Part Ⅰ High Temperature Deformation 3
1 Creep Behavior of Materials 3
1.1 Creep Curve 3
1.2 Stress and Temperature Dependence of Creep Rate 4
1.3 Stacking Fault Energy Effect 9
1.4 Grain Size Effect 10
References 12
2 Evolution of Dislocation Substructures During Creep 14
2.1 Parameters of Dislocation Substructures and Their Measurements 14
2.2 Evolution of Dislocation Substructure during Creep 16
2.3 Dislocation Substructure of Steady State Creep 19
2.4 Inhomogeneous Dislocation Substructure and Long-Range Internal Stress 22
References 26
3 Dislocation Motion at Elevated Temperatures 28
3.1 Thermally Activated Glide of Dislocation 28
3.2 Measurement of Internal Stress 31
3.3 Climb of Dislocations 33
3.4 Basic Equations of Recovery Creep 36
3.5 Mechanisms of Recovery 37
References 38
4 Recovery-Creep Theories of Pure Metals 40
4.1 Introduction 40
4.2 Weertman Model 41
4.3 Models Considering Sub-Boundary 42
4.4 Models Based on Dislocation Network 47
4.5 Creep Model Based on the Motion of Jogged Screw Dislocation 50
4.6 Summary of Recovery Creep Models 52
4.7 Soft and Hard Region Composite Model 53
4.8 Harper-Dorn Creep 58
References 66
5 Creep of Solid Solution Alloys 69
5.1 Interaction Between Dislocation and Solute Atom 69
5.2 Creep Behavior of Solid Solution Alloys 72
5.3 Viscous Glide Velocity of Dislocations 76
5.4 Creep Controlled by Viscous Glide of Dislocations 78
References 81
6 Creep of Second Phase Particles Strengthened Materials 83
6.1 Introduction 83
6.2 Arzt-Ashby Model 85
6.3 Creep Model Based on Attractive Particle-Dislocation Interaction 88
6.4 Interaction of Dislocation with Localized Particles 91
6.5 Mechanisms of Particle Strengthening 93
6.6 Grain Boundary Precipitation Strengthening 96
References 100
7 Creep of Particulates Reinforced Composite Material 102
7.1 Creep Behavior of Particulates Reinforced Aluminium Matrix Composites 102
7.2 Determination of Threshold Stress 104
7.3 Creep Mechanisms and Role of Reinforcement Phase 105
References 110
8 High Temperature Deformation of Intermetallic Compounds 111
8.1 Crystal Structures,Dislocations and Planar Defects 111
8.2 Dislocation Core Structure 115
8.3 Slip Systems and Flow Stresses of Intermetallic Compounds 120
8.4 Creep of Intermetallic Compounds 126
8.5 Creep of Compound-Based ODS Alloys 133
References 136
9 Diffusional Creep 139
9.1 Theory on Diffusional Creep 139
9.2 Accommodation of Diffusional Creep:Grain Boundary Sliding 142
9.3 Diffusional Creep Controlled by Boundary Reaction 144
9.4 Experimental Evidences of Diffusional Creep 149
References 151
10 Superplasticity 154
10.1 Stability of Deformation 154
10.2 General Characteristics of Superplasticity 155
10.3 Microstructure Characteristics of Superplasticity 158
10.4 Grain Boundary Behaviors in Superplastic Deformation 160
10.5 Mechanism of Superplastic Deformation 161
10.6 The maximum Strain Rate for Superplasticity 167
References 170
11 Mechanisms of Grain Boundary Sliding 172
11.1 Introduction 172
11.2 Intrinsic Grain Boundary Sliding 172
11.3 Extrinsic Grain Boundary Sliding 174
References 180
12 Multiaxial Creep Models 182
12.1 Uniaxial Creep Models 182
12.2 Mutiaxial Creep Models 183
12.3 Mutiaxial Steady State Creep Model 185
12.4 Stress Relaxation by Creep 186
References 187
Part Ⅱ High Temperature Fracture 191
13 Nucleation of Creep Cavity 191
13.1 Introduction 191
13.2 Nucleation Sites of Cavity 192
13.3 Theory of Cavity Nucleation 195
13.4 Cavity Nucleation Rate 196
References 197
14 Creep Embrittlement by Segregation of Impurities 199
14.1 Nickel and Nickel-Base Superalloys 199
14.2 Low-Alloy Steels 202
References 205
15 Diffusional Growth of Creep Cavities 206
15.1 Chemical Potential of Vacancies 206
15.2 Hull-Rimmer Model for Cavity Growth 207
15.3 Speight-Harris Model for Cavity Growth 211
15.4 The role of Surface Diffusion 213
References 215
16 Cavity Growth by Coupled Diffusion and Creep 217
16.1 Monkman-Grant Relation 217
16.2 Beer-Speight Model 218
16.3 Edward-Ashby Model 221
16.4 Chen-Argon model 222
16.5 Cocks-Ashby Model 225
References 228
17 Constrained Growth of Creep Cavities 230
17.1 Introduction 230
17.2 Rice Model 230
17.3 Raj-Ghosh Model 233
17.4 Cocks-Ashby Model 235
References 238
18 Nucleation and Growth of Wedge-Type Microcracks 239
18.1 Introduction 239
18.2 Nucleation of Wedge-Type Cracks 240
18.3 The Propagation of Wedge-Type Cracks 242
18.4 Crack Growth by Cavitation 244
References 246
19 Creep Crack Growth 247
19.1 Crack-Tip Stress Fields in Elastoplastic Body 247
19.2 Stress Field at Steady-State-Creep Crack Tip 251
19.3 The Crack Tip Stress Fields in Transition Period 255
19.4 Vitek Model for Creep Crack Tip Fields 259
19.5 The Influence of Creep Threshold Stress 262
19.6 The Experimental Results for Creep Crack Growth 264
References 272
20 Creep Damage Mechanics 274
20.1 Introduction to the Damage Mechanics 274
20.2 Damage Variable and Effective Stress 275
20.3 Kachanov Creep Damage Theory 277
20.4 Rabotnov Creep Damage Theory 279
20.5 Three-Dimensional Creep Damage Theory 281
References 283
21 Creep Damage Physics 285
21.1 Introduction 285
21.2 Loss of External Section 286
21.3 Loss of Internal Section 287
21.4 Degradation of Microstructure 289
21.5 Damage by Oxidation 295
References 296
22 Prediction of Creep Rupture Life 297
22.1 Extrapolation Methods of Creep Rupture Life 297
22.2 θ Projection Method 300
22.3 Maruyama Parameter 302
22.4 Reliability of Prediction for Creep Rupture Property 304
References 306
23 Creep-Fatigue Interaction 307
23.1 Creep Fatigue Waveforms 307
23.2 Creep-Fatigue Failure Maps 307
23.3 Holding Time Effects on Creep-Fatigue Lifetime 310
23.4 Fracture Mechanics of Creep Fatigue Crack Growth 312
References 317
24 Prediction of Creep-Fatigue Life 319
24.1 Linear Damage Accumulation Rule 319
24.2 Strain Range Partitioning 321
24.3 Damage Mechanics Method 324
24.4 Damage Function Method 326
24.5 Empirical Methods 328
References 329
25 Environmental Damage at High Temperature 330
25.1 Oxidation 330
25.2 Hot Corrosion 338
25.3 Carburization 342
References 347
Appendix A 349
Appendix B 357
Index 359