MELTING AND CASTING METHOD OF CAST ALUMINUM ALLOY

摘要

FIELD: metallurgy.;SUBSTANCE: invention relates to metallurgy of cast alloys based on aluminum and can be used for production of aluminum alloys based on Al-Si system additionally doped with magnesium, copper, manganese, strontium and other elements. Melting and casting method of foundry aluminum alloy containing from 5 to 22 wt% silicon and at least one metal selected from a group comprising iron, magnesium, manganese, strontium and copper, includes production of liquid ligature containing silicon in amount of 20–75 wt%, obtaining a molten aluminum alloy by mixing an aluminum melt, a ligature containing silicon, and solid components containing silicon and at least one element from a group comprising iron, magnesium, manganese, strontium and copper, and crystallization of molten aluminum alloy, wherein preparation of liquid ligature is performed by mixing molten aluminum with temperature of not higher than 860°C, containing boron from 0.0001 to 0.03 wt%, and molten silicon with temperature not lower than 1,440 °C, wherein mixing is carried out in at least 3 doses with successive increase in the concentration of silicon in the ligature melt, followed by holding ligature melt for at least 30 minutes, wherein the number of primary silicon crystals should not exceed more than 5 wt%, obtaining molten aluminum alloy of specified chemical composition is carried out by mixing aluminum melt with temperature equal to 700–860 °C, and a liquid ligature with silicon and boron, providing an amount of silicon in the melt of not less than 80 wt% of amount of silicon in obtained alloy, and melt crystallization is carried out at temperature higher than liquidus temperature of aluminum alloy by not less than 30 °C, to produce cast bars or pigs.;EFFECT: invention is aimed at increasing the melt preparation efficiency and obtaining a cast aluminum alloy structure with favorable morphology.;3 cl, 4 tbl, 3 ex