Thermal expansion

In physics, thermal expansion is the tendency of matter to increase in volume or pressure when heated. For liquids and solids the amount of expansion will normally vary depending on the material's coefficient of thermal expansion. While for Gasses the change in volume or pressure is related to the container that the gas is in, this can be easily estimated by the ideal gas law.

Related Topics:
Physics - Volume - Pressure - Coefficient of thermal expansion - Ideal gas law

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To accurately calculate thermal expansion of a substance a more advanced Equation of state must be used. This equation would be able to calculate thermal expansion among with many other state functions.

Related Topics:
Equation of state - State function

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Most materials expand when heated and contract when cooled. The amount a material expands or contracts is estimated by the formula:

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(L_{final} - L_{initial}) / L_{initial} = lpha (T_{final} - T_{initial}) where lpha is the coefficient of thermal expansion in inverse kelvin.

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A number of materials have been discovered to exhibit negative thermal expansion, they contract on heating.

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In materials engineering, the three primary types of materials have well defined rates of expansion. Polymers expand as much as 10 times more than metals, which expand more than ceramics. Thermal expansion generally increases with bond energy. See PVT relation.

Related Topics:
Materials engineering - Polymer - Metal - Ceramic - PVT

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