Quasi-in-situ EBSD Study of the Microstructure and Texture Evolution During Static Recrystallization in an Extruded Mg-Mn-Ce Alloy

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A quasi-in-situ electron backscatter diffraction (EBSD) technique is used to study the microstructure and texture evolution in an extruded Mg-1Mn-0.2Ce (wt.%) alloy during annealing at 400°C. The as-extruded alloy has a bimodal and partially recrystallized microstructure with a strong [{10}bar{1}{text{0}}]//ED basal texture (ED represents extrusion direction). Upon annealing, the strong [{10}bar{1}{text{0}}]//ED texture is mitigated and gradually replaced by a major rare earth (RE)-texture and minor texture components lying within an arc between text{[10}bar{1}{text{0}}]//ED and text{[11}bar{2}text{0]}//ED. The RE-texture component observed from localized quasi-in-situ EBSD of a randomly selected area is text{[85}bar{13}text{6]}//ED, which is ~8.1° from the [{44}bar{8}{text{3}}]//ED RE-texture observed in the bulk sample. The texture change during quasi-in-situ annealing is associated with the preferential growth of the recrystallized (RX-ed) grains whose orientations are near text{[85}bar{13}text{6]}//ED and text{[32}bar{5}text{0]}//ED, at the expense of both RX-ed and deformed grains with [{10}bar{1}{text{0}}]//ED orientations. This grain growth process mainly occurs in the deformation bands, where there is an agglomeration of the basal <a> and/or pyramidal II <c+a> geometrically necessary dislocations (GNDs). The observed preferential grain growth could be due to the relatively low energy stored in these RX-ed grains that have specific orientations.