中国物理B ›› 2019, Vol. 28 ›› Issue (12): 126802-126802.doi: 10.1088/1674-1056/ab5277

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

Segregation behavior and embrittling effect of lanthanide La, Ce, Pr, and Nd at Σ3(111) tilt symmetric grain boundary in α-Fe

Jinli Cao(曹金利), Wen Yang(杨文), Xinfu He(贺新福)   

  1. 1 Reactor Engineering Technology Research Division, China Institute of Atomic Energy, Beijing 102413, China;
    2 School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
  • 收稿日期:2019-09-27 修回日期:2019-10-23 出版日期:2019-12-05 发布日期:2019-12-05
  • 通讯作者: Xinfu He E-mail:xinfuhe@gmail.com
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. U1867217), the National Science and Technology Major Project of the Ministry of Science and Technology of China (Grant No. 2019ZX06004009), and the China National Nuclear Corporation Centralized Research and Development Project (Grant No. FY18000120).

Segregation behavior and embrittling effect of lanthanide La, Ce, Pr, and Nd at Σ3(111) tilt symmetric grain boundary in α-Fe

Jinli Cao(曹金利)1,2, Wen Yang(杨文)1, Xinfu He(贺新福)1   

  1. 1 Reactor Engineering Technology Research Division, China Institute of Atomic Energy, Beijing 102413, China;
    2 School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
  • Received:2019-09-27 Revised:2019-10-23 Online:2019-12-05 Published:2019-12-05
  • Contact: Xinfu He E-mail:xinfuhe@gmail.com
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. U1867217), the National Science and Technology Major Project of the Ministry of Science and Technology of China (Grant No. 2019ZX06004009), and the China National Nuclear Corporation Centralized Research and Development Project (Grant No. FY18000120).

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摘要： The migration of lanthanide fission products to cladding materials is recognized as one of the key causes of fuel-cladding chemical interaction (FCCI) in metallic fuels during operation. We have performed first-principles density functional theory calculations to investigate the segregation behavior of lanthanide fission products (La, Ce, Pr, and Nd) and their effects on the intergranular embrittlement at Σ3(111) tilt symmetric grain boundary (GB) in α-Fe. It is found that La and Ce atoms tend to reside at the first layer near the GB with segregation energies of -2.55 eV and -1.60 eV, respectively, while Pr and Nd atoms prefer to the core mirror plane of the GB with respective segregation energies of -1.41 eV and -1.50 eV. Our calculations also show that La, Ce, Pr, and Nd atoms all act as strong embrittlers with positive strengthening energies of 2.05 eV, 1.52 eV, 1.50 eV, and 1.64 eV, respectively, when located at their most stable sites. The embrittlement capability of four lanthanide elements can be determined by the atomic size and their magnetism characters. The present calculations are helpful for understanding the behavior of fission products La, Ce, Pr, and Nd in α-Fe.

关键词: first-principles, fuel-cladding chemical interaction (FCCI), fission products, grain boundary segregation

Abstract: The migration of lanthanide fission products to cladding materials is recognized as one of the key causes of fuel-cladding chemical interaction (FCCI) in metallic fuels during operation. We have performed first-principles density functional theory calculations to investigate the segregation behavior of lanthanide fission products (La, Ce, Pr, and Nd) and their effects on the intergranular embrittlement at Σ3(111) tilt symmetric grain boundary (GB) in α-Fe. It is found that La and Ce atoms tend to reside at the first layer near the GB with segregation energies of -2.55 eV and -1.60 eV, respectively, while Pr and Nd atoms prefer to the core mirror plane of the GB with respective segregation energies of -1.41 eV and -1.50 eV. Our calculations also show that La, Ce, Pr, and Nd atoms all act as strong embrittlers with positive strengthening energies of 2.05 eV, 1.52 eV, 1.50 eV, and 1.64 eV, respectively, when located at their most stable sites. The embrittlement capability of four lanthanide elements can be determined by the atomic size and their magnetism characters. The present calculations are helpful for understanding the behavior of fission products La, Ce, Pr, and Nd in α-Fe.

Key words: first-principles, fuel-cladding chemical interaction (FCCI), fission products, grain boundary segregation

中图分类号:  (Nucleation and growth)

  • 68.55.A-
71.15.Mb (Density functional theory, local density approximation, gradient and other corrections) 71.15.Nc (Total energy and cohesive energy calculations)