Effect of interface anisotropy on tilted growth of eutectics: A phase field study

Interfacial energy anisotropy plays an important role in tilted growth of eutectics. However, previous studies mainly focused on the solid-solid interface energy anisotropy, and whether the solid-liquid interface energy anisotropy can significantly affect the tilted growth of eutectics still remains unclear. In this study, a multi-phase field model is employed to investigate both the effect of solid-liquid interfacial energy anisotropy and the effect of solid-solid interfacial energy anisotropy on tilted growth of eutectics. The findings reveal that both the solid-liquid interfacial energy anisotropy and the solid-solid interfacial energy anisotropy can induce the tilted growth of eutectics. The results also demonstrate that when the rotation angle is within a range of 30°-60°, the growth of tilted eutectics is governed jointly by the solid-solid interfacial energy anisotropy and the solid-liquid interfacial energy anisotropy; otherwise, it is mainly controlled by the solid-solid interfacial energy anisotropy. Further analysis shows that the unequal pinning angle at triple point caused by the adjustment of the force balance results in different solute-diffusion rates on both sides of triple point. This will further induce an asymmetrical concentration distribution along the pulling direction near the solid-liquid interface and the tilted growth of eutectics. Our findings not only shed light on the formation mechanism of tilted eutectics but also provide theoretical guidance for controlling the microstructure evolution during eutectic solidification.