After a brief introduction to the Institute of Nuclear Energy Safety Technology (INEST), CAS, I would like to introduce our recent work on design of multi-principal element alloys (MPEAs).
MPEAs are regarded as promising candidates for the new generation of nuclear structural materials, due to their high strength and ductility, high radiation-resistance and wide working temperature window etc. However, there is a great challenge for the MPEAs’ composition design: how to effectively and efficiently select the optimal alloy compositions from the vast options. Parametric approaches have been widely used for the phase selection of MPEAs, however, there are still some limitations with the present approaches for the composition design for all kinds of MPEAs. In this presentation, a quick screening approach for the design of solid-solution MPEAs will be presented. A two-parameter model was proposed, which can classify different kinds of alloys, and predict the optimal composition range with solid solution phases. The validity of this approach has been verified by the literature data of various alloys.
Using this approach, three series of the Fe-Mn-Cr-Co-Ni based MPEAs with stable solid solution phases were designed. The microscopic characterization experiments, including TEM, SEM, XRD, EBSD, etc., have been conducted. From the microstructure analysis, it was found that the alloys with compositions Fe36.2Mn13Cr14.9Co22.4Ni13.5 and Fe50Mn12.4Cr13.5 Co15.4Ni8.7 could form stable solid solution of FCC phases with homogeneous element distribution. These results demonstrate that the two-parameter model can provide an effective way for quick screening of MPEA design. It can also be used for other different kinds of MPEAs and facilitate the related research and development.
Mingjie Zheng received her PhD degree from the Chinese University of Hong Kong in 2009, Master degree from Peking University in 2006, and Bachelor degree from Shandong Normal University in 2003. Dr. Zheng had worked as a postdoc in the University of Wisconsin-Madison from 2010 to 2014. After that, Dr. Zheng has been working in the Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, and has been supported by the Hundred Talents Program of the Chinese Academy of Sciences. Her research areas include the mutiscale modeling on the irradiation effects in materials, including irradiation swelling, irradiation hardening/embrittlement, H/He transmutation effects, using the first principle calculation, molecular dynamics simulation, rate theory and phase field methods; as well as the design of high entropy alloys, etc.