Effects of CuO nanoparticles on friction and vibration behaviors of grease on rolling bearing

To evaluate the effects of CuO nanoparticles on friction and vibration behaviors of grease on rolling bearing, lithium complex grease (LCG), polyurea grease (PG), calcium sulfonate complex grease (CSCG) and these three greases containing 1 wt% CuO nanoparticles were prepared respectively. The microstructure, friction coefficient, wear surface and bearing vibration test of six greases were investigated in detail. The results show tribological properties of PG are improved most significantly, with the friction coefficient and wear scar diameter decrease, and the wear surface is fine and smooth. This is mainly attributed to the synergistic effect of lamellar thickener structure and CuO nanoparticles. Further, the addition of CuO nanoparticles to PG also has an obvious inhibitory effect on bearing vibration. •The three thickeners show coiled fibrous, lamellar and reticular microstructure.•The CuO nanoparticles have different effects on friction of the three greases.•The CuO nanoparticles affect the vibration of bearing with three greases.