Thermal shock behavior of SiC whisker reinforced Si 3N 4/BN fibrous monolithic ceramics

Abstract

SiC whisker reinforced Si 3N 4/BN fibrous monolithic ceramics were fabricated by in situ synthesizing. The specimens were heated up to the test temperature and then quenched in a water bath of 25 °C. The thermal shock resistance parameters were calculated according to the elastic modulus, Poisson ratio, thermal expansion coefficient, strength and work of fracture. The thermal shock resistance critical temperature, Δ T, was 700 °C, which was improved more than SiC whisker reinforced Si 3N 4 ceramic. BN soft cell boundaries had an effect on the thermal shock behavior of the Si 3N 4/BN fibrous monolithic ceramics. The microstructures of the composites were observed by SEM.