研究了铸件形状因素对雀斑形成的影响,揭示了雀斑产生的几个新特点, 如型芯会诱导铸件内表面雀斑产生，雀斑易于产生的部位是铸件的边角而不是平面上, 是外廓收缩而不是扩张处等。提出了糊状区液体流动的趋壁效应这一新理念来合理解释这些超出了现有知识的新发现。本文的研究结果提升了雀斑研究领域的理论水平，对实际生产中雀斑的预防和控制具有重大的理论和实用意义。

The casting shape effect on the freckle formation in directionally solidified superalloys was investigated, revealing some new characters about the freckle occurrence. It was observed that the ceramic core can lead to the freckling inside the castings. The freckles are preferably formed on the edge instead of the smooth surfaces of the castings. The freckle formation is promoted on the contracting sections but suppressed by expanding ones. These phenomena are contrast to the today’s freckling knowledge and could be explained by using the proposed coanda effect of liquid flow in the mushy zone, leading to a better understanding of freckle formation.