SiAION Ceramics

The phase relations in and physical properties of SiAlON ceramics prepared by the hot isostatic pressing technique or by pressureless sintering with a sintering aid are reviewed. The sintering aid used is an AIN and Al 2 O 3 mixture either pure or in combination with Y 2 O 3 and/or various rare‐earth oxides. Special attention is paid to the amount and type of phase(s) formed and to how properties such as hardness (HV10), fracture toughness ( K IC ), and oxidation resistance vary with the sintering aid used for different types of SiAlON materials, i.e., O'‐, almost monophasic α‐, pure β‐, and mixed (α+β)‐SiAION Ceramics.