RECENT ADVANCES IN HIGH ENTROPY ALLOYS FOR HIGH-TEMPERATURE STRUCTURAL APPLICATIONS: A REVIEW

Abstract

The High Entropy Alloys (HEAs), characterized by the presence of multiple principal elements in near-equiatomic proportions, have emerged as a promising class of advanced materials for high-temperature and structural applications. Unlike conventional alloys, HEAs exhibit unique properties such as high strength, excellent thermal stability, superior wear resistance, and enhanced oxidation and corrosion resistance, primarily due to their high configurational entropy, lethargic diffusion, and severe lattice distortion effects. This review presents a comprehensive overview of recent advances in the design, processing, and performance of HEAs, with particular emphasis on their behavior under high-temperature conditions. Key aspects including phase formation, microstructural evolution, mechanical properties, creep resistance, and oxidation behavior are critically discussed. Additionally, various fabrication techniques such as casting, powder metallurgy, and additive manufacturing are examined in relation to their influence on material performance. The challenges associated with HEAs, including cost, scalability, and limited long-term performance data, are also highlighted. Finally, future research directions are proposed, focusing on the development of refractory HEAs, advanced coating systems, and the integration of computational materials science for accelerated alloy design. This review aims to provide valuable insights into the potential of HEAs as next-generation materials for demanding structural and high-temperature applications in aerospace, energy, and automotive sectors.