MoS₂ additive to the MAO Al₂O₃ composite coatings with enhanced mechanical performances

MoS₂-Al₂O₃ composite coatings were fabricated on aluminum alloy substrates by micro-arc oxidation in silicate electrolytes doped with different concentrations of MoS₂ micro particles. MoS₂ (3)-Al₂O₃ composite coating showed more compact and smooth structure and thus the least scattering distribution of the hardness values. It was found that the friction and wear resistance of composite coating could be improved with increasing MoS₂ particles in a range of 1 ∼ 3 g l⁻¹. MoS₂ (3)-Al₂O₃ showed low and steady friction coefficient value of 0.655. The friction and wear resistance of composite coating was impaired with further addition of MoS₂ particles with the appearance of obvious oscillation in the friction coefficients. The friction and wear mechanism for the MoS₂ (3)-Al₂O₃ composite coating was thoroughly studied. (paper)