中国物理B ›› 2020, Vol. 29 ›› Issue (7): 78103-078103.doi: 10.1088/1674-1056/ab8a38

• SPECIAL TOPIC—Ultracold atom and its application in precision measurement • 上一篇    下一篇

Dependence of mechanical properties on the site occupancy of ternary alloying elements in γ'-Ni3Al: Ab initio description for shear and tensile deformation

Minru Wen(文敏儒), Xing Xie(谢兴), Huafeng Dong(董华锋), Fugen Wu(吴福根), Chong-Yu Wang(王崇愚)   

  1. 1 School of Physics and Optoelectronic Engineering, Guangdong University of Technology, Guangzhou 510006, China;
    2 School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006, China;
    3 Department of Physics, Tsinghua University, Beijing 100084, China
  • 收稿日期:2020-02-12 修回日期:2020-04-08 出版日期:2020-07-05 发布日期:2020-07-05
  • 通讯作者: Huafeng Dong, Chong-Yu Wang E-mail:hfdong@gdut.edu.cn;cywang@mail.tsinghua.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 11804057), the Natural Science Foundation of Guangdong Province, China (Grant No. 2017B030306003), and the National Key Research and Development Program of China (Grant No. 2017YFB0701500).

Dependence of mechanical properties on the site occupancy of ternary alloying elements in γ'-Ni3Al: Ab initio description for shear and tensile deformation

Minru Wen(文敏儒)1, Xing Xie(谢兴)1, Huafeng Dong(董华锋)1, Fugen Wu(吴福根)2, Chong-Yu Wang(王崇愚)3   

  1. 1 School of Physics and Optoelectronic Engineering, Guangdong University of Technology, Guangzhou 510006, China;
    2 School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006, China;
    3 Department of Physics, Tsinghua University, Beijing 100084, China
  • Received:2020-02-12 Revised:2020-04-08 Online:2020-07-05 Published:2020-07-05
  • Contact: Huafeng Dong, Chong-Yu Wang E-mail:hfdong@gdut.edu.cn;cywang@mail.tsinghua.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 11804057), the Natural Science Foundation of Guangdong Province, China (Grant No. 2017B030306003), and the National Key Research and Development Program of China (Grant No. 2017YFB0701500).

摘要: The site occupancy behavior of ternary alloying elements in γ'-Ni3Al (a key strengthening phase of commercial Ni-based single-crystal superalloys) can change with temperature and alloy composition owing to the effect of entropy. Using a total-energy method based on density functional theory, the dependence of tensile and shear behaviors on the site preference of alloying elements in γ'-Ni3Al were investigated in detail. Our results demonstrate that Fe, Ru, and Ir can significantly improve the ideal tensile and shear strength of the γ' phase when occupying the Al site, with Ru resulting in the strongest enhancement. In contrast, elements with fully filled d orbitals (i.e., Cu, Zn, Ag, and Cd) are expected to reduce the ideal tensile and shear strength. The calculated stress-strain relationships of Ni3Al alloys indicate that none of the alloying elements can simultaneously increase the ideal strength of the γ' phase for both Ni1-site and Ni2-site substitutions. In addition, the charge redistribution and the bond length of the alloying elements and host atoms during the tensile and shear processes are analyzed to unveil the underlying electronic mechanisms.

关键词: stress-strain relations, transition-metal elements, γ'-Ni3Al, first-principles calculations

Abstract: The site occupancy behavior of ternary alloying elements in γ'-Ni3Al (a key strengthening phase of commercial Ni-based single-crystal superalloys) can change with temperature and alloy composition owing to the effect of entropy. Using a total-energy method based on density functional theory, the dependence of tensile and shear behaviors on the site preference of alloying elements in γ'-Ni3Al were investigated in detail. Our results demonstrate that Fe, Ru, and Ir can significantly improve the ideal tensile and shear strength of the γ' phase when occupying the Al site, with Ru resulting in the strongest enhancement. In contrast, elements with fully filled d orbitals (i.e., Cu, Zn, Ag, and Cd) are expected to reduce the ideal tensile and shear strength. The calculated stress-strain relationships of Ni3Al alloys indicate that none of the alloying elements can simultaneously increase the ideal strength of the γ' phase for both Ni1-site and Ni2-site substitutions. In addition, the charge redistribution and the bond length of the alloying elements and host atoms during the tensile and shear processes are analyzed to unveil the underlying electronic mechanisms.

Key words: stress-strain relations, transition-metal elements, γ'-Ni3Al, first-principles calculations

中图分类号:  (Elasticity and anelasticity, stress-strain relations)

  • 81.40.Jj
71.20.Be (Transition metals and alloys) 31.15.es (Applications of density-functional theory (e.g., to electronic structure and stability; defect formation; dielectric properties, susceptibilities; viscoelastic coefficients; Rydberg transition frequencies)) 71.15.Mb (Density functional theory, local density approximation, gradient and other corrections)