Generalized stacking fault (GSF) energies of the basal $\left\{0001\right\}〈11\bar{2}0〉$，prismatic $\left\{10\bar{1}0\right\}〈11\bar{2}0〉$ and pyramidal $\left\{11\bar{2}2\right\}〈11\bar{2}3〉$ slip systems in the primary phase of Mg-Sn based-alloys have been studied using first-principles calculations in this work, where twenty-one third elements (X) have been taken in to consideration for their solution in primary (Mg, Sn) phase. The relative positions of Sn and X in Mg₁₄₂Sn₁X₁ supercell have been determined by searching the minimum formation energies points. It is shown that, with alloying-elements of Sn and X, the unstable stacking fault energy (${\gamma }_{\mathit{us}}$) of the basal and prismatic slip systems are decreased compared with that of Mg₁₄₄. For the pyramidal slip system, only certain second-alloying-elements, namely Ag, Al, Cd, Ga, In, Li and Zn, soluted into the Mg-Sn alloys, make the ${\gamma }_{\mathit{us}}$ lower than that of pure Mg. The atomic radius of element X has a significant impact on the ${\gamma }_{\mathit{us}}$ value of Mg₁₄₂Sn₁X₁, and also indirectly affects the ${\gamma }_{\mathit{us}}$ by affecting the relative substitution positions of Sn and X atoms in the structure. Accordingly, the plastic formability parameters $\chi$ have been analyzed based on the calculated stacking fault energy (SFE) values. The effects of second-alloying-elements on GSF energies and $\chi$ provide a guidance for the design of high-performance multi-elements-alloying Mg alloys.

基础的广义堆垛层错 (GSF) 能量 $\left\{0001\right\}〈11\bar{2}0〉$，棱柱形 $\left\{10\bar{1}0\right\}〈11\bar{2}0〉$ 和金字塔 $\left\{11\bar{2}2\right\}〈11\bar{2}3〉$在这项工作中，使用第一性原理计算研究了 Mg-Sn 基合金初相中的滑移系统，其中考虑了 21 分之三元素 (X) 在初相 (Mg, Sn) 中的溶液阶段。通过寻找最小形成能点确定了Mg ₁₄₂ Sn ₁ X ₁超胞中Sn和X的相对位置。结果表明，Sn和X合金元素的不稳定堆垛层错能（${\gamma }_{\mathit{我们}}$) 的基底和棱柱滑移系统与 Mg ₁₄₄相比有所降低。对于锥体滑移系统，只有某些第二合金元素，即 Ag、Al、Cd、Ga、In、Li 和 Zn 固溶到 Mg-Sn 合金中，才能使${\gamma }_{\mathit{我们}}$低于纯镁。元素 X 的原子半径对${\gamma }_{\mathit{我们}}$Mg ₁₄₂ Sn ₁ X _{1 的值}，也间接影响${\gamma }_{\mathit{我们}}$通过影响结构中 Sn 和 X 原子的相对取代位置。因此，塑性成形参数$\chi$已根据计算的堆垛层错能 (SFE) 值进行分析。二次合金元素对 GSF 能量的影响$\chi$ 为高性能多元素合金镁合金的设计提供指导。