Abstract
While the crystal–melt interface kinetic equation predicts various kinetic behaviors, the realization of these scenarios and the corresponding thermodynamic conditions remain unclear. In this work, six representative interface kinetic behaviors of Fe were modeled and examined by molecular dynamics simulations. For the flat interface, several models were designed to study the migration, fluctuation, and recovery of the interface. For the cylindrical or curved interface, different models were also designed to test the equilibrium, migration, and instability of the interface. By comparing the kinetic behaviors of the two types of interfaces, we can observe the effect of interface curvature. During the simulations, two crucial material-specific parameters, the crystal–melt interface free energy and kinetic coefficient, were determined and compared among different models.
Highlights
Microstructural features, such as phases, grains, dislocation networks and twins, and so on, determine the properties of metals
There are two physical quantities: the melting point TM and the latent heat of melting ΔH appearing in Eq (1), which must be determined before studying the interface kinetic behavior
We performed simulations on pure Fe using an embedded atom method (EAM) potential developed by Mendelev et al.15 and referred to as MH(SA)2.16–18 Compared to its many counterparts, MH(SA)2 is in better agreement with the experimental or first-principles calculated lattice parameter, elastic constants, pointdefect energies, bcc-fcc transformation energy, liquid density, liquid structure factor, melting temperature, and other properties
Summary
Microstructural features, such as phases, grains, dislocation networks and twins, and so on, determine the properties of metals. A remaining obstacle in the application of PFM in real systems is the specification of material-specific parameters, which are difficult to be measured experimentally nor theoretically via ab initio calculations Among these parameters are two important ones: the crystal–melt interface free energy (γ) and the kinetic coefficient (μ) (which is the proportionality constant between the normal velocity of the interface motion and the undercooling temperature). The paper is organized as follows: In Sec. II, we describe how we determine the melting point and the latent heat of melting, which are needed in this paper to calculate other thermodynamic and kinetic properties.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
