Alloy K (Kovar®)

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Alloy K (Kovar®)

Alloy K (Kovar®*) is an iron-nickel-cobalt alloy whose chemical composition is controlled within narrow limits to ensure precise and uniform thermal expansion and mechanical characteristics. These properties make it an ideal alloy for use in high integrity glass-to-metal and ceramic-to-metal seals, particularly where the application requires resistance to thermal shock.

Alloy K (Kovar®*) is often used for the manufacture of hermetic seals with both the harder Pyrex or borosilicate glasses and alumina-type ceramic materials. The alloy finds extensive application in the production of transistors and diodes for lids and closures in a variety of hybrid electronic circuit packages and also in the manufacture of microwave tubes. In order to achieve optimum conditions for subsequent sealing operations, it is recommended to first condition the material using a thermal degassing / decarburising treatment carried out in a moist hydrogen atmosphere. This is then normally followed by a controlled oxidising heat treatment in order to create a tightly adherent surface oxide film of optimum nature and thickness.

Related Specifications of Alloy K (Kovar®*)

  • K94610
  • ASTM F15
  • 1.3981
  • FeNi29Co17

Nominal Composition of Alloy K (Kovar®*)

Fe 53%, Ni 29%, Co 17%

Mechanical Properties of Alloy K (Kovar®*)

Ultimate Tensile Strength (N/mm²) Proof Stress (N/mm²) Elongation (%) Hardness (HB)
540 380 30 160HV

Key Features of Alloy K (Kovar®*)

  • Uniform thermal expansion characteristics

Applications of Alloy K (Kovar®*)

General | Power and microwave tubes, transistors and diodes; lids and closures in a variety of hybrid electronic circuit packages

Columbia Metals – a leading supplier of Alloy K (Kovar®*)

With decades of experience and a huge range of stock, Columbia Metals is an industry leader in the supply of Alloy K (Kovar®*) and other high quality specialist engineering alloys.

To buy or learn more about Alloy K (Kovar®*) contact us now, or fill in the enquiry form on the right hand side and we will be in touch shortly.

  Related Specifications Mechanical Properties
Alloy Name BS UNS BS EN Others Ultimate Tensile Strength N/mm² Minimum Yield Strength N/mm² Elongation % Hardness HB  
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