MSE Colloquium March 3: Daniel Miracle, Refractory complex concentrated alloys (RCCAs) for high temperature applications

Abstract

Refractory complex concentrated alloys (RCCAs), which are also called refractory high-entropy alloys (RHEAs), are extensively explored as candidate materials for high temperature structural applications. They are typically based on three or more refractory elements, have a BCC or B2 matrix, and may have secondary phases in the form of disordered solid solutions and/or intermetallic compounds. Knowledgeable selection of alloying elements allows design of RCCAs with a wide range of densities and mechanical properties. The simultaneous presence of BCC and B2 phases in some of RCCAs may result in a coherent, superalloy-like nano-phase microstructure and unique mechanical properties. This new area of research offers many challenges – a vast number of alloying combinations need to be considered and the resulting microstructures, strengthening and deformation mechanisms, thermo-mechanical processing conditions, mechanical properties and oxidation behaviors need to be explored and understood. This talk introduces the RCCA field, discusses potential applications, reviews current efforts, and develops ideas to guide future efforts.

Bio

Dr. Dan Miracle is a Senior Scientist in the Materials and Manufacturing Directorate of the Air Force Research Laboratory (AFRL). His research has covered nickel-based superalloys and intermetallic compounds; metal matrix composites; advanced aluminum alloys; and boron-modified titanium alloys. His current research explores metallic glasses and high-entropy alloys. Dr. Miracle received a B.S. degree in Materials Science and Engineering from Wright State University, M.S. and Ph.D. degrees in Metallurgical Engineering from The Ohio State University, and an Honorary Doctor of Science from the Institute of Metal Physics, Ukrainian Academy of Sciences. Dr. Miracle is a Fellow of ASM, International; The Minerals, Metals & Materials Society (TMS); AFRL, and is an Honorary Member of the Indian Institute of Metals. Dr. Miracle received the AF Basic Research Award and the Presidential Rank Award. He is author or co-author of over 220 peer-reviewed scientific articles and 7 book chapters, and is co-editor of 6 books. Dr. Miracle has given over 200 plenary, keynote and invited talks.