电磁铸造对Al–Si12.6%共晶合金微观组织的影响

目的 了解外加耦合场作用下Al–Si合金的微观组织演变情况。方法 利用外磁场加强凝固过程中熔体的流动，从而获得合金中各相的形态、分布和取向等，利用扫描电子显微分析技术(SEM)和电子背散射衍射分析技术(EBSD)研究电磁场对Al–Si12.6%共晶合金微观组织的影响规律。结果 在磁场作用下，铸件的组织均匀性增加，初生铝和共晶硅的尺寸均减小，并且随着磁场强度的增大，共晶硅的含量和尺寸呈减小趋势，其形态趋于等轴状，共晶硅附近各铝枝晶之间的外延生长关系消失，相互独立形核和长大。结论 研究成果可以为电磁铸造对Al–Si系共晶合金微观组织研究提供一定的参考。

Effect of Electromagnetic Casting on Microstructure of Al-Si12.6% Eutectic Alloy

The work aims to further understand the microstructure evolution of Al-Si alloy under the coupled field. An external magnetic field was used to strengthen the melt flow during solidification to obtain the morphology, distribution and orientation of various phases in the alloy. Therefore, the effect of electromagnetic field on the microstructure of Al-Si12.6% eutectic alloy was studied by means of scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD). The results showed that under the action of magnetic field, the microstructure uniformity of the casting increased and the size of primary aluminum and eutectic silicon decreased. With the increase of magnetic field strength, the content and size of eutectic silicon decreased and the shape of eutectic silicon tended to be equiaxed. The epitaxial growth relationship between the Al dendrites near the eutectic silicon disappeared and they nucleated and grew independently. The research results can provide reference for studying the effect of electromagnetic casting on the microstructure of Al-Si eutectic alloy.