High Temperature Properties of mixed alpha/beta-SIALON Materials

The mechanical behavior of mixed alpha/beta-SIAlON materials was studied at elevated temperatures. The high temperature properties of the materials studied was strongly influenced by the chemical composition (alpha-content and grain boundary phase) of the SIAlON's. A high content of alpha-SIAlON was beneficial in terms of creep behavior of the materials. The same materials, however were characterized by a considerably degradated fracture behavior at elevated temperatures in air because of a crack growth process enhanced by the poor oxidation resistance of these materials.