A high-efficiency preparation method of super wear-resistant superhydrophobic surface with hierarchical structure using wire electrical discharge machining

Abstract

Superhydrophobic surface has extensive application prosperity for in aerospace, shipping, armament and other fields due to its excellent performance, such as anti-icing, self-cleaning, metal corrosion resistance, oil/water separation. However, because of complex preparation process and wear resistance, the engineering application of superhydrophobic surfaces is limited. To address this issue, this paper proposes a high-efficiency preparation method of super wear-resistant superhydrophobic surface with hierarchical structure using wire electrical discharge machining (WEDM). Firstly, the single-step preparation principle of hierarchical structure using WEDM is introduced, which is consists of micron-grade discharge morphology and submillimeter-grade surface texture. Secondly, the preparation process of micron-grade discharge morphology is investigated to obtain the maximum apparent contact angle (ACA). It was found that the micron-grade discharge morphology and the absorbed organics can increase apparent contact angle from 75.5° to 121°. Additionally, the preparation process of submillimeter-grade surface texture is studied to obtain the best triangular surface texture. A gas-liquid-solid contact angle (CA) simulation model is established to analyze the effect of the surface texture size on the contact angle. The experimental results show that the maximum contact angle can be up to 156.5° through combining the maximum apparent contact angle with the best triangular surface texture. The simulation data of contact angle shows a good agreement with experimental data. Finally, the prepared superhydrophobic surface is proved to be of excellent time durability and wear resistance. This study can provide some guiding value for preparing super wear-resistant superhydrophobic surface.