Graphene nanoplatelet composite aluminum-based material and method of making

Abstract

This invention discloses a graphene nanosheet composite aluminum-based material, comprising: adding copper-plated graphene nanosheets to an aluminum-based melt, wherein the proportion of copper-plated graphene nanosheets added is 0.1%-1.0%; the copper-plated graphene nanosheets are graphene nanosheets with a copper atom coating formed on their surface. This invention also discloses its preparation method. The graphene nanosheets with added chemical copper plating produced by this invention can effectively improve the tensile strength and elongation (mechanical properties) of test bars, and have a significant effect on improving the performance of aluminum alloy materials.

Description

Technical Field

[0001] This invention relates to the field of composite aluminum-based material manufacturing, specifically to a graphene nanosheet composite aluminum-based material and its preparation method. Background Technology

[0002] Aluminum alloys are widely used in aerospace, automotive, and construction industries due to their excellent lightweight properties and good machinability.

[0003] However, there is still room for improvement in the strength and corrosion resistance of existing aluminum alloys. Graphene, as a novel nanomaterial, possesses extremely high strength, excellent electrical and thermal conductivity, and has attracted widespread attention in recent years. Adding specially treated graphene nanosheets to aluminum alloys is expected to overcome the performance limitations of existing aluminum alloys in terms of mechanical strength and corrosion resistance.

[0004] In the traditional process of combining graphene nanosheets with aluminum-based materials, the poor wettability between the nanosheets and the aluminum alloy, and the agglomeration of the nanosheets in the melt due to van der Waals forces, result in poor composite effect and fail to stably improve the mechanical properties and corrosion resistance of the aluminum alloy. Summary of the Invention

[0005] The purpose of this invention is to provide a graphene nanosheet composite aluminum-based material and its preparation method. By adding specially treated graphene nanosheets to aluminum alloys, the mechanical properties and corrosion resistance of the aluminum alloys can be improved.

[0006] The graphene nanosheets described in this patent, after chemical modification and surface alteration, can better bond with the aluminum matrix, thereby improving the mechanical properties and corrosion resistance of the composite material. Specifically, the addition of graphene can improve the grain structure of the aluminum alloy, reduce the grain size, and directly incorporate a reinforcing phase, playing a role in orovan strengthening and load transfer strengthening, thereby increasing its tensile strength and elongation.

[0007] Adding specially treated graphene nanosheets to aluminum alloys significantly improves their mechanical properties. By incorporating graphene nanosheets into aluminum alloys, this invention enhances the alloy's strength, toughness, corrosion resistance, and thermal conductivity, making it suitable for applications in aerospace, automotive, and electronic equipment.

[0008] To achieve the above objectives, the technical solution of the present invention is as follows:

[0009] A graphene nanosheet composite aluminum-based material, comprising:

[0010] Copper-plated graphene nanosheets are added to an aluminum-based melt, wherein the proportion of copper-plated graphene nanosheets added is 0.1%-1.0%.

[0011] The copper-plated graphene nanosheets are graphene nanosheets with a copper atom plating layer formed on the surface of the graphene nanosheets.

[0012] In a preferred embodiment of the present invention, the aluminum-based melt is obtained by melting an AlSi9Cu3 alloy.

[0013] In a preferred embodiment of the present invention, the AlSi9Cu3 alloy specifically comprises:

[0014] 8.5-10% by weight of Si;

[0015] Fe less than or equal to 1 weight percentage;

[0016] 2.1-4.0% Cu by weight;

[0017] Mn less than or equal to 0.5% by weight;

[0018] 0.2-0.55% by weight of Mg;

[0019] Less than or equal to 1.2% by weight of Zn, with the remainder being Al.

[0020] In a preferred embodiment of the present invention, the copper-plated graphene nanosheets are prepared by the following method:

[0021] Graphene nanosheets were added to a solution containing hexadecyltrimethylammonium chloride (CTAB) and copper sulfate, and stirred to uniformly disperse the graphene nanosheets.

[0022] An aqueous solution of reducing agent is added dropwise to the dispersion system, causing copper ions to be reduced and deposited on the surface of graphene nanosheets, forming a copper atom coating.

[0023] In a preferred embodiment of the present invention, the reducing agent is sodium borohydride, and the concentration of the sodium borohydride aqueous solution is 0.1-0.15 mol / L.

[0024] In a preferred embodiment of the present invention, the dropping rate of the aqueous solution of the reducing agent is 1-2 mL / min.

[0025] In a preferred embodiment of the present invention, the concentration of hexadecyltrimethylammonium chloride (CTAB) in the solution of hexadecyltrimethylammonium chloride (CTAB) is 0.1-0.5 mol / L, and the concentration of copper sulfate is 0.05-0.1 mol / L.

[0026] A method for preparing a graphene nanosheet composite aluminum-based material includes:

[0027] Graphene nanosheets were added to a solution containing hexadecyltrimethylammonium chloride (CTAB) and copper sulfate, and stirred to uniformly disperse the graphene nanosheets.

[0028] An aqueous solution of reducing agent is added dropwise to the dispersion system, causing copper ions to be reduced and deposited on the surface of graphene nanosheets, forming a copper atom coating.

[0029] Copper-plated graphene nanosheets are added to an aluminum-based melt, wherein the proportion of copper-plated graphene nanosheets added is 0.1%-1.0%.

[0030] The beneficial effects of this invention are as follows:

[0031] Through numerous experiments, the inventors of this invention discovered that the optimal addition ratio of graphene nanosheets is 0.1%-1.0%, within which the mechanical properties of aluminum alloys can be significantly improved while maintaining reasonable addition costs.

[0032] The treated graphene nanosheets were thoroughly mixed with aluminum alloy melt using a melting-casting method, then cast into shape, and finally subjected to appropriate heat treatment to optimize material properties.

[0033] Because this invention adopts a novel process route for aluminum-based composite graphene materials, it can complete the preparation of graphene nanosheet composite aluminum-based materials at a lower cost, overcoming the process difficulty of agglomeration when graphene is added to aluminum alloy melt. Attached Figure Description

[0034] The present invention will be further described in detail below with reference to the accompanying drawings.

[0035] Appendix Figure 1 This is a schematic diagram of the core process of the present invention.

[0036] Appendix Figure 2 This is a schematic diagram of the comparative stress-strain curve of the present invention.

[0037] Appendix Figure 3 This is a schematic diagram of the stress-strain curve in an embodiment of the present invention. Detailed Implementation

[0038] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0039] The AlSi9Cu3 alloy used in this patent is based on weight and includes: 8.5-10% Si (silicon), less than or equal to 1% Fe (iron), 2.1-4.0% Cu (copper), less than or equal to 0.5% Mn (manganese), 0.2-0.55% Mg (magnesium), and less than or equal to 1.2% Zn (zinc).

[0040] Pretreatment and activation of graphene nanosheets

[0041] Using an analytical balance with an accuracy of 0.1 mg, accurately weigh 100 mg of few-layer graphene nanosheets. Add them to a three-necked flask containing 200 mL of a 0.1 mol / L aqueous solution of hexadecyltrimethylammonium chloride (CTAC). Then, using a pipette, add 10 mL of a 0.05 mol / L copper sulfate (CuSO4) solution to the mixture. Place the flask on a magnetic stirrer and stir continuously at 500 rpm at room temperature for 10 minutes to ensure that the graphene nanosheets are fully wetted, dispersed, and that initial adsorption of copper ions is achieved.

[0042] Chemical copper plating process

[0043] Maintaining the stirring of the above mixture (300 rpm), a freshly prepared 0.1 mol / L sodium borohydride (NaBH4) aqueous solution was slowly added dropwise to the flask at a rate of ~2 mL / min using a constant-pressure dropping funnel. This process was carried out at room temperature, utilizing the strong reducing properties of sodium borohydride to reduce the copper ions (Cu²⁺) adsorbed on the surface of the graphene nanosheets to elemental copper (Cu). 0 The copper plating is uniformly deposited on the surface of the nanosheets, forming a dense copper plating layer. After the addition is complete, the reaction is stirred for another 30 minutes to ensure complete reduction.

[0044] Preparation of aluminum substrate materials

[0045] First, the AlSi9Cu3 alloy ingot is melted at 700°C using a pit furnace. The AlSi9Cu3 alloy ingot is then placed in a graphite crucible preheated to 500-600°C and placed in a crucible resistance furnace, heated to 700°C ± 10°C to fully melt it into a homogeneous melt. Next, refining is performed at 720-750°C: 0.3% anhydrous hexachloroethylammonium (C2Cl6) by weight of the melt is pressed into the bottom of the melt using a bell jar, causing the bubbles generated by its decomposition to rise to the surface, thus removing dissolved hydrogen and suspended inclusions. After refining, the melt is allowed to stand for 5-10 minutes, and the slag is thoroughly removed after it has accumulated. Subsequently, a small amount of the melt is poured into a preheated steel ring mold, and the gas content is checked before the furnace by observing the solidification surface morphology to ensure the melt quality is up to standard. Finally, the melt temperature is adjusted to a pouring temperature of 700-720°C, and a preheated ladle is used to pour it smoothly and continuously into the metal mold cavity that has been preheated to 300-400°C and coated with paint. After it is completely solidified, the AlSi9Cu3 alloy casting is obtained.

[0046] The AlSi9Cu3 alloy castings are based on weight and include: 8.5-10% Si (silicon), less than or equal to 1% Fe (iron), 2.1-4.0% Cu (copper), less than or equal to 0.5% Mn (manganese), 0.2-0.55% Mg (magnesium), and less than or equal to 1.2% Zn (zinc).

[0047] The copper-plated graphene nanosheet slurry prepared through the above steps was filtered and freeze-dried to obtain powder. Using an analytical balance with an accuracy of 0.1 mg, powder equivalent to n wt% of graphene mass was weighed (e.g., to prepare 100g of aluminum-based composite material, if the addition amount is set to 1.0 wt%, then 1.0g of copper-plated graphene powder was weighed). The powder was placed in an aluminum foil package, and using a mechanical stirrer under high-purity nitrogen protection at a stirring speed of 200 rpm, the aluminum foil package was pressed into the AlSi9Cu3 alloy melt, and stirring was continued for 10 minutes to achieve uniform dispersion and good interfacial bonding of the copper-plated graphene nanosheets in the aluminum matrix. Finally, the mixed melt was poured into a preheated metal mold to obtain a composite material ingot.

[0048] Comparative Examples 1-10

[0049] For the comparative example, AlSi9Cu3 alloy was selected as the raw material and processed using the methods described above for preparing aluminum-based materials. The AlSi9Cu3 alloy melt was poured into a casting mold, the mold dimensions of which were specified in GBT1173-2013. After natural cooling, standard rod-shaped specimens were obtained. The mechanical properties of the specimens were tested using a universal tensile testing machine, and the testing standards were performed according to GBT228.1-2021.

[0050] Examples 1-10

[0051] In this embodiment, the same batch of AlSi9Cu3 alloy as the comparative example was used as the raw material. The aluminum-based material was prepared using the above-mentioned method. The graphene nanosheets after chemical copper plating were wrapped in aluminum foil and stirred and dispersed into the melt.

[0052] In Examples 1-10, 0.1-1.0 wt% of graphene nanosheets modified by chemical copper plating were added respectively. Subsequent dispersion treatment was completed according to the above steps.

[0053] The AlSi9Cu3 alloy melt was then poured into a casting mold, the mold dimensions of which were specified in GBT1173-2013. After natural cooling, standard rod-shaped specimens were obtained. The mechanical properties of the specimens were tested using a universal tensile testing machine, and the testing standards were in accordance with GBT 228.1-2021.

[0054] Table 1. Tensile test results of comparative specimens

[0055]

[0056] Table 2. Tensile test results of specimens from the examples.

[0057]

[0058] The performance comparison between Table 1 and Table 2 shows that the graphene nanosheets with added chemical copper plating manufactured by this invention can effectively improve the tensile strength and elongation (mechanical properties) of the test bar, and have a significant effect on improving the performance of aluminum alloy materials.

Claims

1. A graphene nanosheet composite aluminum-based material, characterized in that, include: Copper-plated graphene nanosheets are added to an aluminum-based melt, wherein the proportion of copper-plated graphene nanosheets added is 0.1%-1.0%. The copper-plated graphene nanosheets are graphene nanosheets with a copper atom plating layer formed on the surface of the graphene nanosheets.

2. The graphene nanosheet composite aluminum-based material as described in claim 1, characterized in that, The aluminum-based melt is obtained by melting an AlSi9Cu3 alloy.

3. The graphene nanosheet composite aluminum-based material as described in claim 1, characterized in that, The AlSi9Cu3 alloy specifically contains: 8.5-10% by weight of Si; Fe less than or equal to 1 weight percentage; 2.1-4.0% Cu by weight; Mn less than or equal to 0.5% by weight; 0.2-0.55% by weight of Mg; Less than or equal to 1.2% by weight of Zn, with the remainder being Al.

4. The graphene nanosheet composite aluminum-based material as described in claim 1, characterized in that, The copper-plated graphene nanosheets were prepared using the following method: Graphene nanosheets were added to a solution containing hexadecyltrimethylammonium chloride (CTAB) and copper sulfate, and stirred to uniformly disperse the graphene nanosheets. An aqueous solution of reducing agent is added dropwise to the dispersion system, causing copper ions to be reduced and deposited on the surface of graphene nanosheets, forming a copper atom coating.

5. The graphene nanosheet composite aluminum-based material as described in claim 4, characterized in that, The reducing agent is sodium borohydride, and the concentration of the sodium borohydride aqueous solution is 0.1-0.15 mol / L.

6. The graphene nanosheet composite aluminum-based material as described in claim 4, characterized in that, The dropping rate of the aqueous solution of the reducing agent is 1-2 mL / min.

7. The graphene nanosheet composite aluminum-based material as described in claim 4, characterized in that, The concentration of hexadecyltrimethylammonium chloride (CTAB) in the solution of hexadecyltrimethylammonium chloride (CTAB) is 0.1-0.5 mol / L, and the concentration of copper sulfate is 0.05-0.1 mol / L.

8. A method for preparing a graphene nanosheet composite aluminum-based material according to any one of claims 1-7, characterized in that, Includes the following steps: Graphene nanosheets were added to a solution containing hexadecyltrimethylammonium chloride (CTAB) and copper sulfate, and stirred to uniformly disperse the graphene nanosheets. An aqueous solution of reducing agent is added dropwise to the dispersion system, causing copper ions to be reduced and deposited on the surface of graphene nanosheets, forming a copper atom coating. Copper-plated graphene nanosheets are added to an aluminum-based melt, wherein the proportion of copper-plated graphene nanosheets added is 0.1%-1.0%.

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