accumulation of outer layer of billet in discard 322
adaptive remeshing 223
adhesion of lubricant to workpiece 146
advantage and disadvantage of backward extrusion 24, 324
allotropic behavior of steel 118
analogy, between stress and strain 62, 66
anisotropy
factor of 442
measurement 443
normal 443
planar 443
in sheet-metal 442
in worked metals 7
area reduction 77
aspect ratio in
cylinder compression 81
plain strain compression 35
asperity 141
plastification 142
atoms, packing of 3
austenite 118
average
length strain 78
pressure in frictionless compression 81
axi-symmetric FEM model 225
back-pull in wiredrawing 398
backward cup extrusion
effective strain rate distribution 286
effective strain distribution 288
FEA of process 285–301
balanced biaxial stretching 438
barreling of cylinder in compression 108
bearing in wiredrawing dies 399
bend allowance 447
bending 28
of sheet-metal 439
biaxial stretching 438
billet 22
removal without deformation 350
blank holder 27, 444
blanking 30
conventional 30
fine 30
blister defect 323, 331
bloom 22
bottleneck in forming 12
boundary
film lubrication 146, 147–149
lubrication 146
boundary conditions in FEA 224
breakdown of material 127
due to cracking 134
breakdown of
cast microstructure 4
lubricant film 13
Bridgman's
assumptions in necking analysis 243
correction factor in tensile testing 105
theoretical analysis of 104
buckling 19
in deep-drawing 444
bulging in
cylinder compression 108
wire drawing 417, 418
bulk metal forming 9, 18
burp cycle 332
calibration draw 395
capstan 396
casting
defect formation 5
material loss 5
cast iron 3
cavity filling 268
cementite flakes 2, 3
center bursts 421
center zone in plain strain compression 41
cermets 398
material model 115
chevron cracks 421
growth in FEA 423
circle grid analysis 435, 436
to determine strains 68
classification system
extrudability of Al-alloys 335
extrusion processes 10
metal forming 9, 18
shapes of Al-profiles 334
shapes of forgings 271, 272
subdivision metal forming processes 10
types of metal flow in extrusion 326
clay, deformation of 1
deformation mechanism 3
clean cut in shearing 30
cleaning, of surfaces 144
closed die forging 20–21
die filling in 302
example of laboratory process 302
FEA of 302–316
optimized process 279
Cockroft-Latham failure criterion 134
coefficient of friction 142
cogging 20
coiling of wire 396
cold drawing of wire 27
cold forming
cold working by wiredrawing 27
to gain high strength 7
temperature range of 118
vs. hot forming 34
complex strain path in sheet-metal forming 437
compression
axial 87
homogeneous slab 87
retarded stroke for constant strain rate 108
compression testing, advantages over tensile testing 95
compressive stress
on inside of bend 439
in wiredrawing die 398
cone angle in wiredrawing 400
confinement of air in extrusion material 332
constancy of volume 63
deviation from rule of 64
constitutive equation
definition 115
in cold forming 118
general expression 117
in hot forming 122
including microstructural mechanisms 122
metals in general 115–118
contact angle in rolling 370
contact area
apparent area 141
in compression 107
real area 141
contact conditions between
billet and container, in extrusion 351
roll and workpiece, in rolling 365
contact mechanisms, workpiece-die 143
contact pressure against die as process parameter 14
contact pressure against die in
cylinder compression 230–233
deep drawing 27
from the slab method 373
light slab rolling 380
normal slab rolling 387
normal wiredrawing 427
strip rolling 391
wiredrawing 400
contact zone against
die in closed-die forging 302–305
contamination
as subsurface defect in extrusion 330
of surfaces 144
continuous casting 22
continuum
mechanics 2
medium 2
converging channel of wiredrawing die 399
conversion coating 300
cooling
effects 159, 162
of plate against die 163–164
copper wiredrawing 414
Coulomb friction
model 140–142
validity of model 142
cracking 127
due to lamination 8
in cylinder bulge 134, 136
in shear 136
transverse cracking in extrusion 134
critical blank size in deep-drawing 444
crystals, aggregate of 3
cup forming by deep drawing 27
curve fitting
applied for the flow stress 118
determination of constants 119
cutting 10
cylinder compression
basic mechanics of test method 106
compression velocity 106
deformation in corner of bulge 252
deformations in compression test 253–254
dies applied in test 106
experimental set-up 106
FEA of test 229
flow curve in test 107
with friction 108
friction effects 199
friction measurement using pins 153–154
frictionless compression 1
homogeneous compression 107, 251
principal stress in frictionless case 210
reduced friction in test 109
strain rate field in frictionless case 210
as technological test 93, 95
velocity field in frictionless case 209
damage parameter in
light slab rolling pass 381
normal slab rolling pass 386
normal wiredrawing from FEA 427
plain strain compression 47
small reduction, large cone angle wiredrawing 421
strip rolling pass 392
wiredrawing 421
damage parameter, critical value 134
dead zone in
backward cup extrusion 286
cylinder compression 109
extrusion 183, 322
plain strain compression 41
strip rolling 390
deep drawing 27
applied tooling 27
fracture in 28
of rectangular cup 440
of round cup 440
of sheet-metal 439
wrinkling 28
defects
avoid defects because of economy 14
blisters in extrusion 323
of critical size 130
in forging 279
hot tearing in Al-extrusion 159
DEFORM®-code 223
FEM-approach used 224
deformation
comparison of compression and tension 59
over edge of plain strain compression die 44
effect of varying clearance in shearing 260–263
elastic 1
energy 160
fluctuations in wiredrawing 417
homogeneity in cylinder compression 108
homogeneity in extrusion seam 238
of inhomogeneous nature 2
macroscopic 2
mapping of 2
mechanism of 4
microscopic 3
multiplication of deformation crosses 46
near punch in backward cup extrusion 296
patterns in wiredrawing 431
of permanent character 116
plastic 1
simple measure of total deformation 77
deformation analysis 40–46
deformation characteristics of extruded rod 192
deformation cross in
normal wiredrawing 424
plain strain compression 44
strip rolling 390
cylinder compression 253
deformation from
deformed grid pattern 182
effective strain distribution 43
effective strain rate distribution 43
grid pattern in backward extrusion 290–292
strain rate distribution in wiredrawing 425
velocity field 85–87
deformation in
backward cup extrusion 286
deep-drawing 440
extruded rod from grid pattern 192–195
extruded rod 361
extrusion 24
extrusion billet from strain rate 362
front end of extruded rod 322
hot closed die forging 310–314
light pass slab rolling 377, 379
neck from circle pattern 247
necking section 243
neck in tensile test 103
normal pass slab rolling 383
plain strain compression test 40–46
shearing 30, 259
sheet-metal forming 438
strip rolling 389
wiredrawing, low reduction – large angle 416
wiredrawing, normal drawing geometry 425
degree of reduction 79
deletion of FEM-mesh to model cracking 422
Δ-parameter 81
in plain strain compression 36
in rolling 376
in strip rolling 393
in wiredrawing 403, 414
in Wistreich's wiredrawing experiments 414
diamond in wiredrawing die 398
die bridge in extrusion 333
die cavity 20
die filling in closed-die forging 277, 302
die geometry, characteristic parameters 400
die-life, influenced by fatigue 142
die orifice 23
dies
in metal forming 13
wear of 13
die splitting force in
strip drawing 149
wiredrawing 401, 414
diffuse necking 131
dimensional stability in drawing 395
direct contact between surfaces 144
directionally oriented microstructure 442
discard
in extrusion 321, 323
removal of 324
dislocation 3
density 3
movement 3
dislocation networks in cold and hot forming 122
displacement components 86
division processes, shearing 30
draft in rolling 383
drawing
as continuous process 396
as discontinuous process 396
of strip 64
unit in wiredrawing machine 397
wheel 396
drawing cell in drawing machine 398
drawing conditions in normal wiredrawing 424
ductility 128
increase through metal working 7
earing
factors influencing earing 447
phenomenon in deep-drawing 446
ease of working 128
economy in metal forming 14
edges for cutting 30
effective strain distribution, plain strain compression 43
effective strain rate distribution, plain strain compression 43
elastic
layer in bend 440
zone 191
elastic deformation
of dies 53
in tensile test 102
elasticity theory 53
elastic-plastic
materials 116
emissitivity 164
emptying diagram
in backward cup extrusion 296
concept 195
in extrusion made by FEA 359
emptying line
longitudinal 199
transverse 197
energy consumption
definition of 69
in extrusion 325
friction energy 406
for homogeneous deformation 405
for inhomogeneous deformation 407–409
total in wiredrawing 405, 409
energy dissipation 69
entrance into roll gap 376
equation to find friction in split die experiment 401
Erichsen-test 438
Eulerian description 222
eutectic phases, as contamination in extrusion 324
excessive stresses in sheet-metal forming 441
experiments to validate FEM analysis 35
explicit FEM-method 222
exponent of strain hardening 118
extrudability of
Al 25
Al-alloys 335
extrudate 320
extruded profiles 23
extrusion 23–26, 320
advantage of direct over indirect 24
backward process 23
billet 23
classification of processes 10
complex hollow profile extrusion 25
container 23
of copper and brass 24
defect 331
direct process 23
division into subprocesses 326, 347
flow of outer layer of billet 24
force 337
force against container wall 338
forward process 23
friction force 341
homogeneous deformation force 341
hot extrusion of Al 322
hot lubricated 25
indirect process 23
inhomogeneous deformation force 342
limitations in backward extrusion 24
of light metals 24
load in backward extrusion 325
metal flow in direct and indirect process 24
in multi-hole dies 24
peripheral billet layer 24
practice in forward extrusion 323
pressure 337
pressure welding 25
punch 23
ram 23
residue 321, 323
seam welds 26
shell extrusion 24
of steel 25
tooling in porthole die extrusion 25
total force 337, 343
welding 26
welding, FEM-model of 233–238
welding chamber 25
failure
criteria 134
catastrophic 130
FEA
correction of flow curve 245–246
to determine thermal effects 168–173
in general 220
general importance in metal forming 221
graphical presentation of results 229
results as parameter distribution 229
FEM-codes
development of 221
to model metal forming 223
FEM model, 2D
backward Al-extrusion 358–362
backward cup extrusion 285–301
cylinder compression 136, 200–201, 229–233, 250–253
extrusion welding 237–238, 333
forward Al-extrusion 352–357
forward extrusion, subprocesses 347–349
plain strain compression 225, 226
shearing, deformations in sheared layer 257–263
shearing, to find K and n 264–265
slab rolling pass 376–393
tensile test, formability consideration 130–131
tensile testing, risk of cracking 135–136
tensile testing, stress conditions in neck 243–246
wiredrawing 415–431
FEM model, 3D
closed-die forging 302–316
cylinder compression 253
extrusion welding 233–237
plain strain compression 37–50
tensile testing, necking 247
FEM-modeling, in general 220
FEM-solver 224
ferrite 2, 118
finished product 13
finishing die 274
finite difference method 204
finite element analysis (FEA) 34
validation of 35
finite element method (FEM) 34
finite elements 221
flash 21
formation of 4
flash gap 277
characteristic geometrical conditions 281
common designs 281
design rules in closed-die forging 280
flash less forging 20
flat rolling 22
flat-faced die, in extrusion 322
FLD-diagram 130, 441
flow criteria, the von Mises and Tresca criterion 111
flow criterion, correctness of 38
flow curve 116
determination in cold forming 107
determination curve in hot forming 107
from tensile test 102
true and nominal curve 103
flow direction of outer layer of billet in extrusion 331
flow formulation 222
flow patterns in extrusion 326–328
flow rule of Lévy-Mises 73
flow stress
of Al-alloys in bending experiments
in cold, warm, and hot forming 115, 116
from compression test 107
of copper wire 117, 416
general function 118
to get right metal flow in Al-extrusion 353
mean value of in wiredrawing 405
parameter influence 116
as process parameter 14
from shearing test 263–265
temperature dependence 117
variation due to microstructure 118
flow types in extrusion 190
foil 442
folds 279
force
on the roll 367
total force in wiredrawing 399
forgeability 269
of different metals 270
forging
as a requirement 7
avoiding unsound grain flow 8
as nonstationary process 85
deformation in hot closed die forging 310–314
design of multistep series 274–276
design principles 276
design to avoid defects 280
to improve fatigue resistance 8
mass distribution principle in 276
optimum temperature 269
stock 274
typical multi-step forging sequence 275
forgings
complexity of 271
shapes difficulty to forge 272
formability 127
to avoid defect formation 14
improvements in deep-drawing 442
limits 441
of metals in deep-drawing 446
parameter in deep-drawing 445
parameter in stretch forming 445
forming under
compressive stress 9, 18
tensile stress 9, 18
fracture 127
elongation 94, 103
in forgings due to defects 280
in shear 138
strain 94, 103
free forming 19
friction
in backward cup extrusion 300
Causing load increase in bending 216
determination in plain strain compression 37
dry friction 144–145
effects in metal forming 139
effects on flow curve from compression 254
energy dissipation 162
factor 143
force 141
force as process parameter 14
heating 161
hill 208
influence on forming load 139
measurement in forming 149–155
measurement in wiredrawing 400
measurement using pins 152
shear stress 142
shear stress in wiredrawing 400
from surface ring pattern 199
friction coefficient 142
value, boundary film lubrication 148
value, hydrodynamic lubrication 147
frictionless compression, average pressure vs. Δ 81
friction models 140
comparison of models 143
implementation of in FEM-codes 229
full separation of contact surfaces 144
fusion welding 26
general extrusion, part of extrusion process 349
generic deformation modes in sheet-metal forming 439
Gleeble simulator 96
testing 35
working principle of simulator 96
grain
boundaries 2
as crystals 3
flow in forgings 8
graphical tools in FEM analysis 224
grid pattern analysis
in compression experiment 249
deformation of grid elements 41
in extrusion welding 237
in FEA of compression 250
in shearing experiment 259
grid pattern distortions in
backward Al-extrusion 359
light slab rolling pass 379
normal slab rolling pass 385
normal wiredrawing 426
strip rolling pass 390
wiredrawing, small reduction, large cone angle 418
grid pattern technique 2, 181
advantage of pattern from pins 184
appearance of grid 182
in backward extrusion of Al cup 290–292, 357
contrast materials 184
deformed pattern in extrudate 183, 188
identification of grid elements 186, 189
intrinsic pattern 184
making pattern from contrast pins 184, 185
notation to identify grid lines 186
parting agent to avoid welding 182
perfect deformed pattern in Al-extrusion 187
in plain strain compression 36
scratched patterns 181
hardness testing
contact pressure 82
indenter 93
test method 93
heat
capacity 160
effects 159
transfer coefficient 163
height strain 80
height-to-diameter-ratio, in cylinder compression 80
Hensel-Spittel constitutive equation 118
high-strain-rate zone in
normal wiredrawing 424
plain strain compression 45
rolling 377
wiredrawing 416
hollow
extrusion dies 25
profile extrusion 333
homogeneous deformation in cylinder compression 109
Hooke's law 73, 115
hot forming
temperature range of 118
vs. cold forming 34
hot tearing 159
mechanism in Al-extrusion 178
hottest spot in Al-extrusion die 178
hydra-wedge for multistep compression 98
hydrostatic extrusion 322
ideal work method 204
impact extrusion 21
backward method 21
forward method 21
implicit FEM-method 222
inclusions, of MnS 7
incremental strain from velocity field 85
index notation for stress tensor 55
inferior properties due to lamination 8
ingot 19
inhomogeneous deformation in
cylinder compression 109
light slab rolling pass 379
normal slab rolling pass 383
normal wiredrawing from FEA 425
strip rolling pass 390
inserts, used in wiredrawing dies 398
instability 18
causing necking 131
criterion for start of necking 104
in high slender cylinder compression 95
in tensile testing 103
integrity of materials 128
interface between die and workpiece 13
intrinsic ductility 128
inverse modeling 37
determine flow curve in tensile testing 246
determine friction in backward cup extrusion 299–301
inverse parameter identification to
determine friction 37
get right localized shear 37
inverse segregation in extrusion billet 324
inward compression, part of extrusion process 349
isothermal FEM model 225
isotropic materials 63
isotropy of sheet-metal 442
joining
of metal streams in extrusion 25
processes 9
Lagrangian description 222
lamination 8
in extrusion 321
laps 279
largest principal stress in normal wiredrawing 427
layered appearance 8
length
strain, transformed to reduction of area 79
Lévy-Mises flow rule 73
limiting draw ratio, LDR in deep-drawing 444
load-stroke curve
cylinder compression 107
extrusion 325
forging 277
optimized curve in closed-die forging 315
localized necking 94, 131
logs of Al 24
loss of material 4
low-cycle fatigue of dies 142
lubricant 13
thick lubricant film through wedge effect 147
viscosity of 147
lubricated extrusion 322
lubrication
boundary film 147
boundary films in 148
in drawing 397
in forging 271
glass in extrusion 25
hydrodynamic 146–147
mechanisms 144
Ludvig's law 119
machines, used in metal forming 13
machining
material removal 6
macro etching 8
malleability 128, 269
manufacturing
cheapest process 7
classification system 9
comparison of processes 4
methods 1
of rod and wire 26
mass production 6
material
failure in forming 127
flow phenomena in wiredrawing 431
inhomogeneity on micro-scale 3
loss 4
loss reduction in forging 314
models implemented in FEA 227
removal 4
matte surface, hydrodynamic lubrication 146
maximum principal stress to explain chevron cracking 423
mean through thickness strain rate in rolling 370
measurement techniques applied in Al-extrusion 175
mechanical properties
improved by forming 4
of a material 103
of finished product 15
mechanical working to gain high strength 7
mechanism of chevron crack formation 422
metal flow analysis 181
metal flow in
direct compared to indirect extrusion 195
Al-extrusion from FEA 354
extrusion 326–328
in FEA, validated experimentally 354
idealized 2D extrusion welding 235
unlubricated direct extrusion 189–191
metal forming
characteristics of 4
classification system 9
definition of 1
overview of processes 10
requirements for sound process economy 13
simulator 93
stable process, requirement 7, 13
metal removal
processes 9
by shearing 30
metallic bond formed in extrusion welding 334
mixed lubrication 149
modeling techniques
description of methods 220
goal for performing engineering analysis 219
model material 181
Mohr's circle 56
sign convention 57
for strains 62
multistep
forming 19, 98
wiredrawing 398
near net shaping 20
neck
average axial stress in 105
as defect in sheet metal forming 103
formation 18
growth in tensile testing 102
radius of curvature in 105
tri-axial stress state in 104
necking
failure in sheet-metal forming 130, 441
FEM model of 130
instability in 94
localized 131
in tensile testing 94, 102, 130
neutral plane in
bending 439
plane strain compression 34
neutral point in rolling 367
node in FEM-mesh 221
nominal strain from
circle grid analysis 437
tensile test 102
nominal stress from tensile test 101
nonstationary processes 84
normal stress, definition of 53
Northon-Hoff constitutive equation 118
numerical modeling 220
open die forging 19–20
optimum die cone angle in wiredrawing 411
origin inside billet of surface layer of rod 195
outer billet layer, outflow of in extrusion 329–331
out of the plane stretching 438
overfolding 279
in extrusion 329
overloading of tools 53
oxide layer 144
oxide layer on
Al 145
Al, oxide effect on emissitivity 165
Cu 145
particle paths 85
in wiredrawing 429
pearlite 2
peripheral billet skin, flow of in extrusion 328
physical
in big WUMSI simulator 98
metal forming simulation 35
modeling 37, 96–101
modeling techniques 220
simulation 92, 96
pinching, part of extrusion process 349
pin measurement of friction 149
pipe, defect in extrusion 181, 331
plain strain compression
applied to sheet metals 109
average contact pressure in 111
effective strain in 111
effective stress in 111
inside channel-shaped die 95
maintain ideal conditions 35, 109, 111
mechanics of ideal test 110
relative contact pressure in 82
technological test 34, 93, 95
test to mimic rolling 109
thermal effects in test 227
thickness strain in 111
with overhanging platens 96
plain strain
tensile test 436
FEM model 225
plastic
constraint in plain strain compression 110
straining 4
yield 70, 116
plasticity theory 53
plastic zone 12
geometrical shape of 81
in backward cup extrusion 286
in normal wiredrawing 424
in wiredrawing 400, 416
plastification 4, 53
of forming dies 142
plate material 442
pointing of wire or rod before drawing 396
point-tracking, in FEA to trace metal flow 361
polymers
deformation mechanism 3
deformation of 1
porthole die extrusion 25, 333
postprocessing results in plain strain compression 40–50
postextrusion deformation, avoiding phenomenon 351
postprocessing 224
power law
cold forming 119
hot forming 122
power of deformation 70
Prandtl-Reuss equations 222
precision forging 20
predeformation of back end of billet 193, 328
preforming in forging 274
preform optimization in closed-die forging 314
preprocessing 224
prescribed circumference of extruded profile 24
pressure
through boundary interface 141
distribution against die in wiredrawing 420
pad 321
peak in friction hill in wiredrawing 420
peak in friction hill in rolling 380
welding 26
welding in extrusion 334
welding onto the die 13
primary
dead zone in extrusion 191, 356
deformation zone (extrusion) 190, 322, 356
shear zone in extrusion 356
principal strains from circle grid analysis 437
principal stress
definition of 55
distribution of parameter in neck 243
largest value in light slab rolling pass 382
largest value in normal slab rolling pass 386
in plain strain compression 48
problem areas, in forming 12
process parameters 14
importance of 14
in metal forming 14
product in forming 13
production processes
characteristics of 6
select the best process 6
production in low numbers 6
productivity, high level of 13
profile drawing 396
projected length of arc of contact 368, 372
punch load, friction effects in backward cup extrusion 296
pure shear in torsion test 111
pyrometry 159, 164
radial compression, part of the extrusion process 349
radiation of heat 159
Ramberg-Osgoods equation 119
recovery 122
recrystalization 7, 122
redefined strain in compression 80
reduction ratio
definition of 77
in extrusion 79
reduction in
percent 79
wiredrawing 399, 403
remeshing 223
to get good FEM mesh 223
removal of material 4
results of FEM-analysis 224
retention of peripheral layer of billet 191, 327
rigid-plastic materials 116
rigid zone 42
ring compression test 149–152
measurement technique 149
ring proportions 151
riser, in casting 5
rod, drawing of 27, 395
roll
force equation 367
forging 275
gap 366
rolling
force 367
problem areas 12
processes 22–23
schedule 23
roughening rolling mill 22
sawing to make workpiece 7
scaling defect in extrusion 330
scalping operation in extrusion 324
scraping of ram against container 193
scraping
of ram head against container wall 328
part of extrusion process 349
scratching
at rear end of container 351
part of extrusion process 349
secondary
dead zone 191
deformation zone 190, 322
shear zone, in extrusion 356
section rolling 22
security components 6, 302
seizure of workpiece in rolling 376
selection of forward or backward extrusion method 324
semifinished products 22
shape change, permanent type 53
shaping methods 1
shear
band formation in plain strain compression 42
cracking 136
cross in cylinder compression 136
flow stress 71, 143
fracture in sheet-metal forming 441
layer of moderate shear 42
localization 138
strain in wiredrawing 426
zone in Al-extrusion 183, 191
shearing 10, 30
part of extrusion process 348
as technological test 257
FEM model of process 257
to make workpiece 7
shear stress
at an interface, as process parameter 14
definition of 53
maximum value of 56
positive or negative stress 55
sheet material 442
sheet metal forming 9, 18, 27–29
shiny surface appearance in thin-film lubrication 146
shut lap 280
Siebel's drawing force equation 403
simulation 224
simulative tests in sheet-metal forming 438
slab 22
slab method 205
applied in cylinder compression 209–212
applied in extrusion 338
applied in plain strain compression 205
applied in rolling 373
die pressure in cylinder compression 212
die pressure in plane strain compression 208
the force balance 207
force in cylinder compression 212
force in plane strain compression 208
general assumptions 206
slab rolling 376
description normal pass 383
sliding
contact zone at rear end of billet 351
against die, plane strain compression 161
friction 145
slip
in rolling 367
of wire against capstan 399
slip line field method 204
slow flowing zone in extrusion 329
slug in backward cup extrusion 285
soft annealed condition, formability of material in 131
soft annealing 27
in wiredrawing production 397
of workpiece in backward cup extrusion 285
softening, strain-induced 136
solid formulation 222
spinning 29
tooling in 29
split billet technique 182
split die principle, to measure friction 400
springback
because of elasticity 440
compensation by coning of bend 450
compensation by overbending 449
compensation by stretch bending 450
compensation methods 449
phenomenon of 447
prediction in FEA 227
ratio, definition of 448
ratio, experimental data for metals 448
reduced by stretch forming 29, 440
why difficult to predict 449
stable drawing as requirement 399
stagnant zone in
cylinder compression 109
plain strain compression 41, 45
in wiredrawing 425
static remeshing 223
stationary processes 84
steel
C-Mn-steels 2
of high strength 7
sticking 143
between billet and container 351
friction 145
stock material in wiredrawing 397
straight line particle movement in wiredrawing 429
strain
additive nature of true strain 59
conditions in rolling 369
definition of 58
deviatoric 66
effective value of 67
engineering shear strain 61
finding direction of principal strain 62
hydrostatic 66
increment 58
logarithmic 58
maximum shear strain 62
mean strain 66
natural 58
nominal 58
normal strain definition 61
plane strain state 60
principal value of 62
as process parameter 14
shear strain definition 61
transformation from true to nominal value 59
true strain 58
true strain in the neck 105
volume strain 63
strain and strain rate from velocity field 88
strain hardening 116
as parameter influencing necking 131
exponent 118
strain-induced softening 136
straining to improve mechanical properties 4
strain rate
conditions in rolling 370
constant value in plain strain compression 36
definition 67
effective value in frictionless compression 107
effective value of 67
as process parameter 14
as tensor 67
sensitivity 118
from velocity field 86
strength coefficient 118
stress
bi-axial 56
components 55
definition of 53
deviator 65
effective value of 67
finding principal stress 56
general state of 55
homogeneous 54
hydrostatic 65
mean (normal) stress 65
nominal 54
plane 56
positive or negative stress 55
states in technological tests 111
tensor 55
transformation 54
transformation by Mohr's circle 56
true 54
stress, strain, strain rate, compared by effective value 67
stretch forming 28
strip
drawing 149
material 442
rolling 376
rolling as cold working process 388
subsurface
lamination 321
layer of billet, flow of 328
subsurface sliding 143
surface appearance, speckled 149
surface expansion
in backward cup extrusion 297–299
in closed-die forging 316
surface layer of billet 24
surface quality
in extrusion 322
friction influence 139
importance of 13
surface ring pattern
in backward cup extrusion 299
in plain strain compression 36
technique 199–201
surface
appearance, boundary film lubrication 148
contamination of 144
created in metal forming 13
finish 13
quality 13
skin of billet, outflow of in extrusion 329–331
Swift's equation 119
T4-condition, formability of material 131
taper, used in extrusion 332
technological tests 92
description of test methods 93
mechanics of tests 92
in sheet-metal forming 437
temperature
conditions in extrusion 175
determined indirectly by microstructure 176
generation in metal forming 160
at hot spot inside extrusion die 173
in the die bearing in extrusion 172
measurement 164–167
as process parameter 14
sensitivity 118
at surface of Al-profile 176
tensile cracking, FEA study of tensile test 134
tensile strength 103
tensile stress cracking 134
FEA of for compression test 136
tensile stress zone
in normal wiredrawing 427
on outside of bend 439
behind roll gap in normal slab rolling 387
in strip rolling 392
tensile testing
to find flow curve 94
mechanics of test method 101
as technological test 93, 94
tensor
to describe strains 62
notation 55
theoretical methods in metal forming 204
thermal
effects 159–164
gradients in forging dies 167
response of thermocouple 165
thermal conditions in
Al-extrusion 171–176
light slab rolling pass 380
normal slab rolling pass 387
nonstationary forging 167–169
stationary processes 169–175
wire drawing 170–171
thermally coupled FEM models 226
thermocouple 159, 165
with short thermal response time 165
thermomechanical treatment 7
thick-film lubrication 146
thin film lubrication 148
thinning
in sheet metal forming 28
3D-DEPORM® 224
of wire behind drawing die 417, 418
torsion testing
deformation without shape change 96
to determine flow stress and ductility 96
as technological test 93, 96
transformation of microstructure in steel 118
transient, thermal 164
Tresca friction model 140
description of 142–144
mathematical expression 143
Tresca yield criterion 71
trimming
of flash 4, 21
by shearing 30
true strain from tensile test 102
true stress
best stress definition 54
from tensile test 101
tube drawing 396
using floating plug 396
using internal mandrel 396
tube extrusion 25
turns of wire over capstan 399
2D-DEFORM® 223
types of metal flow in Al extrusion 190
uniform
deformation in tensile test 102
energy method 204
unlubricated extrusion 321
upper bound method 213
in cylinder compression 216
friction sliding energy 214
homogeneous deformation energy 214
inhomogeneous deformation power 214
power consumed in velocity discontinuity 215
power consumption 213, 342
in wiredrawing 406
upsetting
optimization of process 331
of the extrusion billet 323
validation of
forging load in closed die forging 309
friction in plain strain compression 39
metal flow in plain strain compression 39
velocity
in backward cup extrusion 292
components 86
conditions in wiredrawing 399
discontinuities in wiredrawing 407
discontinuity in extrusion 341
discontinuity lines 214
field 84
field in normal wiredrawing 428
requirement to velocity field 87
velocity
of material particle through roll gap 365
visualization in FEA 225
Voce's equations 119
volume constancy 63
von Mises yield criterion 71
Wanheim and Bay's friction model 140
warm forming, temperature range of 118
weak
layers (z-direction lamination) 8
planes 8
wear of dies 13
influence of friction 139
web of extrusion die 333
welding chamber in extrusion 333
weld joint of thermocouple 165
wire breaks 26, 397
avoiding breaks in drawing 399, 404
wiredrawing 26–27, 395
bearing channel 26
as calibration process 27
capstan used in 26
as cold-forming process 397
as continuous process 26
converging die channel 26
experiments of Wistreich 414
force 404
force from Siebel's equation 410
as industrial process 397, 399
machines 397
parameters in industrial process 414
spooling of the wire 27
tension on the wire 410
Wistreich's experiments, drawing parameters used 414
workability 127, 269
of Al-alloys in extrusion 335
judged from tensile test 94
working
of metal 19
of microstructure 7
working conditions, unfavorable in rolling 383
workpiece 1
final stage 13
initial stage 12
wrinkling 19
in deep-drawing 444
in sheet-metal forming 441
wrought products 13
WUMSI simulator, working principle 98
X-ray inspection 130
yield criterion 70
graphical representation of 71
shear stress criterion 71
Tresca or von Mises 71
yield stress 103
Zener-Hollomon constitutive equation 122