High Entropy Alloys

This book provides a complete review of the current state of the art in the field of high entropy alloys (HEA). The conventional approach to alloy design is to select one principal element and add elements to it in minor quantities in order to improve the properties. In 2004, Professor J.W. Yeh and his group first reported a new approach to alloy design, which involved mixing elements in equiatomic or near-equiatomic proportions, to form multi-component alloys with no single principal element. These alloys are expected to have high configurational entropy and hence were termed as "high entropy alloys."
HEAs have a broad range of structures and properties, and may find applications in structural, electrical, magnetic, high-temperature, wear-resistant, corrosion-resistant, and oxidation-resistant components. Due to their unique properties, high entropy alloys have attracted considerable attention from both academics and technologists. This book presents the fundamental knowledge present in the field, the spectrum of various alloy systems and their characteristics studied to date, current key focus areas, and the future scope of the field in terms of research and technological applications.

• Encompasses the synthesis and phase formation of high entropy alloys
• Covers design of HEAs based on thermodynamic criteria
• Discusses the structural and functional properties of HEAs
• Provides a comparison of HEAs with other multicomponent systems like intermetallics and bulk metallic glasses

Dr. B.S. Murty is a Professor, Department of Metallurgical and Materials Engineering, IIT Madras, Chennai, India. He has pioneered the synthesis of nanocrystalline materials by mechanical alloying route. His other important contributions are in the field of bulk metallic glasses and in-situ composites. He has co-authrored a Text Book on Nanoscience and Nanotechnology. He has also made significant contributions to the field of high-entropy alloys.

Jien-Wei Yeh is a pioneering materials scientist whose expertise spans aluminum and magnesium alloys, metal matrix composites, metallic glasses, coatings, reciprocating extrusion, and high-entropy materials (HEMs). Since 1995, he has led groundbreaking research that redefined alloy design by proposing material compositions beyond traditional boundaries, unlocking vast compositional possibilities across the Periodic Table. He coined and defined “high-entropy alloys (HEAs),” established their four core effects, and laid the theoretical foundation for this rapidly expanding field. His work further extended high-entropy concepts to ceramics, polymers, and composites, catalyzing global development of high-entropy materials. He has been elected as an academician in Academia Sinica, and has received many prestigious awards, including the Executive Yuan Award for Outstanding Science and Technology Contribution (2021) and the Taiwan Presidential Scientific Award (2025). In Stanford’s global rankings in scientific influence, he ranked second worldwide in Materials.

Dr. Srinivasa Ranganathan is NASI Platinum Jubilee Fellow at the Indian Institute of Science, Bangalore. His academic career as an educator and researcher in metallurgy for the past four decades at the Banaras Hindu University and the Indian Institute of Science has been stellar. He has made significant contributions to our understanding of the structure of interfaces, quasicrystals, bulk metallic glasses and nanostructured materials. He has co-authored a book on New Geometries for New Materials.