Surface wettability pattern and shape gradient co-induced oil droplet directional transport for enhancement of lubrication performance

Thermo-capillary migration n lubrication systems is a phenomenon that the lubricant is migrated by the interfacial tension difference caused by ununiformed temperature generated by the wear behaviors, which leads to the lubricant starvation and results the severe damage. This paper proposed a novel method to eliminate the thermo-capillary migration phenomenon, in which we successfully fabricated a surface that combined shape gradient and wettability pattern on the 316L stainless steel, and the results proved that the prepared surface can not only effectively obstructed the liquid paraffin droplet migration but also directional transport the liquid paraffin to the center of the wear track under thermo-capillary migration effect. The results of wear tests further demonstrated that only the surface combine of shape gradient and wettability pattern can achieve a re-decrease of friction coefficient availably by means of external lubricant feeding in the state of lubricant starvation, which providing a strategy for improving and developing new types of lubrication enhancement for mitigating starvation lubrication.