A DFT study on pressure dependency of TiC and ZrC properties: Interconnecting elastic constants, thermodynamic, and mechanical properties

Author(s):  
M. Khanzadeh ◽  
Gh Alahyarizadeh
2011 ◽  
Vol 378-379 ◽  
pp. 7-10
Author(s):  
Gui Xue Bian ◽  
Yue Liang Chen ◽  
Jian Jun Hu ◽  
Li Xu

Molecular dynamics simulation was used to simulate the tension process of purity and containing impurity metal aluminum. Elastic constants of purity and containing impurity metal aluminum were calculated, and the effects of impurity on the elastic constants were also studied. The results show that O-Al bond and Al-Al bond near oxygen atoms could be the sites of crack nucleation or growth under tensile load, the method can be extended to research mechanical properties of other metals and alloys structures.


2018 ◽  
Vol 53 (2) ◽  
pp. 197-208 ◽  
Author(s):  
Shan-yuan Jiang ◽  
Hao Wang ◽  
Zhong-wei Wang

Variabilities of mesostructures existing in textile composites can affect their mechanical properties. Most of the deterministic mechanical models are based on the assumptions of ideal Representative Volume Element, which cannot predict the mechanical properties accurately. Two analytical models predicting the elastic constants of C/Epoxy plain-weave composites by considering the realistic mesostructures are presented in this paper. These models utilize the variable metric stochastic theory to introduce the fluctuations of yarn feature parameters (yarn path and elliptical cross-section parameters) into the model of macro elastic properties. C/Epoxy plain-weave composite is taken as an example to quantify the influences of realistic yarn feature parameters on the elastic constants of the composite. The predicted elastic constants by analytical models and finite element method are verified by the results of mechanical experiments. It can be concluded that for C/Epoxy plain-weave composite the stochastic fluctuations of yarn feature parameters reduce in-plane elastic moduli by a maximum of 4%, and increase the in-plane shear modulus and Poisson’s ratio by a maximum of 15% and 33%, respectively.


2014 ◽  
Vol 887-888 ◽  
pp. 378-383 ◽  
Author(s):  
Yu Chen ◽  
Zheng Jun Yao ◽  
Ping Ze Zhang ◽  
Dong Bo Wei ◽  
Xi Xi Luo ◽  
...  

The structure stability, mechanical properties and electronic structures of B2 phase FeAl intermetallic compounds and FeAl ternary alloys containing V, Cr or Ni were investigated using first-principles density functional theory calculations. Several models are established. The total energies, cohesive energies, lattice constants, elastic constants, density of states, and the charge densities of Fe8Al8 and Fe8XAl7 ( X=V, Cr, Ni ) are calculated. The stable crystal structures of alloy systems are determined due to the cohesive energy results. The calculated lattice contants of Fe-Al-X ( X= V, Cr, Ni) were found to be related to the atomic radii of the alloy elements. The calculation and analysis of the elastic constants showed that ductility of FeAl alloys was improved by the addition of V, Cr or Ni, the improvement was the highest when Cr was used. The order of the ductility was as follows: Fe8CrAl7 > Fe8NiAl7 > Fe8VAl7 > Fe8Al8. The results of electronic structure analysis showed that FeAl were brittle, mainly due to the orbital hybridization of the s, p and d state electron of Fe and the s and p state electrons of Al, showing typical characteristics of a valence bond. Micro-mechanism for improving ductility of FeAl is that d orbital electron of alloying element is maily involved in hybridization of FeAl, alloying element V, Cr and Ni decrease the directional property in bonding of FeAl.


2013 ◽  
Vol 347-350 ◽  
pp. 1132-1138 ◽  
Author(s):  
Hai Dong Wang ◽  
Xu Liu ◽  
Gui Xue Bian ◽  
Li Xu ◽  
Shi Zhao

Elastic constants of purity and containing impurity metal aluminum were calculated, and the effects of impurity on the elastic constants were also studied. The effect of particle on micro-stress concentration and debonded stress of inclusion was researched. The mechanical relationship between the grains was defined by relationship of displacement and driving force in cohesion zone model (CZM).The method can be extended to research mechanical properties of other metals and alloys structures.


Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2010
Author(s):  
Shuo Wang ◽  
Yuhong Zhao ◽  
Huijun Guo ◽  
Feifei Lan ◽  
Hua Hou

In this paper, the mechanical properties and minimum thermal conductivity of ZnZr, Zn2Zr, Zn2Zr3, and MgZn2 are calculated from first principles. The results show that the considered Zn-Zr intermetallic compounds are effective strengthening phases compared to MgZn2 based on the calculated elastic constants and polycrystalline bulk modulus B, shear modulus G, and Young’s modulus E. Meanwhile, the strong Zn-Zr ionic bondings in ZnZr, Zn2Zr, and Zn2Zr3 alloys lead to the characteristics of a higher modulus but lower ductility than the MgZn2 alloy. The minimum thermal conductivity of ZnZr, Zn2Zr, Zn2Zr3, and MgZn2 is 0.48, 0.67, 0.68, and 0.49 W m−1 K−1, respectively, indicating that the thermal conductivity of the Mg-Zn-Zr alloy could be improved as the precipitation of Zn atoms from the α-Mg matrix to form the considered Zn-Zr binary alloys. Based on the analysis of the directional dependence of the minimum thermal conductivity, the minimum thermal conductivity in the direction of [110] can be identified as a crucial short limit for the considered Zn-Zr intermetallic compounds in Mg-Zn-Zr alloys.


Author(s):  
Ahmad A. Mousa ◽  
Jamil M. Khalifeh

Structural, electronic, elastic and mechanical properties of ScM (M[Formula: see text][Formula: see text][Formula: see text]Au, Hg and Tl) intermetallic compounds are studied using the full potential-linearized augmented plane wave (FP-LAPW) method based on the density functional theory (DFT), within the generalized gradient approximation (GGA) and the local density approximation (LDA) to the exchange-correlation approximation energy as implemented in the Wien2k code. The ground state properties including lattice parameters, bulk modulus and elastic constants were all computed and compared with the available previous theoretical and experimental results. The lattice constant was found to increase in contrast to the bulk modulus which was found to decrease with every substitution of the cation (M) starting from Au till Tl in ScM. Both the electronic band structure and density-of-states (DOS) calculations show that these compounds possess metallic properties. The calculated elastic constants ([Formula: see text], [Formula: see text] and [Formula: see text] confirmed the elastic stability of the ScM compounds in the B2-phase. The mechanical properties and ductile behaviors of these compounds are also predicted based on the calculated elastic constants.


2020 ◽  
Vol 12 ◽  
pp. 42-52
Author(s):  
S. A. Muslov ◽  
◽  
A. I. Lotkov ◽  
S. D. Arutyunov ◽  
T. M. Albakova ◽  
...  

A review of studies of the mechanical properties of human and animal heart tissues has been performed. Based on literature data, a form of approximating function is found for the dependence of the Young’s modulus of the ventricles of the human heart on the magnitude of the deformation. The average values of the Young’s modulus and other elastic constants were calculated and compared with the known experimental values. The coefficients C1 and C2 of the two-parameter hyperelastic myocardial Mooney-Rivlin model are calculated.


RSC Advances ◽  
2020 ◽  
Vol 10 (24) ◽  
pp. 14080-14088 ◽  
Author(s):  
Yu Liu ◽  
Kai Wang ◽  
Hui Xiao ◽  
Gang Chen ◽  
Zhipeng Wang ◽  
...  

There is a dramatic change of the elastic constants when Mo content increases from 0.26 to 0.28, indicating that the deformation resistance of CrFeCoNiMox (0.26 ≤ x ≤ 0.28) HEAs has changed greatly.


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