Atomistic Assessment of Solute-Solute Interactions during Grain Boundary Segregation

Round 1

Reviewer 1 Report

Grain boundary segregation is an efficient routine to stabilize nanocrystalline alloys. The present manuscript reports a physically motived approach to determine the full distribution of solute-solute interaction energies for grain boundary segregation in polycrystalline materials. The thermodynamic model is tested with the Al-Mg alloy system. It turns out that the solute-solute interaction energies in the Al-Mg system roughly exhibit a typical skew-normal distribution. Furthermore, the authors managed to establish a full bivariate normal distribution which can describe the grain boundary segregation beyond the dilute limit. Such distribution of site and interaction energies can powerfully predict the solute distribution in equilibrium, the results of which are in excellent agreement with the prediction by hybrid Monte Carlo/Molecular Statics simulations. The present work which provides a methodology for rapidly determining the solute-solute interactions for non-dilute grain boundary segregation is considered important for investigating grain boundary segregations. In addition, the manuscript is written concisely and comprehensively, and the results are sufficiently novel. Given the above, an acceptance without revision is strongly suggested.

Reviewer 2 Report

The paper brings interesting results regarding the
atomistic approaches to solute-solute interactions 
during grain boundary segregation. It is written concisely 
and comprehensively and the results are sufficiently novel 
and of broad interest to warrant the publication in 
Nanomaterials. In particular, the paper presents the
first atomistic characterization of the full spectrum 
of solute-solute interaction energies at the GB in
Al-Mg system. I recommend its publication in the present form.