Mechanical Behaviour and Testing of Materials

590 Pages·2011·289.171 MB·English

by  A. K. Bhargava

MECHANICAL BEHAVIOUR AND TESTING OF MATERIALS

MECHANICAL BEHAVIOUR
and
TESTING OF MATERIALS
A.K. BHARGAVA and C.P. SHARMA
Department of Metallurgical and Materials Engineering
Malaviya National Institute of Technology
Jaipur
PHI Learning
[;)u1ffiG@ llilwlBG@dl
Delhi-110092
2014
MECHANICAL BEHAVIOUR AND TESTING OF MATERIALS
A.K. Bhargava and C.P. Sharma
© 2011 by PHI Learning Private Limited, Delhi. All rights reserved. No part of this book may be
reproduced in any form, by mimeograph or any other means, without permission in writing from the
publisher.
ISBN-978-81-203-4250-7
The export rights of this book are vested solely with the publisher.
Second Printing August, 2014
Published by Asoke K. Ghosh, PHI Learning Private Limited, Rimjhim House, 111, Patparganj
Industrial Estate, Delhi-110092 and Printed by Mohan Makhijani at Rekha Printers Private Limited,
New Delhi-110020.
To
The Almighty
and
Our Parents

Contents
Preface xv
Acknowledgements xvii
Nomenclature xix
1. Nature of Materials 1-31
1.1 Introduction 1
1.2 Interatomic and Intermolecular Bonding 7
1.3 Classification and Combination of Elements JO
1.4 Atomic Arrangement 12
1.5 Engineering Materials 14
1.5.1 Steel 14
1.5.2 Cast Irons 18
1.5.3 Aluminium and Its Alloys 20
1.5.4 Magnesium and Its Alloys 20
1.5.5 Titanium and Its Alloys 20
1.5.6 Copper and Its Alloys 21
1.5.7 Nickel and Its Alloys 22
1.5.8 Cobalt and Its Alloys 24
1.5.9 Ceramic Materials 25
1.5.10 Polymeric Materials 26
1.5.11 Composite Materials 30
2. Crystal Imperfections 32-44
2.1 Introduction 32
vii
viii Contents
2.2 Imperfections 37
2.2.1 Point Imperfections 37
2.2.2 Line Imperfections 40
2.2.3 Surface Imperfections 41
2.2.4 Volume Imperfections 44
3. Mechanical Properties 45-56
3.1 Introduction 45
3.2 Static Mechanical Properties 47
3.2.1 Tensile Strength 47
3.2.2 Compressive Strength 49
3.2.3 Ductility 49
3.2.4 Malleability 50
3.2.5 Stiffness 50
3.2.6 Toughness 51
3.2.7 Creep Strength 52
3.2.8 Hardness 52
3.3 Dynamic Mechanical Properties 53
3.3.1 Impact Strength 53
3.3.2 Fatigue Strength 53
3.3.3 Hardness 54
3.4 Structure-Mechanical Property Relationship 54
4. Dislocation Theory 57-103
4.1 Introduction 57
4.2 The Shear Strength of Ideal and Real Crystals 59
4.3 Geometry of Dislocations 60
4.3.1 Edge Dislocation 61
4.3.2 Screw Dislocation 63
4.4 Burgers Vector, Burgers Circuit and Dislocation Loop 64
4.5 Movement of Dislocations 67
4.5.1 Concept of Slip 67
4.5.2 Dislocations and Slip 70
4.5.3 Slip Plane 72
4.5.4 Cross-Slip 72
4.5.5 Dislocation Climb 73
4.6 Elastic Properties of Dislocations 74
4.6.1 Stress Field and Energy of a Dislocation 74
4.6.2 Forces on Dislocations 77
4.6.3 Line Tension 78
4.7 Forces between Dislocations 80
4.8 Unit Dislocations and Partial Dislocations 84
4.8.1 Dislocations in FCC, BCC and HCP Crystals 85
4.8.2 Dislocations and their Reaction in FCC Crystals 86
Contents ix
4.8.3 Frank Partial Dislocations 91
4.8.4 Lamer-Cottrell Dislocations 92
4.9 Peierls-Nabarro Stress and Dislocation Width 94
4.10 Dislocation Multiplication 96
4.11 Dislocation Intersection 98
4.12 Dislocations in Ceramics 101
5. Deformation of Metals 104-138
5.1 Introduction 104
5.2 Elastic Deformation 104
5.2.1 Significance of Elastic Modulus 106
5.3 Plastic Deformation 107
5.3.1 Deformation by Slip 107
5.3.2 Type of Loading for Plastic Deformation 109
5.3.3 Potential Slip Planes and Directions in Crystals 110
5.3.4 Critical Resolved Shear Stress 113
5.3.5 Strain Hardening in Single Crystal 119
5.3.6 Structural Changes in Cold Worked Polycrystalline
Metals and Alloys 123
5.3.7 Annealing of Cold Worked Metals 128
5.4 Deformation by Twinning 134
5.5 Deformation Behaviour in Ceramics 136
5.6 Deformation Behaviour in Polymers 136
6. Strengthening Mechanisms in Materials 139-205
6.1 Introduction 139
6.2 Grain Boundary Strengthening 141
6.3 Solid Solution Strengthening 145
6.4 Second Phase Particle Strengthening 153
6.4.1 Precipitation Hardening 154
6.4.2 Dispersion Hardening 168
6.5 Strain Hardening 169
6.5.1 Properties Affected by Strain Hardening 171
6.5.2 Industrial Importance of Strain Hardening 172
6.6 Martensitic Strengthening 174
6.7 Composite Strengthening 175
6.7.1 Fibre Strengthened Composites 176
6.7.2 Dispersion Strengthened Composites 188
6.7.3 Particle-Strengthened (or Simply Particulate) Composites 190
6.8 Strengthening of Plastics 190
6.8.1 Strengthening by High Average Molecular Weight 191
6.8.2 Strengthening by Crystallinity 193
6.8.3 Strengthening by Bulky Pendant Atomic Group 195