A thermodynamic and analytical description on the quantitative phase-field model with enhanced interface diffusivity

TL;DR

This paper introduces a thermodynamic and analytical approach to enhance interfacial diffusivity in phase-field models, maintaining key thermodynamic quantities and enabling accurate simulations of complex alloy systems.

Contribution

It provides a new method to determine interfacial diffusivity enhancement without numerical corrections, applicable to arbitrary thermodynamic properties and multicomponent systems.

Findings

The method preserves thermodynamic quantities after interface width enlargement.

It is applicable to binary alloys with arbitrary thermodynamic properties.

The approach advances quantitative phase-field modeling for practical applications.

Abstract

Based on the idea of maintaining physical diffuse interface kinetics, enhancing interfacial diffusivity has recently provided a new direction for quantitative phase-field simulation at microstructural length and time scale. Establishing a general relationship between interface diffusivity and width is vital to facilitate the practical application. However, it is still limited by time-consuming numerical corrections, and its relationship with non-dilute thermodynamic properties still needs to be revealed. In this study, we present a new thermodynamic and analytical method for determining interfacial diffusivity enhancement. Unlike previous numerical corrections of partition coefficients and interface temperature, this new method aims to keep several thermodynamic quantities unchanged after enlarging the interface width. These essential quantities are theoretically proven to be diffusion potential jump across the diffuse interface and free energy dissipation by trans-interface diffusion. Since no dilute approximation has been employed in model derivation, the present method is available for binary alloys with arbitrary thermodynamic properties and can be easily extended to describe multicomponent systems. Therefore, the present method is expected to advance the recent quantitative phase-field framework and facilitate its practical applications.