Excitements and Challenges in High Entropy Alloy Research

Abstract:

HEAs are a new class of multi-component equiatomic (or near equiatomic) alloys, which form simple solid solutions due to their high configurational entropy. In spite of the excitement that the field has generated and the large number of studies being carried out by many groups, there are many challenges in this field both in terms of fundamental understanding and processing. It is important to note that all multi-component equiatomic alloys do not lead to the formation of single phase solid solution in a number cases. Some of the HEAs have shown the formation of intermetallic phases and in some cases phase separation of certain elements with high positive enthalpy of mixing with other elements has been observed. Prediction of the phase formation in HEAs is a major challenge in this field. Understanding the stability the phases is also a major challenge due to possible sluggish diffusivity in these alloys making it difficult to understand whether the phases obtained are thermodynamically stable or kinetically stabilised. Processing of the alloys in large quantities in various forms for useful applications also remains a major challenge. The present paper brings out some of these issues based on the ongoing work in the research group of the speaker.

About the Speaker

Dr. B.S. Murty has obtained his ME (1988) and PhD (1992) from IISc, Bangalore. He was a faculty member at IIT Kharagpur during 1992-2004 before joining IIT Madras in 2004. He is also an Adjunct Professor at Ryerson University, Toronto, Canada and an Associate faculty of School of Engineering, University of British Columbia, Canada.

His research interests are in the areas of nano materials and other advanced materials. He has authored about 380 journal publications and filed 18 patents and published three books. He has supervised 35 PhDs and 15 PhDs are ongoing. He has handled over 50 sponsored research projects. He is a recipient of a number of awards including Honorary Doctorate from Deakin University, Australia (2017), Life time Achievement Award of IIT Madras (2016), Distinguished Alumnus Award of VNIT (2010), Shanti Swarup Bhatnagar Award (2007), Metallurgist of the Year Award (2004). His is a Fellow of The World Academy of Sciences (2018), Asia Pacific Academy of Materials (2013), ASM International (2010) and all Indian Science and Engineering Academies.