Fabrication of durable superamphiphobic aluminum alloy surfaces with anisotropic sliding by HS-WEDM and solution immersion processes

The submillimeter-scale structures were fabricated by the high speed wire electrical discharge machining (HS-WEDM) technology on the 5083 aluminum (Al) alloy substrates. The results showed that the V-shaped groove arrays with a hierarchical structure presented the good superamphiphobicity after a solution immersion, in which the contact angles (CAs) achieved 154.70°, 154.55°, and 153.92° for water, glycerol, and ethylene glycol being, respectively. The effect of the sizes of V-shaped groove on wettability was discussed, this result may be useful for the design of controllable surfaces. In addition, a functional surface with the obvious anisotropic (the directions of the parallel and perpendicular for the grooves) sliding property revealed for water/oil may be expected to obtain potential applications in droplet-directional transportation, fluidic control, and so on. After peeling and mechanical tests the Al surfaces still exhibit superamphiphobic properties. Furthermore, the HS-WEDM technique is efficient and large area three-dimensional for building rough surface. Hence, it can be potentially suitable for industrial production of durable superamphiphobic Al surfaces with anisotropic sliding.