A statistical fracture mechanics analysis of time-dependent strength behaviour of partially stabilized zirconia

The time-dependent strength behaviour of a partially stabilized zirconia ceramic (Mg-PSZ) when subjected to constant static and cyclic stresses as well as constant stress rates is analysed in terms of a statistical fracture mechanics model given earlier by the authors. Given the lifetimes for either constant static stresses or constant stress rates it is possible to estimate the lifetimes for constant cyclic stresses. There is good agreement between the predicted and actual lifetimes under cyclic stresses if the data for constant stress rates are used with the theory. The limitations of the conventional single-crack theory for lifetime predictions relative to the statistical fracture mechanics approach are highlighted.