Abstract
High temperature flexural fatigue behavior was investigated on Si3N4 ceramics at 1173K and 1273K. The present study was focused on examining a beneficial effect of compressive loading on fatigue resistance. Fatigue resistance of smoothed samples was found to increase under fully reversed loading beyond those under pulsating loading and sustained loading. Crack growth tests were made to understand this behavior. Enhanced resistance under reversed loading was observed among sustained, pulsating and reversed loading. Compressive loading caused a recovering effect for the damage at crack tips, resulting in the beneficial effect on the high temperature fatigue resistance of smoothed samples under fully reversed loading.
