Metals and Materials

Metals and Materials: Science, Processes, Applications aims to present the science of materials in a readable and concise form that leads naturally to an explanation of the ways in which materials are processed and applied. The science of metals, or physical metallurgy, has developed naturally into the wider and more diverse discipline of materials science. The study of metals and alloys still forms a large and important part of this relatively new discipline, but it’s common to find that fundamental principles and concepts of physical metallurgy can be adapted to explain the behavior of a variety of non-metallic materials. As an aid to fully study this discipline, each chapter has been supplemented with a list of specialized references. These references include images and diagrams that illustrate the subtleties of materials, such as micrographs of grain structures and fine-scale defects, phase diagrams for metals and ceramics, electron diffraction patterns revealing atomic arrangements, specific property diagrams correlating the behavior of different materials, and slip vector diagrams for deforming crystals.

Throughout this book, sufficient background and theory is provided to assist students in answering questions about a large part of a typical degree course in materials science and engineering. Some sections provide a background or point of entry for postgraduate studies and courses.

Preface

1 The Structure and Bonding of Atoms

1.1 The Realm of Materials Science

1.2 The Free Atom

1.2.1 The Four Electron Quantum Numbers

1.2.2 Nomenclature for Electronic States

1.3 The Periodic Table

1.4 Interatomic Bonding in Materials

1.5 Bonding and Energy Levels

2 Atomic Arrangements in Materials

2.1 The Concept of Ordering

2.2 Crystal Lattices and Structures

2.3 Crystal Directions and Planes

2.4 Stereographic Projection

2.5 Selected Crystal Structures

2.5.1 Pure Metals

2.5.2 Diamond and Graphite

2.5.3 Coordination in Ionic Crystals

2.5.4 AB-Type Compounds

2.5.5 Silica

2.5.6 Alumina

2.5.7 Complex Oxides

2.5.8 Silicates

2.6 Inorganic Glasses

2.6.1 Network Structures in Glasses

2.6.2 Classification of Constituent Oxides

2.7 Polymeric Structures

2.7.1 Thermoplastics

2.7.2 Elastomers

2.7.3 Thermosets

2.7.4 Crystallinity in Polymers

3 Structural Phases; Their Formation and Transitions

3.1 Crystallization from the Melt

3.1.1 Freezing of a Pure Metal

3.1.2 Plane-Front and Dendritic Solidification at a Cooled Surface

3.1.3 Forms of Cast Structure

3.1.4 Gas Porosity and Segregation

3.1.5 Directional Solidification

3.1.6 Production of Metallic Single Crystals for Research

3.2 Principles of Applications of Phase Diagrams

3.2.1 The Concept of a Phase

3.2.2 The Phase Rule

3.2.3 Stability of Phases

3.2.4 Two-Phase Equilibria

3.2.5 Three-Phase Equilibria and Reactions

3.2.6 Intermediate Phases

3.2.7 Limitations of Phase Diagrams

3.2.8 Some Key Phase Diagrams

3.2.9 Ternary Phase Diagrams

3.3 Principles of Alloy Theory

3.3.1 Primary Substitutional Solid Solutions

3.3.2 Interstitial Solid Solutions

3.3.3 Types of Intermediate Phase

3.3.4 Order-Disorder Phenomena

3.4 The Mechanism of Phase Changes

3.4.1 Kinetic Considerations

3.4.2 Homogeneous Nucleation

3.4.3 Heterogeneous Nucleation

3.4.4 Nucleation in Solids

4 Defects in Solids

4.1 Types of Imperfection

4.2 Point Defects

4.2.1 Point Defects in Metals

4.2.2 Point Defects in Non-metallic Crystals

4.2.3 Irradiation of Solids

4.2.4 Point Defect Concentration and Annealing

4.3 Line Defects

4.3.1 Concept of a Dislocation

4.3.2 Edge and Screw Dislocations

4.3.3 The Burgers Vector

4.3.4 Mechanisms of Slip and Climb

4.3.5 Strain Energy Associated with Dislocations

4.3.6 Dislocations in Ionic Structures

4.4 Planar Defects

4.4.1 Grain Boundaries

4.4.2 Twin Boundaries

4.4.3 Extended Dislocations in Closepacked Crystals

4.5 Volume Defects

4.5.1 Void Formation and Annealing

4.5.2 Irradiation and Voiding

4.5.3 Voiding and Fracture

4.6 Defect Behavior in Some Real Materials

4.6.1 Dislocation Vector Diagrams and the Thompson Tetrahedron

4.6.2 Dislocations and Stacking Faults in fcc Structures

4.6.3 Dislocations and Stacking Faults in cph Structures

4.6.4 Dislocations and Stacking Faults in bcc Structures

4.6.5 Dislocations and Stacking Faults in Ordered Structures

4.6.6 Dislocations and Stacking Faults in Ceramics

4.6.7 Defects in Crystalline Polymers

4.6.8 Defects in Glasses

4.7 Stability of Defects

4.7.1 Dislocation Loops

4.7.2 Voids

4.7.3 Nuclear Irradiation Effects

5 The Characterization of Materials

5.1 Tools of Characterization

5.2 Light Microscopy

5.2.1 Basic Principles

5.2.2 Selected Microscopical Techniques

5.3 X-Ray Diffraction Analysis

5.3.1 Production and Absorption of X-Rays

5.3.2 Diffraction of X-Rays by Crystals

5.3.3 X-Ray Diffraction Methods

5.3.4 Typical Interpretative Procedures for Diffraction Patterns

5.4 Analytical Electron Microscopy

5.4.1 Interaction of an Electron Beam with a Solid

5.4.2 The Transmission Electron Microscope (TEM)

5.4.3 The Scanning Electron Microscope

5.4.4 Theoretical Aspects of TEM

5.4.5 Chemical Microanalysis

5.4.6 Electron Energy Loss Spectroscopy (EELS)

5.4.7 Auger Electron Spectroscopy (AES)

5.5 Observation of Defects

5.5.1 Etch Pitting

5.5.2 Dislocation Decoration

5.5.3 Dislocation Strain Contrast in TEM

5.5.4 Contrast from Crystals

5.5.5 Imaging of Dislocations

5.5.6 Imaging of Stacking Faults

5.5.7 Application of Dynamical Theory

5.5.8 Weak-Beam Microscopy

5.6 Specialized Bombardment Techniques

5.6.1 Neutron Diffraction

5.6.2 Synchrotron Radiation Studies

5.6.3 Secondary Ion Mass Spectrometry (SIMS)

5.7 Thermal Analysis

5.7.1 General Capabilities of Thermal Analysis

5.7.2 Thermogravimetric Analysis

5.7.3 Differential Thermal Analysis

5.7.4 Differential Scanning Calorimetry

6 The Physical Properties of Materials

6.1 Introduction

6.2 Density

6.3 Thermal Properties

6.3.1 Thermal Expansion

6.3.2 Specific Heat Capacity

6.3.3 The Specific Heat Curve and Transformations

6.3.4 Free Energy of Transformation

6.4 Diffusion

6.4.1 Diffusion Laws

6.4.2 Mechanisms of Diffusion

6.4.3 Factors Affecting Diffusion

6.5 Anelasticity and Internal Friction

6.6 Ordering in Alloys

6.6.1 Long-Range and Short-Range Order

6.6.2 Detection of Ordering

6.6.3 Influence of Ordering upon Properties

6.7 Electrical Properties

6.7.1 Electrical Conductivity

6.7.2 Semiconductors

6.7.3 Superconductivity

6.7.4 Oxide Superconductors

6.8 Magnetic Properties

6.8.1 Magnetic Susceptibility

6.8.2 Diamagnetism and Paramagnetism

6.8.3 Ferromagnetism

6.8.4 Magnetic Alloys

6.8.5 Anti-Ferromagnetism and Ferrimagnetism

6.9 Dielectric Materials

6.9.1 Polarization

6.9.2 Capacitors and Insulators

6.9.3 Piezoelectric Materials

6.9.4 Pyroelectric and Ferroelectric Materials

6.10 Optical Properties

6.10.1 Reflection, Absorption and Transmission Effects

6.10.2 Optical Fibers

6.10.3 Lasers

6.10.4 Ceramic 'Windows'

6.10.5 Electro-optic Ceramics

7 Mechanical Behavior of Materials

7.1 Mechanical Testing Procedures

7.1.1 Introduction

7.1.2 The Tensile Test

7.1.3 Indentation Hardness Testing

7.1.4 Impact Testing

7.1.5 Creep Testing

7.1.6 Fatigue Testing

7.1.7 Testing of Ceramics

7.2 Elastic Deformation

7.2.1 Elastic Deformation of Metals

7.2.2 Elastic Deformation of Ceramics

7.3 Plastic Deformation

7.3.1 Slip and Twinning

7.3.2 Resolved Shear Stress

7.3.3 Relation of Slip to Crystal Structure

7.3.4 Law of Critical Resolved Shear Stress

7.3.5 Multiple Slip

7.3.6 Relation between Work-Hardening and Slip

7.4 Dislocation Behavior during Plastic Deformation

7.4.1 Dislocation Mobility

7.4.2 Variation of Yield Stress with Temperature and Strain Rate

7.4.3 Dislocation Source Operation

7.4.4 Discontinuous Yielding

7.4.5 Yield Points and Crystal Structure

7.4.6 Discontinuous Yielding in Ordered Alloys

7.4.7 Solute-Dislocation Interaction

7.4.8 Dislocation Locking and Temperature

7.4.9 Inhomogeneity Interaction

7.4.10 Kinetics of Strain-Ageing

7.4.11 Influence of Grain Boundaries on Plasticity

7.4.12 Superplasticity

7.5 Mechanical Twinning

7.5.1 Crystallography of Twinning

7.5.2 Nucleation and Growth of Twins

7.5.3 Effect of Impurities on Twinning

7.5.4 Effect of Prestrain on Twinning

7.5.5 Dislocation Mechanism of Twinning

7.5.6 Twinning and Fracture

7.6 Strengthening and Hardening Mechanisms

7.6.1 Point Defect Hardening

7.6.2 Work-Hardening

7.6.3 Development of Preferred Orientation

7.7 Macroscopic Plasticity

7.7.1 Tresca and Von Mises Criteria

7.7.2 Effective Stress and Strain

7.8 Annealing

7.8.1 General Effects of Annealing

7.8.2 Recovery

7.8.3 Recrystallization

7.8.4 Grain Growth

7.8.5 Annealing Twins

7.8.6 Recrystallization Textures

7.9 Metallic Creep

7.9.1 Transient and Steady-State Creep

7.9.2 Grain Boundary Contribution to Creep

7.9.3 Tertiary Creep and Fracture

7.9.4 Creep-Resistant Alloy Design

7.10 Deformation Mechanism Maps

7.11 Metallic Fatigue

7.11.1 Nature of Fatigue Failure

7.11.2 Engineering Aspects of Fatigue

7.11.3 Structural Changes Accompanying Fatigue

7.11.4 Crack Formation and Fatigue Failure

7.11.5 Fatigue at Elevated Temperatures

8 Strengthening and Toughening

8.1 Introduction

8.2 Strengthening of Non-ferrous Alloys by Heat-Treatment

8.2.1 Precipitation-hardening of Al-Cu Alloys

8.2.2 Precipitation-hardening of Al-Ag Alloys

8.2.3 Mechanisms of Precipitation-hardening

8.2.4 Vacancies and Precipitation

8.2.5 Duplex Ageing

8.2.6 Particle-Coarsening

8.2.7 Spinodal Decomposition

8.3 Strengthening of Steels by Heat-Treatment

8.3.1 Time-Temperature-Transformation Diagrams

8.3.2 Austenite-Pearlite Transformation

8.3.3 Austenite-Martensite Transformation

8.3.4 Austenite-Bainite Transformation

8.3.5 Tempering of Martensite

8.3.6 Thermo-Mechanical Treatments

8.4 Fracture and Toughness

8.4.1 Griffith Micro-Crack Criterion

8.4.2 Fracture Toughness

8.4.3 Cleavage and the Ductile-Brittle Transition

8.4.4 Factors Affecting Brittleness of Steels

8.4.5 Hydrogen Embrittlement of Steels

8.4.6 Intergranular Fracture

8.4.7 Ductile Failure

8.4.8 Rupture

8.4.9 Voiding and Fracture at Elevated Temperatures

8.4.10 Fracture Mechanism Maps

8.4.11 Crack Growth under Fatigue Conditions

9 Modern Alloy Developments

9.1 Introduction

9.2 Commercial Steels

9.2.1 Plain Carbon Steels

9.2.2 Alloy Steels

9.2.3 Maraging Steels

9.2.4 High-Strength Low-Alloy (HSLA) Steels

9.2.5 Dual-Phase (DP) Steels

9.2.6 Mechanically Alloyed (MA) Steels

9.2.7 Designation of Steels

9.3 Cast Irons

9.4 Superalloys

9.4.1 Basic Alloying Features

9.4.2 Nickel-Based Superalloy Development

9.4.3 Dispersion-Hardened Superalloys

9.5 Titanium Alloys

9.5.1 Basic Alloying and Heat-Treatment Features

9.5.2 Commercial Titanium Alloys

9.5.3 Processing of Titanium Alloys

9.6 Structural Intermetallic Compounds

9.6.1 General Properties of Intermetallic Compounds

9.6.2 Nickel Aluminides

9.6.3 Titanium Aluminides

9.6.4 Other Intermetallic Compounds

9.7 Aluminum Alloys

9.7.1 Designation of Aluminum Alloys

9.7.2 Applications of Aluminum Alloys

9.7.3 Aluminum-Lithium Alloys

9.7.4 Processing Developments

10 Ceramics and Glasses

10.1 Classification of Ceramics

10.2 General Properties of Ceramics

10.3 Production of Ceramic Powders

10.4 Selected Engineering Ceramics

10.4.1 Alumina

10.4.2 From Silicon Nitride to Sialons

10.4.3 Zirconia

10.4.4 Glass-Ceramics

10.4.5 Silicon Carbide

10.4.6 Carbon

10.5 Aspects of Glass Technology

10.5.1 Viscous Deformation of Glass

10.5.2 Some Special Glasses

10.5.3 Toughened and Laminated Glasses

10.6 The Time-Dependency of Strength in Ceramics and Glasses

11 Plastics and Composites

11.1 Utilization of Polymeric Materials

11.1.1 Introduction

11.1.2 Mechanical Aspects of Tg

11.1.3 The Role of Additives

11.1.4 Some Applications of Important Plastics

11.1.5 Management of Waste Plastics

11.2 Behavior of Plastics during Processing

11.2.1 Cold-Drawing and Crazing

11.2.2 Processing Methods for Thermoplastics

11.2.3 Production of Thermosets

11.2.4 Viscous Aspects of Melt Behavior

11.2.5 Elastic Aspects of Melt Behavior

11.2.6 Flow Defects

11.3 Fiber-Reinforced Composite Materials

11.3.1 Introduction to Basic Structural Principles

11.3.2 Types of Fiber-Reinforced Composite

12 Corrosion and Surface Engineering

12.1 The Engineering Importance of Surfaces

12.2 Metallic Corrosion

12.2.1 Oxidation at High Temperatures

12.2.2 Aqueous Corrosion

12.3 Surface Engineering

12.3.1 The Coating and Modification of Surfaces

12.3.2 Surface Coating by Vapor Deposition

12.3.3 Surface Coating by Particle Bombardment

12.3.4 Surface Modification with High-Energy Beams

Appendices

1 SI Units

2 Conversion Factors, Constants and Physical Data

Figure References

Index