Wear resistance of molybdenum disulfide-based coatings on titanium alloys: a review

With the rapid development of the global aerospace industry, higher requirements have been placed on the comprehensive performance of structural materials for aviation. Among them, titanium alloys are widely used in the design of rocket engine casings, rocket nozzle conduits and artificial satellite casings because of their high strength, good corrosion resistance and high heat resistance. However, the surface of titanium alloy has poor wear resistance, which makes it difficult to adapt to its practical use in the aviation environment, especially in high-temperature and wide-temperature conditions. Researchers have found that the preparation of molybdenum disulfide solid lubrication coatings on the surface of titanium alloys can significantly improve this problem. This review summarizes the research progress of MoS2-based material coatings, which contains the design of MoS2-based coating components, and the preparation methods of MoS2-based coatings. Therefore, the unitary, binary, diversified and multilayer designs of molybdenum disulfide-based materials in coatings are discussed. In addition, the current preparation methods of MoS2-based materials are reviewed, focusing on the improvement of wear resistance of titanium surfaces by MoS2–Ti coatings as well as plasma electrolytic oxidation (PEO) technology. Finally, the advantages and disadvantages of the current research on molybdenum disulfide-based materials are summarized, aiming to provide some references for the practical application of titanium alloys in the aerospace field.