Thermal Stress Failure of Ceramics under Repeated Rapid Heatings

A plasma jet thermal shock testing method was developed for evaluating the mechanical response of ceramics to repeated thermal shock heat up. The extent of damage involving changes in the populations of critical microstructural heterogeneities was characterized through statistical distributions of residual strengths. This thermal shock testing method was applied to silicon-based ceramics, including two grades of silicon nitride and a commercial silicon carbide. The thermal fatigue behavior was finally simulated using failure probability computations produced by the CERAM computer code for reliability analysis.