Liquid-liquid phase separation and solidification behavior of Al-Bi-Sn monotectic alloy

In this study, the liquid-liquid phase separation of four kinds of Al-Bi-Sn immiscible melts and the formation mechanism of core-shell structure were studied using electrical resistivity and thermodynamics method. The thermodynamic characteristics and micromorphology were analyzed by DSC, XRD, SEM and EDS. The resistivity results showed that the non-linear change of ρ-T curve above the monotectic reaction temperature reveals the occurrence of liquid-liquid phase separation. Solidification microstructure and the core-shell structure of Al-Bi-Sn immiscible alloy can be controlled by adjusting the composition of alloy. The core/shell structure of Al-rich phase/Sn-Bi-rich phase can be obtained in the Al60Bi24Sn16 alloy cast in the copper mold.