Fracture mechanical evaluation of the effects of grinding residual stresses on bending strength of ceramics

In order to evaluate the effects of grinding residual stresses on bending strengths, the near-surface distributions of grinding residual stresses of differently ground Al2O3 samples were determined non-destructively by means of depth-resolved X-ray residual stress analyses. It was found that the compressive surface residual stresses increase with increasing single grain cutting depth. In parallel, an increase of the four-point bending strength of the samples was observed. Its magnitude was compatible with the increase of bending strengths expected from the residual stress intensity of the grinding residual stresses acting on the failure critical defects.