# Area Thermal Expansion Coefficient

on . Posted in Thermodynamics

Area thermal expansion coefficient, abbreviated as $$\alpha_a$$ (Greek symbol alpha), also called coefficient of aerial thermal expansion, is a measure of how a material expands or contracts in response to a change in temperature.  It describes the fractional change in size of a material per unit change in temperature.

This coefficient is important in materials science and engineering, especially in applications where temperature variations can affect the performance and structural integrity of materials, such as in construction, electronics, and aerospace.  Different materials have different thermal expansion properties, and engineers need to consider these factors in design and manufacturing processes to avoid issues related to thermal stress and dimensional changes.

### Area Thermal Expansion Coefficient FORMULA

$$\alpha_a = ( 1 \;/\; A ) \; ( \partial A \;/\; \partial T )$$
Symbol English Metric
$$\alpha_a$$   (Greek symbol alpha) = area thermal expansion coefficient $$in^2 \;/\; in^2\;F$$ $$mm^2 \;/\; mm^2\;C$$
$$A$$ = area of the object $$in^2$$ $$mm^2$$
$$\partial A$$ = infinitesimal area change $$in^2$$ $$mm^2$$
$$\partial T$$ = infinitesimal temperature change $$F$$ $$C$$
$$\frac{ \partial A }{ \partial T }$$ = rate of change of area with respect to temperature $$F$$ $$C$$