Fusible Alloys

Fusible Alloys 

binary or multicomponent metal alloys with a melting point not higher than that of tin (about 232°C). They consist of various proportions of tin, bismuth, indium, lead, cadmium, zinc, antimony, gallium, and mercury (see Table 1). Certain fusible alloys melt within a range of temperatures rather than at a fixed temperature. Most fusible alloys shrink upon hardening, but those containing more than 55 percent bismuth expand.

Table 1. Properties of some fusible alloys
Chemical composition (percent)					Melting point (°C)
Bi	Pb	Sn	In	Others
—	—	12.5	20.5	67 Ga	10.6
44.7	22.6	8.3	19.1	5.3 Cd	46.8
50.0	26.7	13.3	—	10.0 Cd	70
52.5	32.0	15.5	—	—	95
58.0	—	42.0	—	—	138.5
—	—	91.0	—	9.0 Zn	199
48.0	28.5	14.5	—	9.0 Sb	103–227
67.0	16.0	17.0	—	—	96–149

Fusible alloys are used for solder, as fuses in electrical engineering and thermal devices, as dies and models in the preparation of complex metal and plastic casts, and as metallic putty and sealants.