HS-WEDM machining of superamphiphobic al surfaces and effect of the droplet size on wettability

In this study, superamphiphobic (SAP) aluminum (Al) alloy 5083 surfaces were produced with water/oil high contact angle (CA) greater than 150° and low sliding angle (SA). A simple and environmentally friendly technology of the high speed wire electrical discharge machining (HS-WEDM) was used to introduce submillimeter-, micro- and nano-scale structures, respectively, which resulted in a hierarchical morphology. Surface energy was reduced by coating with 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDTES) on the structured surfaces. The CAs approaching 154.80° for water, 154.55° for glycerol, and 153.92° for ethylene glycol were obtained after building hierarchical structures by HS-WEDM. The fundamental wettability models were used to explain the experimental results. The effect of the droplet size on the wettability of surfaces was also investigated. In addition, the SAP property of the Al surfaces is still exhibited after the stability, immersion, finger pressure and ultrasonic cleaning tests. SAP Al surfaces could see many wide potential applications including self-cleaning, anti-corrosion, anti-fouling, anti-icing and oil transportation.