Kovar Alloy 4J29
Nilo / Alloy K W.Nr.: 1.3981
UNS: K94610 ASTM F15
Fixed-expansion glass-encapsulated iron-nickel-cobalt alloys, Kovar alloys, have a linear thermal expansion coefficient similar to that of hard glass within a certain temperature range
For mating sealing with hard glass
Nilo / Alloy K W.Nr.: 1.3981
UNS: K94610
Kovar alloy is a vacuum melted, iron-nickel-cobalt, low expansion alloy which has been used for making hermetic seals with the harder Pyrex glasses and ceramic materials. The coefficient of thermal expansion (CTE) is the most significant property of Kovar. It is carefully formulated to produce a low CTE below the Curie point (435°C or 815ºF) which is remarkably similar to hard / borosilicate glass or ceramic.
4J29 (KOVAR) alloy has a linear expansion coefficient similar to that of borosilicate hard glass at 20-450 ° C, a higher Curie point, and good low-temperature structural stability. The oxide film of the alloy is dense and can be well wetted by glass. And it does not interact with mercury, so it is suitable for use in instruments containing mercury discharge. It is the main sealing structure material of electric vacuum devices.
Kovar K94610 Chemical Analysis
C | .03 max |
MN | 2.0 max |
P | .04 max |
S | .03 max |
Si | 1.0 max |
Cr | 20.0- 22.0 |
Mo | 6.0- 7.0 |
Ni | 23.5- 25.5 |
Cu | .75 max |
N | .18- .25 |
Fe | bal |
Kovar tube size:
OD:0.2-6mm
WT: 0.02-2mm
Kovar Applications: Hermetic sealing
Electronics Industry, like lightbulb ends and microwave tubes, to x-ray tubes and hybrid or integrated electronic circuit packages.
Aerospace Industry also uses Kovar for its hermetic sealing properties, Kovar is the perfect choice
Other applications and uses include:
Transistors and diodes
Scientific vacuum systems and instruments
Concentrated solar power