The deformation mechanism and precipitation behavior of Al-5.8Cu-0.35 Mg-(0.3Sn) (wt.%) alloys were intensively investigated by microstructure characterizations and mechanical tests in this work. The experimental results showed that the added Sn elements can induce profound impacts on the alloys in three manners: (1) the formation of Mg₂Sn particles with excellent thermal stability can create particle-stimulated nucleation effect to facilitate dynamic recrystallization during hot deformation. Furthermore, the fine Mg₂Sn particles distributed at subgrain boundaries obviously inhibited the recrystallized grain growth during the solution treatment; (2) the suppression of natural aging was because there was insufficient releasing of vacancies from Sn-vacancy clusters at room temperature; (3) the accelerated artificial aging with lowered hardening effect was owing to both Sn-vacancy clusters inhibited the annihilation of quenching vacancies and reduced concentration of solute Mg consumed by the stable Mg₂Sn particles. Finally, the underlying mechanisms were elucidated in combination microstructure features with mechanical responses in the alloys.

通过显微组织表征和力学测试，深入研究了Al-5.8Cu-0.35 Mg-（0.3Sn）（wt。％）合金的变形机理和析出行为。实验结果表明，添加的Sn元素可以通过三种方式对合金产生深远的影响：（1）具有良好热稳定性的Mg ₂ Sn颗粒的形成可以产生颗粒刺激的成核作用，从而促进热变形过程中的动态再结晶。此外，细镁₂在固溶处理过程中，分布在亚晶界的Sn颗粒明显抑制了再结晶晶粒的生长。（2）抑制自然老化的原因是室温下锡空位簇中空位的释放不足；（3）由于锡空位团簇均抑制了淬火空位的and灭和稳定Mg ₂ Sn颗粒消耗的溶质Mg浓度降低，加速了人工时效，降低了硬化效果。最后，结合合金的微观结构特征和机械响应，阐明了潜在的机理。