Abstract It is crucial to study grain refinement and refinement mechanism for promoting mechanical properties of Mg alloys. In this work, the influence mechanism of Ca on the grain refinement of Al2MgC2 and Al4C3 in Mg alloys was studied. It shows that Ca is easier to adsorb on the surfaces of Al2MgC2 and Al4C3 particles than Mg, which further promotes the adsorption Mg on the surfaces of Al2MgC2 and Al4C3 particles, leading to more crystal nuclei beyond the critical nucleation radius rK. The interface of Ca replaced Mg-2 is found to be more stable, for both Mg/Al2MgC2 interface and Mg/Al4C3 interface. We further revealed that Ca could effectively migrate from the first-layer to the second-layer in both the adsorption slabs and doped interface slabs under ambient condition.

中文翻译：

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活性钙元素对渗碳镁铝合金晶粒细化的理论研究

摘要 研究晶粒细化和细化机理对提高镁合金的力学性能至关重要。本文研究了Ca对镁合金中Al2MgC2和Al4C3晶粒细化的影响机制。这表明 Ca 比 Mg 更容易吸附在 Al2MgC2 和 Al4C3 颗粒表面，这进一步促进了 Mg 在 Al2MgC2 和 Al4C3 颗粒表面的吸附，导致超过临界成核半径 rK 的更多晶核。发现 Ca 取代 Mg-2 的界面更稳定，对于 Mg/Al2MgC2 界面和 Mg/Al4C3 界面。我们进一步发现，在环境条件下，Ca 可以有效地从吸附板和掺杂界面板中的第一层迁移到第二层。