Kovar Alloy Round Bars Kovar Iron Nickel Cobalt Alloy

4j29 Alloy / Kovar Alloy Iron Nickel Cobalt Alloy

4J29 Kovar Alloy Round Bars is also known as Kovar alloy. The alloy has a linear expansion coefficient similar to that of silicon boron hard glass at 20-450°C, a higher Curie point, and good low-temperature structural stability.

Similar grades:

Kovar Alloy Round Bars Chemical composition:
C≤0.03%
Mn≤0.50%
Si≤0.30%
P≤0.020%
S≤0.020%
Cu≤0.20%
Cr≤0.20%
Mo≤0.20%
Ni=28.5~29.5%
Co=16.8~17.8%
Fe=rest

Kovar Alloy Round Bars Picture:

Under the condition that the average linear expansion coefficient reaches the standard, the content of nickel and cobalt is allowed to deviate from the range specified in Table 1-2. The content of aluminum, magnesium, zirconium and titanium should not exceed 0.10% each, and the total amount should not exceed 0.20%.

Heat treatment system
The performance test samples for the expansion coefficient and low temperature microstructure stability specified in the standard are heated to 900ºC±20ºC in a hydrogen atmosphere, kept for 1h, then heated to 1100ºC±20ºC, and kept for 15min, at a temperature of not more than 5ºC/min The speed is cooled to below 200 ºC.

Application overview
Kovar Alloy Round Bars is a typical Fe-Ni-Co hard glass sealing alloy commonly used in the world. It has been used for a long time in the aviation factory with stable performance. It is mainly used for glass sealing of electric vacuum components such as launch tubes, oscillator tubes, ignition tubes, magnetrons, transistors, sealed plugs, relays, integrated circuit lead wires, chassis, shells, brackets, etc. In the application, the selected glass should be matched with the expansion coefficient of the alloy. Strictly test its low temperature tissue stability according to the use temperature. Appropriate heat treatment should be carried out during processing to ensure that the material has good deep drawing properties. When using forgings, their air tightness should be strictly checked.