Composite High-Entropy Alloy Coatings

This chapter discusses the characteristics and potential applications of composite high-entropy alloys (CHEAs) coatings, which integrate the distinctive features of high-entropy alloys (HEAs) with reinforcing materials to improve functionality across various industrial applications. HEAs, which consist of five or more primary elements, are known for their exceptional mechanical, thermal, and corrosion-resistant properties. By incorporating reinforcements such as ceramics, metals, or polymers into HEAs, CHEAs are formed, exhibiting enhanced hardness, toughness, and overall durability. The chapter elucidates the mechanisms responsible for these improvements, including load transfer phenomena and grain boundary fortification. Additionally, the study explores several coating methodologies, including plasma transferred arc cladding, thermal spraying, and electroplating, which enable the application of CHEAs onto substrates for surface enhancement. These coatings are particularly advantageous in sectors such as aerospace, automotive, and biomedical engineering, owing to their capacity to endure extreme conditions and extend the lifespan of components. However, the chapter also identifies several challenges associated with the production and implementation of CHEA coatings, such as elevated costs, processing intricacies, and microstructural stability issues. Future research avenues are proposed, focusing on the optimization of compositions and the exploration of interactions among the constituent elements to maximize the potential of CHEAs. This chapter aspires to contribute to the fields of materials science and engineering by offering insights into the economic advantages, industrial requirements, and strategies for performance enhancement of CHEAs coatings, thereby addressing the current limitations in their application.