中国物理B ›› 2018, Vol. 27 ›› Issue (7): 77103-077103.doi: 10.1088/1674-1056/27/7/077103

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Anisotropic elastic properties and ideal uniaxial compressive strength of TiB2 from first principles calculations

Min Sun(孙敏), Chong-Yu Wang(王崇愚), Ji-Ping Liu(刘吉平)   

  1. 1 School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081, China;
    2 Department of Physics, Tsinghua University, Beijing 100084, China
  • 收稿日期:2018-06-15 出版日期:2018-07-05 发布日期:2018-07-05
  • 通讯作者: Chong-Yu Wang, Ji-Ping Liu E-mail:cywang@mail.tsinghua.edu.cn;ilphysics@163.com

Anisotropic elastic properties and ideal uniaxial compressive strength of TiB2 from first principles calculations

Min Sun(孙敏)1, Chong-Yu Wang(王崇愚)2, Ji-Ping Liu(刘吉平)1   

  1. 1 School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081, China;
    2 Department of Physics, Tsinghua University, Beijing 100084, China
  • Received:2018-06-15 Online:2018-07-05 Published:2018-07-05
  • Contact: Chong-Yu Wang, Ji-Ping Liu E-mail:cywang@mail.tsinghua.edu.cn;ilphysics@163.com

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摘要： The structural, anisotropic elastic properties and the ideal compressive and tensile strengths of titanium diboride (TiB2) were investigated using first-principles calculations based on density functional theory. The stress-strain relationships of TiB2 under <1010>, <1210>, and <0001> compressive loads were calculated. Our results showed that the ideal uniaxial compressive strengths are |σ<1210>|=142.96 GPa,|σ<0001>|=188.75 GPa, and |σ<1010>|=245.33 GPa, at strains-0.16,-0.32, and-0.24, respectively. The variational trend is just the opposite to that of the ideal tensile strength with σ<1010>=44.13 GPa, σ<0001>=47.03 GPa, and σ<1210>=56.09 GPa, at strains 0.14, 0.28, and 0.22, respectively. Furthermore, it was found that TiB2 is much stronger under compression than in tension. The ratios of the ideal compressive to tensile strengths are 5.56, 2.55, and 4.01 for crystallographic directions <1010>, <1210>, and <0001>, respectively. The present results are in excellent agreement with the most recent experimental data and should be helpful to the understanding of the compressive property of TiB2.

关键词: ideal compressive strength, electronic structure, elastic property, first principles calculation

Abstract: The structural, anisotropic elastic properties and the ideal compressive and tensile strengths of titanium diboride (TiB2) were investigated using first-principles calculations based on density functional theory. The stress-strain relationships of TiB2 under <1010>, <1210>, and <0001> compressive loads were calculated. Our results showed that the ideal uniaxial compressive strengths are |σ<1210>|=142.96 GPa,|σ<0001>|=188.75 GPa, and |σ<1010>|=245.33 GPa, at strains-0.16,-0.32, and-0.24, respectively. The variational trend is just the opposite to that of the ideal tensile strength with σ<1010>=44.13 GPa, σ<0001>=47.03 GPa, and σ<1210>=56.09 GPa, at strains 0.14, 0.28, and 0.22, respectively. Furthermore, it was found that TiB2 is much stronger under compression than in tension. The ratios of the ideal compressive to tensile strengths are 5.56, 2.55, and 4.01 for crystallographic directions <1010>, <1210>, and <0001>, respectively. The present results are in excellent agreement with the most recent experimental data and should be helpful to the understanding of the compressive property of TiB2.

Key words: ideal compressive strength, electronic structure, elastic property, first principles calculation

中图分类号:  (Density functional theory, local density approximation, gradient and other corrections)

  • 71.15.Mb
71.15.-m (Methods of electronic structure calculations) 81.05.Je (Ceramics and refractories (including borides, carbides, hydrides, nitrides, oxides, and silicides)) 62.20.-x (Mechanical properties of solids)