Development of Low–Thermal Expansion Mullite Bodies

A series of ceramic compositions based on variations in the crystal–glass ratio of a mullite body were developed. The thermal expansion of these compositions varies from 3.7 to 5.0×10 –6 /°C to 800°C. The materials are particularly useful for applications involving silicon, in that an identical thermal expansion is available. The high–temperature creep data for the lower–expansion compositions are inferior as a result of their higher glass contents. Raw material sources and fabrication procedures for specific compositions are given.