Comprehensive review on high entropy alloy-based coating

High-entropy alloys (HEAs) based coatings have great potential in distinct sectors owing to their attractive properties. These alloys offered high specific strength, superior mechanical properties, superconductivity, super-paramagnetism, high fracture toughness at cryogenic temperatures, etc. These alloys contain multiple principal elements, with the possible number of high entropy alloy compositions extending significantly more than conventional alloys. Hence, the use of HEAs as feedstock material for coating processes has increased, especially for surface protection of various materials in distinct environments. Therefore this manuscript aims to provide an overview of HEA coatings, types, fabrication methods, post-processing of HEAs coatings and their diverse applications. Then, the mechanical and tribological properties of the HEAs-based coating developed by various researchers are summarized. In addition, this paper discusses the properties of HEAs and compares HEAs with traditional alloys. Finally, this paper presents the recent advances in HEAs for 3D printing, including research lapses, prospects and future opportunities.