MATERIALS FOR ENGINEERS - Cambridge University …assets.cambridge.org/97805218/99970/frontmatter/9780521899970... · MATERIALS FOR ENGINEERS This text is intended for a ﬁrst undergraduate

MATERIALS FOR ENGINEERS

This text is intended for a first undergraduate course in materials sci-ence and engineering with an emphasis on mechanical and electricalproperties. The text features numerous useful examples and exercises.It differs from other available texts in that it covers topics of greatestinterest in most undergraduate programs, leaving more specialized andadvanced coverage for later course books. The text begins with phasesand phase diagrams. This is followed by a chapter on diffusion, whichtreats diffusion in multiphase as well as single-phase systems. The nextseveral chapters on mechanical behavior and failure should be of par-ticular interest to mechanical engineers. There are chapters on iron andsteel and on nonferrous alloys, followed by chapters on specific types ofmaterials. There is an emphasis on manufacturing, including recycling,casting and welding, powder processing, solid forming, and more mod-ern techniques, including photolithography, vapor deposition, and theuse of lasers.

William F. Hosford is a professor emeritus of materials science and engi-neering at the University of Michigan. Professor Hosford is the authorof a number of books, including the leading selling Metal Forming:Mechanics and Metallurgy, Third edition (with R. M. Caddell); Mechan-ical Behavior of Materials (Cambridge); Intermediate Materials Science(Cambridge); The Mechanics of Crystals and Textured Polycrystals;Physical Metallurgy; and Reporting Results (with D. Van Aken; Cam-bridge).

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Cambridge University Press978-0-521-89997-0 - Materials for EngineersWilliam F. HosfordFrontmatterMore information

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Materials for Engineers

William F. HosfordUniversity of Michigan






cambridge university pressCambridge, New York, Melbourne, Madrid, Cape Town, Singapore, Sao Paulo, Delhi

Cambridge University Press32 Avenue of the Americas, New York, NY 10013-2473, USA

www.cambridge.orgInformation on this title: www.cambridge.org/9780521899970

c© William F. Hosford 2008

This publication is in copyright. Subject to statutory exceptionand to the provisions of relevant collective licensing agreements,no reproduction of any part may take place withoutthe written permission of Cambridge University Press.

First published 2008

Printed in the United States of America

A catalog record for this publication is available from the British Library.

Library of Congress Cataloging in Publication Data

Hosford, William F.Materials for engineers / William F. Hosford.

p. cm.Includes bibliographical references and index.ISBN: 978-0-521-89997-0 (hardback)1. Materials – Textbooks. I. Title.TA403.H627 2008620.1′1 – dc22 2008007734

ISBN 978-0-521-89997-0 hardback

Cambridge University Press has no responsibility forthe persistence or accuracy of URLs for external orthird-party Internet Web sites referred to in this publicationand does not guarantee that any content on suchWeb sites is, or will remain, accurate or appropriate.






Contents

Preface page xv

1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Properties 1Bonding 2Types of Materials 3Crystalline Materials 4Amorphous Materials 6Note of Interest 7Problems 7

2 Phases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

What Is a Phase? 8Phase Diagrams 8Lever Law 9Intermediate Phases 11Invariant Reactions 12Effects of Pressure 12Solid Solutions 13Grain Structure 14Grain Size 14Notes of Interest 15Problems 16

3 Diffusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Fick’s First Law 18Fick’s Second Law 18Solutions of Fick’s Second Law 19Junction of Two Solid Solutions 20Temperature Dependence of Diffusivity 21

v






vi Contents

Diffusion in Systems with More than One Phase 22Notes of Interest 26Problems 26

4 Mechanical Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Stress and Strain 28Elasticity 28Variation of Young’s Modulus 30Plastic Deformation 31Strength Dependence on Grain Size 35Solid Solution Strengthening 36Cold Work 36Hardness 38Slip 38Notes of Interest 39Problems 40

5 Mechanical Failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Fracture 42Creep 46Fatigue 47Toughness 53Fracture Mechanics 54Thermal Shock 55Delayed Fracture 56Notes of Interest 57Problems 58

6 Annealing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Stages of Annealing 60Recovery 60Recrystallization 60Grain Growth 64Note of Interest 66Problems 66

7 Iron and Steel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

Steels 68Pearlite Formation 69Alloying Elements in Steel 70Martensite Formation 71Nature of Martensite 72Hardenability 73Quenching 76






Contents vii

Tempering 77Special Heat Treatments 78Steel Classification System 79Low-carbon Steels 80Stainless Steels 81Cast Iron 81Notes of Interest 82Problems 83

8 Nonferrous Metals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

Aluminum 85Copper and Copper Alloys 89Magnesium 91Titanium 91Nickel-base Alloys 92Zinc 93Notes of Interest 93Problems 94

9 Casting and Welding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

Casting 95Macrostructure of Castings 95Dendrite Formation 96Liquid-to-solid Shrinkage 96Solid-state Shrinkage 98Segregation 98Gas Evolution 100Casting Processes 100Fusion Welding 101Solid-state Welding 102Notes of Interest 102Problems 104

10 Solid Shaping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

Bulk Forming 105Hot Working vs. Cold Working 106Sheet Forming 107Note of Interest 109Problems 109

11 Polymers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

Thermoplastics 110Degree of Polymerization 110Molecular Weight 111






viii Contents

Branching 113Cross-linking 113Stereoisomerism 113Copolymers 114Molecular Configuration 115Thermosetting Polymers 115Addition Polymerization 116Condensation Polymerization 117Common Polymers 118Glass Transition 118Additives 120Degradation 121Properties and Uses of Polymers 121Epoxies 124Silicones 124Notes of Interest 124Problems 124

12 Polymer Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125

Cooling 125Injection Molding 125Compression Molding 126Transfer Molding 126Bulk Extrusion 127Blown Films and Blow Molding 128Fiber Drawing and Rolling 128Thermoforming 128Foaming 129Notes of Interest 129Problems 129

13 Glasses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

Structure of Silicate Glasses 130Chemical Compositions 131Bridging and Non-bridging Oxygen Ions 131Glass Viscosity 132Thermally Induced Stresses 133Vycor® 135Devitrificaton 136Photosensitive Glass 136Other Inorganic Glasses 136Residual Stresses 137






Contents ix

Strength of Glasses 138Shaping Glass 138Metallic Glasses 139Notes of Interest 141Problems 141

14 Crystalline Ceramics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142

Ceramics 142Slip Systems 142Ionic Bonding 143Hardness 143Porosity 145Variability of Strength 146Toughening of Ceramics 147Growth of Single Crystals 149Notes of Interest 150Problems 150

15 Powder Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151

Powder Compaction 151Sintering 151Intermediate and Final Stages of Sintering 153Loss of Surface Area 154Particle Size Effect 154Grain Growth 155Activated Sintering 156Liquid Phase Sintering 157Hot Isostatic Pressing 158Note of Interest 158Problems 158

16 Pottery and Concrete . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160

Clay 160Processing of Clay Products 160Forms of Pottery 162Hydration Reactions 162Portland Cement 163Concrete Mixes 164Asphalt Concrete 165Notes of Interest 165Problems 165






x Contents

17 Composites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166

Fiber-reinforced Composites 166Elastic Behavior of Fiber-reinforced Composites 166Strength of Fiber-reinforced Composites 170Volume Fraction Fibers 171Fiber Length 172Failures with Discontinuous Fibers 172Typical Properties 173Particulate Composites 173Lamellar Composites 175Notes of Interest 176Problems 176

18 Carbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178

Diamond 178Graphite 179Carbon Fibers 180Amorphous Carbon 180Fullerenes 181Nanotubes 181Notes of Interest 182Problems 183

19 Fibers, Foams, and Porous Materials . . . . . . . . . . . . . . . . . . . . . . 184

Fibers 184Fabrication of Porous Foams 185Morphology of Foams 185Mechanical Properties of Foams 186Honeycombs 187Application of Porous Materials 187Notes of Interest 187Problems 188

20 Electrical Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189

Conductivity 189Metallic Conduction 190Ionic Conduction 192Energy Bands 193Intrinsic Semiconduction 194Extrinsic Semiconduction 196III-V Semiconductors 198n-p Rectifiers 199Transistors 200Dielectric Properties 200






Contents xi

Piezoelectric Behavior 203Notes of Interest 204Problems 205

21 Optical and Thermal Properties . . . . . . . . . . . . . . . . . . . . . . . . . 206

Spectrum of Electomagnetic Radiation 206Index of Refraction 207Reflectivity 209Absorption 209Opacity 210Luminescence 210Light-emitting Diodes (LEDs) 211Photovoltaic Cells 211Lasers 211Fiber Optics 211Thermal Expansion 212Thermal Conductivity 212Specific Heats 214Latent Heats of Transformation 214Thermocouples 214Notes of Interest 215Problems 215

22 Magnetic Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216

Ferromagnetism 216Domains 216Saturation Magnetization 217Ceramic Magnets 218The B-H Curve 219Soft Magnetic Materials 220Hard Magnetic Materials 220Curie Temperature 221Magnetic Memory Storage 221Notes of Interest 222Problems 222

23 Corrosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224

Aqueous Corrosion 224Passivity 227Corrosion Protection 227Rust 228Direct Oxidation 228Notes of Interest 229Problems 230






xii Contents

24 Modern Manufacturing Techniques, Surface Treatments,and Recycling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231

Two-dimensional Photolithography 231Photo-stereolithography 232Laser Beams 232Electron Beams 233Electrical Discharge Machining 233Plasma Coating 233Ion Implantation 234Recycling of Metals 234Recycling Plastics 235Recycling Glass and Paper 236Notes of Interest 237Problems 237

APPENDIX 1: Wood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239Structure 239Dimensional Changes with Moisture 240Anisotropy of Properties 242Plywood 242Notes of Interest 242Problems 243

APPENDIX 2: Miller Indices for Planes and Directions . . . . . . . . . . . . . . . . . . . 244Planar Indices 244Direction Indices 244Families of Planes and Directions 245Notes of Interest 245Problem 246

APPENDIX 3: X-ray Diffraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247Note of Interest 247Problem 248

APPENDIX 4: Surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249Relation of Surface Energy to Bonding 249Grain Boundaries 250Segregation to Surfaces 250Measurements of Relative Surface Energies 251Surfaces of Amorphous Materials 252Note of Interest 252Problems 253

APPENDIX 5: Dislocations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254Edge and Screw Dislocations 254Stress Fields 256






Contents xiii

Note of Interest 257Problems 257

APPENDIX 6: Avrami Kinetics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258Avrami Kinetics 258Note of Interest 260Problems 260

APPENDIX 7: Organic Chemistry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261Bonds 261Bond Energies 261Bond Angles 262Note of Interest 263Problems 264

APPENDIX 8: Average Molecular Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . 265Molecular Weights 265Note of Interest 266Problems 266

APPENDIX 9: Bond Geometry in Compounds . . . . . . . . . . . . . . . . . . . . . . . . 267Coordination 267Ionic Radii 269Note of Interest 270Problems 270

APPENDIX 10: Weibull Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271Weibull Analysis 271Note of Interest 273Problem 273

Index 275






Preface

The importance of materials to civilization is attested to by the names we give tovarious eras (Stone Age, Bronze Age, and Iron Age). We do not consider presenttimes in terms of one specific material because so many are vital, including steel. Thecomputer age would not be possible without silicon in computer chips.

Most introductory texts on materials science and engineering start with topicsthat are not of great interest to most engineers: atomic bonding, crystal structures,Miller indices. This introductory materials text differs from others because it is writtenprimarily for engineers. It is shorter than most other materials texts so that it caneasily be covered in one term. Emphasis is on mechanical and electrical properties ofinterest to most engineers. Thermal, optical, and magnetic behaviors are also covered.In addition, processing is treated in some detail.

Topics like X-ray diffraction, Miller indices, dislocations and coordination incompounds, surfaces, average molecular weights, Avrami kinetics, and Weibull anal-ysis, which are of great interest to materials scientists but of little interest to mostengineers, are covered only in the appendices. There is also an appendix on wood.There is no treatment of crystal systems, the Hall effect, or ferroelectricity.

After an introductory chapter, the text starts with phases and phase diagrams.This is followed by a chapter on diffusion, which treats diffusion in multiphase aswell as single-phase systems. The next several chapters on mechanical behavior andfailure should be of particular interest to mechanical engineers. There are chapterson iron and steel as well as nonferrous alloys. The chapters on electrical and opticalproperties should be of particular interest to electrical engineers. These are followedby chapters on specific types of materials: polymers, glasses, crystalline ceramics, clayproducts, forms of carbon, composite materials, concrete, and foams.

There is an emphasis on manufacturing, including recycling, casting and weld-ing, powder processing, solid forming, and more modern techniques, including pho-tolithography, vapor deposition, and the use of lasers. The text has been influencedby Elements of Material Science by L. H. Van Vlack and Engineering Materials andTheir Applications by R. A. Flinn and P. J. Trojan. I want to thank David Martin forhis help with polymers.

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MATERIALS FOR ENGINEERS - Cambridge University …assets.cambridge.org/97805218/99970/frontmatter/9780521899970... · MATERIALS FOR ENGINEERS This text is intended for a ﬁrst undergraduate