中国物理B ›› 2006, Vol. 15 ›› Issue (9): 2087-2091.doi: 10.1088/1009-1963/15/9/031

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Molecular dynamics study of mosaic structure in the Ni-based single-crystal superalloy

王崇愚1, 朱弢2   

  1. (1)Central Iron and Steel Research Institute, Beijing 100081, China;Department of Physics, Tsinghua University, Beijing 100084, China; (2)Central Iron and Steel Research Institute, Beijing 100081, China;Jinan Iron and Steel Group Corporation, Jinan 250101,China
  • 收稿日期:2006-04-10 修回日期:2006-05-29 出版日期:2006-09-20 发布日期:2006-09-20
  • 基金资助:
    Project supported by the State Key Development Program for Basic Research of China (Grant No G2000067102) and the National Natural Science Foundation of China (Grant No 90101004).

Molecular dynamics study of mosaic structure in the Ni-based single-crystal superalloy

Zhu Tao(朱弢)a)c)† and Wang Chong-Yu(王崇愚)a)b)   

  1. a Central Iron and Steel Research Institute, Beijing 100081, Chinab Department of Physics, Tsinghua University, Beijing 100084, China; c Jinan Iron and Steel Group Corporation, Jinan 250101, China
  • Received:2006-04-10 Revised:2006-05-29 Online:2006-09-20 Published:2006-09-20
  • Supported by:
    Project supported by the State Key Development Program for Basic Research of China (Grant No G2000067102) and the National Natural Science Foundation of China (Grant No 90101004).

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摘要： The mosaic structure in a Ni-based single-crystal superalloy is simulated by molecular dynamics using a potential employed in a modified analytic embedded atom method. From the calculated results we find that a closed three-dimensional misfit dislocation network, with index of $\langle 011\rangle${\{}100{\}} and the side length of the mesh 89.6\,{\AA}, is formed around a cuboidal $\gamma '$ precipitate. Comparing the simulation results of the different mosaic models, we find that the side length of the mesh only depends on the lattice parameters of the $\gamma $ and $\gamma '$ phases as well as the $\gamma $/$\gamma '$ interface direction, but is independent of the size and number of the cuboidal $\gamma '$ precipitate. The density of dislocations is inversely proportional to the size of the cuboidal $\gamma '$ precipitate, i.e.~the amount of the dislocation is proportional to the total area of the $\gamma $/$\gamma '$ interface, which may be used to explain the relation between the amount of the fine $\gamma '$ particles and the creep rupture life of the superalloy. In addition, the closed three-dimensional networks assembled with the misfit dislocations can play a significant role in improving the mechanical properties of superalloys.

关键词: Ni-based single-crystal superalloy, mosaic structure, molecular dynamics simulation

Abstract: The mosaic structure in a Ni-based single-crystal superalloy is simulated by molecular dynamics using a potential employed in a modified analytic embedded atom method. From the calculated results we find that a closed three-dimensional misfit dislocation network, with index of $\langle 011\rangle${100} and the side length of the mesh 89.6?, is formed around a cuboidal $\gamma '$ precipitate. Comparing the simulation results of the different mosaic models, we find that the side length of the mesh only depends on the lattice parameters of the $\gamma $ and $\gamma '$ phases as well as the $\gamma $/$\gamma '$ interface direction, but is independent of the size and number of the cuboidal $\gamma '$ precipitate. The density of dislocations is inversely proportional to the size of the cuboidal $\gamma '$ precipitate, i.e.~the amount of the dislocation is proportional to the total area of the $\gamma $/$\gamma '$ interface, which may be used to explain the relation between the amount of the fine $\gamma '$ particles and the creep rupture life of the superalloy. In addition, the closed three-dimensional networks assembled with the misfit dislocations can play a significant role in improving the mechanical properties of superalloys.

Key words: Ni-based single-crystal superalloy, mosaic structure, molecular dynamics simulation

中图分类号:  (Quasicrystals)

  • 61.44.Br
63.20.-e (Phonons in crystal lattices) 62.20.D- (Elasticity)