Fabrication of robust superhydrophobic surface on TC4 alloy by wire electrical discharge machining.

Superhydrophobic metal surfaces have significant applications in various areas such as surface self-cleaning, resistance reduction, anti-corrosion, etc. However, inexpensive preparation methods for superhydrophobic surfaces with a good mechanical stability are still to be developed. In this study, microarray structures on TC4 alloy were readily fabricated using a wire electrical discharge machining technology. Following the treatment with a fluorinating reagent, the microarray surface exhibited excellent superhydrophobic properties, where the largest contact angle and the smallest sliding angle reached 159° and 3°, respectively. Influences of the dimensions of microarray structure on the TC4 alloy surface wettability were also investigated in this study. Experiments show that this superhydrophobic surface possesses favorable self-cleaning, good mechanical stability, and promising anti-corrosion properties. In addition, by controlling the dimensions of the microstructure a superhydrophobic surface with a gradient wettability was also fabricated, which exhibits the property of doing nondestructive transportation of liquids. • Superhydrophobic surface on TC4 alloy surface is realized by using low-cost wire electrical discharge machining. • The influences of microarray structure size on surface wettability are systematically analyzed. • The prepared superhydrophobic surface has excellent mechanical stability, corrosion resistance and self-cleaning effect. • The gradient superhydrophobic surface is achieved by adjusting the dimension of the microarray structures. [ABSTRACT FROM AUTHOR]