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.
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