Crystal-melt interface mobility in bcc Fe: Linking molecular dynamics to phase-field and phase-field crystal modeling

Guerdane, M.; Berghoff, Marco

doi:10.1103/physrevb.97.144105

Cited by 21 publications

(14 citation statements)

References 27 publications

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“…It has been shown [25] that the traditional kinetic theories, such as CLT and DLT, as well as the phase-field models (PFMs) based on local thermodynamic equilibrium [26], often fail to quantitatively describe the nonlinear behaviour in the crystal growth velocity predicted in MD simulations. While the local equilibrium PFMs can describe the nonlinear dependence of the interface velocity predicted in MD simulations in a relatively narrow temperature range [27], the extension of this description to a wider range of undercoolings, where the velocity goes through the maximum and slows down with increasing undercooling [2,[7][8][9][10][11][12][13][14][15][16], still presents a challenge.…”

Section: Introductionmentioning

confidence: 99%

Kinetics of solid–liquid interface motion in molecular dynamics and phase-field models: crystallization of chromium and silicon

Karim

Salhoumi

et al. 2021

Phil. Trans. R. Soc. A.

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The results of molecular dynamics (MD) simulations of the crystallization process in one-component materials and solid solution alloys reveal a complex temperature dependence of the velocity of the crystal–liquid interface featuring an increase up to a maximum at 10–30% undercooling below the equilibrium melting temperature followed by a gradual decrease of the velocity at deeper levels of undercooling. At the qualitative level, such non-monotonous behaviour of the crystallization front velocity is consistent with the diffusion-controlled crystallization process described by the Wilson–Frenkel model, where the almost linear increase of the interface velocity in the vicinity of melting temperature is defined by the growth of the thermodynamic driving force for the phase transformation, while the decrease in atomic mobility with further increase of the undercooling drives the velocity through the maximum and into a gradual decrease at lower temperatures. At the quantitative level, however, the diffusional model fails to describe the results of MD simulations in the whole range of temperatures with a single set of parameters for some of the model materials. The limited ability of the existing theoretical models to adequately describe the MD results is illustrated in the present work for two materials, chromium and silicon. It is also demonstrated that the MD results can be well described by the solution following from the hodograph equation, previously found from the kinetic phase-field model (kinetic PFM) in the sharp interface limit. The ability of the hodograph equation to describe the predictions of MD simulation in the whole range of temperatures is related to the introduction of slow (phase field) and fast (gradient flow) variables into the original kinetic PFM from which the hodograph equation is obtained. The slow phase-field variable is responsible for the description of data at small undercoolings and the fast gradient flow variable accounts for local non-equilibrium effects at high undercoolings. The introduction of these two types of variables makes the solution of the hodograph equation sufficiently flexible for a reliable description of all nonlinearities of the kinetic curves predicted in MD simulations of Cr and Si. This article is part of the theme issue ‘Transport phenomena in complex systems (part 1)’.

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Section: Introductionmentioning

confidence: 99%

Kinetics of solid–liquid interface motion in molecular dynamics and phase-field models: crystallization of chromium and silicon

Karim

Salhoumi

et al. 2021

Phil. Trans. R. Soc. A.

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“…Since the anisotropy in the kinetic coefficient directly affects the morphology of the solidification microstructure, 82,83) it is essential to estimate the kinetic coefficient including its anisotropy. In an MD simulation, the kinetic coefficient is usually estimated from the temperature dependence of the propagation velocity of the planar solid-liquid interface in a biphasic system.…”

Section: Kinetic Coefficient Of Solid-liquid Interfacementioning

confidence: 99%

Estimation of Thermodynamic and Interfacial Parameters of Metallic Materials by Molecular Dynamics Simulations

Shibuta

2019

Mater. Trans.

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The range of application of molecular dynamics (MD) simulations is rapidly expanding owing to the recent advance in high-performance computing. Since only the coordinate and velocity of atoms in the system are directly obtained from MD simulations, it is important to correctly understand how the coordinate and velocity of atoms are converted into thermodynamic and interfacial properties. Here, MD-based techniques for estimating the thermodynamic and interfacial properties of metallic materials are assessed by considering practical examples of the melting point of a pure metal, the solidus and liquidus compositions of a binary alloy, the grain boundary energy, the solid-liquid energy, and the kinetic coefficient. [

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“…14 These simulations and the analyzed patterns have been obtained for equilibrium phase coexistence as well as for first-and second-order phase transformations. 3,[15][16][17][18][19] Using the MPFC model, the present work attempts to describe transitions of the first and second order by special analytical transformation. Such unified description is developed in examples of the homogeneous part of free energy density given by Landau-de-Gennes form (as a typical energetic representation of the first-order transitions) and by Swift-Hohenberg form (as a simplest energetic representation of the second-order transitions).…”

Section: Introductionmentioning

confidence: 99%

About one unified description of the first‐ and second‐order phase transitions in the phase‐field crystal model

Ankudinov

Starodumov

Galenko

2020

Math Methods in App Sciences

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Modeling of crystal micro-structures and their dynamics during fast phase transitions can be performed by the phase-field crystal (PFC) model in the hyperbolic formulation (Modified Phase Field Crystal [MPFC] model). This method is suitable for a continual modeling of the atomic density field at diffusion time intervals (slow diffusion dynamics) and short intervals of atomic flux relaxation (fast structural relaxation). Since the PFC model describes transitions of the first and second order, we present a description of both transitions in a unified manner. We show how phase transitions of each order can be treated using specific analytical transformations. To justify the unified approach to description of the first-and second-order transformations, we provide results of numerical simulation of phase changes between homogeneous structure and Body Centered Cubic (BCC) crystal lattice. The set of benchmarks for different domains shows coincidence of instantaneous atomic distributions and free energies in both forms.

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Crystal-melt interface mobility in bcc Fe: Linking molecular dynamics to phase-field and phase-field crystal modeling

Cited by 21 publications

References 27 publications

Kinetics of solid–liquid interface motion in molecular dynamics and phase-field models: crystallization of chromium and silicon

Kinetics of solid–liquid interface motion in molecular dynamics and phase-field models: crystallization of chromium and silicon

Estimation of Thermodynamic and Interfacial Parameters of Metallic Materials by Molecular Dynamics Simulations

About one unified description of the first‐ and second‐order phase transitions in the phase‐field crystal model

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