Expansion alloy ( Widely known as Kovar or Invar alloy) having a specific coefficient of thermal expansion, also it has good sealing properties, weldability, corrosion resistance, workability and ease of machinability, and within the temperature range is not allowed to cause expansion characteristics significant changes in the phase transition.
Expansion alloys in the manufacturing process must be accurate control of chemical composition of the alloy, and its products can include rod, sheet, strip, wire and tube.
OHMALLOY can provide the expansion alloy in wire form and the following grade:
1. Chemical composition(%)
|
Grade
|
C
|
Si
|
Mn
|
P
|
S
|
Ni
|
Co
|
Fe
|
|
4J29
|
0.015
|
0.12
|
0.25
|
0.006
|
0.005
|
29.10
|
17.3
|
Bal
|
|
4J33
|
0.03
|
0.12
|
0.26
|
0.006
|
0.005
|
33.1
|
14.5
|
Bal
|
|
4J42
|
0.03
|
0.12
|
0.50
|
0.006
|
0.005
|
41.7
|
0.05
|
Bal
|
|
4J50
|
0.03
|
0.12
|
0.50
|
0.006
|
0.005
|
50
|
1.0
|
Bal
|
2. Physical properties
|
Grade
|
Density(g/cm3)
|
Thermal expansion coefficient (10-6/℃)
|
Curie point(℃)
|
Volume resistivity(μΩ.cm)
|
Thermal conductivity(W/m. ℃)
|
|
4J29
|
8.17
|
5.0(20~300℃)
5.2(20~450℃
|
430
|
46(20℃)
|
20.3
|
|
4J33
|
8.16
|
6.4(20~400℃)
6.9(20~500℃
|
440
|
44(20℃)
|
18.6
|
|
4J42
|
8.14
|
4.8(20~300℃)
6.9(20~450℃)
|
350
|
62(20℃)
|
15.5
|
|
4J50
|
8.21
|
9.4(20~400℃)
9.7(20~500℃)
|
500
|
44(20℃)
|
16.7
|
OHMALLOY can make the wire from dia 0.05mm to 8mm. The rod dia from 8mm to 200mm.
