Mechanically Durable and Fluorine‐Free Ni–Cr Alloy‐Based Highly Hard Superhydrophobic Coating on Al Alloy

Superhydrophobic coatings, known for their water‐repelling properties, play an important role in corrosion resistance and self‐cleaning applications. This study addresses the pressing need for eco‐friendly and durable fabrication methods for metal surfaces, particularly Al alloys, recognized for their inherent low mechanical properties. The innovative electroplating technique successfully fabricates superhydrophobic coatings on Al alloy surfaces, incorporating a high‐hardness Ni–Cr alloys layer and a low‐surface‐energy stearic acid layer. The resulting coatings exhibit outstanding mechanical durability, corrosion resistance, and self‐cleaning capabilities. With a water contact angle of 165° and a corrosion protection efficiency of 98.6%, these coatings offer a substantial improvement over traditional methods. Moreover, the Leeb hardness of the coated alloy experiences an impressive 83% increase compared to pristine Al alloy. This universally applicable approach opens avenues for developing mechanically robust superhydrophobic coatings on various metallic substrates, with broad implications for engineering applications.