Graphene modified aluminum-based composite plate and preparation method thereof

Abstract

The application discloses a graphene modified aluminum-based composite plate and a preparation method thereof, which comprises the following components in terms of mass ratio: aluminum alloy: ceramic: alkyl magnesium solution: graphene = 4500-5000: 10-50: 1000: 1; the ceramic particle size is 0.05-50 mu m; the aluminum alloy particle size is 10-100 mu m; the composite plate provided by the application has a tensile strength of up to 512 MPa, a yield strength of up to 407 MPa, and a corrosion rate of only 0.9 g / m 2 d, and the preparation method is simple and efficient.

Description

Technical Field

[0001] This invention relates to an aluminum-based composite material, and more specifically to a graphene-modified aluminum-based composite material and its preparation method. Background Technology

[0002] Power connection fittings are widely used metal accessories in the power transmission field. Because they are exposed to the atmosphere for extended periods, the materials used to manufacture these fittings must possess excellent corrosion resistance to ensure the long-term normal operation of transmission lines. Therefore, the selection of fitting materials is crucial for the safety and reliability of power transmission line operation. Currently, connection fittings are mainly manufactured using steel materials such as carbon structural steel, alloy structural steel, and malleable cast iron. However, with the development of ultra-high voltage power transmission projects, increasingly complex environmental conditions place higher demands on the lightweight, wear-resistant, and corrosion-resistant properties of overhead transmission line components, especially connection fittings. Existing steel materials can no longer meet these requirements.

[0003] Aluminum alloys possess low density, high thermal conductivity, high specific strength, and good plastic deformation capacity; however, due to limitations in their intrinsic properties, they exhibit many limitations in macroscopic performance. Aluminum-based composites formed by introducing a series of particulate reinforcements can retain the advantages of lightweight while exhibiting excellent physical and mechanical properties, such as better modulus, strength, and thermal stability, thus finding wide application in aerospace, transportation, and electronic packaging. Ceramic particles possess advantages such as high modulus, high hardness, low coefficient of thermal expansion, and corrosion resistance; aluminum-based composites using ceramic particles as the reinforcing phase combine the advantages of both. Graphene is a material with ultra-high elastic modulus, good thermal conductivity, and high electron mobility. By combining graphene with traditional materials, the performance of traditional materials can be effectively improved, thus becoming a research hotspot in recent years. For applications with complex operating environments and high requirements for hardware performance, the development of graphene-modified silicon carbide-reinforced aluminum-based composites has significant application value.

[0004] Chinese patent application number CN201611201840.X discloses a graphene-reinforced aluminum-based silicon carbide composite material and its preparation method. The method utilizes graphene ethanol dispersion atomization spraying technology to coat graphene on the surface of silicon carbide and aluminum powder, and then uses hot isostatic pressing technology to form the composite material. However, this technology is prone to leaving adsorbates on the surface, which has a significant adverse effect on the interfacial bonding strength. Furthermore, the hot isostatic pressing technology has low processing efficiency, and when combined with forging and other processing and strengthening methods in the later stage, it is easy to produce obvious defects such as cracks, which makes it difficult to improve the macroscopic mechanical properties of the material. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention discloses a graphene-modified aluminum-based composite material with excellent mechanical properties and its preparation method. This invention is achieved using the following technical solution:

[0006] A graphene-modified aluminum-based composite sheet comprises the following components in the indicated mass ratios:

[0007] Aluminum alloy: ceramic: alkyl magnesium solution: graphene = 4500-5000: 10-50: 1000: 1;

[0008] The ceramic particle size is 0.05–50 μm; the aluminum alloy particle size is 10–100 μm.

[0009] Furthermore, the ceramic includes SiC, B4C, TiC, or TiB2.

[0010] The preparation method of the graphene-modified aluminum-based composite material according to any one of the above includes the following steps:

[0011] (1) Clean the ceramic particles;

[0012] (2) Preparation of alkyl magnesium-graphene dispersion;

[0013] (3) Mix the products obtained in steps (1) and (2) with aluminum alloy powder;

[0014] (4) The graphene-modified aluminum-based composite plate is obtained by thermoforming the mixed powder obtained in step (3).

[0015] Furthermore, the cleaning in step (1) includes: ultrasonically cleaning the ceramic particles with deionized water at least four times at a power of 10-30kW, each time for 10 minutes, and then drying them.

[0016] Furthermore, step (2) includes: stirring the alkyl magnesium and graphene mixture at 30-50°C for 30-50 minutes in a protective atmosphere.

[0017] Furthermore, step (3) includes:

[0018] a) Mix the alkyl magnesium-graphene dispersion and ceramic particles in alcohol;

[0019] b) Filter and dry the mixture obtained in step a);

[0020] c) Mix aluminum alloy powder with the dried powder.

[0021] Furthermore, the mixing in step a) includes mixing at 15–35 r / min for 0.5–3 h.

[0022] Furthermore, the mixing in step c) includes mixing at 10–15 r / min for 5–8 h.

[0023] Furthermore, the thermoforming in step 4) includes: loading the mixed powder into a hot press mold, followed by vacuum hot pressing and forging.

[0024] Compared with the closest existing technology, the technical solution provided by the present invention has the following superior effects:

[0025] 1) The technical solution provided by this invention improves the interfacial bonding strength between the reinforcement and the matrix by improving the surface state of the reinforcement raw material. Ultrasonic cleaning of ceramic particles effectively removes adsorbates remaining on the surface of the ceramic particles during the preparation process, ensuring the smoothness and integrity of the particle surface. By coating the particles with graphene coated with a magnesium layer, a good metallurgical bonding interface is formed between the ceramic particles, graphene, and aluminum matrix using metallic magnesium. By premixing the two reinforcements before mixing with aluminum powder, the agglomeration phenomenon during powder mixing is greatly reduced, improving the uniformity of the composite material. The resulting hot-pressed blank has excellent plastic deformation capacity and processing performance.

[0026] 2) The technical solution provided by this invention exhibits good formability and no obvious defects during subsequent extrusion and forging processes, and its tensile strength is increased by 10% compared to composite materials reinforced with single ceramic particles; the resulting material has a tensile strength of not less than 460 MPa, a yield strength of not less than 385 MPa, a Brinell hardness of not less than 149 HBW, and a 48-hour salt spray corrosion test result of not exceeding 1.0 g / m³. 2 ·d, with a density of only 2.9 g / cm³ 3 The hardware samples prepared by this graphene-modified aluminum-based composite material not only have excellent mechanical properties, but also meet the requirements for corrosion resistance and wear resistance without special surface treatment processes. Detailed Implementation

[0027] To better understand this invention, the following further explanation of its contents is provided.

[0028] Example 1

[0029] (1) Mix silicon carbide particles with deionized water, and perform ultrasonic cleaning in four batches at an ultrasonic power of 10kW, each batch lasting 10 minutes. The cleaning medium used is deionized water. During the ultrasonic cleaning process, the mixture is mechanically stirred. Dry the cleaned silicon carbide particles.

[0030] (2) Under hydrogen protection, the alkyl magnesium solution and graphene mixture were stirred at 40°C for 30 min. The resulting liquid was the alkyl magnesium-graphene dispersion.

[0031] (3) The alkyl magnesium-graphene dispersion and silicon carbide were wet-mixed in an alcohol medium for 1 hour at a stirring rate of 20 r / min. Then, the mixture was filtered and dried, and then added to a V-type mixer along with 2024 aluminum alloy powder for dry mixing for 5 hours at a stirring rate of 15 r / min.

[0032] (4) The mixed powder is loaded into a hot press mold and vacuum hot press is performed. The hot-pressed billet is machined to obtain an ingot; the ingot is forged to obtain a plate for preparing connecting hardware.

[0033] Example 2

[0034] (1) Mix B4C particles with deionized water, and perform ultrasonic cleaning in four batches at an ultrasonic power of 20kW, each batch lasting 10 minutes. The cleaning medium used is deionized water. During the ultrasonic cleaning process, the mixture is mechanically stirred. Dry the cleaned silicon carbide particles.

[0035] (2) Under hydrogen protection, the alkyl magnesium solution and graphene mixture were stirred at 50°C for 40 min. The resulting liquid was the alkyl magnesium-graphene dispersion.

[0036] (3) The alkyl magnesium-graphene dispersion and silicon carbide were wet-mixed in an alcohol medium for 3 hours at a stirring rate of 35 r / min. Then, the mixture was filtered and dried, and then added to a V-type mixer along with 2024 aluminum alloy powder for dry mixing for 6 hours at a stirring rate of 12 r / min.

[0037] (4) The mixed powder is loaded into a hot press mold and vacuum hot press is performed. The hot-pressed billet is machined to obtain an ingot; the ingot is forged to obtain a plate for preparing connecting hardware.

[0038] Example 3

[0039] (1) Mix TiC particles with deionized water, and perform ultrasonic cleaning in four batches at an ultrasonic power of 30kW, each batch lasting 10 minutes. The cleaning medium used is deionized water. During the ultrasonic cleaning process, the mixture is mechanically stirred. Dry the cleaned silicon carbide particles.

[0040] (2) Under hydrogen protection, the alkyl magnesium solution and graphene mixture were stirred at 30°C for 50 min. The resulting liquid was the alkyl magnesium-graphene dispersion.

[0041] (3) The alkyl magnesium-graphene dispersion and silicon carbide were wet-mixed in an alcohol medium for 0.5 h at a stirring rate of 15 r / min. Then, the mixture was filtered and dried, and then added to a V-type mixer along with 6061 aluminum alloy powder for dry mixing for 8 h at a stirring rate of 10 r / min.

[0042] (4) The mixed powder is loaded into a hot press mold and vacuum hot press is performed. The hot-pressed billet is machined to obtain an ingot; the ingot is forged to obtain a plate for preparing connecting hardware.

[0043] Example 4

[0044] Except for the use of TiB2 ceramic particles, the other steps are the same as in Example 3.

[0045] The mass ratios of each component in Examples 1-4 are shown in Table 1, and the performance parameters of the graphene-modified aluminum-based composite plates prepared therefrom are shown in Table 2.

[0046] Table 1. Mass ratio of each component in Examples 1-3

[0047] Example aluminum alloy ceramics Alkyl magnesium solution graphene 1 4500 25 1000 1 2 4700 10 1000 1 3 4860 28 1000 1 4 5000 50 1000 1

[0048] The ceramic particle size ranges from 0.05 to 50 μm, while the aluminum alloy particle size ranges from 10 to 100 μm.

[0049] Table 2. Performance parameters of the products prepared in Examples 1-3

[0050]

[0051]

[0052] As shown in Table 1, the tensile strength of this invention reaches 512 MPa, the yield strength reaches 407 MPa, and the corrosion rate is only 0.9 g / m. 2 •d, with excellent mechanical properties and corrosion resistance.

[0053] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of the claims of the present invention pending approval.

Claims

1. A method for preparing a graphene-modified aluminum-based composite sheet material, characterized by, The method comprises the following steps: (1) washing ceramic particles; (2) preparing an alkyl magnesium-graphene dispersion solution; (3) mixing the product obtained in step (1) (2) with aluminum alloy powder; (4) hot forming the mixed powder obtained in step (3) to obtain the graphene modified aluminum-based composite board; wherein the raw materials for preparing the graphene modified aluminum-based composite board comprise the following components in terms of mass ratio: aluminum alloy: ceramic: alkyl magnesium solution: graphene = 4500-5000: 10-50: 1000: 1; the particle size of the ceramic is 0.05-50 μm; the particle size of the aluminum alloy is 10-100 μm.

2. The method of claim 1, wherein the graphene-modified aluminum-based composite sheet is prepared by the steps of: preparing a graphene dispersion solution by dispersing graphene in a solvent; preparing a graphene-modified aluminum-based composite sheet by mixing the graphene dispersion solution with an aluminum-based composite sheet; and drying the graphene-modified aluminum-based composite sheet. The ceramic comprises SiC, B4C, TiC or TiB2.

3. The method of claim 1, wherein the graphene-modified aluminum-based composite sheet is prepared by the steps of: preparing a graphene dispersion solution by dispersing graphene in a solvent; preparing a graphene-modified aluminum-based composite sheet by mixing the graphene dispersion solution with an aluminum-based composite sheet; and drying the graphene-modified aluminum-based composite sheet. The washing in step (1) comprises: ultrasonic washing the ceramic particles with deionized water at a power of 10-30 kW for at least four times, 10 minutes each time, and then drying.

4. The method of claim 1, wherein the graphene-modified aluminum-based composite sheet is prepared by the steps of: preparing a graphene dispersion solution by dispersing graphene in a solvent; preparing an aluminum-based composite sheet by mixing an aluminum-based material with a dispersant; and mixing the graphene dispersion solution with the aluminum-based composite sheet. The step (2) comprises: stirring the mixed solution of alkyl magnesium and graphene in a protective atmosphere at 30-50 ℃ for 30-50 min.

5. The method of claim 1, wherein the graphene-modified aluminum-based composite sheet is prepared by the steps of: preparing a graphene dispersion solution by dispersing graphene in a solvent; preparing an aluminum-based composite sheet by mixing an aluminum-based material with a dispersant; and mixing the graphene dispersion solution with the aluminum-based composite sheet. The step (3) comprises: a) mixing the alkyl magnesium-graphene dispersion solution and ceramic particles in alcohol; b) filtering and drying the mixed solution obtained in step a); c) mixing aluminum alloy powder with the dried powder.

6. The method of claim 5, wherein the graphene-modified aluminum-based composite sheet is prepared by the steps of: preparing a graphene dispersion solution by dispersing graphene in a solvent; preparing a graphene-modified aluminum-based composite sheet by mixing the graphene dispersion solution with an aluminum-based composite sheet; and drying the graphene-modified aluminum-based composite sheet. The mixing in step a) comprises: mixing at 15-35 r / min for 0.5-3 h.

7. The method of claim 5, wherein the graphene-modified aluminum-based composite sheet is prepared by the steps of: preparing a graphene dispersion solution by dispersing graphene in a solvent; preparing an aluminum-based composite sheet by mixing an aluminum-based material with a dispersant; and mixing the graphene dispersion solution with the aluminum-based composite sheet. The mixing in step c) comprises: mixing at 10-15 r / min for 5-8 h.

8. The method of claim 1, wherein the graphene-modified aluminum-based composite sheet is prepared by the steps of: preparing a graphene dispersion solution by dispersing graphene in a solvent; preparing an aluminum-based composite sheet by mixing an aluminum-based material with a dispersant; and mixing the graphene dispersion solution with the aluminum-based composite sheet. The hot forming in step 4) comprises: loading the mixed powder into a hot pressing mold, and then vacuum hot pressing and forging.

9. A graphene-modified aluminum-based composite sheet material, characterized by, The graphene modified aluminum-based composite board is prepared by the method of any one of claims 1-8.

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