Influence of rare earths on the directional solidification microstructure of tin-lead eutectic alloy

The research on the influence of RE on the directional solidified microstructure of tin-lead alloy reveals that the addition of RE can cause chopping and irregular lamellar and smaller lamellar spacing. When RE content increases, the microstructure changes to peritectic structure. Moreover, the eutectic point of Sn-Pb alloy deviates because the affinity of RE for Sn, which results in the existence of primary Pb-rich phases contained hypoeutectic grown layers. Sn-RE intermetallic compound has no effect on the solidification of Sn-Pb alloy.