Atomistic simulations of the interaction of alloying elements with grain boundaries in Mg

Publication Type
Journal Article
Year of Publication
2014
Authors
Huber, Liam
Rottler, Jörg
Militzer, Matthias
Name of Publication
Acta Materialia
Volume
80
Pagination
194–204
ISSN
1359-6454
Keywords
Atomistic modeling, Grain boundary, Magnesium, Rare earth
Abstract

Quantum density functional theory ({DFT}) is used to compute binding energies of important alloying elements (Ag, Zn, Ti, Al, Cd, Zr, Y, Ca, Nd, Ce and La) to a Σ 7 grain boundary ({GB}) in Mg. In particular, quantifying the interaction of rare earth ({RE}) elements with Mg {GBs} is of significance given the strong effect of these solutes on modifying the texture of Mg alloys. For most alloying elements studied, the binding energy scales with the size of the solute and the local {GB} site volumes. Based on these trends, a model for the solute–{GB} binding energy is developed which accurately captures the behavior of the technologically important {RE} solutes and Ca. This model is then employed in conjunction with molecular statics calculations to predict solute segregation to general {GBs} not accessible by {DFT}. The predicted trends are found to be in qualitative agreement with available experimental data for {GB} segregation in Mg.