Twin recrystallization mechanisms and exceptional contribution to texture evolution during annealing in a magnesium alloy

摘要

The formability and mechanical properties of Mg alloys are strongly related to the crystallographic basal\udtexture. Deformation twins form extensively after mechanical processing. Recrystallized grains originating\udfrom twins usually randomize the texture and therefore weaken the strong deformed texture. It is\udcrucial to understand different recrystallization mechanisms as a function of twin type and therefore\udtheir corresponding contribution to texture modification. This work shows that the recrystallization\udvolume fraction formed within twins has been completely underestimated. Specifically, recrystallized\udgrains originating from double twins make the main contribution to texture modification, which contrasts\udto the opposite view that has been reported in the past decades. The preferential nucleation site,\udsubsequent grain growth and evolution of recrystallization texture in double twins has been tracked in\udindividual twins through the whole annealing process for the first time. After annealing for 378 min at\ud490 �C, the volume fraction of total recrystallization was ~75.7%, while the recrystallized volume fraction\udoriginating from double twins and double twin-grain boundary intersections was ~52.9%, which represents\ud~69.9% of the total volume fraction recrystallization. Recrystallization mechanisms related to\udvarious twin types, twin variants, twin-twin and twin-grain boundaries intersections are precisely\uddetermined. These findings could lead new insight to design new wrought alloys and improve formability\udof commercial alloys