The effects of Mn addition on the microstructure and mechanical properties of Mg–Zn–Sn alloys have been investigated by optical microscopy (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and uniaxial tensile tests. The results show that the addition of Mn can significantly improve the mechanical properties of the as-extruded and aged Mg–Zn–Sn alloys, which is mainly due to the grain refinement and precipitation strengthening. For the as-extruded alloys, the Mn element mainly exists in the form of α-Mn particle phase, which is dispersed in the matrix and play the role of fine grain strengthening and dispersion strengthening. For the single-aged and double-aged alloys, the dispersed α-Mn particle phases can also serve as the heterogeneous nucleation cores of rod-like ${\beta }_1^{\text{'}}$ precipitates during the ageing treatment, which is beneficial to the nucleation rate of the precipitates. The crystallographic characteristics research shows that the directional relationship between α-Mg, ${\beta }_1^{\text{'}}$ and α-Mn is ${\left[2\overline{1}\overline{1}0\right]}_{\alpha }∕∕{\left[0001\right]}_{{\beta }_1^{’}}∕∕{\left[012\right]}_{\text{Mn}}$, i.e., the ${\beta }_1^{\text{'}}$ phase can form a coherent interface on the α-Mn phase.

通过光学显微镜（OM），X射线衍射（XRD），扫描电子显微镜（SEM），透射电子显微镜（TEM）和光学显微镜（OM）研究了Mn添加对Mg-Zn-Sn合金的组织和力学性能的影响。单轴拉伸试验。结果表明，添加Mn可以显着改善经挤压和时效处理的Mg-Zn-Sn合金的机械性能，这主要归因于晶粒细化和析出强化。对于刚挤压的合金，Mn元素主要以α-Mn颗粒相的形式存在，它分散在基体中并起细晶粒强化和弥散强化的作用。对于单时效和双时效合金，分散的α-Mn颗粒相还可以作为棒状的不均匀形核核${\beta }_{\mathrm{1个}}^{\text{'}}$时效处理过程中会产生沉淀，这有利于沉淀的成核速率。晶体学特性研究表明，α-Mg，${\beta }_{\mathrm{1个}}^{\text{'}}$ α-Mn为 ${\left[2\overline{\mathrm{1个}}\overline{\mathrm{1个}}0\right]}_{\alpha }∕∕{\left[0001\right]}_{{\beta }_{\mathrm{1个}}^{\text{'}}}∕∕{\left[012\right]}_{\text{锰}}$，即 ${\beta }_{\mathrm{1个}}^{\text{'}}$ 相可以在α-Mn相上形成相干界面。