Static and cyclic fatigue limits of alumina ceramics

Static and cyclic fatigue tests were performed on alumina using smooth-surf ace flexure specimens under several constant stress levels, The fatigue lif etimes, including imperfect data, were analyzed statistically to estimate t he original distributions of the lifetimes, A technique for estimating the static and cyclic fatigue limits was proposed using the residual strength o f the specimens surviving after the running time. The effects of cyclic str ess on fatigue crack extension were confirmed experimentally by comparing t he stress-lifetime curves obtained in the static and cyclic fatigue tests o n smooth-surface specimens.