Strong, ductile, and hierarchical hetero-lamellar-structured alloys through microstructural inheritance and refinement
Abstract
The strength−ductility trade-off exists ubiquitously, especially in brittle intermetallic-containing multiple principal element alloys (MPEAs), where the intermetallic phases often induce premature failure leading to severe ductility reduction. Hierarchical heterogeneities represent a promising microstructural solution to achieve simultaneous strength−ductility enhancement. However, it remains fundamentally challenging to tailor hierarchical heterostructures using conventional methods, which often rely on costly and time-consuming processing. Here, we report a multiscale microstructural inheritance and refinement strategy to process “structural hierarchy precursors” in as-cast heterogeneous Al 0.7 CoCrFeNi MPEAs, which lead directly to a hierarchical hetero-lamellar structure (HLS) after simple rolling and annealing. Interestingly, it takes only 10 min of annealing time, two orders of magnitude less than that required to render the state-of-the-art properties during conventional processing of Al 0.7 CoCrFeNi, for us to achieve record-high strength−ductility combinations via the hierarchical HLS design that sequentially stimulates multiple unusual deformation and reinforcement mechanisms. In particular, the HLS-enabled high hetero-deformation-induced (HDI) internal stress triggers profuse <111>-type dislocations on over five independent slip systems in the supposedly brittle intermetallic phase and activates extensive stacking faults (SFs) and nanotwinning in the adjoining soft phase with a rather high SF energy. These unexpected, dynamically reinforcing hetero-deformation mechanisms across multiple length scales facilitate high sustained HDI strain hardening, along with a salient microcrack-mediated extrinsic ductilization effect, suggesting that the proposed microstructural inheritance and refinement strategy provides an efficient, fast, and low-cost approach to overcome the strength−ductility trade-off in a broad range of structural materials.
Article Details
Journal Info
Proceedings of the National Academy of Sciences
National Academy of Sciences
Authors (26)
Peijian Shi
State Key Laboratory of Advanced Special Steel, Shanghai Key Laboratory of Advanced Ferromletallurgy, School of Materials Science and Engineering, Shanghai University
Yi Li
Zhi Li
Xin Jiang
Jie Yan
Rui Zhou
Yi Qin
State Key Laboratory of Advanced Special Steel, Shanghai Key Laboratory of Advanced Ferromletallurgy, School of Materials Science and Engineering, Shanghai University
Yifan Lin
State Key Laboratory of Elemento-Organic Chemistry and Frontiers Science Center for New Organic Matter, College of Chemistry
Jingran Huang
State Key Laboratory of Advanced Special Steel, Shanghai Key Laboratory of Advanced Ferromletallurgy, School of Materials Science and Engineering, Shanghai University
Bodong Tan
State Key Laboratory of Advanced Special Steel, Shanghai Key Laboratory of Advanced Ferromletallurgy, School of Materials Science and Engineering, Shanghai University
Yinan Wang
Department of Information and Computing Sciences, School of Mathematical Science, Peking University
Tongqi Wen
Department of Mechanical Engineering, The University of Hong Kong
Beilin Ye
Department of Mechanical Engineering, The University of Hong Kong
Chunyan Ling
Department of Advanced Design and Systems Engineering, City University of Hong Kong
Junhua Luan
Department of Materials Science and Engineering, Hong Kong Institute for Advanced Study, City University of Hong Kong
Zhe Shen
Department of Neurobiology, School of Biological Sciences, University of California
Biao Ding
State Key Laboratory of Advanced Special Steel, Shanghai Key Laboratory of Advanced Ferromletallurgy, School of Materials Science and Engineering, Shanghai University
Qiang Li
Tianxiang Zheng
College of Science
Weili Ren
State Key Laboratory of Advanced Special Steel, Shanghai Key Laboratory of Advanced Ferromletallurgy, School of Materials Science and Engineering, Shanghai University
Tianlong Zhang
Department of Mechanical and Aerospace Engineering
Yang Ren
Yunbo Zhong
State Key Laboratory of Advanced Special Steel, Shanghai Key Laboratory of Advanced Ferromletallurgy, School of Materials Science and Engineering, Shanghai University
C. T. Liu
Department of Materials Science and Engineering, Hong Kong Institute for Advanced Study, City University of Hong Kong
Huajian Gao
Yuntian Zhu
Department of Materials Science and Engineering, Hong Kong Institute for Advanced Study, City University of Hong Kong