Temperature-dependent wear mechanisms in ZrO2-Ag-SrSO4 composite ceramics: The dominant role of Ag distribution

In response to the urgent demand for wide-temperature-range self-lubricating ceramics in demanding service environments, ZrO 2 -Ag-SrSO 4 composites with tailored Ag distributions were fabricated by oscillatory pressure sintering. The effects of Ag distribution (interface, matrix, lubricant phase) on the microstructure and tribological performance were investigated from room temperature (RT) to 1000 ℃. The results demonstrate that Ag and SrSO 4 can be incorporated into the ZrO 2 matrix, affecting interfacial bonding and frictional performance.The composite exhibits a low friction coefficient of 0.209–0.242 and a wear rate of (0.175–1.541) × 10 −5 mm 3 /(N·m). This is mainly attributed to Ag migration at low temperatures, Ag-SrSO 4 lubrication at medium temperatures, and formation of a SrSO 4 -Ag-NiO x tribofilm at 1000 ℃, enabling stable wide-temperature self-lubrication and providing high-performance tribological ceramic design.