Deel, RE. Ruff, and H. Mindlin, "Engineering Data on New Aeroepace Structural Materials," AF'MLW75-97, Battelle Calumbue Laboratolies, June 1975

Phases and Structures Wplex heat treatment results in a coarse lamellar a structure in a

transformed matrix. Cooling rates from the solution treatments must beconmlled withinagiven window to provide desired suengths.The retained p contains a line acicular a precipitate due to aging. Very line, submicron-size silicides have been observed in this alloy.

Sheet can be used in the annealed or solution treated and aged condition. An air cool from the solution treatment temperature provides a&- quate heat treatment mponse. The annealed condition consists basically of equiaxed a with inter&ranular j3 (see figure). Material in the solution treated and aged condition is very similar to that of TidAMV, with equiaxed a in a matrix. With solution treatments below about 850 'C (1560 "Fj, p phase at temperature will be retained upon cooling (for sheet gages with an air cool), which provides a strength minimum in the solution treated condition. Solution treating at temperatures above this results in increased amounts of martensite formation as the temperature is increased and higher strengths.

TI-8-22-22S: Summary of typical physical propdrHe,

96Ok 15 Dc (1760 f 25 OF) Not avrrllabk

4.65 g m 3 (0.164 lblm.3) Not available N- Not auallabk Nat availabls

9,2 X l@PC (5.1 X l@PP,

Elastic Properfies Young% Modulus. The high modulus reported by Battelle (see ta-

ble) has never been explained and has not been duplicated. The F-22 program is now workw with amodulus of 113.8 GPa (16.5 x 106psi).

Poisson's ratio. 0.33

122 x ldMPa(17.7~ Id kri) 115xtdMPa(16.8xldhi) 117x l@hdpa(17.0% l d b i )

0.33

H 46xldMPu(6,7x Idbl) Sirm

W22-128: Variation In Young's modulus

110 123 110 107 99

15.9 17.9 15.9 15.6 14.4

112 122 112 110 1oD

16.2 17.8 16.2 16.0 14.6


Corrosion Stre;nd;lorrosion Cracking. Boeing has reported the stress-com-

sion threshold for this alloy to be about 55 M P a 6 (50 k s i G ) in an aqueous 3.5% NaCl solution. Previous work (Baaelle, Apr 1973) reported a value of 80% of the tensile yield strength.

Because Ti-6-22-22s is an age-hardenable alloy, a range of tensile properties is attainable. The alloy can be heat treated in sections up to 75 to lOOmm(3 to4in.)thick.Tensileproperties willdependonprocessing

history and on the solution treatment and aging temperature (although strength is not very sensitive to aging temperature over a fairly widetem- perature range).

TM-22.225: Typical mechanical proprrtlrr for a+ processed STA products

UHlfMtetensllc~npth Telmueyield8tmlg! h ILeductbn product MPo hi MPa M Ebngation, % ofam, % Shea(a) 1331 193 1193 173 7.5 .I.

m.m 1204 175 1131 164 12.0 35 Bill*@) lz00 174 la89 158 15.0 41

S o m : G.A Bella, RhiI Titanium Co., 8 May 1931. (a) Subtraneus (A- 50 "F) eolution tnatment with 640 "C (loo0 O F ) age, 8 h. (b) Supratraneus and eubtmnsua h a t PI- aging

14-22-22s: Typlcal mechanlcal propetties for p9rocessed STA products

Ultimateten&drmgth TeaPUeykldstmngth Reduetbn product MPa hi MPa hi Ebngatka % oforre% 50mm(2In.)plate 1138 165 1020 148 10 17 100 nnn (4 In.) plate 1103 160 979 142 10 15 150 mm (6 in.) plate 1076 1% 958 139 10 15

SO-: J.R. Wood, RMITitanium Co., 16 Aug 1991. &- 28 'c (50 "F)hr 1 h,AUW'c (lo00 V) age, ah, AC

Ti-6-22-228: Mkal mechanical DroDeftIes for a-B roce erred mlil annealed ~roducts

Ultimstetmdlestmtgth Thileyiddstmgtb Rductbn dPnr% Ebmtion. 8 product MPa lui m hi

shea 1103 160 1034 150 10 . I .

plate 1076 156 1014 147 13 28

So-: OA Bella, RMITitanium Co., 8 May 1931. Mill d 7 3 0 "c (1960 "F), 2 h, AC

Plate and Forgings The F-22 program has established a minimum tensile strength of

1035 MPa (150 ksi), and it is felt that the strength should be controlled within the range of 1070-1137 MPa (155 to 165 ksi) to meet the minimum fracture toughness requirement. This has resulted in a cooling rate

window (see figure). The effect of slower cooling rates is a coarser la- mellara and lower strength. Oxygen content has the expected influence on strength and toughness.

W22-225 Ti.6AI-28fi22~2hb2CrORSSi I341

4 1150. ...... ........... ..... .;.. :..'.... ... . . ............ .................................. 1$ 1 o/:lwi -

Sheet The solution treat temperanae has a very strong effect on the me-

chanical pvputies of Ti4-22-22S (see figures). The yield strength IIlinimumisassoclated with the retention of the maximum amount of p.

The effect of superplastic f d g temperatun is similar to that of solution treat te- arad superplastic fonned parts CBP be aged to higher s h ~ ~ g t h ~ (see section on superplastic formiag).

170

150

1 1 'I J 9 0 0

800 120

1 10 1 op rime to 112 tempemre, mh

0.04 0.08 0.08 0.10 0.12 0.14 OxyQsIl content, %

8 0 0 8 2 0 8 4 0 8 6 0 8 8 0 9 0 0 9 2 0 9 4 0 sdutlar treating tempemre, 'C

Ti422-W. Strength and dwtiUtyvssoInt&m haling tempustun. 1.2 mm (0.050 in.) sheet solution treated 30 min, AC, no aging. Source: R.R. Boyer end A.R Caddey, 'The Roperties of 1I-6Al-2Sn-2&2M+20 Sheet" Roc. 7th InL 1Itanium Conf., San Diego, TMWAIME, Jw 1992, to be published

342 / Titanium Alby Fatigue Data

-180

-160 9

-140 : ! -120

C) (b)

T16.U-uS: E h t dsolutkm tempernlure on tenrilc pmpertieb 1.6 mm (0.063 in.) thick sheet heat treated 85 hdkated. S o w : R.C. Bliae. "Evaluation of 'KbAl- 2Sn-2Zz-2Cr-2Mc&2Si Sheet" Rbc. 7th Int. T k d u r n Conf., San Diego, T M W A W June 1992, to k publisbtd

Aghg temperature, 'F 800 g0Q loo0 1100 1200

1SOat I ' ' " " " I b I 4210

Sdulian treated at 925 "C Sdutbn treateQ el 870 OC

loo0 4m 500 goo "I

A@mg temperelure, OC

T16.2222S: Yield stmngtb VB nghg temperatrm. 1.2 mm (0.050 in.) shwt lwatfxcatedasindicaM.Source: R.R.Boyer~mdA.E.Caddey,"rheProperticsof 'K-6Al-2Sn-ZZt-2M0-2Cr She&" Roc. 7th Int. 'Ktenium Ccmf., Saa Diego, TMSlAJME June 1992, to k published

Ti4-22.228: meot oftempentun on twrlle, compnulw, and ahear propertb Room-temperature ratio of tensile strength and compreaslve and shear strength should be similar tar different heat treatment8 and produet foms.

Rooemm UT msw (room 315 Dc (600 OF) 125ocI#Io~FI PmPedum

1002(1453) 1006(14&0)

799 (1 160) 825 (1 19.7)

958 (139,O) 963 (139.7)

737 (101.0) 749 (108.7)

910(1320) 910(1320)

697(101.2) 717 (104.0)

. . 18.0 19.5 185 21.3

m r e n e . % 17.7 19.7 18.2 21.0

(continued)

332 u=l

los(U9) lll(l6.2)

WlU) 891 (1293)

11s (167) 112(16.3)

... ...

349 333

107 (Ism) 110 (16.0)

rn(ll20) 793 (115.0)

109(15.8) loP(15.8)

.,.

.,. .a. ...

Tompemn, *F ,100 240 am 400 €a dQ0 7w mo

1

i r . ... . . . . .. ..... . . . . , . . . ..,.. , .......... , .... .. ..

T-, P

344 / Titanium Alloy Fatlgus Data

1

4 lW;

10

\ 205 'C (400 'F)

315 'C (6W 'F) 425 "c (800 'F)

om C r m p

-50

a0 24 25 28 !27 28 29 8 31 32

PI T(20 + log I ) x 104

"MU-US: Lprson-Mwer weep curves. LaRon-Miller mep curves at 0.2% dcfOnnation for specimens heat treated at 950 'C (1740 OF, 1 h. AC + 540 'C (loo0 T), 8 h. Source: L.J. Banlo, H.B, Bombrger, and S.R. Seagle, "Deep Har- denable 'KtAnium Alloy," Am-'IR-73-122, Battelle Columbus Laboratories, May 1973

'" i - bo

?--

316 'C (800 OF) 1 1 . . . . . . . . I . . . .-

10" 1 10 lo2 id 10' nme, h

42s 'C (e00 O F )

14 . . . ....., . . . . ...,, . . . . ...., . . . . ...., . . . y. 1 0" 1 10 102 los lo'

Time, h

Tib-22-22s Creep and s t m a rupture of forged billet. Duplex annealed; test direction, long transverse. Source: 0,L. Deel, P.K Ruff, and H. Mindlin, "anpineering Data on New Aerospace Shuctural Materials," APMLTR-75-97. Banelle Columbus Leboratones, June 1975

n4-22-22s nbAb2Sn-2Zr-2M~2CrQ95Si / 345

The axial fatigue data on duplex annealed @A) forged billet given below represent data generated in the early 1970s during initial alloy de-

essed material. There is some doubt about the 38 mm (1.5 in.) plate data. The last two curves are representative of the j3-processed material being studied today. Unnotcb&R - 0.1

T1-6-22-225: Transverse axial taigue of STA piate

velopmenthharacterization and should be representative of a-p proc- lknlpcrlturr mOC 315 OC

RT (4al'F) (600 OFI pa

1 d cycles, pa (ksi) 1158 (168) 1034 (150) 924(1W

Id cycles, m mi) W(1W 703 (102) 620 (90) Id cycles, MPa W) 413 (60) 379 (55) 344 (W lo7 pa W) 289 (42) 255 07 ) 255 07)

799(116) 848(123) 517(75)

1 6 cycl~, ~ p e wi) 930(135) 1 0 7 ~ y c l e s , ~ ~ a o r ~ i ) 517 (75) 51705)

NOtcbed, KI 3.0, R -0.1

Note: 38 mm (1.5 i~.) plate, 9M) O C (1740 O F ) , 1 h, AC + 640 "c (lo00 O F ) for 8 h S o w : %Mechanical-Pmperty Data ofTiSA1-2Sn-2Zr-2&2C~AFblL, Battelle Columbue Laborabrie~, Apr 1975

DA Forged Billet

12%0

1120 . . . RT 160

U n n o t e w tnnswm 280 R m O . l , 2 0 H z

1 o5 10' 1 o5 10' 1 o7 ufetlme, cydes

1 o5 10' 10' lo8 10' ufetime, cycles

'IM2t22S:Unno(chedaxialBSiguedDAfugod billet. Seealso~ccompanying Ti-622-22S:NotchedaxiplfatigueofDAforgedblllet. tables on next page.

ll16-22-225: Unnotched axial fatlgue of DA forged blllet (R= 0.1)

RT 400 O F 600 O F kd CYCkg bi evek kd cvcka 145 52,730 145 6,400 135 (b) 135 37,730 135 lP900 125 15,400

115 303,270 115 47,900 105 218300 105 392,790 I05 212,400 95 836600 95 429580 95 1,277,700 95 1,91~loo 85 4527,700 85 10,130,900(a) 75 9,789,300 75 1268,600 70 13,808,600(a) 65 10,003Joo(a)

125 159,300 125 15,800 115 14,700

(a) Did not fpil (b) Failed on loading. Source: O.L. Deel, PI. Ruff, and H. W i n , " E n g h w h g Data on New Aeroepace 8tnrctural Mat8ria4"AFMLTR76-97, BaWe columbue Laborabriea, June 1976

348 I Titanfum Alloy Fatigue Data

TI922.228: NOtChd a%&l fOHgUe Of DA bllbt (RI 0.1 I Kt I 3.0)

RT 400 O F 600 OF w cyckr ksl C Y C h kd cyekr 95 3,600 85 3,700 83 29ao 85 8,m 75 6,850 15 4 m 15 11,400 65 14,700 65 87600 65 23,400 55 wm 55 urn 55 89,100 475 141,200 50 194,m 50 89,900 45 417,400 47.5 527,800 45 153,200 40 237,000 45 10#4,9oO(a) 40 5,069.900 35 17,270,800(s) 3s 11,645,Wa)

(a) Did not fail. Source: O.L. Deal, RE. RUB, and K Mkrdlln, %ughm&g Data on New Aemapaee Structural Materidm," AFhfL-"RP76-97, Batblle cohunbue Labtoliee, June 1976

STA Plate

1 ~ 1 1 8 0

560-

id lo' 1 0' 1 0' 10' Metime, cyelee

Tid-22-225: Fatigue kbavior dunnotched STA plate. 38 mm (1 -5 in.) thick plate heat tmted at 950 O C (1740 OF), 1 h. AC + 540 "C (1oM) OF), 8 h, AC; test direction, transverse; R = 0.1. Source: "Mechanical Property Data: Ti-6AI-22~ 2Sn-2Mo-2Cr Alloy SoludonTbatedaod AgedPlate,"F33615-72C-1280. Bat- telle Columbus hl?oratories, Apr 1973

Beta-Processed Material

550 I 0 a&- 0 0 - 0

I - 1 m m

1 0' 10' Id 10' 10' Cycles to fallurn

"i-6-22-225: Smooth hlgh-cyde PPtigue. Close-die forgings; processed as n o # d R = O . l ; K t = 1.0,30Hz.Source:O.W.Kuhlmaneral.,'~Charaeterization off1-6-22-22S: AHigh-Strength Alpha-Betallmiurn Alloy formaclure Critical Applicahns," Roc. 7th Int. ntanium Conf., san Diego, TMSIAIME, June 1992, tobe published

-120

150 , , , , ...,, , , , , , , , , ~ , , , , . , . , , , , , , , - lo3 lo' 1 o5 1 oB 1 0'

Libtime, cycle8

TI-6-22-22s: Fatigue of notched STA plate. 38 nun (1.5 in.) hick plate heat treated at 9SO "C (1740 OF), 1 h, AC + 540 "C (loo0 OF), 8 h, AC; twt direction, transverse; R = 0.1; Kt = 3.0. Source: "Mechanical Property Data: TidAl-2Zr- 2Sn-2Mo-2Cr Alloy Solution bated and Aged Plate." F33615-72-CI280. Bat- telle Columbus Laboratories, Apr 1973

Ti-6-22-22 beta heat treated Ti*-22-22 Ma forged

1 a a loa 10' 10' 10' 10' 1d

Cydes to fallure

Ti-6-22-22s: Notched hlgh-cycle fatigue. Close-die forgings; pronssed as noted.R=O.l.Kt=3.0,30Hz.Source: " C ~ t e r i z a t i o n o ~ - ~ 2 2 - 2 2 S : A H i g h - Strength Alpha-Beta lltaaium Alloy for Fracture Critical Applications," Roc. 7th lot, 'Itmiurn Cmf., Saa Diego, TMSIAIME, June 1992, to be published

1-6-22-22s Ti-6AI-2Sn-2Zr-2Mo-2CrQ95SI I 347

The first figures represent early data on a-p processed STA plate, whereas the remaining f i g a s for p - p m a d material. The crack propagation rates of the latter rn similar to that of kannealed ELI n- 6A1-4V. It is readily apparent that the rapid cooling rates, which refine

the transformed p structure, detract from fatiguecrack growth resistance. The effect of thermomechanical processing is also illustrated. Ba- sically, the data indicate that the lamellar a-P structure, i.e., P-pmessed

Provides the crack Wwth rates*

Billet

R = 0.1 , 10 cycle&

10 1 o2 Strewintensity factor range,ksiJin.

Ti-6-22-22S: Fatigue crpck growth rate in forged. 150 mm (6 in.) d i m billet; 950°C(17400F), 1 h, waterquenched+54ooC(I000'F), 8h.AC;testdirectio~ LS; yieldstrength. 1083 MPa(157 ksi); R 10.044; 25 Hz. Source.L.J.B&,H.B. Bomberger, and S.R. Seagle, "Deep Hardenable 'Ktanium Alloy," AFMLTR-73-122, Baaelle Columbus Laboraton 'es, May 1973

STA Piate

R=O.lOO Frequency = 1 .OO HZ No. of smlmens = 1

R=0.100 =2O.W HZ

No. of specimens = 1 No. of data points = 74

1 10 1 o2 1 os Stress-intensity factor range, ksiJin.

Ti422-22S: Fatigue crocking in 3.5% NaCl of STA plate. 16 mm (5/8 in.) thick plate; test direction, longitudinal transverse; environment, 20 'C (70 OF), 3.5% NaCI; yield strength. 1083 MPa (157 ksi); specimen, 3.8 mm (0.15 in.) thick. Source: h g e Tolemnr Design Hadbook, part 2, Metals and Caamic Infor- mation Center, Baaelle Columbus Laboratories, Jan 1975

0 Frequency = 20.00 Hz No. of data point8 = 73 No. of specimens = 1

Frequency = 1 .W Hr No. oi specimens = 1 No. of data points = 101

L

@ 104: , , , , , , , , , , , , , , , , . , , , , , , ,.

1 0" 1 10 id Stress-Intensity factor range, W i n .

Ti-6-22-22s: Fatigue cracking in air of STAplate. 16m(%8in.)U1ickpW,m direction, longitudinal m v e r s e ; environment 20 OC (70 OF), 95% relative humidity; yield men& 1083 MPa( 157 ksi); specimeh 3.8 m(0.15 in.) thick. Source: h g e Tolemnr Design Hand&&, Pat 2, Metals and Caamic InfomWion Center, Battek Columbus Laboraton 'es Jan 1975

348 I Tltanium Alloy Fatigue Data

8

a I a

RsO.1W Fmqww = 1 .OO H t No. ol data points = 95 No. d specimne = 1

Frequency I 1 .W Ht No. ot Bpsclmene = 1

Rr0.100

No. of dete pints = 132 Li 1041 , , :. , , , . , , I , , , ,,,, , , , , . . . , , , , , , ,,A

1 10 14 1 o3 1 0' Strass-intsnstty factor range, ksiJin.

Ti-6-22-225: Fatigue crnckhg in 35% NaCl of STA plate. 16 mm (5/8 in.) thick plate; test direction, longitudinal tramverse; environment, 20 Dc (70 OF), 3.5% NaCI: yield strength, 1083 MPa (157 ksi); specimen, 3.8 mm (0.15 in.) thick. Sourm: T d c m Design H a n a b k Aut 2 Metab andceranric Infor- metiOncenteC.BemelleCOlumbusLaborstaries,Jan 1975

Beta-Processed Condition

n&22.22 beta heat treated (tan ccd) n-6.22a beta heat tnated(oil quench)

10

Ti4-22-22S: Fatigue crack grantb rate of lorginp Forged pancakes proc- essedasindicated.R..0.1,20Hz,labair'KdAl-4VELI, R~0.01, Source: G.W, Kuhlman ct aL, "Characterization of 'K-6-22-229: A HighStnngth Alpha-Beta ?Itanium Alloy for Fracuue Critical Applications,"Proc. 7th Int. TZtaaiumConf,, San Diego, TMSIAIME, June 1992, to be published

10'' I 10 lop Stress-intensky factor range, Wgn.

Ti-6-22-22s: F O # p CnCLIng in 33% NaCl OCSTA plate. 16 mm (5B in.) thick plate; test direction, longitudinal tramverse; environment, 20 OC (70 OF), 3.5% NaCl; yield seength. 1083 MPa (157 hi ) ; specimen, 3.8 mm (0.15 in.)

m a t i o n ~ , B a w e c o ~ ~ ,Jan 1975 thick h U W m l b k m t & S @ t - h l t 2 , h k @ k C m d ~ I n f o r .

lod 10 loo

Stresa-lntensity range, MPa.lrn

ll-6-22-225: Fatigue crack mth rate cornparkon. R = 0.01,lO Hq lab air. Source: A.K. Chakrabarti, R. Pishko, VM. Sample, and G.W. Kuhlman, ' m P Conditions-Mimiructure-Mwhanical Property Relation in 'IEd-22-22S Al- loy,"Roc. 7th Lnt~~taniumConf.,SaaDiego,TMS/AIME, June 1992,tobepub lished

10.~1 . , , . . , . . J 10 1 on

Stress-lntensity range, MPaJm

TM-22-215: FatQue creck pwth rate w applied latensity of forp

Source: A.K. Chakrabarti, R. Pishko, V.M. Sample, end 0.W. Kuhlman, "T?vfP Conditiom-Microstiuct-Mechanical Roperty Relation in 'K-6-22-22S Al- loy,"Roc.7mInt.ataniwnConf.,SanDiego,TMS/ATME, J ~ n e 1992,tobep~b- ushsd

lags. Forged pancabs, triplex beta heat treated with varying cooling rates.

lo4: BetaSTA

A Duplexannealed 4 , 0

A

Bc+b4 4m O

1 0"

lo.T/ , , , , , , , ,

0

0 1 0 2 0 ~ 4 0 5 0 6 0 7 0 8 0 9 0 AK MPaJm

Ti-6-22-2ts: Fatigue vock growth rate comparison in 3 3 % N t C t Speci- menswereaa-f3mlled 14mm(0.58 in,)plsreinthneconditions:(l)Bwaealsdat 35 "c (65 79 above the f3 transus, 1 h, AC; (2) B solution treated and aged at35 'C (65 "p, above the @ transus, 1 h, AC t 540 "C (lo00 "p), 8 h; or (3) duplex heat mted by fl anneali+30 'C (50aF)below ths@transus, 1 h, AC+540'C (loo0 "p), 8 h. Specimens were tested in the LT direction, R = 0.1,2 Hz. Source: H.R. phdlp and J.R. Wood "Correlation of Mechanical Ropaties and Microstruc- tures of adA1-2Sn-Z~ZMo-2Cr-0.25Si Tltenium Alloy," Proc. 7th ht. 'Kta- dum Conf.. San Diego, TMS/AIME, JUM 1992, to be pubiished

3SO I Tltanlum Alloy Fatigue Data

% fracture properties ofTi-6-22-ZS , as for other a + p titanium alloys, are quite dependent on strength and microstructure. In general, the p-p-ssed/a-p -ded ~ ~ - p p r o c e s s e d / p conditions produce better toughness than codtions thu result in fine + p micro- smtures. The effects of thennomechanical processing and oxygen content on fracture toughness an shown below. Similar to the results for fatigue c m k propagation rates, the data show that the transformed p

structure provides the maximum fracture toughness. It also illustrates an unexplained drop in fractuR toughness as the aging ternperm is increased. Similar behavior has k e n o b w d for p l a i n - ~ W ~ ~ or mixed mode fracture toughness in sheet, as shown below. It is speculated that this drop in toughness is related to an ordering reaction in the alpha and/or silicide precipitation.

114-22428: Fracture toughnew of sheet

Aging temperolure Ultimate tensile ltrrnLtb RMik YW m t h 'Lbuehnua (K-3 oc 'F M h ksl MPP ksi E h W % MPa&n hd4Ib

480 900 127s 185 1160 168 11.7 165 150 565 1050 1240 180 1170 170 11.2 109 99 675 1254 1140 165 1078 155 10.4 112 102

Note: Tedle pro- are the average of eix values each, snd toughrma valwe are the average6 oftwo h t a each. 1.2 mm (0.05 in.) sheet was solutiontrrated at Boo "C for 90 min, aged 8 h. Source: RR. Boyer and AE. Caddey, T h e Fmpertb ofTiSA1-2Sn-2Zr-2Mo-2Cr Sheet,'' Proc. 7th Int. Tltnnium Cod., Sari Diego, TMWAIMZ, June 1992, to be puwhed

Tl-6-22425: Fracture toughness and Impact toughness

Elongation C-V-ao(eh UItlmatetensik drenath ina5mm(l ln) , imwct toushmg F - m t o t l W (K.)

Dimtion m ki % J h . IW MR4U MJin Longitudinal 1160 168.3 18.0 18.8 13.9 .,. .,. Transvcrre 1163 168.7 17.7 22.1 163 .,. ..( L-T ,,. ... ... ... ... 96 aa T- L .I, 1 1 1 ... ... .,, 102 93

38 mm (16 in.) thick plate, STAcondition. Source: W , Apr 1978

Ti16-12-228: Typlcal fmctun toughness of pprocemod STA products

Ulrislsteteadlemgth Yieldstmuth Reductbn RPaurrtouLhnesa(if'3 Product m kd rn Lrpi E b n e s t h , % ofsw, % M P a h M 4 h SO mm (2 in.) plate 1138 I65 lox) 148 10 17 a5 77

150 mm (6 in.) p k 1076 156 958 139 10 15 98 89 100 mm (4 in.) plate 1103 160 979 147 10 15 89 81

S a m : JR Wood, RMI Titanium Co., 16 Aug 1991

Tl-6-22.228: Fracture toughness of a + p processad STA product8

Ukhte beMtk stmath P d k y i e l d araneth Beductbn Fraetumtouphaars ur,) Produet m lud MPa bi EkaestbeJb of-% hiPdrn kdh 5Omm (2 in.) plate 1207 175 1131 164 12 3s 67 61 1SOm (6 in.) billet 1200 174 1089 158 15 41 6s 72

Source: J.R Wood, RMI Titanium Co., 16 Aug 1991

Strain Hardening The m-values, indicators of the superplasticity of material, h m 790

to 925 'C (14H)to 17Oo 'p) at two strain rates are illustrated.

Ti-3AI-8V-6Cr-4Mo-4Zr (Beta C) Common Name: Beta CTM, 38-04 UNS Number: R M

'K-3Al-SV-6Cr-4W2k (Beta C) is a commcfrcial alloy developed

ll&3A1(13-11-3~, but is easier to melt and shows less segngation. Beta C was developed as an improvement of 13-11-3 which had 801ltc melting problems due to a high chromium content. Due to its significant

mlybde-nnm content, Beta C exhibits supaior resistaace to nducing

tanium alloys. currently, Beta C holds a small amount (much less tban 1%) O f ~ P ~ ~ ~ ~ ~ e ~

by RMI in ths mid-to-lste 1960s. It hes sintilar C- * 'cS toT1-W- acids and Chloride &cb compared to 0th high- strength ti-


Chemistry and Density Baa C is fhnulated by depressing the beta transus with the beta iso-

morpbous elements, molybdenum and vanadium, and the sluggish beta eutectoid element, chromium. It is slightly more beta-stabilized than li- 11.SMo-6ZASSn (Beta 110 and less beta-stabilizedthan lI-13V-llCr- 3AI.

Density, 4.82 g/cm3 (0.174 Ib/in.3)

Product ConditionMicrostructure Beta C is cold rollable and drawable, and is used mainly as bar and

wire material for aircraft springs; it has also been explored as a spring material for automotive applications. It constitutes less than 1% of titanium products. Beta C can be heated to high levels above 1380 MPa, 200 k s i - b y aging between 480 and 595 "C (900 and 1100 "F), Large variations in tensile strength can be obtained by varying tho aging tempera- tureandtime. Aportionof~e~phasetransformstoafinelydispersed alpha during aging. Also, it does not grain-coarsen as rapidly as other

TMAMV6Cr4Yo4Zr (Bets C): SpaclfkaMnr

beta alloys when heat treated or worked at temperatures above the beta transus,

Applications Beta C is used in fasteners, springs, torsion bars, and in foil form for

making cores for sandwich structures. It is also used for tubulars andcas- ings in oil, gas, and geothermal wells.

Use Limitations. Beta C, like other beta titanium alloys, is highly susceptible to hydrogen pickup and rapid hydrogen diffusion during heating, pickling, and chemical milling. However, because of the much higher solubility of hydrogen in the beta phase than in the alpha phase of titanium, this alloy has a higher tolerance for hydrogen than the alpha or alpha-beta alloys.

Beta C can be welded in the solution-treatd condition; however, welding is not recommended after solution treating and aging. Care is necessary in pickling to minimize hydrogen absorption.

UNSR58640 3 6 4 8 4 baln USA AMS 4957 Bar Wlr CD 3 4 53-65 0.3 33-45 003 0.12 75-85 35-45 H0~303;CO.~;OTOA;YO.W5;bel'II AMS 4958 BWRodSTA 34 53-65 0.3 3.545 0.03 0.12 7.5.8.5 354.5 HOM;CO.as;oTO.4;YO.W5;baln M I L T - W W B - 3 ShSQpltSHT 3 4 554.5 0.3 354.5 0.03 0.12 7.5-8.5 3.545 H0.02;C0.05;OTOA;M~ M I L T - W CodeB-3 ShShpPIISTA 3 4 5 , 5 4 5 0.3 35-45 0,03 0.12 7.5-8S 33-45 H0.02;CO.o5:OTOA;balTI MILT-90470 Ti-3AI-8V-604W4ZZ BarBilSTA 3 4 5.545 0.3 3.5-4.5 0.03 0.12 7.5-8.5 3.54.5 H0.02;CO.DS;OTOA;Y0.005;bal~

Ti-3AbBV6Cr-4Mo-4Zr (Beta C): Commercial comporltlonr

S m t h l Destrllrtion M p t b n Al Cr Fe Mo N 0 V Zr Other USA Asm Ti-3A1*8V-6Cr4Zr4MO Bar S ~ r g Pip 34 55-63 3.5-4.5 0 . 0 3 ~ 0.1411~. 7S8.5 3.545 CO.05ma~;bal'Tl olemec n-38-6-44 RMI 3Al-8V-@3-424MO ShPlt BarBil Wire 3-4 5.5-6.5 0.3 35-45 0.03 0.14 7 5 4 . 5 3.54.5 C0.05;bstTi TeldynS % I - T ~ - ~ A I - ~ V - W ~ M O ~ I 3 4 55-65 0.3 33-43 003 0.14 75-85 3.54.5 TImn TIMETAL 3.8644 Xng Bil S U 3 4 5.5-6.5 03 3.5-4.5 0.03 0.14 15-83 3.545 H0.02;CO.O5;balTi

COmDOSMOIh 96

As a solute-rich p alloy, precipitation of a within the solute-lean p regions (p? of Beta C is slow, Prior cold work accelerates the formation of intragranular a and also reduces the extent of grain boundary a. Peak aging 480 oc (900 OF), d smaller quantities of a (in the form of m e precipitates) are found at higher temperatures. 7)pe 2 a occurs during certain aging treatments. Recrystallization occurs after

short times above the fi transus, although p grain growth is not a pmb- lem. The possibility of a second phase responsible for inhibiting grain growth above the B t r a n s ~ s has k n suggested @.A. Wood and R.J. Fa- vor, 77itaniwn Alloys Handbook, MCIC-HB-02, Battclle Columbus ~ b o ~ ~ r i e s ~ 192, Section 1-12, P 72-11,

Ti-3AI4V4Cr4Mo4Zr (Beta C) / 353

MK) 554 600 850 700 Aoiw temperature, "c

Betp C: Emeet Opoplnp tempersLprt. Effect of aging temperature on amount of a phase precipitation in 5 mm (1.25 in.) thick plate solution heat treamd at 925 'C (1700 "Ff) and aged. Source: R . k woad and R.J. Favor, ntanium Alloys Hand- hkMCIGHB-02, BattelleColumbusLaboratories, l9Z, Section 1-12,p72-1

Beta lhmus. 730 "C (1350 OF). The previously published transus temperatun of 795 "C (1460 "F) is too high.

1 ,oo 1.40 1.80 2.20 2.80 fl stabilizer content

B e t s C : ~ t l o n o l e l r t t i c e ~ t e r . V a r i a t i o n o f p i a n i c e ~ e r w i t h B stabilizing alloying element content ( m a t i z e d to unity at zero volume fraction of a). Source: O.H. Isaac and C. Hwuaoad, The Formation o f m 2 a phape in ' K - ~ A I - ~ V - ~ C ~ ~ Z ~ M O , in 7ffmium, Science and Technology. G. LUtjering, U. Zwicker, and W. Bunk, Ed., Deutwhe Geselbcbaft fUr Metalikunde eV. Germany, 1985.p 1608

1250 1360 1460 15.54 1850 1750 Tenslk strength, MPa

Beta C: Ffatigue lb dshat p n e d w k . Shot peening is aaitical parameter and shot pan httnSides of a! kest 0.016 to 0,OI 8 A should be wed. Higher intensities would provide additional improvement in fatigue life, but a higher inoensity all-out could limit the number of shot p i n g sources available due to equipment limitations. ThB effects of cold work and tensile strength on the ayeTagt fatigue life of 10 mm (0.4 in.) diam shorpeensdt00.016 t00.018 A. I k h d a t a p o i n t ~ t h e log avswgcofaix tests. 'II-13V-lCr-3Aldatapoints kluded forcotnparkm. 1034MPa ( I J O k s i ) m a x i m u m ~ , R = O . l , ~ H z S ~ : B e t a ~ u M i u m A l l a y s L r d h 1 9 8 0 5 , R.R. BoyerandH.W.Rosenbag,Ed,TMS/AIME 1984

0 0

.-4t I 1300 1W 1401) 1450 1500

Tenslle strength, MPa

Beta C: Fatigue life OtmrgatalW w h . Conml of grain size is desired, and the Wire should be r%crystallizcd during SOlUdW tnatment. S p e C h m ~ Were 9 mm (0.35 h) dim wiR cold worked 35%. Shot peen hten&yof 0.016 to 0.018 A, 1034 MPa (150 ksi) maximum atresa, R = 0,1,30 Hr Swrcs: Beta nranium Alloys in the 19803, R.R. Boyer and H.W, -berg, Ed., TMWAIME, 1984


1 o4 1 0' 1 oB 10' Lifetime, cycles

Beta C: Arial Wgue at high temperature. Unnotched specimens (R = 0.1) from 150mm(6in.)diamforg~g,815'C(1500°F)for 15min,AC,plusaged 12 hat565 OC(1050'F),AC. Source: Bern i"itaniumA1loys in rhelW's,R.R. Boyer andH.W. Rosenberg,Ed.TMSIAIME, 1984

Beta C: Fatlgw life at hlgh tempcHatutsr

'IQt eondYbn(n) RT Z O S F (mop, 370~(700QF) Fatkw UA, Men (kslh ak

1144 (166.0) 1089(158.0) 1020 (148.0) 855 (124.0) 731 (106.0) 634 (92.0) 6(10 (87-0) 551 (80.0) 372 (54.0)

1 cycles 827 (120.0) 717 (lW,O) 634 (92,O) 303 (44.0) 248 (36.0) 275 (40.0)

"YSb

NmPfi) 10s m 107 cycla

1 6 cycles 1O'cycles 275 (40.0) 207 00.0) 234 (34.0)

(a) Axial fatigue of trsnsveree spacimena f h m 160 mm (6 ia) diam STAforging treated 1Smfnat8160C(lWO°F),AC,pluea~at 16'C(10M)4F)for12h,AC. R = 0.1. (b) 4 = 3.0. Souroe: Beta !&zniurn Alloys in the I$8Ob, KR. Bopr and H.W.Roeenberp, E d . , W A I M E , US4

Fatigue Crack Growth Crack growth rates in the accompanying figures were determined

for Beta C in various conditions (see table). Because Beta C is an attrac- tive alloy for highly corrosive environments such as in sour wells, the effect of aggressive environments on mechanical behavior also is of interest. For the test results presented here (see figures), no noticeable ac- celeration in crack growth rates was found when going from air to a saltwater environment, or when the frequency was reduced. Because the differences in du/dN-AK behavior are insignifmnt, data are presented as single scatterbands.

A slight tendency toward faster growth rates was observed for LO- Simplex and LO-Duplex (see figure below) as opposed to HI-Simplex

-100

370 O C (Too ' F Y

01 , . . . , , .., , , , , ....I . , . . ....I . . , , Id 1 o4 1 0' 1 0'

Ufetlme, cycles

Beta C: Notched strength at high tempuatum Axial fatigue of notched specimens (R = 0.1, Kt = 3.0) from 150 mm (6 in.) diam STA forgings. Source: Beta 'IIraniiun A N q s in the 198OL, R.R. Boyer end H.W. Rosenbeg, Ed.. TMWAIME 1984

and HI-Duplex, presumably as a consequence of the lower ductilities. No effect of the duplex versus the simplex aging treatment was detected. A significant difference, however, was found between aged and unaged material. The value of A& is roughly 3 M P a G ( 2 . 7 hi*) for aged mataial under all testin conditions, as opposed to values of 4 to 5 M P a G ( 3 . 6 to 4.5 ksi& for as-SHT material. Correcting for crack closure me^) brin s the data into accord and reduces to 42 M P a 6 (1.8 hid), suggesting that the difference between as-SHT and aged material may not be present at high R ratios.

Beta C: Material condition In crack growth tests

'Ikasikyields&reneth@J% OR&) UltllllPtetcllrUcrtRqpth A e ~ t trsrtmeat(a) (dzsignatkm) M h bi Mrn ksi 800'C, X)dn,AC(M-SHT800) a95 130 895 1u) 925 'C, 30 ndn, AC(abSHT927) 8so 125 850 125 as.SHI' 800 + 535 'C, (8 h) (LO-simplex) 1225 177 1320 190 ~s-SHT 800 + 425 'C, (4 h) (LO+kX) 1220 176 1300 188 ~SHT927+53OoC(16 h)(?II-Simplex) 1140 165 1220 176 ~-SHT9T7+455T(4 h)+555(16 h)(HI-duple~) 1075 156 llso 171

ReduEtka ekneatbn, % of-%

22 48 25 62 8 15

10 13 12 21 14 23

(a)The grain mires aftar wlution heat treating a t 800 and 925 OC were 45 and 160 pm, respecljveb, The 800 OC SHT did not pully remylrtallixe the -hot worked structure, a n d l e R a ~ t e l y 2 0 v o l . %uarecr)alall~.AlIIIolrtnounrecrystallizedgrainewe~p~~taAsr8HTat925OC,ForbothSHT,the4hrcyclepromoteeaeomewhat more homogeneous a dieh.ibution Source: H.E. Krugmaan and J.K Gregory, Mi- and Crack Propagation in Ti-3Al-SV-6Cr-4M&r, in AdiQ.ostrudum and h p e r t y ReZationehips in lUaniurn Aluminia2.s and Atloye, YW. Kim and RR Bow, Ed., TM8/AIME, lWl, p 651

Ti-3Al-8V-6Cr-4Mo4Zr (Beta C) / 355

10.7

: HI-simplex, alr 10 Hz A HI-simplex, NaCl 10 Hz

'K Uncorrected scamband

1 10 AK, MPaJm

BetaC: Creckgrowth with high-ternperatureST. Source: H.E. Krugmannand J.K. Gregory, Microstructure and Crack Propagation inTi-3A1-8V-6Cr-4Mo-4Zr, in Microstructure and Property Relationships in Tltanium Aluminides and Alloys, Y-W. Kimand R.R. Boyer, Ed., TMWAIME, 1991, p 549-560

LO-slmplex, NaCl 10 Hz Loduplex, air 10 Hz LO-duplex, NaCl10 Hz . LO-dupbx, NaClO.1 Hz

1 10 AK, MPaJm

Beta C: Crack growth with low-temperature ST. Source: H.E. Krugmann and J.K. Gregory, Microstructure and Crack Propagation inTT-3Al-8V-6Cr-4Mo-44Zr, in Microstructure and Pmperty Relationships in Tltanium Aluminides &Alloys, Y-W. Kim and R.R. Boyer, Ed., TMS/AIME, 1991, p 549-560

Beta C: Fracture toughness of bar

Test

785"C(145OoF). 1 h,AC C-R +550°C (1025 OF), 24h,AC C-R

R-L R-L

840°C(15500F), 1 h,AC C-R C-R R-L R-L

Condition direenon

+ 480 *C (900 "F), 24 h, AC

53.7 48.9 55.7 50.7 53.3 48.5 56.7 51.6 55.1 50.1 69.2 63.0 57.6 52.4 55.2 50.2

Note. Specimam were &om 76 mm (3 in.) bar. Source: G. Bella et al., Effects of ProceeeingonMicmetructure and Properties ofTi9A1-8V-6CAM&(Beta C"), in M h t r u c t m a n d Property Relatwnehipe in IlEtanium Aluminidea and AUoye, Y-M. Kim and RR. Boyer, Ed., TMWAIhfE, 1991, p 493-610

as-SHT 800, air 10 Hz as-SHT 800, NaCl 10 Hz ~s-SHT 800, NaClO.1 HZ as-SHT 927, alr 10 Hz

1 O 7 - m

11 as-SHT927,NaCi10re,!@@ as-SHT 927, NaCiO.l Hz

la" 6% t / /

A I I

1 10 AK, MPaJm

Beta C: Crack growth in solution treated condition. Source: H.E. Krugmann and J.K. Gregory, Microstructure and Crack Propagation inTf-3A1-8V-6Cr-4Mo- 42r, in Microstructure and Pmperty Relationships in ntanium Aluminides and Al1oys.Y-W. KimandR.R.Boyer,Ed., 1991.~549-560

Beta C: Fracture toughness of STA billet

Test Fraeture toughness (K,J Ultimate tersile strength lknsileyield strength (2% offset) Reduction E l o ~ , % ofnea,% Treatment direction M P s G hiJi m hi m ksi

Water quench L %.7 88.0 1189 172.5 112.5 163.2 9.5 19.6 T 62 56.4 1188 172.4 1145 166.0 3.0 5.6

Air cool L 89.9 81.8 1208 175.2 1150 166.8 9.2 17.4 T 63.3 57.6 1242 180.2 1184 171.7 3.5 6.6

Note: Specimens were 150 mm (6 in.) billet solution treated 815 "C (1500 OF), 15 min, cooled (WQ,AC), then aged 12 h at 565 "C (1050 OF), AC. Source: RMI CO., reported in Industrial Applicatwnsof lIItaniurn and Zirconium: Fourth Volume, C.S. Young and J.C. Durham, Ed.,ASTM srP917,1986, M, p 155

356 / tltanlurn Alloy Fatigue Data

Beta C: Fracture toughness of billet, forging, and piate

m m w Heal streneth a;, Xb spcdamlbutkn treatment Dimtba Mpn kri W d r n MJin m J a WJIn Bilkt 150 nun (6 h.) d i m IS min 815 T(1500T),AC L l l S l 167 ,.. . I . 9%) 8 W

(midradiusspecimas) + 12h,565°C(1050eF),AC T 1186 172 ... ... 64 58 . I S min, 815 'C(lHx,'R, WQ L 1124 163 ... 1 1 1 97 88

+ 12 h. 565 nC(lOSO°F),AC T 1144 166 1 1 1 1 , - 61 56

8h,510'C(9SOT),AC T 1330 193 ... I , . 55(d We) plus exporcd(d) T . I , ... ... ... 54 49

8 h, 565 OC (lOs0 OF), AC T .,. ... .., . a . 69 63 plus exposedtd) T ... ... .I, ... m 64

8 h, 620 "c (1 150 'F),AC T ... ... ... ... 81 74 plus exposed(d) T . I , ... I . . 80 n

hkrie# Fracturrtauglllm

150 mm (6 in.) (location A n n e W ) + aged: U-)

15Ox 150mm(6x6in.) suriacespecimeas 15 mih815 T(lMO"F),AC (C) l l S l 167 ... .,. M ( e ) SSWe) Center specimem + 12hS65°C(10S00F),AC (C) l lS l 167 (0. .,. n - 7 1 945

(foging center sped mns) + 12 h, 565 T ( 1050 OF), AC L 1158 168 ... . . I SMKe) 53-We)

(mt=SpCclmellJ) +8h56SOC(10M0F),AC RW 1137 16S S(r) wn I . , ... +8h,67S'C(12M°F),AC RW 642 125 56(0 51(0 I( . ...

Nanhosparhglng l o x l%mm (4 x6 ia)

h e 32mm(1.25in.)

15 mia, 815 T (MOO 'F),AC

925 OC (lm) OF), aoneakd, AC

925 (1700 OF), MntaleQ AC

I h,81SOC(15000F),AC 19 mm (0.75 ia) (- S p e c i m C ~ ~ +4 h. 525 OC (975 'F).AC (C) 1206 175 ... ... W) W)

(a) Fwr-point loaded, aOw-bend @t. (b) Heat treatmant detnlla not ghrsn (c) lket d e w not given, (d) 1MXI.h exposure at 28.6 O C (550 OF) under 172 MPa (26 W load, waled to m m tempereture and tested. (e) Slow-bend teete. (0 Compact-- teete. Source: Beta lltaniurn Alloye, R Wood, MCIC-7a-11, Bettelle Calumbue hboratories, 1972

Ti-1 OV-2Fe-3AI Common Name: Ti4 0329 UNS Number: Unassigned

Ti-10-2-3 is a high-strength titanium-base alloy. Metallurgically it is a near-beta alloy, and it is capable of attaining a wide variety of strength levels depending on selection of heat treatment Major advantages of this alloy are its excellent forgeability; its high toughness in air and saltwater environments; and its high hardenability, which provides good properties in sections up40 125 mm (5 in.) thick. It is used in the a m - space industry for applications up to 315 "C (600 OF).

Amajoradvantageof'IF-10-2-3 overcommercially avdlablealpha- beta compositions of similar strength levels is its toughness in air and salt water environments. This near-beta alloy was &veloped primarily for high-strength and toughness applications at temperanves up to 315 "C (600 OF) and tensile strengths of 1240 MPa (180 ksi) in order to provide weight savings over steels in airframe foqing applications. Of special interest for high-strength forgings for aircraft, it is being used for components by much of the aerospace industry.

Chemistry and Density 'K-10-2-3 has a near-beta composition and is slightly more beta sta-

bilized than Ti-1 1.5Mo-6Zr-4.5Sn (Beta 110. Density, 4.65 g/cm3 (0.168 i b h 3 )

Product Forms Ti-10-2-3 has the best hotdie forgeability of any commercial tita-

nium alloy and is often used for near-net-shape forging applications. Mill products are billet, bar, and plate.

Product Conditionhlicrostructure Developed for use in the aerospace industry, Ti-10.2-3 combines

many of the advantages of the metastable beta titanium alloys without sacrificing certain inherent alpha-beta characteristics. It shows excellent hardenability in section sizes up to 125 mm (5 in.), but also demonstrates g o d short-msverse ductility. In the solution-treated and aged condition, this alloy maintains greater than 80%. of its mom-temperature strength at 3 15 O C (600 OF) and has creepstability characteristics similar to those of the alpha-beta alloys at this temperature.

Applications l3- 10-2-3 is used at temperatures up to 3 15 OC (600 "F) w h m me-

dium+-high strength and high toughness are requind in bar, plate, M forged sections up to 125 mm (5 in.) thick. It can be heat tteated over a

Ti-lOV-2Fe3Al I357

wide strength-toughness range, allowing the tailoring ofproperties. It is employed for applications requiring uniformity of tensile properties at surface and center locations. Specific applications include aaospace air-

frames hot-die and conventional forgings, and other forged parts in a wide Variety of components. The major user, Boeing, us- tbe alloy up to 260 OC (SO0 OF).

fClOV.2WAI: Sp8cMcatknr and comporltlonr

SDeeMatbn Ddurstbn Dcgiotbn Al C R B N 0 V Y other

AMS 4986 FrgSK)A 26-3.4 aos 1.622 0.015 On5 0.13 9-1 I aoos oTo.3:bln

AMs4984 Frg STA 2.6-3.4 0.05 1.6-2.2 0.015 Am4987 Prg STOA 2.6.3.4 0.05 1.62.2 0,015 0.05 0.13 9.11 0.m oTa3;baln

CammMon, wt%

USA

AMS 4983A FQ STA 2.63.4 0.05 182.2 0.015 0.05 0.13 9-11 0.00s CtT0.3;brlTl O M 0.13 9-11 0.W5 oT0.3;balll

Ti-1 OV-2F8-3AI: Commerclat compositions

thmwltka, % SJeCinmm Wnatbn h m l ~ ! b n A1 C FC B N 0 V Y Otkr Jaw0 Kobe KS10-2-3 Ber Rg STA 2.b3.4 1.622 0.015 0.05 0.13 9-11 baln USA Ttmet TIMETAL10-2-3 FQ 2.63.4 1.622 0.015 0.05 0.13 9-1 I balm

Care must be taken in analyzing this fatigue data and comparing to a given set of conditions as there are so many variables, including specimen m, surf= finish, R - d o , and loading condition f a ton such as load controlled or strain controlled frequency, and wave form.

The Mgkycle fatigue stmagth is a function of the tensile strength as one might expect. Generally the S-N curves quite flat Direct aging (with no solution treatment, which can be used over a limited thickness range) has a pronounced advantage over the solution mted and aged

condition. This is attributed to two factors, the minimization of grab boundary a and the precipitation of a finer, more uniform dispersion of aged a when using a dk.ect age. A pr;narY a grain effect has been recently tepotted (see bottom right figure). rite effect o f w temperatun on fatigue properties is also illustrated. Again, one might expea the h i g h strength condition to have a lower fatigue debit as a function tern- perature than the lower strength conditions.

01 , , . . , , . ., , , , , . ...I . . . , , . , . I . . , . , 1 os 10' 1 o5 10'

stress Eydes

I i 806-

1131 MPa (184 lap1) UTS, L-T 1124MPa(183ksr)WS,L

4340 bar, MI4 Hdbk . - . 1424MPa(2OBksI)UTS

Id 10' 106 GyAatl to failure

Ti-lOV-2Fe3AI: EEed of temperature on axial fatigue. Axial fatigue of Ti- 10V-2Fe-3AI bar s t w k in ths STOA (solution treated and averaged) condition. SpecimsnS were taken fromrwnd bars 75 nun (3 ih) in diameter that hadbeen solution trsa(ed 1 hat 760 OC (lW OF'), furnace cooled, ovaaged 8 hat 565 *C (1050 OF), and air cooled. Teots were conducted at a 8 t n i ratioof R = 0.1 and a frequency of 20 Hz. Source: 0. Deel, "Eagineering Data on New Aerospace Smcturrrl Mateiak," Air Force Uat#ials Laboratory, AFMLTR-77.198. Wright Panemon AFB, I!377

TGlOV-2FB-JAI: Compvbon ofmumth PPtlgue stmngtk Source: 1. qfMer- ah, March, 1980


Lowlcycle Fatlgue

160 R=Q1 1

ld 104 10' 10' 10' 10' cyw to fallurn

'N-lOV-2Fe-3Ak Fstllpscdsmooth Specimens (ll9OMPa UTS).'II-lOV-2Fe- 3Ak Soludon aaactd aad aged (STA) epsdmens were t a b fmm @ hot die forp iup, eolulion tmtted at 30 OC (54 "p) below tmnsus tempsrahua, water quenched, pad agedto astrwgtblevel of 1190 MPa (175 ksi). Ti-lOV-ZFb3AI di- mt aged spechem were B bot die forged, post-forge m k d a t a nte of5 OC/s (9 'F/s), and aged to 119OMpa (172 hi). Fatigue tests for S T A s p i m m wcre per- f o r m e d ~ ~ ~ ~ p i m e m 3 nun (0.125 in.) in - With &= 1, R m O . 1 , a d f% qwncyof3oHz, low sties5 ground Fatigue test fordksctagsd lpscimeapm patormsd on 3 nun (0.125 in.) dim samples witb Kf = 1, R = 0.1, and frssueaoy of 125 Hz, mfaw were low rtrurognxladandslblished, Source: 0. Kuhl- man, A. Clukmhem ',T, WI, R. Pishko.ar~~I0.Tdade,LCF,Fracture'Ibughnesa aad FatigWlFetigue Cnxk Rapgation Ftmbmce Optimization in 'II-lOV-2Pe- 3A1 AUoy lhmgh MicrosaUcrunl Modif idon, in Micmsfwtun, Fmefun lbughness, and Fktigw Crack Growth Ra@ in miurn AUoys, A. Chalcraberd a n d J . C . ~ B d . , T M S / A I M B , 1987,p 171

- 160

-140

- * i tm

- 120

Ti-I OV-2Fe3AI I 359

8001 . , , .... 4 . , , . ...., . . . . . . . . I . . , , ,p 1 o3 10' 10' 1 0' 1 o7

Cycles to fallurn

Ti-lW-2Fa3AI: Fatigwofnnooth specimens Ill00 MPPUTS). "l-lOV-2Fe- 3A1 solution &eated and aged (STA) specimens w m taken from p hot die fwg- ing , solution u e d at 30 "C (54 "p) below the 0 transus temperatun, water quenched andagedtoa strength level of 1100MPa( 160ksi)."l-lOV-2Fe-3Al direct aged specimsns were p hot die forged post-forge cooled at arate of 5 'C/o (9 WE), and aged to the desired strength level. Source: G. Kuhlman, A. ChababSrti, T. kz1, R. Pishko, and G. Terlindt, LCF, Fracnvt Toughmess, and FatiguelFIItigue Crack Propagation Resistance Optimization in 'K-IOV-2Fe-3Al Alloy Through Micrastructwal Modification, in Microstructun,Fracture Tbughncss, and Fa- tigue Crack Gmwrh Rare in litmiurn Alloys, A. Chnkxabiuti and J.C. Chesnutt, F!d.,TMS/AIME. 1987,p 171

1200

1 o4 1 o6 1 d 10' Cydm to failure

RlOV-2Fe3AI: RT ax&l fatigue oeSTAforgings. Boeing 747 lower link fitting, p forged with a-p (90%) finish: 775 'C (1435 OF), 2 h, AC + 770 OC (1425 "F), 2 h, WQ + 5 10 T (950 "p), 8 h, AC. Soum: Aemspucc Srrvctuml Metals H&bo& Vol4, Code 3726, Battelle, 1972

m O t P t o a 266MPatP

l o 3 10' lo6 10' id 10' cycles

Ti-lOV-2Fe-3AI: S/N data at two mean crtr#ls kveh The fatigue endurance limit is influenced by the position in the billet, i.e. superior fatigue endurance val- u e ~ were obtained from the outer portion more heavily waked area of the billet ring,althoughtheefht wasconsiderednegligible. Source: D.P, Davies, Effect of Heat 'haknent on the Mechanical Properties of 'IF-lOV-2Fe-3Al for Dynami- cally Critical Helicopter Components, 7th World Conf on 'Ktanium

O*$ . . . , ...,I . . , , , , .d . . . . ,,.A , , , . . . , .( , . . . ,,.A . , - 10 14 loa 10' 10' id 10'

cydes to fallure

Ti-lOV-2FeJAI: LCFllndershaln controLAllofthe forgingheataeatcombi- nations tested in this study cyclically ~0fhIKd. Most of the stress duction occurred early in the test. For relatively short lives in low-cycle fatigw, the load never completely stabilizes. 'K-lOV-2Fk-3Al forgings werepmessed under four differem conditions to an average yield strength of I103 f 12 MPa. Lowcycle fatigue testing was performed on a closed bop hydraulic MTS Systems machine sccotding to ASTM E606, "Standard Recommended Rectice far Constant Am- plitude Low Cycle Fatigue 'lbting." R =-I, and constant strain rate was 0,011s. Source: R.Carey,R.Boyer,andH. Rosenberg,FatigueRopertiesof'll-lOV-2Fe- 3Al in ?itaniwn, Science and Technology, M12,O. Liitjering, U, Zwicker, and W, Bunk, Ed, Deuwtte OeScUschaft Nr Metallkunde, e.V., Oemwy, 1985, p 1261


1 10 lo* 10' 10' 10' 10' 10' cycles to failure

Ti-lOV-2Fe3Ak LCFundv load control TL- IOV-2Fe-3A1 forgings were processed under four different conditions t~ an average yield strength of 1103 f 12 MPa. Low-cycle fatigue testing was performed on a closed loop hydraulic MTS Systems machine according to A m E606, "Standard Recommended Ractice

Boyer, and H. Rosenberg, Fatigue Roperties of 'K-lOV-ZFe-3A\ in 'IYfanium, Science a d Technology, Vol2,G. Utjenng, U. Zwicker, and W. Bunk, Ed, B u t - whe Gesellwhafl fUr Metallkunde, e.V., Germany, 1985, p 1261

faCDnstamAmplitudeLa~CycleFatigueTesting."R =-l.Source: R. C-y,R.

R 0.1 800

100 985 MPa (140 M) UTS 4

1103 MPa (160 ksl) UTS

AFM-TR-80-4168 1193 MPa (173 ksl) ufs, 20 Hz

cycles to failure

Ti-lOV-2Fe-3AI: Fatigue dSTA notched [1yI - 3) sppecimens. TI-lOV-2Fe-3Al solution treated and aged (STA) specimens were taken from p hot die forgings, solution treated at 30 OC (54 "P) below the @ transus temperature. water quenched andagedtoastrengthlevelof965 MPa(l40ksi). FatiguetestsfbrSTAspecimens were performed on specimens 3 mm (0.125 in.) in diameter with Kl = 3, R = 0.1. and a frequency of 30 Hr, low s h w s ground. Source: G. Kuhlman, A, Chakra- b d , T. Yu, R. Pishko, and 0. Terlinde, LCF, Ftacnrre Toughness, and FatigueRa- tip Crack Rqagation Resistance Optimization in TL-10V-2Fe3AI Alloy 'Ihrough Mimtwrura l Modification, in Microstructun, Fracture Toughness and Fatigue Cmck Gmwrh Rate in ntanium Alloys, A. Chaluabarti and J.C. Chesnun Ed., TMWAIME, 1987, p 171

R I0.1 1200 1

10s lo4 10' $0' 10' 10' Cycles lo fallure

TI-IOV-2Fe-3AI: Notrhed and smooth CPtIgue w TIbA14V. S-Ncwes for ll- lOV-2Fe-3AI(strengthlevel, 965 M h o r 140ksi)Mdll-4A1-4V(s~gthIcvel, 896MPaor 130ksi),TI-lOV-2Fe-3AI specimens wentakenfrom~ hotdieforg- ings. solution treated at u) OC (54 "p) below the @ m u s temprrahlre, water quenched, and aged to a strength level of%5 MPa (140 ~ ) . TidAl-4V isotha- ma1 forgings were annealed to a minimum strength level of 8% M h (130 ksi) with an actual ultimate tensile strength of loo0 MPa (145 hi). Fatigue tesb were p e r f o d on specimens 3 mm (0.125 in.) in diametcr with Kt = 1 or 3, R = 0,1, and a frequency of 30 Hz, low stress ground. Source: 0. Kuhlman, A. Chakra- bani,T. Yu, R. Pishko, andG. Terlinde, LCF, F r a c t w T o u ~ a n d F a t i W a - tigue Crack Propagation Resistance Optimization in TI-lOV-2Fe-3AI Alloy Through Microstructural Modification, in Microstrucrurr, Fmctun Torrghness, and Fatigue C m k Growth Rate in 'IYtanium Alloys, A. Chakrabarti and J.C. Chesmua, Ed.,TMS/AIME, 1987,p 171

1000

\

1 o4 Id 1 0' 1 0' cyclee to failure

TT-fOV-2Fe-3AI: Smooth and notched Lstigue d STA forging& Heat m- ment 815OC(15Oo0F), 1 h,AC t620°C(11500F),8h.AC.Sourcc:Aemspace Stwctuml Metals Handbook, Vol14, Code 3726, Battelle, 1972

TI-lOV-2b-3AJ / 361

K, = 3.3 CL

nro[ . . . , . . . ., . , . , . , . ,, , , . . . . & 1 o4 1 0' toa I o7

cycles to failure

Ti-lOV-2Fe3Ak Notched fulgue of STA foq#ng. Boeing 747 lower link fitting; ~forgedwitha-~(S2O%)fmish;775 oC(1435°F),2h,AC+7700C(1425 "P), 2 h, WQ + 510 OC (950 "p), 8 h, AC. Source: Aempuce Srnrcruml Met& Handbook, hi 14, Code 3726, Battelle, 1972

0 L f 500 D

2001 , , , , , ..., , , , , , ..,, . . , . , ..., . , . , 1 o3 I 0' 1 OK 10' 10'

Cycles to fellure

TelOV-2Fe3AI: Fotiguewith hgte-hole notch. Boeing 747 lower link fitting; B fwged with a-p (00%) finish; 775 OC (1435 "p), 2 h, AC + 770 'c (1425 "p). 2 h, WQ +510 OC (950 ORp), 8 h, AC. Source: Aerospm Strvctnml Metah Haad- book, W 1 4 , Cods 3726, Battelle, 1972

m a t R = 0.05 Kf = 3.0

-

m[ :,;; .,,,,_ . , --, , , , . 275

10' 10' 1 0' 1 o7 cydecl to failure

TI-lOV-2Fe-3AI: Fatigue with dopbbboh notch. Bocing 747 bwer link fitting; p forged with a-B (80%) finish; 775 'C (1435 "p), 2 h, AC + 1425 "p), 2 h, WQ + 5 10 'C (950 OF), 8 h, AC. Source: Aerospace Structuml Metals H d o o k , %I 14. Code 3726, Battelle. 1972

Gross area stress, 296 MPa (43 ksi)

R = 0.05 0 Kf = 2.93

Five tests each 1

[ 9WMPa(140ksi) - I 1 I Gross area stress, 345 MPa (50 ksi)

8 R = 0.05 K, = 2.93

Five tests each 1

Ti-lOV-2Fe-JAk Notched fatigue perfonaance of forgings. Notched fatigue (cycles to failure) of pancake forgings vs amount of work at (a) strength level of 1310 MPa(190ksi)and(b)seengthlevelof865 MPa(l40ksi)and 1034MPa(l5Oksi).Logaveragelivesandscat1erbandindicated. ptransus temperaturewas810OC(1490 OF). Pancake forgings were produced by forging at temperatures 10 to 25 "C (18 to 45 OF) above the transus to produce SO to 70% thickness reduction. Additional reduction of 2 to 58% was accomplished by forging in the a-P range (10 to 25 T, 18 to 45 OF, below the fi t.mmus temperature). Source: R. Boyer and G. Kuhlman, Processing Properties Relationships ofl'l-IOV-2Fe-3Al. Metall. Trans. A., Vol 18,1987,~ 2095

362 / Titanium Alloy Fatlgue Data

K,'s of 2.4 and 2.5 nspeEtively, show a much larger difference in prop- d e s than can be ascribed to the difference in K,. Microstructure has virtually no effect on the fatigue smgth at the high strengthlevel (190 hi), but does have an influence at lower tensile saargth levels for a Kt of 2.93. Higher amounts of a/B work, which result in a mofe equiaxed primary a, appeers to have a negative effect on fatigue saength for the lower strength conditions ( 1 4 and 150 hi).

Room Temperature The notched fatigue strength at a K, = 3 decreases as the strength

level increases. (At al l strength levels it is superior to that ofTL6AlW). The drop in fatigue strength as the strength is increased is awibuted to i n d notch sensitivity at the higher strength levels, leading to earlier crack initiation. Data from several notch geometries sre presented. The effect of notch geometry is shown. A round and a flat specimen, with

Eievated Temperature

1 o3 I 0' 10' lo' 1 o7 stress cyck%

Ti-lOV-2Fe-3Al: Fatigue of notched STOA bar. Specimens were taken from round bar 75 mm (3 in.) in diameter, solution treated at 760 OC (1400 'F) for 1 h, furnace cooled, overaged at 565 'C (1050 for 8 h, and air cooled. Fatigue teat- ing m a t R = 0.1 and a fnquency of 20 Hz. Soume: 0. Deel, "Engineering Data on New Aerospace Structural Materisls," Air Fonx Materials Laboratory, AFML-TR-77-198, Wright P a m AFB, 1977

140 LofQiinel loo0

UI , , .... , , ..... .1 . I , .,.....I , . .__.. J . . , .

Cycles to fallurn

Ti-lW-ZFa3Al: Smooth and notched fatlgue at 200 O C . Solution treated and aged75mm(3in.)diambar~edatf60'C(1400'F), 1 h,FC+565'C(1050 OF), 8 h, AC. Source: 0. Wl, "Engineering Data 011 New Asrospaoe Structural Materials," Air F m e Materials Laboratory, AFMLTR-77-198, Wright Patter- son AFB, 1977

AT R t O . 1

1500

0 . . . , . ...I . , , . , .,.I . . , . . . . d . . , . . , ,? . . 10" 10' lo6 10' 10' 1

cycles to failure

TI-lOV-ZFe-3Al: Smooth and n&W fatigue at RT. Solution aatedand aged 75 mm (3 inJdiambartmtedat 7 6 0 T (1400'F). 1 h,pC +565 OC (1050°F), 8 h. AC. Source: 0. Deel, "Engineering Data on New Aerospace Structural Mated- als," Air Force Materials hboratory, AWL-TR-77-198, Wright Pattersoam, 1977

UI , , , ... & , , , , ,,., , ,,,,.,A , .

cycles to failure

Ti-lOV-ZFe3Ak Smooth and nolched fatigue at 425 'C. Solutioll mated and aged75 mm (3 in.) diambartreatedat 760 'C (1400 OF). 1 h, FC t 565 'C (1050 OF), 8 h AC. Source: 0. DeeL "Engineering Data on New Aerospace Structural Materials," Air Force Materials Labonuory, AFMLTR-77-198, Wright Patter- sonAFB, 1977

TElOV4Fe3AI / 363

250'

Early work with powder metallurgy compacts indicated a debit in comparison to wrought forgings. Thermomechanical processing can be seen to have an influence. Of the two compaction techniques studied for pre-alloyedpowder, the compaction technique does not appear to be im-

portant. The blended elemental compact fatigue perfonnance could also be improved by thmmechanica l processing and/or the use of low C1 powder.

\ . - . . . . D -80 E '

, , . . ...., , , , , ,..., , , . , ..,., . , , , &40

TI-lOV-2FeSAI: ktlgua In notched speclmsnr for several product fOm8 In high4trength and lowatrength COndkh8

Roduc( U l h B b t . e d k ~ i 7 t l l ha -LB term m kd htlpDeUib CsslrndwroupM iwmcnnal eq ingr 13001380 18am m m CoDventionalforgings 12301350 178-396 so an

ZScr /Bd lOs0 152 a3 300

10KL1100 154-159 25 700

PbWC&pagingS 12601345 183-195 50 OOO 43% rr/8 worlr 105&1070 152-155 50 OOO

Expusions 1105.1 175 1w1m 32 5do

Realloyed HIP 1345-1415 195.205 16 90 Ipaihermally forged 1125-1145 163-166 53 300

PFi

Noh'&& f r e q u e n c y ~ 3 0 H z a n d R = 0.06, WithK, = 2.99 d t e e t e performed at &resa level of 346 MPa (50 kei). Source: R Boyer, D. Eylon, and F. Froes, Comparative Evaluation of 'R-lOV-2Fe-SAl W, P/M and Wrought Pmduct Forme, Titanium, Schm and l k h d a g y , Vol2, G. LWjering, U. Zwdcker, and W. Bunk, Ed.,DeubcheGesellechaftAtr?detallkuade, e.Y. Germany, 1986, p 13M

c L

10' 1 0' los 1 0' 10' Cycles to failure

Ti-lOV-ZFb3AI: Fatigue ofcmt and wrought specimens. Smooth specimen fatigue for (A) cast and wrought plus isothermal forge, ultimate tensile strength= 1300 to 1380 MPa (188 to 200 h i ) ; (B) pfoalloyed P/M HIPplus isothermal forge, ultimate tensile strength = 1345 to 1400 MPa (195 to 203 ksi); (C) prealloyed HIP, ultimatetensilestrength= I310MPa( 19Oksi); (D) P/S + HIP, ultimate tensik stnngth 1228 to 1275 MPa (178 to 185 h i ) ; (E) PB, ultimate tensile saength= 1195 MPa(173bi).Curvesnpresemtdatalowerlimits.Testfrequency waa 5 Hz and R = 0.1, Source: R. Boyer, D. Eylon, and F. Froes, Comparative Evaluation of 'K-IOV-2Fe-3AI Cast, P/M and Wrought Roduct Forms, in 7ito- nium Scienceand7kchnology, bI2.G. LUtjenng, U. 2wickw.and W. Bunk,Ed., Deutsche Gesellschaft fUr Metalhnde, e.Y, Germany, 1985, p 307

7 \ L

Sldegraoved rwnd specknens, -80 !! K,=2.4 3

Single open hole spedmens, 66.12.5 .

300 - Single open hole spedmens, JPa6

&= 2.5 300

Jpo 10' 10' lo8

cycles to failure

"i-lOV-2Fe4AI: EBect ofnotch geometry on fatigue rtrragth. Forgings were heat treated to a swngth level of 1241 M h (180 ksi). Flet sheet-type specimens with holes drilled to a notch factor Kt = 2.5 and round side-grooved specimens with Kr = 2.4 were used. Heat treating and machining squences were the same in both cases, Source: R. Carey, R. Boyer, and H. Rosenberg, Fadpe Roparties of 'II-lOV-2Fe-3A1, in ?iranirun, Science Md Technology, Vol2,G. Mtjering, U. Zwicker, and W. Bunk, Ed., Deutsche Gesellschaft f i r Metallkunde, e.V., Ger- many, 1 9 8 5 , ~ 1261

loo0

\ \ 4130

"m 500 10' 10' 10' 1 oe 10'

CyGles to falbre

Ti-lOV-2Fe-3Ak Fatigue in powder compacts. S-N curve for powder compacts consolidated by rapid omnidirectional compaction (ROC) by hot isostatic prrss- ing. Bothspecimens we~eheateeated.Chemicalcompositionofthealloy was3.0 wt% Al, 0.065 wt% C,2.1 wt% Fe, 0.0063 wt% H, 0.0093 wt% N,0.1485 wt% 0, 92 wt% V, and 0.006 wtW W. Processing parameters for consolidation (ROC) were775 "C (1425 "F)at830MPa(l20bi), ln-sdwell,aircool.Processingpa- ramctcrs for HIP were 790 "C (1450 "P) at 103 MPa (15 ksi) for 20 h. Heat treat- mentwascaniedoutat745°C(13650F)for 1 hwaterquench,and490'C(915 OF) for 8 h, air cool. Fatigue tests were performed at room t e m p t w e on a8eTvo- hydraulic MTS machine. Constant load triangular waveform cycling was done at R = 0.1 and a frequency of 5 Hz. Source.: Y. Mahajan, D. Eylon, C. Kelto, and F. Roes, Evaluation of 'K-lOV-2Fe-3Al Powder Compacts Roctuced by the ROC Method, MeralfmderRep., Oct 1986, p 749

364 /Titanium Alloy Fatlgue Data

Using conventional processing and heat treatments, the crack growth rate. (dnldh') of this alloy i s essentially independent of microstructure, strength level and test environment, and, in air, is similar to

that of mill annealed Ti-6Al4V. Aging to produce the omega phase significantly reduced MdN, but, as mentioned previously, this is not a practical microstructure to use.

lo.'$ , . , . , , , , I , , , . . . . 1 10 100

Stress-intensity, MPeJm

Ti-lOV-2Fe-3AI: Crack growth in two aged conditions. Source: T.W. Duerig and J.C. Williams,Overview: Mimstructunand Roperties of BetaTItanium Al- loys, in Beta Titanium Alloys in the 1980k, R. Boyer and H. Rooenberg. M., TMSlAlME, 1984, p 44

1 10 100 Stress-intensity range, MPaJm

Ti-lOV-2Fe3AI: FCG with low aspect ratio ofprimary CL. Chemical composi- tionofthealloywas33,2wt%Al,0.03 wt%C, 1.8wt4b Fe,O.005 wt%HH.O.O1 wt% N, 0.087 wt% 0, and 9.7 wt% V. Material was p forged then a-P worked to effect an additional 55% reduction, followed by heat treatment at 750 OC (1380 "F) for 2 h, and water quench. aged 550 "C (1020 "F) for 8 h. Ultimate tensile strength wts 1009 MPa (146 h i ) . Tests were performed in air at morn temperature, with Haversine waveform and R = 0.10. Source: G, Ycder, L. Cooley, and R. Boyer, Microshucture/Crack Tolerance Aspects of Notched Fatigue Life in'K-1OV-2Fe- 3A1 Alloy, in Micmstnrctun, Fractun Toughness and Fatigue Cmck Growth Rare in Titanium Alloys, A. Chakrabarti and J.C, Chesnutt, Ed., TMSIAIME, 1987, p 209

10 100 AK, bidin.

TLlOV-2Fe-JAI: Cmck growth in air and 3.5% NaCI. Superimposed air and 3.5% NaCl fatigue crack propagation rate scatterbands for Ti-IOV-We-3AI, R = 0.05, frequency 1-30 Hz, various orientations. Source: R. Boyer, WestTech, 1981

1 o4

8 E E

1" g 10'' a d

1 od 1 10 100

Stress-intensity range, MPalim

"i-lOV-2Fe-3AL: FCG with high aspeft ratio of primary a. XqepiXaX xop- ~OQLROV o # q e alrlioy QKUT 3.2 m% AX, 0.03 on% X, 1.8 WE% a, 0.05 m% H, 0.01 cor4b N, 0.087 an% 0, avS9.7 on% 4 MarepraXawur fi forged then a-fi worked to effect an additional 2% reduction, followed by heat treatment at 750 "C ( I 380 "F) for 2 h. and water quench, aged at 550 *C (1020 OF) for 8 h. Ultimate tensilestrcngth was 1067MPa(154ksi).~stswereperformedinairatroomtem- perature, with Haversine waveform and R = 0.10. Source: G. Yoder, L. Cooley, and R. Boyer, M i m s t r u W m c k Tolerance Aspects of Notched Fatigue Life in 'K-IOV-IFe-3AI Alloy, in Micmstructun ,Fmctun Toughness and Fatigue Crack Gmwth Rare in Titanium Alloys, A. Chakrabarti and J.C. Chesnutt, Ed., TMWAIME 1987, p 209

1 10 100 Stmsalntmslty w, MPaJm

Ti-lOV-ZFe3AI: FCG ultb high MpWt ratio d p r i m p ~ U. Chemical ~ p o - sitioo of the alloy was 3.2 wt% Al, 0.03 wt% C. 1.8 wt% Pe, 0.05 w% H, 0.01 wt% N, 0.087 wt9b 0, and 9.7 wt% V, Material was p forged then a# worked to effect an additional 2% reduction, foliowed by heat tre.annent at 750 "C (1380 OF) for 2 h, and water quench, aged at 4% "C (255 "F) for 8 h. Ultimate tensile saength was 1288 MPa (187 hi). Tests were p e d m d in air at room temperature, with Haversine waveform and R = 0.10. Source: G. Yoder, L. Caoley, and R. Boyer, MicrostruchueKwk Tolerance Aspects of Notched Fatigue Life in Ti- lOV-2Fe-3AI AUoy, in Microstructure, Fracture Toughness a d Fatigue Cmck Growth Rate in nranium Alloys, A. Chakrabarti and J.C. Chesnutt, Ed., TMWAIME, 1987, p 209

"'1 1 ; E

% i

E

r! 1 104:

lod

1 10 100 Stms-lntenslly, MPa4-n

T1-10V-2Fe-3AI: FCGh STAanddLect apcmdition&TI-lOV-2Fe-3AlSTA specimens were taken from p hot die forgings solution treated at 30OC (54 OF) be- law i3 transus temperature, water quenched, and aged to a strength level of 965 M h (140 a). Ti-lOV-ZFe-3AI dirrct aged specimens were p hot die forged, post-forgecooldatarateof5 'C/s (gOF/s),andagedtothedesiredsaengthLe~I. FatigueaackpropegationtcstsforSTAspecimens wereperfmedonspccimens 6 mm (0.25 in) thick and 37 mm (1.25 in.) in length and width with R = 0.1 and a frequency of 30 Hz, compact tension. Fatigue crack propagation mts for direct aged specimens were performed according to ASTM E606 on 6 mm (0.25 in.) diameter specimens, low s m s ground, triangular waveform, 20 cycleshnin. R = 0. aud A = 1 .O, with a frequemy of 50 Hz, constant swain. Source: G. Kuhlman, A. Chlcrabarti. T. Yu, R. Pishko, and G. Terlinde, LCF, Fracture Toughness and Fa- tigue/Fatigue Crack Ropagation ResistanceOptimization iaT3-1OV-2Fe-JAI Al- loy Through M i c r o s ~ t u r a l Modification, in Micmstructun, Fracture %ugh- ness, and Fatigue Crack Growth Rate in Titanium Alloys, A. Chakrabarti and J C Chesnutt,Ed.,TMS/AME 1987,p 171

o HighatrengthTi-lOV4Fe3AI (1T MPa UTS)

1 10 100 Stresa-intensity, MPdm

Ti-lOV-2Fe-3AI: FCG h direct age d i d o n . 'IT-lOV-2Fe-3Al dim aged specimens w e n fl hot die forged, post-foge cooled at a rate of 5 "Us (9 "Fh). and aged to the desired strength level. Fatigue crack propagatioa tests for direct aged spcdmens w e n pcrfomed according to ASTM EM)6 on 6 mm (0.25 in.) dim specimens, low stress ground, triangular waveform, 20 cycledrnin, R = 0, A = 1 ,O, mutant shain. Source: G. Kuhlman, A. Chahbam *, T. Yn, R. Fishko, and G. l'krlinde, LCF, Fracture Toughness. and Fatiguflatigue Crack Ropagatim Re- sistance Optimization in Ti-lOV-2Fe-3Al Alloy Through MIcrostruchrral Modi- fication, in Mkmstructun Fractun Toughness, a d FIlrigvr Crack G m t h Ratc in ntanium Alloys. A. Chakrabarti and J.C. Chesnua, Ed., TMWAME, 1987, p 171


The fracture toughness is strongly dependent on the tensile strength and the mimsnucture as reported by several authors. The processing, in terms of the amount of c@ work affects the toughness by modification of the mOrphOlOgy of the primary a. Higher amounts of a / p work, following primary working in the P-phase field, changes the primary a to a more globular morphology, which improves ductility at the expense of toughness. There would also appear to be an optimum amount of primary a to achieve maximum toughness (a 10% volume fraction of elongated primary a had significantly higher fracture toughness than 30 vol.%b). There seems to be a lot of variation in the toughness reported for powder compacts. There is some evidence that the fracture toughness is related to the volume fraction of defects in P/M products.

Stress C o d o n Resistance. The stress corrosion threshold has bear reported to be at least 80% of Kb except when it is stressed in the shon transverse direction, where it is 70% of Kb,

TI-1 OV-2FeSAI: Fmctun toughness for mveral product forms

ll-lOV-2Fb3AI: Room temprllture Charpy Impact toughness of STOA bar

Impsct touounhnesa Dimtbn J 8 . l b hgltudinal 35.9 265

40.7 30.0 40.7 M,O

Average 39.1 28.9

26.5 19.5 23.1 17.0

Average 25.8 19.0

Soum:AFAILTR-7&114

T r a n S V a D e 27.8 20.5

Uhkmb&Mik Pnslle ykM PLneatrsin P d W strength s t r e d tnetaretouehnwa ionn M h lusl MPE bi Lbngation, 46 M e d m lel.iilL mgh #he@ eMdftion isothermal fwglngs 1uM-1380 186200 I m I 2 5 5 174-182 3-6 29 26 Convenrional forgings 1230.1350 1761% 1145-1280 166.186 4-10 4460 40-54 F%rKake polsings 1275.13 10 185.190 1154 I160 167-168 5-8 47 43 ExlNsloPS 1240 179 1170 169 4 ... ... P/M highdrength Realloye4 HIP 1310 190 1205 175 9 ... ... Prealhyed, HIP+ isolhermal forge 1'345-1400 195-203 124s 1305 179- I89 64 28 25 PIS 1195 173 1110 161 3-5 ... ... P/s+HIP 1228.1275 178.185 1185- I245 172-180 7-9 28-29 25.26 Redudatmngthcondition Isothamal fagings 1060-1 1m 153.159 985-1060 143- I53 8-12 70 €4 Pancake forgings 965 140 930 135 16 100 91 Exlrusions 1110-1170 161-169 1m.1105 145-160 6-7 4548 41-44 PMReallGyedHIP+lsothennalfogc ll25.1145 163-166 10561090 152-158 13-15 55 50 PM, P/S +HIP llm-1160 162-168 10M1105 155-160 9-10 32 29 Castings 1105.1130 160-164 10101030 146-149 6-10 ,., ... A M S spcEMeDtion (forglngs) A M S 4984 1190 173 1 I 0 0 160 4 Cm 4D) 44 40 A M S 4986 1 loo 160 loo0 145 6(in4D) 60 55 Ah4S 4987 965 140 895 130 a (in 4D) 88 80

Spuree: K Boyer, D. Eylon, and Fa F m e , Comparative Evaluation ofTi-lOV.2Fe.SAl Cast, PM, and Wrought product Forme, "Uanium Science and 7kxhnolqgy, Val 2, G. Llltieriag, U. Zwicker, and W. Bunk, Ed., Deuteche Geeallschaft fib Metallkunde e.K, Qermany, 1985, p 1307

Ti-lOV-2Fe-3AI: Typical Q I p forged room-tsmpenture tensile properties and iracture toughness of forgings

Focpinb Ultimateykld Ultimate tensile Elonga- RedUctiop PLslw-strsin thkkness Orlentation/ itRneth(0.246 offset) strength tfon, of a m , lkcture twghnas mm In. h t k m MPI bl MI% kd 16 'k m J m Win 75 3 US,MC,C 1256.1263 182- 183 13 18- I325 191- I92 9-11 32-34 40.2 36.58

LWS.MS.C 1270-1283 184-186 1332- 1339 193-194 8-9 20-30 39.9 36.26 ST/S,MS,C 1214-1311 176-190 1283- I380 186200 5.9 12.34 43.2 39.26

50 2 US,MS.C 1249.1256 18 1- 182 1325-131 1 1sQ.192 8-11 27-35 35.4 3222 LT/S,MS,C 1270-1325 184-192 1346-1394 195402 5.8 12-27 35.1 31.88 ST/S,MS,C 1173-1141 170-173 11 94- 1242 173-180 13.14 46.59 ... ... m r 1173-1325 174192 1228.1394 178-202 5-14 12-59 -35 -32

25 1 l 4 , M S . C 1256-1283 182-186 1339- I342 194.1% 5-9 1425 30. I 2732 LTB, MS, C, 1221- I241 177-176 1270- 1270 184184 10-13 3648 30.9 28.05

Range 1256-1 3 1 I 182-190 1283-1380 18b2W 5-11 12-34 39-43 36-39

Range 1214-1256 176186 12701352 184-196 5- I3 10-48 30-31 27-28

Note: L, longitudinal; LT, long traaevme; ST, ehort traneverae; S, surf-; MS, mideurface; C, center. a + p forging WBB conducted at 760 'c (1400 O F ) with about 60% deformation, Eollowed by hand for%ng. The alloy waa double solution treated and aged. The Ant solution treatment waa performed close to, but M o w , the beta transus (788 to802 "C, or l4M3 to 1480 OF), fobwedby a elowml. The eeconddution treatment taokplace a t e temperature lowerthanthe first, followedbywaterquench. &wca: C. Chen and R Boyer, F'ractical Cmsideratione for Manufacturing High-Strength Ti-lOV-2Fe-3Al Alloy ForgnPe, J. Metals, July 1979, p 33

Tenslb strength, kal 120 140 160 180 200

... ". .. . ... ...... I

4 a 3

5m 750 lOaa 1250 1500 etnngth (0.2%), MPa

900 loo0 1100 1200 1300 1400 Tensile strengur, MPa

RlOV-2Fe3AI: Plsnedrdo frcletum toughma M UTS. Dam npnoent a composite offrechaa mu- values for~forged die forsings, B fbrgedblock forgings, pad forged plus a-p forged die fogingr of~-lOV-ZFe-SAl, Source: Metrrlrhkndbook Pwpertics &Selection: StOlnle~Strcla, ToolMatsriab, and Special-Pwposc Maltcriolr, W 3 . M d., American Society for MeealP, 1980

E M of Mkmtructure and Processing

LAR HAR LAR

1190 1726 12l8 1854 7.0 12.8 37.0 33.1

990 1436 1009 146.4 15.0 50.7 67.0 61.0 lCU2 145.4 la67 154.8 9.0 24.3 &I 1a4

368 I Tttanium Alloy Fatigue Data

1034 MPa (150 kd) E

_ _ - ~ . -- i a

E M of Procrsssing

1 1310 Mpp (180

0 0.02 0.04 0.08 0.08 0.1 Volume fraalar d deleca


Tl-lOV-2FdSAI: Fnoture targhnru oi powder cornpacts

Volume PlrJkrWd Ultimateten& Reductba Wrnin pLrablb.La lkakn ItrrnEtb lhPnxth of- taIketurc, i b h l m t o l l g h #

COnd#bd.) Dolatr O f M e C t l l MR ksi MPI M % % m4a M4ln

-0.15 wt% 4038wt% 0 As S i J l r € f S t Fc Inclulru,pms 0.067 883 128 966 140 2 1 2.1 29.7 326 @ W A C Incluliom,pora 0,069 945 137 %1 139 0,9 0.9 27.B 30.5 -O.iSwt% CI,O.l3wtk 0 As sinmat, FC Inclusions, pores 0.014 852 123 928 134 12.0 13.0 47.7 524

HIP(6oMP& lOOOoC), 1 h,AC ~ s i o n s 0.0055 977 142 1067 154 21.4 24.0 41.7 45.8 HIp(207~750oC)850oC 1 h,FC Inclusions 0.0027 928 134 1027 149 21.3 23 9 483 S3.1@)

4401 wt% CYC) Asrimaed,Fc Pom oms 786 I14 888 128 5.6 SB 62.9 69.1 €UP(#II h 8 a 7 5 0 ~ 8M°C, 1 h, FC None 1 1 1 996 144 1102 160 29.0 343 7S.S(b) 82.9

NOW Fmctu~ bughnew values were determhd with 1AW mm (0.6 in.) thick compact temion spechem and with 10.2 mm (0.4 in) oqum ma eection threepoi& band epxhena. Both t y p e e a f 6 p e C i m e n e ~ precmhd and tested in aamdanm with A8mb EsB8 at a rate d1.S wPaG/rn (1.3 kaic/m). (a)ChlorineEontentd etarblnBtitsniumpowder.(b)~~~~~,buree:N.Moody,W.G~,Jr., J . S m ~ , a n d J . C ~ T h e R o l e o l ~ l u p i o n a n d P o l e C D n t e n t o n t b e F r r e h r r e T o u ~ ~ P P o w d e r P r a e e a e e d B l e n d e d E l e m e n t a l T i - l O V . 2 F e - S A I , M i c r o s t ~ , R a c t u r e ~ ~ a o n d ~ i g r u e m P c k O r o w l h R o t e i n MwnAllqys,A Chahbnrti d J.C. Chemutt, Ed, W A I M E , 1987, p 83

B-AC Imlurions,prs 0.012 1033 150 1083 157 10.7 11.3 39.5 43.4

Till 5V-3Cr-3AI-3Sn Common Name: Ti-15-3 UNS Number: Unassigned

Ti-15-3 was developed during the 1970's on an Air Force contract and was later scaled up to produce titanium strip. It is a solute-rich beta titanium alloy developed primarily to lower the cost of titanium sheet metal parts by reducing processing cost through the capability of being strip producible and its excellent mom-temperanrre fmability characteristics. It cm also be aged to a wide range of strength levels to m e t a variety of applications. Althoughoriginally developed as asheet alloy, it has expanded into other areas such as fasteners, foil, plate, tubing, castings and forgings.

Product Forms Ingot, billet, plate, sheet, strip, seamless tube, castings, and welded

tube.

Product ConditionsJAAicrostructun, The alloy can be directly aged after forming. However, strength will

vary depending upon the amount of cold work in the part. Heating times prior to hot forming h u l d be minimized in order to prevent appreciable aging prior to forming.

Chemistry and Density Appiica tions Ti-15-3 is fomulated by depressing the beta transus with vanadium

andchromiumadditions. It is less beta-stabilizedthanTi-13V-llCr-3AI. Ti-15-3 is used primarily in sheet metal applications since it is strip producible, age-hardenable, and highly cold-formable. It is used in a va- Density, 4.76 g/cm3 (0.172 l b h 3 )

TClSV-3Cr-3AHSn I371

riety of airframe applications, in many cases replacing hot-fmed "I- 6A1-4V. Ti-15-3 can also be produced BS foil, is au excellent casting alloy, and has also been evaluated for aerospace tankage applications, high-strength hydraulic tubing and fasteners.

Airframe Structures. "I-15-3 possesses go& potential for lowering the manufacturing costs of titanium airframe structures. Studies on its formability led to use as the lower half of the A-10 fuselage frame. Production cost6 are lower than those for Ti-6-4. TI-15-3 welded tubing is used for pumat i c ducting, and Ti-15-3 sheet is formed into hemi- spheres and welded to fabricate fire extinguisher bottles on the Boeing 777. Other potentid applications for this material are as seamless tub-

TE15V9Cr9AMSn: Speclflcotlonr and Cmposltbnr

ing, wire, rivets, and foil for honeycomb structures. High-strength castings are in use.

Use Limitatio~. 'K-15-3, like other beta titanium alloys, is highly susceptible to hydrogen pickup and rapid hydrogen diffusion during heating, pickling, and chemical milling. However, because of the much higher solubility of hydrogen in the beta phase than in the alpha phase of titanium, this alloy has a higher tolerance to hydrogen embrittlement than the alpha or alpha-beta alloys.

Ti-15-3 can be welded in the solution-treated condition; however, welding is not recommended afta solution treating and aging. Care is necessary in pickling to minimize hydrogen absorption.

commltkn, Wt'k Sodkatbn Dalrnr lion Dcaalptkn Al Cr pe H N 0 sn V other

USA AMS 4914 Sh SpPSHT 2.5-35 25-35 0.25 0.015 0.05 0.13 25-35 14-16 COM;OT0.4;belTi A M 4914 Sh SpPSTA 25-3.5 25-3.5 0.25 0,015 0.05 0.13 2.5-3.5 14.16 C0.05 ;~OA;ba l" f

TI.15-3: 8mooth and notchsd fatlgw

hmt s t M a ) PmpaPtun SmoOth NObcbed(b1

oc OF m lur hQps bi -5 1 60 I24 105 241 30 24 75 655.158 95- I10 207-241 30-35 205 400 655690 95. loo 221.241 32-35

(a) Runout >loT +a, R = 0.1, maximum 419

h w n (b) Kk I 3. Source: Beta !lBanktm Auoye in the lm, RR. %yer and H.W. Roeenberg, Ed., W A I M E , W, p

Ti-159: C n c k g r o w t h a t A K = Z 2 M P a ~ ( 2 O O ~ Evaluating the data at AK = 22 M P a G (20 ksid ) shows d&N increases slightly as sheet gage increases. The combined salt weter plus frequency effeot is just at the Udetection limir statisticaliy.

FatSgue Crack Growth Ti-15-3 exhibits crack growth Characteristics much like mill an-

nealed Ti-6A14Y although Ti-15-3 is not as sensitive to environments such as salt water.

MdN at DK -22 MP.G(zB &h la' lp la' mm

EnvirownntaldPca AirvZOHz 9.12 232 Salt YSHZ 9.80 249

(3age effect 1.3 mm(0.050in) 8.58 218 2,5 mm(O.1Ooh) 10.33 262

Note: lbt e m r for h w data was estimated to be 12 x 104 md&e (0.49 x 10' idcycle). Source: Beta lhniurn Ways in the 1 9 W , RR Bow and HW. Rosenberg,Ed,TMwAME, lW,p429


10-1 2 I - 1 3

0.05 mrn (0.002 In.) sheet aged 16 hat SlO'C (950 O F )

1. Longitudlnal air

- 1 3

0.05 mrn (0.002 In.) sheet aged 16 hat SlO'C (950 O F )

1. Longitudlnal air

a, MPadrn

Ti-15-3: Crnckpmwth in sirandsalt solution. Source: Bera ntanium Alloysin a he 19803. R.R. Boyex and H.W. Rosenberg, Ed.. TMVAlME, 1984, p 420

a I

1 10 A& MPadm

14

Ti-153: Crack @ dnta for sheet. Specimeho were tested in tbe T-Lotien- talion. Sheet was aged at 540 "C (LOO0 "PI, 8 h. R = 0.1; frequency, 30 Hz, at 22 'C (72 OF). Source: Beta 7Timium Alloys in the 19803, R.R. Boyer and H.W. Rosenberg, Ed,, TMS/AIME, 1984, p 223

n-15-3: RT tnchrretoughneu of &set

Gace spccimn F n e m m t o r ~ [SL)

mrn fa orknmtia MPaG wiz 1-27 0.050 LT lo0 91

T-L lo0 91 1.78 0.070 L T 113 103

T-L 107 97

Note: Yield rrtrength of 1036 MPa (1M) kei) at RT. DL.ectianalty in &w, 3 to 4 Mh&i(3 to 4 biG). Intbbt vuiatlona can be up to U M P a G (10 W G ) . S o w : Be& ntcmiwn A l b h tha 19Ns, RR Bow and H.W. -berg, Ed., T M W W , 1984, p 416

~~~~~ ~ ~ ~ ~ ~ ~

nnaikykkl Ukitimrleblelk mngl- FnetuIe~hnt60 Hcrt 8t-h m h M, ad treatment orknmtka MP. kri rn kd 'k M W m lelh 8 0 0 ~ ( l 4 7 0 " F ~ 2 0 n r i ~ , A C , 4 8 0 ~ C ( ~ 5 ~ ~ I4h,AC L-T 1253 182 1376 199 6.2 44.3 40.3

T-L 1304 189 1421 206 6.6 46.8 42.6 8O0C(1470 T), 20 min,AC, 510 T (950 OF), 14 b AC L-T 1213 176 1337 194 ?a 42,l 38.3

T-I. 1263 183 1382 200 6.9 43A 39.5

NOW Hot rolled plate had B chemical cornwtion (wt'k) of 3.37 A, 0.004 C, 3.36 Cr, 0.17 Fa, 0.0081 H, O.M)80 N, 0.14 0,3.04 Sn, and 16.1OV. It was solution h t e d at 800 'c (1470 'F)forMmin, &coaled, then agedat 610 OC (960 OF)fOr8 or14 h Souroe: C. ourhi, K Suanagn,H. Sakuyama, and H. Takatoli EffscteoFThermomechanicPl ~VPriaMeeonMechenicalPropertiesofTi.16VSC1.SSn-BA1AUoyPlate,inaasigningWith~ItruJum, l W , p 1 3 0

TIMETAL@ 21 5 / 373

I I I . 0

0 5 10 15 20 25 Thkknese, mm

achievesnengthlevelsof1055MF(l(153Iwi)yieldstrsngtband 1117MPa(162 hi) tensile strength with 7.5% ductility. Compact tension spscimens with and without V-shaped side grooves (depth 40% original thickness) were tested on a mhydtaul ic machins ia load contml. S o w : P. Pmlose, Detaminaton of Fracture Toughacss from Thin Side-oroOved SpecimsnS, Eng. Fran. Mech., b l 26,1987, p 203

Ti-15-3: Fketrrrr targhnesa w shea thielmes& Alloy was heat tnatsd to

TIMETAL@21S Till 5M04A1-2.7N W.25Si Common Name: Beta-21s UNS Number: R58210

Tom O’Conrtell, TlMET

Beta-2 1 S is a very recently developed metastable j3 alloy that offers the high specific stnngth and good cold formability of a metastable p alloy, but has been specifically designed for improved oxidation resis- tana. elevated temperaaue strength, creep resistance, and thumal stability. Developing commercial applications in forgings include aerospace components and pmthetic devices. For the la#er application, with appropriate * thenomechaaical processing, Beta-21s modulus is cornparable to bone. For the former, Beta-21s may be precessed to very high smngths with excellent oxidation and corrosion resistance.

Strip is the main product form Beta-2 1 S is also well suited for metal matrix composites because it can be economically rolled to foil and is compatible with most fibas. Strip is available in gages from 0.3 to 2.5 mm (0.012 to 0.100 in.).

Chemisty. The composition of Beta-21s is based on the objective of obtaining a cold rollable, stripproducible alloy for economical processing into foil form. The key to processing an alloy to foil form is cold rolling of strip product. If an alloy cannot be cold rolled as strip, a hot process on a handmill using cova sheets to form packs for heat retention is the only other viable option. Although the pack process offers the opportunity to cross-roll to minimhe textun, it is nonetheless labor inten- sive and inheffntly a lower yield process.

In light of the fact that a cold rollable, strip-pmlucible alloy was of primary importanch it was decided that ametastable j3 alloy was the best approach. This meant that the ordinary obstacles to ov~come were the poor oxidation resistance and elevated-temperatun naechanical properties of this class of alloy. The initial approach was to concentrate on the Ti-Mo and Ti-Cr systems. Although the Ti-V system is most commonly

used for metastable j3 alloys (e.g., Ti-15V-3Cr-3Sn-3Al andTi-3Al-8V- fXr-4ZAMo), vanadium is well known for its detrimental effects on oxidation resistance. Conclusions of chemistry screening on oxidation resistance were as follows:

Silicon, niobium, hafnium, and tantalum were beneficial

num,andiK)I1. * Tin, z i ~ ~ n i u m , cobalt, yttrium, and iron were not benefi-

cial additione to a Ti-Mo base. 204bMoprovidesnoadvantageinoxidationreaistanceover 15% Mo. No additione were found that improve the car?DBion reeie- tanceofthe Ti-creeries.

d d i t i 0 1 ~ to the Ti-MO eyetern, 88 well 88 palladium, d d -

E f M ofoxygen. In a study on the e W of oxygen, oxygen levels up to 0.25% were found to have no significant effect on the strengthlduc- tility relationship of aged Beta-21s. Higher oxygen levels &grade duc-

nealed sheet material, which could advasely affect m e aspects of formability.

Oxygen absorption at the surface during exposure in air at elevated tempratwe degrades tensile ductility. The magnitude of the effect in sheet is dependent on the exposure time andtemperature and on sheet thickness. After a suitable heat treatment, Beta-21s is metallurgically stable for at least loo0 hup to 615 “C (1140 “p).

tility. Increasing oxygen decreases the work-hardening capability of Bn-

374 I Tttanlum Uby Fatigue Dato

! *

plrodad F o m and conditlonr. Ba-21S is available as cut a k t , strip, pk#,bar, billet, end blabm It is typically piovided inthe b s u - lution tnatsd cordition, which precipitates a to p v i d e strengthening on aging. The morphology and distribution of the adepend ontbe beat- @catnBnt tcnpahm and thc oxygen content. Lowar herrt-treatment tcnpmum and tdgk oxygen mmts nsult in homgeneous spheroiidal a; highs aging temperatures and l o w oxygen result in lath- type&

AppHertiom Beta-21s is most useful for eppriCations above 290 OC (550 'T), withthcnnal stability up to 625 OC ( 1 1 6 0 O F ) andcrcepre- sistaacecomparabletoTi-6A14V. Devdopingcommercialapplications

composites. Special pmpexfb include a modulus W is comparable to bone, improved oxidation resistance up to 650 O C (1200 OF), rtld nsis- $rice to rtaospace hydraulic fluids (e.g., Skydml).The latter M e a

include forstd prosthetic devices and cold rolled foil for metal matrix

have led to anumbecof aircraff a@ne applicntione. Exallentcorrosion ad hydrogen rmbrittlement radstancc have led to chemicpl pnd off- shors oil use.

sektedIbck.enw 1. W.M. Parrie and PJ. Bania, qeta-21S: A High-'bmpera-

ture Metastabh Beta 'I'itanium Wo$' Proc. 1990 TDAInt, cod, Orlando, 1990

2. W.M. pafiie and PJ. Bania, "oxggen EXbcts on the Me chanical properties OflmmAL 2lq. Pmc. 7th Int. ma" nium cod, SanDiegO, 1992

3. 5.8. human, "AHigh-Strength (hrromm ' Rnaiatant Tita- nium woy," Prac. 1990 TDAInt. Conf., Orlando, 1990

4. J.S. human, 'corrosion Behavior ofTlMETAL2lS for N v A p p l i c a w Proc. 7th Ink Titanium Cad, h D J 1 9 9 2

Mipimum 2 5 2.4 140 0.1s 0.2 ... a i l ... ..* ... Maxhla 35 3,O 16.0 0.25 0.4 0.05 0*15 0.05 081s ..I

Aim 3.0 2.8 1sn 020 03 t , . 0.13 8 . . ... bJ

(close-packed hexagonal a). Omega (m) also has been obsavcd, though it would not be a problem with t#oper heat treatment

TIMETAL@’ 21s I 375

Molybdenum improves corrosion resistance in reducing media, and this well-known effect is apparent when the corrosion rate of Beta 21s and grade 2 ‘IT arc COMpared in HCl solution (see figure). However, tbe inmased resistance from molybdenum in reducing media generally comes at the expense of resistance in oxidizing media. In this re@, the possible additive or synergistic effect of alloying on oxidation resistance was considaed during the development of Beta 21s. TIIC best overall oxidation resistance occurred with aluminum-silicon additions (see table). This alloying results in a slightly higher repassivation potential comparsd to ~ m o l y ~ n u m - c o n t a i n i n g titanium alloys (see table on next page).

Crwice ctumdon mbtance improves with molybdenum additions, and a chloride. crevice corrosion test (5% NaCl at 90 O C , pH ad- justedtoO.5and 1.0) ind i~ach lor idecnv i~c~s ionthresho ldbe- tweenpH 0.5 and 1.0.

Hydrogen Damage, Beta-21S retains ductility up to hydrogen levels of 2000 pprn. Tk percent of retained ductility versus hydrogen content is shown (see figure on next page). High hydrogen levels (zoo0 ppm) will slow down aging kinetics.

Apoy

Ti.15Mo-SPbWf 2.40 Ti.15Mo.sFsO.2si 1.52 Ti. 1sMo.sFb2Nb 1.17 TI-1mspe-WM).2s1 0.91 Ti-l5hfO-3Nb-l~-3Al 0.83 l¶-lShfO-SNM)JSi 0.7 1 ll- 1 Shb5Nb-3Al-O.SSi 0.60

Ti-lmb.SNb-3Al-0.5osi 0.90 Ti-lSMc-SNb-o.5Si 0.73 Ti-lW3Nb-1.5P-3A14.2Si 0.67 Tt-15~2Nb-3AI-0.2Si 0.62

?I-ISV~X~-~SP-~AI %s

25fhh=t

8.wW

250-0- CommacialtyRucn 7.70 Ti-15MdZI 7.70 Tb1!5hb3SS 5.37 T i - l W 5 C o 2.m n.is~0.0. i r 2.73 Ti-lSMPSRe 2.68 Ti.1SMO 2.63 Ti*lSMdFe 2.10 Ti. 1 SM0-3AI 2.00 Ti.lSMd).Zpd 1.79 TI-15Mo-O. 1Si 1 A5 Ti.15msHf 1.41 Ti- 1 JM0-0.2Si 1.27 Ti-lSMd).SSi 1.17 Ti-lsM0-3’Ig 1.04 Ti--2Nb a99 Ti-15Mo-zNb 0.98 Ti- 1 5MO-m a95 Ti.15Q-2Pd 9.76 Ti-15Cr-3Th 9.44 Ti- 15a-5Nb 762 T¶- 1 xlr.0JSi 7.00 Ti- 1 Xr-3Sn 4.11 Ti- 15G3Al 3.68 Ti. I Xr-SMo 2.90 Ti.1- 2-27

Note: Mtlrl oxidation resdtsfrom a 48herpo~urert815OC (1MIo “F) on 1.5 mm (0.02 in.) &ip ald rolled from 2S&g heat, 6.Zkg heat, and 2- buttam Source: WM. Parria nad PJ. Banin, %ta-218: A High Tempemturn Metaetable Beta lltaniumWoy,.TDAInt Conf.,Ohndo, lSa0

18

14 ? omdezn I /

0 2 4 6 0 10 12 14 16 HCI concentnuon, %

Beta-21s: Cormdon ra& m a lbnctioll d H C l coneentrrrtlon. Boiling HCI, 72-h test. Source: J.S. human, “ANew High S h n & Corrosion R c s i ~ T i - taniumAlloy,”TDAInt.Conf.,Orlrmdo, 1990

Beta41 5: Oeneml cormdon khavlor

-nag Medlum Rdrcrr 3% boiling H2S04 0.16 10% FeQ3. boiling 0.0 I 0.5% HQ, boiling 0.00254 1 % HCl, boiling O.oou)8

2% HQ, WE 0.0177s 2.5% HQ, Wiog 0.02794 f%HQ,bOiune 0.04064 4% HQ, boiling 0.127 10% HCl, bailing 4.0 15% HCI, boiling 15.0 28% Hcl. boiling, 55.0 10% fomdc acid 10% €a?&

acid, boiling, dcaeratcd

Note: Beta d mWaL hme: J.S.Orauman,‘ANewXigb Stmngth, CwmsionResbtrnt Imtpaiumm,”TDAInt. Cant., orkado, 1900

1.5% Ha W p 0.01016

0.0

378 ITlturlum Alloy FaUgw Da!a

Heat Capacity The specific W (CP, for beta-amraaled plus aged Beta-21S k-

tween 25 and 750 OC (77 and 1380 "p) (see figun) fits the expression:

Cp ( d g 6 'C) = 0.116 t 4.83 x lob (T)

Thermal Expansion The tbemral codficient of linear expansion (a) for beta-4nnealed

P~US WBete-2lS -25 and750 'C (77 and 1380 'F) (~fim) foLlows the eqeseion:

a(ppm/OC)=6.76+ 1 2 3 ~ 104T-2.27 x 104 9 + 1.s2 x 104 !la

Thermal Conductivity

for tieta-mded phis aged Beta-21 s (see figure) fits the eqllatim The therm41conductiVity betwem 25 and 750 O C (77 and 1380 "p)

Q (w/m* "c) = 7.33 t 1 . 6 8 ~ lo-' T

TIMETAL@ 21s I377

See also “Processing” for tensile data.

Although oxygen levels below 0.33 wt% do not appear to significantly affect the strength/ductilityrelationship,resultsoftests (see table) on sheet from two heats containing 0.14 and 0.25 wt% oxygen showed a

aged at 595 OC (1 100 OF). In the annealed condition, there is anotheref- fect of oxygen, which could be important in certain types of forming op-

erations. In the annealed condition, the difference betweenyield,dul!i- mate~strengthsdecreaseds~ox~levelirvreased6um42MW(6.1ksii at0.W oxygmt~-112MW(l.7Imiat0.33%axygen’Ihisbehaviar~ade

inaersemdre~toIlecklocanydfsilduingwtchingadmwingopem tiarrr

deleterious effect on ductility for the higher oxygen content in the series ~ m w a k h & a h g c a p b & y wihhx&ngoxygenandconanmartl ‘ y,m

Beta41 S RT tendle propertlea of sheet VI oxygen content

Aging temmtum wdne oxlVgen Ultimate tedh 8t-h Ilcdleyleld strength oc O F time, h content, % m M MPs ksi Ebnnotkn, %

NOne ... 0.14 880.5 127.7 8605 124.8 12.0 0.25 93 1 .5 135.1 914.3 132.6 15.0

480 895 4 0.14 1093.8 158.6 983.9 142.7 11.5 0.25 1011.5 146.7 975.0 141.4 14.0

8 0.14 1257.0 182.3 1145.3 166.1 4.0 0.25 1143.9 165.9 1114.9 161.7 5.0

16 0.14 1383.2 200.6 in6.9 185.2 5 .o 0.25 1473.5 213.7 13735 199.2 4 5

24 0.14 1428.6 207.2 1319.7 191.4 3 5 0.25 1529.3 221.8 1454.8 210.9 3.0

540 loo0 4 0.14 1297.0 188.1 1199.7 174.0 8.0 0.25 1381.8 m . 4 1297.6 188.2 5 5

8 0.14 1269.4 184.1 1185.3 171.9 5.0 0.25 1388.7 201.4 1303.2 169.0 3.5

16 0.14 1289.4 1m.o 1205.3 174.8 6.0 0.25 1409.3 204.4 1341.1 194.5 3.5

24 0.14 1268.0 183.9 1192.2 172.9 6.0 0.25 1388.7 201.4 1336.9 193.9 3.5

595 1100 4 0.14 1103.8 160.1 1024.6 148.6 11.0 0.25 1180.4 171.2 1108.7 160.8 6.0

8 0.14 1063.9 154.3 996.3 144.5 11.0 0.25 1172.2 170.0 1103.9 160.1 7 5

595 1 100 16 0.14 1074.2 155.8 999.8 145.0 10.0 0.25 1194.2 173.2 1128.7 163.7 5.0

24 0.14 1116.3 161.9 1059.1 153.6 8.0 0.25 1199.7 174.0 1128.7 163.7 6.5

Note Cold rolled 60% prior to annealing. 0.14% oxygen annealed at 816 “c (1600 OF), 6 min, AC; 0.26% oxygen annealed at 8157 ‘c (1610 OF), 6 min, AC. Prior to ten& testing, all sheet epecimene were deecaled and pickled to remove 0.06 mm (0.002 in.) h m each eurface to remow any material contaminated by argsen and/or nim duringheat treatment Teneileteeting waa carried out according to ASTM E8. Gage section forthe sheet specimens WBB 6 mm (0.26 in.) x 26 mm(1 in) and forthe bar specimen9 6 mm (0.26 in) diameter x 26 mm. Source: W.M. Parrie and P.J. Bania, ‘Oxygen Efikcts on the Mecharucal ’ Roperties of TIMETAL@ 215: 7th Int. Titanium W, July 1992

Beta-21 5: R l tenslle proprtles of sheet and bar v1 oxygen content

Simulated strlD(b) Fbt rolled bar UMmpteteflSUe Wkyiekl E b n p - Ulwmateteusile P d e y i e l d Redudbn Ebnga-

H a t oxygen, stn?ngth stmngth tbn, stmneth lltmgtb tbn, trertment(a) % M P P M M P n M % MPa bi htPa bi % % 8 4 5 T (1550°F), IOmin, AC 0.030 813.6 118.0 n i . 6 111.9 19.8 837.1 121.4 795.7 115.4 66.8 22.5

0.120 859.8 124.7 819.8 118.9 20.1 847.4 122.9 815.7 118.3 66.2 24.0 0.130 874.3 126.8 847.4 122.9 17.3 814.3 126.8 843.9 122.4 61.8 23.0

0.229(d) 930.8 135.0 912.9 132.4 17.4 899.1 130.4 890.1 129.1 66.1 27.0 0.334(e) 970.8 140.8 958.4 139.0 21.5 917.0 132.9 913.6 132.5 61.4 26.5

0.183(c) 900.5 130.6 888.8 128.9 18.4 882.6 128.1 853.6 123.8 63.6 23.3

8 4 5 T (1550°p), IOmin, 0.090 1336.9 193.9 12583 182.5 6.8 ... ... .( I . a . ..I I..

A c t 4 8 0 oC(900°px 14h, AC 0.120 1443.1 209.3 1341.8 194.6 4.1 1431.4 207.6 1352.1 196.1 15.8 7.0 0.130 1391.4 201.8 1306.6 189.5 3.0 1434.2 208.0 1346.6 195.3 15.9 6.5 0.183(c) 1447.3 209.9 1375.6 199.5 2.8 1494.8 216.8 1415.5 2053 125 4.5 0.229(d) 1541.7 223.6 1470.7 213.3 2.3 1583.1 229.6 1501.7 217.8 10.4 4.5 0.3We) 1579.6 229.1 1462.4 212.1 3.0 1540.3 223.4 1443.1 209.3 5.0 2.0

(continued)

378 I Titanium Alloy Fatlgue Data

BmQ1 S: R l tsnrllr pmpmias of shoot and k r VI oxygen content (COiItlnUd)

SimuhtedsMdb) Hotlvwbu U#lnlak tanJlc PMikyieid E b n p Ultlmatetemik 'KenrUcyWd Eeductbn Ekmp

d strength tb* stlww a f u s tba, Own, Q, MR-u M P a U % m Ll mksi % %

Hat tnrtmeeth) 845T (15U)OR. lOmh 0.090 1157.0 167.8 1024.6 148,6 9.6 12025 174.4 1037.0 150.4 47.6 10.9 Act540 oC(lo00 S 3 , 8 h , AC 0.120 1314.2 140.6 1232.8 178.8 5.8 1325.2 192.2 12535 1816 243 8.3

0.130 1320.4 191.5 1243.2 160.3 5.8 13266 192.4 1254.9 182.0 24.4 83 0.183(c) 1421.7 206.2 1319.7 191.4 1.4 1395.5 202.4 1329.5 1928 19.0 7.0 0.229(d) 1434.8 208.1 3377.6 199.8 4.3 1467.3 212.8 1388.0 201.3 19.2 7.8 0.334(c) 1461.1 211.9 1359.7 197.2 3.4 1425.2 206.7 1332.8 193.3 8.0 4.0

845°C (1550°F), 1Omi11, noso 937.0 135.9 8226 119.3 16.8 1045.3 151.6 947.4 137.4 44.2 115 AC+595 (llWDF), 8h, AC 0.120 1068.0 154.9 9866 143.0 12.5 11032 160.0 1010.1 1463 35.5 14.0

a130 1060.5 153.8 987.4 143.2 9.0 1099.8 159.5 10113 146.7 35.2 133 0.183(c) 1152.8 1672 1081.8 156.9 7.9 l1&6 169.2 1084.6 169.2 26.9 120 0.229(d) 1223.2 177.4 1148.0 166.5 8.0 1232.1 178.7 1146.6 166.3 225 103 0.33Yd) 1289.4 187.0 1194.2 173.2 6.5 1259.0 171.2 1180.4 171.2 16.0 8.3

(a)Annealingtima far ehsawae 10 min, forbar 1 h. (b) Cold mtled 60% prior to maling. (c)Anneded 867 "c. Id)Amealed 870 'C. [e)AIuIBaled 885 OC. Soum W M % aad P.J. Banin, "OxygenEfbets anthe bdechrnreal ' Propde30f"ME?FALQ21S," 7th Int. Titanium Conf., July 1992

-15: Typical room-trmperatun ag#d tensib propftbs

A&gtemwmtuda) pdt lblHiJGYi+lddlWldb Ukimatetrmlle ltrrnath Dc OF direction m Ld Mps hl 540 1MM L 1288 189 1353 196

L 1326 192 1394 202 T 1346 195 1422 206 T 1379 a00 1438 208 L 1 loo 159 1179 17 1 T I185 172 1243 180 T 1165 169 1240 179

Duplex@) ... 856 124 m 133 ... 840 122 914 132

(a)Amd8 h after beta anneal. (b) 8 hat 690 'c(U76 T),AC, + 660 'c (1200 T ) h 8 h,AC

EbnsltioD, % 9.0 7.5 6.5 7.0 11.0 11.0 10.0 18.0 20.0

~ ~ ~ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

%lldk?riddstmut b ulWmar tcluDc atmnh lcndkyh#rtrradh Uhlmrte~lledrenr(l rn w Mp. hi E l o l l e % MPa Ird Mps Lui moagatb&%

126 924 134 11.0 910 132 952 138 10.0 h- 869 869 126 896 130 9.0 903 131 93 1 135 9.0 834 121 862 125 120 876 127 910 132 10.0 855 124 876 127 12.0 889 129 910 132 10.0 869 126 8% 130 12.0 8% 130 931 135 10.0 869 126 8% 130 14.0 903 131 931 135 11.0 869 126 876 127 15.0 8% 130 903 131 12.0 876 l?l 883 128 12.0 903 131 910 132 120 903 13 1 952 138 11.0 945 137 1007 146 11.0 862 125 8% 130 136 903 131 938 136 11.0 855 124 8% 130 11.0 896 130 938 136 11.0 862 125 896 130 12.0 8% 130 924 134 11.0 924 134 952 138 10.0 965 140 993 144 10,0 938 136 986 143 14.0 972 141 1014 147 7.0 938 136 986 143 11.0 979 142 1027 149 8 .O %96 130 924 134 100 952 138 979 142 9.0

malrsvm

TIMETAL" 21s m

Beta-21s: Hlgh-temperature tsnslle pfopeftles (aged at 540 'C)

24 75 L

T T

205 400 L L T T

315 600 L L T T

425 800 L L T T

540 lo00 L L T T

1288 1326 1346 1379 1105 1096 1127 1154 1041 1019 1089 loso 976 969 1016 1m 576 614 616 648

187 192 195 200 160 159 163 167 151 147 158 152 141 140 147 145 83 97 89 94

1353 1394 1422 1438 1200 1204 1233 1249 1149 1156 1197 1158 1090 1077 1132 1122 838 849 867 886

1% un 24m 208 174 175 179 181 166 167 173 168 158 156 164 162 121 123 125 128

9.0 7.5 6.5 7.0 8.5 95 8.0 6.0 8.0 8.0 6.0 1.0 8.0 9.0 7.0 6.0 22.0 22.0 25.0 24.5

Temperature, O F

longatl 0 0 100 200 300 400 500 600

Temperature, OC

Beta-21s: High-temperature tensile properties. Beta annealed at 845 'C (1550 OF) for lOmin +540 "C (looO°F), 8 h

Beu-218: Hlgh-tempratun tensile pmpertles (aged at 540 'C)

llest ternmtum 'Rst I d l c y i d d d R n p t h Ultimate tanslie s t m n t h Ebmtbn, oc OF d M b n Mps bi MPa M % 24 75 L 1100 159 1179 17 1 11.0

T 1185 172 1243 180 11.0 T 1165 169 1240 179 10.0

205 400 L 893 129 1011 146 12.0 L 903 130 1020 148 10.0 T 907 131 1036 150 10.0 T 944 137 1069 155 10.0

315 600 L 832 121 955 138 10.0 L 830 120 969 140 10.0 T 861 125 1001 145 9.0 T 815 127 994 144 9.0

425 800 L n 6 112 909 132 10.0 L 807 117 925 134 10.0 T 818 118 946 137 9.0 T 856 124 967 140 7.0

540 loo0 L 598 86 741 107 26.9 L 587 85 751 109 24.0 T 613 69 773 112 28.5 T 633 92 822 119 12.0 L 598 86 74 1 107 26.9 L 587 85 75 1 109 24.0 T 613 89 773 112 285 T 633 92 822 119 12.0

380 I Titadurn Alloy Fatlgw Data

.... ....... ........ ........

i ............. ............

1

'I 13 14 1s 16 17 18

P- ( O c + 273)(20 i log moo0 Bda-ZfS Cmeprrrp1Bin STAnutairl. 1.5 mm(0.M in.) dmt;ttetaanne&d plus aged8 hat 540 OC (1UM "p)

973

97.1 6B.6 6ko 623 61.7 91.7 91.7

ma

b

1 10 AK W d m

14

TIMETAL@ 21s / 381

Formability. Limited fonning data indicate a similarity to Ti-ISV- 3Cr-3AI-3Sn (’Ti-15-3). In addition to tensile tests, some indication of sheet fonn-ability in annealed material was obtained by bend testing 25 mm (1 in.) wide strip. These specimens were bent 105’ around succes- sively smaller radii either until cracking visible at 2Ox magnification oc- cumd or until the minimum radius of 0,75 mm (0.030 in.) was reached. Sheet in the annealed condition from all heats sustained a 105” bend mund a 1.27 nun (0.050 in.) radius without cracking. This mslates to a bend ductility of 1 Tor less for sheet at all oxygen levels. Thus, oxygen contents up to 0.33% had no significant effect on this criterion for formability. However, as shown in the previous section on tensile properties, tensile data indicated a possible oxygen effect on other aspects of sheet fomability.

Machining, welding, and brazing of Beta-21 S is typical of beta al- loysandisconsideredsimilartothatof11-15-3. Heat Tmabmmt. In cases where high-temperature exposure is an-

ticipated, a duplex overage is used to retain ductility. The high tempera-

1500

0 0

0 to 20 30 40 50 Tlme, h

Beta-21s: lbnsikyhldstnngtb vsagingtima Betaarurealed 1.5 mm (0.06in.) sheet aged for indicated times and temperaturw

Forging Beta3lS can be fabricated into all forging product types, although

current closed die forging predominates. Beta-21s is a reasonably forge able alloy when forged above its beta transus, with higher unit pressures (flow stresses), improved forge-ability, and less crack sensitivity in forging than the a-@ alloy Ti-6A14V. Due to the high alloying content of Be&-21S, flow s m s e s are higher than those of the near-beta alloy Ti- 10V-2Fe-3Al. The desired final microstructure from thennomechanical pnrctssing of Beta-21s during forging manufacture is a fine transformed p, with limited grain boundary films and a fine, recrystallized prior p grain size in preparation for tinal thennal treatments.

Thermomechanical Pmcewing. The very fine microstructural features of Be.ta41S achieved in forgings are responsible for its excellent mechanical properties and fatigue resistance. Reheating for subsequent forging opaations recrystallizes the alloy from prior hot work, refining the grain size. Beta31S is generally not subtransus forged because there is no microsouctural advantage, and there is a sigrtificant increase in unit

Final thermal treatments for Beta-21s include a simple anneal (or solution anneal) for low-modulus applications or solution anneal and ag-

p fe s sy .

M age “wcskens” the grains relative to the grain boundaries and the second age stabilizes the grains against embrittlement. (See table and f i s u r e S J

0 10 20 3 0 4 0 5 0 lltna, h

W 2 1 S UltlmatetensiIe strength v8 aging time. Beta rrrmealed 1.5 mm (0.06 in.) sheet aged for indicatEd times and trmperanues

ing for higher strength Levels. Forgings may be supplied annealed, solution annealed, and/or fully aged (STA). Annealing or solution annealing generallyisconductedat815t0870°C (1500t.o 1600”F).Agingiscon- ductedat535to595OC(1000to llOOop),

Beta forging working histories for Beta-2lS require imparting enough hot worktoreach final macrostnrctureandmicroshucturcobjac- tives. Generally, reductions in any given forging pnxxss are 30 to 50% to achieve desired dynamic and static r e n y s t a l l i h y low levels of beta reduction are not recormnended. Hydrogen. Bcta-21S, as with all beta alloys, has a high aflinjty for

hydrogen. AlthoughBeta-2lSformskssacasefromheatingopaations than other alloy classes, thaefm raquiring less metal m v a l in chemical pickling (milling) pnxxsses, control of chemical removal processes is essential to preclude excessive hydrogen pickup.

Recommended forging rneEnl temperaturea range from 790 to

rized in ’Technical Note 4: Forging.” 850 O C (1450 to 1560 OF). R W O I Y U W U ~ ~ die temperacures SU~XIU-


Ti-5AI-2Sn-4Zr-4Mo-2Cr-1 Fe Beta-CEZ@ Compiled by Y. Combres, CEZUS Centre do Recherches, Ugine, France

Beta-Cl@ is a multifunctional near-p titanium alloy exhibiting high strength, hightoughness, and intermediate-temperecreep resistance. Its processing flexibility makes it suitable for a wide range of applications.

Product Forms and Conditions. Typical product forms consist of forged billets in diameters tanging from 1 SO to 300 mm (6 to 12 in.) and forged or rolled bar in diameters ranging from 10 up to 1 10 nun (0.4 to 4.3 in.). Rolled plate and sheet are also available in thicknesses ranging from 25 to 3 mm (1 to 0,l in.) and 500 mm (20 in.) wide. Roducts are supplied in the forged or solution treated conditions. The microstruchw is tine and equiaxed.

Applications. Typical applications include heavy section forgings used for medium-temperature compressor disks in which an optimum combination of strength, ductility, toughness, and creep resistance is requind. Beta-C- is a structural alloy with very high strength and a

good combination of strength, ductility, and toughness. Near-net shape forgings arc possible due to the excellent formability of the alloy. Com- ponent applications are as forged parts, springs, and fasteners.

Bota-CEf: Chemlcal compositbn

Crystal Structure. In the solution treated and aged condition, the microstructure consists of a + p phases. The lattice parameters of the close-packed hexagonal a phase are u = 2.9287 A and c = 4.6606 A, whereas the lattice parameter of the bodycentered cubic phase is u = 3.2040 A. Grain Structure. The microstructure is typical of p metastable al-

loys and may be p or a + p, either equiaxed or lamellar. Highest strength and ductility are achieved with an equiaxed primary a phase and a finely precipitated secondary a phase microstnrcn~e. Optimum toughness is obtained with lamellar primary a microsmchues.

'hnsformation Products. The continuous cooling (CCT) diagram is similar to that of Y-17. Alpha precipitation occurs first at grain

boundaries and secondly inside the grains. For instance, the time difference between grain boundary and inIragranular precipitation is about 1 h when cooled at 1 OC/min (1.8 Wmin) from the p field. The mansfma- tion of samples cooled from the p field exhibits a coarse a precipitation above 700 OC (1 290 "F) and fine acicular precipitation between 700 and 400 "C (1290 and 750 O F ) . A temperature of > 750 OC (1380 "F) is recommended for solution tnatments below the transus, whereas aging

Chemical Corrosion Resistance. Corrosion resistance in acid or seawater, as wet1 as hydrogen uptake and embrittlemmt are currently being studied. Data are not available yet.

treatmentsareperfonned&low700°c(1290~F)

Temperature, O F

50 150 2W 3W 450 660 860 750 850 950 Temperature, 'C

Beta-CEZ*: Thermsl eocfPldent Orli~~earexpansion w temperatwe

Tenslle Properties

Forged or rolled bars exhibit an cquiaxed microstructure, whereas .c .F O h l@ pri

mellar and ncckhcd microsrrucarres, nspectively. Beta-CEZ@ can 300 570 106 15

ortamellar~tnrctuns (see figure).

d: Young* rnoduk vrtmpamtun

-l- -%- Tensile Pmpaties depend strongly on microstrUcaue (see table).

processed and "through the fi transus" processed pancalres exbibit la- a0 68 122 17

meintain a high strength level at highteqmatms fbrbotb the quiaxd 400 750 100 14

150 mm (6 ia)dlmfagedkr huiogsa 830 OC(1525 Y), 1 h, WQ +S50 OC (1020 T), 8 h, AC

860 OC (1580 T), 1 h, WQ + 550 OC (1K20 T), 8 LAC 860OC(l58OT), lh,WQ+600OC(111OT),8h,AC

830 OC( IS25 T), 1 h, WQ + UOOC (1020 T), 8 8 A C 830 OC (1525 T), 1 h, WQ + 6 0 0 O C (1110 OF), 8LAC 860 OC (1580 T), 1 h, WQ + 5 5 0 O C (lo#) T), 8BAC 860 OC (1580 T), 1 h, WQ + 600 OC (1 110 TA 8 h, AC

2smm(lia)tfdckroIbdp~ ASuroueQL hurolbQT 83OOC(l525Tb lh,WQ+600OC(lllOT),8h,AC L 830OC(1525T), lh,WQ+600'C(lllOOF),8h,AC T 860OC(158093,1h,WQ+600OC(lllOOF),8h,AC L eaOOC(l58O'px lh,WQ+600OC(IllOT),84AC T 600 OC (1 110 T), 8 LAC 83OOC (1525 T), 1 h, WQ + 570OC (1060 'pX 8kAC 830 OC (1525 T), 1 h, WQ + 600 OC (1 110 T) ,8 h, AC 600 OC (1 110 T), 8 LAC 830 OC (1525 T), 1 h, WQ + 5MOC (1060 T) ,8 h, AC 830 OC(l525 OF), 1 h, WQ +600 "c (1 lIOoF), 8 h, AC

830 OC (1525 OF), 1 h, WQ +600OC (11 10 OF), 8h,AC

127 m(!$&.)btmM bar A8 rolbd

300m( l2 in)btm pprocsued plpalre

300 m ( 1 2 in) dirm "mrmgh me ~ " p l x u a e d

1040 1601 1283 1557

1490 1506 1373 1 m 1540 I222 1260 1334 1351 1405 1418 1608 1357 1326

1314 I263

1370

im

150 232 186 226 198 216 218 199 2s 223

182 193 1% m 205 233 197 192 178 190 183

in

%o 1518 laoB 1478 1301 1345 1460 1349 1683 14SS 1124 1163 1287 1300 1338 1340 1472 1171 1188 1138 la00 i im

139 zzo 175 214 189 1% 211 1% 244 215 163 168 186 188 194 194 213

172 165 174 169

im

18 2

11 2 5

11 13 ls 7 9

15 11 13 12 10 6 2 5 6

10 10 11


1 I O ST8SO"C

3,O 3,4 3.8 4.2 4.6 5.0 5.4 Log cycles to failure

3.0 3.4 3.8 4.2 4,6 6.0 Log cycles to failure

(8) @)

BetP-CEe: Low-cycle fbtigpe Porequiaxed microstrueturn aged at 6OOoC. (a) Specimens were from 150 mm (6 in.) dam forged bar. b) Beta-CEZ@: Low-cycle fatigue far lamellar and nscklaccd microsuuctuns after solurion tnating at 830 'C. (b) Necklaced mimsuucnrns were 80 mm (3.1 in.) dam "through the bawu8'' forged bar, lamellar mimtructures were 300 mm (12 in.) diam p-processed pancake.

Fatigue The alloy behaves v q well in low-cycle fatigue conditions between

20 OC (68 OF) (700 MPa, or 101 ksi) for 104 cycles) and 400 "C (750 OF) (600 MPa, or 87 ksi for 104 cycles). For high-cycle fatigue, equiaxed mi-

Crack Propagation Resistance Roducts with the best toughness exhibit good fatigue crack propa-

gation resistance at 20 "C (68 "p). Qpical &/dN characteristics are shown here.

Fracture Toughness Equiaxed microsmctures are characterized by toughness ranging

from 45 to 55 M P a 6 (40 to 50 k s i G ) . Toughness of the lamellar structure ranges from 60 to 90 M P a 6 (54 to 82 k s i g ) , whereas the necklaced microsuucture has a toughness ranging From 65 to 95 M P a G ( 5 9 to 86 ks iG)(see figure).

Low-temperature toughness usually ranges from 30 to 45 MPaG(27 to 41 k s i G ) at -253 "C (-423 OF).

BetaCp: Fatigue crack propagatton for lamellar or nocklweu mlorostructum

crospuctures have a fatigue limit of 900 MPa (130 ksi) for Id cycles at 20 OC (68 OF).

Yleld strength (0.2%), ksi 100 120 140 180 180 200

140 - 120 ' . ' " " - ' . ' - la-

" 0 800 lOa0 1200 1400

yle# strength (0.2%), MPa

Ma-CEZa: Fraetun toughness VB yidd strsnpta campolison. Specimens were 70 mm (2.7 in.) dim (1 + p rolled bar (equiaxed struchlre) and 80 mm 0.1 in.) d h ''thrcwgh the p trans^" forged bar (necklaced Stnrcture).

Forming Hot working in rhe a + range is recommended at 800 to 860 "C (1470 to 1580 O F ) to maintain a fine equiaxed micn>strucnrre. In the fl range, a temperature around 920 O C (1690 OF) is suggested to obtain a lamellar soUcture by @ processing.

'Through the ngllws" h e s i n g is a patented technique that results in a "necklaced" microstructure. It is applied to a loosb p metas-

Because the saain-rate sensitivity exponent ofBem.C@ is rather high compand to conventional alloys (0.3 for BetaCEZ" versus 0.2 for Ti-6Al-QV), plastic flow is more stable and enhances formability. The metastable nature of the alloy lowers its sensitivity to temperature.

WAIQSn4ZrSMo-2Cr-1 Fe BetaCEZ@/385

table structure below 890 OC (1635 OF'). Lamellae in the core of the grains and fine equiaxed grains at the boundaries are thus obtained, which leads to an excellent combination of strength, ductility, and toughness.

Superplastic Forming. The alloy displays superplastic properties between 725 and 775 OC (1340 and 1430 OF); 1000% ductility can be reached at strain rates as high as 8 x 10-4 sml. Diffusion bonding is being Studied.

Superplastic properties of Beta CEZ alloy are obtained at temperatures as low as 725 OC (Scripfa Met, Vol29, No. 4,1993, p 503-508). The as-forged material exhibits a complex microstructure, including the usual p and the globular primary alpha phases, but also a significant amount of acicular alpha. The superplastic behaviour of this unusual microstructure is associated with the breaking up of the acicular alpha in the first steps of deformation, which leads to a very fine mean grain size. The origin of superplasticity at these low temperatures is not yet clearly understood. More detailed investigations are needed, particularly to determine the effective diffusion coefficients in the phase, since slow and fast diffusing elements (in comparison to "I atoms) are present in this alloy.

I - E, 0.4 - 0.5 - E, 0.5 - 0.6 1 I 1

104 1 o4 104 10* Strain rate, s-'

Beta CEZ: Stmln-rate aemitivity at 760 "C. Deformation at 760 OC. Source: Scripta Met, Vol29, p 503-508

Heat Treatment Solution treatment is recommended between 750 and 860 O C

Aging is recommended between 525 and 65OOC (980 to 1200 OF)

Beta-cu@: Hardness kinaics for q u h x d m l c w m

ploduct

(1380 to 1580 OF') from 1 to 4 h. Aginstime, Hard-

Heat v), (30 kg), from 30 min to 8 h. As a function of aging time, the hardness evolves rap- lo,.,,, tRotmcDt min w idly (see table). Maximum hardness is about 560 HV. 150 mm (6 in.) As forged 0 345

diam forgedbar 860 OC (1580 OF), 2 h, WQ + 1 380 550 "C( 1ozO"F), I, AC 3 440

10 470 30 485

100 480 300 465

lo00 460 3ooo 460

Acknowledgments and Preface

ASM International would like to thank Robert Bucci (ALCOA), Glenn Nordrnark (ALCOA, retired), Ralph Stephens (University of Iowa, Mechanical Engineering), and Harold Margolin (Polytech- nic University, retired) fortheir assistance and advice in collecting information for this publication. This book also would not have been possible without the continued commitment by production at ASM In- ternational.

This ASM International publication should be a useful supplement toArlas of Fatigue Curves (ASM International, 1986) by providing more coverage of fatigue data for light structural alloys. Due to length restrictions, coverage of aluminum alloy fatigue was limited to stress-controlled (S-N) data.

S. Lampman

iii

List of Tables and Figures Aluminum Alloy Fatigue Data

Aluminum Alloy S-N htigue . 'Igbles

Summary of the 7050 plate materials used in the study of the

Comparison of the calculated material fatigue strengths and

meal tensile ptoperties and fatigue limit of aluminum alloys . . . . . 4

effect of microporosity on fatigue ......................... 9

improvements in open-hole fatigue for 7050plate materials .... 10 Hierarchy of fatigueinitiating features in 7050-T745 1 plate . . . . . . 10

Aluminum Alloy S-N Fatigue . Figures Comparison of fatigue strength bands for 2014.T6.2024-T4. and

Comparison of fatigue strength bands for 201 4-T6 aluminum

Plots of fatigue with static mechanical properties for 2014.2024.

Fatigue ratios (endurance limit/tensile strength) for aluminum

Relationships between the fatigue strength and tensile strength

Axial stress fatigue strength of 0.8 mm 2024.7075. and clad

Conpison of axial-stress fatigue strengths of 0.032 in.

Comparisons of fatigue lives of pressurized hydraulic cylinders

Cyclic stress intensity range. AK. vs . cyclic fatigue crack

Cumulative smooth fatigue lifetime distributors for oldquality

Cumulative smooth fatigue life distributions for newquality

Open-hole fatigue lifetimes for thin plate and 95% confidence

*hole fatigue lifetimes for newquality and

Open-hole fatigue lifetimes for low-porosity plate and 95%

7075-T6 aluminum alloys ............................... 3

alloy products ........................................ 3

and 7075 aluminum alloys ............................... 7

alloys and other materials ............................... 7

of some wrought aluminum alloys ........................ 8

shoetinairandseawater. R=O ........................... 8

aluminum alloy sheet in seawater and air ................... 9

in laboratory air and simulated seacoast environments at 80% designstress .......................................... 9

growthrate ........................................... 9

andnewqualityplate ................................... 9

and low-porosity thick plate ............................ 10

limitsfornewqualityplate.. ........................... 10

old-qualityplate ..................................... 10

confidence limits for newquality plate .................... 10

Aluminum Alloy S-N Data . 'ISblea Fatigue of W25% aluminum and various aluminum alloys ....... 13 Effect of cold work on aluminum fatigue ..................... 13 201 1 rotating beam fatigue (tempers T3 . T6. and T8 combined) com-

pared with upper and lower bands for 2014-T6 (notched and unnotched) ............................................ 14

2011 rotatingbeamfatigue ................................ 14

Aluminum Alloy S N Data . 'Ilables 2008-T4 and -T62: Room-temperature fatigue strength . . . . . . . . . . 13 201 1.T4 . .T6. and -T8: Roomtemperahue fatigue strength in air . . 14 2014-T6: Room- re fatiguestrengthinair.. ........... 16 2017-0 and -T4 Room-temperature fatigue strength in air ....... 17 2024-T3 sheet: Room-temperature fatigue strength in air ........ 18 2O24-T4: Room-tmpemlure fatigue strength in air . . . . . . . . . . . . . 21 2O24-T6 extruded rod: Rotating beam fatigue strength in air at

roomtemperature ..................................... 22 2024-T36. -T35 1 and -T361: Room-temperatun fatigue

smgthinair ........................................ 22

2024.T86. -T85 1. .T852. and -T861: Room-remperature fatigue strengthinair ........................................ 26

2025-T6 forging: Room-temperature fatigue strength in air. ...... 26 21 24-T35 1 and -T85 1 plate: Room-temperature fatigue

strengthinair ........................................ 26 2219: High-tempatm fatigue strength in air ................. 27 2219-T62: Roomtemperature fatigue strength in air ............ 28 2219-T87 plate: Room-tempenrture fatigue strength in air ........ 30

3004rod: Room.tcmpenuurefatiguestrengthinair ............. 36

5005-Hl4. .H18. -H19 Fatigue strength in air ................. 39 5050 Fatigue strength in air ............................... 39

2618-T6 and -T651: Room-temperanue fatigue stre@ in air ..... 33 3003: Roomtemperature fatigue strength in air ................ 34 5005-0 rod: Room-temperature fatigue strength in air ........... 38

5052.0. .H14. -H16. -H18: Fatigue strength in air .............. 39 5052-H32 and -H34: Fatigue strength in various environments . . . . 40 5052-H36: Room-temperature fatigue strength in air ............ 40

5082-Hll: Room-temperature fatigue strength in air ............ 43

5083-H112: Room-tempture fatigue sangth in air ........... 49

strengthinair ........................................ 49

5086-OFatiguestrengthinair ............................. 57

5086H112: Room-temperature fatigue saagth in air and water ... 57

5052-H38:Fatigue strength in air at various temperatures ......... 41 5056: Fatigue strength in air at various tanperahlres ............ 42

50834 Fatiguestrengthinair .............................. 44 5083-HI 1: Room-temperature fatigue strength ................ 45

5083.H31. .H32. and -H34: Room-temperatun fatigue

5083.H113.Fatiguesfrengthinair.. ........................ 52 5083-H321 and -H323: Room-tempwature fatigue sangth in air . . 54

5086-H111: Rwm-tempmature fatigue strengthinairand salt water ........................................... 57

5086-H32: Fatigue strength at various tempaatures in air andwater ........................................... 58

5 154-0: Fatigue strength in air .............................. 59

5 182-0 sheet: Room-temperature fatigue strength in air and saltsolution ......................................... 60

5356:Room-tempcrature fatigue strength in air ................ 60

545eH32:Fatigue strength in air ........................... 63 545447. .H11. and-H111: Room-temperature fatigue

5456-H32and -H321: Fatiguestrength ....................... 67

6009 sheet: Room-temperature fatigue sangth in various environments ........................................ 70

6010-T62 sheet: Room-temperature fatigue smngth in various environments .................................. 70

6013-T62 sheet: Room-temperature fatigue strength in variousenvironments., ................................ 70

606 1 : Room-temperature fatigue skrength in variousenvironments ................................. 76

6061-T6: Room-temperature fatigue strength in variws environments ........................................ 76

6063: Room-temperature facigue strength in air ................ 78 7002-T6 plate: Room-temperature fatigue strength in air ead

SevemRiverwatcr .................................... 79 7005: Room-mpcraturefatiguestrengthinair ................ 79 7039: Roomtemperature fatigue strength in air ................ 80 7050: Room-temperature fatigue strength in air ................ 90

5 154-H34:Fatigue strength in air at various temperatures ......... 59

5454: Room-temperature fatigue strength ..................... 62

strengthinair ........................................ 63 5456-H112 and -H3 11 :Room-tempmture fatigue strength ....... 67

5456-H343: Fatigue strength in air at low twnperatures .......... 69

6053-T6 wire: Umtched axial fatigue in room-temperature air . . . 71

7049-T73 forgings: Room-ternpetanre fatigue strength in air ..... 81

7075-0 . Room-tempmre fatigue strength m air .............. 93

388 / List of Tables end Flgures

70754 butt weld: Room-temperature fatigue strength in air . . . . . . 93

7075-T73: Room-temperature fatigue strength in air . . . . . . . . . . . . 95 7079-T6: Room-temperature fatigue strength in air and Severn

Riverwater ........................................ 102 7106-T63: Room-temperature fatigue sarngth in air and Severn

Riverwater ........................................ 102 7149T73: Room-temperature fatigue strength in air . . . . . . . . . . . 104 7175: Room-temperature fatigue strength in air . . . . . . . . . . . . . . . 105 7 178: Room-temperature fatigue strength in air ............... 109 7475 sheet and forging: Rwm-temperature fatigue

strength in air ...................................... 11 1 7475 plate: Room-temperature fatigue strength in air . . . . . . . . . . . 11 1 7475-T735 1 plate: Room-temperature fatigue strength in air

h m M L H D B K 5 . , ................................ 111 Cast aluminum alloys: Miscellaneous room-temperature

fatigue strength in air. ................................ 113

7075-T6: Room.temperaturefatiguestrengthinair. . . . . . . . . . . . . 94

Aluminum Alloy S-N Data . Figures Fatigue of 99.25% aluminum and various aluminum alloys . . . . . . . 13 Effect of cold work on aluminum fatiuge ..................... 13 201 1 rotating beam fatigue (tempers "3. T6. and T8 combined)

cornpad with upper and lower bands for 2014T6 (notched andunnotched) ...................................... 14

2011 rotating beam fatigue ................................ 14 Axial fatigue of 2014-T6 plate and 0 t h Al-alloy plate . . . . . . . . . . 15 2014-T6 notched rotating beam fatigue of (radius at notch

root4.001 in.). ..................................... 15 2014T6 unnotched axial fatigue ........................... 16 2014-T6modified~dmandiagram ....................... 16 201 7-T4 ~ ~ 0 t c h e . d rotating beam fatigue (plate and rod) . . . . . . . . 17 2V24-n modified Goodman diagram (bare and Alclad sheet) . . . . . 18 2024T4 modified Goodman diagram ....................... 19 2024-T4 notched axial fatigue (K, = 1 *6) from bar in longitudinal

direction ............................................ 19 2024-T4 notched axial fatigue (K, = 3.4) from bar in longitudinal

direction ............................................ 20 2 W T 4 notched rotating beam fatigue (K, = 2.1) for rolled, shot

peened (SP). and electrolytically polished (EP) specimens . . . . 20 2024-T4 unnotched axial fatigue (extruded bar) . . . . . . . . . . . . . . . . 2 1 2024-T4 rotating beam fatigue for unnotched and

notchedspecimens ................................... 21 2 U T 6 rotating beam fatigue for unnotched and

notchedspecimens ................................... 22 2024-T86 and 2024T4 rotating beam fatigue for unnotched

andnotchedspecimens ............................... 23 2024 rotatirg beam fatigue for unnotched and notched (Kf > 12)

specimens .......................................... 23 2024-T852 rotating beam fatigue for unnotched and notched speci-

mens ................................................ 23 2024T85 1 u~o tched axial fatigue at room temperature

(7/8 in . plate) ........................................ 24 2024T851 unnotcbed axial fatigue at 150 OC(300 OF)

(718 in . plate) ........................................ 24 2024-TM 1 notched axial fatigue (K1 = 4.4, r = 0.005 in.) at room temperature (718 in . plate) ......................... 25

2024-T851 notched axial fatigue (K, = 4.4, r = 0.005 in.) at 150 "C (300'F) ............................................ 25

2219-T8 unnotched axial fatigue at room temperature (plate. L,LT.S ............................................ 27

22 19-T8 notched axial fatigue (K, > 12) at mom temperature@late) .................................... 27

221 9-T8 rotating beam fatigue for unnotched and notchedspecimens ................................... 27

2219-T87 unnotched axial fatigue at room temperature (1 in . plate) .......................................... 28

2219-T87 notched axial fatigue (Kt = 4.4, r = 140.005 in.) at mom temperature ..................................... 29

2219-T87 unnotchedaxial fatigue at 150 "C (300 OF) (1 in. plate) . . 29 2219-T87 notched axial fatigue (Kf = 4.4, r = 0.005 in.)

at 15O0C(3oO0F) .................................... 30 22 19.T87 notched (radius at notch mot 4.001 in.) aad unnotched

rotating beamfatigue@late) ............................ 30 22 19-T85 1 unnotckl axial fatigue at mom temperahlre

(1 25in.p late) ....................................... 31 2219-Ts5 1 notched axhl fatigue (K, = 4.4, r = 0.005 in.) at room

2219-T851 unnotched axial fatigue at 150 "C (300 OF) (1.25in.plate) ....................................... 32

2219-T851 notchcdaxial fatigue (Kf= 4.4, t= 0.005 in.) at 150 OC (300°F) ............................................ 32

26 18-T65 1 unnotched axial fatigue at foom temperahue (1.35 in . plate) ....................................... 33

3003-Hl6 unnotched rotating beam fatigue at mom temperature (1and1/8in4rod) .................................... 34

3003-Hl8 notched and unnotched rotating beam fatigue at room temperature (0.75 in. rolled and drawn rod) . . . . . . . . . . . . 34

3003-H24 notched and unnotched rotating beam fatigue a! roomtemperaeure(0.75in.rolledanddrawnrod). ........... 34

3003-0 unnotched axial (R =-I) and rotating beam (R = -1) fatigue (0.75 in . diam rolled and drawn rod) ................ 34

3004-0 notched and unnotched rotating beam fatigue at room tempature (0.75 in . dim rod) ..................... 29

3004-H14 notched and unnotched rotating beam fatigue at mom temperature (0.75 in . rolled and drawn rod) ............ 29

3004-HI8 notched and unnotched rotating beam fatigue at mmtemperature(0.75in.dimrod) ..................... 29

3004-Hl9 notched and unnotched rotating beam fatigue at roomtemptun(0.75in.diamrod) ..................... 29

3004-H34 notched and unnotched rotating beam fatigue at room temperature (0. 7s in . dim rod) ..................... 36

3 W H 3 8 notched and unnotched rotating beam fatigue at room temperature (0.75 in . diam rolled and drawn rod) ........ 36

300Q-H39 notched and unnotched rotating beam fatigue at mom temperature (0.75 in . dim rod) ..................... 36

4032-T6 notched (K, > 12) and unnotched rotating beam fatigue for specimens ftom die forged pistons (fully forged and f q e d from cast preforms as indicated) ......................... 37

4032T6 unnotched rotating beam fatigue .................... 37 4043 unnotchcdmtating beam fatigue (0.75 in . diam rod) ........ 38 5052-H36 (52S-H36) unnotched axial fatigue at mom

5053-T6 (53S-T6) unnotched axial fatigue at mom tempentturc ... 41 5056-H32 and -H34 notched (radius at notch root 4.001 in.)

and unnotched rotating beam fatigue (34 in . rod. rolled anddrawn) .......................................... 42

5083-H11 rotating bending fatigue with machined notches

5083-H112 axial fatigue (R = -1) results for for double-strap butt welded channels with longitudinal fillet welds. 51 83 filler . . . . . 45

5083-H112 axial fatigue (R = 0) for doubIe-strap butt welded plate with longitudinal fillet welds. 5 183 filler . . . . . . . . . . . . . . 46

5083-H112 axial fatigue (R = 0) for double-strap butt weld with transverse fillet welds. 5183 filler ........................ 46

5083-H112 axial fatigue (R = 0) for double-strap butt welded channels with longitudinal fillet welds. 5183 filler ........... 47

5083-H112 constant life diagram (exmsions) ................. 47 5083 axial fatigue (R = 0) of sheet. plate. and exmsions ......... 48 5083 constant life diagram for butt welds (various tempers) . . . . . . . 48 5083-H 11 3 axial fatigue (R = 0) of plate with various surface

condido ns ........................................... 50 5083-H113 typical constant life diagram (sheet, plate) . . . . . . . . . . . 50

temperahue ......................................... 31

temperature ......................................... 40

and spiral scratches ................................... 44

List of Tables end Flgurw / 389

5083-H113 constant life diagram for butt welds (3/8 in., bead on, 5356filler) .......................................... 51

5083-8113 constant life diagram for butt welded plate . . . . . . . . . . 51 5083 and 5082 plane bending fatigue of longitudinal Nlet welded

beams .............................................. 52 508681 12 and H32 rotating beam fatigue ................... 55 5086-H32 typical constant life diagram of butt welded sheet . . . . . 55 5086 axial fatigue in longitudinal direction ................... 56 5086-H32 bending fatigue (R = -1) at high temperaaves . . . . . . . . . 56 53568321 notched (radius at notch root <0.001 in.) and unnotched

rotating beam fatigue at room temperature (314 in . plate) . . . . . . 60 5454-H34 notched (radius at notch root 4.001 in.) and unaotched

rotating beam fatigue at morn tempersture (plate and rolled- and-drawnrod) ...................................... 61

5454rotatingbeamfatigue inair and water . . . . . . . . . . . . . . . . . . . 61 5454-0 unnotched axial fatigue ............................ 62 54564321 unnotched axial fatigue compared with other alloys

(3/8 in . plate) ....................................... 64 5456-0 unnotched axial fatigue ............................ 64 5456-H 11 7 notcbed (K, = 3. r = 0.01 3 in.) and umotched axial

fatigue (R = 0) ....................................... 65 %56-H311 and-H321 rotatingbeamfatigueinairandwater . . . . . 65 5456H321 typical constant life diagram @late) ................ 66 54564321 typical constant life diagram butt welded plate ....... 66 5456-H343 axial fatigue (R = -1) at cryogenic temperatures ...... 69 6053-T6 unnotched axial fatigue at morn temperature. . . . . . . . . . . 71 6061-T6notched(radiusatnotchroot4.001 inJandunnotched

rotatingbeamfatigueatroomtemperature ................. 71 6061-T6 unnotched axial fatigue at mom temperatun . . . . . . . . . . . 71 6061-T6 (61S-T6)unnotched axial fatigue .................... 72 W l - T 6 rotating beam fatigue with residual stress . . . . . . . . . . . . . 72 6061-T6 rotating beam fatigue in air and water ................ 73 6061-T6 axial fatigue (R = 0) for double strap bua joint with

transverse fillet welds (4043 filler) ....................... 73 6061 -T6 axial fatigue (R = 0) for cruciform weld (4043 filler) ..... 74 6061-T6 axial fatigue (R = 0) for double strap butt joint with

longitudinalfilletwelds(4043fi~) ...................... 74 6061 -T6 axial fatigue (R = 0) with welded plate attachment

@arallel attachment, transverse met weld with 4043 filer) .... 75 6061-T6 axial fatigue (R = 0) with welded plate attachment

Qwpendicular attachmart. transverse fillet weld with 4043filler) .......................................... 75

6063-T42 notched (radius at notch root d.001 in.) and unnotched rotating beam fatigue at room tempnature (extruded rod, 3/4h . d h ) ......................................... 78

7002-T6 rotating beam fatigue compared with 7036-T64 and

703PT61 constant life diagram for butt weld (bead on, 5183fdler). ......................................... 80

7 W T 6 sheet unnotched axial fatigue at room temperature (0.125 in, sheet) ...................................... 81

7OST6 sheet notched axial fatigue (Kl = 3) at mom tempatwe . . 82 7050-T6 Alclad sheet unnotched axial fatigue at room temperature

(0.125in.sheet). ..................................... 82 7050-T6 Alclad sheet notched axial fatigue (K, = 3) at mom

temperature., ....................................... 83 7050-T7365 1 plate unnotched axial fatigue at m m temperatwe

(1 in.plate) .......................................... 83

transverse. morn t e m v r e ) ........................... 84

roomtemperature., ................................... 84

transverse. roomtemperame) ........................... 85

7106-T63., ......................................... 79

7050-T73652 hand forging UMOtChed axid fatigue (long

7050-"73651 plate notched axial fatigue (K, = 3) at

7050-"73652 hand forging unnotched axial fatigue (short

7050-773652 hand forging notched axial fatigue (XI = 3. long

705O-T73652 hand forging notched axial fatigue (K, = 3. transvase. mom temperature) ........................... 85

longitudinal. room temperature) ......................... 86

7050-T73652 hand forging notched axial fatigue (K. = 3. short transverse. room temperature) ........................... 86

7050-l73652 hand forging unnotched axial fatigue (longitudinal. momtemperature) .................................... 87

7050-7765 I1 extruded shape notched axial fatigue (K, = 3) at room temperature (longitudinal and long transverse) ......... 87

7050-T765 11 extruded shape unnotchsd axial fatigue Oonginulinatandlongtransverse) ........................ 88

7050-T6 axial fatigue (R = 0) compared with othrr alloys ........ 89 7075-T6 typical unnotched axial fatigue at room tempaature . . . . . 90 7075-T6 unnotcbed axial fatigue (various forms. longitudinal

direction) ........................................... 91 707S-T6 notched axial fatigue (K, = 1.6) longitudinal direction

(rolledbar) .......................................... 91 7075-T6 constant life diagram for notched (K, = 3.4) and

unnotchedspecimens ................................. 92 7075-T6 unnotched axial fatigue at mom temperature (sheet) ..... 92 7075-T6 notched (Kt = 1.5, notch-tip radius of 0.062 in.) axial

fatigue at mom temperam (rolled and drawn rod) ........... 93 7075-T73 notched (radius at notch root 4.001 in.) and

unnotched rotating beam fatigue at mom temperam ......... 95 7075-T65 10 short-transverse notched axial fa!igue (K, = 3) at

room temperature (extruded bar. 3.5 x7.5 in.) ............... 96 7075-T65 10 longitudinal notched axial fatigue (K, = 3) at room

temperature (extruded bar. 3.5 x 7.5 in.) ................... 96 7075-T65 10 longitudinal unnotched axial fatigue (extruded bar) ... 97 7075-T65 10 short-transverse unnotched axial fatigue

(exwdedbar) ........................................ w 7075-~351umotchedaxialfatigue(lin.plate) ............... 98 7075-T7351 notchedaxial fatigue (K, = 3) .................... 98 7075T735 10 longitudinal unnotched axial fatigue (extrusion) .... 99 7075-773510 short-transverse unnotched axial

fatigue(extrusion) .................................... 99 7075-735 10 longitudinal notched fatigue (K, = 3) Specimens

(extruded bar. 3.5 x7.5 in.) ............................ 100 7075-T735 10 short-transverse longitudinal notched fatigue

(Kl= 3) specinms(extrudedbar) ....................... 100 7075-T6 intergranular corrosion effect on fatigue (banding fatigue.

R=-1.0.125in.skt) ................................ 101 7075-T6 pitting corrosion effect on fatigue (bending fatigue,

R=-1,0,125in.~kt). ............................... 101 7075-T6 fatigue in air afkprecorrosion in 0.5 M NaCl at morn

temperature (mean stress 40 ksi 275 MPa) ................ 101 7075-T6 fatigue lives in 0.5 N NaCl solution . Mean stregs 7076-T6unnotChedaXialfatigucs~n ..................... 102 X7080-T7E42 uNlotched axial fatigue (extruded bar.

X7WT7E42 notched (Kr > 12) axial fatisue fatigue (extruded

707PT6 m s i o n fatigue (rotating cantilever beam. R = -1.

7175-7736 axial fatigue (R = 0) of p i s i o n a d conventional

7178-T651 unnotchedaxialfatigueatrcmmtempratum

717&T6510unnotchedaxial fatigueatmmtemperature

7178-T6510notchedaxialfatigue(K, =3)atroomtemperature

7 178-T65 10 notched axial fatigue (Kt = 3) at room tmpcrature

7178-T6510notchedaxialfatigue(Kt> 12) atroom mpuature

7 178-T65 10 notched axial fatigue (Kt > 12) at mom temperaaue (3.5x7.5in. extrudedbar) ............................. 109

7475.T651.-T7351.and -77651 unnotchcdaxialfatigue@late) . . 110

40 h i (275 M a ) .................................... 101

3.5x7.5in.) ........................................ 103

bar. 3.5 x7.5 in.) ..................................... 103

roomtemperature). .................................. 104

forgings ........................................... 105

(1-3/8in.plate). ..................................... 106

717&T6 unnotched axial fatigue at room temperatun .......... 107

(3.5 x7.5in,exeudedbar) ............................. 107

(1-3/8h.plate) ..................................... 108

(1-3/8in. plate) ..................................... 108

(3.5 x7.5 in.extrudedbar) ............................. 106

390 / Ust of Tablee and Figures

7475-"7351 notched axial fatigue (Kt = 3. notch radius

Sc-ds for rotating beam (R = -1) fatigue strength of

Scambands for rotating beam (R = -1) fatigue strength of sand

of0.013h,), ....................................... 110

permanentmoldaluminurncastingalloys . . . . . . . . . . . . . . . . . 112

1 13 cast aluminum alloys ................................

Magnesium Alloy Fatigue Data

Magesium Alloy Fatigue and Fracture . 'Igbles Selection of magnesium alloy components in new production

Nominal composition. typical tensile properties. and characteristics

Representative mechanical properties of magnesium alloys . . . . . . 124 Minimum tensile properties ftom designated areas of

Mechanical Properties of permanent mold castings . . . . . . . . . . . . 125 Cast magnesium alloy fatigue strength Nominal composition. typical tensile propefiies. and

Wrought magnesium alloy fatigue strength Typical room-temperature mechanical properties of EA55RS

extrusions .......................................... 138 Qpical toughness of magnesium alloys ..................... 141 Fracture toughness of various alloys ........................ 142 Comparison of mean values of Jc for various specimen geometries

anddoys .......................................... 142 Composition and mechanical properties of two

magnesium alloys ................................... 143

motorcarsandtrucks ................................. 117

of selected magnesium casting alloys

sandcastings ....................................... 124

characteristics of selected wrought magnesium alloys . . . . . . . 13 1

Magesium Alloy Fatigue and Fracture . Figurea Atomic diameters of the elements and the favorable size factor

(shaded area) with respect to magnesium . . . . . . . . . . . . . . . . . 118 Probable precipitation processes in magnesium alloys. . . . . . . . . . 119 Stress for 0.1% creep strain in 100 h for cast alloys based on

the Mg-A1 system and for the aluminum casting alloy A380 . . . 122 Effect of the addition of copper on the morphology of the eutectic

foralloy MgdZn .................................... 122 Effect of exposure at 250 OC on 0.2% yield strength at mom

tunpramre for several cast magnesium alloys containing rare earth elements. .................................. 122

Fatigue suength of magnesium alloys at room temperature . . . . . . I25 Effect of surface type on the fatigue properties of cast magnesium-

aluminum-zinc alloys ................................ 130 Effect of temperature on the fatigue endurance of some

magnesium casting alloys ............................. 130 Rotating bending fatigue properties of EA55RS at 2800 Hz . . . . . 139 E W of heat treatment on fracture mechanic properties of

rapidly solidifiedmagnesiumalloys ..................... 139 Rotating bending fatigue strength vs . ultimate tensile strength

of magnesium alloys (small smooth specimens) . . . . . . . . . . . . 140 Fatigue properties of A357. AZ91E. and WE43 . R = 0.1 . . . . . . . . 140 Effect of stress ratio and notches on fatigue of two

magnesiumalloys ................................... 140 E M of specimen size on fatigue smngth of magnesium alloys

(smooth. rotating bending specimens) .................... 141 Variation of apparent fracture toughness (KIE) with crack size . . . . 142 Crack growth rate curves for several metals compared on the

basis of driving force normalized by modulus . . . . . . . . . . . . . . 143 Comparison of crack propagation curve8 .................... 143 AK vs . WdN at R = 0.5 for two magnesium alloys . . . . . . . . . . . . . 143 Corrosion-fatigue crack growth curves for ZK60A-T5 in

differeat environments ................................ 144

Data comparing similar cast and wrought magnesium alloys

Stress vs . time-to-failure (k) for magnesium-aluminum alloys in

Stnss corrosion of sandcast AZ91C (T4 and T6) in

Stress vs . time-to-failure (tf) for the two-phase alloys Az80 (Mg-8.5N-O,5Zn) and A261 (Mg-6Al-lZn) in aqueous 40g/LNaClt40g/LNa2CrOq ......................... 146

Stress-comsion resistance for AZ31B sheet in rival annosphere . . 146 llme-to-failure for Awl (Mg3Al-lZn) magnesium alloy

exposed in a 3.5% NaCl + 2%K$Q aqueous solution at30"C ............................................ 147

Stress comwion of ZK60A-T5 extiusion in rural atmosphere . . . . . 147 Fatigue behavior comparison of coated and uncoated magnesium

alloy specimens at mom tempture ..................... 147 Fatigue of commercial pure 9980Amagnesium (UNS M19980)

inairandinvacuum .................................. 147

during long-term stressanrodon cracking (SCC) .......... 145

aqueous 40 g/L NaCl t 40 g/L Na2Cr0 4.. . . . . . . . . . . . . . . . . . 145

ruralatmosphere. .................................... 145

Magnesium Alloy Fatigue Data -Tables

Mg-A1 Casting Alloys AM100A: Rotating bending. R = -1 fatigue strength for

permanent mold castings .............................. 151 AZ63A: Fatigueseengthof sandcasttest bars ................ 151 AZ91C: Beding fatigue of cast specimens .................. 153 AZ91C: Rotating ticam fatigue strength ..................... 153 AZ92A: Fatigue of sandcastings .......................... 156 AZ92A: Fatigue of notched sand castings .................... 156

Fatigue strengthsofAZ31B-Fexwsions . . .................. 157 Effect of corrosion on fatigue properties of AZ3 1 B (Axial losd;

R=O.W), .......................................... 158 Fatigue strength of AZ6l A forgings ........................ 159 Fatigue strength of AZ61A-Fextrusions ..................... 159 Fatigue strength of AZ80A-F extiusions ..................... 160 Fatigue strengthof AZ80A ............................... 161 Fatigue strength of notched AZ80A ........................ 161 FatigueofAZSlAforgings ............................... 162

Mg-Zn Alloys W62AandZK61Afatigue strength compilation .............. 164 Fatigue strength of forged ZK60A wheel rims ................ 166 R=O.ldata ........................................... 167 R=0.4data ........................................... 167 R=0.7da&. .......................................... 168 Lkyargondata.R=O. ................................... 169 Distilledwaterdata, R=O ................................ 169

Mg-Th Alloys Magnesium-thorium alloys: Miscellaneous fatigue strength data . . 170 Fatigue Properties of HM21A-TS forgings . . . . . . . . . . . . . . . . . . . 171

Miscellaneous Mg Alloys Magnesium-silver alloys: fatigue strength at room temperature ... 173 QE22Acwkgrowthdata(R=O). ......................... 174 Fatigue strength of EZ33A ............................... 175 Rotating beam (R = -1) fatigue strength of M1A-F extrusions .... 177 MlA(AM503)crackgrowthdata .......................... 177 GA3Zl:Plasticandelasticfatigue panuneters ................ 178 Chemical composition of some wrought Russian magnesium

alloys. wt% ......................................... 178

List of Tables and Figures / 391

Magnesium Alloy Fatigue Data . Figures

Mg-A1 Casting Alloys AZ63A-T4: S-N curve for cast and notched specimens . . . . . . . . . 152 AZ91B: Axial fatigue of die cast bar ........................ 152 AZ91B: Rotating beam fatigue of die cast bar . . . . . . . . . . . . . . . . 152 AZ91B: Plate bending fatigue of die cast bar . . . . . . . . . . . . . . . . . 153 AZ91C-T6: Strain-life diagram for cast specimens . . . . . . . . . . . . 154 AZ91D-HP Strain-lifediagram ........................... 154 AZ91ET6: Lowcycle fatigue ............................ 154 AZ91ET6: Fatigue crack growth behavior .................. 155 AZ91ET6: Lowcycle fatigue in salt-water solution ........... 155 AZ91E: Fatigue crack growth behavior in salt water solution . . . . 155

Mg-A1 Wrought Alloys Cantilever bending fatigue of AZ3 1 B-H24 plate . . . . . . . . . . . . . . 157 Bending fatigue of AZ3 1 B-H24 sheet. ...................... 157 Strain-life diagram for AZ3 1 B ............................ 158 da/dN data for AZ3 1 B magnesium (H24) .................... 159 S-N a w e s for AZ61A bar ................................ 160 S-N curves forAZ61Aplate .............................. 160 High stress fatigue of AZ80 magnesium alloy . . . . . . . . . . . . . . . . 162 High stress fatigue of AZ80 magnesium alloy . . . . . . . . . . . . . . . . 162

Mg-Zn Alloys Fatigue properties of ZE41A. notched and unnotched . . . . . . . . . . 163 Rotating beam fatigue strength of ZK6 1 A . . . . . . . . . . . . . . . . . . . 163 Fatigue of ZElOA sheet .................................. 164 ZK60A (F temper): rotating beam fatigue (R = -1) . . . . . . . . . . . . . 165 ZK60A (T5 temper): rotating beam fatigue (R = -1) . . . . . . . . . . . . 165 ZK60A (F temper) extrusions: axial fatigue (R = 0.25). . . . . . . . . . 165 ZK60A fl5 temper) extrusions: axial fatigue (R = 0.25) . . . . . . . . 165 Rotating beam fatigue strength of ZK60A-T5 forgings . . . . . . . . . 166 Flexure fatigue of ZK60A-T5 forgings ...................... 166 U d N data for ZK60A.TS ................................ 167 MdN data for ZK60A magnesium ......................... 168

Mg-Th Alloys Room temperalure and axial fatigue of HK3 1A . . . . . . . . . . . . . . . 170 Axial fatigue ofHK31Aat 260 "C (500 OF) . . . . . . . . . . . . . . . . . . 170 AxialfatigueofHK31Aat 15OoC(300"F) . . . . . . . . . . . . . . . . . . 170

171 Fatigue of HM21 A in air and vacuum. ...................... 171 Fatigue of HM21 A sheet ................................. 172 Rotating beam fatigue of HM3 1A .......................... 172

The effect of temperature on the fatigue strength of HZ32A . . . . .

Miscellaneous Alloys Notched fatigue strength of QH21 ......................... 173 Fatigue strength of QE22A at high temperature . . . . . . . . . . . . . . . 174 Fatigue crack growth of QE22A magnesium ................. 174 Fatigue strength of EZ33A at mom temperature . . . . . . . . . . . . . . . 175 Fatigue strength of EZ33A at 200 OC ....................... 175 Fatigue strength of EZ33A a! 260 "C ....................... 175 Fatigue crack growth of EZ33A-T5 magnesium ............... 176 Fatigue of LA141A in air and vacuum ...................... 176 Fatigue of LA141A with various coatings . . . . . . . . . . . . . . . . . . . 176 da/dN data for AM503 magnesium ......................... 177 Plastic strain life of GA3Zl .............................. 178 Fatigue crack growth me curves for magnesium alloys at

roomtemperatureand-135Ik ......................... 161 Fatigue crack growth rate for magnesium alloys . . . . . . . . . . . . . . . 161 Fatigue crack growth rate data for MA12 in different

structuralstates ..................................... 161

A comparison of fatigue crack growth rate curves for different partsofanMA15 weldjoint ............................ 161

Titanium Alloy Fatigue Data

Titanium Alloys Fatigue and Fracture . 'i8bles Beta stabilizing elements ................................. 188 Beta alloys of current interest ............................. 188 Typical mill-guaranteed mom tempahm tensile properties

for selected titanium alloys ............................ 189 Fraction of room-temperature strength retained at elevated

tempenhue for several titanium alloys(a) ................. 189 Typical specifications for titanium and titanium alloys . . . . . . . . . . 190 Typical fracture toughness of high-strength titanium alloys ...... 190 Effect of hydrogen content on room-temperature Klc in alloy

TidAI-4V after f u m e cooling from 927 OC (1700 OF) ...... 190 Relationship between Klc and fraction of transformed structure

in alloy Ti-6A1-4V ................................... 190 Effect of primary alpha dispersion on Klc for alloy

Ti4Al-2Sn-4Mo-O.SSi (IMI550) plate(a) ................. 191 Effect of forging procedure on fracture toughness of alloy

Ti.6A1-2Sn-4Zr-6Mo ................................. 191 Fracture toughness of alloy Ti-6AMV (0.11 wt% OJ in welds

and heat affected zones ............................... 191 Effect of test direction on mechanical properties of textured

Selected data on effect of alloy type on fatigue crack propagation resistance in room temperature air at 0.6 Hz ............... 193

Effect of oxygen on fatigue crack propagation in room temperature air for Ti-6Al.4V. RAor FA/DB(a). plate at R = 0.3 and fhquencies of 1 to 6 Hz(b) ............................. 194

Tensile properties of equiaxed a+ Ti-Mn alloys .............. 195 Qpical mechanical properties of selected beta alloys . . . . . . . . . . . 199

Ti-6Al-2Sn-4Zr-6Mo plate ............................ 192

Titanium Alloys Fatigue and Fracture . Figures Typical microstructures of alloy Ti-6A1-4V .................. 184 Microstructure of alloy "l-6A1-4V after

recrystallization annealing ............................. 185 Distorted WidmansWen alpha remaining as a result of limited

working in the a+j3 field .............................. 185 Grain boundary alpha remnants which were not broken up after

Illustration of quenching rate effect on microstructures of alloy

Plot of elastic modulus vs direction in single crystal of titanium

Mluence of oxygen content on fracture toughness of

Variation of fatigue crack propagation rate with yield strength.

Nustration of the scatter that can occur in fatigue crack

Effect of heat treatment on fatigue crack growth rate of alloy

Crack propagation data for the 3.9 Mn alloy in the LT and

MAN as a function of AK/YS (yield strength) for the 0.4,2.0,

Schematic illustration of MuW-AK curve behavior as a function

Dependence. of FCP in j3 forged Ti-6A1-4V pancake forging on

Dependence of FCP in a+ forged Ti-6A14V pancake forging

forging ............................................ 185

TidAl-4V ......................................... 186

for various temperatures .............................. 187

recrystallization annealed alloy Ti-6A1-4V . . . . . . . . . . . . . . . . 190

Klc and other variables for annealed Ti-6A14V forgings ...... 193

propagation measurements ............................ 193

Ti-6A1-4V ......................................... 194

T L d W o n s ....................................... 195

3.9,5.6,8.O,andlO.OMnalloysfortheTLdirection ........ 195

of increasing R in titanium alloys ........................ 196

gaseous environment. ................................ 197

on gaseous environment ............................... 197

392 / List of Tables and Figures

Ti3AD.W . Figures T1-3A1-2.5V: Smooth and notched bending fatigue ............. 219 Ti-3A1-2.5V Fatigue of plate and GTA weld metal . . . . . . . . . . . . . 219 Ti-3Al-2.5V Bending fatigue strength of annealed sheef . . . . . . . 220 Ti-3AI-2.W Fatigue strength of annealed tubing . . . . . . . . . . . . . . 220 Ti-3A1-2.5V Effect of tube reductions on texture and Propertieas, . 222 Ti-3A1-2SV Effect of texture on tensile properties . . . . . . . . . . . . 222

Effect of environment on fatigue crack growth rates at R = 0.1 in recrystallization annealed alloy "i-6A14V (1 Hz) . . I . . I

Effect of environment on fatigue crack growth rates at R = 0.50

Sustained load crack growth behavior of alloy TMA14V in twoenvironments ..................................

Effect of microstructure and temperature on sustained load crack propagation in 'K-6A1-4V in 3.5% NaCl solution . . . . . . . . . .

in recrystallization annealed alloy Ti-6Al4V (0.1 Hz) . . . . . . . 197

. 197

. 198

I 198 S&& &d notched axial fatigue data Ti-lOV-2Fe3AI precision

and conventional forgings ............................. 199 Strain controlled. low-cycle fatigue dataTi-lOV-2Fe-3Al

forgings. processed to intennediate strength levels . . . . . . . . . . 200 Fatigue crack growth rate data . Ti-IOV-2Fe-3Al forgings . . . . . . . 200

Titanium Fatigue Data

Commercially Pure and Modified Titanium . Tables

Unalloyed titanium grade 1 and equivalents: Specifications andcompositions., .................................. 205

Unalloyed titanium grade 1 compositions: Producerspecifications ............................... 206

Unalloyed titanium grade 2 and equivalents: Specifications andcompositions ................................... 207

Unalloyed titanium @ 2 compositions: Roducerspecifications ............................... 209

Unalloyed titanium grade 3 and equivalents: Specifications andcompositions ................................... 209

Unalloyed titanium p& 3 compositions: Producer specifications ............................... 21 0

Unalloyed titanium grade 4 and equivalents: Specifications andcompositions .................................... 211

Unalloyed titanium grade 4 commercial equivalents: Compositions ....................................... 212

Ti-O.2Pd p & s 7 and 11 and equivalents: Specifications andcompositions .................................... 212

Ti-0.2Pd grades 7 and 11 compositions: Producer specifications . . 2 13 ASTM grade 4: RTrotating and axial fatigue . . . . . . . . . . . . . . . . . 2 15 ASTM grade 3: Reverse bending fatigue .................... 2 15 CPTi: Fracture toughness in air and 3.5% NaCl eolution

at25"C ........................................... 216 CPTk Charpy V-notch impact toughness. . . . . . . . . . . . . . . . . . . . 216

Commercially Pure and Modifled Titanium . FIgures CP Ti: Fatigue strength at 10' cycles ........................ 2 15 Low-irongmde2Ti:Fatigueat15OoC., .................... 215 ASTM grade 3 Ti: RTrotating beam fatigue strength . . . . . . . . . . . 216 ASTM grade 4 Ti: Rotating-beam fatigue strength . . . . . . . . . . . . . 2 16 CPm: Charpy V-notch impact toughness vs yield strength . . . . . . . 216 CPTi: Charpy V-notch impact toughness vs temperature . . . . . . . . 21 7 CPTi: Fracture mechanisms ploaed by stress and tempetature . . . 2 17

Ti3Al2.S'- ' b b b

Ti-3A1-2.5V Specifications and compositions. . . . . . . . . . . . . . . . 218 Ti-3A1-2.5V Charpy V-notch impact strtngth of extruded plate

andwelds .......................................... 221 TI-3AI-2.5V Charpy V-notch impact suength of 25 mm (1 in.)

exmdedplate ...................................... 221 Ti-3A1-2.5V Sustained load cracking of heat treated plate

inseewater ......................................... 221 Ti-3Al-2.5V: Fracture toughness of extrusions in several

heat treated conditions compared to weld metal . . . . . . . . . . . . 221 Ti-3A1-2.5V Tensile properties of tubing .................... 223 Seamless tubing comparison .............................. 223

TMAl-25Sn . Tsbles Ti-SA1-2.5Sn: Specifications and compositions ............... 224 "i-SAl-2.5Sn: Compositions .............................. 225 Ti-SA1-2.5Sn: Low-temperature fatigue life of welded sheet ..... 227 Ti-SA1-2.5Sn: Fatigue crack growth of annealed stteet at

roomtemperature .................................... 227 Ti-SAl-2.5Sn: Fatigue crack growth rate compared to

Ti-6AI4V ......................................... 228 Ti.5A1.2. 5Sn. Fracture toughness .......................... 229 Ti-SA1-2.5Sn: Comparison of fracture toughness of two

titanium alloys ...................................... 229 Ti-SA1-2.5Sn (ELI): Fracture toughness of 13 mm

(0.50 in.) thick plate .................................. 230 Ti-SA1-2.5Sn: Fracture toughness of 13 mm (0.5 in) thick plate. .. 230 Ti-SA1-2.5Sn (ELI): Fracture toughness of 6.4 mm (0.25 in.)

thickplate .......................................... 231 Ti-SA1-2.5Sn (ELI>: Fracture toughness of 25 mm (1 in.)

thick plate .......................................... 231

Ti-5A1-25Sn . Figures Ti-SA1-2.5Sn: Fatigue endurance ratio comparisoh ........... 225 Ti-SAI-2.5Sn: Rotating-beam fatigue strength. ............... 225 Ti-SA1-2.5Sn: Rotating-beam fatigue strength ............... 226 Ti-5A1-2.5Sn: Rotating-beam fatigue strength . . . . . . . . . . . . . . . . 226 Ti-SAi-2.5Sn: Constant life diagram of mill annealed sheet. . . . . . 226 Ti-SAl-2.5Sn ELI: Fatigue strength w temperature . . . . . . . . . . . . 227 Ti-SA1-2.5Sn ELI Crack growth at mrn temperature . . . . . . . . . . 228 Ti-SA1-2.5Sn: Fatigue crack growth rates .................... 228 TI-SA1-2.5Sn: Fracture mechanism map ..................... 228 T1-5A1-2.5Sn: Timato.fracture ............................ 228 Ti-SAI-2.5Sn: Fracture toughness plate ...................... 230 Ti-SAl-2.SSn: Fracturetoughnessplate ...................... 230 Ti-SA1-2.5Sn ELI: Fracture strength of cracked cylinders . . . . . . . 231 Ti-SA1-2.5Sn ELI Fracture toughness at several temperatures . . . . 231

TidAI-2Sn-42~2Md).OSSi . 'Igblee Ti-6Al-2Sn4Zr-2Mo-O.08Si: Specifications

andcompositions ................................... 232 Ti-6AI-2Sn-4Zr-2Mo-0.08Si : Compositions . . . . . . . . . . . . . . . . . 233 TI-6242: Effect of heat treatment on RT impact toughness of

castspecimens ...................................... 236 TI-6242: Fracture toughness of forgings ..................... 237 TI-6242s: Fracture toughness of forgings from various

thennomechanical processing (TMP) routes ............... 237 Ti-6242: Fracture toughness of duplex annealed bar . . . . . . . . . . . . 237

TidA1-2Sn-4Zr-2W.0Si . Figures Ti-6242: RT fatigue properties ............................ 233 Ti.6242.Fatiguepropertiesat205'C. ...................... 233 Ti-6242: Fatigue properties at 425 OC ....................... 234 Ti-6242: RT and 480 l?C fatigue properties . . . . . . . . . . . . . . . . . . 234 Ti-6242: Fatigue properties at 480 'C ....................... 234 TI-6242:Fatiguestre11gthat315and480'C . . . . . . . . . . . . . . . . . 235 Ti-6242: High-frequency fatigue properties .................. 235 Ti-6242: Fatigue strength at 200 'C ........................ 235 Ti-6242: Fatigue strength at 455 OC ........................ 235

Lirt of T a m and Figurer / 393

Ti-6242: Impact toughness vs silicon content at 4 0 O C ........ 236 Ti-6242: EfFect of oxygen on cast impact toughness ........... 236 TI-6242:Fractureto~ghnessofpLte ....................... 237

Ti-BAI-lMa-lV . l h b k Ti-8Al-lMo-lV Specifications and compositions ............. 238 TI-8Al-IMo-lV Commercial compositions .................. 239 Ti-8Al-1Mo-IV "ypicalmtatingbeamfatigueof

rolledbarstock ...................................... 239

Ti-8AI-1Mo-IVFatiguenackgrowthdata . . . . . . . . . . . . . . . . . . 240 Ti-8Al-IMo-IV Effects of rolling temperature on Charpy

impact toughs .................................... 244

TestWnditionsforbest-fitS/"uWes ...................... 239

Test ~ n d i t i o n ~ for best-fit SN CWCS ....................... 241

TI-8Al-1Mo-IV Typical toughness at room temperature . . . . . . . . 245

'If-8Al-IMo-lV Effect of heat treatment on impact toughness . . . 246 Tl-8Al-lM0-lV Plane-stress toughneSS-(K& . . . . . . . . . . . . . . . . 246

Ti-8Al-lMo-lV . F'@w

Ti-8AI-lMo-IV Best-fit S/N curves for unnotched sheet at RT . . 239 Ti-8Al-IMo-1V Best-fit S/N c w e s at 200 OC ............... 240 Ti-8AI-IMo-lV Best-fit S/N curves at 345 OC ............... 240 Ti-8AI-IMo-lV Best-fit S/N curves for notched shea at RT .... 241

Ti-8AI-1Mo-1V Best-fit S/N curves at 345 OC ............... 241 Ti-8Al-IMo-1V Notched fatigue at low temperanues ......... 241 Ti-8Al-1Mo-IV Axialloadsharp notch fatigue .............. 241 Ti-8Al-IMo-1VFatigueinsalt solution ..................... 242 Ti-8Al-IMo-1V Crack growth in fan blade specimens ......... 242 Ti-8Al-IMo-lV Crackgrowthvsenvironment ............... 243

Ti-8Al-lMo-lV Microstrum and m s i o n fatigue ......... 243 TE-8Al-IMo-lV Effects of frequency in a stressarmsion-

inducing environment ................................ 24.4 Ti-8AI-IMo- 1 V Effect of frequency on d a a vs AK . . . . . . . . . . 244 Ti-8AI-IMo-IV Stress-conosion susceptibility .............. 245 Ti-8AI-1 Mo-1 V SCC resistance for bending or torsion . . . . . . . . 245 Ti-8AI-1 Mo- 1 V Time to failure compared to Ti-6A1-4V

at24OC ........................................... 245 Ti-8A1-1 Mo-1V KR. KM. and K b vs hydrogen . . . . . . . . . . . . . 245

Ti-8AI-IMo-lV Best-fit S/N C W ~ S at 2 0 0 T ............... 241

T 1 - 8 A I - I M o - I V : C r a c k ~ w t h ~ ~ C P t i ~ a n i ~ . . . . . . . . . . . . . . . 243

TIMETAL@ 1100 . 'hbles Ti.l100:.icalcornpositionrange ........................ 247 "I-1 100: Summary of typical physical propertics . . . . . . . . . . . . . . 247 Ti-1100Fatiguestrer1gthat10~cycles ...................... 249 Ti- 1100: Fracture toughness of beta forged and

annealedmaterial .................................... 249

Ti-1 100: Ektrical re~iStivity vs tempemhire ................. 247

Ti-11w.Thennalconductivity ........................... 248 Ti-l100:"ypical0.2%~ofbetaforgedmeterial ........... 248

Ti-1100: Room-temperaturefatiguecrackgrowth ............. 249

Ti-1100:Specificheatvstemperature ...................... 247 Ti-1100:ThermalcoefficientofLinearexpansion ............. 248

Ti- 1 100: Yield and tensile strength vs temperature ............. 248 Ti-1 100: Tensile ductility vs temperature .................... 248

IMI 834 Ti-5.8Al-4Sn-3~Zlc0.7Nb-05Md),35Si . 'Igbles IMI 834: Qpical composition range (wt%) and density, ........ 250 MI 834: Summary of typical physical pmpties . . . . . . . . . . . . . . 250 IMI 834: Thermal coefficient of linear expansion . . . . . . . . . . . . . . 250 MI 834: Minimum tensile properties ....................... 25 1

CastIMI834:Fatiguesbrengthatldcycles .................. 252 Cast IMI 834: Fatigue strength at 10' cycles .................. 253 Cast IMI 834: Notched fatigue sangth ..................... 253 Cast IMI 834: Roomtemperature tensile properties ............ 254 Ca~tIMI834:Tensilepropertiesat600~C ................... 254 IMI834:Ropertiesof2mmshect ......................... 255 IMI834:Recommendedheataeatments .................... 255 Ti-l100.Fatigues.gthat1O7cyclcs ...................... 255

IMI 834 Ti-51Al-4Sn-3JZr-0.7Nb-O.SMo-0,35Si . p%Um IMI834:Betaapproachcurve ............................ 250 IMI 834 Young's modulus (dynamic) ...................... 251 Heattreateddiscs ....................................... 251 IMI 834: 0.2% creep strain conditions ...................... 252 IMI834:Stressruptureproperties ......................... 252 IMI 834: Low-cycle fatigue (R = 0) ........................ 252

MI 834: High-cycle fatigue propmies (R = 0) H .............. 253 MI 834: Crack propagation (R = 0) ........................ 253 IMI834:Flowstress .................................... 254

IMI 834: Elevated-temperature low-cycle fatigue . . . . . . . . . . . . . 252

Ti-SAl-2Sn-2ZdMo-4Cr . Tables Ti-5Al-2Sn-2Z~IMo4Cr: Specifications and Compositions .... 256 TI-5AI-2Sn-2ZAMo-4Cr: Commercial Compositions ......... 256 Ti-17: Typical STA high-cyclc fatigue (unnotched) ............ 256 Ti-17: 'Qpical STAlowcyclc fatigue (unnotched) ............. 256 Ti-17: Typical STA lowcycle fatigue (unnotched) ............. 257 TI-17: Effect of reduction ratio on fracture toughness of

diskfmgings ........................................ 258 Ti-17: Plane-strain fracture toughness at mom temperature STA . . 258

Ti-SAl-2Sn-2Zr4M04Cr . Figures

Ti-17: Axial fatigue ofSTAdiskforgings .................... 257 Ti-17: Fatigue crack growth at mom temperature ............. 257 Ti-17: Fracture toughness vs yield strength (aged) ............. 258 TI-17: Effect of solution temperanrre on toughness ............ 259

l'i-6Al-2S4ZF6M0 . 'IgblW

Ti-6A1-2Sn4Zr-6Mo: Commncial compositions . . . . . . . . . . . . . 260 TirbA1-2Sn-4Zr-6Mo: Specifications and compositions ......... 260 TI-6246: Room-temperacun axial fatigue sangth at lo7 cycles . . 261 Ti-6246: Fatigue and tensile data for various

microstructural conditions. ............................ 261 Ti-6246: Fatigue crack growth vs dwell time ................. 262 Ti-6246: Impact toughness ............................... 263 1-6246: Fracture toughness of forgings ..................... 263 Ti-6246: Fracture toughness of forgings of several forging

and hcat treatment conditions and section thicknesses . . . . . . . 263 Ti-6246: Fracture toughness of STA forgings of two forging

conditions and specimen locations ....................... 264

Ti-dAl-2S4ZMiMo . Figures "I-6246: Continuous cooling aansfonnation and aging diagram . . 261 Ti-6246: Continuous cooling transformation diagram .......... 261 Ti-6246: Low-cycle fatigue .............................. 262 Ti-6246:Fracturetoughoessvsyieldstrength ................ 264

Ti4Al4V . Thbh Ti-6Al-4V Wroughtproducts ............................. 265 Ti-6AI-4V and equivalents: specifications and compositions ..... 266 'IF-6A1-4V commercial equivalents: compositions ............. 268 Illushation of quenching rate effect on dmstructurcs of

alloyTi.6A1.4V ..................................... 269

Ti-6AI-4V Lattice parameters after quenching from various temperatures ....................................... 270

Tt-6Al4V Fatigue crack initiation vs heat treatment. .......... 272

TidAl4V extruded rod: LCF from shear strain ............... 273 Ti-6AMV Bartensileptroperties for LCFfigure . . . . . . . . . . . . . . 273 'MA14V: Fatigue and tensile data for various

m i c m s M c o n d i t i o n s ............................. 276 Ti-6Al4V Freaing fatigue in shot-peened and

coatedconditions .................................... 279 TidAl4V Fretting fatigue at room temperature and 350 OC

(660 OF) for alloy in polished and shot-peened conditions . . . . 279 Ti-6Al4V Caption table for bottom fwre on previous page .... 282 Ti-6AI4V: Material condition for HCF seength .............. 283 TidAI4V HCF strength of age-hardened bar . . . . . . . . . . . . . . . . 284 TidAI4V FCP data compared with aluminum and steel . . . . . . . . 307 Ti4Al4V Crack-growth rates for continuously rolled textund

sheetinairandsaltwater .............................. 311 Ti-6Al4V Charpy impact strength and ultimate tensile

strength compared to titanium alloys ..................... 3 14

(51% in.) rounds in various heat treated conditions . . . . . . . . . . . 3 IS Charpy impact strength for castings in s e v d heat

W c o n d i t i o n s .................................... 315 Typical fractute toughness of severa1 alloys . . . . . . . . . . . . . . . . . . 317 Ti-6A1-4V Fracture toughness of powder compacts compared

to companding wrought alloys ........................ 3 19 Ti-6A1-4V (ELI): Fracture toughness of recrystallization

annealedfotgings .................................... 319 Ti-6A14V E f f a of heat tresmrent on h t u r e toughness.

strength, and elongation ............................... 3 19 Ti-6Al4V Effects of overaging on hcture toughness and

tensilestrength ...................................... 319

TidAl4V Effects of specimen type. orientation, and test ttmperature on fracture toughness of electron beam welds . . . . 320

Ti-6A14V Fracture toughness of electron beam welds as a function of processing order and stress-relief temperature . . . . 321

Ti-6A1-4V Variation in crack-growth rate and step width as

LCP and frcrture toughness of TidA14V pancake forgings ..... 272

Ti-6Al4V: Charpy impact strength vs tempereture for 15.9 mm

Ti-6AMV Fracture toughness ............................ 320

a function of hydrogen pressure ......................... 323

Ti-dAMV . Figures TibAl4V Beta transus vs oxygen content . . . . . . . . . . . . . . . . . . 270 TidAl4V: Laaicc parameter of 8 phase .................... 270 TidAl4V Fraction of phase constituents after quenching . . . . . . 270 'K-6A14V Time-temperature-fransformation diagram . . . . . . . . . 270 Aged T i d A 1 4 V HCF slrength in air for s h u c m with a

basaltexture ........................................ 271 Ti-6AI-W Effect of o! grain size on crack-initiation stress ....... 27 1 Ti-6Al4V Low-cycle fatigue of heat-treated bar . . . . . . . . . . . . . . 273 Ti-6Al4V LCF properties of cast and wrought STA alloy . . . . . . . 274 Ti-6A1-4V: LCF of PREP-HIPPIM components . . . . . . . . . . . . . . 274 Ti-6A14V Low-cycle axial fatigue for notched (K, = 3.5)

annealed castings (without HIP) ........................ 274 Ti-6A1-4V Effect of microstructure on fatigue

strength in vacuum ................................... 275 Ti-6Al-4V: Effect of microsmcture on fatigue strength in air ..... 275 Ti-6Al4V ELI: Fatigue strength at cryogenic temperatures ...... 275 Ti-6AI4V Effect of yield strength (YS) on fatigue strength . . . . . 275 Ti-6Al4V S c a m of fatigue strength vs . tensile strength . . . . . . . 276 Ti-6A14V Variation in RT endurance ratio . . . . . . . . . . . . . . . . . . 276 Ti-6Al4V Correlation between endurance limit and peak

residualstress ....................................... 277 X-6A14V Effea of test orientation on fatigue . . . . . . . . . . . . . . . . 277 Ti-6A14V Influence of texture and test direction . . . . . . . . . . . . . 278

Ti-6AI4V Effect of shot peening on fatigue strength . . . . . . . . . . 279 Ti-6Al4V: Effect of shot peening and electrolytic polishing . . . . . 278

Ti-6Al4V Influence of mean stress on HCF

'IT-6A1-4V Fatigue of investment castings aftertmtmcnts . . . . . . 280 TidAl4V Effect of rolling tempaatun on HCF sangth . . . . . . . 280 ndA14V Ef€ect of worlring temperatures on HCF strength ..... 281

HCFstrength ....................................... 281 Ti-6Al4V Effect of annealing h e ........................ 282 TibAl4V: Effect of annealing temperature on fatigue sfren gth. .. 282 Tf-6Al4V Effect of cooling from a-B region on HCF strength . . . 283 'RdAl4V Effect of cooling rates from p region .............. 283 TidAl4V Effect of cooling rate from solution anneal on

agedHCFstrength ................................... 283 'lldAl4V Influence of age hardening on HCF strength . . . . . . . . 284 'K-6A14W HCF strength of age-hardened bar . . . . . . . . . . . . . . . . 284 TidAl-4V Constant-Life diagram for (a + p) annealed bar . . . . . . . 284 'K-6A14V: Constant-Life diagram for STA sbeet ............... 285 'K-6Al4V Constant-life diagram of extrusions at toom

'KdA14V: Constant-life diagram of unnotched duplex-annealed

strength (io'cycles) .................................. 280

Ti-6Al-4V Effect Of f q @ snd heat treatment OD

tempaature(RT). ................................... 285

Etlsheet .......................................... 286

ELIsheet .......................................... 286

&annealedELIplate ................................. 287

ELIplate ........................................... 287 TidAl4V Notched axial fatigue of extrusions at

315"C(4oO0F) ..................................... 288 'R-6Al4V m i d constant-life diagram for unnotclud STA

sheetat315&(600&) .............................. 288 TidAl4V mid constant-life diagram for unnotched STA

sheetat425&(800m .............................. 289 TI-6Al4V Notched vs . unnotched fatigue of STA sheet

at425 "C (800 "F) .................................... 289 Ti-6Al4V Axial fatigue of cast and wrought forms

(R =0.1, uMOtChed) .................................. 290 Ti-6Al-4V Fatigue Life of unnotckd p-annealed plate in aqueous

3.58NaCL ........................................ 290 Ti-6A14V Axial fatigue of unnotched STAplate .............. 291 TibAl4V Axial fatigue of unnotched STA plate . . . . . . . . . . . . . . 291 'IIdA14V Axial fdgue of unnotched STA sheet .............. 292 'KdA14V Fatigue Life of annealed unnotched sheet .......... 2% TilAl4V: Axial fatigue of unnotched STA sheet at 200

and315OC(400and60OoF) ........................... 293 Ti-6A14V Axial fatigue of unnotched s h t at425

and48O0C(800and900OF) ........................... 293 TidAl4V: Wrought and P/M strain life fatigue ............... 294 TidA14V: LCF at mom temperature ....................... 294 'li-6Al-4V Beta annealed strain life fatigue . . . . . . . . . . . . . . . . . . 294 'Ii-6AMV: LCFat 315 "C (600 OF) ......................... 295 TidA1-4V Cyclic softening in beta annealed condition . . . . . . . . . 295 Ti-6A1-4V Notch effects on wrought, cast. and PiM forms . . . . . . 295 AnnealedTi-6Al4V Smooth axial fatigue ................... 2% STA Ti-6Al-4V (a) Notched axial fatigue .................... 2% Annealed TidA14V: Notched axial fatigue .................. 2% STA TtdAl4V Smooth axial fatigue ....................... 297 Ti-6AI-4V Fatigue of notched (K, = 2.53) bannealedplate . . . . . . 297 Ti-6A1-4V Axial fatigue of notched STA plate ................ 298 Ti-6A1-4V Axial notched fatigue in longitudinal direction

ofb ................................................ 298 Ti-6Al4V Axial fatigue of annealed extrusions (YS = 875 m a ) .

smoothandnotched .................................. 299 " i i A l 4 V Axial fatigue of notched (K1 =2.8) STA sheet at 425

and 480 "C (800 and 900 T) ........................... 299 Ti-6A14V Axial fatigue of notched (K, =2.8) STA sheet at 200

and 315 OC (400 and 600 OF) ........................... 300

Ti-6A1-4V Constant-life di- of DA and notched (KT = 2.53)

Ti-6A1-4V Constant-life @am of notched (KT = 2.53)

Ti-6Al4V COWaWlifc for UMOtchd kamreald

List of tam and Flgures / 395

' M A 1 - 4 V Longitudinal axial fatigue of notched (K, = 2.8) S T A s k t .......................................... 300

TidAMV Notched fatigue life of (K, = 2.53) annealed sheet . . . . 301 TidA14V Fatigue of smooth and notched castings compared . . . 301 Ti-6AI-4V Smooth fatigue of castings compared to wrought

IF-6Al4V (a) Smooth and (b) notched axial fatigue at 26o"c(5oooF) ..................................... 302

Realloyed TidAl-4V P M parts: (a) Smooth and (b) notchedfatigue ..................................... 303

Ti-6Al-4V Fatigue bands of I/M and PIM products ............ 303 TidAl-4V Axial fatigue of notched (K, = 2.16) BE

powder specimens ................................... 303 TidA1-4V Axial fatigue of notched (K, = 2.16) BE

powder specimens ................................... 303 TIdA14V Axial fatigue of notched (K, = 2.16) BE

powder specimens with porosity ........................ 303 Ti-6Al4V Fatigue strength in pure water. ................... 304 TidA1-4V Effect of texture and environment on fatigue . . . . . . . . 304 Ti-6A1-4V Fatigue in air and water of castings with varying

oxygencontent ...................................... 305 Ti-6AI-W Fatigue of castings and weldments in water and air . . . 305 TidA1-4V corrosion fatigue: Compared with type 403

stainlesssteel ....................................... 306 TidA14V Weibull plot for 30 specimens in water ............. 306 'KdAI4V Fatigue compared with a stainless steel . . . . . . . . . . . . 306 'KdA14V Fatigue compared with stainless steel . . . . . . . . . . . . . . 307 TIdA14V Betaquenched FCPrates vs. other heat treatments . . . 307 'KdA1-4V Scatterbands for FcPrates of cast and pannealed

TidA1-4V Influence of a morphology on FCPresistance at roomtemperam re.. .................................. 308

Ti-6A14V Wet of recrystallization annealing on FCP in plate. . 309 Beta-annealed Ti-6Al-QV: effect of WidmansWn packet size onFCPrates .......................................... 309 Ti-6A14V forgings: FCPrates for various R ratios . . . . . . . . . . . . 309 Ti-6A14V Effect of microsrmcture and R ratio on FC P. ........ 3 10 Beta-annealed Ti-6A1-4V FCPrates with different

oxygencontents ..................................... 310 1IdA14V Effect of oxygen of steam on near-threshold fatigue

crack growth rates in TidA1-4V ......................... 3 10 'KdAl4V Effect of texture on near-threshold FCP in

NaCl solution ....................................... 310 Ti-6A14V Effect of tea direction and texture on FCP rates . . . . . . 3 11 Ti-6A1-4V: 'Qpicat F C P W in salt water ................... 3 11 TidA14V: FCPbehaviorinsaltwater ...................... 311 Mill-annealed TidAl4V FCPrates in iodide solutions and

distilid water ....................................... 312 Mill-annealed Ti-6Al-4V Effect of testing frequency and AK

on FCPrates in salt water .............................. 312 Beta-annealed 3-6A1-4V Effect of testing frequency and AK

on FCPrates in salt water .............................. 312 Recrystallization-annealed TidA1-4V Effect of dwell loading

and hydrogen on FCP rates ............................ 3 12 Effect of test frequency on AKscc. the transition stress-intensity

factor range for cyclic stress-corrosion cracking . . . . . . . . . . . . 3 13 Ti-6AI-4V: Izd impact strength vs temperature . . . . . . . . . . . . . . . 3 13 Ti-6A14V Charpy impact strength of annealed bar

vstemperature ...................................... 313 3-6A14V: Charpy impact strength of s h e t. ................. 3 14 Ti6A14V: Impact strength of textured plate . . . . . . . . . . . . . . . . . 3 14 T1-6A14V Energy to propagate and Fracture . . . . . . . . . . . . . . . . . 3 14 TidAl-4V Charpyenergyper2.5 mm ...................... 314 3-6A14V Fracture toughness scatter bands . . . . . . . . . . . . . . . . . 3 16 Ti-6Al-W Range of yield strength and fracture toughness . . . . . . 316 TidA1-4V Fracture toughness vs yield strength . . . . . . . . . . . . . . . 3 16

T i d A I 4 V .......................................... 302

wroughtproducts .................................... 308

Ti-6A14V Scatter of FCP data for mill-annealed plate . . . . . . . . . 309

Ti-6A.l-4V Oxygen content/thejmal treatment vs fracture

Ti-6Al4Y (ELI): Annealing tempemhue vs fracture toughness ofplate ............................................ 318

TIdAl4V Fracture toughness vs rolling temperahue tensilestrength ...................................... 318

TI-6A1-4V Fracture toughness vs solution tempemure on tensildMrestrength ............................... 318

Ti-6A1-4V.Frachlremcchanisrnmap ....................... 322

toughness ......................................... 317

Ti-6A14V Fracture toughness of electron beem w a s . . . . . . . . . 321

Ti-6A1-4V Fracture toughness vs oxygen c o v ... 322

fracture toughness ................................... 322

Tl-6A1-4V Fracture toughness of electron beam welds . . . . . . . . . 323 Ti-6Al-4v O ~ S ~ O U S hydrogenembri#lement ................ 324

TIbAI4V Sustained load cracking behavior ................. 324

Ti-6Al-W Crack length as a function of time ................. 326

Tb6A1-4V~TriaAl-4V(I): Low- tempem~

'TT-6Al-4V (ELI): Fracture toughness ....................... 323

'KdA1-4V Step width vs applied stress intensity . . . . . . . . . . . . . . 324

11dA14V Effects of hydrogen content ..................... 325 TI-6A14V Crack length as a function of lime ................. 325

'Ii-6A1-4V Average maximum crack-growth rate vs temperahre . . 326

Ti-6Al-6V-2Sn . 'Igbles

'K-662: Equivalent specifications .......................... 327 'K-662: Commercial compositions ......................... 328 Ti-662 Axial fatigue strength of notched specimens (R = -1) .... 330 75-662 Axial fatigue strength of STA forging (R = 0.1) ......... 330 TI-662: Axial fatigue strength of extrusions (R = 0.1). .......... 330 TI-662: RT axial fatigue strength of annealed plate (R = 0.1) . . . . . 331 Ti.662.AxiaiRTfatiguesaengthofSTAplate ................ 331 Ti-662:Axialfatiguescnngthofsheet ...................... 331

Ti-662: fracture toughness of plate. forging. and billet ....... 337 Ti-662: RTfracture toughness ofplate ...................... 337

Ti-662: RT fracture toughness of plate and fOFgingS ............ 338

Ti-6Al4V-2Sn . Figures

'IT-662: Time-temperatlrte transformations from 850 "C (1560 OF) .................................... 329

Ti-662: Isothermal transformation diagram. .................. 329 Ti-662: Phase transformation diagram ...................... 329 Ti-662: Strain cycling for annded bar ...................... 330 TI-662: Low-cycle axial fatigue ........................... 330 Ti-662.RTaxialfatiguestrengthofforgings .................. 332 li-662: Typical axial fatigue strength ....................... 332

Ti-662: RT smooth axial fatigue of mill annealed plate .......... 332 TIE-662: RT smooth axial fatigue of STA plate ................. 333 Ti-662: RT notched axial fatigue of STA plate ................. 334 'IT-662: Crack growth rates for annealed plate ................. 334 TI-662: Average crack growth rates ......................... 334 li-662: Crack growth of @ annealedplate .................... 335 73662: Crack growth rates at -54 "C for STA specimens ........ 335 Ti-662: Crack growth in simulated body environments . . . . . . . . . 335 Ti-662 Crack growth range at several temperatures . . . . . . . . . . . . 335 Ti-662: Impact toughness of annealed extrusions .............. 336

Ti-662: Fracture toughnesdyield strength .................... 336 3-662: Impact toughness of plate . 25 mm (1 in.) plate

composition: 0.081 02. ............................... 336 Ti-662: Fracture toughness vs temperature ................... 337 Ti-662: Influence of yield strength on fracture toughness ........ 337

Ti-662: RTnotched axial fatigue of mill annealed plate . . . . . . . . . 333

3-662: Impact toughness of STA bar ....................... 336

396 I List of Tables and Figures

Ti-3AI-8V-6Cr-4Mo-42~ (Beta C) . lhbles

Ti-6-22-22s: Summary of typical physical properties . . . . . . . . . . 339 3-6-22-22s: Elastic propaties of forgings . . . . . . . . . . . . . . . . . . . 339 Ti-622-22s: Variation in Young's modulus . . . . . . . . . . . . . . . . . . 339 Ti-6-22-22s: vpical mechanical ptoperties for U-P processed

STAproducts ....................................... 340 TI-6-22-28: Typical mechanical properties for p-processed

STAprcducts ....................................... 340 "3-6-22-22s: ")+pica1 mechanical properties for u-p processed

Ti-6-22-22s: Effect of temperature on tensile. compressive. millannealedproducts ................................ 344

andshearptoperties .................................. 342 Ti-6-22-22s: Stress-rupture and creep properties for STA billet . . . 343 Ti-6-22-22s: Creep propaties of p solution treated and

agedforgings ....................................... 344 Ti-6-22-22s: Transverse axial fatigue of STAplate . . . . . . . . . . . . 345 Ti-6-22-22s: Unnotched axial fatigue of DA f q e d

billet(R=O.l) ...................................... 345 Ti-6-22-22s: Notched axial fatigue of DA forged billet

Ti-6-22-22s: Fracture toughness of sheet .................... 350 Ti-6-22-22s: Fracture toughness and impact toughness. . . . . . . . . 350 Ti-6-22-22s: Typical fiacture toughness of pprocessed

STAprOducts. ...................................... 350 Ti-6-22-22s: Fracture toughness of a + p processed

STAproducts ....................................... 350

(R=O.l,K,=3.0) ................................... 346

Ti-6-222% Ti-6Al-2Sn-2Zr-2Mo-2C1.0.25Si- Figures

T1-6-22-22S: Mill annealed microstructure . . . . . . . . . . . . . . . . . . . 339 'K-6-22-22s: Determination of acceptable processing window . . 341

Ti-6-22-22s: Strength and ductility vs solution beatingtemperature .................................. 341

Ti-6-22-22s: Effect of solution temperature on tensil: properties . 342 Ti-6-22-22s: Yield strength vs aging temperaturn . . . . . . . . . . . . 342 Ti-6-22-22s: High-temperature tensile strength of STA billet . . . . 343 Ti-6-22-22s: High-temperature tensile strength . . . . . . . . . . . . . . . 343 Ti-6-22-22s: Larson-Miller creep curves .................... 344 Ti.6-22.22S.CreepofSTAplate ........................... 344 Ti-6-22-22s: Creep and stress rupture of forged billet . . . . . . . . . . 344 Ti-6-22-22s: Unnotched axial fatigue of DA forged billet . . . . . . . 345 TI-6-22-22s: Notched axial fatigue of DA forged billet . . . . . . . . . 345 Ti-6-22-22s: Fatigue behavior of unnotched STA plate . . . . . . . . . 346 Ti-6-22-22s: Fatigue of notched STA plate . . . . . . . . . . . . . . . . . . . 346 Ti-6-22-22s: Smooth highcycle fatigue ..................... 346 Ti-6-22-22s: Notched highcycle fatigue .................... 346 Ti-6-22-22s: Fatigue crack growth rate in forged . . . . . . . . . . . . . 347 Ti-6-22-22s: Fatigue cracking in 3.5% NaCI of STA plate . . . . . . . 347 Ti-6-22-22s: Fatigue cracking in air of STA plate . . . . . . . . . . . . . . 347

Ti-6-22-22s: Effect of oxygen content on tensile strengths . . . . . . 341

Ti-6-22-22s: Fatigue cracking in 3.5% NaCl of STA plate . . . . . . . 348 Ti-6-22-22s: Fatigue cracking in 3.5% NaCl of STA plate . . . . . . . 348 Ti-6-22-22s: Fatigue crack growth rate of forgings . . . . . . . . . . . . 348 Ti-6-22-22s: Fatigue crack growth rate comparison . . . . . . . . . . . . 348 Ti-6-22-22S: Fatigue crack growth rate vs applied stress

intensity of forgings .................................. 349 Ti-6-22-22s: Fatigue crack growth rate of plate . . . . . . . . . . . . . . . 349 Ti-6-22-28: Fatigue crack growth rate comparison in

3.58NaCl. ........................................ 349

Ti-6-22-22s: 'Qpical m.valws ............................ 35 1 Ti-6-22-22s: Effect of oxygen content on Klc . . . . . . . . . . . . . . . . . 35 1

Ti-3A1-8VdCr-4Mo-4Zr (Beta C): Specificdons ............. 352 T1-3Al-8V-6Cr-4Mo-423 (Beta C): Commercial compositions ... 352 Beta C: Lattice parameters of the oc and p phases in solution heat

treatedandagedplate ................................. 353 Beta C: Fatigue life at high temperatures ..................... 354 Beta C: Material condition in crack growth tests . . . . . . . . . . . . . . . 354 Beta C: Fracture toughness of bar .......................... 355

Beta C: Fracture toughness of billet. forging. and plate .......... 356 Beta C: Fracture toughness of STA billet ..................... 355

Ti-3Al-8VdC14Mo4Zr (Beta C) . Figures BetaC.Effectofagingtemperature ......................... 353

Beta C: Fatigue life of shot peened w k ..................... 353

BetaC: Axial fatigue at high temperature .................... 354

Beta C: Crack growth with high-temperature ST ............... 355

BetaC: Variation of p lattice parameter ...................... 353

Beta C: Fatigue life of recrystallized wire .................... 353

Beta C: Notched fatigue strength at high temperature ........... 354

Beta C: Crack growth with low-temperature ST . . . . . . . . . . . . . . . 355 Beta C: Crack growth in solution treated condition. ............ 355

Ti-lOV-2Fe-3Al- lhblea Ti- IOV-2Fe-3Al: Specifications and compositions . . . . . . . . . . . . . 357 'A-lOV-2Fe-3Al: Commercial compositions .................. 357 Ti-lOV-2Fe-3AI: Fatigue in notched specimens for several

product forms in high-strength and low-strength conditions ... 363 Ti-lOV-2Fe-3AI: Room temperature Charpy impact toughuess

ofSTQAbar ........................................ 366 Ti- 10V-2Fe-3A1: Fracture toughness for several product forms . . . 366 Ti- 1 OV-2Fe-3AI: 'I)pical u I f3 forged room-temperature tensile

Ti-lOV-2Fe-3Al: Fracture toughness of forgings with different aspectratiosofprimarya .............................. 367

Ti-IOV-2Fe-3AI: Fracture toughnessofpowdercompacts . . . . . . . 370 Ti-lOV-2Fe-3AI: Comparison of fracture toughness of powder

compacts vs wrought alloys ............................ 370

properties and fracture toughness of forgings .............. 366

Ti-lOV-2Fe-3AI . Figures Ti-lOV-2Fe-3Al: Effect of temperature on axial fatigue . . . . . . . . . 357 Ti-lOV-2Fe-3AI: Comparison of smooth fatigue strengths ....... 357 Ti-IOV-2Fe3Al: Comparison of smooth fatigue swngths . . . . . . . 358 Ti-lOV-2Fe-3AI: Fatigue endurance and grain size ............. 358 Ti-1 OV-2Fe-3Al: Fatigue of smooth specimens

(1190MPaUTS) .................................... 358 Ti- 10V-2Fe-3AI: Fatigue of smooth specimens

(965 MPa UTS) ..................................... 358 Ti-lOV-2Fe-3Al: Fatigue of smooth specimens

(1 100 M h UTS) .................................... 359 Ti- lOV-2Fe-3A1: S/N data at two mean stress levels . . . . . . . . . . . . 359 Ti-lOV-2Fe-3AI: RTaxial fatigue of STAforgings . . . . . . . . . . . . . 359 Ti-lOV-We-3Al: LCF under strain control ................... 359 Ti- 10V-2Fe-3AI: LCF under load control .................... 360

Ti-lOV-2Fe-3AI: Fatigueof STAnotched(K, =3) specimens . . . . . 360 TI-lOV-2Fe-3AI: Smooth and notched fatigue of STA forgings . . . 360

Ti-lOV-2Fe-3AI: Fatigue with single-hole notch . . . . . . . . . . . . . . . 361 Ti-lOV-2Fe-3AI: Fatigue with doublehole notch .............. 361 Ti-lOV-2Fe-3AI: Notched fatigue performance of forgings . . . . . . 361 Ti-lOV-2Fe-3AI: Fatigue of notched STOA bar. . . . . . . . . . . . . . . 362

Ti-lOV-2Fe-3AI: Notched and smooth fatigue vs Ti-6Al4V . . . . . 360

TI-lOV-2Fe-3AI: Notched fatigue of STAforging .............. 361

TI-lOV-2Fe-3AI: Smoothandnotched fatigue at RT . . . . . . . . . . . . 362 Ti-IOV-2Fe-3Al: Smooth and notched fatigue at 200 'C. ........ 362 Ti-IOV-2Fe3AI: Smoothandnotched fatigue at 425 "C. . . . . . . . . 362

List of T a b k and Figure8 I397

Ti-lOV-2Fe-3AI: Effect of notch geometry on fatigue strength . . . 363 Ti-lOV-2b3AI Fatigue of cast and wrought specimens . . . . . . . . 363 Ti-lOV-2Fe-3AI: Fatigueinpowder compacts . . . . . . . . . . . . . . . . 363 Ti-lOV-2Fe-3AI: Crack growth in two aged conditions. . . . . . . . . 364 Ti-lOV-2Fe-3AI Crack growth in air and 3.5% NaCl ........... 364 '1"1-10V-2I%3Al: FCG with low aspect ratio of primary a . . . . . . . 364 Ti-lOV-2Fe-3AI: FCG with high aspect ratio of primary a . . . . . . 364 TiII-lOV-2Fe-3AI: FCO witb high aspect ratio of primary a ...... 365 Ti-lOV-2Fe-3AI: FCG with low aspect ratio of primary a . . . . . . . 365 Ti-lOV-2Fe-3AI: FCG in STA and direct age conditions . . . . . . . . 365 Ti-lOV-2Fe-3AI: FCG in direct age condition . . . . . . . . . . . . . . . . 365

n-lOV-2Fe-3Al: Fracture toughness vs yield strength .......... 367 Ti-lOV-2Fe-3Al: Plane-strain fracture toughness vs UTS . . . . . . . 367 Ti-lOV-2Fe-3AI: Fracture toughnesshnicrostructurc

forforgings ........................................ 368 ll-lOV-2Fe-3AI: Effect of elongated a on toughness ........... 368 Ti-lOV-2Fe-3AI: Effect of a morphology on toughnesdductility . . 368

TI-lOV-2Fe-3Al: Fracture toughness vs forgingheat treammt . . . 369 Ti-IOV-2Fe-3Al: Toughness vs defect Content . . . . . . . . . . . . . . . . 369 Ti-lOV-2b3Al: Toughness from conventional and hot

dieforging ......................................... 369

Ti-10V-2F~3Al: Fractun toughness vs UTS . . . . . . . . . . . . . . . . . 367

TblOV-2Fe-3AI: F r ~ t ~ e toughness Of forginSS vs finalworking ....................................... 369

Ti-lSV-3Ce3Ab3Sn . 'hbles Ti-lSV-3Cr-3A1-3Sn: Specifications and Compositions . , . , , . , , 371 Ti-15-3: Smooth and notched fatigue ....................... 371 Ti-15-3: Crack growth at AK= 22 MPaG(20 k s i K ) . . . . . . . . 371 Ti-1 5-3: Ftacture toughness of STA plate .................... 372

Beta-21% RT tensile pmperties of sheet vs oxygen content ...... 377 Beta-2 1 S: RT tensile Properties of sheet and bar vs

oxygencontent ..................................... 377 Beta-21 S: Typical room-temperahin aged tensile properties ..... 378 Beta41S: Typical R T b e t a - d e d tensile properties .......... 378 Beta-2 1s: High-temperaturt tensile properties (aged at 540 "c) . . 379 Beta-21s: High-tempereNre tensile p@es (aged at 540 "C) . . 379

Beta-21S:Selectedheattreaemen$ ......................... 381

Ti-15-3:#rfracturetoughnes~of~h~t., ................... 372

Beta-21S.Fra~tureto~ghnes~ ............................. 380

Ti-lSV-3Cr-3AI-3Sn . Figures Ti-15-3: Crack growth in air and salt solution . . . . . . . . . . . . . . . . . 372 Ti.15.3.Craekgro~thdatefotshat ........................ 372 Ti-15-3: Fracture toughness vs Sheet thick;nes~ . . . . . . . . . . . . . . . . 373

TIMETALQP 21s . 'IiablW

Beta-21s: Wical composition range ....................... 374 Beta-21s: Summary of typical physical propedes. . . . . . . . . . . . . 374 Beta31S: Oxidation results from alloy development . . . . . . . . . . . 375 Beta-21% Rcpassivation potential comparison . . . . . . . . . . . . . . . 375 Beta-21s: General corrosion behavior ...................... 375

TIMETAL@ 215 -Figures

Beta-21s: Electrical resistivity vs temperaturr ................ 374 Beta-21s: Corrosion rate 88 a function of HCl concentration . . . . . 375 Beta-21% EfFect of hydrogen on residual ductility ............. 376 Beta.21S.Specificheatvstemperature ...................... 376 Beta-21% Thermal coefficient of linear expansion ............. 376 Beta-21s: Thermal conductivity ........................... 376 Beta-21s: High-temperawetensileproperties ................ 379 Beta-21s: High-temperaturetensileptoperties ................ 380 Beta-21s: Creep results in STAmaterial ..................... 380 Beta-21s: Fatigue crack growth ........................... 380 Beta-21s: Fatigue crack growth ........................... 380 Beta-21s: Tensile yield strength vs agingtime . . . . . . . . . . . . . . . . 381 Beta-21s: Ultimate tensile strengthvs agingtirne .............. 381

Ti-5A1-2Sn4Zrc4McdCr-lFe Beta-CEZ@ -Tables

B&-CEZ@: Chemical composition ........................ 382 Beta-CEZ? Summary of typical physical p-es . . . . . . . . . . . 382 Beta-CEZ?: Young's modulus vs ternpaatun . . . . . . . . . . . . . . . . 383 Be$a-C&': 'Qpical tensile properties ...................... 383 Beta<&: Fatigue crack propagation for lamellar oi

necklaoedmicrostructures ............................. 384 Beta-C&: Hardness kinetics for equiaxed microstructures . . . . . 385

Ti-SA1-2Sn-4Zrc4Mo-2Cr-lFe

Beta-CEZ*: Thermal coefficient of linear expansion vstempemture ...................................... 382

BetaCEZ@: Creep property comparison ..................... 383 Beta-CE??: Low-cycle fatigue for equiaxed microstruclures

BetaCEZ@: Fracture toughness vs yield strength comparison . . . . 384

Beta-CEZ@ - P C ~ U R S

Beta-CEZ@: Yield smngth comparison ..................... 383

aged at 600 "C ...................................... 384

Beta CEZ? Strain-rate sensitivity at 760 & .... . . . . . . . . . . . . . 385

fatigue data book - light structural alloys

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