Tribological Properties of Nano-Sized Molybdenum Disulfide Particles

This paper summarizes the tribological properties of MoS₂ nano-particles with about 30 nm under different frictional conditions. By four-ball tribometer, the results showed that as the nano-MoS₂ content is over 0.5 wt% the extreme pressure of lubricating oil is higher than to 30% than that of lubricating oil with same content of common MoS₂. The nano-MoS₂ particles can decrease the friction coefficient of lubricating oil obviously. However the results showed that their friction reductions have not obvious difference by the ring-on-block tribometer. The analyses of surface composition conducted by XPS and SEM images showed that the nanoparticles form a protective film (WO₃) allowing an increase in the load capacity of rubbed pairs. The main advantage of the nanoparticles is ascribed to the release and furnishing of the nanoparticles from the valley onto the rubbing metal surface and their confinement at the interface.