Oxidation resistance of hot-pressed SiC–BN composites

The oxidation resistance of SiC–BN composites with different BN content hot-pressed from Si3N4, B4C and C was investigated. The oxidized products of SiC and BN were identified to be SiO2, C and B2O3, N2. SiO2 and B2O3 could further form a borosilicate glass which covered the surfaces of the samples and withstood oxidation because of its flowability and self-healing. The oxidation resistance of the SiC–BN composites in static air atmosphere deteriorated with the increase of temperature as well as of the BN content.