SiC-TiB2 Composite Densified by Pressureless Liquid-Phase Sintering

Particle reinforced SiC composites with the addition of TiB2 were fabricated in range of 1750°C to 1950°C by pressureless sintering by utilizing liquid phase with AlN-Y2O3 as sintering additives. The effective of sintering aids in densification, the mechanical properties of sintered sample and the microstructure had been investigated in this paper. The results showed that the best densification behaviors occurred in AlN:Y2O3 at 60 :40%mol ratio not at eutectic point. Adding TiB2 to SiC matrix increase the toughness and decreased the hardness. Microstructure analysis showed that the increasing of toughness was due to the crack deflection with some contribution intergranular fracture mechanism.