Elimination of Iron in Molten Aluminum Scrap by Electromagnetic Stirring Technique

Abstract

The present study is a way to effectively remove the impurities in the aluminum in the liquid state. Excessive iron forms needle-shaped AlFeSi intermetallic compounds, which cause the surface defects of aluminum extruded panels, results in the decreasing fluidity and ductility of the final product. As a common process, those compounds change from the needle-shaped to the globular-shaped alpha-AlFeMnSi intermetallic compounds through the addition of manganese to the aluminum melt. Those phases settle down during the solidification process, and then such is cut. Note, however, that the efficiency of iron elimination is very low. This study shows that electromagnetic stirring (EMS) technology can increase the efficiency of iron removal from the melts by reducing the time taken for the formation of intermetallic compounds. To investigate the effect on the efficiency of iron elimination in aluminum melt scrap, EMS current, holding temperature, and time of melt as well as the ratio of manganese to iron were controlled. As a result of this study, lower holding temperature and longer holding time of aluminum melt make iron elimination in aluminum melt more efficient with induced EMS.