Experimental evaluations on tribological performance of oil-based WS_2 nanofluid applied on steel/brass friction pairs

摘要

The present research evaluated the tribological performance of oil-based WS_2 nanofiuids applied on steel-brass friction pairs. It was found that the coefficient of friction could be reduced by up to 39%, and the wear width and depth could be reduced by up to 28.7% and 66.4% using 1 wt% WS_2 nanofluid. While using the WS_2 nanofiuids, almost no adhesive wear was detected on the worn surfaces. By analyzing the chemical compositions, carbon percentage increased after engaging the oleic acid which suggested tribo-films with low shear resistance were formed. In addition, elements of sulfur and tungsten were found within the wear track lubricated by WS_2 nanofiuids. It was believed that the WS_2 nanoparticles were involved in the formation of the tribo-layers and mixed with the oleic acid tribo-films to improve the tribological behavior. Moreover, the tribo-layers produced by the WS_2 nanoparticles could provide solid lubricating and mending effects on the mating surfaces.