Phase Evolution of β-Al5FeSi During Recycling of Al–Si–Fe Alloys by Mg Melt

Abstract

The recycling of aluminum materials is an important green initiative since it can avoid the need for primary metals and Al–Si–Fe is a typical scrap aluminum alloy. One key goal in recycling of Al–Si–Fe alloys is to reduce the Fe content via some techniques to separate Al and Fe. A proposed method to obtain this goal via introducing the Al–Si–Fe alloy into a Mg melt has been investigated in this work. A separation layer with gathered Fe-rich and Al-poor Fe3Al0.7Si0.3 particles was obtained at the bottom of the cooled ingot, indicating that β-Al5FeSi phase evolves into Fe3Al0.7Si0.3, and quantities of Al are released to the upper Mg matrix simultaneously. However, the evolution of Al3Fe by adding binary Al–Fe alloy into Mg melt is different. It is proposed that the element Si plays an important role in the phase evolution procedure, thus affecting the performance of this method.