Strong, ductile, and hierarchical hetero- lamellar- structured alloys through microstructural inheritance and refinement

• 成果类型: Article
• 署名作者: Shi, Peijian; Li, Yi; Li, Zhi; Jiang, Xin; Yan, Jie; Zhou, Rui; Qin, Yi; Lin, Yifan; Huang, Jingran; Tan, Bodong; Wang, Yinan; Wen, Tongqi; Ye, Beilin; Ling, Chunyan; Luan, Junhua; Shen, Zhe; Ding, Biao; Li, Qiang; Zheng, Tianxiang; Ren, Weili; Zhang, Tianlong; Ren, Yang; Zhong, Yunbo; Liu, C. T.; Gao, Huajian; Zhu, Yuntian
• 署名单位: Shanghai University; City University of Hong Kong; Agency for Science Technology & Research (A*STAR); A*STAR - Institute of High Performance Computing (IHPC); Peking University; University of Hong Kong; City University of Hong Kong; Hong Kong University of Science & Technology; City University of Hong Kong; Tsinghua University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-9937
• DOI: 10.1073/pnas.2409317121
• 发表日期: 2025-01-14
• 关键词: high-entropy alloy; strength; BEHAVIOR

摘要

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 erogeneities represent a promising microstructural solution to achieve simultaneous strength-ductility enhancement. However, it remains fundamentally challenging to hierarchical heterostructures using conventional methods, which often rely on costly time- consuming processing. Here, we report a multiscale microstructural inheritance refinement strategy to process structural hierarchy precursors in as- cast heterogeneous Al0.7CoCrFeNi 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 properties during conventional processing ofAl(0.7)CoCrFeNi, for us to achieve record strength-ductility combinations via the hierarchical HLS design that sequentially ulates multiple unusual deformation and reinforcement mechanisms. In particular, 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 the adjoining soft phase with a rather high SF energy. These unexpected, dynamically reinforcing hetero- deformation mechanisms across multiple length scales facilitate sustained HDI strain hardening, along with a salient microcrack- mediated extrinsic tilization 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.