Effect of Y2O3-stabilized ZrO2 whiskers on the microstructure, mechanical and wear resistance properties of Al2O3 based ceramic composites

The aim of this study was to improve the mechanical properties of Al 2 O 3 ceramics by the addition of Y 2 O 3 -stabilized ZrO 2 whiskers (designated as Al 2 O 3 /YSZ W composite) through the flux method and hot-pressing technology. The effect of YSZ W content on their microstructure , phase composition and transformability, mechanical properties, and wear resistance was systematically investigated. The Al 2 O 3 /YSZ W composites containing 10 wt% YSZ W exhibited the best mechanical performance, including the highest content of YSZ W tetragonal phase and transformability as well as the largest values in their relative density (99.5%), hardness (1969 HV), fracture toughness (9.57 MPa m 1/2 ) and flexural strength (855 MPa). The strengthening and toughening of the Al 2 O 3 /YSZ W composites were attributed to the YSZ W tetragonal-monoclinic phase transformation as well as the whiskers reinforcing effect. Furthermore, the Al 2 O 3 /YSZ W composites also showed the highest friction and wearing properties.