Grain growth and texture evolution during annealing in an indirect-extruded Mg-1Gd alloy

RE (rare earth)-texture component has been reported to be responsible for improved formability and ductility in RE-containing Mg alloys. Grain growth and texture evolution during annealing of Mg-1Gd alloy was investigated after indirect extrusion and quenching to reveal the formation mechanisms of the RE texture component. In the as-extruded Mg-1Gd sample, both the recrystallized grains and large elongated grainsare oriented mainly with 〈101¯0〉 orientation parallel to the extrusion direction (ED). The preferred growth of the 〈21¯1¯1〉 grain with its 〈21¯1¯1〉 orientation parallel to ED has been observed during recrystallization annealing, leading to the gradual strengthening of 〈21¯1¯1〉 RE-texture component at the expense of the 〈101¯0〉 component with increasing annealing temperature. The driving force for the preferred grain growth is the difference in stored energy between the 〈21¯1¯1〉 grains and the 〈101¯0〉 grains. Abnormal growth of the 〈101¯0〉 grain takes place during long-time annealing, resulting in the strengthening of 〈101¯0〉 component texture, which can be explained by a texture effect.