Variational quantitative phase-field modeling of nonisothermal sintering process

TL;DR

This paper introduces a variational phase-field model for non-isothermal sintering, incorporating cross-coupling effects and anisotropic mobility to improve the accuracy of thermal and microstructural evolution predictions.

Contribution

It develops a novel variational, quantitative phase-field model with cross-coupling terms and anisotropic interpolation for non-isothermal sintering, ensuring thermodynamic consistency.

Findings

Cross-coupling terms eliminate interface artifacts.

Anisotropic mobility improves modeling of surface diffusion.

Model accurately predicts thermal and microstructural evolution.

Abstract

In this work, we present a variational and quantitative phase-field model for non-isothermal sintering processes. The model is derived via an extended non-diagonal phase-field model. The model evolution equations have naturally cross-coupling terms between the conserved kinetics (i.e., mass and thermal transfer) and the non-conserved one (grain growth). These terms are shown via asymptotic analysis to be instrumental in ensuring the elimination of interface artefacts, while also examined to not modify the thermodynamic equilibrium condition (characterized by dihedral angle). Moreover, we demonstrate that the trapping effects and existence of surface diffusion in conservation laws are direction-dependent. An anisotropic interpolation scheme of the kinetic mobilities which differentiates the normal and the tangential directions along the interface is discussed. Numerically, we demonstrate the importance of the cross-couplings and the anisotropic interpolation via presenting thermal-microstructural evolutions.