The effect of z value on intergranular phase crystallization of αı/βı-SiAlON-TiN composites

Relationship between z value and intergranular phase (IGP) chemistry has not been completely developed to date for SiAlON based materials. In this study, the effect of z value of βı-SiAlON on crystallization and coalescence of IGP was investigated in αı/βı-SiAlON doped with Yb2O3-Sm2O3-CaO sintering additives and reinforced with TiN particles. αı/βı-SiAlON-TiN composites with compositions yielding different z values (0.3, 0.5, 0.7, 0.9 and 1.1) were prepared and sintered with gas pressure sintering route. Post sintering heat treatment was applied to sintered samples in order to enhance crystallization and coalescence of IGP. z value was proved an effective parameter on the intergranular phase chemistry and crystallization which are further influenced by post sintering heat treatment. No noticeable influence of heat treatment was observed on mechanical properties.