When you think of solders, you generally think of tin, lead, copper, silver. But have you ever considered bismuth?
Bismuth as a pure metal has a melting temperature of 271C but when bismuth is alloyed with other metals, it can bring the melting temperature of the resulting alloy down considerably. For example 58 Bismuth 42 Tin alloy is a eutectic alloy that melts at 138C. And there are a whole host of bismuth contained alloys that fall below the 100C range.
While this wide range of lower melting temperature alloys will not put them in the mainstream of electronics assembly, there are plenty of other applications including step soldering where they will be very useful. Stay tuned to this space for more ideas on using bismuth.
For more information, go to Bismuth.