ASTM TM1 Bimetal Strip 5j1480 Tb 140/80 Thermal Bimetal Strip

5j1480 Thermal bimetal strip Ni22Cr3/Ni36 TB140/80 ASTM TM1

A bimetal or thermostatic metal is a sheet or strip of two or more composite materials having different coefficients of linear thermal expansion bonded by riveting, brazing or welding. The material with the larger coefficient of thermal expansion (CTE) is considered as the active component, and that of smaller CTE is the passive component. The active component usually has alloys containing iron, manganese, nickel, or chrome in varying amounts. Whereas on the passive side, invar is often chosen, an iron-nickel alloy containing 36% nickel. Some bimetals include a third layer of copper or nickel in between the active and passive sides in order to increase thermal conductivity and decrease the material's electrical resistivity.

Bimetals work with the propensity of metals to expand when heated, and contract when cooled. The resulting change of curvature, or bending, in response to temperature change, is a fundamental property of all thermostatic bimetals. In effect, the temperature change is converted into mechanical displacement. The behaviour of bimetals is predictable and repeatable. The components used for bimetals are selected for their temperature characteristics as well as their thermal conductivity, stability, strength, workability, and electrical properties.

 
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