Effect Mechanism of a Direct Current on the Solidification of Immiscible Alloys

Continuous solidification experiments are carried out with Al-Pb alloys under the effect of a direct current. The microstructure evolution in the samples is calculated. The numerical results obtained indicate that a direct current has great effects on the solidification of immiscible alloys. It mainly affects the microstructure evolution during a liquid-liquid decomposition by changing the spatial motions of the minority phase droplets and the temperature field in front of the solidification interface. A sample with either a well dispersed or a core/shell microstructure can be obtained by solidifying Al-Pb alloys under the effect of properly selected direct currents.