4J29(Kovar),4J32,4J33,4J34,4J36(Invar),4J50 nickel alloy manufacturer

Product Overview

Description

4J29(Kovar),4J32,4J33,4J34,4J36(Invar),4J50 alloy products

 

 

Kovar is an iron-nickel-cobalt alloy with a coefficient of thermal expansion similar

 

 to that of hard (borosilicate) glass. This makes it especially suitable for uses which

 

require a matched-expansion seal between metal and glass parts. 

 

 

Thus kovar finds wide usage in the electronics industry for metal parts bonded to hard

 

glass envelopes for such devices as power tubes, x-ray tubes, etc, and other

 

applications requiring glass-to-metal seals. 

 

 

Specification:

 

	GB	ASTM	UNS	W.Nr
KOVAR	4J29	F15	K94610	1.3981

 

 

Chemical Composition:

 

Grade	%	Ni	Cr	Fe	Co	Cu	C	Mn	Si	P	S	Mo
Kovar	Min	28.5		Bal.	16.8
	Max	29.5	0.2		17.8	0.20	0.03	0.50	0.30	0.02	0.02	0.20

 

 

Mechanical Properties in the Annealed Condition:

 

Yield Strength (0.1% Offset)		Tensile Strength		Elongation
psi	MPa	psi	MPa	(%)
49,000	340	75,000	520	42

 

 

Coefficient of linear expansion: 

 

Grade	a/10-6·K-1
Kovar	200-300°C	20-400°C	20-450°C
	/	4.6-5.2	5.1-5.5