Kovar Alloy

Kovar Alloy
Introduction
Kovar alloy is a vacuum melted, iron-nickel-cobalt, low expansion alloy whose chemical composition is controlled within narrow limits to assure precise uniform thermal expansion properties. Extensive quality controls are employed in the manufacture of this alloy to ensure uniform physical and mechanical properties for ease in deep drawing, stamping and machining.

Typical Uses and Applications
Kovar alloy has been used for making hermetic seals with the harder Pyrex glasses and ceramic materials. This alloy has found wide application in power tubes, microwave tubes, transistors and diodes. In intergrated circuits, it has been used for the flat pack and the dual-in-line package.

Product details
Chemical composition:

Grade	C%	P%	S%	Mn%	Si%	Cu%	Cr%	Mo%	Ni%	Co%	Fe%
Kovar	Max 0.03	Max 0.020	Max 0.020	Max 0.50	Max 0.30	Max 0.20	Max 0.20	Max 0.20	28.5-29.5	16.8-17.8	Bal.

Specifications:

Grade	UNS	Werkstoff Nr.
Kovar	K94610	1.3981

Physical Properties:

Grade	Density	Melting Point
Kovar	8.17 g/cm3	1449°C

Mechanical Properties:

Grade	Tensile Strength N/mm²	Yield Strength N/mm²	Elongation
Kovar	517	345	30

Coefficient of Expansion

Alloy	Linear Coefficient of Thermal Expansion ,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

Available forms: 
Kovar wire, bar, rod, strip, forging, plate, sheet, tube, fastener and other standard forms are available.