Most complex engineering components experience varied loading in use. We conducted successive experiments of cyclic tensile deformation followed by electron-backscattered diffraction imaging of the same area on each of several magnesium alloy (ZM) sample to investigate the microstructure and texture evolution during cyclic loading. In this way we correlated the evolving deformed microstructure of cyclically loaded magnesium to the initial grain orientations. To investigate the effects of the strain path, the behaviour of samples with and without pre-compression was compared. Twins can propagate from grain to grain and twin chains will form in the material without any pre-deformation. Twin chains are a result of twin transmission at grain boundaries and twin transmission frequency decreases with increasing grain boundary angles. In the absence of pre-compression, the extension twin fraction rises from 0.003 to 0.019 after two cycles of tensile loading to a strain of 0.03, after which it changes only slightly as strain is increased. Twin chains in the pre-compressed specimen are activated without any obvious dependence on the matrix orientation. The fraction of extension twinning is 0.2 for the pre-compressed specimen. After a cycle of tensile loading to a total plastic strain of 0.015, 90% of the extension twins undergo detwinning. The detwinning starts just after reverse loading. Secondary twins forming within primary twin interfaces start to nucleate in the microstructure of the pre-compressed material at an early stage (at plastic strain values of 0.056). This is different from the nucleation of secondary twins in the material without pre-compression that occurs at a strain of 0.104. The early formation of secondary twinning is due to the presence of residual primary twins in the microstructure of the pre-compressed material as a result of detwinning of the initial twins.

大多数复杂的工程组件在使用中都会承受不同的负载。我们进行了循环拉伸变形的连续实验，然后对几种镁合金 (ZM) 样品中的每一个进行了相同区域的电子背散射衍射成像，以研究循环加载过程中的微观结构和织构演变。通过这种方式，我们将循环加载的镁的演变变形微观结构与初始晶粒取向相关联。为了研究应变路径的影响，比较了有和没有预压缩的样品的行为。双胞胎可以从谷物传播到谷物，双链将在材料中形成而没有任何预变形。双链是晶界处双传输的结果，双传输频率随着晶界角度的增加而降低。在没有预压缩的情况下，拉伸孪晶分数在两个拉伸加载循环后从 0.003 上升到 0.019，应变为 0.03，此后随着应变的增加，它的变化很小。预压缩试样中的双链被激活，对基体方向没有任何明显的依赖性。预压缩试样的拉伸孪晶分数为 0.2。经过一个循环拉伸加载至 0.015 的总塑性应变后，90% 的拉伸孪晶发生解孪晶。在反向加载后立即开始解缠。在初级孪晶界面内形成的次级孪晶在早期开始在预压缩材料的微观结构中成核（塑性应变值为 0.056）。这与在应变为 0.104 时发生的没有预压缩的材料中二次孪晶的成核不同。二次孪晶的早期形成是由于初始孪晶的去孪晶导致预压缩材料的微观结构中存在残余的初生孪晶。