Fabrication of robust and durable superamphiphobic aluminum alloy and zinc surfaces via dual sandblasting and steam treatment

We present a scalable and environmentally friendly method for fabricating mechanically robust superamphiphobic coatings on aluminum alloy and zinc substrates using a dual-step process combining sandblasting (SB) and steam treatment (ST), followed by surface energy reduction with fluorinated molecules. This approach creates hierarchical micro/nano structures essential for omniphobic performance. On Al-alloy SB + ST surfaces we measured static contact angles of 162.0° (water), 156.1° (ethylene glycol), and 154.4° (peanut oil), while the corresponding Zn surfaces reached 160.1°, 156.0°, and 152.8°, respectively, with sliding angles below 5° across all tested liquids. The coatings retained high repellency after 50 tape-peeling cycles and 100 cm of sandpaper abrasion under a 500 g load (e.g., ethylene glycol > 140° and peanut oil ≈ 120°). They also showed resistance to water jet impact, excellent self-cleaning, and anti-fogging performance. Compared to conventional hot water treatment or chemical etching, this ST-based method enables faster, cleaner fabrication and significantly enhances mechanical durability making it a promising candidate for large-scale applications in anti-fouling, anti-corrosion, and protective surface technologies.