Offer Kover -- 4J29

Glass sealed and controllled expansion alloys
*kovar alloy,ASTM F*5, Nilo-K,UNS K****0 (FeNi*9Co*7),Chinese 4J*9
*Specifications?ASTM F*5; DIN ****5; S.E.W. **5; Werkstoff Nr. 1.***1; AFNOR NF A*****1

Note:
A Nickel-Iron-Cobalt, controlled expansion alloy containing *9% Nickel. It?s coefficient of expansion (which decreases with rising temperature to the inflection point), matches the expansion rate of borosilicate glasses and aluminia ceramics. Applications include glass to metal seals in applications requiring high reliability or resistance to thermal shock, ie. high-power transmitting valves, transistor leads and heaters and photography flash bulbs.

Similar Grades:

Grade & Chemical Composition (see Table 1)
Table 1 Grade & Chemical Composition

Notes:

Mechanical Property (see Table *-Table 4)
Table 2 Tensile Strength of Wire

Physical Property (see Table 5 & Table 6)
Table 5 Coefficient of Linear Expansion

Note: The values in the table are for reference only.
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Usage: It is applied to hard glass-to-metal seals.

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.