legg test state overview

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Keith Legg 847-680-9420

Test Status Overview

Dec 13,14, 2000



Keith Legg 847-680-9420

Rationale

A lot of data has been generated in HCAT/CHCAT

program in the past 3 or 4 months

Aim is to show overall status - where we are in testing

and what we have learned overall Put current data in a logical order

Address what we are doing to resolve some testing issues

Suggest some “compartments” for existing and new data



Keith Legg 847-680-9420

Overview

Aircraft use of HVOF coatings

Why are we doing this? -

commercial flight tests

Overall status of JTP tests

JTP - Corrosion, wear,fatigue, embrittlement,

impact

Ancillary - Process specs,

producibility, additional

corrosion, additional fatigue,

failure mechanisms

Conditions seen by real parts

Summary of findings to date

What does all this mean for

actual usage?

Where does it work just fine?

Where do we need to worry?



Keith Legg 847-680-9420

Flight testing -

Why are we doing this?

Flight testing (Boeing, Delta, Lufthansa etc.) shows

acceptable performance with no serious problems

Wear performance much better than chrome

no gouges, striations, flaking, etc. commonly seen in Cr

better seal life if Ra~4” (rapid seal damage if rough)

some FPI crack pattern indications on Lufthansa aft inner

cylinders (Barkhausen showed no crack penetration to

substrate), nothing requiring removal from service

Typical chrome damage - axle



Keith Legg 847-680-9420

Production use of HVOF

WC-Co and WC-CoCr coatings

Component

Coating

Specific-

ation

Notes

Steering collars HVOF, plasma, D-gun

WC-Co

BAC 5851 Boeing OEM coating

Slat tracks

Pan castings

Gimbals

HVOF, plasma, D-gun

WC-18Co


Bolts

Wear rings

D-gun WC-14Co BAC 5851 Boeing OEM coating

Plungers

Fittings

Plasma Cr 2O3 BAC 5851 Boeing OEM coating

Mufflers

Fairings

HVOF, D-gun, plasmaTribaloy 400


Landing gear sleeves, pins D-gun, plasma Cu-

37Ni-5In, WC-18Co


Boeing 747-400 landing gear HVOF WC-CoCr BAC 5851 Boeing OEM coating

Boeing 737 landing gear HVOF WC-CoCr BAC 5851 Overhaul and repair

Airbus 320 landing gear HVOF WC-CoCr Overhaul and repair

F-18 Main landing gear axle HVOF WC-CoCr AMS 2447 Canadian Air Force – flight tested, in

final approval



Keith Legg 847-680-9420


WC-Co and WC-CoCr coatings (cont.)

Sikorsky CH-53 bladedamper

Plasma T400 In final approval for Navy CH-53

fleet

P&W F-119 EngineConvergent Nozzle Actuator

Super D-gun WC-Co

and Plasma T400

HS 4412 Hamilton Sundstrand spec. Engine

likely to be used on JSF

Slat tracks, Boeing Super D-gun WC-18Co BAC 5851 OEM usage

Bombardier Q-400 flaptracks

HVOF WC-Co Bombardier

PPS 24.04

OEM usage

Bombardier Q-400 andGlobal Express door stoppins

HVOF WC-Co Bombardier PPS 24.04 OEM usage

Slat and flap tracks HVOF WC-Co BAC 5851 Overhaul and Repair

Flap track repair – Bombardier Dash 8

HVOF WC-Co RD 8-57-1164

to 1169

Overhaul and Repair

L1011 flap tracks HVOF WC-Co Overhaul and Repair – Titanium

alloy

Boeing 737, 757, 767 landing

gear

HVOF WC-Co BAC 5851 Main and nose landing gear O&R at

Delta Airlines

Parker-Hannifin actuators Various OEM usage – all new-design

hydraulics

Qualified for landing gear repair <0.010”



Keith Legg 847-680-9420


landing gear coatings - Messier-Dowty

Note

production use

on high

performance

aircraft

Program-p/n Part name Type of coating Area Remarks

F/A-18 E/F74A430702

74A430616

Piston head assyRetract Actuator NLG

Cover assyGear/manifold

Diamalloy 1004 (Al bronze) Applied per AMS2447

Tribaloy T400

6.612 OD

8.974 ID

Production part

Production part

F/A-18 C/D74A410603 Head, Piston Shock Absorber

MLGF-18 E/FDiamalloy 1004 (Al bronze)

Applied per AMS2447

OD R&O DRED

Hawker 400034520-1 Lock link outboard forward

door mechanism NLGWC-Co per DCMP 210(AMS2447-7)

Flat stops Production part

REO 450626-01

Tube Restrictor Support AMS 2447-4Ni95-Al5

2.623/2.621 OD R&O

74A410509 Axle of the polygon AMS 2447-9 2.931/3.374polygon

In progress

Cl601R J

17114-1

Shock strut piston MLG WC-Co-Cr per

DCMP 213(AMS 2447-9)

4.614 OD Under evaluation

in service by Air Canada, NIEO

17207-1Shock strut pinMLG

WC-Co-Cr per DCMP 213(AMS 2447-9)

1.498 OD Under evaluationin service by Air Canada, NIEO

A340 CLG37173-10137174-10115173-10115174-101

Sleeve thrust shock strut Tribaloy T400DCMP 203(AMS2447-2)

2.348 ID Production part

BD 100

40672 Pin, Piston Tube

NLG

WC-Co-Cr per

DCMP 213(AMS 2447-9)

0.866 OD Production part



Keith Legg 847-680-9420

Data summary:

Landing Gear JTP - Coupon test data

Data Item Test 25 50 75 100 Pass Fail Notes

Corrosion

C-HCAT salt fog ASTM B-117 x Standard flat

US-HCAT salt fog B117 ??? Modified sample. Retesting

US-HCAT cyclic salt fog GM 9540P/B ??? Modified sample. Retesting

H Embrittlement

US-HCAT Deposition ASTM F-519 x No embrittlement by HVOF

US-HCAT H Evolution ASTM F-519 - - No acceptance criteriaUS-HCAT Environmental Emb. ASTM F-519

Fatigue WC-Co (Hourglass)

US-HCAT in air 0.003" ASTM E-466 x R=-1, 0.1

US-HCAT in air 0.010" ASTM E-466 x R=-1, 0.1

US-HCAT corrosion ASTM E-466 x R=-1, 0.1

Fatigue WC-CoCr (Smooth bar)

C-HCAT air 0.003" thick ASTM E-466 x R=-1. Delamination above 180 ksi load

C-HCAT air 0.010" thick ASTM E-466 ??? R=-1. Delamination above 125 ksi load

C-HCAT corrosion ASTM E-466 ??? R=-1. Rapid corrosion initial tests

C-HCAT low temp. ASTM E-466

Impact

Dropped ball Data being obtained

Gravelometry ASTM D-3170 x Equivalent or better than Cr

Wear

Fretting GEAE Data complete - being analyzed

Osc. piston/bushing Hydraulic simul. Data complete - being analyzed

Completeness



Keith Legg 847-680-9420

Data summary:

Propeller Hub JTP - Coupon test data


Corrosion

WC-Co, WC-CoCr, T800, Ni plate ASTM B-117 Standard 4"x6" flat panel

Fatigue (Hourglass)

WC-Co, T800, Cr ASTM E-466 HSD hourglass, R=0.1

WC-Co, T800 ASTM E-466 HSD notched hourglass, R=0.1Wear

Large stroke and dither HSD HSD wear plates

Toxicity leaching

WC-CoCr, T400, T800 waste EPA 1311 Acetic acid leach

Com leteness



Keith Legg 847-680-9420

Corrosion

C-HCAT B117

JTP work complete

HVOF performed

significantly better than

chrome - Pass

US-HCAT B117

Initial test results reported in

Ottawa, Aug 00

HVOF coatings worse than

Cr - Fail

Appears to be a testing

issue

Outstanding issues - resolution of US-HCAT results Retesting under way

Different sealing - Boeing Cd method

2 different geometries (Flats and cylinders)

2 different deposition conditions (Southwest Aero, Hitemco)

2 different cabinets



Keith Legg 847-680-9420

Embrittlement

Tests partially complete

Sequence 1 - HVOF does not cause embrittlement - Pass

Sequence 2 - Not yet complete

H2 can diffuse through HVOF coating

May need longer bake

Sequence 3 begun - no data yet

Outstanding issues

Environmental embrittlement measurements in process

Coating may lower Kt - calculations and tests under way atHeroux



Keith Legg 847-680-9420

Fatigue - WC-Co

WC-Co

US-HCAT testing complete

All WC-Co air fatigue data

equal to or better than Cr -

Pass

All WC-Co corrosion-fatigue

data equal to or better than

Cr - Pass

Delamination from some

specimens at high cycles

WC-CoCr

WC-CoCr 0.003”

delamination at high load -

Pass below 180 ksi, Fail

above 180 ksi

WC-CoCr 0.010”

delamination at high load -

Pass below 125 ksi, Fail

above 125 ksi

WC-CoCr corrosion-fatigue -

Fail?? Not a structural issue, but a functional issue (Messier-Dowty)

Outstanding issues

Results of WC-CoCr fatigue testing

being addressed under Ancillary Testing



Keith Legg 847-680-9420

Wear

Fretting and sliding (hydraulic)

Data evaluation largely complete

HVOF better than or equal to Cr

Rig and flight tests all show better wear performance Less striation, wear, roughening (Delta, Greene Tweed)

Less wear and leakage of seals (Greene, Tweed)



Keith Legg 847-680-9420

Impact

Drop ball testing

Under way

Gravelometry (Boeing)

Completed - HVOF as good as or better than Cr - Pass



Keith Legg 847-680-9420

Data summary:

Landing Gear JTP - Rig and flight testing


Rig tests

Boeing F-18 LG pins Full scale x HVOF pins included in rig test

Hydraulic testing Hydraulic x Greene, Tweed - long stroke and dithering spectrum

M-D F-18 E/F NLG fat. Fatigue Without catapult loads

M-D F-18 E/F drag brace fat. Endurance

BFG Dash-8/400 MLG Full scale Rig complete, awaiting all test item partsBFG NLG steering act. Full scale

BFG simulated piston fat. Full scale sim Full scale piston fatigue simulation

Boeing C-17 forward MLG Full scale Durability - proposed. Out for coordination

Repair scheme rig (Heroux)

CF-18 A/B NLG shock strut Full scale HVOF restrictor tube - compression, cyclic loading

CF-18 A/B MLG crank assy Full scale Torsion loads equivalent to landing loads

CC-130 steering collar Full scale Endurance life

Flight tests

Delta B737, 757, 767 LG x Internal Delta, not HCAT-sponsored

M-D CF-18 polygon repair x Internal Messier-Dowty, not HCAT-sponsored

NADEP-JAX P-3

C-HCAT DND C-130 C-HCAT testing

KC-135, MLG, NLG piston Air Force - military typical worst case

F-16 NLG Air Force - high performance worst case

Completeness



Keith Legg 847-680-9420

Data summary:

Propeller Hub JTP Rig and flight testing


Rig tests

54H60 low pitch stop lever sleeve Piston stroke WC-Co and T800

Flight tests

P-3 propeller 275 flight hrs Tail shaft hub and sleeve lever

Completeness



Keith Legg 847-680-9420

Hydraulic testing - Greene, Tweed

PTFE (Enercap) much

better performance with

WC

low leakage

low rod wear Elastomer rapidly

damaged

not a problem with long

stroke utility actuators and

landing gear at 4 Ra

5

1 5

2 5

3 5

4 5

WC-Co, ACT

Tribaloy, ACT

Chrome, ACT

WC-Co-Cr, Enercap

WC-Co, Enercap

Tribaloy, Enercap

Chrome, Enercap

0

500

1000

1500

2000

2500

L e a k a g e

( g r a m s )

Cycles (mil li ons) 4-9 ” Ra



Keith Legg 847-680-9420

Landing gear rig tests

Boeing F/A-18 E/F landing gear pins

HVOF coatings “passed” full scale rig fatigue test

darkened, but no wear damage, passed MPI

Outstanding - Additional full scale tests to be done by

C-HCAT

Messier-Dowty F-18 E/F NLG fatigue

Messier-Dowty F-18 E/F drag brace fatigue

including catapult loads

BFG Dash-8/400 MLG BFG NLG steering actuator

BFG simulated piston fatigue



Keith Legg 847-680-9420

Flight tests

Delta B737, 757, 767 nose and main landing gear

Inner cylinders, axles, axle sleeves

Passed - WC-CoCr qualified for O&R

Boeing 767-400

HVOF WC-CoCr flight qualified and used in production

Canadian F-18 MLG

Messier-Dowty polygon repair

WC-CoCr

Repair scheme approved

Outstanding - NADEP-JAX P3, DND C-130 testing



Keith Legg 847-680-9420

Data summary -

Ancillary tests


Process parameters

US-HCAT WC-Co DOE - -

C-HCAT NRC WC-CoCr DOE - -

Commercial - SWA, Hitemco - - Boeing QPL processes

Grinding/finishing

NADEP-JAX - - Low stress grind used on samples

Delta Airlines - - Used on flight test landing gear

HerouxStripping

NADEP-CP, S'west Aero x WC-Co and WC-CoCr strip w/Rochelle

CTC water jet x Incomplete stripping

Heroux

R&O Fluid compatibility

Heroux

NDI

Heroux

Delta, Boeing flight tests - - FPI, Barkhausen good; MPI poor

Corrosion

Beach exposure x Flat samples - generic tests

Salt fog B117 x Flat samples - generic tests

Cyclic salt fog GM 9540P/B x Flat samples - generic tests

US-HCAT comparison tests B117 New seal; flat, round, var. vendors, var. cabinets

Fatigue (Smooth bar)

US/C-HCAT WC-CoCr air ASTM E-466

Fracture mechanisms

C-HCAT NRC/Orenda - -

Specifications AMS specs - - Powder, grinding, coating

Completeness



Keith Legg 847-680-9420

Process parameters

WC-Co optimized by Jerry Schell by DOE methods

OO-ALC, Hitemco - JP 5000, DJ

Process designed for 8-12 Almen compressive stress

WC-CoCr optimized by Jean-Gabriel Legoux, NRC byDOE methods

DJ-gun at NRC and VacAero

Process designed for 8-12 Almen compressive stress

Coating parameters different from QPL conditions used by

Southwest Aero



Keith Legg 847-680-9420

Grinding and finishing

Overall finding - for seals need 4” or less Ra

Use fine grind or superfinish (specify other parameters?)

Low stress grinding developed by Jon Devereaux at

NADEP-JAX used on all US-HCAT samples

Surface measurement and superfinishing developed

for landing gear by Jay Randolph at Delta

Testing carried out by John Falkowski (Boeing) andJim Nuse (Southwest Aeroservice) - AESF paper

Additional testing under way

Boeing, SW Aero, Sulzer Metco, Engelhard, Praxair, Green

Tweed, Supfina, Delta



Keith Legg 847-680-9420

Stripping

Water jet does not work very well

Rochelle salt works well for WC-Co and WC-CoCr

SW Aero, Sulzer Metco

NADEP-Cherry Point, NTS Testing at Praxair and others shows no embrittlement

with strippers

No good method for T400 yet

Outstanding - need good chemical strip for Tribaloy



Keith Legg 847-680-9420

Fluid compatibility

Under way shortly at Heroux

Will include evaluations of hydrogen embrittlement due

to fluids



Keith Legg 847-680-9420

NDI

FPI best method so far

Delta, Boeing

MPI not effective

Boeing has used Barkhausen with some success Heroux testing begun

Outstanding - how detect cracks in substrate without

removing coating?



Keith Legg 847-680-9420

Corrosion

All HCAT generic, C-HCAT, Lufthansa data on flats

shows HVOF having better performance than Cr

US-HCAT Landing gear JTP data on rods showed worse than

Cr - Fail

Repeating with better edge seal - comparing sample shapes,deposition conditions, test locations

Outstanding - Resolution of poor US-HCAT test

performance (under way)



Keith Legg 847-680-9420

Fatigue and fracture

Fatigue of WC-CoCr - the picture folks took back from

Ottawa meeting



Keith Legg 847-680-9420

Fatigue and fracture

Findings of cracking by AFRL (Bob Ware)

Careful analysis done at NRC (Jason Dyer, Peter Au)

WC-CoCr fails, cracks and delaminates under high compressive load

(R=-1)

0.003” coating, failure at 180 ksi and above

0.010” coating, failure at 125 ksi and above (note that thicker coating

carries more load)

cracks grow down from coating surface and often run parallel to

interface (similar mechanism to that designed into composites)

cracks do not appear to propagate from coating into substrate

Surfaces of WC-CoCr fatigue specimens from Southwest Aeroservice

also show crack pattern and some spalling at failure and runout

This shows there may be operational limits of WC-CoCr



Keith Legg 847-680-9420

Where should we be testing?

What are the real-world requirements?

What are the functional limits of WC-CoCr and WC-Co?

Questions:



Keith Legg 847-680-9420

Bend test of Praxair WC-CoCr.

Reported by Jay Randolph, Delta

Airlines, July 1998

Fatigue and cracking - historical

Fracture data - John Quets, Shane Arthur

WC-Co initially designed using bend test cracking data

WC-CoCr designed to have better corrosion performance, but

lower fracture strength

So, WC composite coatings balance hardness and wear resistance against brittleness (fracture strength)

1998 - Crack-like indications found

by FPI on aft side of WC-CoCr-

coated Lufthansa landing gear.

Barkhausen analysis by Boeingshowed no crack propagation into

steel. Returned to service - no

reported problems.



Keith Legg 847-680-9420

Landing gear design and fatigue testing

Designers do not design to specimen test data

Coupons provide stress engineers the data to start analyzing

for customer and air-worthiness justification

Difficult to translate from load on full scale item to stress on

test coupon

Qualification always depends on full-scale item fatigue testing

under spectrum loading to 2 or 4 lifetimes

Bulk of public domain data for AerMet 100 was run at

150 ksi or less (Roger Eybel) a few points were run higher for interest sake



Keith Legg 847-680-9420

Fatigue - Loads on Landing Gear

Name Company Maximum

stress

(kpsi)

R ratio Sample type Notes

Gary Erickson Boeing Commercial 170 0.1 Large hourglass Vendor qual test

Roque Panza-Giosa BFG 180 -1 Al alloys 20ksi

Craig Edwards GA/Air Force 180 -1 Actual LG 180kpsi is once-in-a-lifetime

event. 135 normal use

Roger Eybel Messier Dowty 150 A100 test

specimens

Bulk of public domain data -

some at higher load for

interest only

Dave Weldon Messier Dowty 211 Full scale gear Drag Brace Trunnion Pin

Test - max bending stress

Michael Kane NAVAIR 180 Test specimens Limit Ultimate (P3, E6, V22)

Michael Kane NAVAIR 240 Test specimens Design Ultimate (high

performance)Nihad Ben-Salah Heroux 195 0.1, -1 Test specimens 4340 (90% of yield)

207 0.1, -1 Test specimens 300M (90% yield)

225 0.1, -1 Test specimens A100 (90% of y ield)



Keith Legg 847-680-9420

Fatigue - Loads on Landing Gear

Makes no sense to test coatings above levels used in

full rig tests

Looks as though we have the following maximum

needs:

Commercial 170 ksi, R=0.1

Military, typical 180 ksi, R=-1

Military, high performance 240 ksi, R=-1

Questions:

At what loads/cycles were F-18 landing gear qualified?

Do you really go to yield thousands of times?



Keith Legg 847-680-9420

Summary of major ongoing work

Corrosion

Additional tests planned

samples made

Fatigue

C-HCAT testing 0.003” WC-CoCr below 180 ksi

Rethinking tests for 0.010”

WC-CoCr

Comparative testing with SW

Aero WC-CoCr and WC-Co

Embrittlement

Environmental embritt.

Ball impact - in progress

Producibility testing

Heroux - grinding, stripping,

NDI, fluids, etc.

Rig testing

BFG, Messier-Dowty

Flight testing

NADEP-JAX P3

DND CC-130



Keith Legg 847-680-9420

Remaining issues being resolved

US-HCAT corrosion testing to be redone

obviously testing problem

Fatigue testing

Not a structural issue that will cause failure, but a functional

issue that will impose limits

Clearly define fatigue limits and requirements

Understand strain-to-failure, fatigue, residual stress relationships

Definition of load/thickness limits for WC-Co as done for WC-

CoCr WC-CoCr with hourglass specimens to define S/N curve

comparable with WC-Co per JTP?



Keith Legg 847-680-9420

Where does qualification look good?

Commercial

no brainer - in production

Military - general

likely to work with WC-Co

may be near edge of envelope for WC-CoCr

High performance military

(primarily fighters)

need to define operational

loads carefully to match qualof existing gear

may need lower hardness,

higher toughness material

Full article tests - rig, flight



K ith L 847 680 9420

Remaining issues

US-HCAT corrosion testing to be redone

obviously testing problem

Fatigue testing of WC-CoCr with hourglass specimens

define S/N curve comparable with WC-Co per JTP

Definition of load/thickness limits for WC-Co

as done for WC-CoCr

legg test state overview

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