Prasad S. Khadkikar

The principles and properties of thermostat metals

Although thermostat metals, or bimetals, have been in existence for more than 200 years, they remain relatively unknown outside a few specific industries. The unique property of flexivity that characterizes thermostat metals allows these materials not only to sense the temperature but also to control it by making or breaking an electrical circuit. Although the design of a thermostat metal primarily depends upon the expansion characteristics of the component metals, resistivity is also critical in some applications. In addition, the strength and fatigue properties, interface integrity, and residual stresses play a major role in determining the behavior of thermostat-metal elements.