Semplified Equation for Evaluating the Influence of Surface Residual Stresses on Toughness of Zirconia Ceramics

A simplified theoretical equation was developed to estimate the influence of a thin surface layer with a nonuniform profile of residual compressive stress on indentation cracking. The model was used to evaluate the toughness of tetragonal zirconia polycrystals that had been doped with 3 mol% yttria (3Y-TZP), which contained surface residual stresses due to phase transformation.