Tribological Properties of Surface Wettability under Different Lubrication Regimes

In this study, the superhydrophobic surface and hydrophilic surface with micro-rough structure were prepared by using nanosecond ultraviolet laser with tin-bronze as substrate. The microstructure and surface wettability were characterized by scanning electron microscope and contact angle measuring instrument. The mechanism of variation of surface wettability of the prepared sample was analyzed by X-ray phototelectron spectrometer. The influence of the surface wettability on tribological properties under boundary and hydrodynamic lubrication regimes were investigated by measuring the friction coefficients on a UMT-2 friction and wear tester. The results show that the wettability of the material surface had a significant effect on the tribological properties under different lubrication regimes. Under boundary lubrication, the tribological properties of the hydrophilic surface were better than those of the hydrophobic surface, and the average coefficient of friction was reduced by 6.79%. Under hydrodynamic lubrication, the tribological properties of the hydrophobic surface were better than those of the hydrophilic surface, and the average coefficient of friction was reduced by 10%.