The effect of stress waveform on the cyclic fatigue behavior of Y2O3 PSZ was investigated and the following conclusions were obtained.
(1) The cyclic fatigue behavior was independent of frequency in the range from 30Hz to 550Hz under the same stess waveform.
(2) By evaluating the stress waveform effect on the basis of an empirical equation of subcritical crack growth rate, the predicted line was found to agree well with the experimental one under the modified rectangular pulse wave and sinsuoidal wave for the case of stress amplitude ratio R=0.8.
(3) In the case of R=0.7, however, the experimental line shifted toward longer life than the predicted one. The shift magnitude was independent of frequency and dependent on stress waveform.