The effect of dislocations on the thermodynamic properties of Ta single crystal under high pressure by molecular dynamics simulation

Li, Yalin; Cai, Jihua; Mo, Dan; Wang, Yandong

doi:10.1088/1674-1056/27/8/086401

Cited by 3 publications

(3 citation statements)

References 35 publications

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“…Furthermore, it cannot be ignored that the discontinuities in the variation of elastic constants with pressure is another evidence of the instability of a crystal [34][35][36]. For ZrN, as shown in figure 6(a), the curves of elastic constants and moduli versus pressure seem to be continuous and smooth.…”

Section: Elastic Properties Wave Velocities and Debye Temper Aturementioning

confidence: 99%

First principle study on the predicted phase transition of MN (M = Zr, La and Th)

Wang

2019

J. Phys.: Condens. Matter

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First principle (FP) calculations were performed to systematically study the structural properties of ZrN, LaN and ThN with GGA correction. The ground state properties, wave velocities and Debye temperature of B1, P6 3 /mmc, Pnma and B2 phase in ZrN, LaN and ThN were investigated and agree well with other theoretical and experimental results. More importantly, some novel phases are predicted in these materials, i.e. with the increasing pressure the phase transition sequence in ZrN and ThN is found to be B1 → P6 3 /mmc → B2 phase, while in LaN, the sequence of B1 → Pnma → B2 is observed. Furthermore, our calculated elastic properties also confirm the prediction of phase transition under high pressure. These phase transitions arise from the optical phonon softening of B1 at around X, M and G points of Brillouin zone and P6 3 /mmc (or Pnma) structure at around G, and H-K points.

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Section: Elastic Properties Wave Velocities and Debye Temper Aturementioning

confidence: 99%

First principle study on the predicted phase transition of MN (M = Zr, La and Th)

Wang

2019

J. Phys.: Condens. Matter

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“…The results obtained in this article are similar to those in refs. [53][54][55][56][57]. The change curves of S 11 , S 12 , and S 44 with pressure are shown in Figure 10.…”

Section: The Changes Of Elastic Modulus and Shear Modulus With Pressumentioning

confidence: 99%

Effects of Temperature and Pressure on Elastic Properties of Single Crystal Aluminum in Different Crystal Orientations

Yang

2020

Physica Status Solidi (b)

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Molecular dynamics simulations are carried out to study the mechanical and elastic properties of single crystal aluminum with various crystal orientations at different temperatures and under different pressure. Transformations of lattice structures under high pressure, tensile and shearing loads are investigated, respectively. When the pressure increases to 1011 Pa, the face centered cubic (FCC) structure is completely transformed into body centered cubic (BCC) and other structures. The transformation from FCC to hexagonal close packed (HCP) and other structures takes place during tensile and shearing processes. Elastic compliance constants are calculated at different temperatures. Elastic modulus and shear modulus of different crystal orientations at different temperatures are calculated by the formula method, and compared with the results of molecular dynamics method. The decrease extent of elastic modulus in <111> crystal orientation is the smallest with the increase of temperature. The effects of high pressure on elastic modulus and shear modulus in different crystal orientations are also investigated. When the pressure exceeds 109 Pa, the elastic modulus and shear modulus in all crystal orientations begin to increase. Poisson's ratio in different crystal orientations at different temperatures and under high pressure are also calculated.

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“…In this work, the effect of crystal orientations and loading conditions on the deformation behaviors of HCP-Ti is investigated using MD simulations, which has been used widely to explain the mechanical behavior and detailed deformation process of materials. [23][24][25][26][27][28] The results show that the deformation behavior strongly depends on orientation and loading mode. This work will provide a new sight in the orientation-dominated plastic deformation mechanism.…”

Section: Introductionmentioning

confidence: 95%

Anisotropic plasticity of nanocrystalline Ti: A molecular dynamics simulation*

Deng

et al. 2020

Chinese Phys. B

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Using molecular dynamics simulations, the plastic deformation behavior of nanocrytalline Ti has been investigated under tension and compression normal to the {0001}, { 1 ¯ 010 } , and { 1 ¯ 2 1 ¯ 0 } planes. The results indicate that the plastic deformation strongly depends on crystal orientation and loading directions. Under tension normal to basal plane, the deformation mechanism is mainly the grain reorientation and the subsequent deformation twinning. Under compression, the transformation of hexagonal-close packed (HCP)-Ti to face-centered cubic (FCC)-Ti dominates the deformation. When loading is normal to the prismatic planes (both { 1 ¯ 010 } and { 1 ¯ 2 1 ¯ 0 } ), the deformation mechanism is primarily the phase transformation among HCP, body-centered cubic (BCC), and FCC structures, regardless of loading mode. The orientation relations (OR) of {0001}HCP║{111}FCC and 〈 1 ¯ 210 〉 HCP | | 〈 110 〉 FCC , and { 10 1 ¯ 0 } HCP | | { 1 1 ¯ 0 } FCC and 〈 0001 〉 HCP | | 〈 010 〉 FCC between the HCP and FCC phases have been observed in the present work. For the transformation of HCP → BCC → HCP, the OR is 0001 α 1 | | { 110 } β | | { 10 1 ¯ 0 } α 2 (HCP phase before the critical strain is defined as α 1-Ti, BCC phase is defined as β-Ti, and the HCP phase after the critical strain is defined as α 2-Ti). Energy evolution during the various loading processes further shows the plastic anisotropy of nanocrystalline Ti is determined by the stacking order of the atoms. The results in the present work will promote the in-depth study of the plastic deformation mechanism of HCP materials.

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The effect of dislocations on the thermodynamic properties of Ta single crystal under high pressure by molecular dynamics simulation

Cited by 3 publications

References 35 publications

First principle study on the predicted phase transition of MN (M = Zr, La and Th)

First principle study on the predicted phase transition of MN (M = Zr, La and Th)

Effects of Temperature and Pressure on Elastic Properties of Single Crystal Aluminum in Different Crystal Orientations

Anisotropic plasticity of nanocrystalline Ti: A molecular dynamics simulation*

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