Invar

Invar is an alloy of iron (64%) and nickel (36%) with some carbon and chromium. Sometimes small amounts of selenium are added to improve machinability. Due to its small coefficient of thermal expansion (about 10-6 K-1 in length; some formulations have negative CoE) it is used in precision instruments (clocks, physics laboratory devices, seismic creep gauges, shadow-mask frames,http://www.nickelinstitute.org/index.cfm/ci_id/12313.htm valves in motors, etc.) However, it has a propensity to creep.

Related Topics:
Alloy - Iron - Nickel - Carbon - Chromium - Selenium - Coefficient of thermal expansion - K - Clock - Shadow-mask - Creep

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