The multi-phase-field (MPF) model coupled with reliable CALPHAD thermodynamic/atomic mobility descriptions, appropriate faceted anisotropy and key experimental validation is employed to perform the quantitative simulation of the microstructure evolution of the hypereutectic Al-16 ​wt%Si alloy during solidification. By considering the effect of latent heat released during the eutectic phase transformation in the simulation, the appropriate entire solidification sequence is obtained. All the characteristics in the as-cast microstructure can be nicely reproduced, including the primary (Si) encircled by the second primary (Al) halo, and the coupled eutectic grains appearing at the Liquid/(Al) interface rather than Liquid/(Si) interface. Moreover, three types of growth patterns of eutectic (Si) with different lengths are distinguished according to the distance between primary (Si) and the nucleation position of eutectic (Si). Furthermore, the evaluated ratios of width to length for 50 eutectic (Si) grains due to the MPF simulation are in good agreement with the experimental data. The quantitative phase-field simulation of the entire solidification process of the hypereutectic Al-16 ​wt%Si alloy in the present work is anticipated to pave the way for revealing the grain refinement mechanism in hypereutectic Al–Si alloys in the future studies.

采用多相场 (MPF) 模型，结合可靠的 CALPHAD 热力学/原子迁移率描述、适当的小面各向异性和关键实验验证，对过共晶 Al-16 wt%Si 合金的微观结构演变进行定量模拟。凝固。通过在模拟中考虑共晶相变过程中释放的潜热的影响，得到合适的整个凝固顺序。铸态显微组织中的所有特征都可以很好地再现，包括被第二次初生 (Al) 晕圈包围的初生 (Si)，以及出现在液体/(Al) 界面而不是液体/(Si) 界面处的耦合共晶晶粒） 界面。而且，根据初生（Si）的距离和共晶（Si）的形核位置，可区分出三种不同长度的共晶（Si）的生长模式。此外，由于 MPF 模拟而评估的 50 个共晶 (Si) 晶粒的宽度与长度的比率与实验数据非常吻合。目前工作中过共晶Al-16wt%Si合金整个凝固过程的定量相场模拟有望为未来研究揭示过共晶Al-Si合金的晶粒细化机制铺平道路。