Response embedded atom model potential of Pb at finite temperature: application on the dislocation mobility

Li, Pan; Huang, Yongfeng; Wang, Kun; Xiao, Shifang; Yao, Songlin; Hu, Wangyu

doi:10.1088/1402-4896/acaeec

Cited by 2 publications

(3 citation statements)

References 74 publications

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“…Thereby, the dislocation moves through the motion of the two partial dislocations and the stacking fault between them. Due to the influence of internal stress fluctuation and external obstacles during the glide process, the stacking fault width will fluctuate [37]. If the applied stress is large enough, the width could change significantly, which will affect the dislocation glide velocity.…”

Section: Mobility Of the Edge Dislocation Under Different Vacancy Con...mentioning

confidence: 99%

“…In addition, the slope of the dislocation position curve tends to be stable after 100 ps. As velocity is defined as the derivative of displacement with respect to time, it can be estimated using the slope of the displacement versus time curve of the dislocation after 100 ps when the dislocation motion is stable [37]. When the applied stress is in the range of 10-300 MPa, the position of edge dislocation for C v = 0% is positively correlated with time.…”

Section: Mobility Of the Edge Dislocation Under Different Vacancy Con...mentioning

confidence: 99%

“…In addition, elastic property is believed to be crucial for the dislocation motion [37] since it determines the velocity limit that the dislocation could reach in a crystal. The elastic constants as a function of the vacancy concentration are calculated using the finite deformation method.…”

Section: Physical Understanding Of the Role Played By The Nonequilibr...mentioning

confidence: 99%

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Effects of vacancy concentration on the edge dislocation motion in copper by atomic simulations

Chen,

Li,

Yao

et al. 2023

Modelling Simul. Mater. Sci. Eng.

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Nonequilibirum vacancy concentration widely appears in crystals under many extreme loading conditions, but receives relatively few attentions. In this work, we systematically explore the influence of a serial of different vacancy concentrations on the edge dislocation motion in copper using molecular dynamics (MD) simulations. Our result shows that the vacancy would hinder the dislocation motion, but the mechanism depends on the detailed dislocation motion regions. In thermally activated region, its influence is mainly reflected by modifying the dynamic and static threshold stresses required for edge dislocation initiation and continuous motion. In the linear region, the hindering mechanism is gradually transformed from phonon damping to vacancy pinning with the increasing vacancy concentration. In contrasts, the dislocation structure is almost unchanged under different vacancy concentrations in the non-linear region. Under high applied stress, high vacancy concentration will cause the dislocation velocity to jump back and forth between transonic and subsonic velocities more frequently. It has been attributed to the reactions between the dislocation and vacancies. The latter may result in dislocation local constriction and climbing. Moreover, a mobility equation suitable for describing edge dislocations at different non-equilibrium vacancy concentrations is proposed, which fits the MD results well. Finally, the roles of the nonequilibirum vacancy concentration on the edge dislocation motion is interpreted using the degrading elastic property and stacking fault energy.

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Section: Mobility Of the Edge Dislocation Under Different Vacancy Con...mentioning

confidence: 99%

Section: Mobility Of the Edge Dislocation Under Different Vacancy Con...mentioning

confidence: 99%

See 1 more Smart Citation

Effects of vacancy concentration on the edge dislocation motion in copper by atomic simulations

Chen,

Li,

Yao

et al. 2023

Modelling Simul. Mater. Sci. Eng.

Self Cite

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On the grain size effects of the spallation in Pb by quasi-coarse-grained molecular dynamics

Wang,

Li,

Gao

et al. 2024

Journal of Applied Physics

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FCC-HCP phase transition plays a pivotal role in many intelligent materials, which also occurs in Pb under high pressures. However, its impacts on the spallation of polycrystalline, as well as the effects related to grain size, are still unclear. In this work, spallation behaviors of Pb polycrystals with different grain sizes under various shock loadings are investigated using the quasi-coarse-grained molecular dynamics (QCGD) method based on our recently developed response embedding atom model potential. The QCGD method is rigorously validated for applications in the metals exhibiting solid–solid phase transitions. Due to the restriction of the critical size for the phase transition nucleus, the coarsening level of the QCGD method cannot exceed two times the lattice parameter. Nevertheless, such a method enables us to explore the whole rule of the grain-size-dependence incipient spall strength. Our results suggest that the incipient spall strength exhibits a transition from the Hall–Petch to the inverse Hall–Petch relationship at about 13 nm and the spallation strength converging to that of a single crystal for grain sizes larger than 60 nm. As the grain size decreases, void nucleation becomes more prevalent than void growth, making the material better equipped to prevent the progression of damage into fractures. When the grain size is sufficiently large, voids nucleate and grow in the grain interior, making the spallation behave like in a single crystal. Interestingly, the phase transition from HCP to FCC phase enhances dislocation entanglement, leading to heterogeneous nucleation of voids in the grain interior.

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Response embedded atom model potential of Pb at finite temperature: application on the dislocation mobility

Cited by 2 publications

References 74 publications

Effects of vacancy concentration on the edge dislocation motion in copper by atomic simulations

Effects of vacancy concentration on the edge dislocation motion in copper by atomic simulations

On the grain size effects of the spallation in Pb by quasi-coarse-grained molecular dynamics

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