Thermal Barrier High-Entropy Alloy Coatings

Thermal barrier coatings (TBCs) are critical in protecting components exposed to extreme temperatures, mechanical stresses, and corrosive environments, particularly in aerospace, power generation, and high-temperature industrial applications. High-entropy alloys (HEAs), with their unique multi-element compositions and remarkable properties, are emerging as transformative materials for next-generation TBCs. This chapter explores the advancements in HEA-based TBCs, focusing on their exceptional thermal stability, oxidation and corrosion resistance, mechanical robustness, and adaptability for diverse applications. Key aspects of HEA design for TBCs are discussed, including criteria for element selection, microstructural optimization, and compatibility with conventional substrates and topcoats. Innovative synthesis and fabrication techniques, such as physical vapor deposition, laser cladding, and thermal spraying, are examined for their role in achieving high-quality, durable coatings. Additionally, emerging research areas such as multi-functional and hybrid HEA TBC systems, bio-inspired designs, and self-healing mechanisms are explored as potential solutions to current limitations. Sustainability and environmental considerations, including material availability, energy-efficient processes, and recyclability, are highlighted to ensure the responsible development of HEA-based coatings. By integrating experimental findings, computational modeling, and machine learning, this chapter presents a comprehensive overview of HEA-based TBCs as a breakthrough technology that can redefine high-temperature coating performance, enabling enhanced efficiency, durability, and sustainability across critical industries.