Microstructure and Tribological Properties of TiAlSiN/TiAlAgN/Ti (Mo) N-MoS₂ Multilayer Coatings

Ti40Al20Si10, Ti48Al50Ag₂ and Ti-MoS₂ targets were used to prepare TiAlSiN/TiAlAgN/Ti(Mo)N-MoS₂ multilayer coatings. The surface morphology, microstructure, hardness and tribological properties of the coatings were studied by scanning electron microscope (SEM), X-ray diffractometer (XRD), microhardness tester, ball-disk friction and wear tester and surface profiler. The results show that the prepared multilayer coatings contained 0.62% (atomic fraction, the same below) Mo, 0.77% Ag and 30.05% Ti. The thickness of the coatings was about 3 μm, and the hardness was 21.09 GPa. At room temperature, the main lubricating agents were Si₂·H₂O water film, MoS₂ and a small amount of Ag. At 200 ℃, Ag and MoS₂ were the main lubricating agents. At 400 ℃, MoS₂ and a large number of Ag were lubricating agents. And at 600 ℃, Ag, Al₂O₃ and SiO₂ were the lubricating agents. Wear rates of the coatings at room temperature, 200 ℃, 400 ℃, and 600 ℃ were 0.0517×10^-3, 0.162 8×10^-3, 0.108 0×10^-3, 0.130 7×10^-3 mm³ / (N·m), respectively. TiAlSiN / TiAlAgN / Ti (Mo) N-MoS₂ multilayer coatings had good tribological properties at 400 ℃.