中国物理B ›› 2017, Vol. 26 ›› Issue (9): 93106-093106.doi: 10.1088/1674-1056/26/9/093106
• ATOMIC AND MOLECULAR PHYSICS • 上一篇 下一篇
Lattice stability and the effect of Co and Re on the ideal strength of Ni: First-principles study of uniaxial tensile deformation
Minru Wen(文敏儒), Chong-Yu Wang(王崇愚)
- Department of Physics, Tsinghua University, Beijing 100084, China
Lattice stability and the effect of Co and Re on the ideal strength of Ni: First-principles study of uniaxial tensile deformation
Minru Wen(文敏儒), Chong-Yu Wang(王崇愚)
- Department of Physics, Tsinghua University, Beijing 100084, China
摘要：
Using first-principles density functional calculations, lattice stability of γ-Ni under [001], [110], and [111] uniaxial tensions and the effect of alloying elements Co and Re on the uniaxial tensile behavior of γ-Ni were studied in this paper. With elastic constants and phonon spectra calculations, we examined the mechanical stability and phonon stability of Ni during the uniaxial tensions along the three characteristic directions. The results show that the mechanical stability and phonon stability of a lattice occurs before the maximum stress-strain point under the [001] and [111] tension, respectively. The effects of Co and Re on the ideal tensile strength of γ-Ni show a significant directivity: Co and Re have little effect on the stresses in [001] and [111] directions, but increases the ideal strength of the system in the weakest uniaxial tensile direction. Moreover, the strengthening effect of Re is significantly better than that of Co. By further analyzing electronic structure, it is found that the effect of alloying elements on the uniaxial tensile behavior of γ-Ni comes from their interactions with host atoms.
中图分类号: (Applications of density-functional theory (e.g., to electronic structure and stability; defect formation; dielectric properties, susceptibilities; viscoelastic coefficients; Rydberg transition frequencies))
- 31.15.es