Effect of unipolar pulsed electric current treatment of the melt of Al – 8 wt-% Si – 0.7 wt-% Fe alloy on iron-containing phases formation and mechanical properties of castings

Abstract

The effect of processing an Al – 8 wt-% Si – 0.7 wt-% Fe melt by a unipolar pulsed electric current on the mechanical properties of castings obtained from it has been investigated. It has been established that the complex of properties has a maximum at j = 7 A cm⁻², ν = 700 Hz. The study of the microstructure of castings obtained from the melt processed in this way, compared with the structure of castings from an untreated melt, showed that treatment with current leads to a partial replacement of large β-phase into the α-phase, and reduction in the size of the remaining β-phase. It is assumed that this effect is associated with a change in the structure of the melt, increasing supercooling.