Influence of doping concentration on mechanical properties of Mo2FeB2 alloyed with Cr and Ni from first-principle calculations

Through the first-principle calculations based on density functional theory and experimental investigation, the structural stability elastic properties and mechanical properties of Ti2Cu and Ti18Cu5Nb1 intermetallics were studied. The first-principle calculations showed that the ratio of bulk modulus to shear modulus (B/G) and Poisson’s ratio (ν) of Ti2Cu and Ti18Cu5Nb1 intermetallics were 2.03, 0.288, and 2.22, 0.304, respectively, indicating that the two intermetallics were ductile. This was confirmed by the compression tests, which showed that the plastic strain of both intermetallics was beyond 25%. In addition, the yield strength increased from the 416 to 710 MPa with the addition of Nb. The increase in strength is the result of three factors, namely covalent bond tendency, fine grain strengthening, and solid solution strengthening. This finding gives clues to design novel intermetallics with excellent mechanical properties by first-principle calculations and alloying.

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Vacancy-induced elastic properties and hardness of CrB4: A DFT calculation

International Journal of Modern Physics B ◽

10.1142/s0217979217500965 ◽

2017 ◽

Vol 31 (13) ◽

pp. 1750096 ◽

Cited By ~ 1

Author(s):

Yong Pan ◽

Song Chen ◽

Yuanhua Lin

Keyword(s):

Mechanical Properties ◽

Dft Calculation ◽

Covalent Bond ◽

Elastic Stiffness ◽

First Principle ◽

Triangular Pyramid ◽

First Principle Calculations ◽

3D Network ◽

Metal Borides ◽

The Relationship

Vacancy plays a crucial role in mechanical properties of transition metal borides (TMBs). However, the influence of vacancy on hardness of TMBs is unknown. In this paper, the relationship between boron vacancy and mechanical properties of CrB4 is investigated by first-principle calculations. Two different vacancies including boron monovacancy (MV) and boron bivacancy (BV) are considered. We find that CrB4 with boron MV is more stable than that of boron BV. The removed atom weakens the deformation resistances, and reduces the elastic stiffness and hardness. The calculated shear modulus, Young’s modulus and theoretical hardness of boron MV are larger than that of boron BV. The reason is that the removed atom weakens the localized hybridization between B and B atoms, and damages the 3D-network B–B covalent bond. However, the bulk modulus of B[Formula: see text] is slightly larger than that of perfect CrB4. This reason is attributed to the formation of triangular pyramid bonding in B[Formula: see text] vacancy.

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Theoretical Study of the Effect of Ca Doping on the Electronic Properties of LiCoO2

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.415-417.1643 ◽

2011 ◽

Vol 415-417 ◽

pp. 1643-1646 ◽

Cited By ~ 2

Author(s):

Zhen Hui Sun ◽

Wei Hua Liu ◽

Qi Xin Wan ◽

Dong Mei Li ◽

Zhi Hua Xiong

Keyword(s):

Band Structure ◽

Electronic Properties ◽

Crystalline Structure ◽

Doping Concentration ◽

Theoretical Study ◽

First Principle ◽

Ca Doping ◽

First Principle Calculations ◽

Densities Of States ◽

Valence Bands

Based on the first-principle calculations, we present a study of the effect of Ca doping on the electronic properties of LiCoO2. Studies of band structure and densities of states show that hole states, which enhance the conductivity of semiconductor appear in the valence bands of Ca-doped material due to the increase of Co4+concentration. It is further found that the Ca doping concentration should be controlled within 10 mol% of LiCoO2to keep the crystalline structure unchanged. We expect this study might be helpful for synthesizing good conductivity LiCoO2by controlling Ca doping.

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