General Description
Kovar is a nominal 29%Ni-17%Co-54%Fe alloy that is a well-known glass-sealing alloy suitable for sealing to hard glasses. Kovar has a nominal expansion coefficient of approximately 5 ppm/°C and inflection temperature of ~450 °C (840 °F).
Kovar (ASTM F15) 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 integrated circuits, it has been used for the flat pack and the dual-in-line package.
Chemical Composition
Grade | C% | P% | S% | Mn% | Si% | Cu% | Cr% | Mo% | Co% | Ni% | Fe% |
---|---|---|---|---|---|---|---|---|---|---|---|
Kovar Alloy | Max 0.03 | Max 0.02 | Max 0.02 | Max 0.50 | Max 0.30 | Max 0.20 | Max 0.20 | Max 0.20 | 16.8-17.8 | 28.5-29.5 | Bal. |
Designations
UNS K94610
Werkstoff Nr. 1.3981
Specifications
Strip/Sheet ASTM F15
Bar, Kovar thin wall tube is available per request
Physical Properties
Density: 8.17 g/cm3
Melting Point: 1449°C
Mechanical Properties
Form | Soft | 1/4 Hard | 1/2 Hard | 3/4 Hard | Full Hard |
---|---|---|---|---|---|
Kovar Strip | Max 570 | 520-630 | 590-900 | 600-770 | Min 700 |
Kovar Wire | Max 585 | 585-725 | 655-795 | 725-860 | Min 860 |
Linear Coefficient of Thermal Expansion ā,10-6/℃
Grade | 20-200℃ | 20-300℃ | 20-400℃ | 20-450℃ | 20-500℃ | 20-600℃ | 20-700℃ | 20-800℃ |
---|---|---|---|---|---|---|---|---|
Kovar Alloy | 5.9 | 5.3 | 5.1 | 5.3 | 6.2 | 7.8 | 9.2 | 10.2 |
Find out more about Kovar capillary tube on the our website.