Preparation of a superhydrophobic coating on 6061Al alloy substrate and its simplified truncated cone model.

Superhydrophobic materials are known for their vast range of applications and properties. We present a simple process to fabricate a superhydrophobic coating on 6061Al alloy via a route with chemical replacement and heat treatment. Through this route, a hierarchical morphology including microparticles and leaf-like microstructures was obtained and, upon modification by stearic acid, the prepared coatings show good water repellency with a water contact angle of 159.2 ± 0.3° and sliding angle of 4.5 ± 1.5°. Systematic studies have been conducted on the coatings fabricated under different processing conditions to obtain the best experimental parameters, and demonstrate the reaction mechanism and the good self-cleaning effect. The 3D simulated coating topography was characterized by Leica DCM 3D in the mesoscopic scale. Based on the topography, the simplified ideal truncated cone model and theoretical equation were obtained. According to the model, a qualitative result was drawn: the higher and sharper the convex structures are, the better is the superhydrophobicity. Furthermore, the presented process can be applied to larger, stable coatings with the controllable wettability for diverse applications. [ABSTRACT FROM AUTHOR]