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Low Melting Point
Bismuth Based Alloys |
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Properties of Fusible Alloys
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 | The chief component of Fusible Alloys is Bismuth, a heavy, coarse
crystalline metal that expands when it solidifies. Water and
Antimony also expand on freezing, but Bismuth expands much more than
the former, namely 3.3% of its volume. When Bismuth is alloyed with
other metals, such as Lead, Tin, and Cadmium, this expansion
is modified according to the relative percentages of Bismuth and
other components present. As a general rule, Bismuth alloys of
approximately 50 percent Bismuth exhibit little change of volume
during solidification. Alloys containing more than this tend to
expand during solidification and those containing less tend to
shrink during solidification. |
| After solidification, alloys containing both Bismuth and Lead in
optimum proportions grow in the solid state many hours afterwards.
Bismuth alloys that do not contain Lead expand during
solidification, with negligible shrinkage while cooling to room
temperature. |
| Most molten metals when solidified in moulds shrink
and pull away from moulds, failing to reproduce fine mould detail. Because Fusible
Alloys expand and push into mould detail when they solidify, they
are excellent for duplication and reproduction processes. This
characteristic of expansion and/or non-shrinkage, combined with low
melting temperature and ease of handling, are the major reasons for
their extensive use. A number of eutectic* and non-eutectic alloys
have been standardized.
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| * The word "EUTECTIC" describes an alloy, which, like pure
metals, has a single melting point. This melting point is usually lower
than that of any of the constituent metals. Thus pure Tin melts at 450
°F and pure Bismuth at 520 °F but combined in proportion 42% Tin and
58% Bismuth, they form a Eutectic which melts at 281 °F. |
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Eutectics |
Non-Eutectics |
| Properties |
Low |
Low |
Low |
Low |
Low |
Low |
Low |
|
117 |
136 |
158 |
255 |
281 |
158-190 |
281-338 |
| Melting
Temperature (oF) |
117 |
136 |
158 |
255 |
281 |
165 |
302 |
|
Range oF |
117-117 |
136 |
158-158 |
255-255 |
281-281 |
158-190 |
281-338 |
| Melting
Temperature (oC) |
47.2 |
57.8 |
70 |
124 |
138 |
72.5 |
150 |
|
Range oC |
47.2 - 47.2 |
57.8 -
57.8 |
70 - 70 |
124 - 124 |
138 - 138 |
70 - 88 |
138- 170 |
|
Tensile Strength Lbs/In2 |
5400 |
6300 |
5990 |
6400 |
8000 |
5400 |
8000 |
|
Tensile Strength Kg/mm2 |
3.8 |
4.4 |
4.2 |
4.5 |
5.6 |
3.8 |
5.6 |
| %Elongation in slow Loading |
1.5 |
50 |
200 |
60-70 |
200 |
220 |
200 |
| Brinell Hardness No. |
12 |
14 |
9.2 |
10.2 |
22 |
9 |
22 |
| *Specific Heat - Liquid/Solid |
.035 |
.032 |
.040 |
.035 |
.045 |
.040 |
.047 |
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*Latent Heat - Fusion Btu/Lb. |
6 |
8 |
14 |
7.2 |
20 |
10 |
22 |
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Conductivity (Electrical)
Compared with Pure Copper |
3.34% |
2.43% |
4.17% |
1.75% |
5.00% |
4.27% |
7.77% |
|
*Maximum Load -
30 Seconds Lbs/In2 |
- |
- |
10000 |
8000 |
15000 |
9000 |
15000 |
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*Maximum Load -
5 Minutes Lbs/In2 |
- |
- |
4000 |
4000 |
9000 |
3800 |
9500 |
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*Safe Load Sustained
-
Lbs/In2 |
- |
- |
300 |
300 |
500 |
300 |
50 |
| *Approximate |
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| |
Eutectics |
Non Eutectics |
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Growth/Shrinkage Time after Casting |
Low |
Low |
Low |
Low |
Low |
Low |
Low |
|
117 |
136 |
158 |
255 |
281 |
158-190 |
281-338 |
| 6 Minutes |
+.0002 |
+.0002 |
+.0027 |
-.0011 |
+.0007 |
-.0007 |
-.0001 |
| 30 Minutes |
.0000 |
+.0001 |
+.0045 |
-.0010 |
+.0006 |
-.0009 |
-.0001 |
| 1 Hour |
.0001 |
.0000 |
+.0051 |
-.0008 |
+.0006 |
.0000 |
-.0001 |
| 5 Hours |
-.0002 |
-.0002 |
+.0051 |
.0000 |
+.0005 |
+.0018 |
-.0001 |
| 1 Day |
-.0002 |
-.0002 |
+.0051 |
+.0008 |
+.0005 |
+.0022 |
-.0001 |
| 21 Days |
-.0002 |
-.0002 |
+.0057 |
+.0022 |
+.0005 |
+.0025 |
-.0001 |
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Cumulative Growth and Shrinkage, Inch per Inch Compared to
Cold Mold Dimensions. |
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Test Bar 2" x 2" x 10". |
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LOW 117 |
| Typical End Use |
Yield Temp: 117°F (47°C) |
Density: 0.320 lb/in3(8.86g/cm3) |
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Bismuth 44.7%
Lead 22.6%
Tin 8.3%
Cadmium 5.3% Indium 19.1% |
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Proof Casting (Internal dimensions) |
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Jigging or fixturing delicate parts for machining,
dental molds, prosthetic development work |
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Radiopaque contrast medium in X-ray |
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Fusible element in safety devices |
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Lens Blocking |
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Low temperature solder for Hobby applications |
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| INDUSTRY EQUIVALENTS: AIM 47,
AsarcoLo 117, CerroLOW117, Indalloy 117, Ostalloy 117 |
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LOW 136 |
| Typical End Use |
Yield Temp: 136°F (58°C) |
Density: 0.310 lb/in3(8.57g/cm3) |
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Bismuth 49%
Lead 16%
Tin 12%
Indium 21% |
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Anchor parts for machining (Jet blades) |
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Block lenses in optical manufacturing |
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Proof casting. testing and inspection |
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Fusible element in in fire sprinkler heads and other
safety devices |
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Fusible cores on compound cores |
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Sealing adjustment screws. |
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Low temperature solder for Hobby applications |
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| INDUSTRY EQUIVALENTS: AIM 58,
AsarcoLo 136, CerroLOW136, Indalloy 136, Ostalloy 136 |
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LOW 158 |
| Typical End Use |
Yield Temp: 158°F (70°C) |
Density: 0.339 lb/in3(9.38g/cm3) |
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Bismuth 50%
Lead 26.7%
Tin 13.3%
Cadmium 10% |
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Anchor bushings in drill jigs |
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Internal or external support of delicate
parts for machining |
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Cores for spinning |
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Fusible mandrels in filament winding. |
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Fiberglas lamination |
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Drop hammer and embossing dies |
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Tube bending filler (up to 1-3/4"
diameter) |
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Heat transfer medium in processing plastics,
chemicals, etc. (up to 255°F) |
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Shielding Blocks for Nuclear Medicine |
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| INDUSTRY EQUIVALENTS: AIM 70,
AsarcoLo 158, CerroBEND, Indalloy 158, Ostalloy 158 |
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LOW 158-190 |
| Typical End Use |
Yield Temp: 165°F (72.5°C) |
Density: 0.341 lb/in3(9.44g/cm3) |
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Bismuth 42.5%
Lead 37.7%
Tin 11.3%
Cadmium 8.5% |
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Toy soldier casting |
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Proof casting cavities (threads, dies, moulds,
blind holes) |
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Duplicate patterns in foundry match-plate making |
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Supporting work pieces while machining |
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Spray coating wood patterns |
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Masks for electroplating and spray-painting. |
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| INDUSTRY EQUIVALENTS: AIM
70/88, AsarcoLo 158-190, CerroSAFE |
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LOW 203 |
| Typical End Use |
Yield Temp: 203°F (95°C) |
Density: 0.350 lb/in3(9.85g/cm3) |
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Bismuth 52.5%
Lead 32%
Tin 15.5% |
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Cadmium Free alternative for LOW 158
for Nuclear Medicine. |
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| INDUSTRY EQUIVALENTS: AIM Bi46,
CerroSHIELD, Indalloy 42 |
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LOW 255 |
| Typical End Use |
Yield Temp:
255°F (124°C) |
Density: 0.380 lb/in3(10.27g/cm3) |
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Bismuth 55.5%
Lead 44.5% |
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Anchor cutlery handles, inserts in wood, metal
parts in glass (Tuflex doors)
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Make fusible spinning chucks |
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Mandrel for electroforms |
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Drop hammer dies, stretch form blocks |
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Moulds for plaster, plastics |
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Tube bending filler (over 1-3/4" diameter) |
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Hydrodynamic forming, seamless fittings |
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Duplicate patterns in pottery and foundry |
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Liquid metal in autoclaves, heat-treating |
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Heat transfer (Up to 327 °F) |
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Shielding Blocks for Nuclear Medicine |
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| INDUSTRY EQUIVALENTS: AIM 124,
AsarcoLo 255, CerroBASE, Indalloy 255, Ostalloy 255 |
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LOW 281 |
| Typical End Use |
Yield Temp: 281°F (138°C) |
Density: 0.315 lb/in3(8.72g/cm3) |
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Bismuth 58%
Tin 42% |
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Anchor shafts in permanent magnet rotors, locator
members in aircraft assembly fixtures, metal parts in glass, magnets
in fixtures |
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Make nests for parts in jigs and dial feed stations |
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Cores for electroforming |
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Embossing dies, form blocks |
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Joggle jaws |
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Lost wax pattern dies |
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Duplicate foundry patterns |
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Tracer models in profiling |
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Molds for plastics, sheet plastics, plastic teeth, prosthetic development |
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Potting electronic components |
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Laps for rifle barrels. |
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| INDUSTRY EQUIVALENTS: AIM 138,
AsarcoLo 281, CerroTRU, Indalloy 281, Ostalloy 281 |
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LOW 281-338 |
| Typical End Use |
Yield Temp:
302°F (150°C) |
Density: 0.296 lb/in3(8.20g/cm3) |
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Bismuth 40%
Tin 60% |
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Parallels LOW 281 in its end uses |
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Electroforming mandrels, lost wax pattern dies due
to greater dimensional accuracy |
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Holding jet turbine engine blades for machining. |
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| INDUSTRY EQUIVALENTS:
AIM 138/170, CerroCAST, Ostalloy 281338 |
© 2001-2011 Alchemy Castings (1464012
Ontario Inc.) & Alchemy Art Lead Products (1464013 Ontario
Inc.) |
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563 Kenilworth Ave. N.,
Hamilton, Ontario,
Canada L8H 4T8
Toll-Free: 1-866-312-9084,
Phone: (905) 312-9084,
Fax: (905) 312-9085,
Email
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