Engineering Materials 1 (eBook)

Engineering Materials 1 2
Contents 6
General introduction 12
Chapter 1 Engineering materials and their properties 16
1.1 Introduction 17
1.2 Examples of materials selection 19
Part A Price and availability 30
Chapter 2 The price and availability of materials 32
2.1 Introduction 33
2.2 Data for material prices 33
2.3 The use-pattern of materials 35
2.4 Ubiquitous materials 36
2.5 Exponential growth and consumption doubling-time 38
2.6 Resource availability 39
2.7 The future 41
2.8 Conclusion 42
Part B The elastic moduli 44
Chapter 3 The elastic moduli 46
3.1 Introduction 47
3.2 Definition of stress 47
3.3 Definition of strain 50
3.4 Hooke’s law 51
3.5 Measurement of Young’s modulus 52
3.6 Data for Young’s modulus 53
Chapter 4 Bonding between atoms 58
4.1 Introduction 59
4.2 Primary bonds 60
4.3 Secondary bonds 63
4.4 The condensed states of matter 66
4.5 Interatomic forces 66
Chapter 5 Packing of atoms in solids 70
5.1 Introduction 71
5.2 Atom packing in crystals 71
5.3 Close-packed structures and crystal energies 71
5.4 Crystallography 73
5.5 Plane indices 75
5.6 Direction indices 76
5.7 Other simple important crystal structures 77
5.8 Atom packing in polymers 79
5.9 Atom packing in inorganic glasses 80
5.10 The density of solids 81
Chapter 6 The physical basis of Young’s modulus 88
6.1 Introduction 89
6.2 Moduli of crystals 89
6.3 Rubbers and the glass transition temperature 91
6.4 Composites 93
6.5 Summary 96
Chapter 7 Case studies in modulus-limited design 100
7.1 Case study 1: a telescope mirror—involving the selection of a material to minimize the deflection of a disc under its 101
7.2 Case study 2: materials selection to give a beam of a given stiffness with minimum weight 106
7.3 Case study 3: materials selection to minimize the cost of a beam of given stiffness 108
Part C Yield strength, tensile strength and ductility 112
Chapter 8 The yield strength, tensile strength and ductility 114
8.1 Introduction 115
8.2 Linear and nonlinear elasticity anelastic behavior
8.3 Load–extension curves for non-elastic (plastic) behavior 116
8.4 True stress–strain curves for plastic flow 118
8.5 Plastic work 121
8.6 Tensile testing 121
8.7 Data 122
8.8 The hardness test 123
8.9 Revision of the terms mentioned in this chapter, and some useful relations 126
Chapter 9 Dislocations and yielding in crystals 134
9.1 Introduction 135
9.2 The strength of a perfect crystal 135
9.3 Dislocations in crystals 137
9.4 The force acting on a dislocation 143
9.5 Other properties of dislocations 144
Chapter 10 Strengthening methods, and plasticity of polycrystals 146
10.1 Introduction 147
10.2 Strengthening mechanisms 147
10.3 Solid solution hardening 147
10.4 Precipitate and dispersion strengthening 148
10.5 Work-hardening 150
10.6 The dislocation yield strength 150
10.7 Yield in polycrystals 151
10.8 Final remarks 154
Chapter 11 Continuum aspects of plastic flow 156
11.1 Introduction 157
11.2 The onset of yielding and the shear yield strength, k 157
11.3 Analyzing the hardness test 159
11.4 Plastic instability: necking in tensile loading 160
Chapter 12 Case studies in yield-limited design 168
12.1 Introduction 169
12.2 Case study 1: elastic design-materials for springs 169
12.3 Case study 2: plastic design-materials for a pressure vessel 174
12.4 Case study 3: large-strain plasticity —rolling of metals 175
Part D Fast fracture, brittle fracture and toughness 182
Chapter 13 Fast fracture and toughness 184
13.1 Introduction 185
13.2 Energy criterion for fast fracture 185
13.3 Data for Gc and Kc 190
Chapter 14 Micromechanisms of fast fracture 196
14.1 Introduction 197
14.2 Mechanisms of crack propagation, 1: ductile tearing 197
14.3 Mechanisms of crack propagation, 2: cleavage 199
14.4 Composites, including wood 201
14.5 Avoiding brittle alloys 202
Chapter 15 Case studies in fast fracture 206
15.1 Introduction 207
15.2 Case study 1: fast fracture of an ammonia tank 207
15.3 Case study 2: explosion of a perspex pressure window during hydrostatic testing 210
15.4 Case study 3: cracking of a polyurethane foam jacket on a liquid methane tank 213
15.5 Case study 4: collapse of a wooden balcony railing 217
Chapter 16 Probabilistic fracture of brittle materials 224
16.1 Introduction 225
16.2 The statistics of strength and the Weibull distribution 227
16.3 Case study: cracking of a polyurethane foam jacket on a liquid methane tank 231
Part E Fatigue failure 236
Chapter 17 Fatigue failure 238
17.1 Introduction 239
17.2 Fatigue behavior of uncracked components 239
17.3 Fatigue behavior of cracked components 243
17.4 Fatigue mechanisms 245
Chapter 18 Fatigue design 252
18.1 Introduction 253
18.2 Fatigue data for uncracked components 253
18.3 Stress concentrations 254
18.4 The notch sensitivity factor 255
18.5 Fatigue data for welded joints 256
18.6 Fatigue improvement techniques 257
18.7 Designing-out fatigue cycles 259
18.8 Checking pressure vessels for fatigue cracking 261
Chapter 19 Case studies in fatigue failure 266
19.1 Introduction 267
19.2 Case study 1: high-cycle fatigue of an uncracked component —failure of a pipe organ mechanism 267
19.3 Case study 2: low-cycle fatigue of an uncracked component —failure of a submersible lifting eye 275
19.4 Case study 3: fatigue of a cracked component —the safety of the Stretham engine 279
Part F Creep deformation and fracture 286
Chapter 20 Creep and creep fracture 288
20.1 Introduction 289
20.2 Creep testing and creep curves 292
20.3 Creep relaxation 295
20.4 Creep damage and creep fracture 297
20.5 Creep-resistant materials 298
Chapter 21 Kinetic theory of diffusion 302
21.1 Introduction 303
21.2 Diffusion and Fick’s law 304
21.3 Data for diffusion coefficients 308
21.4 Mechanisms of diffusion 309
Chapter 22 Mechanisms of creep, and creep-resistant materials 314
22.1 Introduction 315
22.2 Creep mechanisms: metals and ceramics 315
22.3 Creep mechanisms: polymers 322
22.4 Selecting materials to resist creep 324
Chapter 23 The turbine blade —a case study in creep-limited design 326
23.1 Introduction 327
23.2 Properties required of a turbine blade 328
23.3 Nickel-based super-alloys 329
23.4 Engineering developments —blade cooling 2 333
23.5 Future developments: metals and metal–matrix composites 334
23.6 Future developments: high-temperature ceramics 336
23.7 Cost effectiveness 337
Part G Oxidation and corrosion 340
Chapter 24 Oxidation of materials 342
24.1 Introduction 343
24.2 The energy of oxidation 343
24.3 Rates of oxidation 344
24.4 Data 347
24.5 Micromechanisms 347
Chapter 25 Case studies in dry oxidation 352
25.1 Introduction 353
25.2 Case study 1: making stainless alloys 353
25.3 Case study 2: protecting turbine blades 354
25.4 Joining operations: a final note 358
Chapter 26 Wet corrosion of materials 360
26.1 Introduction 361
26.2 Wet corrosion 361
26.3 Voltage differences as a driving force for wet oxidation 362
26.4 Rates of wet oxidation 365
26.5 Localized attack 365
Chapter 27 Case studies in wet corrosion 372
27.1 Introduction 373
27.2 Case study 1: the protection of underground pipes 373
27.3 Case study 2: materials for a lightweight factory roof 375
27.4 Case study 3: automobile exhaust systems 378
Part H Friction, abrasion and wear 382
Chapter 28 Friction and wear 384
28.1 Introduction 385
28.2 Friction between materials 385
28.3 Data for coefficients of friction 388
28.4 Lubrication 389
28.5 Wear of materials 390
28.6 Surface and bulk properties 392
Chapter 29 Case studies in friction and wear 396
29.1 Introduction 397
29.2 Case study 1: the design of journal bearings 397
29.3 Case study 2: materials for skis and sledge runners 400
29.4 Case study 3: high-friction rubber 402
Part I Designing with metals, ceramics, polymers and composites 406
Chapter 30 Design with materials 408
30.1 Introduction 409
30.2 Design methodology 411
Chapter 31 Final case study: materials and energy in car design 414
31.1 Introduction 415
31.2 Energy and cars 415
31.3 Ways of achieving energy economy 415
31.4 Material content of a car 417
31.5 Alternative materials 417
31.6 Production methods 423
31.7 Conclusions 425
Appendix 1 Symbols and formulae 426
References 434
Index 436