Complaint
OhmAlloy-4J50(Expansion alloy)
(Common Name:50H, N50, Vacovit 500, FeNi50)
4J50 alloy is mainly composed of iron, nickel elements. It is characterized with a fixed coefficient of expansion. Increase the thermal expansion coefficient and the Curie point with increase of nickel content.
4J50 alloy is widely used the structure of the sealing material in the electric vacuum industry.
Normal composition%
Ni | 49.5~50.5 | Fe | Bal. | Co | 1.0 | Si | ≤0.3 |
Mo | - | Cu | - | Cr | - | Mn | ≤0.8 |
C | ≤0.05 | P | ≤0.02 | S | ≤0.02 | Al | ≤0.1 |
Typical Physical properties
Density (g/cm3) | 8.21 |
Electrical resistivity at 20ºC(Ωmm2/m) | 0.44 |
Thermal conductivity, λ/ W/(m*ºC) | 16.7 |
Curie pointTc/ ºC | 500 |
Elastic Modulus, E/ Gpa | 158 |
Coefficient of expansion
θ/ºC | α1/10-6ºC-1 | θ/ºC | α1/10-6ºC-1 |
20~100 | 9.8 | 20~400 | 9.4 |
20~200 | 9.8 | 20~450 | 9.4 |
20~300 | 9.5 | 20~500 | 9.7 |
20~350 | 9.4 | 20~600 | 10.6 |
| Tensile Strength | Elongation |
| Mpa | % |
| 490 | 35 |
| Annealing | Heated to900 ±20ºCin a hydrogen atmosphere |
| Holding time, h | 1 hour |
| cooling | With speed not more than 5 ºC / min. cooling to below 200 ºC |
| Alloys Name | Type | Dimension | |
| OhmAlloy-4J50 | Wire | D=0.1~8mm | |
| OhmAlloy-4J50 | Strip | W= 5~250mm | T= 0.1mm |
| OhmAlloy-4J50 | Foil | W= 10~100mm | T= 0.01~0.1 |
| OhmAlloy-4J50 | Bar | Dia=8~100mm | L=50~1000 |
