Optimization of heat-treated silicon nitride additive parameters on flawless casting of AA7075 alloys: an alternative for conventional green sand

This study involved the fabrication of AA7075 metal castings utilizing an environmentally sustainable manufacturing sand contains novel Si3N4 additives within a sand mold. The AA 7075 castings, free of flaws, were produced using sand molds created from millet husk ash and heat treated Si3N4, with the different ratios of sand, additive, and water meticulously calibrated. The findings yield the subsequent definitive conclusions. An efficient substitute for commercial sand in the casting industry is the production of Si3N4 ultrafine particles utilizing byproducts from finger millet. The incorporation of heat-treated Si3N4 improved both solidification and heat removal management. In all nine scenarios, the cast samples display medium grains indicates retained ductility. The A12B1C2 experimental pattern offers the most potential for enhanced results. The confirmation test indicated that the freshly delivered GRG possesses a value of around 0.71 for the predominant process variable (A3B2C2). A reduction in vacancy to 0.38 and a decrease in defect rating to 3.51 result in an increase of 4.44 in GRG.