One-step spraying method to construct superhydrophobic magnesium surface with extraordinary robustness and multi-functions

The robust magnesium surfaces with multi-functions are highly desirable, and the simple and scalable methods to construct such surfaces are urgently indispensable. Herein, we conducted a one-step spraying method to facilely fabricate the robust coating with multi-functions on magnesium alloys. The as-sprayed magnesium alloys surface is superhydrophobic with a static water contact angle (WCA) of 157.0° and a roll-off angle of 6.0°. Such surface has excellent mechanical, chemical and thermal stabilities, even undergoing various physical and chemical damages, including sand impact (10 g min⁻¹, ≥20 min), water impact (2 impacts s⁻¹, ≥ 180 min), abrasion (1.00 kPa, ≥25 cycles), peeling (≥2.15 kPa), high temperature (200°C, ≥24 h), strong acidic/salty/basic media (pH = 1∼13) and organic-solvent immersion (ethanol and n-hexane, ≥24 h), demonstrating brilliant robustness. Notably, the surface displays multi-functions of corrosion protection, anti-fouling and heat insulation, which will undoubtedly promote the much wider applications of magnesium alloys.