Preparation and Tribological Properties of Carbon-Coated WS(2) Nanosheets

WS(2)-C is produced from a hydrothermal reaction, in which WS(2) nano-sheets are coated with carbon, using glucose as the carbon source. In order to investigate the tribological properties of WS(2)-C as a lubricant additive, WS(2)-C was modified by surfactant Span80, and friction tests were carried out on an MRS-10A four-ball friction and wear tester. The results show that Span80 can promote the dispersibility of WS(2)-C effectively in base oil. Adding an appropriate concentration of WS(2)-C can improve the anti-wear and anti-friction performance of the base oil. The friction coefficient reached its lowest point upon adding 0.1 wt % WS(2)-C, reduced by 16.7% compared to the base oil. Meanwhile, the wear scar diameter reached its minimum with 0.15 wt % WS(2), decreasing by 26.45%. Moreover, at this concentration, the depth and width of the groove and the surface roughness on the wear scar achieved their minimum. It is concluded that WS(2)-C dispersed in oil could enter friction pairs to avoid their direct contact, thereby effectively reducing friction and wear. At the same time, WS(2)-C reacts with the friction matrix material to form a protective film, composed of C, Fe(2)O(3), FeSO(4), WO(3), and WS(2), repairing the worn surface.