Wear properties of two-phase Al2O3/ZrO2 (Y2O3) ceramics at temperatures from 296 to 1073 K

Reciprocating sliding friction experiments were conducted with various two-phase, directionally solidified Al2O3/ZrO2 (Y2O3) pins sliding on B4C flats in air at temperatures of 296, 873, and 1073 K under dry sliding conditions. Results indicate that all the Al2O3/ZrO2 (Y2O3) ceramics, from highly Al2O3-rich to ZrO2-rich, exceed the main wear criterion requirement of 10−6 mm3 N−1 m−1 or lower for effective wear-resistant applications. Particularly, the eutectics and Al2O3-rich ceramics showed superior wear properties. The composition and microstructure of Al2O3/ZrO2 (Y2O3) ceramics played a dominant role in controlling the wear and friction properties. The controlling mechanism of the ceramic wear, friction, and hardness was an intrinsic effect involving the resistance to shear fracture of heterophase bonding and cohesive bonding and the interlocking microstructures at different scales in the ceramics.