Examination of Prestress on Fatigue Life Effect in Partially Stabilized Zirconia

Abstract

　　　In our previous study the method adding prestress before cyclic loading were suggested to improve the degradation in cyclic fatigue life-time of partially stabilized zirconia. The test results indicated that the method could make the lifetime appreciably increase in cycling fatigue with a low applied stress. In this study, in order to examine more effective pre-loading conditions for the fatigue life increase the cyclic fatigue tests changing prestresses by two types pre-loading methods were conducted. Furthermore, SEM observations, X-ray diffraction, and ultrasonic measurements were also used for the examination. As a result, it was found that adding the prestress close to transformation stress was more effective for fatigue life increase, because the prestress promoted the occurrences of microcracks in the neighborhood of main crack extended during cyclic loading.