▎ 摘　　要

NOVELTY - Graphene composite rare earth modified sub-eutectic aluminum-silicon-magnesium casting alloy comprises 4.5-10.5 wt.% silicon, 0.25-0.70 wt.% magnesium, 0.21-1.21 wt.% cerium, 0.05-0.20 wt.% titanium, 0.04-0.25 wt.% iron, 0.03-0.25 wt.% copper, 0.03-0.25 wt.% manganese, 0.00-0.25 wt.% chromium, 0.00-0.10 wt.% nickel, 0.00-0.35 wt.% zinc, 0.00-0.15 wt.% tin, 0.05-0.15 wt.% zirconium, 0.05-0.1 wt.% beryllium, 0.05-0.1 wt.% lead, 0.001-0.005 wt.% graphene, unspecified other impurity elements each less than or equal to 0.02 wt.%, total less than or equal to 0.10 wt.% and aluminum (remaining amount). USE - The graphene composite rare earth modified sub-eutectic aluminum-silicon-magnesium casting alloy is useful in the field of construction and in automobile wheels (all claimed). DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing graphene composite rare earth modified sub-eutectic aluminum-silicon-magnesium casting alloy, comprising: (i) taking aluminum particles, silicon particles, magnesium powder, cerium powder, titanium powder, iron powder, copper powder, manganese powder, chromium powder, nickel powder, zinc powder, tin powder, zirconium powder , beryllium powder, lead powder and graphene; (ii) spreading the graphene on the aluminum foil, injecting a small amount of high-purity alcohol, dissolving graphene in alcohol fully, adding the silicon particles, stirring uniformly, making silicon particles adhere to graphene, evaporating alcohol for 20-30 seconds and folding the aluminum foil to obtain an aluminum foil wrapped with graphene and silicon particles; (iii) placing one quarter -1/3 of aluminum particles into a melting crucible, covering the bottom of the crucible, placing the aluminum foil wrapped in graphene and silicon particles, placing other metal materials other than aluminum into the crucible and placing the remaining aluminum particles so that the aluminum particles completely cover other raw materials; (iv) placing the melting crucible into the melting furnace, closing the melting furnace door, vacuumizing, filling with high-purity argon to 450-500 Pa as a protective gas, turning on the heating power and heating to 700-720 degrees C to melt the aluminum particles completely, heating to 740-750 degrees C and shaking constantly the melting crucible to accelerate the homogenization of the alloy melt; and (v) stopping heating, cooling the alloy melt to 630-650 degrees C and casting the molten alloy into a graphite mold under an electric charge.