On the heat resistance of fused mullite

Heat resistance tests of experimental fused mullite materials and natural andalusite were carried out, and the change in the phase composition and microstructure of materials after heat treatment at 1400 °C. It was found that in the initial state, the fused materials have a slightly lower heat resistance than natural andalusite ― by 0.5‒1.0 %, but during service at high temperatures, the degeneration of the studied materials leads to the leveling of the initial difference in phase composition and structure, and the heat resistance of synthetic and natural materials become identical.