Computational study of atomic mobility in HCP Mg-Al-Zn ternary alloys

TL;DR

This study critically reviews and re-analyzes experimental diffusion data in the Mg-Al-Zn hcp alloy system, developing an atomic mobility database that accurately reproduces diffusion behavior through computational modeling.

Contribution

It introduces a new atomic mobility database for Mg-Al-Zn alloys based on re-analyzed experimental data and thermodynamic modeling, improving predictive accuracy.

Findings

Excellent agreement between calculated and experimental diffusion data

Validated the atomic mobility database with diffusion profiles

Enhanced understanding of atomic mobility in Mg-Al-Zn alloys

Abstract

The experimental data in the literature for the hcp phase of the Mg-Al-Zn ternary system have been critically reviewed. Based on the concentration profiles from the literature, the diffusion coefficients have been re-extracted using the Hall method for the impurity diffusion, and the Sauer-Freise and the Whittle-Green strategies for interdiffusion coefficients in binary and ternary systems, respectively. Moreover, extra interdiffusion coefficients were obtained from the Darken-type couples, which present relative maxima or/and minima at the concentration profiles. This information was assessed to obtain an atomic mobility database, by means of DICTRA software in conjunction with the CALPHAD thermodynamic description that is able to reproduce the diffusion couple experiments. Comprehensive comparisons between the calculated results and experimental values show an excellent agreement not only for the diffusion coefficient data, but also for the concentration profiles and the diffusion paths.