Thermal analysis, microstructure and performance of AA6063 aluminum alloy casting with Ag and Fe additions

This article aims to investigate the microstructure, mechanical properties, wear and corrosion resistance of the grain refined AA6063 Aluminum Alloy Casting with added Ag and Fe. Thermal analysis was used to evaluate the influence of Ag and Fe addition. Reactions are observed during the solidification due to the formation of the alpha-Al dendritic network, followed by the precipitation of the Al8Fe2Si, transformation of Al8Fe2Si into Al5FeSi and/or precipitation of Al5FeSi intermetallic, and finally, the precipitation of small dark particles Mg2Si. Microstructure was examined using optical microscopy, Image analysis and scanning electron microscopy. Hardness, tensile properties, wear and corrosion resistance were evaluated for the as-cast conditions. Line scans for Ag, Fe, Si, Cu and Al were obtained from the various as cast samples using Energy-dispersive x-ray spectroscopy (EDX) facilities. The results reveal that different intermetallic phases can be formed. These phases are rich in Si, Fe, Mg and Ag. Additionally, AA6063 aluminum alloy casting with added 0.7-0.85 wt% Ag and 0.25-0.95 wt% Fe showed high wear and corrosion resistance response respectively. The wear and corrosion resistance of the AA6063 aluminum alloys with added Ag and Fe resulted were remarkably improved especially at 0.7 wt% Ag addition.