中国物理B ›› 2024, Vol. 33 ›› Issue (1): 16202-16202.doi: 10.1088/1674-1056/acfc37

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Atomistic evaluation of tension—compression asymmetry in nanoscale body-centered-cubic AlCrFeCoNi high-entropy alloy

Runlong Xing(邢润龙) and Xuepeng Liu(刘雪鹏)   

  1. Anhui Province Key Laboratory of Aerospace Structural Parts Forming Technology and Equipment, Institute of Industry and Equipment Technology, Hefei University of Technology, Hefei 230009, China
  • 收稿日期:2023-07-15 修回日期:2023-09-20 接受日期:2023-09-22 出版日期:2023-12-13 发布日期:2024-01-03
  • 通讯作者: Xuepeng Liu E-mail:liuxuepeng@hfut.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 12272118) and the National Key Research and Development Program of China (Grant No. 2022YFE03030003).

Atomistic evaluation of tension—compression asymmetry in nanoscale body-centered-cubic AlCrFeCoNi high-entropy alloy

Runlong Xing(邢润龙) and Xuepeng Liu(刘雪鹏)   

  1. Anhui Province Key Laboratory of Aerospace Structural Parts Forming Technology and Equipment, Institute of Industry and Equipment Technology, Hefei University of Technology, Hefei 230009, China
  • Received:2023-07-15 Revised:2023-09-20 Accepted:2023-09-22 Online:2023-12-13 Published:2024-01-03
  • Contact: Xuepeng Liu E-mail:liuxuepeng@hfut.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 12272118) and the National Key Research and Development Program of China (Grant No. 2022YFE03030003).

摘要: The tension and compression of face-centered-cubic high-entropy alloy (HEA) nanowires are significantly asymmetric, but the tension--compression asymmetry in nanoscale body-centered-cubic (BCC) HEAs is still unclear. In this study, the tension--compression asymmetry of the BCC AlCrFeCoNi HEA nanowire is investigated using molecular dynamics simulations. The results show a significant asymmetry in both the yield and flow stresses, with BCC HEA nanowire stronger under compression than under tension. The strength asymmetry originates from the completely different deformation mechanisms in tension and compression. In compression, atomic amorphization dominates plastic deformation and contributes to the strengthening, while in tension, deformation twinning prevails and weakens the HEA nanowire. The tension--compression asymmetry exhibits a clear trend of increasing with the increasing nanowire cross-sectional edge length and decreasing temperature. In particular, the compressive strengths along the [001] and [111] crystallographic orientations are stronger than the tensile counterparts, while the [110] crystallographic orientation shows the exactly opposite trend. The dependences of tension--compression asymmetry on the cross-sectional edge length, crystallographic orientation, and temperature are explained in terms of the deformation behavior of HEA nanowire as well as its variations caused by the change in these influential factors. These findings may deepen our understanding of the tension--compression asymmetry of the BCC HEA nanowires.

关键词: high-entropy alloys, body-centered-cubic, nanowire, tension--compression asymmetry, atomistic simulations

Abstract: The tension and compression of face-centered-cubic high-entropy alloy (HEA) nanowires are significantly asymmetric, but the tension--compression asymmetry in nanoscale body-centered-cubic (BCC) HEAs is still unclear. In this study, the tension--compression asymmetry of the BCC AlCrFeCoNi HEA nanowire is investigated using molecular dynamics simulations. The results show a significant asymmetry in both the yield and flow stresses, with BCC HEA nanowire stronger under compression than under tension. The strength asymmetry originates from the completely different deformation mechanisms in tension and compression. In compression, atomic amorphization dominates plastic deformation and contributes to the strengthening, while in tension, deformation twinning prevails and weakens the HEA nanowire. The tension--compression asymmetry exhibits a clear trend of increasing with the increasing nanowire cross-sectional edge length and decreasing temperature. In particular, the compressive strengths along the [001] and [111] crystallographic orientations are stronger than the tensile counterparts, while the [110] crystallographic orientation shows the exactly opposite trend. The dependences of tension--compression asymmetry on the cross-sectional edge length, crystallographic orientation, and temperature are explained in terms of the deformation behavior of HEA nanowire as well as its variations caused by the change in these influential factors. These findings may deepen our understanding of the tension--compression asymmetry of the BCC HEA nanowires.

Key words: high-entropy alloys, body-centered-cubic, nanowire, tension--compression asymmetry, atomistic simulations

中图分类号:  (Mechanical properties of nanoscale systems)

  • 62.25.-g
62.23.Hj (Nanowires) 61.66.Dk (Alloys ) 02.70.Ns (Molecular dynamics and particle methods)