Corrosion-Resistant Coating Based on High-Entropy Alloys

Metal corrosion leads to serious resource waste and economic losses, and in severe cases, it can result in catastrophic safety incidents. As a result, proper coatings are often employed to separate metal alloys from the ambient environment and thus prevent or at least slow down corrosion. Among various materials, high-entropy alloy coatings (HEA coating) have recently received a lot of attention due to their unique entropy-stabilized structure, superior physical and chemical properties, and often excellent corrosion resistance. To address the recent developments and remaining issues in HEA coatings, this paper reviews the primary fabrication methods and various elemental compositions in HEA coatings and highlights their effects on corrosion resistance properties. It is found that FeCoCrNi-based and refractory high-entropy alloy coatings prepared by the laser/plasma cladding method typically show better corrosion resistance. It also briefly discusses the future directions toward high-performing corrosion-resistant coatings based on HEA design.