中国物理B ›› 2012, Vol. 21 ›› Issue (9): 93104-093104.doi: 10.1088/1674-1056/21/9/093104

• ATOMIC AND MOLECULAR PHYSICS • 上一篇    下一篇

Brittle-ductile behavior of a nanocrack in nanocrystalline Ni: A quasicontinuum study

邵宇飞a, 杨鑫a, 赵星b, 王绍青c   

  1. a Institute of Applied Physics and Technology, Department of General Studies, Liaoning Technical University, Huludao 125105, China;
    b Department of Mathematics and Physics, Liaoning University of Technology, Jinzhou 121001, China;
    c Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
  • 收稿日期:2011-12-23 修回日期:2012-03-12 出版日期:2012-08-01 发布日期:2012-08-01
  • 基金资助:
    Project supported by the National Basic Research Program of China (Grant No. 2011CB606403).

Brittle-ductile behavior of a nanocrack in nanocrystalline Ni: A quasicontinuum study

Shao Yu-Fei (邵宇飞)a, Yang Xin (杨鑫)a, Zhao Xing (赵星)b, Wang Shao-Qing (王绍青)c   

  1. a Institute of Applied Physics and Technology, Department of General Studies, Liaoning Technical University, Huludao 125105, China;
    b Department of Mathematics and Physics, Liaoning University of Technology, Jinzhou 121001, China;
    c Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
  • Received:2011-12-23 Revised:2012-03-12 Online:2012-08-01 Published:2012-08-01
  • Contact: Zhao Xing E-mail:yfshao@alum.imr.ac.cn; zhao-heng-xing@126.com
  • Supported by:
    Project supported by the National Basic Research Program of China (Grant No. 2011CB606403).

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摘要： The effects of stacking fault energy, unstable stacking fault energy and unstable twinning fault energy on the fracture behavior of nanocrystalline Ni are studied via the quasicontinuum simulations. Two semi-empirical potentials for Ni are used to vary the values of these generalized planar fault energies. When the above three energies are reduced, a brittle-to-ductile transition of the fracture behavior is observed. In the model with higher generalized planar fault energies, a nanocrack proceeds along a grain boundary, while in the model with lower energies, the tip of the nanocrack becomes blunt. A greater twinning tendency is also observed in the more ductile model. These results indicate that the fracture toughness of nanocrystalline face-centered-cubic metals and alloys might be efficiently improved by controlling the generalized planar fault energies.

关键词: atomistic simulations, nanocrystalline materials, fracture, grain boundaries

Abstract: The effects of stacking fault energy, unstable stacking fault energy and unstable twinning fault energy on the fracture behavior of nanocrystalline Ni are studied via the quasicontinuum simulations. Two semi-empirical potentials for Ni are used to vary the values of these generalized planar fault energies. When the above three energies are reduced, a brittle-to-ductile transition of the fracture behavior is observed. In the model with higher generalized planar fault energies, a nanocrack proceeds along a grain boundary, while in the model with lower energies, the tip of the nanocrack becomes blunt. A greater twinning tendency is also observed in the more ductile model. These results indicate that the fracture toughness of nanocrystalline face-centered-cubic metals and alloys might be efficiently improved by controlling the generalized planar fault energies.

Key words: atomistic simulations, nanocrystalline materials, fracture, grain boundaries

中图分类号:  (Molecular dynamics and other numerical methods)

  • 31.15.xv
61.72.Mm (Grain and twin boundaries) 62.20.mt (Cracks) 61.82.Rx (Nanocrystalline materials)