Anisotropy in elasticity and physical properties of Ti 2 B under high pressure

Physica Status Solidi (b)

Liu

Zhao

et al. 2020

Self Cite

The physical properties of Cr2B with I4/m symmetry under pressure are investigated by the first‐principles method. With the increase in pressure, the hardness decreases first and then slightly increases, whereas the bulk modulus, shear modulus, Young's modulus, fracture toughness, minimum thermal conductivity, and Debye temperature monotonically increase. Pressure induces the transition from brittleness to toughness at ≈30 GPa. When P > 30 GPa, the hardness and toughness increase simultaneously with pressure. The analysis of electronic structure indicates that the variation of BB covalent bonds may be responsible for the abnormous increase in hardness when P > 30 GPa.

Section: Introductionmentioning

confidence: 65%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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Physical Properties and Electronic Structure of Cr₂B Under Pressure

Physica Status Solidi (b)

Liu

Zhao

et al. 2020

Self Cite

“…The lattice constant 7.451 Å of Zr 0.5 Y 0.5 B 12 is also consistent with the result 7.454 Å obtained from the cell refinement using Maud and 7.459 Å calculated using Vegard's law [3], which indicates the parameters in our calculation are reliable. The polycrystalline bulk modulus B, shear modulus G, Young's modulus E and Poisson's ratio σ are obtained using the elastic constants [16]. The Vickers hardness of materials can be obtained by Chen's model [17] and Gao's model [18].…”

Section: Computational Methods and Theorymentioning

confidence: 99%

Anisotropy in elasticity, sound velocity, thermal conductivity, and thermodynamics properties of dodecaboride Zr_0.5Y_0.5B₁₂

Int J of Quantum Chemistry

Wang

et al. 2021

Self Cite

Solid solution of metal dodecaboride Zr 0.5 Y 0.5 B 12 is thermodynamically stable. The anisotropies of Zr 0.5 Y 0.5 B 12 in linear compressibility, Young's modulus, shear modulus, sound velocity, and minimum thermal conductivity are discussed. The linear compressibility shows slightly anisotropy, which arises from the atomic size mismatch between Zr and Y. Young's and shear modulus present significant anisotropy. The sound velocities show weak anisotropy in different planes, except the pure transverse mode v t in (010) plane, which shows isotropic. The minimum thermal conductivities in different planes are comparable and show very weak anisotropy. The effects of temperature and pressure on the thermal expansion coefficient, Debye temperature, and Grüneisen parameter are discussed based on the quasi-harmonic Debye model.

“…The polycrystalline bulk modulus B and shear modulus G are obtained from the Voigt-Reuss-Hill (VRH) approximation, 18) Young's modulus E and Poisson's ratio σ are obtained using the equation of Ref. 19. Hardness of a material reflects the resistance to elastic and plastic deformation.…”

mentioning

confidence: 99%

Elastic anisotropy and physical properties of semi-transition-metal borides: first-principles calculation

Liu

Shi

et al. 2019

Appl. Phys. Express

Self Cite

The elastic anisotropy, mechanical and thermal properties of semi-transition-metal (TM) borides with I4/m symmetry have been investigated using the first-principles method. Compared with other TM2B compounds, Cr2B shows the most brittle and largest shear modulus, Young’s modulus, Vickers hardness, Debye temperature (ΘD) and minimum thermal conductivity (κmin) with the relatively higher bulk modulus and fracture toughness. Due to the effect of volume, the slight difference has been found in the order of ΘD and κmin between Ta2B and W2B. Except Ti2B, TM2B compounds show weak elastic anisotropy.