Room Temperature Deformation-induced Solute Segregation and its Impact on Twin Boundary Mobility in a Mg-Y Alloy

Mechanical behavior of alloys is influenced by segregation of solute atoms, which affects deformation mechanisms, such as slip and twinning. In this study, we report on an atomic-scale investigation into room temperature, deformation-induced solute segregation in a Mg-Y alloy. High concentrations of Y were observed at the dislocation cores. In addition, we found that {10 (1) over bar2} twins were bounded by coher-ent twin boundaries and basal-prismatic facets, which contained periodic segregation of Y-rich columns and nano-sized Y-rich clusters, respectively. The observed segregation arrangement was energetically at-tributed to the fact that it minimizes the overall lattice distortion and is kinetically assisted by the dy-namic interaction between solute atoms and crystallographic defects and the slip-twin interaction during plastic deformation. Moreover, segregated Y atoms exert a pinning effect and lead to anisotropy on the mobility of twin boundaries. This finding offers a potentially new alloy design path to control the me-chanical response of Mg alloys. (C) 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Automated summary

The study investigates deformation-induced solute segregation in a Mg-Y alloy at room temperature. High concentrations of Y were observed at dislocation cores, and the segregation arrangement minimizes lattice distortion and is supported kinetically by dynamic interactions between solute atoms, crystallographic defects, and slip-twin interactions during plastic deformation.