| abstract |
A process for heat-treating a composite material is disclosed. The composite material contains alumina, free silicon, and a beta-sialon material of the formula Si 6-z Al z O z N 8-z , wherein z is from 2.5 to 3.5. In the heat treatment process, the composite material is subjected to temperatures of 800-1,000 degrees centigrade, 1,240 to 1,260 degrees centigrade, and 1,400 to 1,450 degrees centigrade for various times and under specified conditions. |