Abstract
R-curve behavior of zirconia has been already reported by many researchers. On the other hand, the effect of cycling stress on cyclic fatigue behavior of zirconia has been also confirmed. It is important for the lifetime prediction on fatigue to make clear the correlation between the stress cycling effect and R-curve behavior. In this work, K_1-V curve of stabilized zirconia was obtained by crack length measurement method using thin metal film for indentation small crack. Also a rising R-curve could be obtained from stable crack growth by three point bend with the 0.025 mm/min for the small crack. The lifetime prediction for cyclic fatigue was obtained by assuming that the rising R-curve behavior is due to the crack tip closure disappeared by the cyclic load. The predictions could well explain the experiments.