Self-adaptive dislocation morphing ductilizes a refractory high-entropy alloy across an ultrawide temperature spectrum
Abstract
Metals usually fracture catastrophically at cryogenic temperatures and soften rapidly at high temperatures. This dilemma arises from the incompatibility of strengthening mechanisms across vast temperature regimes. Here, this work unveils a self-adaptive dislocation morphing mechanism in a model NbTaTi-based refractory high-entropy alloy (RHEA) that enables exceptional strength and ductility from 4 K to 1673 K. At cryogenic temperatures, dislocation kinking coupled with deformation twinning suppresses the ductile-to-brittle transition. At ambient conditions, the sequential activation of edge and screw dislocations sustains work hardening. At elevated temperatures, enhanced dislocation interactions generate jogs, multijunctions, and helical dislocations, promoting superplasticity up to 250%. This intrinsic, temperature-responsive evolution of dislocation modes offers a defect engineering strategy for designing RHEAs capable of enduring extreme environments.
Article Details
Journal Info
Proceedings of the National Academy of Sciences
National Academy of Sciences
Authors (14)
Xichen Zhou
Department of Chemistry
Qianyong Zhu
Key Laboratory of High-temperature Structural Materials and Coating Technology (Ministry of Industry and Information Technology), School of Materials Science and Engineering, Beihang University
Hongliang Dong
Center for High Pressure Science and Technology Advanced Research
Xiao Liang
Department of Chemistry
Qihan Jia
Key Laboratory of High-temperature Structural Materials and Coating Technology (Ministry of Industry and Information Technology), School of Materials Science and Engineering, Beihang University
Cheng Zhang
Jian He
Department of Chemistry
Wenting He
Key Laboratory of High-temperature Structural Materials and Coating Technology (Ministry of Industry and Information Technology), School of Materials Science and Engineering, Beihang University
Yuye Wu
Key Laboratory of High-temperature Structural Materials and Coating Technology (Ministry of Industry and Information Technology), School of Materials Science and Engineering, Beihang University
Yi Ru
Key Laboratory of High-temperature Structural Materials and Coating Technology (Ministry of Industry and Information Technology), School of Materials Science and Engineering, Beihang University
Bin Chen
Robert O. Ritchie
Hongbo Guo
Key Laboratory of High-temperature Structural Materials and Coating Technology (Ministry of Industry and Information Technology), School of Materials Science and Engineering, Beihang University
Shiteng Zhao
Key Laboratory of High-temperature Structural Materials and Coating Technology (Ministry of Industry and Information Technology), School of Materials Science and Engineering, Beihang University