Thermal Expansion Coefficient

Dimensional Change

Metals and polymers expand at different rates when exposed to the same thermal load. A high thermal expansion coefficient means that a part will grow substantially in length or volume when heated. Engineers calculate this change to ensure that moving parts do not seize during high-temperature cycles.

Thermal Match

Joining two materials with mismatched expansion rates creates high internal forces at the bond line. When the thermal expansion coefficient varies widely between the adhesive and the substrate, the joint can delaminate during rapid temperature swings. Designing assemblies with matched or similar coefficients prevents these joint failures and extends the life of the product.

Engineering Solution

Aerospace structures use composite materials that have an extremely low expansion rate to maintain their shape in flight. In electronics, the thermal expansion coefficient of the printed circuit board must match that of the silicon chips to prevent solder joints from cracking. Specifying materials with low expansion rates is the primary way to design stable high-precision systems.

This selection ensures that sensitive components can withstand the extreme temperature variations of orbital or high-altitude environments.