Sintering of Si3N4 with liquid in the system Ce2O3---AIN---SiO2

Liquid phase sintering of Si₃N₄ with melts from the system Ce₂O₃---AIN---SiO₂ has been studied. The glass forming region in this system and the reaction products formed during sintering at 1750–1800°C were analysed. Sintering of Si₃N₄ with two melt compositions selected from outside the glass forming region yields fully dense Si₃N₄. Post sintering treatment at 1300°C resulted in devitrification with consequent improvement of high temperature mechanical properties. The mechanical properties of Si₃N₄ sintered with liquids in the system Ce₂O₃---AIN---SiO₂ were found to be inferior to those of liquids selected from Y₂O₃---AIN---SiO₂, but superior to those selected from the system MgO---AIN---SiO₂.