Precision Alloy Iron Nickel wire Invar/ Vacodil36/ Feni36 for Sealing Glass
Invar/ Vacodil36/ Feni36 Wire for Sealing Glass
Classification : low coefficient of thermal expansion alloy
Application: Invar is used where high dimensional stability is required, such as precision instruments, clocks, seismic creep gauges, television shadow-mask frames, valves in motors, and antimagnetic watches. In land surveying, when first-order (high-precision) elevation leveling is to be performed, the leveling rods used are made of Invar, instead of wood, fiberglass, or other metals. Invar struts were used in some pistons to limit their thermal expansion inside their cylinders.
Chemical Composition in %, Invar
| Ni 35-37% |
Fe . |
C 0.05% |
Si 0.3% |
Mn 0,3-0,6 % |
S o 0.015% |
| P 0.015% |
Mo 0.1% |
V 0.1% |
Al 0.1% |
Cu 0.1% |
Cr 0,15 % |
Basic physical constants and mechanical properties of the alloy:
Density: γ = 8,1 g / cm3;
Electric resistivity: ρ = 0,78 ohm mm2 ? / m;
The temperature of the Curie point: Θs = 230 ° C;
Modulus of elasticity E = 144 kN / mm2;
Linear expansion coefficient a1 (20-100 ºC) ≤1,5 * 10-6 ºC -1
| Temperature Range/ºC | 1/10-6ºC-1 | Temperature Range/ºC | 1/10-6ºC-1 |
| 20~-60 | 1.8 | 20~250 | 3.6 |
| 20~-40 | 1.8 | 20~300 | 5.2 |
| 20~-20 | 1.6 | 20~350 | 6.5 |
| 20~0 | 1.6 | 20~400 | 7.8 |
| 20~50 | 1.1 | 20~450 | 8.9 |
| 20~100 | 1.4 | 20~500 | 9.7 |
| 20~150 | 1.9 | 20~550 | 10.4 |
| 20~200 | 2.5 | 20~600 | 11 |
