Abstract
Refractory high-entropy alloys (RHEAs) show promising applications at high temperatures. However, achieving high strengths at elevated temperatures above 1173K is still challenging due to heat softening. Using intrinsic material characteristics as the alloy-design principles, a single-phase body-centered-cubic (BCC) CrMoNbV RHEA with high-temperature strengths (beyond 1000 MPa at 1273 K) is designed, superior to other reported RHEAs as well as conventional superalloys. The origin of the high-temperature strength is revealed by in situ neutron scattering, transmission-electron microscopy, and first-principles calculations. The CrMoNbV's elevated-temperature strength retention up to 1273 K arises from its large atomic-size and elastic-modulus mismatches, the insensitive temperature dependence of elastic constants, and the dominance of non-screw character dislocations caused by the strong solute pinning, which makes the solid-solution strengthening pronounced. The alloy-design principles and the insights in this study pave the way to design RHEAs with outstanding high-temperature strength.
| Original language | English |
|---|---|
| Article number | 2102401 |
| Journal | Advanced Materials |
| Volume | 33 |
| Issue number | 48 |
| DOIs | |
| State | Published - Dec 2 2021 |
Funding
P.K.L. appreciates the support from (1) the National Science Foundation (DMR‐1611180 and 1809640) with program directors, Drs. J. Yang, G. Shiflet, and D. Farkas and (2) the US Army Research Office (W911NF‐13‐1‐0438 and W911NF‐19‐2‐0049) with program managers, Drs. M. P. Bakas, S. N. Mathaudhu, and D. M. Stepp. First‐principles simulation and elasticity modeling by M.W. was supported by the Department of Energy grant DE‐SC0014506 and by the National Science Foundation through an XSEDE grant of DMR160149 at the Pittsburgh Supercomputer Center. M.C.G. acknowledges the support of the Cross‐Cutting Technologies Program at the US DOE National Energy Technology Laboratory (NETL). R.F. thanks for the support from the Materials and Engineering Initiative at the Spallation Neutron Source (SNS) and High Flux Isotope Reactor (HFIR), Oak Ridge National Laboratory (ORNL). This research used resources at the SNS, a U.S. Department of Energy (DOE) Office of Science User Facility operated by the ORNL. Synchrotron diffraction was conducted at the Advanced Photon Source (APS), a U.S. DOE Office of Science User Facility operated for the DOE Office of Science by the Argonne National Laboratory under the Contract No. of DE‐AC02‐06CH11357. APT was conducted at the ORNL's Center for Nanophase Materials Sciences (CNMS), which is a U.S. DOE Office of Science User Facility. The authors thank Drs. M. Frost and D. Yu at SNS for their technical support. The authors would like to thank James Burns for his assistance in performing APT sample preparation and running the APT experiments. The authors appreciate the comments from Prof. W. Curtin at École Polytechnique Fédérale de Lausanne. The authors also thank the discussions on the TEM analysis with Prof. J. M. Zuo and Dr. H. W. Hsiao at the University of Illinois at Urbana‐Champaign. 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, worldwide 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 ). P.K.L. appreciates the support from (1) the National Science Foundation (DMR-1611180 and 1809640) with program directors, Drs. J. Yang, G. Shiflet, and D. Farkas and (2) the US Army Research Office (W911NF-13-1-0438 and W911NF-19-2-0049) with program managers, Drs. M. P. Bakas, S. N. Mathaudhu, and D. M. Stepp. First-principles simulation and elasticity modeling by M.W. was supported by the Department of Energy grant DE-SC0014506 and by the National Science Foundation through an XSEDE grant of DMR160149 at the Pittsburgh Supercomputer Center. M.C.G. acknowledges the support of the Cross-Cutting Technologies Program at the US DOE National Energy Technology Laboratory (NETL). R.F. thanks for the support from the Materials and Engineering Initiative at the Spallation Neutron Source (SNS) and High Flux Isotope Reactor (HFIR), Oak Ridge National Laboratory (ORNL). This research used resources at the SNS, a U.S. Department of Energy (DOE) Office of Science User Facility operated by the ORNL. Synchrotron diffraction was conducted at the Advanced Photon Source (APS), a U.S. DOE Office of Science User Facility operated for the DOE Office of Science by the Argonne National Laboratory under the Contract No. of DE-AC02-06CH11357. APT was conducted at the ORNL's Center for Nanophase Materials Sciences (CNMS), which is a U.S. DOE Office of Science User Facility. The authors thank Drs. M. Frost and D. Yu at SNS for their technical support. The authors would like to thank James Burns for his assistance in performing APT sample preparation and running the APT experiments. The authors appreciate the comments from Prof. W. Curtin at École Polytechnique Fédérale de Lausanne. The authors also thank the discussions on the TEM analysis with Prof. J. M. Zuo and Dr. H. W. Hsiao at the University of Illinois at Urbana-Champaign. 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, worldwide 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
- alloy design
- high-temperature strength
- neutron scattering
- phase stability
- refractory high-entropy alloy