Abstract
Severe distortion is one of the four core effects in single-phase high-entropy alloys (HEAs) and contributes significantly to the yield strength. However, the connection between the atomic-scale lattice distortion and macro-scale mechanical properties through experimental verification has yet to be fully achieved, owing to two critical challenges: 1) the difficulty in the development of homogeneous single-phase solid-solution HEAs and 2) the ambiguity in describing the lattice distortion and related measurements and calculations. A single-phase body-centered-cubic (BCC) refractory HEA, NbTaTiVZr, using thermodynamic modeling coupled with experimental verifications, is developed. Compared to the previously developed single-phase NbTaTiV HEA, the NbTaTiVZr HEA shows a higher yield strength and comparable plasticity. The increase in yield strength is systematically and quantitatively studied in terms of lattice distortion using a theoretical model, first-principles calculations, synchrotron X-ray/neutron diffraction, atom-probe tomography, and scanning transmission electron microscopy techniques. These results demonstrate that severe lattice distortion is a core factor for developing high strengths in refractory HEAs.
| Original language | English |
|---|---|
| Article number | 2004029 |
| Journal | Advanced Materials |
| Volume | 32 |
| Issue number | 49 |
| DOIs | |
| State | Published - Dec 10 2020 |
Funding
The authors very much appreciate the support from the U.S. Army Office Project (W911NF‐13‐1‐0438 and W911NF‐19‐2‐0049) with the program managers, Drs. Michael P. Bakas, David M. Stepp, and Suveen Mathaudhu. P.K.L. also thanks the support from the National Science Foundation (DMR‐1611180 and 1809640) with the program directors, Drs. Judith Yang, Gary Shiflet, and Diana Farkas. The CALPHAD modeling work was carried out to support the US Department of Energy's Fossil Energy Cross‐Cutting Technologies Program at the National Energy Technology Laboratory (NETL) under the RSS contract of 89243318CFE000003. Atom probe tomography (APT) was conducted at Oak Ridge National Laboratory's (ORNL) Center for Nanophase Materials Sciences (CNMS), which is a U.S. DOE Office of Science User Facility (J.D.P.). The authors would like to thank James Burns for performing APT sample preparation and running the APT experiments. A portion of research at the ORNL's Spallation Neutron Source was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. DOE. The calculations were performed, using the computational resources of the National Energy Research Scientific Computing Center, which is supported under the Office of Science of the U.S. Department of Energy under Contract No DE‐AC02‐05CH11231. W.C. acknowledges the support from the National Science Foundation under the CAREER award DMR‐1945380. The present research used resources of the National Energy Research Scientific Computing Center (NERSC), a U.S. DOE Office of Science User Facility operated under Contract No. DE‐AC02‐05CH11231. The present work employed the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by the National Science Foundation grant number ACI‐1548562. Y.C. and Y.C.C. thank the funding from the Ministry of Science and Technology (MOST) of Taiwan under Grant No. MOST‐109‐2636‐M‐009‐002, the core facility support at the National Chiao Tung University (NCTU) from MOST. Y.C.C. thanks the partial support from the “Center for the Semiconductor Technology Research” from The Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE) in Taiwan, which is supported in part by the Ministry of Science and Technology, Taiwan, under Grant MOST 109‐2634‐F‐009‐029. The present work was supported by the Basic Research Laboratory Program through the Ministry of Education of the Republic of Korea (2019R1A4A1026125) and the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. 2020R1C1C1005553). This research used resources of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE‐AC02‐06CH11357. The authors would like to thank Kyungjun Lee for assistance with the illustration of figures. The present work was funded by the Department of Energy, National Energy Technology Laboratory, an agency of the United States Government, through a support contract with the Leidos Research Support Team (LRST). Neither the United States Government nor any agency thereof, nor any of their employees, nor LRST, nor any of their employees, makes any warranty, expressed, or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.
Keywords
- NbTaTiVZr
- alloy-design strategies
- lattice distortion
- microstructure
- refractory high-entropy alloys
- yield strength