Using synchrotron X-ray diffraction, tomography and machine-learning enabled phase segmentation strategy, we have studied under operando conditions the nucleation, co-growth and dynamic interplays among the dendritic and multiple intermetallic phases of a typical recycled Al alloy (Al5Cu1.5Fe1Si, wt.%) in solidification with and without ultrasound. The research has revealed and elucidated the underlying mechanisms that drive the formation of the very complex and convoluted Fe-rich phases with rhombic dodecahedron and 3D skeleton networks (the so-called Chinese-script type morphology). Through statistical microstructural analyses and numerical modelling of the ultrasound melt processing, the research has demonstrated that a short period of ultrasound processing of just 7 s in the liquid state is able to reduce the average size of the α-Al dendrites and the Fe-containing intermetallic phases by ∼5 times compared to the cases without ultrasound. For the first time, this work has revealed fully the nucleation and growth dynamics of the convoluted morphology of the Fe-containing intermetallic phases in 4D domain. The research has also demonstrated clearly the beneficial effects of applying ultrasound to control the Fe phases' morphology in recycled Al alloys and it is one of the most effective and green processing strategies.

中文翻译：

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通过同步加速器 X 射线和机器学习对铝合金再生合金中多种富铁金属间化合物在凝固过程中的动态演化进行操作研究


利用同步加速器 X 射线衍射、断层扫描和机器学习支持的相分割策略，我们研究了典型回收铝合金 (Al5Cu1.5Fe1Si、 wt.%)在有和没有超声波的情况下凝固。该研究揭示并阐明了驱动具有菱形十二面体和3D骨架网络（所谓的汉字型形态）的非常复杂且复杂的富铁相形成的潜在机制。通过统计微观结构分析和超声波熔融加工的数值模拟，研究表明，在液态下进行短短 7 秒的超声波加工就能够减小 α-Al 枝晶和含 Fe 的平均尺寸。与没有超声的情况相比，金属间相增加约 5 倍。这项工作首次全面揭示了 4D 域中含 Fe 金属间相的卷积形貌的成核和生长动力学。该研究还清楚地证明了应用超声波控制再生铝合金中铁相形态的有益效果，是最有效、最绿色的加工策略之一。