Effect of applied load on the tribological properties of MoS₂–Ti_L/MoS₂–Ti_H nano-multilayer coating

MoS2–TiL/MoS2–TiH coating (L and H are low and high power of the sputtered Ti target) possesses excellent tribological properties owing to its nano-multilayer structure. In this study, the tribological properties of MoS2–TiL/MoS2–TiH coating were extensively analyzed at different loads. Relative to the MoS2–Ti monolayer coating, the nano-multilayer structure not only improved the wear resistance but also increased the critical load at which the coating began to peel off. The MoS2–Ti coating maintained its lubrication only in the early stage of the test even at a load of 2 N. In contrast, the friction coefficient and wear rate of the multilayer coating were small and stable until the load reached 20 N. The critical load of the optimized MoS2–TiL/MoS2–TiH coating was 10 times that of the MoS2–Ti coating. At excessive loads, the multilayer coating lost its lubrication in the early stage of the test because the coating was completely worn off under such loading.