fusible alloys

The terms fusible metals, or fusible alloys, describe a group of alloys that have melting points below that of tin (232 C, 449 F). Most of these substances are mixtures of metals that by themselves have low melting points, such as tin, bismuth, and lead. Fusible alloys are employed as solder, in safety sprinklers that automatically spray out water when the heat of a fire melts the alloy, and in fuses for breaking an electrical circuit when the current becomes excessive. Simple solders composed of lead and tin include plumber's solder and electrician's solder. Many fusible alloys are formulated to melt at 90100 C (194212 F). Darcet's alloy (50 parts bismuth, 25 tin, 25 lead) melts at 98 C. The alloy Wood's metal, in which half the tin in Darcet's alloy is replaced with cadmium, melts at 70 C.