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.

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Alloy: An alloy is a combination, either in solution or compound, of two or more elements, which has a combination of at least two metals, and where the resultant material has metallic properties. An alloy with two components is called a binary alloy; one with three is a ternary alloy; one with four is a ...

Iron: Iron is a chemical element in the periodic table that has the symbol Fe (L.: Ferrum) and atomic number 26. Iron is a group 8 and period 4 metal. Iron is notable for being the final element produced by stellar nucleosynthesis, and thus the heaviest element which does not require a supernova or simil...

Nickel: :This article is about the element nickel. See also nickel (U.S. coin) and nickel (Canadian coin)....