Preparation and tribological performance of MoS2 nanoparticles supported on fly ash microparticles

Purpose This paper aims to explore the preparation and tribological performance of MoS2 nanoparticles supported on fly ash (FA) microparticles. Design/methodology/approach FA was activated by NaOH, oleic acid and HCl to obtain three modified FA samples. Nano-MoS2 was deposited on them to form MoS2/FA additives for poly-alpha-olefin (PAO) modification. Tribological tests were conducted on a reciprocating rig through the ball-on-disk friction manner. Using X-ray diffraction, scanning electron microscope, energy dispersive spectrometer, Raman spectrometer and element analyzers, the products and their lubrication mechanisms were characterized. Findings At 1.5 Wt.%, nano-MoS2 and MoS2/FA could remarkably improve the tribological properties of PAO. The nano-MoS2 deposited on the HCl-activated FA presented better lubrication performance than nano-MoS2. It could reduce friction and wear by approximately 27% and approximately 66%, respectively. The lubrication of MoS2/FA can be attributed to the formation of MoS2 and carbon containing lubricating film. Originality/value FA was applied as a supporter to prepare MoS2/FA lubricants. The reuse of FA, a solid waste, is important for environmental protection. Moreover, MoS2/FA is more economical than nano-MoS2 as a lubricant, because it contains approximately 71% of low-cost FA.