Effect of Microstructure on the Tribological and Mechanical Properties of CuO‐Doped 3Y‐TZP Ceramics

Dense 8 mol% CuO‐doped 3Y‐TZP ceramics were prepared by pressureless sintering for 8 h at 1500° and 1550°C, respectively. Transmission electron spectroscopy revealed that the ceramic sintered at 1500°C exhibits grain boundaries free of any amorphous phase, while crystalline copper‐oxide grains were found in the zirconia matrix, whereas the sample sintered at 1550°C contains a Cu‐rich amorphous grain boundary layer. The tribological behavior of these materials was tested under dry‐sliding conditions using a pin‐on‐disk tribometer. The material sintered at 1500°C showed self‐lubrication resulting in a low coefficient of friction ( f ) of 0.2–0.3 and a low specific wear rate ( k ) ≪ 10 −6 mm 3 ·(N·m) −1 . In contrast, the material sintered at 1550°C showed poor tribological behavior ( f =0.8–0.9; k ≫ 10 −6 mm 3 ·(N·m) −1 under the same conditions. The difference in the tribological behavior of these two materials was interpreted on the basis of mechanical properties and microstructural characteristics.