Coefficient of Thermal Expansion

Physical Properties

Определение

The fractional change in length or volume of a material per degree change in temperature, expressed in µm/(m·K) or 10⁻⁶/°C. It describes how much a material expands or contracts with temperature.

Подробное объяснение

Steel expands at approximately 12 µm/(m·K), aluminum at 23 µm/(m·K), and Invar (a nickel-iron alloy) at only 1.2 µm/(m·K). Mismatches in thermal expansion between joined dissimilar metals can induce significant thermal stresses during temperature cycling. Invar and similar low-expansion alloys are used in precision instruments and bimetallic components to control dimensional changes.