Effects of Solid Lubricants on Tribological Behaviour of APSed Al2O3-ZrO2 Composite Coatings

This study focuses on the fabrication of the self-lubricating ceramic composite coating layers with low friction components at high temperatures. Al2O3-15 wt% ZrO2 coatings, that contain solid lubricants such as CaF2, BaF2, h-BN, MoS2, and WS2, are deposited using the atmospheric plasma spray (APS) method at a gun power of 41400W, and their tribological behaviours are investigated. BaF2, MoS2, and WS2 decompose to beta-Ba, Mo, and W, respectively, during the APS coating process. The friction coefficients of the deposited Al2O3-15 wt%ZrO2 composite coating layers are in the range of 0.35 to 0.65. The tribological behaviors of the APSed Al2O3-15 wt% ZrO2-solid lubricant composite coating layers are dominated by the formation of transfer films of wear debris and microcracking during sliding.