High-entropy alloys for complex marine corrosion: compositional design, structural engineering, and processing strategies

High-entropy alloys (HEAs) represent a paradigm shift in corrosion-resistant material design for marine applications. This review systematically examines the corrosion behavior of HEAs through an integrated analysis of compositional design, microstructural engineering, and processing strategies. The analysis demonstrates how individual elements and their synergistic interactions govern passive film quality and phase characteristics to control corrosion. Furthermore, specific microstructural features such as amorphous, nanocrystalline and eutectic structures significantly enhance corrosion resistance through their intrinsic properties, grain refinement, and optimized interface control. Moreover, advanced processing techniques enable this performance by precisely regulating elemental homogeneity and microstructural evolution. Finally, the review outlines key future research directions, thereby providing both a fundamental understanding and practical guidelines for designing high-performance HEAs for severe marine environments.