High Performance SiC-AlN Composites

High performance SiC-AlN composites were prepared by hot-pressing with α-SiC as starting powder. The effects of composition and sintering temperature on the properties of the materials were investigated, and SiC-5vol% AlN composites exhibited superior mechanical properties, with flexural strength, fracture toughness and Vickers hardness of 1130MPa, 6.2MPa-m1/2 and 28.6Gpa respectively. Microstructural observations revealed that the grain size of SiC-AlN composites was obviously inhibited and refined due to the formation of solid solutions and the development of subgrain boundaries in matrix SiC grain.