In this work, a novel texture modification, termed the ellipse texture, is introduced by the pre-rolling and subsequent annealing (PRA) process in as-extruded (AE) Mg-Gd-Zn (GZ21) alloy. The static recrystallization (SRX) mechanisms and the evolution of microstructure during the PRA process are investigated by electron backscattered diffraction (EBSD), transmission electron microscopy (TEM) and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) techniques. The results show that the introduction of the ellipse texture distribution leads to the improved planar isotropy of the mechanical properties compared with the AE sheets, when tensile along different directions. Accordingly, the Erichsen value (IE value) increases to 5.7 ± 0.1 mm. Furthermore, the activation of non-basal dislocations (prismatic <a> and pyramidal <c+a> dislocations) during the pre-rolled process induces preferred nucleation sites for the SRX grains with the c-axis oriented to TD. The co-segregation of Gd and Zn atoms at grain boundaries leads to the preferred growth of these TD texture component grains. Both the preferred nucleation and growth of the SRX grains contribute to the formation of ellipse texture distribution in the PRA GZ21 alloys.

在这项工作中，通过预轧和后续退火 (PRA) 工艺在挤压态 (AE) Mg-Gd-Zn (GZ21) 合金中引入了一种称为椭圆织构的新型织构修改。通过电子背散射衍射 (EBSD)、透射电子显微镜 (TEM) 和高角度环形暗场扫描透射电子显微镜 (HAADF-STEM) 技术研究了 PRA 过程中的静态再结晶 (SRX) 机制和微观结构的演变. 结果表明，当沿不同方向拉伸时，与AE片材相比，椭圆织构分布的引入导致力学性能的平面各向同性得到改善。因此，埃里克森值（IE 值）增加到 5.7 ± 0.1 mm。此外，非基底位错的激活（棱柱形<a>c轴指向 TD。Gd 和 Zn 原子在晶界处的共偏析导致这些 TD 织构成分晶粒的优选生长。SRX晶粒的优选形核和生长都有助于PRA GZ21合金中椭圆织构分布的形成。