Using a block-on-ring tribometer with the revolving motion of high chromium cast iron (HCCI) ring against Al2O3 dispersed Y-TZP ceramics (ADZ) blocks, the wear resistance of ADZ ceramics with different grain sizes of ZrO2 was investigated at room temperature. The results show that there was no direct relation found between the grain size and the wear resistance of ADZ ceramics. The tetragonal (t) monoclinic (m) martensitic transformation occurred during the friction process. Only for suitably sized t-ZrO2 particles, the tm martensitic transformation occurred under the action of the frictional stress, and the phase transformation is beneficial for the wear resistance of ADZ ceramics. When the grain size of t-ZrO2 particles is too small, no phase transformation toughening occurred. Moreover, many microcracks will be created by the phase transformation if the grain size is big enough. Then, these microcracks lead to fracture and have a negative effect on the wear resistance of ADZ ceramics.

Keywords: Y-TZP/Al2O3 ceramics; grain size; wear resistance