Wettability and mechanism analysis of strengthened micro-nano structure on Ti6Al4V surfaces with microporous and nanoparticles by laser-belt machining

Micro-nano structures have widely applied in functional surfaces, but the structures are susceptible to damage and loss of functional applications. In this study, the sinusoidal micro-nano structures were fabricated on the Ti6Al4V alloy surfaces by laser-belt machining (LBM). The surface morphology and wettability were analyzed, and the mechanical durability of the surface was explored. The results revealed that by optimizing the process parameters, high-efficiency and low thermal damage processing of micro-nano structures could be achieved. After storing the machined samples in the air for 30 days, hydrophobicity was realized through the adsorption of carbon element and the feature of the micro-nano structures. The contact angle of the laser processed surface reached 127.57°. However, the LBM removed the rated height of the structures, causing an overall downward trend in the contact angle. Under the optimal process parameters, the residual compressive stress processed by LBM was 4.5 times higher than that of laser processing, which could better withstand mechanical durability. The LBM method provides new insights for the strengthening the surface of micro-nano structures.