Descriptions of KOVARMolybdenum-Lanthanum-Wire

Kovar, also known as ASTM F 15 Alloy, is a controlled expansion alloy that is typically applied to high integrity glass and ceramic to metal seals, lids, lead frames and electronic package base.

Kovar is made of nickel, cobalt and iron. This alloy is designed to adapt to computer, microwave, hydrid, semiconductor and space age technology demands, thus, making this an essential resource to the defense, aerospace and telecommunications industries.

Chemical Composition

The chemical composition of KOVAR is outlined in the following table.

Element Content (%)
Nickel, Ni 29
Cobalt, Co 17
Silicon, Si 0.2
Chromium, Cr 0.2
Carbon, C 0.02
Iron, Fe Remainder


Physical Properties

The physical properties of super alloy KOVAR are tabulated below.

Properties Metric Imperial
Density 8.3 g/cm3 0.302 lb/in3
Melting point 1449°C 2640°F


Mechanical Properties

The following table shows mechanical properties of super alloy KOVAR.

Properties Metric Imperial
Tensile strength 518 MPa 75 ksi
Yield strength 276 MPA 40 ksi
Elongation 30% 30%
Hardness, (HRB) 80 80

KOVAR Available Forms:

Foil, sheet, rod, plate, wire, tube, extrusions, forgings

Applications of KOVAR

KOVAR’s expansion properties are useful in Pyrex glasses as well as alumina ceramics, thus making this super alloy one of the popular controlled expansion alloys that can be adapted for hermetic sealing applications.

Super alloy KOVAR is also applied in the following:

  • Glass sealing of metal components or lead wires, into hard glass or ceramic devices
  • In applications where low expansion with temperature change is an essential characteristic e.g. integrated circuits packaging
  • Scientific instruments
  • Microwave tubes
  • Hybrid packages
  • Power tubes
  • Transistors
  • Diodes

Packaging of KOVAR

Our KOVAR is carefully handled to minimize damage during storage and transportation and to preserve the quality of the product in its original condition.

Related Products of KOVAR


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