Friction and Wear Properties of ZrO₂–Al₂O₃ Composite with Three Layered Structure Under Water Lubrication

Zirconia–Alumina (ZrO₂–Al₂O₃) composite with three layered structure was prepared, and its friction and wear properties under water lubrication were investigated. The results indicate that the layered composite exhibited better tribological properties comparing with ZrO₂–Al₂O₃ mono-layered composite at same tested conditions. Good combination of toughness and strength as well as subsequently excellent friction and wear properties were mainly contributed to the residual stress of the layered composite, which caused by thermal mismatch of sintering between layers through special design of compositions and structure. Friction coefficient and wear rate of the layered composite decreased with increment of load and/or velocity. The change of tribological properties was also relative to wear mechanisms, micro-cutting, and abrasive wear were main mechanisms at lower load and/or lower velocity but fatigue wear caused by plastic deformation became dominant at higher load and/or higher velocity.