Field's metal
Field's metal, or Field's alloy is a fusible alloy that becomes liquid at approximately 62 °C (144 °F). It is named after its inventor, Simon Quellen Field.[1] It is a eutectic alloy of bismuth, indium, and tin, with the following percentages by weight: 32.5% Bi, 51% In, 16.5% Sn.
When prepared, Field's metal can be melted in hot water. Although it is much less dangerous to use than other commonly melted metals, such as lead or aluminum, contact with Field's metal, in the liquid state, will still cause 3rd degree burns extremely quickly.[2]
Field's metal is expensive, due to the price of indium, which makes up over half its mass. However, as it contains neither lead nor cadmium, it is a less toxic alternative to Wood's metal. It is used for die casting and rapid prototyping.
Similar alloys
| Alloy | Melting point | Eutectic? | Bismuth | Lead | Tin | Indium | Cadmium | 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% |