Processing of Homogeneous Zirconia‐Toughened Alumina Ceramics with High Dry‐Sliding Wear Resistance

The preparation of dense homogeneous zirconia‐toughened alumina (ZTA) with high dry‐sliding wear resistance is described. These ZTA ceramics are obtained by sintering green compacts, made by colloidal filtration of well‐defined ZrO 2 ‐Al 2 O 3 particle suspensions, for 2 h at 1400°C. The optimum solid and stabilizer concentrations for the filtration process were determined. The sintered ZTA microstructure consists of a homogeneous distribution of zirconia grains in an alumina matrix with grain sizes of 0.2 and 0.5 µm, respectively. In pin‐on‐disk tribological measurements at relatively high initial contact pressures (1130 MPa) and sliding speeds (0.5 m/s) a very low specific wear rate (about 5 × 10 ‐8 mm 3 /(N·m)) and a coefficient of friction of 0.45–0.55 were found. It is shown that, in this case, wear is dominated by abrasion and polishing.