SiC–AlN Particulate Composite

Abstract

A SiC–AlN composite was fabricated by mechanical mixing of SiC and AlN powders, hot pressed under 40MPa at 1950°C in Ar atmosphere. The object of this attempt was to achieve full density and a little solid solution formation. Fine microstructure and crack deflection behaviour are to improve the mechanical properties of the SiC–AlN composite. The bending strength and fracture toughness were achieved 800MPa and 7·6MPam1/2 at room temperature, respectively. The fracture toughness of the SiC–AlN composite shows minimal change between room temperature and 1400°C. Post-HIP improves the surface densification of the SiC–AlN composite resulting in an increase of the strength and the ability to resist oxidization. The bending strength of SiC–AlN composite increases from 800 to 1170MPa after HIP treatment for 1h under 187MPa at 1700°C in N2 atmosphere.