One of the main challenges in processing aluminum alloys in the liquid state is the avoidance of the formation of double oxide films and their incorporation into the final parts. Bifilms in liquid alloys can act as heterogeneous nucleation sites for primary intermetallic compounds (IMCs), which phenomenon can be utilized for their aided sedimentation. In this study, TiAlSi IMCs were used for the sedimentation treatment of a liquid Al–Si–Mg–Cu alloy. The interactions between IMCs and bifilms were studied by computed tomography (CT) and scanning electron microscopy (SEM), while the changes in melt quality were assessed by the CT analysis of reduced pressure test (RPT) samples. Additionally, the grain refinement effect of Ti-addition was studied by grain size measurements. It was found that (Al, Si)₃Ti particles became attached to bifilms, and their simultaneous sedimentation resulted in lowered porosity. However, the attachment of IMCs to the surface oxide layer caused Ti-macrosegregation in the top region of the melt. The attachment of (Al, Si)₃Ti intermetallic particles is caused by the heterogeneous nucleation of IMCs on oxide films and the partial engulfment of oxide film segments during the growth of the (Al, Si)₃Ti particles. Investigations of the pore surfaces support the theory of bifilm-initiated pore formation.

加工液态铝合金的主要挑战之一是避免形成双氧化膜并将其掺入最终零件中。液态合金中的双膜可以作为初级金属间化合物 (IMC) 的异质成核位点，这种现象可用于辅助沉降。在本研究中，TiAlSi IMCs 用于液体 Al-Si-Mg-Cu 合金的沉降处理。通过计算机断层扫描 (CT) 和扫描电子显微镜 (SEM) 研究 IMC 和双膜之间的相互作用，而通过减压测试 (RPT) 样品的 CT 分析评估熔体质量的变化。此外，通过晶粒尺寸测量研究了 Ti 添加的晶粒细化效果。发现 (Al, Si) ₃Ti 颗粒附着在双膜上，它们同时沉降导致孔隙率降低。然而，IMC 与表面氧化层的附着导致了熔体顶部区域的 Ti 宏观偏析。_{(Al,Si) 3Ti}金属间化合物颗粒的附着是由IMCs在氧化膜上的异质形核和(Al,Si)3Ti颗粒生长过程中氧化膜片段的部分包埋引起_的。对孔表面的研究支持双膜引发孔形成的理论。