Effect of Working Pressure on Tribological Properties of Ce-Ti/MoS2 Coatings Using Magnetron Sputter

In preparing MoS2-based coatings by magnetron sputtering, the working pressure of the vacuum chamber directly affects the number and kinetic energy of sputtering particles, which causes a difference in coatings structure and performance. In this paper, MoS2 composite coatings with Ce and Ti binary doping were prepared by unbalanced magnetron sputtering technology, and the variation of composition, structure, and tribological properties of Ce-Ti/MoS2 coatings under different working pressures was studied. The results demonstrated that Ce and Ti doping improves pure MoS2 coatings. The Ce-Ti/MoS2 coatings reached the hardness of 9.02 GPa and the friction coefficient of 0.065 when working pressure was at 0.6 Pa. It was also observed that the deposition efficiency and wear rate reached the optimal value at 0.9 Pa. With the increase of working pressure, the columnar structure of the coating was coarse due to the change of kinetic energy and quantity of particles in the chamber. The intensity of the MoS2 (002) diffraction peak decreased, which eventually led to a poor lubrication effect and aggravated wear. This study provides technical guidance for preparing metal-doped MoS2 composite coatings with excellent mechanical and tribological properties.