▎ 摘　　要

NOVELTY - Preparing modified graphene nano-sheet magnesium-aluminum material by interface optimization method, comprises e.g. pre-dispersing graphene nano-sheet in nitric acid solution and ultrasonicating, cooling, rinsing, centrifuging and drying, (ii) adding the graphene nano-sheets pretreated in step (i) in anhydrous ethanol solution and ultrasonicating, (iii) adding cerium nitrate to absolute ethanol to dissolve ultrasonically, (iv) adding urea crystals and glycerol to the graphene nano-sheet suspension obtained in step (iii) and ultrasonicating, (v) adding the graphene nano-sheet suspension treated in step (iv) into hydrothermal reactor and reacting to obtain prefabricated material powder, (vi) adding the obtained powder into corundum crucible then placing into a vacuum tube furnace, and roasting, (vii) adding the cerium oxide coated graphene nano-sheets and pure aluminum powder into ethanol to stirring to assist ultrasonic premixing to obtain mixed powder, and post-processing. USE - The method is useful for preparing modified graphene nano-sheet magnesium-aluminum material by interface optimization method. ADVANTAGE - The method: is simple and suitable for industrial production; improves utilization of the coating layer on the basis of improving wetting; alleviates the decline in corrosion resistance caused by the addition of carbon materials; and reduce the agglomeration of gold nano particles (GNPs) and able to better disperse the reinforcing phase. DETAILED DESCRIPTION - Preparing modified graphene nano-sheet magnesium-aluminum material by interface optimization method, comprises (i) pre-dispersing graphene nano-sheet in nitric acid solution having mass concentration of 99-99.999% and ultrasonicating at 60-80?Oc for 6-8 hours, cooling to room temperature, rinsing with deionized water to neutrality, centrifuging and drying in vacuum drying oven, (ii) adding the graphene nano-sheets pretreated in step (i) in anhydrous ethanol solution and ultrasonicating for 10-15 minute under ultrasonic power greater than or equal to 150 W, (iii) adding cerium nitrate to absolute ethanol to dissolve ultrasonically, where the molar ratio between cerium nitrate and absolute ethanol 1:5-1:8, then adding the solution dropwise to the ethanol solution of graphene nano-sheets obtained in step (ii) under continuous ultrasonic treatment, where the added amount of cerium nitrate is controlled according to the molar ratio of graphene nano-sheets to cerium nitrate of 1:0.35-1:0.85, completing the addition and continuously ultrasonicating for 3-5 hours, (iv) adding urea crystals and glycerol to the graphene nano-sheet suspension obtained in step (iii) and ultrasonicating for 10-30 minutes, where the molar ratio of graphene nano-sheets and urea is 1:0.7-1:1.6, and volume ratio between total solution and glycerol is 5:1-7:1, (v) adding the graphene nano-sheet suspension treated in step (iv) into hydrothermal reactor, where the volume of the suspension is 25-60% of the dissolved volume of the reactor, then sealing the reactor, then placing the reactor in furnace at 80-100 degrees C for 1-3 hours at a heating rate of 1-3 degrees C/seconds, and reacting at 150 degrees C for 2-6 hours at a heating rate of 3-5 degrees C/seconds, then taking out the reactor and maintaining in sealed state and air-cooling to room temperature, then centrifuging the solution to obtain precipitate, washing repeatedly with absolute ethanol and drying in vacuum oven to obtain prefabricated material powder, where the centrifugation speed is 7000-9000 revolutions/minute, (vi) adding the obtained powder into corundum crucible then placing into a vacuum tube furnace, and roasting at high temperature of 500-600 degrees C for 2-3 hours to obtain cerium oxide coated graphene nano-sheets, (vii) adding the cerium oxide coated graphene nano-sheets and pure aluminum powder into ethanol to stirring to assist ultrasonic premixing for 20-40 minutes, , and then vacuum drying to obtain mixed powder, where the addition amount of pure aluminum powder is 1-1.8 times of cerium oxide coated graphene nano-sheets; and the volume ratio between ethanol and composite powder is 1.5:1-1:1, (viii) introducing the mixed powder obtained in step (vii) into vacuum horizontal ball mill for ball milling, and filling the ball mill under argon for protection, where the molar ratio between ball and material is 6:1-10:1; ball milling time is 1-3 hours; and ball milling speed is 350-500 revolutions/minute, and then air cooling to room temperature in sealed state, (ix) placing the mixed powder obtained in step (viii) into corundum crucible and placing in tube furnace, heating in vacuum at 350-400 degrees C for 1-2hours to promote reaction, and then cooling the furnace to room temperature, (x) adding the magnesium alloy powder and the mixed powder obtained in step (ix) to vertical ball mill, where the amount of grinding balls is the total ball-to-material ratio of 6:1-10:1; graphene nano-sheets is 9-15% of the total mass of the material; ball mill is sealed and injected with argon for protection; ball milling time is 8-13 hours; speed is lower than 200 revolutions/minute in the first 2-5 hours, then increasing the speed to 300-500 revolutions/minute using intermittent ball milling each ball milling for 1-1.5 hours, continuing ball mill after cooling for 15-20 minutes, maintaining the temperature of the ball mill wall low until the ball milling process is completed, then sealing the ball mill and air cooling to room temperature, (xi) drying the mixed powder obtained in step (x) again in vacuum oven and placing in soft jacket and heating at 350-400 degrees C for direct hot extrusion to obtain bar material, where the extrusion ratio is 12-32, and the speed is greater than or equal to 8 mm/minute, (xii) melting the magnesium alloy block into semi-solid melt in vacuum furnace, and maintaining in solid phase rate of 6-10% and at a constant temperature for 20-25 minutes, then adding bar material obtained in step (xi) to the magnesium alloy semi-solid melt and applying to press the iron rod with release agent into the bottom an then dispersing by mobile ultrasonic probe, where the frequency is 20 KHz; power is 0.9-2.1 Kw; and move the probe every 1-3 minutes for a duration of 15-25 minutes under argon protection, and (xiii) maintaining the semi-solid melt treated in step (xii) in a state of magnetic stirring, and performing rheological die-casting treatment, where the punch injection speed is greater than or equal to 2.5 m/s and mold temperature is 200-280 degrees C, and die-casting into columnar material, where the casting temperature is 15-680 degrees C; thickness of the handle is 20-25mm; diameter of the hammer head is controlled to 60 mm; injection time is controlled to 3 seconds; cooling time is controlled to 2-3 seconds and mold retention time is controlled to 10-15 seconds.