Invar 36
Invar 36 is a 36% nickel-iron alloy with about one-tenth the coefficient of thermal expansion of carbon steel at temperatures up to 400°F (204°C).
This alloy has been used in applications where dimensional changes with temperature change must be minimized, such as in radio and electronic devices, aircraft control devices, and optical and laser systems.
Invar 36 alloys have also been used with high expansion alloys in applications that require motion when temperature changes, such as rod and tube assemblies for bimetal thermostats or thermostats.
Type Analysis
Applications
This alloy has been used in applications where dimensional changes with temperature change must be minimized, such as in radio and electronic devices, aircraft control devices, and optical and laser systems.
Invar 36 alloys have also been used with high expansion alloys in applications that require motion when temperature changes, such as rod and tube assemblies for bimetal thermostats or thermostats.
Physical Properties
Specific gravity ................8.05
density
lb/cin ............... 0.291
kg/cm ..............8055
thermal conductivity
Btu-in/ftθ/hr/°F ........72.6
W/mk K ....................10.5
electrical resistivity
ohm-cirm/ft ..............495
microhm-mm ................820
electrical temperature coefficient
resistivity
Per °F (70/212 °F) .............0.0006
Per °C (21/100 °C) ............... 0.0011
Heat Treatment
Proper heat treatment is very important to ensure that Invar 36 remains in a low internal stress state throughout the build and throughout the service life of the tool.
