中国物理B ›› 2017, Vol. 26 ›› Issue (7): 76106-076106.doi: 10.1088/1674-1056/26/7/076106

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

Molecular dynamics simulations of cascade damage near the Y2Ti2O7 nanocluster/ferrite interface in nanostructured ferritic alloys

Yi-Qiang Sun(孙祎强), Wen-Sheng Lai(赖文生)   

  1. Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
  • 收稿日期:2017-03-18 修回日期:2017-04-12 出版日期:2017-07-05 发布日期:2017-07-05
  • 通讯作者: Wen-Sheng Lai E-mail:wslai@tsinghua.edu.cn
  • 基金资助:

    Project supported by the Science Challenge Project of China (Grant No.TZ2016002) and the National Natural Science Foundation of China (Grant No.50871057).

Molecular dynamics simulations of cascade damage near the Y2Ti2O7 nanocluster/ferrite interface in nanostructured ferritic alloys

Yi-Qiang Sun(孙祎强), Wen-Sheng Lai(赖文生)   

  1. Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
  • Received:2017-03-18 Revised:2017-04-12 Online:2017-07-05 Published:2017-07-05
  • Contact: Wen-Sheng Lai E-mail:wslai@tsinghua.edu.cn
  • Supported by:

    Project supported by the Science Challenge Project of China (Grant No.TZ2016002) and the National Natural Science Foundation of China (Grant No.50871057).

摘要:

A comparative study of cascades in nanostructured ferritic alloys and pure Fe is performed to reveal the influence of Y2Ti2O7 nanocluster on cascades by molecular dynamics simulations. The cascades with energies of primary knock-on atom (PKA) ranging from 0.5 keV to 4.0 keV and PKA's distances to the interface from 0 Å to 50 Å are simulated. It turns out that the Y2Ti2O7 nanocluster can absorb the kinetic energy of cascade atoms, prevent the cascade from extending and reduce the defect production significantly when the cascades overlap with the nanocluster. When the cascade affects seriously the nanocluster, the weak sub-cascade collisions are rebounded by the nanocluster and thus leave more interstitials in the matrix. On the contrary, when the cascade contacts weakly the nanocluster, the interface can pin the arrived interstitials and this leaves more vacancies in the matrix. Moreover, the results indicate that the Y2Ti2O7 nanocluster keeps stable upon the displacement cascade damage.

关键词: nanostructured ferritic alloys, molecular dynamics simulation, Y2Ti2O7, displacement cascade

Abstract:

A comparative study of cascades in nanostructured ferritic alloys and pure Fe is performed to reveal the influence of Y2Ti2O7 nanocluster on cascades by molecular dynamics simulations. The cascades with energies of primary knock-on atom (PKA) ranging from 0.5 keV to 4.0 keV and PKA's distances to the interface from 0 Å to 50 Å are simulated. It turns out that the Y2Ti2O7 nanocluster can absorb the kinetic energy of cascade atoms, prevent the cascade from extending and reduce the defect production significantly when the cascades overlap with the nanocluster. When the cascade affects seriously the nanocluster, the weak sub-cascade collisions are rebounded by the nanocluster and thus leave more interstitials in the matrix. On the contrary, when the cascade contacts weakly the nanocluster, the interface can pin the arrived interstitials and this leaves more vacancies in the matrix. Moreover, the results indicate that the Y2Ti2O7 nanocluster keeps stable upon the displacement cascade damage.

Key words: nanostructured ferritic alloys, molecular dynamics simulation, Y2Ti2O7, displacement cascade

中图分类号:  (Physical radiation effects, radiation damage)

  • 61.80.-x
28.41.Qb (Structural and shielding materials) 02.70.Ns (Molecular dynamics and particle methods)