▎ 摘　　要

NOVELTY - Casting process for improving strength of 6-series aluminum alloy profile involves evacuating smelting furnace, filling with nitrogen gas, mixing metal raw material, heating and melting in smelting furnace, smelting, adding aluminum alloy inoculant, stirring and smelting to obtain melt, leaving still, cooling to obtain molten alloy mixture, subjecting molten alloy to homogenization treatment to obtain aluminum alloy slurry, using gradient heating method to increase the temperature to 800-850 degrees C, adding nano-silicon, nano-silicon nitride, nano-silicon boride, graphene and aluminum alloy inoculant, stirring, smelting, leaving still to obtain molten alloy liquid, cleaning mold, heating, pouring molten alloy liquid into mold and casting into cast aluminum alloy, air cooling cast aluminum alloy, gradually heating to 500-600 degrees C for 3-8 hours, cooling aluminum alloy to 80-90 degrees C for 3-20 hours, cooling to room temperature, demolding, removing blank, cutting into required shape and polishing. USE - Casting process for improving strength of 6-series aluminum alloy profile. ADVANTAGE - The method effectively improves strength, hardness, rigidity, corrosion resistance and fatigue performance of aluminum alloy and provides additional strengthening effect to aluminum alloy, uses trace amounts of scandium, cerium, zirconium, neodymium, zirconium, and manganese to forms composite strengthening phase in alloy which effectively inhibit recrystallization and improves the thermoplasticity and mechanical property of alloy due to use of rare earth elements which easily fill the surface defects of the aluminum phase. DETAILED DESCRIPTION - Casting process for improving strength of 6-series aluminum alloy profile involves evacuating smelting furnace and filling with nitrogen gas, mixing metal raw material, heating and melting at 750-850 degrees C in smelting furnace where temperature difference between the beginning and the end of the temperature gradient is 20-80 degrees C, smelting at 800-850 degrees C, adding aluminum alloy inoculant, stirring and smelting for 1-10 hours to obtain melt, leaving still for 5-10 hours, cooling to 650-750 degrees C by gradient cooling method to obtain molten alloy mixture where temperature difference between the beginning and the end of the temperature gradient is 20-50 degrees C, subjecting molten alloy to homogenization treatment for 3-10 hours to obtain aluminum alloy slurry, using gradient heating method to increase the temperature to 800-850 degrees C where temperature difference between the beginning and end of the temperature gradient is 20-50 degrees C, adding nano-silicon, nano-silicon nitride, nano-silicon boride, graphene and aluminum alloy inoculant, stirring, smelting for 2-5 hours until the melt is completely mixed, leaving still for 3-8 hours to obtain molten alloy liquid, cleaning mold, heating to 550-650 degrees C, cooling to 650-700 degrees C, pouring molten alloy liquid into mold and casting into cast aluminum alloy, air cooling cast aluminum alloy to 170-180 degrees C for 2-5 hours, gradually heating to 500-600 degrees C for 3-8 hours, using mist cooling method to cool aluminum alloy to 80-90 degrees C for 3-20 hours, cooling to room temperature, demolding aluminum alloy, removing blank, cutting into required shape and polishing. The 6-series aluminum alloy profile comprises 0.4-1.6 %mass magnesium, 0.6-1.7 %mass nano-silicon, 0.2-0.4 %mass manganese, 0.05-0.15 %mass zirconium, 0.03-0.09 %mass neodymium, 0.04-0.08 %mass vanadium, 0.05-0.08 %mass lanthanum, 0.2-0.5 %mass germanium, 0.5-0.9 %mass nano-silicon boride, 0.4-0.9 %mass nano-silicon nitride, 0.1-3 %mass nickel, 0.1-0.6 %mass titanium, 0.5-1.1 %mass iron, 0.1-0.5 %mass inoculant, 0.02-0.05 %mass ruthenium, 1.5-3.5 %mass graphene and balance aluminum.