Mechanical Behavior of Materials

Transcription

1 Mechanical Behavior of Materials Marc Andre Meyers University of California, San Diego Krishan Kumar Chawla University of Alabama at Birmingham m CAMBRIDGE UNIVERSITY PRESS

2 Contents Preface to the First Edition Preface to the Second Edition A Note to the Reader Chapter l.l Materials: Structure, Properties, and Performance Introduction Monolithic, Composite, and Hierarchical Materials Structure of Materials Crystal Structures Metals Ceramics Glasses Polymers Liquid Crystals Biological Materials and Biomaterials Porous and Cellular Materials Nano- and Microstructure of Biological Materials The Sponge Spicule: An Example of a Biological Material Active (or Smart) Materials Electronic Materials Nanotechnology Strength of Real Materials Suggested Reading Exercises page xvii xxi xxiii l l Chapter 2 I Elasticity and Viscoelasticity Introduction Longitudinal Stress and Strain Strain Energy (or Deformation Energy) Density Shear Stress and Strain Poisson's Ratio More Complex States of Stress Graphical Solution of a Biaxial State of Stress: the Mohr Circle Pure Shear: Relationship between G and E Anisotropic Effects Elastic Properties of Polycrystals Elastic Properties of Materials no Elastic Properties of Metals Elastic Properties of Ceramics Elastic Properties of Polymers Elastic Constants of Unidirectional Fiber Reinforced Composite 117

3 CONTENTS 2.12 Viscoelasticity Storage and Loss Moduli Rubber Elasticity Mooney-Rivlin Equation Elastic Properties of Biological Materials Blood Vessels Articular Cartilage Mechanical Properties at the Nanometer Level Elastic Properties of Electronic Materials Elastic Constants and Bonding 145 Suggested Reading 155 Exercises 155 Chapter 3 I Plasticity i6i 3.1 Introduction Plastic Deformation in Tension Tensile Curve Parameters Necking Strain Rate Effects Plastic Deformation in Compression Testing The Bauschunger Effect Plastic Deformation of Polymers Stress-Strain Curves Glassy Polymers Semicrystalline Polymers Viscous Flow Adiabatic Heating Plastic Deformation of Glasses Microscopic Deformation Mechanism Temperature Dependence and Viscosity Flow, Yield, and Failure Criteria Maximum-Stress Criterion (Rankine) Maximum-Shear-Stress Criterion (Tresca) Maximum-Distortion-Energy Criterion (von Mises) Graphical Representation and Experimental Verification of Rankine, Tresca, and von Mises Criteria Failure Criteria for Brittle Materials Yield Criteria for Ductile Polymers Failure Criteria for Composite Materials Yield and Failure Criteria for Other Anisotropic Materials Hardness Macroindentation Tests Microindentation Tests Nanoindentation Formability: Important Parameters Plastic Anisotropy 231

4 CONTENTS Punch-Stretch Tests and Forming-Limit Curves (or Keeler-Goodwin Diagrams) Muscle Force Mechanical Properties of Some Biological Materials 241 Suggested Reading 245 Exercises 246 Chapter 4 I Imperfections: Point and Line Defects Introduction Theoretical Shear Strength Atomic or Electronic Point Defects Equilibrium Concentration of Point Defects Production of Point Defects Effect of Point Defects on Mechanical Properties Radiation Damage Ion Implantation Line Defects Experimental Observation of Dislocations Behavior of Dislocations Stress Field Around Dislocations Energy of Dislocations Force Required to Bow a Dislocation Dislocations in Various Structures Dislocations in Ceramics Sources of Dislocations Dislocation Pileups Intersection of Dislocations Deformation Produced by Motion of Dislocations (Orowan's Equation) The Peierls-Nabarro Stress The Movement of Dislocations: Temperature and Strain Rate Effects Dislocations in Electronic Materials 313 Suggested Reading 316 Exercises 317 Chapter 5 Imperfections: Interfacial and Volumetric Defects Introduction Grain Boundaries Tilt and Twist Boundaries Energy of a Grain Boundary Variation of Grain-Boundary Energy with Misorientation Coincidence Site Lattice (CSL) Boundaries Grain-Boundary Triple Junctions 334

5 5.2.6 Gram-Boundary Dislocations and Ledges Grain Boundaries as a Packing of Polyhedral Units Twinning and Twin Boundaries Crystallography and Morphology Mechanical Effects Grain Boundaries in Plastic Deformation (Grain-size Strengthening) Hall-Petch Theory Cottrell's Theory Li's Theory Meyers-Ashworth Theory Other Internal Obstacles Nanocrystalline Materials Volumetric or Tridimensional Defects Imperfections in Polymers 361 Suggested Reading 364 Exercises 364 Chapter 6 Geometry of Deformation and Work-Hardening Introduction Geometry of Deformation Stereographic Projections Stress Required for Slip Shear Deformation Slip in Systems and Work-Hardening Independent Slip Systems in Polycrystals Work-Hardening in Polycrystals Taylor's Theory Seeger's Theory Kuhlmann-Wilsdorfs Theory Softening Mechanisms Texture Strengthening 395 Suggested Reading 399 Exercises 399 Chapter 7 I Fracture: Macroscopic Aspects Introduction Theorectical Tensile Strength Stress Concentration and Griffith Criterion of Fracture Stress Concentrations Stress Concentration Factor Griffith Criterion Crack Propagation with Plasticity Linear Elastic Fracture Mechanics Fracture Toughness 422

6 CONTENTS Hypotheses of LEFM Crack-Tip Separation Modes Stress Field in an Isotropic Material in the Vicinity of a Crack Tip Details of the Crack-Tip Stress Field in Mode I Plastic-Zone Size Correction Variation in Fracture Toughness with Thickness Fracture Toughness Parameters Crack Extension Force G Crack Opening Displacement J Integral R Curve Relationships among Different Fracture Toughness Parameters Importance of К Ic in Practice Post-Yield Fracture Mechanics Statistical Analysis of Failure Strength 449 Appendix: Stress Singularity at Crack Tip 458 Suggested Reading 460 Exercises 460 Chapter 8 I Fracture: Microscopic Aspects Introduction Facture in Metals Crack Nucleation Ductile Fracture Brittle, or Cleavage, Fracture Facture in Ceramics Microstructural Aspects Effect of Grain Size on Strength of Ceramics Fracture of Ceramics in Tension Fracture in Ceramics Under Compression Thermally Induced Fracture in Ceramics Fracture in Polymers Brittle Fracture Crazing and Shear Yielding Fracture in Semicrystalline and Crystalline Polymers Toughness of Polymers Fracture and Toughness of Biological Materials Facture Mechanism Maps 521 Suggested Reading 521 Exercises 521 Chapter 9 I Fracture Testing Introduction Impact Testing Charpy Impact Test 526

7 xii CONTENTS Drop-Weight Test Instrumented Charpy Impact Test Plane-Strain Fracture Toughness Test Crack Opening Displacement Testing J-Integral Testing Flexure Test Three-Point Bend Test Four-Point Bending Interlaminar Shear Strength Test Fracture Toughness Testing of Brittle Materials Chevron Notch Test Indentation Methods for Determining Toughness Adhesion of Thin Films to Substrates 552 Suggested Reading 553 Exercises 553 Chapter 10 Solid Solution, Precipitation, and Dispersion Strengthening Introduction Solid-Solution Strengthening Elastic Interaction Other Interactions Mechanical Effects Associated with Solid Solutions Well-Defined Yield Point in the Stress-Strain Curves Plateau in the Stress-Strain Curve and Lüders Band Strain Aging Serrated Stress-Strain Curve Snoek Effect Blue Brittleness Precipitation- and Dispersion-Hardening Dislocation-Precipitate Interaction Precipitation in Microalloyed Steels Dual-Phase Steels 590 Suggested Reading 590 Exercises 591 Chapter I I I Martensitic Transformation Introduction Structures and Morphologies of Martensite Strength of Martensite Mechanical Effects Shape-Memory Effect Shape-Memory Effect in Polymers Martensitic Transformation in Ceramics 614 Suggested Reading 618 Exercises 619

8 CONTENTS Chapter 12 Special Materials: Intermetallics and Foams Introduction Suicides Ordered Intermetallics Dislocation Structures in Ordered Intermetallics Effect of Ordering on Mechanical Properties Ductility of Intermetallics Cellular Materials Structure Modeling of the Mechanical Response Comparison of Predictions and Experimental Results Syntactic Foam Plastic Behavior of Porous Materials Suggested Reading Exercises Chapter 13 1 Creep and Superplasticity Introduction Correlation and Extrapolation Methods Fundamental Mechanisms Responsible for Creep Diffusion Creep Dislocation (or Power Law) Creep Dislocation Glide Grain-Boundary Sliding Deformation-Mechanism (Weertman-Ashby) Maps Creep-Induced Fracture Heat-Resistant Materials Creep in Polymers Diffusion-Related Phenomena in Electronic Materials Superplasticity 697 Suggested Reading 705 Exercises 705 Chapter 14 I Fatigue Introduction Fatigue Parameters and S-N (Wöhler) Curves Fatigue Strength or Fatigue Life Effect of Mean Stress on Fatigue Life Effect of Frequency Cumulative Damage and Life Exhaustion Mechanisms of Fatigue '

9 Fatigue Crack Nucleation Fatigue Crack Propagation Linear Elastic Fracture Mechanics Applied to Fatigue Fatigue of Biomaterials Hysteretic Heating in Fatigue Environmental Effects in Fatigue Fatigue Crack Closure The Two-Parameter Approach The Short-Crack Problem in Fatigue Fatigue Testing Conventional Fatigue Tests Rotating Bending Machine Statistical Analysis of S-N Curves Nonconventional Fatigue Testing Servohydraulic Machines Low-Cycle Fatigue Tests Fatigue Crack Propagation Testing 757 Suggested Reading 758 Exercises 759 Chapter 15 I Composite Materials Introduction Types of Composites Important Reinforcements and Matrix Materials Microstructural Aspects and Importance of the Matrix Interfaces in Composites Crystallographic Nature of the Fiber-Matrix Interface Interfacial Bonding in Composites Interfacial Interactions Properties of Composites Density and Heat Capacity Elastic Moduli Strength Anisotropic Nature of Fiber Reinforced Composites Aging Response of Matrix in MMCs Toughness Load Transfer from Matrix to Fiber Fiber and Matrix Elastic Fiber Elastic and Matrix Plastic Fracture in Composites Single and Multiple Fracture Failure Modes in Composites Some Fundamental Characteristics of Composites Heterogeneity 799

10 CONTENTS Anisotropy Shear Coupling Statistical Variation in Strength Functionally Graded Materials Applications Aerospace Applications Nonaerospace Applications Laminated Composites 806 Suggested Reading 809 Exercises 810 Chapter 16 I Environmental Effects Introduction Electrochemical Nature of Corrosion in Metals Galvanic Corrosion Uniform Corrosion Crevice corrosion Pitting Corrosion mtergranular Corrosion Selective leaching Erosion-Corrosion Radiation Damage Stress Corrosion Oxidation of metals Environmentally Assisted Fracture in Metals Stress Corrosion Cracking (SCC) Hydrogen Damage in Metals Liquid and Solid Metal Embrittlement Environmental Effects in Polymers Chemical or Solvent Attack Swelling Oxidation Radiation Damage Environmental Crazing Alleviating the Environmental Damage in Polymers Environmental Effects in Ceramics Oxidation of Ceramics 839 Suggested Reading 840 Exercises 840 Appendixes 843 Index 851