Wear performance of MoS2 doped Al2O3 CPED coatings on TC6 titanium alloy

The innovative work presented in the paper focused on microstructures and wear performance of MoS 2 doped Al 2 O 3 coatings on TC6 alloy. Nano- and micron-sized MoS 2 particles doped Al 2 O 3 coatings (n and m-MoS 2 /Al 2 O 3 coating) were fabricated on TC6 alloy via cathodic plasma electrolytic deposition (CPED) technique. The microstructures and compositions of the coatings were characterized, the tribological behaviors were tested, and doping mechanism of MoS 2 particles was discussed. The results showed that, doped coatings were composed of α -Al 2 O 3 , γ -Al 2 O 3 and MoS 2 . The doping of MoS 2 particles promoted the transformation from γ -Al 2 O 3 to α -Al 2 O 3 during CPED process , and increased the compactness and crystallinity of doped coatings. The friction coefficients of TC6 alloy, Al 2 O 3 coating, n-MoS 2 /Al 2 O 3 coating and m-MoS 2 /Al 2 O 3 coating were about 0.7, 0.6, 0.55 and 0.45 in sequence, and the wear rates of n-MoS 2 /Al 2 O 3 coating and m-MoS 2 /Al 2 O 3 coating were about 75 % and 58 % of Al 2 O 3 coating. MoS 2 particles played the role of lubrication and contributed to improving wear performance of doped coatings, both friction coefficients and wear rates were declined, and micron-sized MoS 2 particles presented better wear performance than nano-sized particles.