Fabrication and Stability of a Fluorine-Free Superhydrophobic Self-Cleaning Surface on 3003 Aluminum Alloy

To improve the antifouling and self-cleaning performance of 3003 aluminum alloy, a green fluorine-free superhydrophobic surface was fabricated by combining nanosecond laser processing with subsequent heat treatment. The effects of laser processing parameters, including scanning speed, laser power, pulse frequency, and scanning interval, on surface wettability were systematically investigated. The results showed that optimized processing conditions (2700 mm/s, 6 W, 35 kHz, and 20 μm) enabled the formation of hierarchical micro-/nano-structures, resulting in a maximum water contact angle of 154.32°. SEM and EDS analyses suggested that the enhanced wettability originated from the synergistic effect of hierarchical rough structures and heat-treatment-induced surface chemical modification, which promoted the formation of a stable Cassie–Baxter state. The fabricated surface exhibited excellent self-cleaning performance, as water droplets effectively removed SiO₂ contaminants by rolling behavior. In addition, the surface maintained high hydrophobicity after repeated water jet impact and tape-peeling tests, indicating good resistance to dynamic flow and mechanical damage. This study provides a simple, environmentally friendly, and effective strategy for fabricating durable superhydrophobic aluminum alloy surfaces for antifouling and protective applications.