Fabrication Technology Of Superhydrophobic Metallic Surface And Analysis Of Wetting Mechanism

This paper present a single-step method to fabricate superhydrophobic surfaces on brass and aluminum alloy using reciprocating type high speed wire cut electrical discharge machining (HS-WEDM). SEM studies exhibit that a multi-scale structure is fabricated in the metal surface, the structure on aluminum alloy is composed of submilimeter-groove, micron-sized bumps and nano-porous, while the structure on brass is composed of submilimeter-groove, micron-sized bumps and nano-convex. After testing, the contact angel on the resulting surface of aluminum alloy arrived162degrees, while contact angel on the resulting surface of aluminum alloy arrived172degrees. In order to describe the wetting state for the multi-scale structure presented here, we theoretically infer eight different mathematical models for wetting states with decoupling of submilimeter-, micro-and Nanoscale roughness in multi-scale structure, according to the Young’s equation, Wenzel equation and the Cassie equation. The experimental results and the theoretical results are consistent. This method is simple, effective, and does not need of special equipment or complex processing. So it has great potential for further applications in industry.