Reduction of Fe concentration in Al–4Si–1Fe–1Cu–0.5Zn–0.5Mn alloys with S

Abstract

In this article, the effect of sulfur on the reduction of Fe concentration in aluminum alloy scraps was investigated. The iron content decreases from 1.224 wt% to <0.854 wt% and achieves an optimal ratio of 30 % when the sulfur addition is 3 %. Thermodynamic calculations, the X-ray diffraction (XRD), scanning electron microscope (SEM), and differential scanning calorimetry (DSC) analyses of the sample indicate that the formation of FeS can occur spontaneously in molten aluminum with the addition of sulfur. The mechanism of Fe-removing purification process was also discussed.