Dislocation flow turbulence simultaneously enhances strength and ductility

• 成果类型: Article
• 署名作者: Chen, Yang; Feng, Hui; Li, Jia; Liu, Bin; Jiang, Chao; Liu, Yong; Fang, Qihong; Liaw, Peter K.
• 署名单位: Hunan University; Central South University; University of Tennessee System; University of Tennessee Knoxville
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-15403
• DOI: 10.1073/pnas.2316912121
• 发表日期: 2024-03-26
• 关键词: high-entropy alloys; short-range order

摘要

Multi- principal element alloys (MPEAs) exhibit outstanding strength attributed to the complex dislocation dynamics as compared to conventional alloys. Here, we develop an atomic- lattice- distortion- dependent discrete dislocation dynamics framework consisted of random field theory and phenomenological dislocation model to investigate the fundamental deformation mechanism underlying massive dislocation motions in body- centered cubic MPEA. Amazingly, the turbulence of dislocation speed is identified in light of strong heterogeneous lattice strain field caused by short- range ordering. Importantly, the vortex from dislocation flow turbulence not only acts as an effective source to initiate dislocation multiplication but also induces the strong local pinning trap to block dislocation movement, thus breaking the strength- ductility trade- off.