Mechanical Properties of SiC-AIN Single-Phase Alloys and Two-Phase Composites

Abstract

In an attempt to strengthen and toughen silicon carbide ceramics, fully dense SiC-AlN alloys containing up to 25mol%AIN were fabricated by hot-isostatic pressing of the reaction-synthesized SiC-AlN solid solution powders. It was found that the solution of AlN yields much higher strength (up to 1000MPa at 5mol%AlN), and increases fracture toughness of SiC. In the SiC-AlN composites prepared by hot-isostatic pressing of the SiC and AlN elememtal powder mixtures, the addition of AlN particales improves fracture toughness more effectively in comparison with the single phase alloys.