Microstructure of Si3N4-TiN Ceramics Prepared from Si, TiC and TiO2 Mixed Powder

Si3N4-TiN ceramics prepared from Si, TiC and TiO2 mixed powder compacts were investigated. Si3N4 matrix and TiN particles were formed during the sintering process of the ceramics. TiN particles about 100nm in diameter were dispersed within β-Si3N4 matrix particles. Yttrium which originated from the sintering aid (Y2O3) was detected at Si3N4 matrix/TiN particle boundary, when the TiN particles were intragranularly located. It is suggested that the TiN particles were incorporated in the Si3N4 during the α→β transformation or grain growth of the Si3N4 grains.