本文论述了Al-4.5％Cu合金在定向凝固条件下,铈对其固液界面形态和稳定性的影响。结果表明,铈使铜的分配系数减小,合金的熔化潜热增加,固液界面前沿成分过冷和溶质的不稳定扰动增大,因而导致合金生长稳定性下降,平面-胞晶-枝晶生长方式转变加速,二次枝晶间距减小。 This article discusses the influence of cerium on the morphology and stability of the solid-liquid interface of Al-4.5% Cu alloy under directional solidification conditions. The results show that cerium reduces the copper partition coefficient, increases the latent heat of fusion, and leads to overcooling of the liquid-solid interface and instable disturbance of solute. As a result, the growth stability of the alloy decreases and the plane-cell-crystal-dendrite growth Mode change accelerated, secondary dendrite spacing decreases.