The following is an example of how the nomogram is used.
A ladle contains 5000 kg of steel, from which we wish to pour a casting of total weight 1250 kg.
Thus we follow the arrows from the start point to junction A. From here a horizontal line connects to the next figure, where we select a pouring nozzle for the ladle of 60 mm diameter. At this junction B we drop a vertical line down to intersect with the line denoting that our ladle is about 1.5 m internal diameter. From this junction C we continue with a parallel line to the family of sloping lines, to find that our casting will pour in approximately 23 seconds.
Interestingly, the reader can check that the next 1250 kg casting in line (now starting with a ladle of 5000 – 1250ẳ3750 kg) will be found to pour in about 29 seconds, and the next in 34 seconds, and the next in 77 seconds, as the ladle progressively empties.
Appendix III 1101
Index
1.5 factor (initial/average fill rates), 1091–3
10 rules for good castings,seeRules 10 test bar mold, 500–2
A
Ablation casting (RS), 1019–23 Accuracy,seedimensional accuracy Acetylene black and fluidity, 132 Active feeding, 687–8
Additions to melts, 901 ADI,seeaustenitic ductile iron
‘Aero chocolate structure’ (zinc alloys), 987 Aerofoil fluidity tests for investment
casting, 138 Aerospace applications:
aluminium alloys, 612 castings and quenching, 712 location points, 729
AFS fitness number for aggregates, 918
Ag3Sn (intermetallic), 255 Aggregate molding materials:
AFS fitness number, 918 carbon, 922
chromite sand, 920 description, 939
hollow ceramic spheres, 922 minerals, 921–2
olivine, 919–21 silica sand, 919–20 zircon sand, 919–21 Aggregate molds:
coatings, 183–4 Cosworth Process, 1062 mold accuracy, 1038–1041 residual stress, 707
steels and dimensional accuracy, 1039
Aided flotation and detrainment, 897
Aided sedimentation and detrainment, 897–9 Air:
entrainment, 780, 941 gap and metal–mold interface,
191–8
melting and casting of nickel alloys, 383
quenching, 719
‘Air gap’ and rapid solidification, 1018–1023
‘Air inclusion’, term, 827 Air lock, 849
Alcan, 433, 906, 908
Alkaline phenolic (A-P) binders, 926, 934
Allan, Alec, 882 Alotech, 887, 897 Alumina:
bifilms, 89, 373–4, 894 bismuth, 88
furling and unfurling, 84–5 inclusions, 518
liquid aluminium, 21 liquid steel, 37
slag and flux inclusions, 32 stringers, 37–8
vertical filling of casts, 59 zinc alloys, 258 g-alumina, 271
Aluminides (titanium alloys), 227, 275, 387–90, 449 Aluminium:
aluminium inserts, 211 bifilms, 528, 535 bubble trails analysis, 73 contact pouring, 761–762 critical velocity, 48–9, 617 crucible melting, 881–2 diffusion coefficients, 12 ductility, 535
expansion and contraction, 1032 fcc structure, 543
feeders, 66, 660–1, 674–5 filtration, 899–900 fins, 213–14, 215–16 fluidity, 135 freezing range, 666
hexachlorethane degassing, 892 holding, 885
HPDC, 986
hydrogen, 6–7, 306–9, 895, 902 L-junctions, 213–14
magnesium alloys, 266 melting, 879
melts, 4 mold gases, 165 Ni-base alloys, 382–6 oxides, 28, 263–5, 904 reclamation and recyling of
aggregates, 932–5 residual stress (quenching), 712 rotary degassing, 893–6 rotary furnaces, 881 shot, 922
shot blasting, 1068 siphons, 888 solidification, 398 strength of castings, 617 strontium, 1051 structure, 3
surface tension, 756, 760 T-junctions, 213–14 thermal conductivity, 881 vapor zones in greensand mold,
159–60 wall plaques, 939 water vapor, 9 zinc alloys, 255–60 see alsoliquid aluminium Aluminium alloys:
7000 series, 378, 496, 713 7050 high strength, 559 ablation casting, 1019–23 accuracy, 1073
active feeding, 687–8 aerospace, 612 alumina films, 593 aluminium bronze
chills and fins, 217–19 critical velocity, 49–50 Durville casting, 948–55 feeder neck constriction,
674–5 feeding distance, 676–9 hydrogen solubility, 8 leaks, 1087
penetration barriers, 177 pouring, 54
surface films, 15
Al–0.2Cu porosity/interdendritic segregation, 240–1 Al–1Cu equiaxed grains, 485–6 Al–1Si–1Cu slip band direction, 547
1103
Aluminium alloys: (Continued) Al–1Sn hot tear, 470 Al–3Cu–5Si modulus, 131 Al–3Mg grain size, 543 Al–4Mg oxidation and corrosion
resistance, 578–9 Al–4.5Cu
ablation casting, 1019–20 CuAl2, 304
DAS, grain size and Tf, 236–7 elongation to fracture, 537–8 eutectic and time, 1071 furling and unfurling, 82–5 grain refinement, 542–5 inclusions, 517 macrosegregation, 705 quality indices, 594–7 tilt casting, 957
Al–4.5Cu–0.7Ag tear initiation, 475–6
Al–4.5Cu–1.5Mg ductility, 534, 536, 554–5 Al–4.5Mg bifilms, 91
Al–4.5–0.4Mg elongation v. yield strength, 538 Al–4.8Cu dendritic segregation,
249 Al–5Mg
deactivation of entrained films, 88
freezing range, 666 oxidation, 263–5
Al–5Si, penetration barriers, 177 Al–5Si–3Cu
chills, 207
residual stress, 574–5 Al–6Zn–2.7Mg–1.7Cu aging time,
538–9 Al–6.6Cu hot tear, 467–86 Al–7Si
cellular growth, 282, 287 chills, 207–8
magnesium, 655 modulus, 131 oxide bifilms, 227–8 phenolic-urethane binders, 654 superheat and fluidity, 132–3 thermal analysis, 305–6 Al–7Si–0.3Mg
channel defects, 253 external chills, 249 gas porosity, 443
gravity segregation, 711 macrosegregation, 706 viscosity, 128 Al–7Si–0.4Mg
ablation casting, 1019–23 bifilms, 98, 609–11 bubble trails, 73
deactivation of entrained films, 88–92
engineering, 270 flow channel behaviour,
220–3 fluidity, 110
furling and unfurling, 77–8 grain refinement, 542–5 heat treatment, 1072–73 HIPping, 1077–80 hot tear, 466
hydrogen porosity, 453–7 incipient melting, 1075 b-iron, 548–9
mechanical properties, 86–7 micro-blows, 654–5 microjetting, 66
pore initiation on bifilms, 433 pouring, 902–5
reduced pressure tests, 95–6 sand inclusions, 40–1 squeeze casting, 995 strontium, 273
surface films, 26–7, 32–5 uniform contraction, 1046–53 Al–7Si–0.4Mg-0.4Fe eutectic
phase, 553–4 Al–7Si–0.5Mg
fatigue/fracture, 560–1 shot blasting, 1068
uniform contraction, 1046–53 Al–7Si–0.6Mg fracture toughness,
557 Al–7Si–Mg
10 test bar mold, 500–2 elongation to fracture, 537–8 fatigue, 564–5
quality indices, 595 Al–8Si–3.3Cu–0.2Mg uniform
contraction, 1051 Al–9Si–4Mg oxide skin, 320–1 Al–10Mg
batch melting, 879–80 beryllium, 272 hipping, 1079
Al–10Si lost foam castings, 1004 Al–11Si
dendritic segregation, 247–50 surface films, 32, 34 Al–11.5Mg layer porosity, 441–2 Al–11.5Si bifilms evidence, 95 Al–12Si
feeder size, 400–1 freezing range, 666 oxide bifilms, 299–300 shrinkage porosity, 414, 416–17 Al–17Si
engine blocks, 136 uniform contraction, 1051,
1054
Al–21Cu channel segregation, 252 Al–Ag bonding, 210
Al–Cd hot tear, 470 Al–Cu
casting, 270
channel segregation, 252 continuous fluidity, 152–3 gravity segregation, 250–2 hot tearing, 465–6, 480–1, 483 hydrostatic tension, 409–10 silicon, 304
stress concentration, 473–4 susceptibility prediction of hot
tearing, 479–81, 483 Al–Cu–Fe/Mg alloying and hot
tears, 492
Al–Cu–Si fluidity and latent heat, 122–3, 136
Al–Li elastic modulus, 573 Al–Mg
barriers to diffusion, 461 beryllium, 93, 272 blister formation, 1073–4 casting, 270
eutectics and interdendritic feeding, 408–9 hot rolling, 1084–5
intergranular corrosion, 585–6 properties, 263–6
surface films, 13, 15 susceptibility prediction of hot
tearing, 479–83 Al–Mg2Si system, 303, 909 Al–Pb hot tear, 470 Al–Si
bifilms, 77–8, 227, 298, 332, 609–10
1104 Index
casting, 270 chills, 203
continuous fluidity, 151–3 CSC parameters, 482 eutectic Si, 279–98 extended fluidity, 148–9 feeding theory, 690 filter contamination, 851 flowability, 142 fluidity, 110–1
furling and unfurling, 77–88 gates, 815
Hall-Petch relation, 540 hot tear, 466
interdendritic phases, 548 iron-rich intermetallics, 299 latent heat and fluidity, 134–7 machining, 1081–2
magnesium, 272, 655 micrographs, 347 microjetting, 66 modulus, 131 mold explosions, 166–7 nucleation, 227–8, 284 phase diagram, 287–90 phosphorus, 283 sand blasting, 1067–9 shrinkage porosity initiation,
418–36
silicon particles, 228, 280–1, 284
in situ MMC, 908–9 sodium, 273
strontium, 260, 273, 302, 1051 susceptibility prediction of hot
tearing, 479–83 tensile properties, 501,
529–30 titanium, 277–8, 304
uniform contraction, 1047, 1050 Al–Si–0.4Mg reverbatory furnaces,
880–1
Al–Si–3.5Cu heat treatment, 1072 Al–Si–Mg ductility, 538 Al–Sn fluidity, 115–16 Al–Ti phase diagram, 275–6 Al–TiB2metal/matrix composite,
30 Al–Zn
AZ91, 262–3, 266, 267–9 fluidity, 116–18 superheat, 116–18
Al–Zn–Mg–Cu ductility, 538 surface, 1074 argon, 886
automatic greensand molding, 940 automotive systems, 520–1, 657 beryllium, 93
bifilms
Al–Si, 531, 538, 610 bismuth, 88 evidence, 94–100
furling and unfurling, 77–88 hydrogen precipitation, 79–80,
296
intermetallics in Al–Si alloys, 82 mechanism, 339
melting, 887 oxides, 82–5
pouring and turbulence, 271 shrinkage, 70, 80
binders, 923–32 bismuth, 88 borides, 518 boron, 918
bubble trails, 72, 75–6 bubbles, 70
carbides, 518
carbon black (thin-walled parts), 144 castings, 192–5, 269–71
‘cell count/size’, 240–1 ceramic foam filters, 839 chills, 203–4
‘Chinese script’, 303 clamping points, 736 confluence welds, 57–8, 63–4 contact pouring, 941 contraction, 887
corrosion, 518, 541, 575–87 counter-gravity casting, 1073–4 cracks, 46–7, 497
critical fall heights, 741 crucible melting, 881–2 cylinder heads, 955–6 datums, 729–30
deactivation of entrained films, 88–9 degassing, 888–96
delivery, 879–80
dendrite arm spacing, 86–7, 278–9 dendrites, 229, 231–2, 235 detrainment, 896, 901 dies, 912–13 direct chill, 378
dry hearth furnaces, 53, 612, 883–5 entrained inclusions, 273–4 expansion and contraction, 1032 external chills, 204–6
feeding, 663, 667 filtration, 899–901 fins, 1013 flow, 108–153 fluidized beds, 1075 furling and unfurling, 77–88 grain refinement, 182–3, 228,
274–8, 542–5 gravity die castings, 882 grit blasting, 1068–9, 1082 growth restriction parameter, 275–8 Hall-Petch relation, 540–1 heat pipes, 219
heat treatment, 719–20 high-volume, 762
hot isostatic pressing, 1077–80 HPDC, 913–14, 986–7, 1033, 1042,
1044
hydrogen, 5–9, 13–16, 306–9, 454, 457, 894
hydrostatic tensions, 396–9, 404–5, 412
inclusions, 3–5, 9, 273–4, 607 internal chills, 207–10 iron-rich metallics, 298–303 liquid, 271, 273, 880, 888 liquid fluxes, 38, 93 long-freezing-range (feeding
distance), 677 lost foam casting, 1001–5 lost-wax casting, 1051 magnetic molding, 917–18 markets, 270–1
melting, 879–910
melts, 879, 882, 886–98, 901–2, 909
metal/matrix composites, 29, 39 Mitsubishi, 256, 258
mushy state testing, 489
non-feeding role of feeders, 695–6 oxide bifilms, 892–7, 900, 909 oxides, 53, 64, 261, 271–2 painting, 1083
pouring, 54–7 quenching, 712
rapid solidification, 1018–9 residual stress, 707–14, 720–5 reverbatory furnaces, 880
Index 1105
Aluminium alloys: (Continued) rolling waves, 108 rotary degassing, 893–6 rubber molds, 931–2 salt cores, 914–15 sand castings, 61 sedimentation, 94 shrinkage porosity, 69 SiC MMC, 908 Sn addition, 1082 solid feeding, 412–18 steel
gauze filters, 852 titanium inserts, 210 strength, 719–22, 839 strontium, 272, 593, 1051 structure, 3
superplastic forming, 576–8 surface-tension-controlled filling,
751–6
surfaces, 19, 24, 25–7, 32–3, 32–5, 53, 56–7
temperature distribution in greensand mold, 159–60 thermal analysis, 305–6
Ti-Rich grain refiners, 612
‘tilt pouring’, 948, 954 titanium, 275, 543, 979 ultimate tensile strength, 553–5 ultra-clean, 612
ultrasonics, 4, 98, 541, 608 unzipping waves, 109 vacuum molding, 1005–8 yield strength, 539–48 zircon sand molds, 1068–9 Aluminium carbide in magnesium
alloys, 267 Aluminium nitride, 370, 894 Aluminium phosphide (AlP), 280–7,
290, 295, 298–9, 303 Aluminium silicate (mullite), 915 Ammonia and nitrogen porosity, 460–1 Anorthosite (aggregate molding
materials), 921 AOD (argon-oxygen-
decarburization), 889–91, 896 Area ratios in pressurized/
unpressurized filling, 861
‘Areal pore density’ (parameter), 433–4
Argon:
aluminium alloys, 886 degassing, 886 inert gas shroud, 902–3 magnesium alloys, 262–3 Asarco-type furnace, 884 ASTM radiographic standards, 518 Asymmetric films, 57
Austenite:
cast iron, 315–62 matrix structure, 224 pearlite transformation, 382 residual stress, 707 steels, 203, 379
Austenitic ductile iron (ADI), 359 Automatic bottom pouring (ABP),
882–3, 941–2 Automotive cylinder heads:
accuracy, 1062 air quenching, 719 Cosworth process, 974 die casting, 963–4 gravity dies, 942–3 residual stress, 707–14 strength reduction by heat
treatment, 720–2
‘Avoid bubble damage’ rule:
bubble damage
counter-gravity systems, 634–5
description, 658
gravity filling systems, 633–4 bubble trail, 631
‘Avoid convection damage’ rule:
academic background, 696–7 convection
countering, 704
damage and casting section thickness, 701–4 engineering imperatives, 697–701
‘Avoid core blows’ rule:
background, 635–47 core blow model study, 653 micro-blows, 654–5 outgassing pressure in cores,
647–53 prevention of blows, 655–9
‘Avoid laminar entrainment of the surface film’ rule:
hesitation and reversal, 629–30 horizontal stream flow, 627–8 meniscus, 623–5
oxide lap defects, 630
waterfall: oxide flow tube, 625–7
‘Avoid shrinkage damage’ rule:
definitions/background, 659–60 feeding to avoid shrinkage
problems, 660–1 seven feeding rules, 661–88
‘Avoid turbulent entrainment’
(critical velocity) rule:
introduction, 614–15
maximum velocity requirement, 615–19
‘no-fall’, 619–22
B
Back-diffusion and microsegregation, 245
Backing sands, 937–8 Base for sprue, 781–2 Batch melting (liquid metals),
879–83 Bcc,seebody-centered-cube Bells and loam, 929–30 Bernoulli, Daniel, 1095–7 Bernoulli equation, 1095–7 Berthelot’s experiment, 397 Beryllium:
aluminium alloys, 93 Al–Mg alloys, 272 iron-rich metallics, 298–303
‘Bifilm crack’, 26 Bifilms:
alumina, 368, 894 aluminium, 528, 535
aluminium alloys, 886, 899–900, 905, 907
blister formation, 1073–4 bubbles, 29–32, 72, 99, 892 buoyancy, 28
castings, 255 chills, 204
copper alloys, 314–15 corrosion, 581 Cosworth Process, 102 cracks, 910
creep, 576
DAS and tensile properties, 550–3 deactivation of entrained films,
88–92
defects in magnesium alloys, 261 density, 27–8
description, 24–8
1106 Index
detrainment, 94
directional solidification, 1014–6 double
entrainment defects, 24–42 evidence for bifilms, 94–100 furling and unfurling, 77–88 gray iron, 321
oxide flow tubes defects, 57, 65 surface flooding, 57
term, 21 ductile iron, 322–4 ductility, 533–9, 551 elastic modulus, 573–4
entrainment, 24–8, 51, 84, 86, 91, 98
flow regimes, 52
flux and slag inclusions, 32 furling and unfurling, 77–88 gold, 99–100
grain refinement, 274–5, 544 graphite, 339–43
gray iron, 320–322 Griffith’s cracks, 103
heat treatment of Al alloys, 727 HIPping, 1077
hot tearing, 493 hydrogen, 713–14 importance, 100–3
initiation of porosity, 418–26 iron, 904–5
leaks, 1086–8 magnesium alloys, 268 melts, 608–12, 655 microstructure, 542 Ni-base alloys, 386 nitride, 325–6, 352 non-destructive testing, 103 pitting corrosion, 582 pore initiation, 433–6 pronunciation, 24 reduced pressure test, 95–7 residual stress, 713
scanning electron microscopy, 95, 99
shrinkage, 80 silicon, 279
single crystal solidification, 1016–8 steels, 380, 562, 586, 904–5 tear growth, 476–9 titanium alloys, 389 ultrasonics, 4, 98, 608 viscosity, 128
waterfall effect, 625 white iron, 359 X-rays, 1086 zinc alloys, 258–60
see alsoaluminium alloys; double films;
oxide bifilms
Bimodal distribution, 506–7 Binary alloys, 230–1, 275–6 Binders:
alkaline phenolics, 926 cement, 930
chemical, 924–5
Croning shell process, 928–9 dry sand, 924
Effset process, 929 fluid (castable) sand, 930–1 furans, 925–6
gravity dies, 943 greensand, 923–4
hot box and warm box processes, 928
light-metal casting, 928 loam, 929–30 phenol-urethane, 926 silicates, 926–9, 937, 1040 sodium polyphosphate glass, 927 sodium silicate, 926–9, 937, 1040 Bismuth, 88, 232
Blind casters, 680–1 Blind feeders, 669, 680–2 Blister formation, 1073–4 Blow defect, 635, 637
Blow holes and gas porosity, 445 Blowterm, 636
Blow-holeterm, 635 Blowholeterm, 635 Blows,seecore blows
Body-centered-cube (bcc) structure, 224, 301, 497, 544 Boron, 183
Boron nitride and Mg–Zr alloys, 268 Bottom-gating:
filling system, 750–1, 757–8 gravity pouring of open molds, 940 molds, 619
Bottom-pour ladle, 767–9, 944, 1100–1 Box shaped castings, 749 Branched columnar zone, 238 Brasses, 309–12
Briefcase handles (zinc alloys), 259
Bronze:
bubble trails, 75 cannon, 654 description, 302 foundries, 178
‘Freedom Bell’, 627–8 grain refinement, 544–5
‘skeins of geese’, 74 wall plaques, 939 see alsoaluminium alloys:
aluminium bronze Bubble damage:
‘avoid bubble damage’ rule, 631–5 copper, 74–5
description, 72
entrapment of small bubbles, 69–70 inclusion control, 826–7
leaks, 1086 radiography, 70–1 runner, 791
shrinkage porosity, 69
surface turbulence in filling system, 636–8
see alsoRule 4 for good castings Bubble damageterm, 69, 72, 827 Bubble trails, 1085–6
aluminium alloys, 72
aluminium and X-ray video, 68, 73
‘avoid bubble damage’ rule, 631–2 bifilms, 99
cast iron, 639–40 castings in vacuum, 76–7 collapse, 68
copper, 74–5 core blows, 639–40 description, 67 iron, 68–9, 75 length, 76
low-pressure casting, 75 structure, 67
Bubble traps, 835, 843 Bubbles:
bifilms, 29–32, 892 collapse, 31 core blows, 636–9 degassing, 891–3
detachment, 636, 639, 643–4 entrainment, 616, 775 gray iron, 639, 641–2 large, 28–9
leaks, 589
outgassing of cores, 636–9
Index 1107
Bubbles: (Continued) shape, 32 small, 28, 69–70 trail, 28–9
Buoyancy forces and liquid metals, 1031–2
Burst feeding (shrinkage porosity), 409–12
Bypass designs (surge control), 819–20
C
‘Cake core’ (mold design), 1034–6 Calcium cyanamide and steels,
379–80
Calcium in magnesium alloys, 263 Calcium silicide, 334, 369 Capillary attraction, 753 Capillary repulsion, 753 Carbon:
aggregate molding, 922
black and casting thin-walled parts, 144
cast iron, 315–16 ferrous alloys, 922
metal surface reactions (pick up and loss), 179–81
steels, 362–3, 367, 484, 497
‘Carbon boil’, 362
Carbon dioxide in magnesium alloys, 262
Carbon equivalent(CE), 316 Carbon equivalent value(CEV), 316,
335
Carbon films (lustrous carbon), 170–1, 326–31 Carbon monoxide:
cast iron, 317 gas porosity, 447–8
pressure in steel castings, 451 Carbon tetrachloride and tensile
strength, 397 Carbon-based filters for steels, 852 Carburization in low-carbon steels,
180 Cast iron:
bubble trails, 68–9, 75–6, 639–40 carbon, 315–16
carbon monoxide, 317 carbonyl, 172 CaSi, 613 chills, 207
chunky graphite, 357–9 core blows, 640–2 decarburization, 180–1 dies, 943–4
dimensional accuracy, 1033 Ellingham diagram, 318–19 expansion and contraction, 1032 Fe–C and graphite films, 330–1 flake graphite iron and inoculation,
334–43 gases, 316–18 graphite flakes, 228 gravity dies, 942–4 holders, 886 machining, 1080–3 microstructures
eutectic growth graphite/
austenite, 345–7 flake graphite iron, 334–43 graphite, 333–4
introduction, 332–3 nucleation and austenite mix,
343–5 nitrogen, 317–18 nodularity, 922
pressure requirement (feeding), 685–7
pressurized systems, 857–60 sand mold penetration, 176 solidification, 190–1
spheroidal graphite iron, 347–52 structure hypothesis summary,
360–2 surface films
bifilms in ductile iron, 322–4 carbon films, 326–31 introduction, 318 nitride bifilms, 325–6 oxide bifilms in gray iron,
320–2 oxides, 318–20
plate fracture defect in ductile iron, 324–5
temperature, 60 white iron, 359–60 Cast material:
just-in-time slurry production, 906–7
liquid metal, 905
metal/matrix composites, 907–8 Mg alloy slurry production from
granules, 907
partially solid mixtures, 905–6 rheocasting, 906
strain induced melt activation, 907 thixocasting, 906
Cast pre-forms for forging, 996–7 Cast-on fins, 219
Cast-resin patterns, 1045 Casting:
centrifugal, 980–5 constraint, 1055–61 counter-gravity, 960–79 dimensions statistics, 1025–6 gravity, 939–46
horizontal transfer, 947–60 industry structure, 600–2 lost foam, 1001–5
lost wax/ceramic mold processes, 997–1001
manufacture, 600–2 pressure assisted, 985–97 vacuum melting and casting,
1009–11 vacuum molding, 1005–8 vacuum-assisted, 1008–9 Casting accuracy:
non-uniform contraction, 1053–61 process comparison, 1061–3 shrinkage, 1048
summary, 1063
uniform contraction, 1046–52 Casting alloys:
aluminium, 269–309 cast iron, 315–62 copper, 309–15 introduction, 255 magnesium, 260–9 nickel, 382–6 steels, 362–82 titanium, 386–90 zinc, 255–60 Casting rules,seerules Cavitation description, 684
‘Cavitation’ (superelastic forming), 576
‘Cell count’, 241
‘Cell size’, 241
‘Cell’ term, 241
Cellular front growth, 229–30, 282 Cement binders, 930
Cementite (carbide), 360
Central versus external systems (gates and filling), 814–15
1108 Index
Centrifugal casting, 979–85 Centrifugal pumps for liquid metals,
969–70 Centrifuge casting, 980
Ceramic block filters, 838–40, 851 Ceramic foam filters, 838–9, 841–2, 851 Ceramic molds accuracy, 1041–2 Ceramic molds and cores:
investment shell (lost-wax) molds, 915–17
investment two-part block molds, 916
magnetic molding, 917–18 plaster investment block molds,
916–17 properties, 915
CFD,seecomputational fluid dynamics CGI,seecompacted graphite iron Channel segregation in aluminium
alloys, 252 Chaplets, 210, 1032
“Chattanooga Choo Choo”, 334 Chemical binders, 924–5 Chills:
benefits, 203–4 bifilms, 204 chaplets, 210 copper, 206–7 external, 204–7 feeding, 692
fins comparison, 215–18 heat transfer, 202–3 internal, 209–11 iron, 207
relative diffusivities, 206 thermal conductivity, 219 thickness, 219
‘Chinese script’, 268, 303 Choke in pressurized/unpressurized
systems, 857–62 Chromite sand (molding aggregate),
919, 920–1, 937–8 Chunky graphite (CHG), 357–9 Chvorinov’s rule, 130, 200–2, 663,
671, 689
Clamping points for machining, 736 Close packed cubic symmetries (fcc,
bcc), 301 Cloth filters siting, 834–6 CO2process (cores), 1040 Coal pyrolysis, 169
Cobalt:
aluminate and grain refinement, 182 Co-base alloys, 382–4, 613
ceramic molds and cores, 915–17 vacuum casting, 1009 molds, 183
COD,seecrack opening displacement Cold cracking:
crack growth, 497 crack initiation, 496–7 nucleation, 496 Cold cracking, term, 495–7
‘Cold crucible’ technique, 979 Cold lap defects, 628 Columnar dendrites, 232
Columnar-to-equiaxed transition and solidification, 238 Compacted graphite iron (CGI),
355–7, 359
Computational fluid dynamics (CFD), 148–9
Computer simulation:
convection, 694 feeding, 694
filling systems, 853, 856 molds and cores, 658–9 solidification of castings, 663 Cone test for hot tearing, 487–8 Confluence welds:
aluminium alloys, 63–4 Cosworth Process, 60 ductile iron casts, 64 filling instability, 61 mechanism, 62 surface films, 62–3 Conical basin:
pouring, 757–72 sprue, 785–6
Connective loops and convection, 704 Constitutional undercooling, 230, 232 Contact pouring, 761–2, 941 Continuous fluidity, 152 Continuous melting, 883–5 Continuous-Fluidity Length, 111, 151 Contraction:
allowance, 392, 1050 dimensional accuracy, 1032 see alsouniform contraction Controlled solidification:
conventional-shaped castings, 1013–4
cooling fins, 1013
directional solidification, 1014–6 rapid solidification casting,
1018–23
single crystal solidification, 1016–8 Controlled tilt casting (Durville
method):
description, 947 summary, 954–5 Convection:
connective loops, 704 Cosworth Process, 802 countering, 704
damage and casting section thickness, 701–4 heat transfer, 219–20
see alsorule 7 for good castings Conventional-shaped castings
(controlled
solidification), 1013–4 Cooling of castings, 1013, 1059 Cope surface evaporation, 163–4 Copeterm, 939
Cope–drag arrangement, 1036, 1039 Copper:
Asarco-type furnace, 884 bubble damage, 74–5 chills, 206–7
diffusion coefficients, 12 ductility, 517, 533 hot rolling, 1085 Copper alloys:
Aluminium bronze modulus, 664 bifilms, 314–15
brass, 309, 311–12 chills, 203 Cu–10Al
critical velocity, 46–8, 618 hydrogen porosity, 453 Cu–10Sn porosity, 406 Cu–Ni carbon, 457 Cu–Zn vaporization, 16
ductility and grain refinement, 545 Ellingham diagram, 313
gas porosity, 457 gases, 310–15 grain refinement, 315 granulated charcoal, 313–14 gunmetal, 309–10 lead, 17, 310 melting, 313–14 ounce metal, 310
Index 1109
Copper alloys: (Continued) penetration barriers, 177 phosphorus, 313
Reduced Pressure Test, 314 steam reaction, 311 sub-surface pinholes, 314 surface films, 310 zinc, 312 see alsobronze Core blows:
bubble trails, 639 bubbles, 636–9 cast iron, 640–1 condensation, 646 gas porosity, 647 gray iron, 639, 641–2 metal chills, 646 molds, 641 prevention, 655–9 steel boxes, 647
see alsorule 5 for good casting Core blows and gas porosity, 522–3 Core-Package System(CPS), 959–60 Cores:
assembly, 1037
dimensional problems, 1036 making, 1040
running system, 1054 see alsomolds and cores Cosworth Process:
accuracy and aggregate molds, 1062
bifilms, 102
bubble damage in counter-gravity systems, 634 confluence welds, 60 convection, 698 critical velocity, 618 electro-magnetic pumps, 971 entrainment of bubbles, 634 grain size in aluminium alloys, 541 incipient melting, 1074–5 ingates, 802
leak elimination, 1085 leaks, 591
liquid aluminium alloys, 886 location points, 730–6 pouring (Al alloys), 904
roll-over after casting, 502, 958–60 tensile strength, 553
Cothias process (squeeze casting), 993
Counter-gravity casting:
10 test bar mold, 502 aluminium alloys, 1073–4 counter-pressure, 967 description, 960–4
direct vertical injection, 976–7 failure modes for low-pressure
casting, 979–80 feedback control for counter-
gravity casting, 978–9 filling system design, 741 gravity problems, 745 liquid metal pumps, 970–6 low-pressure casting, 964–70 medium pressure die-casting,
967–8
programmable control, 977–8 surface turbulence, 747 T-Mag process, 968–9 terms, 960–1 VRC/PRC, 967–968 Counter-gravity filling:
bubble damage, 634–5 filling defects, 628
Griffin Process, 905, 911–12, 922 lost foam castings, 1004 magnesium alloys, 986 Counter-pressure casting (CPC), 967 CPS,see Core-Package System Crack opening displacement (COD),
559
‘Cracking’ term, 495
Cracks and tears, 465–95, 495–9 Creep, 575–6, 577–8
Cristobalite and investment shell molds, 915 Critical fall heights:
aluminium alloys, 744 filling systems, 745 liquids, 46, 54–7 Critical velocities:
aluminium, 48–9 aluminium bronze, 49–50 copper alloys, 46 equations, 43–4 filling systems, 745
good casting, 614–18, 618–19 liquid aluminium, 45–6, 52 liquids, 46
metals, 616 summary, 618–19 Weber Number, 48–50
Croning, Johannes, 928 Croning shell process, 1040 Crucible melting (electric resistance/
gas heated), 881–2 Cryolite (flux), 35
CSC (cracking susceptibility coefficient) for hot tearing, 480–3 Cupola shaft furnace for iron, 883–4 Cylindrical systems and location
points, 734–5 C–Cr steels and microsegregation,
246–7
D
Darby, Abraham, 939 DAS,seedendrite arm spacing Datums and location points, 729–30 Deactivation of entrained films,
88–92
Decarburization of iron castings, 180–1
Defects:
alloys, 101 blow, 635, 637 castings
bifilms, 526–7, 527–9 gas porosity, 520–4
inclusion types and diagnosis, 516–20
introduction, 516–17 quantification, 3 shrinkage porosity, 525–6 tears, cracks and bifilms, 526–7 cold lap, 628
‘dents’, 654 dross, 638, 640
entrainment, 309, 929, 980 exfoliation, 636
melts, 607
oxide lap, 628, 630–1 pouring, 741–5 Degassing (melts):
aluminium alloys, 892–6 bubbles, 871–3
gaseous argon shield, 890 liquid argon shield, 889–890 passive, 889
vacuum degassing, 896 Dendrite arm spacing (DAS):
ablation casting, 1019–23 aluminium alloys, 86, 278–9
1110 Index
cast materials, 3, 88 chills, 203 defects, 516
directional solidification, 1010 grain size, 236–7, 240 growth, 234–7
homogenization and solution treatments, 1070–1 nucleation, 228
pore initiation on bifilms, 433–6 solidification structure, 187 yield strength
bifilms, 550–3 description, 539, 545–6 heat treatment, 550
interdendritic spaces, restricted growth, 548–50 residual Hall-Petch hardening,
546–7 zinc alloys, 259 Dendrites:
aluminium nitride, 370 columnar, 232 grains, 232, 235 graphite, 345
growth, 229–30, 232–4, 238 hot tears, 467
instability condition, 231 d-iron, 380, 382 microsegregation, 245–7 segregation, 247–9, 705–6 Dendrites, term, 229
Dendritic segregation, 247–9, 995
‘Dent’ defects, 654 Detrainment (cleaning):
aided flotation, 897 aided sedimentation, 897–8 description, 92–4 filters, 900–1 filtration, 94, 899–900
natural flotation and sedimentation, 896–7
packed beds, 900 practical aspects, 901 rotary degassing, 94 sedimentation, 94 Diamond films, 331 Die-casting:
contraction allowance, 1050 expansion and contraction, 1032 exterior shapes, 1030–1 interior shapes, 1031–2
low-pressure, 964–7
maximum velocity requirement, 615–19
medium pressure, 967 zinc alloys, 1045 Differentiation of solid (grain
multiplication), 236–41
‘Diffraction mottle’, 542
‘Diffuser’ term (runner), 793 Diffusion coefficients of elements,
10–12 Digital laser-reading systems
(metrology), 1065
‘Dilute air’ (vacuum), 76 Dimensional accuracy of castings:
accuracy, 1046–63 alloys, 1032–3 description, 1025–9
expansion and contraction, 1032 ISO, 1025, 1029
metrology, 1063–6 molds, 1033–8, 1038–45 net shape concept, 1029–33 non-uniform contraction, 1053–61 tolerances, 1028
tooling, 1045–6 Direct chill (DC):
aluminium alloys, 378, 593 casting, 93
grain refinement, 898 packed beds, 900 residual stress, 710 Direct gates, 771, 795–6 Direct pour casting, 942 Direct pour filters, 845, 850–1 Direct squeeze casting, 993–6 Direct vertical injection, 974–7 Direct-acting piston displacement
pump, 974–5 Directional solidification (DS),
1014–6 Distortion,seenon-uniform
contraction Distortion and residual stress, 722 Division of sprue, 780–1 Double bifilmsterm, 24 Down-runner,seesprue DPI,seedye penetrant inspection Dragterm, 939
Dross defects, 638, 640
‘Dross stringers’ in ductile iron, 322–4
Dross trap (slag trap), 820, 827–8 Dry coatings for molds and cores, 186 Dry hearth furnaces, 53–4, 612,
884–5
DS,seedirectional solidification Ductile iron:
brittleness, 352 casting, 320 confluence welds, 64 critical velocity, 46–8 distortion, 1056–8
‘dross stringers’, 322–4 ductility, 360 feeding, 670 fluidity, 134 gas porosity, 459 gravity casting, 939–46 gravity dies, 942–4 growth, 344 machining, 1080–1 melts, 613 oxidation, 579–80 plate fracture defect, 324–5 pouring, 54
pyrolysis, 168
reclamation and recyling of aggregates, 932–8 strength and filters, 839 stringers, 322–4 sulfur, 181 surface films, 15 vaporization, 17
see alsospheroidal graphite iron Ductility:
bifilms, 528, 535, 551 copper, 517, 533 failure, 533, 535 freezing of castings, 536 layer porosity, 554 pores and cracks, 537 Duplex stainless steels, 363 Duralcan, 908
Durville casting (controlled tilt), 948–55
Dye-penetrant inspection (DPI), 383, 386, 1087
E
Ease of removal (castings), 747 ECAP,seeequal channel angular
pressing Effset process (ice binder), 929
Index 1111