A Phase Field Crystal Study of Solute Trapping

TL;DR

This paper extends the phase field crystal model for binary alloys by incorporating two time scales, revealing different solute trapping behaviors depending on interface velocity and dynamics type.

Contribution

It introduces a dual-time-scale phase field crystal model that captures solute trapping phenomena with diffusive and wave-like dynamics, aligning with different theoretical models.

Findings

Diffusive dynamics show K approaches 1 at high velocity, consistent with Kaplan and Aziz.

Wave-like dynamics lead to complete trapping at finite velocity, matching Sobolev's kinetics.

Model bridges diffusive and wave dynamics in solute trapping phenomena.

Abstract

In this study we have incorporated two time scales into the phase field crystal model of a binary alloy to explore different solute trapping properties as a function of crystal-melt interface velocity. With only diffusive dynamics, we demonstrate that the segregation coefficient, K as a function of velocity for a binary alloy is consistent with the model of Kaplan and Aziz where K approaches unity in the limit of infinite velocity. However, with the introduction of wave like dynamics in both the density and concentration fields, the trapping follows the kinetics proposed by S. Sobolev[Phys. Rev. A. 199:383386, 1995.], where complete trapping occurs at a finite velocity.