Magnetic field-assisted solidification of W319 Al alloy qualified by high-speed synchrotron tomography
Magnetic field-assisted solidification of W319 Al alloy qualified by high-speed synchrotron tomography
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DOI：
10.1016/j.jallcom.2022.168691
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发表时间：
2022-12
影响因子：
6.2
通讯作者：
Zihan Song;E. Boller;A. Rack;P. Lee;B. Cai
中科院分区：
文献类型：
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作者：
Zihan Song;E. Boller;A. Rack;P. Lee;B. Cai
磁场已被广泛用于控制凝固过程。本文采用高速同步加速器x射线断层成像技术研究了磁场对凝固的影响。研究了Al-Si-Cu基W319合金在旋转过程中，在无0.5 T横向磁场和磁场作用下垂直向上定向凝固的过程。结果表明，磁场对初生α-Al相和次生β-Al5FeSi金属间化合物（IMCs）均有较强的影响。在无磁场条件下，粗晶α-Al初生枝晶存在较大的宏观偏析区。施加磁场时，枝晶细得多，一次臂间距小，而宏观偏析几乎消除。析出的溶质被挤出细枝晶，堆积在略高于固液界面的地方，导致次生β- imc呈梯度分布。这项工作表明，在横向磁场下旋转样品是一种简单而有效的均匀温度和成分分布的方法，可用于控制凝固过程中初生相和富铁金属间化合物的分布。
Magnetic fields have been widely used to control solidification processes. Here, high-speed synchrotron X-ray tomography was used to study the effect of magnetic fields on solidification. We investigated vertically upward directional solidification of an Al-Si-Cu based W319 alloy without and with a transverse magnetic field of 0.5 T while the sample was rotating. The results revealed the strong effect of a magnetic field on both the primary α-Al phase and secondary β-Al5FeSi intermetallic compounds (IMCs). Without the magnetic field, coarse primary α-Al dendrites were observed with a large macro-segregation zone. When a magnetic field is imposed, much finer dendrites with smaller primary arm spacing were obtained, while macro-segregation was almost eliminated. Segregated solutes were pushed out of the fine dendrites and piled up slightly above the solid/liquid interface, leading to a gradient distribution of the secondary β-IMCs. This work demonstrates that rotating the sample under a transversal magnetic field is a simple yet effective method to homogenise the temperature and composition distributions, which can be used to control the primary phase and the distribution of iron-rich intermetallics during solidification.