Influence of direct electric current on solidification process of Al–Si alloy

Abstract

The effect of direct electric current on redistribution and microstructure of primary silicon in Al–Si melt during the solidification refining process was studied. Electric current generates a Joule heat, which slows down the cooling rate of the furnace. The precipitated area of primary silicon decreases from 100% to 36.67% with the increase of current density from 0 A/m2 to 1.5×106 A/m2. Furthermore, direct current causes a convection leading to the migration of primary silicon in the opposite direction of electric field, which forms the accumulation area. The morphologies of primary silicon and the redistribution of B impurity were investigated under the effect of electric current.