Chapter 1 Materials: Structure, Properties, and
Performance 1
1.1 Introduction 1
1.2 Monolithic, Composite, and Hierarchical Materials 3
1.3 Structure of Materials 15
1.3.1 Crystal Structures 16
1.3.2 Metals 19
1.3.3 Ceramics 25
1.3.4 Glasses 30
1.3.5 Polymers 31
1.3.6 Liquid Crystals 39
1.3.7 Biological Materials and Biomaterials 40
1.3.8 Porous and Cellular Materials 44
1.3.9 Nano- and Microstructure of Biological Materials 45
1.3.10 The Sponge Spicule: An Example of a Biological Material 56
1.3.11 Active (or Smart) Materials 57
1.3.12 Electronic Materials 58
1.3.13 Nanotechnology 60
1.4 Strength of Real Materials 61
Suggested Reading 64
Exercises 65
Chapter 2 Elasticity and Viscoelasticity 71
2.1 Introduction 71
2.2 Longitudinal Stress and Strain 72
2.3 Strain Energy (or Deformation Energy) Density 77
2.4 Shear Stress and Strain 80
2.5 Poisson’s Ratio 83
2.6 More Complex States of Stress 85
2.7 Graphical Solution of a Biaxial State of Stress: the
Mohr Circle 89
2.8 Pure Shear: Relationship between G and E 95
2.9 Anisotropic Effects 96
2.10 Elastic Properties of Polycrystals 107
2.11 Elastic Properties of Materials 110
2.11.1 Elastic Properties of Metals 111
2.11.2 Elastic Properties of Ceramics 111
2.11.3 Elastic Properties of Polymers 116
2.11.4 Elastic Constants of Unidirectional Fiber Reinforced
Composite 117
2.12 Viscoelasticity 120
2.12.1 Storage and Loss Moduli 124
2.13 Rubber Elasticity 126
2.14 Mooney--Rivlin Equation 131
2.15 Elastic Properties of Biological Materials 134
2.15.1 Blood Vessels 134
2.15.2 Articular Cartilage 137
2.15.3 Mechanical Properties at the Nanometer Level 140
2.16 Elastic Properties of Electronic Materials 143
2.17 Elastic Constants and Bonding 145
Suggested Reading 155
Exercises 155
Chapter 3 Plasticity 161
3.1 Introduction 161
3.2 Plastic Deformation in Tension 163
3.2.1 Tensile Curve Parameters 171
3.2.2 Necking 172
3.2.3 Strain Rate Effects 176
3.3 Plastic Deformation in Compression Testing 183
3.4 The Bauschunger Effect 187
3.5 Plastic Deformation of Polymers 188
3.5.1 Stress--Strain Curves 188
3.5.2 Glassy Polymers 189
3.5.3 Semicrystalline Polymers 190
3.5.4 Viscous Flow 191
3.5.5 Adiabatic Heating 192
3.6 Plastic Deformation of Glasses 193
3.6.1 Microscopic Deformation Mechanism 195
3.6.2 Temperature Dependence and Viscosity 197
3.7 Flow, Yield, and Failure Criteria 199
3.7.1 Maximum-Stress Criterion (Rankine) 200
3.7.2 Maximum-Shear-Stress Criterion (Tresca) 200
3.7.3 Maximum-Distortion-Energy Criterion (von Mises) 201
3.7.4 Graphical Representation and Experimental Verification
of Rankine, Tresca, and von Mises Criteria 201
3.7.5 Failure Criteria for Brittle Materials 205
3.7.6 Yield Criteria for Ductile Polymers 209
3.7.7 Failure Criteria for Composite Materials 211
3.7.8 Yield and Failure Criteria for Other Anisotropic
Materials 213
3.8 Hardness 214
3.8.1 Macroindentation Tests 216
3.8.2 Microindentation Tests 221
3.8.3 Nanoindentation 225
3.9 Formability: Important Parameters 229
3.9.1 Plastic Anisotropy 231
3.9.2 Punch--Stretch Tests and Forming-Limit Curves
(or Keeler--Goodwin Diagrams) 232
3.10 Muscle Force 237
3.11 Mechanical Properties of Some Biological Materials 241
Suggested Reading 245
Exercises 246
Chapter 4 Imperfections: Point and Line Defects 251
4.1 Introduction 251
4.2 Theoretical Shear Strength 252
4.3 Atomic or Electronic Point Defects 254
4.3.1 Equilibrium Concentration of Point Defects 256
4.3.2 Production of Point Defects 259
4.3.3 Effect of Point Defects on Mechanical
Properties 260
4.3.4 Radiation Damage 261
4.3.5 Ion Implantation 265
4.4 Line Defects 266
4.4.1 Experimental Observation of Dislocations 270
4.4.2 Behavior of Dislocations 273
4.4.3 Stress Field Around Dislocations 275
4.4.4 Energy of Dislocations 278
4.4.5 Force Required to Bow a Dislocation 282
4.4.6 Dislocations in Various Structures 284
4.4.7 Dislocations in Ceramics 293
4.4.8 Sources of Dislocations 298
4.4.9 Dislocation Pileups 302
4.4.10 Intersection of Dislocations 304
4.4.11 Deformation Produced by Motion of Dislocations
(Orowan’s Equation) 306
4.4.12 The Peierls--Nabarro Stress 309
4.4.13 The Movement of Dislocations: Temperature and
Strain Rate Effects 310
4.4.14 Dislocations in Electronic Materials 313
Suggested Reading 316
Exercises 317
Chapter 5 Imperfections: Interfacial and Volumetric
Defects 321
5.1 Introduction 321
5.2 Grain Boundaries 321
5.2.1 Tilt and Twist Boundaries 326
5.2.2 Energy of a Grain Boundary 328
5.2.3 Variation of Grain-Boundary Energy with
Misorientation 330
5.2.4 Coincidence Site Lattice (CSL) Boundaries 332
5.2.5 Grain-Boundary Triple Junctions 334
5.2.6 Grain-Boundary Dislocations and Ledges 334
5.2.7 Grain Boundaries as a Packing of Polyhedral Units 336
5.3 Twinning and Twin Boundaries 336
5.3.1 Crystallography and Morphology 337
5.3.2 Mechanical Effects 341
5.4 Grain Boundaries in Plastic Deformation (Grain-size
Strengthening) 345
5.4.1 Hall--Petch Theory 348
5.4.2 Cottrell’s Theory 349
5.4.3 Li’s Theory 350
5.4.4 Meyers--Ashworth Theory 351
5.5 Other Internal Obstacles 353
5.6 Nanocrystalline Materials 355
5.7 Volumetric or Tridimensional Defects 358
5.8 Imperfections in Polymers 361
Suggested Reading 364
Exercises 364
Chapter 6 Geometry of Deformation and
Work-Hardening 369
6.1 Introduction 369
6.2 Geometry of Deformation 373
6.2.1 Stereographic Projections 373
6.2.2 Stress Required for Slip 374
6.2.3 Shear Deformation 380
6.2.4 Slip in Systems and Work-Hardening 381
6.2.5 Independent Slip Systems in Polycrystals 384
6.3 Work-Hardening in Polycrystals 384
6.3.1 Taylor’s Theory 386
6.3.2 Seeger’s Theory 388
6.3.3 Kuhlmann--Wilsdorf’s Theory 388
6.4 Softening Mechanisms 392
6.5 Texture Strengthening 395
Suggested Reading 399
Exercises 399
Chapter 7 Fracture: Macroscopic Aspects 404
7.1 Introduction 404
7.2 Theorectical Tensile Strength 406
7.3 Stress Concentration and Griffith Criterion of
Fracture 409
7.3.1 Stress Concentrations 409
7.3.2 Stress Concentration Factor 409
7.4 Griffith Criterion 416
7.5 Crack Propagation with Plasticity 419
7.6 Linear Elastic Fracture Mechanics 421
7.6.1 Fracture Toughness 422
7.6.2 Hypotheses of LEFM 423
7.6.3 Crack-Tip Separation Modes 423
7.6.4 Stress Field in an Isotropic Material in the Vicinity of a
Crack Tip 424
7.6.5 Details of the Crack-Tip Stress Field in Mode I 425
7.6.6 Plastic-Zone Size Correction 428
7.6.7 Variation in Fracture Toughness with Thickness 431
7.7 Fracture Toughness Parameters 434
7.7.1 Crack Extension Force G 434
7.7.2 Crack Opening Displacement 437
7.7.3 J Integral 440
7.7.4 R Curve 443
7.7.5 Relationships among Different Fracture Toughness
Parameters 444
7.8 Importance of K I c in Practice 445
7.9 Post-Yield Fracture Mechanics 448
7.10 Statistical Analysis of Failure Strength 449
Appendix: Stress Singularity at Crack Tip 458
Suggested Reading 460
Exercises 460
Chapter 8 Fracture: Microscopic Aspects 466
8.1 Introduction 466
8.2 Facture in Metals 468
8.2.1 Crack Nucleation 468
8.2.2 Ductile Fracture 469
8.2.3 Brittle, or Cleavage, Fracture 480
8.3 Facture in Ceramics 487
8.3.1 Microstructural Aspects 487
8.3.2 Effect of Grain Size on Strength of Ceramics 494
8.3.3 Fracture of Ceramics in Tension 496
8.3.4 Fracture in Ceramics Under Compression 499
8.3.5 Thermally Induced Fracture in Ceramics 504
8.4 Fracture in Polymers 507
8.4.1 Brittle Fracture 507
8.4.2 Crazing and Shear Yielding 508
8.4.3 Fracture in Semicrystalline and Crystalline Polymers 512
8.4.4 Toughness of Polymers 513
8.5 Fracture and Toughness of Biological Materials 517
8.6 Facture Mechanism Maps 521
Suggested Reading 521
Exercises 521
Chapter 9 Fracture Testing 525
9.1 Introduction 525
9.2 Impact Testing 525
9.2.1 Charpy Impact Test 526
9.2.2 Drop-Weight Test 529
9.2.3 Instrumented Charpy Impact Test 531
9.3 Plane-Strain Fracture Toughness Test 532
9.4 Crack Opening Displacement Testing 537
9.5 J-Integral Testing 538
9.6 Flexure Test 540
9.6.1 Three-Point Bend Test 541
9.6.2 Four-Point Bending 542
9.6.3 Interlaminar Shear Strength Test 543
9.7 Fracture Toughness Testing of Brittle Materials 545
9.7.1 Chevron Notch Test 547
9.7.2 Indentation Methods for Determining Toughness 549
9.8 Adhesion of Thin Films to Substrates 552
Suggested Reading 553
Exercises 553
Chapter 10 Solid Solution, Precipitation, and
Dispersion Strengthening 558
10.1 Introduction 558
10.2 Solid-Solution Strengthening 559
10.2.1 Elastic Interaction 560
10.2.2 Other Interactions 564
10.3 Mechanical Effects Associated with Solid Solutions 564
10.3.1 Well-Defined Yield Point in the Stress--Strain Curves 565
10.3.2 Plateau in the Stress--Strain Curve and L¨uders Band 566
10.3.3 Strain Aging 567
10.3.4 Serrated Stress--Strain Curve 568
10.3.5 Snoek Effect 569
10.3.6 Blue Brittleness 570
10.4 Precipitation- and Dispersion-Hardening 571
10.5 Dislocation--Precipitate Interaction 579
10.6 Precipitation in Microalloyed Steels 585
10.7 Dual-Phase Steels 590
Suggested Reading 590
Exercises 591
Chapter 11 Martensitic Transformation 594
11.1 Introduction 594
11.2 Structures and Morphologies of Martensite 594
11.3 Strength of Martensite 600
11.4 Mechanical Effects 603
11.5 Shape-Memory Effect 608
11.5.1 Shape-Memory Effect in Polymers 614
11.6 Martensitic Transformation in Ceramics 614
Suggested Reading 618
Exercises 619
Chapter 12 Special Materials: Intermetallics
and Foams 621
12.1 Introduction 621
12.2 Silicides 621
12.3 Ordered Intermetallics 622
12.3.1 Dislocation Structures in Ordered Intermetallics 624
12.3.2 Effect of Ordering on Mechanical Properties 628
12.3.3 Ductility of Intermetallics 634
12.4 Cellular Materials 639
12.4.1 Structure 639
12.4.2 Modeling of the Mechanical Response 639
12.4.3 Comparison of Predictions and
Experimental Results 645
12.4.4 Syntactic Foam 645
12.4.5 Plastic Behavior of Porous Materials 646
Suggested Reading 650
Exercises 650
Chapter 13 Creep and Superplasticity 653
13.1 Introduction 653
13.2 Correlation and Extrapolation Methods 659
13.3 Fundamental Mechanisms Responsible for
Creep 665
13.4 Diffusion Creep 666
13.5 Dislocation (or Power Law) Creep 670
13.6 Dislocation Glide 673
13.7 Grain-Boundary Sliding 675
13.8 Deformation-Mechanism (Weertman--Ashby)
Maps 676
13.9 Creep-Induced Fracture 678
13.10 Heat-Resistant Materials 681
13.11 Creep in Polymers 688
13.12 Diffusion-Related Phenomena in Electronic
Materials 695
13.13 Superplasticity 697
Suggested Reading 705
Exercises 705
Chapter 14 Fatigue 713
14.1 Introduction 713
14.2 Fatigue Parameters and S--N (W¨ohler) Curves 714
14.3 Fatigue Strength or Fatigue Life 716
14.4 Effect of Mean Stress on Fatigue Life 719
14.5 Effect of Frequency 721
14.6 Cumulative Damage and Life Exhaustion 721
14.7 Mechanisms of Fatigue 725
14.7.1 Fatigue Crack Nucleation 725
14.7.2 Fatigue Crack Propagation 730
14.8 Linear Elastic Fracture Mechanics Applied to
Fatigue 735
14.8.1 Fatigue of Biomaterials 744
14.9 Hysteretic Heating in Fatigue 746
14.10 Environmental Effects in Fatigue 748
14.11 Fatigue Crack Closure 748
14.12 The Two-Parameter Approach 749
14.13 The Short-Crack Problem in Fatigue 750
14.14 Fatigue Testing 751
14.14.1 Conventional Fatigue Tests 751
14.14.2 Rotating Bending Machine 751
14.14.3 Statistical Analysis of S--N Curves 753
14.14.4 Nonconventional Fatigue Testing 753
14.14.5 Servohydraulic Machines 755
14.14.6 Low-Cycle Fatigue Tests 756
14.14.7 Fatigue Crack Propagation Testing 757
Suggested Reading 758
Exercises 759
Chapter 15 Composite Materials 765
15.1 Introduction 765
15.2 Types of Composites 765
15.3 Important Reinforcements and Matrix Materials 767
15.3.1 Microstructural Aspects and Importance of the
Matrix 769
15.4 Interfaces in Composites 770
15.4.1 Crystallographic Nature of the Fiber--Matrix
Interface 771
15.4.2 Interfacial Bonding in Composites 772
15.4.3 Interfacial Interactions 773
15.5 Properties of Composites 774
15.5.1 Density and Heat Capacity 775
15.5.2 Elastic Moduli 775
15.5.3 Strength 780
15.5.4 Anisotropic Nature of Fiber Reinforced Composites 783
15.5.5 Aging Response of Matrix in MMCs 785
15.5.6 Toughness 785
15.6 Load Transfer from Matrix to Fiber 788
15.6.1 Fiber and Matrix Elastic 789
15.6.2 Fiber Elastic and Matrix Plastic 792
15.7 Fracture in Composites 794
15.7.1 Single and Multiple Fracture 795
15.7.2 Failure Modes in Composites 796
15.8 Some Fundamental Characteristics of
Composites 799
15.8.1 Heterogeneity 799
15.8.2 Anisotropy 799
15.8.3 Shear Coupling 801
15.8.4 Statistical Variation in Strength 802
15.9 Functionally Graded Materials 803
15.10 Applications 803
15.10.1 Aerospace Applications 803
15.10.2 Nonaerospace Applications 804
15.11 Laminated Composites 806
Suggested Reading 809
Exercises 810
Chapter 16 Environmental Effects 815
16.1 Introduction 815
16.2 Electrochemical Nature of Corrosion in Metals 815
16.2.1 Galvanic Corrosion 816
16.2.2 Uniform Corrosion 817
16.2.3 Crevice corrosion 817
16.2.4 Pitting Corrosion 818
16.2.5 Intergranular Corrosion 818
16.2.6 Selective leaching 819
16.2.7 Erosion-Corrosion 819
16.2.8 Radiation Damage 819
16.2.9 Stress Corrosion 819
16.3 Oxidation of metals 819
16.4 Environmentally Assisted Fracture in Metals 820
16.4.1 Stress Corrosion Cracking (SCC) 820
16.4.2 Hydrogen Damage in Metals 824
16.4.3 Liquid and Solid Metal Embrittlement 830
16.5 Environmental Effects in Polymers 831
16.5.1 Chemical or Solvent Attack 832
16.5.2 Swelling 832
16.5.3 Oxidation 833
16.5.4 Radiation Damage 834
16.5.5 Environmental Crazing 835
16.5.6 Alleviating the Environmental Damage in Polymers 836
16.6 Environmental Effects in Ceramics 836
16.6.1 Oxidation of Ceramics 839
Suggested Reading 840
Exercises 840
Appendixes 843
Index 851
