Thermal and Cold Spray High-Entropy Alloy Coatings

High-entropy alloys (HEAs) are a novel category of materials characterized by distinctive microstructures and remarkable properties that render them highly advantageous for advanced coating applications. The utilization of HEAs as feedstock for thermal spray coating methods has garnered considerable attention owing to their exceptional mechanical, thermal, and corrosion-resistant characteristics in both the bulk and coated states. Over the last decade, HEA-based coatings, comprising metallic, ceramic, and composite types, have rapidly advanced, garnering interest owing to their exceptional performance under challenging conditions. This chapter presents research advances in HEA coatings deposited using thermal spray coating techniques, with selected examples of plasma spray, high-velocity oxygen fuel spray, and cold spray HEA coatings. Furthermore, this chapter discusses selected studies on the microstructure, phase composition, microhardness, and corrosion resistance of HEA coatings, emphasizing their benefits for engineering and industrial applications.