Crystallization of grain boundary phases in hot-pressed silicon nitride materials

Multicomponent oxide additions were used to replace magnesia as the densification aid for hot-pressing silicon nitride and silicon nitride-alumina materials. Crystallization of the silicate glass phases present after hot-pressing was encouraged by the use of an in situ heat treatment process. The phase constitutions of the materials produced by this method were determined using X-ray powder analysis. The kinetics of the densification of the silicon nitride materials were investigated, and these materials were examined using an X-ray diffractometer to study the textures produced by hot-pressing.