ULTRASONICS Fundamentals • Technology • Applications

Second Edition, Revised and Expanded

DALE ENSMINGER Battelle Columbus Laboratories Columbus, Ohio

MARCEL DEKKER, INC. New York and Basel

Contents

Preface to the Second Edition Ш Preface to the First Edition v

1 Ultrasonics—A Broad Field 1

I . In t roduct ion 1 I I . History 2

III . Ultrasonics in Nature 4 IV. Ultrasonic Transmi t t e r s 8 V. Ultrasonic Receivers 8

VI. Low-Intens i ty Applications 9 VII. High- In tens i ty Applications 10

VIII. Medical Appl icat ions-Low- and High- In tens i ty 11 References 12

2 Elastic Wave Propagation and Associated Phenomena 13

I . In t roduct ion 13 II . Power Delivered to an Oscillating System 15

HI . The Velocity of Sound 16 IV. Impingement of an Ultrasonic Wave on a

Boundary Between Two Media 21 V. Transmission T h r o u g h Thin Plates 40

VI. Diffraction 42 VII. S tanding Waves 47

VIII. Doppler Effect 50 IX. Beats 54 X. Attenuat ion of an Ultrasonic Wave 55

XI. Relaxation 64 XII. Cavitation 66

References 68

X Contents

3 Fundamental Equations Employed in Ultrasonic Design and Applications 71

I. Introduction 71 II. Simple Spring-Mass Oscillator 73

III. Wave Equations 78 IV. Solution of the Plane-Wave Equation, Linear

System 80 V. The Transverse-Wave Equation 88

VI. Solution of the Transverse-Wave Equation 90 VII. Plate Waves 101

References 109

4 Design of Ultrasonic Horns for Processing Applications 111

I. Introduction 111 II. The Horn Equation 112

III. Types of Horns 112 IV. Combining Sections of Different Configurations

for Practical Applications 130 V. Effect of Damping on the Operation of Horns 132

VI. Wide Horns and Horns of Large Cross Section 134 References 138

5 Basic Design of Ultrasonic Transducers 139

I. Introduction 139 II. Equivalent Circuits 142

HI. Piezoelectric Transducers 142 IV. Magnetostrictive Transducers 160 V. Electromagnetic Devices 165

VI. Pneumatic Devices (Whistles) 166 VII. Mechanical Devices 170

VIII. Some Special High-Frequency Transducers 171 IX. General Remarks 174

References 175

6 Determining Properties of Materials 179

I. Introduction 179 II. Methods of Measuring Velocity of Sound 180

HI. Low-Frequency Measurements of Elastic Moduli and Poisson's Ratio 192

IV. Viscosity Measurements by Ultrasonics 197 V. Determining Properties of Plastics and High

Polymers 199 VI. General Comments on Measuring Acoustical

Properties of Materials 200 VII. Acoustical Properties of Materials 205

References 230

x i

7 Nondes t ruc t i ve T e s t i n g - B a s i c Methods and General Cons idera t ions 233

I . In t roduct ion 233 I I . Basic Methods 233

H I . Factors Affecting Resolution and Sensi t ivi ty 237 IV. Unconventional Techniques Used for Nondest ruct ive

Tes t ing 240 V. Ins t rumenta t ion 250

References 269

8 Use of U l t rason ics in the Nondes t ruc t i ve T e s t i n g of Metals 273

I . In t roduct ion 273 I I . In te rna l S t r u c t u r e of Metals 274

II I . Inspect ion of Basic S t r u c t u r e s and Produc t s 288 IV. Inspect ion of Hot Metals 322 V. Determination of Bond In t eg r i t y 324

VI. Th ickness Measurements 326 VII . Inspect ion of Solder Joints 330

VIII . In-Serv ice Inspection of Nuclear Reactors 333 References 337

9 Use of U l t rason ics in the Inspect ion of Nonmetals 343

343 343 345 345 345 348 349 349 350 352 354 356 356

10 Imag ing , Process C o n t r o l , and Miscel laneous Low-In tens i t y App l i ca t ions 359

I . In t roduct ion 359 II . Ultrasonic Imaging 359

I I I . Process Control 377 IV. Underwater Applications 378 V. Delay Lines 379

VI. Applications in Air 380

I. I I .

I II . IV. V.

VI. VII. / H I .

IX. X.

XI. XII.

In t roduct ion Concrete Timber Plywood Ceramics and Ceramic Coatings Ti res Leather Paper F ibrous-Bonded Composites Plast ics Adhesive Bond In t eg r i t y Animal Tes t ing References

xii Contents

VII. Measuring Fluid Flow, P r e s s u r e , and Tempera ture 383 VIII . Indica t ing the Net Load of a Vehicle 387

References 388

11 Applications of High-Intensity Ultrasonics—Basic Mechanisms and Effects 391

I . In t roduct ion 391 I I . General Discussion 392

H I . Mechanical Effects 394 IV. Chemical Effects 402 V. Metallurgical Effects 413

References 415

12 Applications of High-Intensity Ultrasonics Based on Mechanical Effects 419

I . In t roduct ion 419 I I . Cleaning 420

I I I . Machining, Forming, and Joining 438 IV. Liquid Atomization and Droplet Formation 467 V. Agglomeration and Flocculation 474

VI. Dry ing and Dewatering 474 VII. Agr icu l tura l Applications 479

VIII. Pest Control 480 IX. Control of Foams 481 X. Coating Materials and Part ic les 481

XI. Prepara t ion of Carbon Spheres 482 XII . Glassware Tes t ing 482

XIII . Dispersions 482 References 487

13 Applications of Ultrasonics Based on Chemical Effects 493

I . In t roduct ion 493 I I . Accelerated Etching 493

HI . T r e a t i n g Beve rages , Ju i ce s , and Essential Oils 495 IV. Treatment of Sewage 496 V. Extract ion Processes 497

VI. Demulsification of Crude Petroleum 499 VII. Miscellaneous Chemical Effects and Applications 499

VIII . Ultrasonic Catalysis and Chemical S y n t h e s i s -General Comments 501

IX. Electrolysis and Electroplat ing 505 References 506

Contents x i i i

14 Medical Applications of Ultrasonic Energy 511

I . In t roduct ion 511 I I . Power Measurements and Dosages 512

II I . Basic Mechanisms and Principles 513 IV. Diagnosis 516 V. T h e r a p y 530

VI. S u r g e r y 544 VII. Tissue Character izat ion 549

VIII. Ancillary Applications of Ultrasonics in Medical Pract ice 551 References 552

Glossary 559 Author Index 563 Subject Index 569