Chemistry:Cerrosafe
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Short description: Fusible alloy with a low melting point
Cerrosafe is a fusible alloy with a low melting point. It is a non-eutectic mixture consisting of 42.5% bismuth, 37.7% lead, 11.3% tin, and 8.5% cadmium that melts between 158 °F (70 °C) and 190 °F (88 °C). It is useful for making reference castings whose dimensions can be correlated to those of the mold or other template due to its well-known thermal expansion properties during cooling. The alloy contracts during the first 30 minutes, allowing easy removal from a mold, then expands during the next 30 minutes to return to the exact original size. It then continues expanding at a known rate for 200 hours, allowing conversion of measurements of the casting back to those of the mold.[1][2]
Similar metals
| Alloy | Melting point | Eutectic? | Bismuth | Lead | Tin | Indium | Cadmium | Thallium|Thallium | Gallium | Antimony |
|---|---|---|---|---|---|---|---|---|---|---|
| Rose's metal | 98 °C (208 °F) | no | 50% | 25% | 25% | – | – | – | – | – |
| Cerrosafe | 74 °C (165 °F) | no | 42.5% | 37.7% | 11.3% | – | 8.5% | – | – | – |
| Wood's metal | 70 °C (158 °F) | yes | 50% | 26.7% | 13.3% | – | 10% | – | – | – |
| Field's metal | 62 °C (144 °F) | yes | 32.5% | – | 16.5% | 51% | – | – | – | – |
| Cerrolow 136 | 58 °C (136 °F) | yes | 49% | 18% | 12% | 21% | – | – | – | – |
| Cerrolow 117 | 47.2 °C (117 °F) | yes | 44.7% | 22.6% | 8.3% | 19.1% | 5.3% | – | – | – |
| Bi-Pb-Sn-Cd-In-Tl | 41.5 °C (107 °F) | yes | 40.3% | 22.2% | 10.7% | 17.7% | 8.1% | 1.1% | – | – |
| Galinstan | −19 °C (−2 °F) | yes | <1.5% | – | 9.5-10.5% | 21-22% | – | – | 68-69% | <1.5% |
References
- ↑ "Brownells Cerrosafe® Chamber Casting Alloy". http://www.brownells.com/gunsmith-tools-supplies/barrel-tools/barrel-chamfering-accessories/cerrosafe-reg-chamber-casting-alloy-prod384.aspx. Retrieved September 18, 2017.
- ↑ "CS Alloys Safe 165, Cerrosafe". http://www.csalloys.com/products-cerrosafe-alloy.html. Retrieved September 18, 2017.
External links
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