Definition of Invar in English:



  • [mass noun] An alloy of iron and nickel with a negligible coefficient of expansion, used in the making of clocks and scientific instruments.

    • ‘Choosing a material with a low coefficient of thermal expansion, such as Invar, is one method for minimizing thermal drift.’
    • ‘Aluminum is the most frequently used metal for structures, but in some cases stainless steels, titanium, or Invar may prove more advantageous.’
    • ‘This includes joining hard-to-weld and exotic materials such as the stainless steels, aluminum, magnesium, copper, beryllium copper, Hastelloy, Inconel, Invar and Kovar, especially in very thin cross sections.’
    • ‘Mr Bebb marvelled judges with a demonstration about Invar, an alloy which does not contract or expand when the temperature changes using nothing but balloons and chit-chat.’
    • ‘Typically, we stabilize the frame by some combination of environmental control and use of materials with significantly lower CTE (often several orders of magnitude smaller) than that of the sample, such as ULE, Zerodur, or Invar.’


Early 20th century: abbreviation of invariable.