Invar 36 Alloy Data.pdf

ASTM B753 Alloy T36 is a 36% nickel-iron alloy with a rate of thermal expansion approximately one-tenth that of carbon steel at temperatures up to 400°F (204°C). The alloy is used for applications where dimensional changes due to temperature variation must be minimized or in conjunction with high expansion alloys in applications where a motion is desired when the temperature changes.

The alloy has a 4-level rating scale for corrosion resistance, with factors affecting corrosion resistance including temperature, concentration, pH, impurities, aeration, velocity, crevices, deposits, metallurgical condition, stress, surface finish, and dissimilar metal contact.

Physical properties of the alloy include:

Specific gravity: 8.05
Density: 0.2910 lb/in3
Mean specific heat: 0.1230 Btu/lb/°F
Mean coefficient of thermal expansion (CTE):
+ 200°F (93°C): 0.72 x 10-⁶ in/in/°F
+ 300°F (149°C): 1.17 x 10-⁶ in/in/°F
+ 500°F (260°C): 2.32 x 10-⁶ in/in/°F
+ 700°F (371°C): 4.22 x 10-⁶ in/in/°F
Thermal conductivity: 72.85 Btu-in/hr/ft2/°F
Elastic modulus:
+ Annealed bar and strip: 20.5 x 10^3 ksi
+ Cold rolled: 21.5 x 10^3 ksi
Electrical resistivity: 495.0 ohm-cir-mil/ft at 70°F (21°C)
Temperature coefficient of electrical resistance: 6.11 x 10-⁴ ohm/ohm/°F
Curie temperature: 535°F (279°C)
Melting range: 2600°F (1427°C)

The alloy has a low coefficient of thermal expansion, making it suitable for applications where dimensional changes due to temperature variation must be minimized. It is used in various markets, including aerospace, consumer, medical, defense, and industrial, and has applications in semiconductor components, electronic devices, optical and laser systems, and temperature regulator components.