Silicon nitride ceramics with various alpha/beta phase ratio were fabricated by controlling sintering conditions of PECS process. Mechanical properties varied systematically with alpha/beta ratio. Young's modulus and hardness increased with alpha-Si3N4 Volume fraction, and fracture strength and toughness increased with beta-Si3N4 content.
Keywords: silicon nitride; alpha/beta phase ratio; mechanical property; microstructure; PECS; SPS