THERMAL-SHOCK BEHAVIOR OF SILICON-NITRIDE FLEXURE BEAM SPECIMENS WITH INDENTATION CRACKS

The experimental results of thermal shock testing of silicon nitride flexure beam specimens containing indentation cracks are presented. The thermal stress induced by water quenching is much greater in the transverse direction than in the longitudinal direction, resulting in an insensitivity of residual bend strength to temperature differences up to 580-degrees-C. This result indicates that a flexure beam configuration is not an appropriate geometry for thermal shock testing when thermal shock behavior is to be evaluated from residual bend strength data.