The effect of WS2 nanoparticles on friction reduction in various lubrication regimes

A study of the tribological behavior of nested inorganic fullerene- like ( IF) nanoparticles of WS2, as a potential additive to base oils is presented. Friction measurement results obtained from three different test rigs over a wide range of normal loads and sliding velocities are shown. Stribeck curves are used to reveal the lubrication regimes where the IF are most effective. It is found that the addition of IF- WS2 nanoparticles to the base oils results in up to 50% reduction in friction coefficient in the mixed lubrication regime. The mechanism of improved friction and wear behavior with the IF additive is discussed.