Abstract
The strong and ductile single-phase body-centered-cubic (BCC) HfNbTaTiZr refractory high-entropy alloy (RHEA) is a potential structural material for high-temperature applications. However, the BCC phase stability in the intermediate temperature range (500–900 °C) needs to be better understood to make this alloy applicable to industry. In the present work, the phase decomposition of the HfNbTaTiZr RHEA is examined at different temperatures (500–1000 °C). Additionally, the formation of BCC Ta-Nb-rich and hexagonal-close-packed (HCP) Hf-Zr-rich precipitates are studied as a function of annealing time at 700 °C using a combination of atom probe tomography, transmission electron microscopy, and X-ray diffraction. We found that these BCC and HCP precipitates have preferred orientations with the BCC matrix.
| Original language | English |
|---|---|
| Pages (from-to) | 50-56 |
| Number of pages | 7 |
| Journal | Scripta Materialia |
| Volume | 158 |
| DOIs | |
| State | Published - Jan 1 2019 |
Funding
We are grateful for the support of the Department of Energy (DOE) Office of Fossil Energy, National Energy Technology Laboratory (NETL) ( DE-FE-0011194 ) and the National Science Foundation ( DMR-1611180 and 1809640 ), with Drs. J. Mullen, V. Cedro, R. Dunst, S. Markovich, G. Shiflet, and D. Farkas as program managers. R. F. and P.K.L. very much appreciate the support from the U.S. Army Office Project (W911NF-13-1-0438) with the program manager, Drs. M. P. Bakas, S. N. Mathaudhu, and D. M. Stepp. S.Y.C. and P.K.L. would like to acknowledge the financial support of the Center for Materials Processing ( CMP ), at The University of Tennessee, with the director of Dr. Claudia J. Rawn. M.C.G. acknowledges the support of the Cross-Cutting Technologies Program at the US DOE NETL under the RES contract of DE-FE0004000. The current research used resources of the National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy Office of Science User Facility operated under Contract No. of DE-AC02-05CH11231. APT was conducted at ORNL's Center for Nanophase Materials Sciences (CNMS), which is a U.S. DOE Office of Science User Facility. The use of the Advanced Photon Source and Center for Nanoscale Materials at ANL, an Office of Science user facility, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. of DE-AC02-06CH11357. J.W.Yeh would like to thank the financial support by the \u201CHigh Entropy Materials Center\u201D from The Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE) and from the Project of MOST 107-3017-F-007-003 by the Ministry of Science and Technology (MOST) in Taiwan. XRD was performed at the Joint Institute for Advanced Materials (JIAM) Diffraction Facility, located at the University of Tennessee, Knoxville. This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ).
Keywords
- Annealing
- High-entropy alloys
- Phase decomposition