Bridging the multi phase-field and molecular dynamics models for the solidification of nano-crystals

摘要

We present a computational analysis of the multi-grain solidification behavior of a crystal -melt nickel (Ni) system at a moderate undercooling degree via both a molecular dynamics (MD) and a phase field model (PFM). The required simulation parameters for the PFM analysis are extracted from the MD analysis employing embedded atom (EAM) potentials thus leveraging the dual approach. The good agreement of the solidification dynamics as predicted by both the PFM and MD approaches at the nano-temporal and spatial length scales, indicates the feasibility of bridging the MD and PFM simulations in the statistical mean sense. This is achieved by parameterizing the PFM by materials properties obtained from MD and by characterizing the contribution of individual physical quantities through the PFM approach. Throughout this approach, we can more closely relate MD and PFM analysis, which can potentially enable better predictions of the themodynamic and kinetic processes of solidification, melting, and phase transformation processes with the PFM approach when is based on MD simulations. (C) 2016 Elsevier B.V. All rights reserved.