Effects of electric current pulse on stability of solid/liquid interface of Al–4.5 wt.% Cu alloy during directional solidification

This paper investigates the effects of the electric current pulse (ECP) on the interface stability of Al–4.5% Cu alloy during the directional solidification. Experimental results show both the cellular spacing and the mushy zone depth decrease with increasing current density, moreover, the solid–liquid interface morphology transforms from dendritic to cellular or even planar interface. The secondary dendrites are suppressed due to the homogeneous distribution of the solute and the increase of temperature gradient originated from ECP. The decrease of the cellular spacing results from branching of the cellular tip caused by Joule heat of the current exerting on cellular tip.