Magnetron Sputtering If-of Mos <sub> 2 </ Sub> And Of Mos <sub> 2 </ Sub> / Mo Gradient Coating Friction And Wear Performance

In this work, Mo/Mo₂S₃/MoS₂ spherical structure and inorganic fullerene-like (IF) MoS₂ were synthesized. The microstructure and tribological properties of MoS₂ coatings obtained with sputtering nested target were investigated. The friction and wear behavior of MoS₂/Mo gradient coatings fabricated with magnetron sputtering method was also evaluated.The Mo/Mo₂S₃/MoS₂ were produced by first ball-milling 2H-MoS₂ powders to generate highly disordered amorphous MoS₂, followed by annealing the precursor at temperatures up to 850℃ for 5 h in mixed atmosphere of Ar and H₂. While 2H-MoS₂ was obtained after the precursor were annealed under the atmosphere without the existence of H₂.IF-MoS₂ was synthesized via decomposing the precursor that was obtained from the solution of thiomolybdate compound by a spray-drying method. The IF-MoS₂ was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscope (TEM). According to its morphology and microstructure, the formation mechanism of IF-MoS₂ was discussed combined with TGA-DTA method.The microstructure of the as-deposited coatings were examined by TEM. It was found that the coating deposited using 2H-MoS₂ target had long and orderly lamellar structure deposited. On the contrary, the coating using IF-MoS₂ target had shorter and more disorderly lamellar structure.The tribological properties of the MoS₂ coatings were investigated using a ball-on-disk tribometer in vacuum and in humid air. The MoS₂ coating deposited with IF-MoS₂ showed lower friction coefficient and higher wear resistance in different environments. The superior tribological performance of coating deposited with IF-MoS₂ is due to its unique structure, which is in favor of formation of spherical immediate lubricant by curling itself during the rubbing process.MoS₂/Mo gradient coatings with different Mo contents were also deposited on steel substrates, which were realized by adjusting initial power of Mo target with 30 W, 90 W and 120 W, respectively. In comparison of the adhere scratch of MoS₂/Mo gradient coatings and pure MoS₂ coating, it was found that all MoS₂/M0 gradient coatings showed better results of over 100 N. MoS₂/M0 gradient coating with initial Mo target power of 30 W exhibited almost the same friction coefficient as that of pure MoS₂ coating. Through analyzing the wear tracks of MoS₂/Mo gradient coating with initial Mo target power of 30 W and pure MoS₂ coating, it can be found that MoS₂/M0 gradient coating had better wear resistance.