# Effect of elastic anisotropy on phase separation in ternary alloys: A phase-field study

## TL;DR

This study uses a phase-field model to explore how elastic anisotropy influences microstructural evolution and phase separation in ternary alloys, revealing its critical role in precipitate morphology and alignment.

## Contribution

It introduces a phase-field approach incorporating elastic anisotropy to analyze microstructure development in ternary alloys, highlighting the impact of elastic moduli anisotropy on precipitate morphology.

## Key findings

- Elastic anisotropy affects precipitate shape and alignment.
- Misfit strains influence phase equilibria and pathways.
- Elastic moduli anisotropy determines inclusion morphology.

## Abstract

The precipitate shape, size and distribution are crucial factors which determine the properties of several technologically important alloys. Elastic interactions between the inclusions modify their morphology and align them along elastically favourable crystallographic directions. Among the several factors contributing to the elastic interaction energy between precipitating phases, anisotropy in elastic moduli is decisive in the emergence of modulated structures during phase separation in elastically coherent alloy systems. We employ a phase-field model incorporating elastic interaction energy between the misfitting phases to study microstructural evolution in ternary three-phase alloy systems when the elastic moduli are anisotropic. The spatiotemporal evolution of the composition field variables is governed by solving a set of coupled Cahn-Hilliard equations numerically using a semi-implicit Fourier spectral technique. We methodically vary the misfit strains, alloy chemistry and elastic anisotropy to investigate their influence on domain morphology during phase separation. The coherency strains between the phases and alloy composition alter the coherent phase equilibria and decomposition pathways. The degree of anisotropy in elastic moduli modifies the elastic interaction energy between the precipitates depending on the sign and magnitude of relative misfits, and thus determines the shape and alignment of the inclusions in the microstructure.