Abstract
Similar to conventional materials, most multicomponent high-entropy alloys (HEAs) lose ductility as they gain strength. In this study, we controllably introduced gradient nanoscaled dislocation cell structures in a stable single-phase HEA with face-centered cubic structure, thus resulting in enhanced strength without apparent loss of ductility. Upon application of strain, the sample-level structural gradient induces progressive formation of a high density of tiny stacking faults (SFs) and twins, nucleating from abundant low-angle dislocation cells. Furthermore, the SF-induced plasticity and the resultant refined structures, coupled with intensively accumulated dislocations, contribute to plasticity, increased strength, and work hardening. These findings offer a promising paradigm for tailoring properties with gradient dislocation cells at the nanoscale and advance our fundamental understanding of the intrinsic deformation behavior of HEAs.
| Original language | English |
|---|---|
| Pages (from-to) | 984-989 |
| Number of pages | 6 |
| Journal | Science |
| Volume | 374 |
| Issue number | 6570 |
| DOIs | |
| State | Published - Nov 19 2021 |
Funding
Q.P. and L.L. acknowledge financial support from the National Science Foundation of China (NSFC; grants 51931010, 92163202, 52122104, and 52071321), the Key Research Program of Frontier Science and International partnership program (GJHZ2029), Youth Innovation Promotion Association (2019196), the Chinese Academy of Sciences (CAS), and LiaoNing Revitalization Talents Program (XLYC1802026). P.K.L. appreciates support from the National Science Foundation (DMR-1611180 and 1809640) and the US Army Research Office (W911NF-13-1-0438 and W911NF-19-2-0049). This study used resources at the Spallation Neutron Source (SNS), a US Department of Energy (DOE) Office of Science User Facility operated by the Oak Ridge National Laboratory (ORNL). Synchrotron diffraction was conducted at the Advanced Photon Source (APS), a US DOE Office of Science User Facility operated for the DOE Office of Science by the Argonne National Laboratory under contract DE-AC02-06CH11357. APT was conducted at ORNL’s Center for Nanophase Materials Sciences (CNMS), which is a US DOE Office of Science User Facility. R.F. is grateful for support from Material Engineering Initiative (MEI) at SNS, ORNL.