The atomic structure of {10 \(\bar{{\bf{1}}}\) 2} twin boundary (TB) from a deformed Mg-3Al-1Zn (AZ31) magnesium alloy was examined by using high-resolution transmission electron microscopy (HRTEM). By comparing the lattice structure of TB with the previously established model, a kind of special atomic combinations, here named primitive cells (PCs), were discovered at the TB. The PCs reorientation induced mechanism of twinning in hexagonal-close-packed (HCP) crystals was hence verificated. Meanwhile, the relationship between the misorientation of adjacent layers of PCs and the width of TB was discussed. The verification of the mechanism clarifies the twinning mechanism in HCP crystals and opens up opportunities for further researches.

利用高分辨率透射电子研究了变形Mg-3Al-1Zn（AZ31）镁合金产生的{10 \（\ bar {{\ bf {1}}}） } 2}双晶界（TB）的原子结构显微镜（HRTEM）。通过将TB的晶格结构与先前建立的模型进行比较，在TB处发现了一种特殊的原子组合，这里称为原始细胞（PC）。因此，验证了PCs定向诱导的六方密堆积（HCP）晶体中孪晶的机制。同时，讨论了PC相邻层的取向错误与TB宽度之间的关系。对该机理的验证阐明了HCP晶体中的孪生机理，并为进一步的研究提供了机会。