Dislocation generation during the sliding wear of ceramics

The microstructure generated by the dry sliding wear of zirconia-alumina-silicon carbide composites has been examined by TEM. Basal slip, with b=1/3<1120>, was identified in the SiC. Slip in the alumina was confined to shallow grooves, but the damage did not cross phase or grain boundaries. Basal and pyramidal slip was dominant, but no evidence of prism slip was found. Widespread stress assisted transformation of tetragonal to monoclinic zirconia occurred. Under abrasive grooves the tetragonal had not transformed but had been extensively deformed, with a subgrain size down to ~50nm.