中国物理B ›› 2012, Vol. 21 ›› Issue (10): 109102-109102.doi: 10.1088/1674-1056/21/10/109102

• GEOPHYSICS, ASTRONOMY, AND ASTROPHYSICS • 上一篇    下一篇

First principles calculations of alloying element diffusion coefficients in Ni using the five-frequency model

吴琼, 李树索, 马岳, 宫声凯   

  1. School of Materials Science and Engineering, Beihang University, Beijing 100191, China
  • 收稿日期:2012-02-29 修回日期:2012-05-08 出版日期:2012-09-01 发布日期:2012-09-01
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 50971005).

First principles calculations of alloying element diffusion coefficients in Ni using the five-frequency model

Wu Qiong (吴琼), Li Shu-Suo (李树索), Ma Yue (马岳), Gong Sheng-Kai (宫声凯)   

  1. School of Materials Science and Engineering, Beihang University, Beijing 100191, China
  • Received:2012-02-29 Revised:2012-05-08 Online:2012-09-01 Published:2012-09-01
  • Contact: Wu Qiong, Gong Sheng-Kai E-mail:queong@126.com; gongsk@buaa.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 50971005).

摘要: The diffusion coefficients of several alloying elements (Al, Mo, Co, Ta, Ru, W, Cr, Re) in Ni are directly calculated using the five-frequency model and the first principles density functional theory. The correlation factors provided by the five-frequency model are explicitly calculated. The calculated diffusion coefficients show their excellent agreement with the available experimental data. Both the diffusion pre-factor (D0) and the activation energy (Q) of impurity diffusion are obtained. The diffusion coefficients above 700 K are sorted in the following order: DAl>DCr>DCo>DTa>DMo>DRu>DW>DRe. It is found that there is a positive correlation between the atomic radius of the solute and the jump energy of Ni that results in the rotation of the solute-vacancy pair (E1). The value of E2-E1 (E2 is the solute diffusion energy) and the correlation factor each also show a positive correlation. The larger atoms in the same series have lower diffusion activation energies and faster diffusion coefficients.

关键词: first-principles theory, diffusion coefficients, alloying element, superalloy, activation energy and diffusion pre-factor

Abstract: The diffusion coefficients of several alloying elements (Al, Mo, Co, Ta, Ru, W, Cr, Re) in Ni are directly calculated using the five-frequency model and the first principles density functional theory. The correlation factors provided by the five-frequency model are explicitly calculated. The calculated diffusion coefficients show their excellent agreement with the available experimental data. Both the diffusion pre-factor (D0) and the activation energy (Q) of impurity diffusion are obtained. The diffusion coefficients above 700 K are sorted in the following order: DAl>DCr>DCo>DTa>DMo>DRu>DW>DRe. It is found that there is a positive correlation between the atomic radius of the solute and the jump energy of Ni that results in the rotation of the solute-vacancy pair (E1). The value of E2-E1 (E2 is the solute diffusion energy) and the correlation factor each also show a positive correlation. The larger atoms in the same series have lower diffusion activation energies and faster diffusion coefficients.

Key words: first-principles theory, diffusion coefficients, alloying element, superalloy, activation energy and diffusion pre-factor

中图分类号:  (Plasticity, diffusion, and creep)

  • 91.60.Dc
66.10.C- (Diffusion and thermal diffusion) 66.10.cg (Mass diffusion, including self-diffusion, mutual diffusion, tracer diffusion, etc.) 66.30.-h (Diffusion in solids)