Invar is a nickel-iron alloy notable for its uniquely low coefficient of thermal expansion, a name derived from the word invariable. Swiss physicist Charles Edouard Guillaume discovered the alloy in 1895, work for which he received the Nobel Prize in Physics in 1920 for his discovery of anomalies in nickel-steel alloys. Because it barely expands or contracts as temperature changes, it became the material of choice for precision instruments: watch balance wheels and pendulum rods, surveying leveling rods, seismic creep gauges, color-television shadow-mask frames, and the structural components that support the dimension-sensitive optics of astronomical telescopes. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/
Facts
Primary UsePrecision instruments and clocks, surveying leveling rods, and structural components of astronomical telescopes, wherever near-zero thermal expansion matters. 1 Classification
Material Class Connections
Associated With
Source Invar (Wikipedia)Wikipedia contributors
A low-expansion alloy engineered for dimensional stability in precision instruments.
Invar is roughly 64 percent iron and 36 percent nickel; its low-expansion behavior comes from the nickel content.
Source Invar (Wikipedia)Wikipedia contributors
In Field
Source Invar (Wikipedia)Wikipedia contributors
Sources
1. Invar (Wikipedia)
Wikipedia contributors, Wikimedia FoundationIntroduction
The discovery of the alloy was made in 1895 by Swiss physicist Charles Edouard Guillaume for which he received the Nobel Prize in Physics in 1920.
Applications
Invar is used where high dimensional stability is required, such as precision instruments, clocks, seismic creep gauges, color-television tubes' shadow-mask frames, valves in engines and large aerostructure molds.
material-class sentence
Invar is a nickel-iron alloy notable for its uniquely low coefficient of thermal expansion, a name derived from the word invariable.
- In Category: Material
- In Field: Materials Engineering
- Associated With: Nickel
Associated With: Cathode Ray Tube, Applications section
Invar is used where high dimensional stability is required, such as precision instruments, clocks, seismic creep gauges, color-television tubes' shadow-mask frames, valves in engines and large aerostructure molds.
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