29Ni53Fe17Co (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.
29Ni53Fe17Co has a nominal expansion coefficient of approximately 5 ppm/°C and inflection temperature of ~450 °C.
29Ni53Fe17Co is 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 is used for the flat pack and the dual-in-line package.
Chemical Composition
| Iron Fe Bal. | Nickel Ni 28.5-29.5% | Cobaltum Co 16.8-17.8% |
Mechanical Property
| Alloy State | Tensile Strength, N/mm² |
| Strip | 570.00 |
| Wire | 585.00 |
Physical Properties
| Density (g/cm3) |
Melting To (oC) |
| 8.17 | 1449.0 |
Coefficient of Expansion
| Alloy | Linear Coefficient of Thermal Expansion ā,10-6/℃ | |||||||
| 20-200℃ | 20-300℃ | 20-400℃ | 20-450℃ | 20-500℃ | 20-600℃ | 20-700℃ | 20-800℃ | |
| Kovar | 5.9 | 5.3 | 5.1 | 5.3 | 6.2 | 7.8 | 9.2 | 10.2 |
Applications
- Optoelectronics components
- Electronic tubes (power, X-ray, …)
- Medical devices
- Satellite components