Fabrication of wear-resistant and superhydrophobic aluminum alloy surface by laser-chemical hybrid methods

To achieve rapid, efficient, and low-cost preparation of large-scale stable aluminum alloy superhydrophobic surfaces, a new preparation method is proposed. The outer surface of the array micro-protrusions was coated with a layer of armor, which was the molten spatter produced during picosecond laser processing. The molten sputters and micro-protrusions combined to form micro–nano composite multi-layer structures. Through these special array micro–nano composite multi-layer structures and chemical modification, the wear-resistant and superhydrophobic properties of aluminum alloy surfaces were realized. According to test results, the array micro–nano composite structures prepared by picosecond laser and chemical modification had a water drop contact angle of 154.6° and a water drop rolling angle of 2°, exhibiting excellent superhydrophobic and anti-adhesion properties. Its self-cleaning, corrosion resistance and friction and wear behavior were systematically analyzed. The analysis results showed that the rolling droplets on the prepared surface could easily take away contaminants. The corrosion voltage and corrosion current density of the prepared superhydrophobic surface are significantly lower than that of the raw surface. In addition, a water drop contact angle of the aluminum alloy sample maintained at 145.1° after five wear tests, indicating the prepared surface after wear testing still had hydrophobic performance. The innovative method proposed in this study provides a simple and effective method for preparing large-scale wear-resistant superhydrophobic surface of aluminum alloy.