Preparation And Tribological Properties Of Tungsten Disulfide (ws₂) Film

Great challenges have been confronted with the lubricant in severe operating environments (e.g., high temperature or vacuum, or circle between high & low temperature) where lubricating oil cannot be used. Solid lubricating films are often applied as an alternative lubricant and are finding greater practical uses in the fields of vacuum equipments, aviation and space applications. Due to excellent tribological properties and higher oxidation resistance temperature than MoS2, WS2 has been practical solution for more rigorous application occasion.The tungsten disulfide (WS2) films were prepared on 3Cr13 stainless steel by two methods including DC reactive magnetron sputtering & sulfide and RF magnetron sputtering. The morphology, microstructure and chemical component of WS2 films were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscope (EDS) respectively. Scratch tests were performed to determine the adhesion of as-deposited films with the substrates. The thinkness of the films was measured by contact pin. The tribological properties of the WS2 films were tested by multi-specimen test system.It is found that the thin films can be amorphous films can also be a crystallization by the analysis of XRD. The quality percentage and the atomic percentage of S, W element are measured by the analysis of EDS. The analysis data reveal that the structure and the composition of WS2 film are determined by different experimental parameters. And by spectra of SEM, it is noted that WS2 films are very smooth and compact. The results of DC reactive magnetron sputtering & sulfide show that sulfide temperature can significantly affect on the surface of WS2 film and crystallization rate, but little affect on the chemical composition. RF magnetron sputtering results show that the interlayer can improve the adhesion of as-deposited films with the substrates, after annealing the film trends to be a crystallization. The relationship between the morphology, microstructure, chemical component and the adhesion of WS2 films under different preparation parameters (such as sulfide temperature deposition power, deposition pressure, deposition time and interlayer) were studied.The tribological properties for WS2 films were investigated by multi-specimen test system. The different effects on the friction behavior were discussed. The results show that DC reactive magnetron sputtering & sulfide can improve the tribological properties for 3Cr13 stainless steel, with the curing temperature increasing, the tribological properties improve. The RF magnetron sputtering, the tribological properties of the different parameters have been studied. Through the study of different interlayer, it is found that interlayer can improve the quality of films. In this paper, the WS2 films with interlayer have better performance, the interlayer can reduce stress within the film and enhance the adhesive strength markedly. The WS2 films with interlayer have lower friction coefficient and little effects by different loads.