Electrical Optical Physical Thermal Chemical The Kyocera Museum of Fine Ceramics KYOCERA Corporation   HOME > Characteristics of Fine Ceramics > Thermal - Thermal Expansion  Low Thermal Expansion When materials are heated, their size and volume increase in small increments, in a phenomenon known as thermal expansion. Expansion values vary depending on the material being heated. The coefficient ratio of thermal expansion indicates how much a material expands per 1oC (2.2oF) rise in temperature. Fine Ceramics have low coefficients of thermal expansion — less than half those of stainless steels. Applications: Parts for high-precision measuring equipment. Coefficient of Thermal Expansion The ratio that a material expands in accordance with changes in temperature is called the coefficient of thermal expansion. Because Fine Ceramics possess low coefficients of thermal expansion, their distortion values, with respect to changes in temperature, are low. The coefficients of thermal expansion depend on the bond strength between the atoms that make up the materials. Covalent materials such as diamond, silicon carbide and silicon nitride have strong bonds between atoms, resulting in low coeficients of thermal expansion. In contrast, materials such as stainless steel possess weaker bonds between atoms, resulting in much higher coefficients of thermal expansion in comparison with Fine Ceramics. Coefficients of Thermal Expansion   For more information, please see Excerpt of Graph Values.