Descriptions of goods:

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.

Chemical compositions(% in weight):

Nil:29, Co:17, Si:0.20(max.), Mn:0.50(max.), C:0.04(max.),Al:0.10(max.), Cr:0.10(max.), Zr:0.10(max.), Ti:0.10(max.), Mg:0.10(max.), Cu:0.20, Cr:0.20, Mo:0.20. Fe:balance