sealing kovar

Sealing alloy,Kovar and expansion alloys,Kovar alloy,ASTM F15, Nilo-K,UNS K94610 (FeNi29Co17),Chinese 4J29.

Note:

Sealing alloy Kovar and expansion alloys,Kovar alloy,ASTM F15, Nilo-K,UNS K94610 (FeNi29Co17),Chinese 4J29

 

A Nickel-Iron-Cobalt, controlled expansion alloy containing 29% Nickel. Its coefficient of expansion (which decreases with rising temperature to the inflection point), matches the expansion rate of borosilicate glasses and aluminia ceramics. Applications include glass to metal seals in applications requiring high reliability or resistance to thermal shock, ie. high-power transmitting valves, transistor leads and heaters and photography flash bulbs.

 

Alloy grades and chemical composition consistent with the provisions of table

the chemical composition of Kovar(%)
C	P	S	Mn	Si	Cu	Cr	Mo	Ni	Co	Fe
Not more than≤
0.03	0.020	0.020	0.5	0.30	0.20	0.20	0.20	28.5-29.5	16.8-17.8	Balance

 

Alloy typical expansion coefficient

Alloy Grades	The average linear expansion coefficient a,10-6/ oC
	20-200oC	20-300oC	20-400oC	20-450oC	20-500oC	20-600oC	20-700oC	20-800oC
kovar	5.9	5.3	5.1	5.3	6.2	7.8	9.2	10.2

 

Remark: The values in the table are for reference only.

 

Specification: Plate, sheet, strip, rod, bar, wire, tube.