MoS2-based self-lubricating coating of many excellent properties has broad application in aerospace and civil fields. MoS2 coating is loose and easy to be oxidized at high temperature and humidity. Since rare earth elements have the effect of inhibiting grain growth and coarsening in the material, Ti doping has been widely proven to effectively regulate the coating structure. In order to solve this problem, the effect of Ce-Ti alloy target power on tribological properties of MoS2-based coatings was investigated to prepare MoS2-based self-lubricating coatings with excellent dry friction properties. The effect of the power of the alloy on the microstructure, mechanical properties, and tribological properties of Ce-Ti/MoS2 coating was studied by dc and RF dual-target non-equilibrium co-sputtering technology. The doping content of the coating was controlled by adjusting the power of the Ce-Ti (1∶1) target. The composition, crystal phase structure, and microstructure of the coating were analyzed by field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), atomic force microscopy (AFM), and grazing incidence X-ray diffraction (GIXRD). The mechanical properties of the coating were tested with nano indentation apparatus. The friction and wear properties of the coating were characterized by a friction and wear testing machine, a white light interferometer, and a Raman spectrometer. The composition changes of the coating surface and wear marks were analyzed. The coating initially grew in (002) preferred orientation, accompanied by (100), (105) and (110) three growth orientation MoS2 characteristic peaks. With the increased power of the doped metal, the crystal structure of the MoS2 coating became similar to the amorphous structure. The surface changed from pure MoS2 vermicular shape to fine aggregate shape gradually, and the aggregate size became coarse after reaching 90 W power. The factor coefficient and wear rate decreased first and then increased. When the deposition power of Ce-Ti target reached 70 W (Ce: 2.32 at.%, Ti: 7.21 at.%), the densification of Ce-Ti target changed from undoped porous columnar crystal to fine columnar growth structure, the nano-hardness reached 7.85 Gpa, and the oxidation phenomenon was obviously improved. In terms of friction and wear, the wear mark showed micro abrasive wear at 70 W power, the average friction factor was as low as 0.073, and there was no apparent sharp increase. In the process of friction, the coating did not produce evident adhesion and plastic fracture, and the wear rate was reduced to 9.42× 10–8 mm3N–1m–1. The steel balls formed transfer films, which effectively reduced the shear force in the friction process. Under the condition of 70 W, the area of transfer film was the smallest, which slowed down the adhesion between interfaces. The MoS2 structure was reconstructed at the wear mark during friction, which significantly reduced material's friction factor and wear rate. Magnetron sputtering Ce-Ti doped MoS2 based coating improved the compactness and friction and wear performance of the coating and achieved the optimal comprehensive performance when the power was up to 70 W, and the friction factor and wear rate of the coating was significantly reduced. © 2023 Chongqing Wujiu Periodicals Press. All rights reserved.
