Tribological behavior and wear mechanism of TiO2/MoS2 nanocomposite coatings fabricated on TC6 alloys by micro-arc oxidation and duplex surface technologies

The TC6 alloy is featured with its lightweight nature, excellent corrosion resistance, and chemical stability, making it an ideal material for aerospace landing gear and transmission system. However, its low hardness and poor wear resistance significantly limit its reliability and service life. To address these limitations, wear-resistant and friction-reducing coatings were fabricated using micro-arc oxidation (MAO) and duplex technologies, such as MAO plus magnetron sputtering (MS), MAO plus cold spraying (CS) and single-step MAO with MoS₂ additive. The results show that the composite coatings with MoS₂ introduced via MS and CS exhibited enhanced lubrication properties, reducing COF to 0.245 and 0.099, respectively, while achieving wear rate reductions between 75.94 % and 92.51 %. Notably, the TiO₂/MoS₂ composite coating prepared via single-step MAO process achieved the highest hardness (684.65 HV) and the lowest COF (0.079), along with a 92.18 % reduction in wear rate. The synergistic effect of hard TiO₂ and MoS₂ enhances lubrication and wear resistance, providing a promising approach for improving the tribological performance of titanium alloys. These findings confirm that one-step composite MAO coatings effectively improve the tribological properties of TC6 alloy, making them promising alternatives for wear-resistant aerospace components.