The evolution of the 3D Fe-rich phases of Al–7.0Si–1.2Fe alloys with different Mn contents was visualized and characterized using synchrotron X-ray computed tomography, and the effect of Fe-rich phases with typical morphologies on the fracture behavior during tensile testing was analyzed. The results showed that the Fe-rich phase changed from platelet-like β-Al₅FeSi into α-Al₁₅(FeMn)₃Si₂ with various morphologies after the addition of Mn. The Mn addition not only significantly reduced the volume fraction, equivalent diameter and interconnectivity of the Fe-rich phase but also greatly increased the sphericity, surface thickness, and distribution of the mean curvature and surface thickness. Furthermore, the equivalent diameter of α-Al₁₅(FeMn)₃Si₂ had an inverse exponential function relationship with its sphericity. The 3D morphology of α-Al₁₅(FeMn)₃Si₂ can be summarized as massive and regular polyhedrons, hollow and regular polyhedrons, and multibranched polyhedrons. The fraction of the different 3D morphologies in each alloy is related to the Mn content, where excess Mn increased the number and volume fraction of the large Fe-rich particles with a low sphericity. The ductility of each alloy was significantly improved by the addition of Mn but gradually decreased when the Mn/Fe ratio exceeded 1.2. The increase in large α-Al₁₅(MnFe)₃Si₂ with a low sphericity was the main reason for the decreased ductility of alloys with a high Mn content.

使用同步加速器 X 射线计算机断层扫描对具有不同 Mn 含量的 Al-7.0Si-1.2Fe 合金的 3D 富铁相的演变进行了可视化和表征，以及具有典型形态的富铁相对断裂行为的影响拉伸试验进行了分析。结果表明，加入Mn后，富铁相由片状β-Al ₅ FeSi转变为各种形貌的α-Al ₁₅ (FeMn) ₃ Si ₂。Mn的加入不仅显着降低了富铁相的体积分数、当量直径和互连性，而且大大增加了球度、表面厚度以及平均曲率和表面厚度的分布。此外，α-Al 的等效直径₁₅ (FeMn) ₃ Si ₂与其球形度具有反指数函数关系。α-Al ₁₅ (FeMn) ₃ Si ₂的3D形貌可概括为块状规则多面体、空心规则多面体和多支链多面体。每种合金中不同 3D 形貌的分数与 Mn 含量有关，其中过量的 Mn 增加了具有低球形度的大富铁颗粒的数量和体积分数。加入Mn后，各合金的延展性显着提高，但当Mn/Fe比超过1.2时，延展性逐渐下降。增加大α-Al ₁₅ (MnFe) ₃ Si ₂ 低球形度是高Mn含量合金延展性降低的主要原因。