The effect of rare earth element segregation on grain boundary energy and mobility in magnesium and ensuing texture weakening

This paper elucidates a key puzzle related to texture randomization - effect of rare earth on grain boundaries. We use electron back-scatter diffraction and molecular dynamics to compare recrystallization between pure Mg and a Y-containing alloy. The alloy's texture components were initially similar, but the large (a) fiber grains in pure Mg overtook all other components. Y segregation homogenized the energies of (a) fiber grain boundaries, curtailing conventional recrystallization. Grain boundary mobilities were reduced proportionally to the energy stabilization, reducing the dominance of < 1010 > extrusion texture. This allows other grain orientations to stabilize thus producing a more randomize texture. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.