Preparation method of aluminum-based graphene composite material

Abstract

According to the preparation method of the aluminum-based graphene composite material, a zinc layer is evenly attached to the surface of an aluminum-graphene prefabricated body in advance, low-melting-point zinc liquid intrudes into graphene-aluminum interface gaps, the zinc layer is adopted as intermediate transition, interface reaction is avoided from generating an Al4C3 impurity phase, diffusion of zinc into an aluminum matrix enhances the interface bonding strength, and the aluminum-based graphene composite material is obtained. And finally, the high-strength and high-conductivity aluminum-based graphene composite material is prepared. According to the aluminum-graphene composite technology, the problems that graphene is prone to agglomeration and poor in conductivity are effectively solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of new materials, and in particular relates to a method for preparing an aluminum-based graphene composite material, and also relates to an aluminum-based graphene composite material. Background Art

[0002] With the development of society and the progress of science, the requirements for the performance of aluminum alloys are gradually increasing, especially in the field of structural and functional integrated materials. Materials need to meet not only strength requirements but also functional requirements. However, for aluminum alloys, strength and conductivity are often a pair of contradictions. Improving strength will weaken conductivity, and improving conductivity will lead to reduced strength. Composite materials are the best way to solve this contradiction. In recent years, the preparation of aluminum-graphene composite materials has become a feature of domestic and foreign researchers. Therefore, the mass preparation of high-performance, low-cost aluminum-graphene composite materials is of great scientific significance for the development of a new generation of high-strength and high-conductivity aluminum alloys.

[0003] Chinese invention patent CN114260068A discloses a method for preparing a high thermal conductivity aluminum-based graphene composite material: immerse the aluminum sheet vertically in a dopamine aqueous solution with a pH of 8 to 8.5, and let it react for 20 to 80 minutes; after taking the aluminum sheet out of the dopamine aqueous solution, wash it with water with a purity not less than distilled water, and then immerse the washed aluminum sheet vertically in a graphene oxide aqueous solution, and let it react for 2 to 6 hours; after taking the aluminum sheet out of the graphene oxide aqueous solution, wash it with water with a purity not less than distilled water, and then put the washed aluminum sheet into 100 to 300°C for annealing treatment, the annealing time is 0.5 to 3 hours, and the high thermal conductivity aluminum-based graphene composite material is obtained. The method described in the invention is simple in process and the instrument and equipment are easy to operate; the prepared aluminum-based graphene composite material has excellent thermal conductivity.

[0004] Chinese invention patent CN104862508A discloses a method for preparing an aluminum-based graphene composite material: graphene is mixed with an alcohol solution, and aluminum alloy powder is added after ultrasonic oscillation and mechanical ball milling is performed. After the ball milling is completed, the mixed solution is dried to obtain a graphene / aluminum alloy composite powder, and a dense graphene / aluminum alloy composite prefabricated ingot is obtained by hot isostatic pressing. The same grade of aluminum alloy is melted in a crucible at a temperature of 30 to 80 ° C above the melting point of the aluminum alloy, and the prefabricated ingot is remelted into the aluminum alloy melt, and then quickly cast into a graphite mold after stirring to obtain an aluminum-based graphene composite ingot. The aluminum-based graphene composite ingot is homogenized, and the process system is 495 ° C ± 5 ° C, and the heat preservation is 24 hours, and the aluminum-based graphene composite rod or plate is prepared by hot extrusion or rolling molding. The patent first prepares a graphene / aluminum alloy composite prefabricated ingot; then the prefabricated ingot is added to the aluminum alloy melt for remelting and a casting process is used to obtain an aluminum-based graphene composite ingot; finally, the ingot is homogenized, and then a high-strength aluminum-based graphene composite rod or plate is obtained by a molding process such as hot extrusion or rolling. The invention method solves the problem of the composite and homogenization of graphene and aluminum alloy, and can accurately adjust the amount of graphene added to the composite material. The preparation method is simple and efficient, and it is easy to achieve large-scale industrialization.

[0005] Chinese invention patent CN104846230A discloses a method for preparing an aluminum-based graphene composite material, which specifically includes the following steps: 1) dispersing graphene in an organic solvent to form a graphene dispersion liquid, wherein the organic solvent is an organic solvent that does not chemically react with aluminum; 2) acidifying the interconnected pore foam aluminum to remove the oxide layer on the surface and then drying it; 3) soaking the interconnected pore foam aluminum treated in step 2) in the graphene dispersion liquid, then taking it out, and drying it to obtain a graphene / foam aluminum composite; 4) preheating the graphene / foam aluminum composite, and then rolling and forming it to finally obtain an aluminum-based graphene composite material, wherein step 1) and step 2) are not in any particular order, and the mass of graphene and interconnected pore foam aluminum is 0.1wt%-10wt%; the process avoids the destruction of graphene by high-energy ball milling in traditional powder metallurgy process, and can achieve its effective dispersion with foam aluminum as the skeleton, and the process is simple, with significant industrial application prospects.

[0006] Chinese invention patent CN117086308A discloses an aluminum-based graphene composite material with a hollow cubic structure and a titanium alloy-graphene composite material for SLM. The prepared aluminum-based Al-plated graphene nanosheets are used as a template to prepare an aluminum-based graphene oxide composite material with a hollow cubic structure, and then ball-milled with a titanium alloy to prepare a titanium alloy-graphene composite material for SLM. The preparation method of the invention effectively improves the dispersibility of graphene in titanium alloy, enhances the interface bonding strength between the graphene nanosheets and the titanium alloy matrix, better utilizes the lateral performance of the graphene nanosheets, and avoids the problem of graphene nanosheets decomposing and forming harmful phases during the composite process with the titanium alloy metal matrix. Each face of the hollow cubic structure is composed of aluminum-based Al-plated graphene nanosheets.

[0007] At present, high-energy ball milling, particle surface modification, liquid phase powder mixing and other processes are basically used to achieve uniform dispersion of graphene. These conventional process methods have low production efficiency and cannot effectively solve the problems of easy agglomeration and poor conductivity of graphene, which limits the industrialization of aluminum-graphene composite materials.

[0008] Based on this, it is necessary to provide a method for preparing an aluminum-based graphene composite material. The present invention develops a new graphene-aluminum composite process based on the combination of powder metallurgy and casting technology, and successfully prepares an aluminum-based graphene composite material with high strength and high conductivity. Summary of the invention

[0009] The purpose of the present invention is to provide a method for preparing an aluminum-based graphene composite material, so as to solve the shortcomings of the prior art aluminum-based graphene composite material that graphene is easy to agglomerate and has weak electrical conductivity.

[0010] The invention also provides an aluminum-based graphene composite material.

[0011] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0012] A method for preparing an aluminum-based graphene composite material comprises the following steps:

[0013] S1, cold-pressing the composite powder of graphene and aluminum using a mold to obtain an aluminum-graphene preform;

[0014] S2, smelting pure zinc to obtain a zinc melt, cooling it to a semi-solid state, dipping the aluminum-graphene preform in the pure zinc melt, so that the zinc melt evenly covers the aluminum-graphene preform to obtain an aluminum-graphene-zinc intermediate;

[0015] S3, placing the aluminum-graphene-zinc intermediate in a casting mold for preheating, pouring aluminum alloy melt, performing pressure holding treatment, and molding to obtain an aluminum-based graphene composite material.

[0016] The method for preparing an aluminum-based graphene composite material of the present invention opens stacked graphene sheets without destroying the spatial structure of graphene, thereby realizing high-quality composite of graphene-aluminum. Due to the mismatch of surface tension and poor wettability between aluminum and graphene, the interface bonding is weak and the overall performance of the composite material is poor. The present invention preliminarily uniformly attaches a zinc layer on the surface of an aluminum-graphene preform, and uses a low-melting-point zinc liquid to invade the graphene-aluminum interface gap, thereby solving the problem of poor wettability between aluminum and carbon and strengthening the interface bonding strength of graphene and aluminum. In order to make the zinc layer uniformly coat the aluminum-graphene preform, the zinc is first smelted, and after the zinc melt is cooled to a semi-solid state, multiple dipping is performed. When the aluminum alloy is die-casted, the low-melting-point zinc layer on the surface first contacts the high-temperature melt and melts, and the zinc liquid infiltrates the thin sheet preform under pressure and gradually invades the interface gap. By using the zinc layer as an intermediate transition, the interface reaction is avoided to generate an Al4C3 impurity phase, and the diffusion of zinc into the aluminum matrix can also strengthen the interface bonding strength. In addition, there are pores inside the sintered composite material, and the flowing zinc liquid and aluminum alloy melt can fill the voids to improve the density and overall performance of the composite material.

[0017] In the present invention, the mass fraction of graphene in the composite powder of graphene and aluminum in S1 is 0.2-1wt%.

[0018] In the present invention, the composite powder of graphene and aluminum is prepared by a batch ball milling powder mixing process.

[0019] Furthermore, the specific process of the batch ball milling powder mixing process is as follows: aluminum powder and graphene are mixed to make a mixed powder; the mixed powder and aluminum powder are placed in a corundum ball mill for ball milling respectively, and then the two powders after ball milling are mixed and further ball milled to obtain a composite powder of graphene and aluminum. The present invention adopts a batch ball milling powder mixing process, and the refined aluminum powder is mixed with the composite powder and further ball milled, so that the graphene can achieve the best dispersion effect in the aluminum powder. After ball milling and refinement, the surface of the aluminum powder has a positive charge, and the graphene attached to the surface of the composite powder has a negative charge. The electrostatic attraction between the different charges causes the graphene flakes to peel off, which improves the dispersion effect of the graphene in the aluminum powder. The electrostatic adsorption between the positive and negative particles can be completed within a few minutes, and this dispersion process can be carried out spontaneously without any chemical reagents, avoiding the problem that the residual surfactant is not easy to handle.

[0020] Furthermore, the ball mill speed is 300-350 r / min, the ball-to-material ratio is 3.5-5:1, and the vacuum degree is 10 -3 ~10 - 4 MPa.

[0021] In the present invention, the ball milling process adopts an intermittent ball milling process, and the machine is stopped for 10 to 15 minutes every 20 to 25 minutes of ball milling. Since the melting point of aluminum powder is 660°C, the temperature rise during the ball milling process will cause the aluminum particles to cold weld and agglomerate. The intermittent ball milling can avoid the coarsening of the powder particles.

[0022] In the present invention, zirconium oxide grinding balls are used to prevent the surface of the grinding balls from transferring electrons and adsorbing graphene during the ball milling process. In order to obtain the best ball milling effect, among the zirconium oxide grinding balls, the large balls with a diameter of 8 mm account for 20% of the total weight of the grinding balls, the medium balls with a diameter of 5 mm account for 50% of the total weight of the grinding balls, and the small balls with a diameter of 3 mm account for 30% of the total weight of the grinding balls.

[0023] In the present invention, the cold pressing in S1 is performed under a cold isostatic pressing pressure of 60 to 80 MPa and the pressure is maintained for 8 to 10 minutes.

[0024] The present invention adopts a new graphene aluminum-based composite casting process, and introduces graphene into the aluminum alloy melt through an aluminum-graphene prefabricated block to improve the dispersion effect and distribution form of graphene in the aluminum matrix. Due to the large difference in the surface energy of the two materials, graphene is very easy to agglomerate in the aluminum melt. The traditional stirring casting method directly adds graphene into the molten aluminum liquid, and graphene is easy to float on the surface of the melt and react with the high-temperature melt to generate an impurity phase. The present invention introduces a graphene reinforcement phase into the high-temperature melt with the help of an aluminum-graphene-zinc intermediate, avoids direct contact between graphene and the non-wetting aluminum alloy melt, inhibits the floating and agglomeration of graphene in the melt, improves the melting effect of graphene in the aluminum alloy melt, and achieves uniform dispersion. When pouring the aluminum alloy melt, pour it slowly from one side of the intermediate to avoid the intermediate being impacted by the high-temperature melt, causing the surface zinc liquid to be lost. In order to further alleviate the deterioration of electrical and thermal conductivity caused by the interface reaction between graphene and aluminum, a water-cooled mold can be used. The high-temperature aluminum alloy melt is rapidly solidified into a shell under the forced cooling effect of cooling water, preventing graphene from forming an impurity phase with aluminum in a high-temperature environment for a long time. The novel casting process of the present invention successfully introduces a graphene-enhanced phase into the aluminum alloy, achieving excellent mechanical properties while improving its electrical conductivity.

[0025] In the present invention, the smelting temperature of pure zinc in S2 is 450-480°C.

[0026] In the present invention, the preheating in S3 is to a temperature of 150-200°C.

[0027] In the present invention, the pressure-maintaining treatment in S3 is to apply a pressure of 10 to 20 MPa and maintain the pressure for 2 to 5 minutes.

[0028] An aluminum-based graphene composite material is prepared by the method.

[0029] The present invention has the following beneficial effects:

[0030] (1) The method for preparing an aluminum-based graphene composite material of the present invention comprises the following steps: a zinc layer is uniformly attached to the surface of an aluminum-graphene preform in advance, a low-melting-point zinc liquid is used to invade the graphene-aluminum interface gap, and the zinc layer is used as an intermediate transition to avoid the generation of Al4C3 impurity phase by interface reaction. The diffusion of zinc into the aluminum matrix strengthens the interface bonding strength, and finally a high-strength and high-conductivity aluminum-based graphene composite material is prepared.

[0031] (2) The present invention uses the zinc layer as an intermediate transition to achieve stable composite of aluminum matrix and graphene without agglomeration of graphene, and can be used to mass-produce high-performance, low-cost aluminum-graphene composite materials. The graphene in the composite material has a high degree of dispersion and good distribution morphology, and has the potential to be a new generation of high-strength and high-conductivity aluminum alloy. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a SEM image of the preform of the present invention. DETAILED DESCRIPTION

[0033] The technical solution of the present invention is further described below in conjunction with specific embodiments so that those skilled in the art can better understand and implement the technical solution of the present invention.

[0034] Example 1

[0035] A method for preparing an aluminum-based graphene composite material comprises the following steps:

[0036] S1, cold-pressing the composite powder of graphene and aluminum using a mold to obtain an aluminum-graphene preform;

[0037] The specific process is as follows: weigh 0.1g of graphene nanosheets and 49.9g of high-purity aluminum powder, mix the graphene with 20g of aluminum powder and pour into a corundum ball mill, and place the remaining aluminum powder in another ball mill. Mill for 120 minutes, take out the two powders and mix them, and continue to mill for 90 minutes. Before ball milling, evacuate the tank to reduce oxidation, and the vacuum degree is 10 -3 MPa, ball-to-material ratio of 5:1, speed of 300r / min, intermittent ball milling, stop for 20min for heat dissipation after every 10min of ball milling, and obtain graphene aluminum composite powder after ball milling. Take 4g of the completely mixed composite powder and pour it into a cemented carbide mold, press it into an Al-0.2wt% GNPs preform with a press, the pressure parameter is 60MPa, keep the pressure for 8min, and demold to obtain a thin sheet of aluminum-graphene preform. The preform is roughly ground and polished, and placed in a vacuum box for standby.

[0038] In this embodiment, zirconium oxide grinding balls are used to prevent the surface of the grinding balls from transferring electrons and adsorbing graphene during the ball milling process. In order to obtain the best ball milling effect, among the zirconium oxide grinding balls, the large balls with a diameter of 8 mm account for 20% of the total weight of the grinding balls, the medium balls with a diameter of 5 mm account for 50% of the total weight of the grinding balls, and the small balls with a diameter of 3 mm account for 30% of the total weight of the grinding balls.

[0039] S2, smelting pure zinc to obtain a zinc melt, cooling it to a semi-solid state, dipping the aluminum-graphene preform in the pure zinc melt, so that the zinc melt evenly covers the aluminum-graphene preform to obtain an aluminum-graphene-zinc intermediate;

[0040] The specific process is as follows: pure zinc is placed in a crucible, smelted and kept warm at 460°C to obtain a pure zinc melt. After the pure zinc melt is cooled to a semi-solid state, the aluminum-graphene preform is placed in the zinc melt under a high-purity argon protective atmosphere for dipping, so that the zinc melt evenly covers the aluminum-graphene preform to obtain an aluminum-graphene-zinc intermediate.

[0041] S3, placing the aluminum-graphene-zinc intermediate in a casting mold for preheating, pouring aluminum alloy melt, performing pressure holding treatment, and molding to obtain an aluminum-based graphene composite material.

[0042] The specific process is as follows: Graphene-enhanced aluminum-based composite materials are prepared by melt casting. The aluminum alloy matrix is ​​pre-melted in a medium-frequency induction furnace at a melting temperature of 800°C. The aluminum-graphene-zinc intermediate is then preheated to 200°C and placed in a mold. The aluminum alloy melt is slowly cast from one side of the intermediate under a protective atmosphere. The pressure head is covered and a pressure of 15MPa is applied. The pressure is maintained for 3 minutes, and the aluminum-based graphene composite material with a mass fraction of 0.2wt% is obtained by solidification.

[0043] Example 2

[0044] A method for preparing an aluminum-based graphene composite material comprises the following steps:

[0045] S1, cold-pressing the composite powder of graphene and aluminum using a mold to obtain an aluminum-graphene preform;

[0046] The specific process is as follows:

[0047] Weigh 0.25g of graphene nanosheets and 49.75g of high-purity aluminum powder, mix the graphene with 20g of aluminum powder and pour into a corundum ball mill. Place the remaining aluminum powder in another ball mill. Mill for 130 minutes, take out the two powders and mix them, and continue to mill for 70 minutes. Before ball milling, evacuate the tank to reduce oxidation, and the vacuum degree is 10 -3MPa, the ball-to-material ratio is 5:1, the speed is 300r / min, and intermittent ball milling is used. After each 10min of ball milling, the machine is stopped for 20min for heat dissipation. After the ball milling is completed, graphene aluminum composite powder is obtained. 4g of the completely mixed composite powder is poured into a cemented carbide mold and pressed into an Al-0.5wt% GNPs preform with a press. The pressure parameter is 70MPa, and the pressure is maintained for 8min. The aluminum-graphene preform in a thin sheet shape is demolded. The preform is roughly ground and polished, and placed in a vacuum box for standby use.

[0048] In this embodiment, zirconium oxide grinding balls are used to prevent the surface of the grinding balls from transferring electrons and adsorbing graphene during the ball milling process. In order to obtain the best ball milling effect, among the zirconium oxide grinding balls, the large balls with a diameter of 8 mm account for 20% of the total weight of the grinding balls, the medium balls with a diameter of 5 mm account for 50% of the total weight of the grinding balls, and the small balls with a diameter of 3 mm account for 30% of the total weight of the grinding balls.

[0049] S2, smelting pure zinc to obtain a zinc melt, cooling it to a semi-solid state, dipping the aluminum-graphene preform in the pure zinc melt, so that the zinc melt evenly covers the aluminum-graphene preform to obtain an aluminum-graphene-zinc intermediate;

[0050] The specific process is as follows: pure zinc is placed in a crucible, smelted and kept warm at 470°C to obtain a pure zinc melt. After the pure zinc melt is cooled to a semi-solid state, the aluminum-graphene preform is placed in the zinc melt under a high-purity argon protective atmosphere for dipping, so that the zinc melt evenly covers the aluminum-graphene preform to obtain an aluminum-graphene-zinc intermediate.

[0051] S3, placing the aluminum-graphene-zinc intermediate in a casting mold for preheating, pouring aluminum alloy melt, performing pressure holding treatment, and molding to obtain an aluminum-based graphene composite material.

[0052] The specific process is as follows: Graphene-enhanced aluminum-based composite materials are prepared by melt casting. The aluminum alloy matrix is ​​pre-melted in a medium-frequency induction furnace at a melting temperature of 790°C. The aluminum-graphene-zinc intermediate is then preheated to 180°C and placed in a mold. The aluminum alloy melt is slowly cast from one side of the intermediate under a protective atmosphere. The pressure head is covered and a pressure of 20MPa is applied. The pressure is maintained for 3 minutes, and the aluminum-based graphene composite material with a mass fraction of 0.5wt% is obtained by solidification.

[0053] Example 3

[0054] A method for preparing an aluminum-based graphene composite material comprises the following steps:

[0055] S1, cold-pressing the composite powder of graphene and aluminum using a mold to obtain an aluminum-graphene preform;

[0056] The specific process is as follows: weigh 0.1g of graphene nanosheets and 49g of high-purity aluminum powder, mix the graphene with 20g of aluminum powder and pour into a corundum ball mill, put the remaining aluminum powder in another ball mill, mill for 150min, take out the two powders and mix them, and continue to mill for 90min. Before ball milling, evacuate the tank to reduce oxidation, and the vacuum degree is 10 -3 MPa, ball-to-material ratio of 5:1, speed of 300r / min, intermittent ball milling, stop for 20min for heat dissipation after every 10min of ball milling, and obtain graphene aluminum composite powder after ball milling. Take 4.5g of the completely mixed composite powder and pour it into a cemented carbide mold, press it into an Al-1wt% GNPs preform with a press, the pressure parameter is 80MPa, keep the pressure for 10min, and demold to obtain a thin sheet of aluminum-graphene preform. The preform is roughly ground and polished, and placed in a vacuum box for standby.

[0057] In this embodiment, zirconium oxide grinding balls are used to prevent the surface of the grinding balls from transferring electrons and adsorbing graphene during the ball milling process. In order to obtain the best ball milling effect, among the zirconium oxide grinding balls, the large balls with a diameter of 8 mm account for 20% of the total weight of the grinding balls, the medium balls with a diameter of 5 mm account for 50% of the total weight of the grinding balls, and the small balls with a diameter of 3 mm account for 30% of the total weight of the grinding balls.

[0058] S2, smelting pure zinc to obtain a zinc melt, cooling it to a semi-solid state, dipping the aluminum-graphene preform in the pure zinc melt, so that the zinc melt evenly covers the aluminum-graphene preform to obtain an aluminum-graphene-zinc intermediate;

[0059] The specific process is as follows: pure zinc is placed in a crucible, smelted and kept warm at 470°C to obtain a pure zinc melt. After the pure zinc melt is cooled to a semi-solid state, the aluminum-graphene preform is placed in the zinc melt under a high-purity argon protective atmosphere for dipping, so that the zinc melt evenly covers the aluminum-graphene preform to obtain an aluminum-graphene-zinc intermediate.

[0060] S3, placing the aluminum-graphene-zinc intermediate in a casting mold for preheating, pouring aluminum alloy melt, performing pressure holding treatment, and molding to obtain an aluminum-based graphene composite material.

[0061] The specific process is as follows: Graphene-enhanced aluminum-based composite materials are prepared by melt casting. The aluminum alloy matrix is ​​pre-melted in a medium-frequency induction furnace at a melting temperature of 760°C. The aluminum-graphene-zinc intermediate is then preheated to 200°C and placed in a mold. The aluminum alloy melt is slowly cast from one side of the intermediate under a protective atmosphere. The pressure head is covered and a pressure of 10MPa is applied. The pressure is maintained for 5 minutes. After solidification and molding, an aluminum-based graphene composite material with a mass fraction of 1wt% is obtained.

[0062] Performance Testing

[0063] 1. Structural detection of aluminum-graphene preform

[0064] The SEM conditions of the aluminum-graphene preform prepared in Example 1 of the present invention are detected. Figure 1 As shown, it can be seen that aluminum and graphene are evenly distributed and have good density.

[0065] 2. Effects of different graphene contents on the mechanical and electrical properties of composite materials

[0066] The yield strength, tensile strength and electrical conductivity of the aluminum-based graphene composite materials prepared in Examples 1-3 were tested respectively. The specific results are shown in Table 1.

[0067] Table 1 Effects of different graphene contents on the mechanical and electrical properties of composite materials

[0068] sample Yield strength (MPa) Tensile strength(MPa) Electrical conductivity (%) Example 1 132 210 65.4 Example 2 145 235 66.5 Example 3 153 241 66.9

[0069] The present invention prepares a high-performance aluminum-based graphene composite material by powder metallurgy combined with liquid casting. The graphene content and distribution morphology are flexibly regulated by the powder metallurgy process to ensure the electrical and thermal properties of the composite material. Through pressure casting treatment, the aluminum and graphene interface is filled with low-melting-point zinc liquid to achieve a stable composite of aluminum and carbon. Finally, the intermediate is coated with an aluminum alloy with excellent mechanical properties, and a high-strength and high-conductivity aluminum-based composite material with a unique "sandwich" structure is successfully prepared.

[0070] The above embodiments of the present invention are not intended to limit the protection scope of the present invention, and the implementation modes of the present invention are not limited thereto. All other modifications, replacements or changes made to the above structures of the present invention based on the above contents of the present invention, in accordance with common technical knowledge and customary means in the art, without departing from the above basic technical ideas of the present invention, should fall within the protection scope of the present invention.

Claims

1. A method for preparing an aluminum-based graphene composite material, characterized in that: The following steps are involved: S1, cold-pressing the composite powder of graphene and aluminum using a mold to obtain an aluminum-graphene preform; S2, smelting pure zinc to obtain a zinc melt, cooling it to a semi-solid state, dipping the aluminum-graphene preform in the pure zinc melt, so that the zinc melt evenly covers the aluminum-graphene preform to obtain an aluminum-graphene-zinc intermediate; S3, placing the aluminum-graphene-zinc intermediate in a casting mold for preheating, pouring aluminum alloy melt, performing pressure holding treatment, and molding to obtain an aluminum-based graphene composite material.

2. The method for preparing the aluminum-based graphene composite material according to claim 1, characterized in that: The mass fraction of graphene in the composite powder of graphene and aluminum in S1 is 0.2 to 1 wt%.

3. The method for preparing the aluminum-based graphene composite material according to claim 1, characterized in that: The composite powder of graphene and aluminum is prepared by a batch ball milling powder mixing process, and the specific process of the batch ball milling powder mixing process is as follows: aluminum powder and graphene are mixed to prepare mixed powder; the mixed powder and aluminum powder are respectively placed in a corundum ball mill for ball milling, and then the two powders after ball milling are mixed and continued to be ball milled to obtain the composite powder of graphene and aluminum.

4. The method for preparing the aluminum-based graphene composite material according to claim 3, characterized in that: The ball mill speed is 300-350r / min, the ball-to-material ratio is 3.5-5:1, and the vacuum degree is 10 -3 ~10 -4 MPa.

5. The method for preparing the aluminum-based graphene composite material according to claim 3, characterized in that: The ball milling process adopts intermittent ball milling technology, with a stop time of 10 to 15 minutes after every 20 to 25 minutes of ball milling.

6. The method for preparing the aluminum-based graphene composite material according to claim 1, characterized in that: In S1, the cold pressing is performed under a cold isostatic pressing pressure of 60 to 80 MPa and the pressure is maintained for 8 to 10 minutes.

7. The method for preparing the aluminum-based graphene composite material according to claim 1, characterized in that: In S3, the temperature is preheated to 150-200°C.

8. The method for preparing the aluminum-based graphene composite material according to claim 7, characterized in that: The pressure holding treatment in S3 is to apply a pressure of 10 to 20 MPa and hold the pressure for 2 to 5 minutes.

9. An aluminum-based graphene composite material, characterized in that: The method is prepared by any one of claims 1 to 8.

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