Wear behaviour of alumina toughened zirconia materials

This study presents correlations between, on the one hand, wear rates and wear mechanisms and, on the other, toughness and microstructure of highly reactive alumina-based materials containing 0 to 24% partially stabilized zirconia using 1.5% yttria (Y-PSZ). All samples were sintered to 97.5% of their theoretical density (+/-0.5%). A 4 x 4 Latin square design of experiments was followed. Wear resistance was measured using a ring-on-disc experimental set-up that was conceived to measure volumetric wear and dynamic coefficient of friction under constant sliding speed of an unlubricated contact. Results obtained at a speed of 0.26 m s(-1) within a range of applied loads of 50 to 200 N showed that the optimal values of Y-PSZ content needed to minimize the wear rate were a function of these applied loads; the optimal amount of Y-PSZ required to obtain the maximum wear resistance, within the boundaries of the present study, varied from 8% at 200 N to 16% at 50 N. The main wear mechanism changed abruptly from abrasion to chipping above 100 N. As expected, toughness was not the only criterion to predict wear resistance; microstructure control was also important.