Kovar is a controlled expansion alloy. It is a nickel iron alloy with 29% nickel, 17% cobalt and the remaining balance is iron. The expansion characteristics of Kovar match both borosilicate (or Pyrex) glasses and alumina ceramics, making it one of the most popular of the controlled expansion alloys for hermetic sealing applications. Kovar is produced to ensure good properties for machining and deep drawing, and is a porosity free product.
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8.36 g/cm³ at 20 °C
Available widths: 1.6mm, 2.4mm, 3.2mm, 4.0mm, 4.8mm, 6.4mm, 8.0mm, 9.5mm, 12.7mm, 15.9mm, 19.1mm, 22.2mm, 25.4mm, 28.6mm, 31.8mm, 34.9mm, 38.1mm, 41.3mm, 44.5mm, 47.6mm, 50.8mm, 57.2mm, 63.8mm, 77.5mm, 88.9mm, 152.4mm
1.6 - 152.4 mm
Coefficient of thermal expansionα
5.8E-6 1/K at 100 °C
from 30°C to the mentioned temperature
Specific heat capacitycp
460 J/(kg·K) at 20 °C
17 W/(m·K) at 20 °C
4E-7 Ω·m at 20 °C
Common applications of Kovar: Glass-to-metal hermetic sealing with hard borosilicate glass, ceramic-to-metal sealing, power tubes, microwave tubes, transistors, diodes, integrated circuits, hybrid packages
This material data has been provided by Matmatch.