中国物理B ›› 2022, Vol. 31 ›› Issue (6): 66204-066204.doi: 10.1088/1674-1056/ac4cc6

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Strengthening and softening in gradient nanotwinned FCC metallic multilayers

Yuanyuan Tian(田圆圆), Gangjie Luo(罗港杰), Qihong Fang(方棋洪),Jia Li(李甲), and Jing Peng(彭静)   

  1. State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha 410082, China
  • 收稿日期:2021-10-09 修回日期:2021-12-21 接受日期:2022-01-19 出版日期:2022-05-17 发布日期:2022-05-17
  • 通讯作者: Qihong Fang, Jia Li E-mail:fangqh1327@hnu.edu.cn;lijia123@hnu.edu.cn
  • 基金资助:
    The authors would like to deeply appreciate the support from the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (Grant Nos. 51621004, 11572118, 51871092, and 11772122) and the National Key Research and Development Program of China (Grant No. 2016YFB0700300).

Strengthening and softening in gradient nanotwinned FCC metallic multilayers

Yuanyuan Tian(田圆圆), Gangjie Luo(罗港杰), Qihong Fang(方棋洪),Jia Li(李甲), and Jing Peng(彭静)   

  1. State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha 410082, China
  • Received:2021-10-09 Revised:2021-12-21 Accepted:2022-01-19 Online:2022-05-17 Published:2022-05-17
  • Contact: Qihong Fang, Jia Li E-mail:fangqh1327@hnu.edu.cn;lijia123@hnu.edu.cn
  • Supported by:
    The authors would like to deeply appreciate the support from the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (Grant Nos. 51621004, 11572118, 51871092, and 11772122) and the National Key Research and Development Program of China (Grant No. 2016YFB0700300).

摘要: Plastic-deformation behaviors of gradient nanotwinned (GNT) metallic multilayers are investigated in nanoscale via molecular dynamics simulation. The evolution law of deformation behaviors of GNT metallic multilayers with different stacking fault energies (SFEs) during nanoindentation is revealed. The deformation behavior transforms from the dislocation dynamics to the twinning/detwinning in the GNT Ag, Cu, to Al with SFE increasing. In addition, it is found that the GNT Ag and GNT Cu strengthen in the case of a larger twin gradient based on more significant twin boundary (TB) strengthening and dislocation strengthening, while the GNT Al softens due to more TB migration and dislocation nucleation from TB at a larger twin gradient. The softening mechanism is further analyzed theoretically. These results not only provide an atomic insight into the plastic-deformation behaviors of certain GNT metallic multilayers with different SFEs, but also give a guideline to design the GNT metallic multilayers with required mechanical properties.

关键词: plastic deformation, gradient nanotwinned metallic multilayers, nanoindentation, molecular dynamics simulation

Abstract: Plastic-deformation behaviors of gradient nanotwinned (GNT) metallic multilayers are investigated in nanoscale via molecular dynamics simulation. The evolution law of deformation behaviors of GNT metallic multilayers with different stacking fault energies (SFEs) during nanoindentation is revealed. The deformation behavior transforms from the dislocation dynamics to the twinning/detwinning in the GNT Ag, Cu, to Al with SFE increasing. In addition, it is found that the GNT Ag and GNT Cu strengthen in the case of a larger twin gradient based on more significant twin boundary (TB) strengthening and dislocation strengthening, while the GNT Al softens due to more TB migration and dislocation nucleation from TB at a larger twin gradient. The softening mechanism is further analyzed theoretically. These results not only provide an atomic insight into the plastic-deformation behaviors of certain GNT metallic multilayers with different SFEs, but also give a guideline to design the GNT metallic multilayers with required mechanical properties.

Key words: plastic deformation, gradient nanotwinned metallic multilayers, nanoindentation, molecular dynamics simulation

中图分类号:  (Deformation and plasticity)

  • 62.20.F-
61.72.Mm (Grain and twin boundaries) 68.35.bd (Metals and alloys) 02.70.Ns (Molecular dynamics and particle methods)