Grain boundary solute segregation across the 5D space of crystallographic character

TL;DR

This study systematically analyzes how Co solute atoms segregate across a wide range of grain boundary types in aluminum, revealing complex patterns influenced by crystallographic features and validating the findings with multiple simulation methods.

Contribution

It provides the first comprehensive 5D crystallographic characterization of solute segregation in Al grain boundaries, enhancing understanding of segregation behavior across diverse GB types.

Findings

Co exhibits strong segregation to Al GBs

Segregation correlates with GB energy and excess volume

Segregation landscape is complex and varies smoothly in 5D space

Abstract

Solute segregation in materials with grain boundaries (GBs) has emerged as a popular method to thermodynamically stabilize nanocrystalline structures. However, the impact of varied GB crystallographic character on solute segregation has never been thoroughly examined. This work examines Co solute segregation in a dataset of 7272 Al bicrystal GBs that span the 5D space of GB crystallographic character. Considerable attention is paid to verification of the calculations in the diverse and large set of GBs. In addition, the results of this work are favorably validated against similar bicrystal and polycrystal simulations. As with other work, we show that Co atoms exhibit strong segregation to sites in Al GBs and that segregation correlates strongly with GB energy and GB excess volume. Segregation varies smoothly in the 5D crystallographic space but has a complex landscape without an obvious functional form.