中国物理B ›› 2015, Vol. 24 ›› Issue (8): 88106-088106.doi: 10.1088/1674-1056/24/8/088106

• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇    下一篇

Molecular dynamics simulation on generalized stacking fault energies of FCC metals under preloading stress

张亮, 吕程, Tieu Kiet, 赵星, 裴林清, Michal Guillaume   

  1. School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522, Australia
  • 收稿日期:2014-10-24 修回日期:2015-03-06 出版日期:2015-08-05 发布日期:2015-08-05
  • 基金资助:
    Project supported by Australia Research Council Discovery Projects (Grant No. DP130103973). L. Zhang, X. Zhao and L. Q. Pei were financially supported by the China Scholarship Council (CSC).

Molecular dynamics simulation on generalized stacking fault energies of FCC metals under preloading stress

Zhang Liang (张亮), Lü Cheng (吕程), Tieu Kiet, Zhao Xing (赵星), Pei Lin-Qing (裴林清), Michal Guillaume   

  1. School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522, Australia
  • Received:2014-10-24 Revised:2015-03-06 Online:2015-08-05 Published:2015-08-05
  • Contact: Lü Cheng E-mail:chenglu@uow.edu.cn
  • Supported by:
    Project supported by Australia Research Council Discovery Projects (Grant No. DP130103973). L. Zhang, X. Zhao and L. Q. Pei were financially supported by the China Scholarship Council (CSC).

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摘要： Molecular dynamics (MD) simulations are performed to investigate the effects of stress on generalized stacking fault (GSF) energy of three fcc metals (Cu, Al, and Ni). The simulation model is deformed by uniaxial tension or compression in each of [111], [11-2], and [1-10] directions, respectively, before shifting the lattice to calculate the GSF curve. Simulation results show that the values of unstable stacking fault energy (γusf), stable stacking fault energy (γsf), and unstable twin fault energy (γutf) of the three elements can change with the preloaded tensile or compressive stress in different directions. The ratio of γsf/γusf, which is related to the energy barrier for full dislocation nucleation, and the ratio of γutf/γusf, which is related to the energy barrier for twinning formation are plotted each as a function of the preloading stress. The results of this study reveal that the stress state can change the energy barrier of defect nucleation in the crystal lattice, and thereby can play an important role in the deformation mechanism of nanocrystalline material.

关键词: molecular dynamics, embeded atom method, generalized stacking fault

Abstract: Molecular dynamics (MD) simulations are performed to investigate the effects of stress on generalized stacking fault (GSF) energy of three fcc metals (Cu, Al, and Ni). The simulation model is deformed by uniaxial tension or compression in each of [111], [11-2], and [1-10] directions, respectively, before shifting the lattice to calculate the GSF curve. Simulation results show that the values of unstable stacking fault energy (γusf), stable stacking fault energy (γsf), and unstable twin fault energy (γutf) of the three elements can change with the preloaded tensile or compressive stress in different directions. The ratio of γsf/γusf, which is related to the energy barrier for full dislocation nucleation, and the ratio of γutf/γusf, which is related to the energy barrier for twinning formation are plotted each as a function of the preloading stress. The results of this study reveal that the stress state can change the energy barrier of defect nucleation in the crystal lattice, and thereby can play an important role in the deformation mechanism of nanocrystalline material.

Key words: molecular dynamics, embeded atom method, generalized stacking fault

中图分类号:  (Molecular nanostructures)

  • 81.07.Nb
81.07.Bc (Nanocrystalline materials) 81.40.Vw (Pressure treatment) 81.40.Jj (Elasticity and anelasticity, stress-strain relations)