热轧制后的Mg-Al-Zn-Mn-Ca镁合金具有椭圆形织构特征。为解决该合金成形过程中展现出的对称性不足等问题，本工作通过热轧制-剪切-弯曲(HRSB)工艺，优化了Mg-2Al-2Zn-0.4Mn-0.5Ca镁合金板材的织构，进而改善了材料的室温各向异性。利用EBSD和XRD等表征技术，系统研究了Mg-2Al-2Zn-0.4Mn-0.5Ca镁合金板材在退火过程中的微观结构演化和非基面织构形成机理。结果表明，热轧制后退火温度高于350 ℃时，板材开始表现出沿横向(TD)扩展的椭圆形织构。剪切-弯曲及400 ℃退火处理后，变形过程产生的{\mathrm{10}\overline{\mathrm{1}}\mathrm{2}}拉伸孪晶界未发生明显静态再结晶，导致20°~70°范围内对称织构的组分增大，甚至形成一种环形织构。当退火温度升高到450 ℃时，Mg-2Al-2Zn-0.4Mn-0.5Ca合金中基本无法观察到{\mathrm{10}\overline{\mathrm{1}}\mathrm{2}}拉伸孪晶，析出相数量增多，再结晶过程中取向随机的晶粒形核，导致环形织构特征消失。HRSB变形过程中，锥面<c + a>滑移被大量激活，成为几何必需位错的主要组成部分。Al、Ca等元素在晶界处共偏析引发的新低能晶界以及非基面滑移导致的取向梯度共同促进了非基面织构的形成。

The Mg-Al-Zn-Mn-Ca magnesium alloy, after hot rolling, forms an elliptical texture, providing good application prospects. However, challenges such as poor symmetry, similar to basal textures, persist in elliptical texture formation. This study explores optimizing the texture of Mg-2Al-02Zn-0.4Mn-0.5Ca Mg alloy sheets using a hot rolling-shearing-bending (HRSB) treatment to improve their room temperature mechanical properties. The research systematically investigates structural evolution during the annealing process and the mechanism behind nonbasal texture formation, using EBSD, XRD, and other characterization techniques. The results show that after annealing at temperatures above 350 ^oC following hot rolling, the sheets develop an elliptical texture extending toward the transverse direction (TD). Following HRSB treatment and annealing at 400 ^oC annealing, the {\mathrm{10}\overline{\mathrm{1}}\mathrm{2}} extension twins generated during deformation remain uncrystallized, leading to an increase in the relatively symmetrical texture components between 20° and 70°. This also results in the formation of a ring texture. However, as the annealing temperature increases to 450 ^oC, the {\mathrm{10}\overline{\mathrm{1}}\mathrm{2}} extension twins nearly disappear, precipitation phases increase, and the nucleation of randomly oriented grains during recrystallization causes the circular texture characteristics to disappear. During the HRSB deformation process, the pyramidal <c + a> slip becomes significantly activated, dominating the primary dislocation density. The low-energy grain boundaries caused by the co-segregation of Al and Ca atoms at the grain boundaries, as well as the orientation gradient induced by the non-basal slip, jointly contribute to the formation of the non-basal texture.