Sensitivity of Strength Via Temperature for SiC/SiC Composites and SiC Fibers in an Oxygen-Free Environment

Abstract

The sensitivity of strength via temperature for SiC/SiC composites and SiC fibers in an oxygen-free environment is studied through experimental investigation and theoretical analysis. Tensile tests are performed on SiC/SiC minicomposites at room temperature, 500 and 1000 ℃ in an oxygen-free environment. A high-efficiency method is proposed to obtain the high-temperature strength distribution of SiC fibers. The experimental results show that the sensitivity of strength via temperature is high for SiC fibers but low for SiC/SiC minicomposites. To explain this phenomenon, the strength model of minicomposites is developed. The theoretical analysis reveals that the low sensitivity of strength via temperature for minicomposites results from that the influences of the changes of the Weibull parameters m and σ0 at elevated temperatures are offset.