Dissolution Rates of Manganese Alloying Elements in Aluminium

This technical report investigates the dissolution rates of various manganese alloying elements in aluminium. The study employs Laser-Induced Breakdown Spectroscopy (LIBS) to continuously monitor the chemistry of molten aluminium as different manganese compositions are introduced. The research outlines the factors affecting dissolution rates, including the melting temperatures of manganese, the presence of oxide layers, and the impact of effective stirring. The report details two models of dissolution: one governed by diffusive transport through a liquid boundary layer and the other by diffusion in a solid phase. The findings suggest that higher aluminium content in Al-Mn master alloys correlates with increased dissolution rates. The study also discusses the formation of intermetallic phases during the dissolution process and presents experimental methods used to analyze the dissolution behavior. The results are aimed at improving alloying practices in casting processes, particularly in optimizing manganese addition to aluminium melts.