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

摘要

The experimental data in the literature for the hcp phase of the Mg-Al-Znternary system have been critically reviewed. Based on the concentrationprofiles from the literature, the diffusion coefficients have been re-extractedusing the Hall method for the impurity diffusion, and the Sauer-Freise and theWhittle-Green strategies for interdiffusion coefficients in binary and ternarysystems, respectively. Moreover, extra interdiffusion coefficients wereobtained from the Darken-type couples, which present relative maxima or/andminima at the concentration profiles. This information was assessed to obtainan atomic mobility database, by means of DICTRA software in conjunction withthe CALPHAD thermodynamic description that is able to reproduce the diffusioncouple experiments. Comprehensive comparisons between the calculated resultsand experimental values show an excellent agreement not only for the diffusioncoefficient data, but also for the concentration profiles and the diffusionpaths.