What is the coefficient of thermal expansion?

The coefficient of thermal expansion is defined as a measure of how much a material expands when subjected to a change in temperature. This property is crucial in engineering and materials science because it helps predict how different materials will behave under temperature variations.

As the temperature of a material increases, its particles gain kinetic energy and tend to move apart, leading to an increase in size. The coefficient quantifies this relationship by indicating the rate at which the linear dimensions (or sometimes volume) of a material change with temperature. Specifically, it is expressed as a change in length (or volume) per unit length (or volume) per degree of temperature change, allowing engineers to calculate how much expansion or contraction to expect in applications such as structural engineering, mechanical assembly, and thermal management.

The other choices relate to different material properties but do not directly describe thermal expansion. For example, strength pertains to the ability of a material to resist forces, while thermal conductivity relates to how well a material conducts heat. Understanding the coefficient of thermal expansion is essential for ensuring that structures and devices perform as intended across varying temperatures.