In the current study, high strain-rate rolling (≥10 s⁻¹) has been successfully employed to produce Mg-3Al-1Zn alloy sheets to a high reduction of 82% with a fine grain structure in a single pass. The underlying mechanism of forming primary and secondary edge cracks has been investigated. It is found that dynamic recrystallization (DRX) induced by subgrains tends to blunt cracks, while twinning-induced DRX is mainly observed around sharp crack tips. The motion of emitted dislocations from blunted cracks is inhibited by the DRX grain boundaries. This, on one hand, increases local work hardening, and on the other hand, causes stress concentration along grain boundaries especially in the triple junctions leading to the formation of secondary cracks.

在当前的研究中，高应变速率轧制（≥10s ^-1）已成功地用于生产Mg-3Al-1Zn合金薄板，该合金薄板一次成型可减少82％的高晶粒组织。已经研究了形成初级和次级边缘裂纹的潜在机理。发现由亚晶粒引起的动态再结晶（DRX）倾向于使裂纹变钝，而孪晶诱导的DRX主要在尖锐的裂纹尖端附近观察到。DRX晶界抑制了钝化裂纹发出的位错运动。一方面，这会增加局部加工硬化，另一方面，会导致应力沿晶界集中，特别是在三重结中，从而导致形成二次裂纹。