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采用硅油净化法使大体积Pb－50％Bi亚共品合金和Pb－29．2％Bi包晶合金分别获得了45K（0．11TL）和117K（0．23TL）的过冷度，并对这两种合金快速凝固过程中ε金属间化合物相的组织形态及随过冷度的变化规律进行了探讨，对于Pb－50％Bi亚共晶合金，实验发现ε相以枝晶方式生长，随着过冷度的增大，ε相枝晶细化显著，最大过冷度处一次和二次枝晶间距细化达一个数量级，同时在过冷度达45K的试样中发现了ε相的表面形核，在试作内部ε枝晶相互支叉形成网状，对于Pb－292％Bi包晶合金，当过冷度较小时包晶反应持证明显，但当过冷度达到117K时包品区应被抑制，ε相直接从液相中形成，凝固组织为单相ε金属间化合物为了进一步揭示亚共晶合金中ε相技晶生长动力学特征和包晶合金中的相选择及组织变化规律，根据经典形核理论和快速枝晶生长理论进行了分析计算
The undercooling of 45K (0.11TL) and 117K (0.23TL) were obtained for the large volume Pb-50% Bi sub-base alloy and the Pb-29.2% Bi peritectic alloy by the silicone oil purification method, respectively. The morphology of the intermetallic compound phase ε and the variation with the undercooling of the two alloys during rapid solidification were investigated. For the Pb-50% Bi hypoeutectic alloy, ε phase was found to grow dendritically With the increase of undercooling, the dendritic refinement of ε phase is significant. The first and second dendrite spacing at the maximum undercooling is refined by an order of magnitude. At the same time, ε phase is found in the sample with subcooling of 45K In the case of Pb-292% Bi-perovskite alloy, the peritectic reaction holds well when the degree of subcooling is small, but when the undercooling reaches 117 K In order to further reveal the kinetics of ε-phase crystal growth in hypoeutectic alloys and the phase selection and microstructure in the peritectic alloys, the ε-phase is formed directly from the liquid phase and the solidified microstructure is a single-phase ε intermetallic compound. The variation rule is based on classical nucleation theory and rapid dendrite growth theory Analysis calculated