Abstract Long-period stacking ordered (LPSO) structures, like 9R, 12R, 15R and 18R phases etc., play a key role in improving the mechanical properties of Al alloys. In the present study the Gaussian-Like distribution (GLD) model was utilized to investigate the effects of solute atoms (Cu, Fe, Ga, Ge, Li, Mg, Sc, Si, Sn, Sr, Ti, Y, Zn) on these phase stabilizations in Al alloys by first-principles calculations. The interaction energies between solute atoms and these phases were strictly calculated. The results suggested that the solute segregations showed different characteristics in these phase structures, and solute atoms (Ga, Ge, Si, Sn, Sr, Y) tended to segregate to the stacking fault (SF) planes of them, and Sr atom was the easiest to promote the stabilization of 15R phase compared to other structures. High solute concentrations promoted the stabilizations of these phases, while high temperature inhibited their stabilizations. In the light of the degrees of reducing the intrinsic stacking fault energies (ISFEs), the solute atoms can be ranked by: (a) For 9R and 12R phases, Sr > Y > Sn > Sc; (b) For 15R and 18R phases, Sr > Y > Sc > Sn. Thus, it may be concluded that Sr and Y atoms are hopeful to become the underlying candidates for exploring and exploiting high-performance Al alloys with LPSO structures.

中文翻译：

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高性能铝合金长周期堆积有序结构稳定机制的第一性原理探索

摘要 9R、12R、15R和18R相等长周期堆积有序(LPSO)结构对提高铝合金的力学性能起着关键作用。在本研究中，类高斯分布 (GLD) 模型用于研究溶质原子（Cu、Fe、Ga、Ge、Li、Mg、Sc、Si、Sn、Sr、Ti、Y、Zn）对通过第一性原理计算，铝合金中的这些相稳定。溶质原子与这些相之间的相互作用能经过严格计算。结果表明，这些相结构中的溶质偏析表现出不同的特征，溶质原子（Ga、Ge、Si、Sn、Sr、Y）倾向于偏析到它们的堆垛层错（SF）面，Sr原子是与其他结构相比，最容易促进 15R 相的稳定。高溶质浓度促进了这些相的稳定，而高温抑制了它们的稳定。根据本征堆垛层错能 (ISFE) 的降低程度，溶质原子可以排序为： (a) 对于 9R 和 12R 相，Sr > Y > Sn > Sc；(b) 对于 15R 和 18R 相，Sr > Y > Sc > Sn。因此，可以得出结论，Sr 和 Y 原子有望成为探索和开发具有 LPSO 结构的高性能铝合金的潜在候选者。