The Corrosion‐Resistance of High‐Entropy Alloy and High‐Entropy Alloy Coatings: A Review

ABSTRACT Corrosion, which accounts for over 3% of annual global economic losses, underscores an urgent and growing demand for high‐performance anticorrosion materials. High‐entropy alloy (HEA), marking a paradigm shift beyond conventional alloy design, exhibits the distinctive microstructural characteristics—such as multi‐principal‐element solid solutions and inherent atomic‐scale chemical disorder. These features contribute to the exceptional corrosion resistance, positioning HEA as a promising candidate for advanced protective materials. However, the widespread adoption of bulk HEA in large‐scale or complex industrial applications remains hindered by prohibitively high manufacturing costs, dimensional limitations, and difficulties in processing. In response, the development of HEA coatings—guided by the core HEA principles and enhanced through surface engineering—has emerged as a pivotal strategy to overcome these barriers. Such HEA coatings preserve the simplified phase structures and superior functional properties of their bulk counterparts, while enabling the broader applicability and better economic feasibility. Recent advances in the novel compositional design and microstructure optimization have further established HEA coatings as a leading‐edge research domain within corrosion protection. This review systematically examines the corrosion mechanisms and performances of both bulk HEA and HEA‐based coatings, identifies key factors governing their corrosion behaviors, and critically discusses the existing gaps in the fundamental understanding. Finally, it outlines future research directions for deciphering corrosion mechanisms and proposes strategic approaches toward designing next‐generation HEA coatings with the enhancing durability and applicability, highlighting the necessity of this comprehensive overview to steer future innovation in the corrosion‐resistant material design.