Influence of surface texture directionality and roughness on wettability, sliding angle, contact angle hysteresis, and lubricant entrapment capability

摘要

This work emphasizes on assessing the influence of surface texture directionality and roughness on the lubricant wettability, flowability and entrapment capability of engineering surfaces. Experimental results using Contact Angle Goniometer show that the wettability increases with an increase in roughness in the higher roughness range of-Ra 886 to 236 nm and with a decrease in roughness in the lower range of-Ra 151 to 79 nm. The critical sliding angle and critical contact angle hysteresis were obtained at lower sliding-angles when the directionality in texture was parallel to the sliding direction. In near Wenzel mixed-wetting conditions, surfaces having individual entrapment sites (8G texture) revealed better lubricant entrapment capability with up to-22% entrapment.