Origin Of Twin-Like {33(3)Over-Bar4} Tilt Boundary And Associated Solute Segregation In A High Strain Rate Deformed Mg-Y Alloy

A high strain rate compressed Mg-Y alloy is prepared for the study of 1 1 over bar 00 symmetric tilt grain boundary. A twin-like {33 (3) over bar4} tilt boundary, which is formed via the evolution of {11 (2) over bar1} twin boundary, is commonly found for the first time in the deformed Mg-Y alloy. Via combining high-angle annular dark-field scanning transmission electron microscopy and density functional theory calculations, the formation of {33 (3) over bar4} tilt boundary and the associated segregation of Y atoms are rationalized. Such a finding provides a new vision on twinning behavior for the design of new high-performance Mg alloys. (C) 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.