Twinning-induced dynamic recrystallization in a magnesium alloy extruded at 450 °C

A novel and interesting dynamic recrystallization (DRX) mechanism was observed in a Mg-Al-Zn-Mn magnesium alloy (AZ61) extruded at 450 degrees C. The misorientation distribution of the dynamically recrystallized grains was measured by electron backscatter diffraction (EBSD). The results show that a portion of the grains from DRX satisfy the {10 (1) over bar2} < 10 (1) over bar(1) over bar > twin orientation relationship and indicate that twinning plays an important role in DRX. The EBSD image-quality maps show that the morphologies of the twin boundaries are rough and incoherent. (C) 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.