Effect of Mn doping on mechanical properties and electronic structure of WCoB ternary boride by first-principles calculations

2018 ◽  
Vol 27 (10) ◽  
pp. 107101 ◽  
Author(s):  
Tong Zhang ◽  
Hai-Qing Yin ◽  
Cong Zhang ◽  
Xuan-Hui Qu ◽  
Qing-Jun Zheng
Keyword(s):  
Mechanical Properties ◽  
Electronic Structure ◽  
First Principles ◽  
First Principles Calculations ◽  
Mn Doping ◽  
Ternary Boride

Effect of Cr doping on the mechanical properties and electronic structure of WCoB ternary boride by first-principles calculations

2018 ◽  
Vol 32 (21) ◽  
pp. 1850240 ◽  
Author(s):  
Tong Zhang ◽  
Haiqing Yin ◽  
Cong Zhang ◽  
Xuanhui Qu ◽  
Qingjun Zheng
Keyword(s):  
Mechanical Properties ◽  
Electronic Structure ◽  
Structural Stability ◽  
First Principles ◽  
Formation Enthalpy ◽  
First Principles Calculations ◽  
Metal Interactions ◽  
Metal Metal ◽  
Ternary Boride ◽  
Cr Doping

The lattice parameters, structural stability, mechanical properties, hardness and electronic structure of WCoB with Cr alloying were investigated by using first-principles calculations. The Cr atom was selected to replace 0, 1, 2, 3, 4 Co atoms in WCoB crystal and 0, 1, 2 Co atoms in W2CoB2 crystal. The calculated cohesive energy and formation enthalpy showed that all structures can retain good structural stability with different Cr doping content. The calculated mechanical properties showed Cr doping will decrease the shear modulus, Young’s modulus, bulk modulus and hardness, but increase the ductility. The larger number of valence electrons of Cr led to the increasing of bond covalence and population. According to the electronic structures analysis, the nonmetal–metal hybridization and metal–metal interactions contributed to relatively high toughness.

scholarly journals First-principles study on the effects of N and Al doping on the mechanical properties and electronic structures of TiC

RSC Advances ◽  
2020 ◽  
Vol 10 (60) ◽  
pp. 36295-36302
Author(s):  
Zhinan Cao ◽  
Na Jin ◽  
Jinwen Ye ◽  
Xu Du ◽  
Ying Liu
Keyword(s):  
Mechanical Properties ◽  
Electronic Structure ◽  
Plane Wave ◽  
First Principles ◽  
Electronic Structures ◽  
First Principles Calculations ◽  
Al Doping ◽  
First Principles Study

First-principles calculations are carried out by DFT within the CASTEP plane wave code to investigate the mechanical properties and electronic structure of N and Al doped TiC.

First-principles study on the electronic structure and elastic properties of Mo2NiB2 doped with V

2018 ◽  
Vol 32 (10) ◽  
pp. 1850065 ◽  
Author(s):  
Jinming Li ◽  
Xiaobo Li ◽  
Haiyun Gao ◽  
Dian Peng
Keyword(s):  
Electronic Structure ◽  
Elastic Properties ◽  
Density Of States ◽  
First Principles ◽  
Density Functional ◽  
Mechanical Stability ◽  
Formation Enthalpy ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Ternary Boride

The content of this study is to analyze the electronic structure and elastic properties that the different structures of Mo2NiB2 and doping with V of the tetragonal M3B2 (Mo2Ni[Formula: see text]V[Formula: see text]B2 and Mo[Formula: see text]Ni[Formula: see text]V[Formula: see text]B2) (x = 0.25, 0.5, 0.75 and y = 0.125, 0.25, 0.375) by first-principles calculations based on density functional theory (DFT) combined with the projection-plus-wave method. But the calculated formation energy shows that V atoms prefer to substitute the Mo and Ni atoms of the tetragonal Mo2NiB2. Moreover, with the increase of V content, the formation enthalpy of tetragonal Mo2NiB2 is reduced, and the formation enthalpy of Mo[Formula: see text]Ni[Formula: see text]V[Formula: see text]B2 is the least as −53.23 kJ/mol. The calculated elastic constant suffices the condition of mechanical stability, indicate that they are stable. The calculated elastic modulus illustrates that Mo2NiB2 having better mechanical properties when V elements are at Mo and Ni sites instead of Ni sites. The calculated and analyzed density of states of Mo[Formula: see text]Ni[Formula: see text]V[Formula: see text]B2 has the smallest the density of states at the Fermi level indicating that it has the more stable structure. For the theoretical analysis of the first-principles calculations, the addition of 15 atom% of the V and V doping modes of Mo and Ni are preferentially replaced by V atoms of Mo2NiB2 ternary boride has the best performance.

scholarly journals A First-Principles Study of the Cu-Containing β″ Precipitates in Al-Mg-Si-Cu Alloy

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7879
Author(s):  
Shaozhi He ◽  
Jiong Wang ◽  
Donglan Zhang ◽  
Qing Wu ◽  
Yi Kong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electronic Structure ◽  
First Principles ◽  
Density Functional ◽  
Electron Interaction ◽  
Structure Stability ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Cu Alloy ◽  
Work First

The nanostructured β″ precipitates are critical for the strength of Al-Mg-Si-(Cu) aluminum alloys. However, there are still controversial reports about the composition of Cu-containing β″ phases. In this work, first-principles calculations based on density functional theory were used to investigate the composition, mechanical properties, and electronic structure of Cu-containing β″ phases. The results predict that the Cu-containing β″ precipitates with a stoichiometry of Mg4+xAl2−xCuSi4 (x = 0, 1) are energetically favorable. As the concentration of Cu atoms increases, Cu-containing β″ phases with different compositions will appear, such as Mg4AlCu2Si4 and Mg4Cu3Si4. The replacement order of Cu atoms in β″ phases can be summarized as one Si3/Al site → two Si3/Al sites → two Si3/Al sites and one Mg1 site. The calculated elastic constants of the considered β″ phases suggest that they are all mechanically stable, and all β″ phases are ductile. When Cu atoms replace Al atoms at Si3/Al sites in β″ phases, the values of bulk modulus (B), shear modulus (G), and Young’s modulus (E) all increase. The calculation of the phonon spectrum shows that Mg4+xAl2−xCuSi4 (x = 0, 1) are also dynamically stable. The electronic structure analysis shows that the bond between the Si atom and the Cu atom has a covalent like property. The incorporation of the Cu atom enhances the electron interaction between the Mg2 and the Si3 atom so that the Mg2 atom also joins the Si network, which may be one of the reasons why Cu atoms increase the structure stability of the β″ phases.

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