Understanding the volume-diffusion governed shape-instabilities in metallic systems

TL;DR

This paper employs phase-field modeling to analyze the stability and shape instabilities of microstructures in metallic systems driven by volume diffusion, providing insights into curvature-induced transformations without interface tracking complexities.

Contribution

It demonstrates that phase-field modeling can accurately recover the Gibbs-Thomson relation and effectively analyze microstructure stability in metals.

Findings

Phase-field model recovers Gibbs-Thomson law.

Analyzes curvature-driven microstructure evolution.

Provides a numerical framework for stability assessment.

Abstract

The reliability of any day-to-day material is critically dictated by its properties. One factor which governs the behaviour of a material, under a given condition, is the microstructure. Despite the absence of any phase transformation, a change in the microstructure would significantly alter the properties. Therefore, a substantial understanding on the stability of the microstructure is vital to avert any unexpected catastrophic change in the material properties. In the present work, one such numerical approach called phase-field modelling in employed to analyse the stability of two- and three-dimensional finite structures, which dictate the curvature-driven evolution of the microstructure. A characteristic feature of this numerical approach is the introduction of a scalar variable, called the phase field, in addition to the other thermodynamic variables. While the inclusion of the phase field obviates the need for the interface tracking, which is a strenuous aspect of the other conventional techniques, it replaces the sharp interface with a finite diffuse region. Therefore, before adopting and extending the phase-field technique, it is shown that the model recovers the governing law, i.e, Gibbs-Thomson relation, despite the introduction of the diffuse interface. Subsequently, the numerical treatment is employed to investigate the volume-diffusion governed curvature-induced transformation.