稀土对锡铅共晶合金定向凝固组织的影响

同稀土含量地锡铅共晶合金定向凝固组织的影响，发现稀土的加入使片间距减小，片支断续、不规稀土量增加使结晶组织向胞晶转变，且凝固过程中由于稀土的“亲Ｓｎ”作用，使锡铅共晶点偏移，促进初生富铅相生成，出现亚共晶生长层；稀土化合物对锡铅的凝固过程几乎没有影响。

Influence of Rare Earths on Microstructure of Directional Solidified Tin Lead Eutectic Alloy

The influence of RE on the microstructure of directional solidified Sn Pb alloy has been studied. The addition of RE caused chopping and irregular lamellar, and smaller lamellar spacing. When RE content increased, the microstructure became peritectic structure. Moreover, the eutectic point of Sn Pb alloy deviated because of the affinity between RE and Sn. Meanwhile it resulted in the existence of primary Pb rich phase containing hypoeutectic layers. Sn RE intermetallic compound has little effect on the solidification of Sn Pb alloy.