ISBN: 3540679065
TITLE: Formability of Metallic Materials
AUTHOR: Banabic, Bunge, Phlandt, Tekkaya
TOC:

1 Introduction. Elements of Crystal Plasticity
K. Phlandt 1
1.1 Survey 2
1.2 Concepts 2
1.3 Crystal Structure and Crystal Defects 5
1.4 Plastic Deformation 9
1.4.1 Gliding of Dislocations 9
1.4.2 Mechanical Twinning 14
1.4.3 Sharp Yield Point and Strain Aging 14
1.5 Recovery and Recrystallization 17
1.5.1 Overview 17
1.5.2 Recovery 18
1.5.3 Recrystallization 9
1.5.4 Changes of Structure during Hot Forming 20
References to Chapter 1 22
2 Crystallographic Texture and Plastic Anisotropy
H.-J. Bunge 23
2.1 Structure of Polycrystalline Materials 26
2.2 Definition of Crystallographic Texture 27
2.2.1 Crystal Orientation 28
2.3 Experimental Determination of Textures 30
2.4 Texture and Properties of Materials 33
3.5 Plasticity of Polycrystalline Materials 36
2.5.1 The Taylor Model (Full-Constraints) 40
2.5.2 Special Plasticity Parameters 47
2.5.3 Plasticity of Cubic Metals 50
2.5.4 Deformation Hardening 51
2.5.5 Plasticity of Macroscopic Bodies 54
2.6 Parametrization of the Texture Function 54
2.7 Other Modes of Plasticity 56
References to Chapter 2 57
3 Formability Testing
K. Phlandt 61
3.1 Introduction 63
3.2 Determination of Flow Curves 63
3.2.1 Tensile Test 64
3.2.2 Upsetting Cylindrical Specimens 67
3.2.3 Plane Strain Upsetting Test 71
3.2.4 Upsetting Test at Elevated Temperatures 75
3.2.5 Torsion Test 76
3.2.6 Special Methods 84
3.2.7 Flow Curves of Sheet Metal 84
3.3 Plastic Anisotropy of Round Bars, Wire and Tubes 86
3.3.1 Introduction 86
3.3.2 General Terminology 88
3.3.3 Recommended Experimental Procedures 89
3.3.4 Metal Forming Processes and Relevant Parameters 93
3.4 Transferability of Results 96
3.4.1 Basic Problem 96
3.4.2 Uncertainty of Experimentally Determined Flow Curves 97
3.5 Determining Forming Limits in Bulk Metal Forming 101
3.5.1 Concepts 101
3.5.2 The Term "Ductility" 103
3.5.3 The Forming Limit 104
3.5.4 Process Simulating Testing Methods 107
References to Chapter 3 108
4 Anisotropy of Sheet Metal
D. Banabic 119
4.1 Definition of the Anisotropy Coefficient 122
4.2 Yield Criteria for Isotropic Materials 123
4.2.1 Tresca Yield Criterion 125
4.2.2 Huber-Mises-Hencky Yield Criterion 127
4.2.3 Drucker Yield Criterion 128
4.2.4 Hosford Yield Criterion 129
4.3 Quadratic Yield Criteria 129
4.3.1 Hill 1948 Yield Criterion 130
4.4 Non-quadratic Yield Criteria 135
4.4.1 Hill 1979 Yield Criterion 136
4.4.2 Bassani Yield Criterion 139
4.4.3 Hosford 1979 Yield Criterion 139
4.4.4 Early Yield Criteria by Barlat 141
4.4.5 Hill 1990 Yield Criterion 144
4.4.6 Hill 1993 Yield Criterion 147
4.4.7 Barlat 1991 Yield Criterion 150
4.4.8 Karafillis-Boyce Yield Criterion 152
4.4.9 The Yield Criteria by Barlat 1994 and 1996 157
4.4.10 Other Nonquadratic Yield Criteria 160
4.5 Yield Criteria Expressed in Polar Coordinates 163
4.5.1 Budiansky Yield Criterion 163
4.5.2 Ferron Yield Criterion 164
4.6 Other Yield Criteria 166
4.4 Recommentations for the Practice 166
References to Chapter 4 168
5 Forming Limits of Sheet Metal
D. Banabic 173
5.1 Introduction 173
5.2 Methods for Evaluating Sheet Metal Formability 179
5.2.1 Methods Based on Simulating Tests 179
5.2.2 Limit Dome Height Method 187
5.2.3 Methods Based on Mechanical Tests (Intrinsic Methods) 188
5.3 Forming Limit Diagram 189
5.3.1 Definition. History 189
5.3.2 Main Tests Used to Determine the FLD 192
5.3.3 Factors Influencing Forming Limit Diagrams 198
5.3.4 Theoretical Models for Calculating Forming Limit Diagrams 204
5.3.5 Use of Forming Limits Diagrams in Industrial Practice 205
References to Chapter 5 209
6 Workpiece Properties after Metal Forming
K. Phlandt 215
6.1 Survey 215
6.1.1 Material Behavior during Machining after Metal Forming 216
6.1.2 Material Properties after Homogeneous Deformation 217
6.2 Strain Distribution in Workpieces 217
6.2.1 Visioplasticity Method 218
6.2.2 Hardness Distribution 219
6.3 Deformation-Induced Residual Stresses 221
6.3.1 Cold Bulk Metal Forming 222
6.3.2 Sheet Metal Forming 229
6.4 Corrosive Behavior of Sheet Metal Components 230
6.4.1 Survey 230
6.4.2 Austenitic Stainless Steels 231
6.4.3 CuZn Alloys 233
6.5 Fatigue Behavior of Extruded Components 235
6.5.1 Introduction 235
6.5.2 Ingot Steels 238
6.5.3 P/M Steels 242
6.5.4 Aluminum Alloy 244
6.5.5 Concluding Remarks 245
References to Chapter 6 245
7 Simulation of Metal Forming
A.E. Tekkaya 251
7.1 Introduction 252
7.2 Elements of Continuum Mechanics 253
7.2.1 Nonlinear Kinematics of Deformation 253
7.2.2 Axiom of Objectivity 257
7.3 Rigid-Plastic Explicit Methods 258
7.3.1 Rigid-Plastic Material Law 259
7.3.2 Markov's Variational Statement 260
7.3.3 Discretization: Penalty Factor Approach 261
7.3.4 Discretization: Lagrangian Multiplier Approach 263
7.3.5 Numerical Solution: Direct Iterative Method 265
7.3.6 Numerical Solution: Newton- (Raphson) Method 268
7.3.7 Static Explicit Solution Scheme 270
7.3.8 Thermomechanical Analysis 274
7.4 Elasto-Plastic Implicit Methods 276
7.4.1 Goveming Variational Statement 276
7.4.2 Stress Update 279
7.5 Elasto-Plastic Explicit Methods 282
7.5.1 Introduction 282
7.5.2 Finite Element Equation of Motion 283
7.5.3 Computational Issues 284
7.5.4 Dynamic Relaxation 287
7.6 Applications 287
7.6.1 Introduction 287
7.6.2 Element Types 291
7.6.3 Meshing Issues 292
7.6.4 Bulk Forming Applications 293
7.6.5 Sheet Forming Applications 296
References to Chapter 7 298
Appendix 1: Tables
K. Phlandt 303
A.1.1 Standards for Formability Testing 303
A.1.2 Comparative Designations of Materials 306
A.1.3 Mechanical Properties of Selected Steels 307
A.1.4 Conversion Factors of Units 308
Appendix 2: Flow Curves of Common Metals 309
K. Phlandt
A.2.1 Experimentally Determined Flow Curves 309
A.2.2 Analytical Approximation 311
References to Appendix 2 314
Appendix 3: Theoretical Models of the FLD's
D. Banabic 317
A.3.1 Models Based on the Necking Theory 318
A.3.2 Models Based on the Theory of Sheet-Nonhomogeneity 320
A.3.3 Linear Perturbation Theory 324
A. 3.4 Semiempirical Models 325
References to Appendix 3 326
Index 329
END
