Sliding Wear Performance of Plasma-Sprayed Al2O3-Cr2O3 Composite Coatings Against Graphite under Severe Conditions

Al₂O₃, Cr₂O₃, and Al₂O₃-Cr₂O₃ composite coatings were produced by plasma spraying. Their tribological properties were evaluated at high load conditions. The average friction coefficients, wear rates, and worn surface temperatures of the coating/graphite pairs were measured. Compared with the single coating/graphite pairs, the friction coefficients of composite coating/graphite pairs are more stable. The corresponding wear rates and worn surface temperatures are lower, which may be conducive to the formation of more effective and stable graphite transfer film on the surface of the coating subjected to abrasion. Especially, 10wt.%Al₂O₃-90wt.%Cr₂O₃ (AC₉₀) composite coating shows better anti-wear performance, which may be attributed to its higher thermal conduction.