STUDY ON HEAT-TREATMENT OF AIN/SiC_w COMPOSITES AND EFFECTS ON MICROSTRUCTURE AND PROPERTIES

摘要

AlN-SiC whisker composites with Y2O3 and SiO2 additives were heat-treated at 1300 C in air. The phase crmposition and microstructure were analyzed using XRD, SEM and HREM techniques to study the effect of heat-treatment on the microstructure and properties of the composites. The results reveal that the mechanical properties and high temperature oxidation resistance of the composite of which additives composition approaches the eutectic poi of Y2O3-SiO2 can be improved through the heat-treatment. Glass phase in the grain boundary is observed to react with the surface composition of AlN forming fibrous 2H8 Sialon, resulting a crossing structure produced by fibrous 2H8 Sialon and SiC whiskers.