Electrical graphene-aluminum alloy rod and method of making same

Abstract

This application relates to the field of electrical materials technology, specifically disclosing an electrical graphene aluminum alloy rod and its preparation method; an electrical graphene aluminum alloy rod comprises the following raw materials in the following weight ratio: magnesium 0.3-0.5%, graphene 0.05-0.08%, silicon 1-3%, zinc 0.3-0.6%, tin 0.01-0.03%, chromium 0.005-0.008%, lanthanum 0.2-0.5%, boron 0.4-0.8%, toughening agent 1-3%, binder 0.5-0.8%, and the balance being aluminum; under the synergistic effect of each component, the overall strength of the aluminum alloy material can be effectively improved, while maintaining the good conductivity of the aluminum alloy material.

Description

A graphene-aluminum alloy rod for electrical applications and its preparation method Technical Field

[0001] This application relates to the field of electrical materials technology, and in particular to an electrical graphene aluminum alloy rod and its preparation method. Background Technology

[0002] In fields such as power transmission, new energy equipment, and aerospace, the performance of conductive materials directly determines energy transmission efficiency and equipment reliability. Currently, aluminum alloy conductors for electrical applications are widely used due to their lightweight, low cost, and excellent conductivity.

[0003] Traditional aluminum alloys are reinforced by adding elements such as magnesium, silicon, and iron. However, excessive addition can significantly reduce conductivity. Furthermore, iron and silicon in the alloy easily form brittle intermetallic compounds, leading to decreased ductility and increased susceptibility to cracking under bending or vibration conditions. The strength improvement of high-strength aluminum alloys typically comes at the cost of reduced conductivity, making it difficult to meet the dual requirements of high strength and high conductivity for high-voltage transmission lines. Summary of the Invention

[0004] To improve the strength and conductivity of traditional aluminum alloy rods, this application provides an electrical graphene aluminum alloy rod and its preparation method.

[0005] In a first aspect, this application provides an electrical graphene aluminum alloy rod, which adopts the following technical solution:

[0006] An electrical graphene-aluminum alloy rod comprises the following raw materials in the following weight ratios: magnesium 0.3-0.5%, graphene 0.05-0.08%, silicon 1-3%, zinc 0.3-0.6%, tin 0.01-0.03%, chromium 0.005-0.008%, lanthanum 0.2-0.5%, boron 0.4-0.8%, toughening agent 1-3%, binder 0.5-0.8%, and the balance being aluminum.

[0007] By adopting the above technical solutions, adding an appropriate amount of graphene to aluminum alloy materials can simultaneously improve strength and conductivity. Silicon and magnesium can form precipitated strengthening phases, effectively improving the strength of aluminum alloys; chromium and magnesium can improve the yield strength and tensile strength of aluminum alloys; boron, lanthanum, chromium, and tin can refine grains and inhibit high-temperature grain boundary embrittlement; boron can reduce the resistivity of aluminum alloys, improving strength while maintaining good conductivity; and lanthanum can also improve the dispersion effect of graphene in the aluminum alloy system.

[0008] Preferably, the adhesive is stearic acid.

[0009] By employing the above technical solution, stearic acid can modify the interfacial bonding effect between graphene and aluminum, enhance the shear strength of the graphene-aluminum interface, and thus improve the overall strength of the alloy. Utilizing the steric hindrance effect of its long-chain alkyl groups, it prevents graphene aggregation, improves the uniform dispersion of graphene in the aluminum matrix, and simultaneously preserves the complete conductive pathways of the graphene structure, thereby enhancing the alloy's strength while maintaining good conductivity.

[0010] Preferably, the toughening agent is carbon nanotubes.

[0011] By employing the above-mentioned technical solutions, carbon nanotubes possess good strength and stiffness. When added to an aluminum matrix, their high specific surface area and fibrous structure enable a toughening effect, improving the strength and toughness of the aluminum alloy. The distribution of carbon nanotubes within the alloy system can refine grain size and strengthen grain boundaries, eliminating alloy defects. When the aluminum alloy fractures, the carbon nanotubes can disperse the stress energy, penetrating into the alloy above and below the crack, thereby reducing the occurrence of fracture and crack formation, hindering crack propagation, and improving the overall elongation at break and toughness of the aluminum alloy.

[0012] Preferably, the carbon nanotubes have a diameter of 10-30 nm and a length of 5-8 μm.

[0013] By adopting the above technical solutions, controlling the size of carbon nanotubes within a reasonable range can enable carbon nanotubes to play a bridging role and improve the strength and fracture toughness of alloy materials.

[0014] Preferably, the surface of the carbon nanotubes is coated with nickel, and the raw materials of the plating solution include trisodium citrate, sodium dihydrogen phosphate, nickel sulfate, and ammonium chloride, wherein the mass ratio of trisodium citrate, sodium dihydrogen phosphate, nickel sulfate, and ammonium chloride is (40-50):(15-25):30:(20-30).

[0015] By employing the above-mentioned technical solution, nickel plating on the surface of carbon nanotubes can reduce the agglomeration of carbon nanotubes in the aluminum alloy matrix, promoting uniform dispersion of carbon nanotubes within the aluminum matrix and improving the overall strength and fracture toughness of the aluminum alloy material. Simultaneously, introducing nickel into the aluminum alloy system can increase the overall density of the alloy, thereby enhancing its overall compressive strength.

[0016] Preferably, the method for nickel plating the surface of carbon nanotubes includes the following specific steps:

[0017] Carbon nanotubes are first ultrasonically dispersed, and then the dispersed carbon nanotubes are mixed with a carbon nanotube dispersant to obtain pretreated carbon nanotubes. The pretreated carbon nanotubes are placed in a mixed acid and heated in a water bath, and then successively subjected to stannous chloride sensitization treatment and lead chloride activation treatment to obtain activated carbon nanotubes. The pH of the plating solution is adjusted to 8-9, and then the activated carbon nanotubes are electroless nickel plating, that is, a nickel layer is formed on the surface of the carbon nanotubes.

[0018] By employing the above-mentioned technical solutions, mixed acid purification treatment removes impurities from the surface of carbon nanotubes. The purified carbon nanotubes are finer and have a smoother, more even surface, improving their dispersibility. Combining ultrasonic dispersion of carbon nanotubes with surface nickel plating effectively enhances their dispersibility in the aluminum alloy matrix, while also increasing their surface activity and overall strength. Furthermore, nickel plating protects the carbon nanotube surface, preventing them from reacting with the matrix alloy and reducing the formation of carbides at high temperatures, thus preserving the electrical conductivity of the aluminum alloy.

[0019] Preferably, the carbon nanotube dispersant is hexadecyl dimethyl ammonium bromide, and the mass ratio of carbon nanotubes to carbon nanotube dispersant is 1:(0.2-0.4).

[0020] Preferably, the mixed acid is a mixture of nitric acid and sulfuric acid, wherein the volume ratio of nitric acid to sulfuric acid is 1:(2-3).

[0021] Secondly, this application provides a method for preparing an electrical graphene aluminum alloy rod, which adopts the following technical solution:

[0022] A method for preparing an electrical graphene aluminum alloy rod includes the following specific steps: mixing graphene and a binder evenly, then adding magnesium, silicon, zinc, tin, chromium, lanthanum, boron, toughening agent and aluminum and smelting to obtain a molten alloy liquid, degassing and refining the alloy liquid, and then casting, cooling and continuous rolling to obtain an electrical graphene aluminum alloy rod.

[0023] By adopting the above technical solution, the prepared aluminum alloy material can improve its strength while maintaining good electrical conductivity.

[0024] Preferably, the melting temperature is 690-760℃, the casting temperature is 680-700℃, and the temperature of the billet after cooling is 480-520℃.

[0025] In summary, this application has the following beneficial effects:

[0026] 1. This application utilizes graphene, which can simultaneously improve strength and conductivity, by adding appropriate amounts to aluminum alloy materials. It also employs silicon, magnesium, boron, lanthanum, chromium, and tin to enhance the yield strength and tensile strength of the aluminum alloy, refine grain size, and suppress high-temperature grain boundary embrittlement. Furthermore, it utilizes toughening agents and binders to improve the overall strength and fracture toughness of the aluminum alloy material.

[0027] 2. This application uses carbon nanotubes as a toughening agent, utilizing their high specific surface area and fibrous structure to achieve a toughening effect, reducing the occurrence of fractures and cracks in aluminum alloys, hindering crack propagation, and improving the strength and fracture toughness of aluminum alloys. Simultaneously, the surface of the carbon nanotubes is coated with nickel to reduce the agglomeration of carbon nanotubes in the aluminum alloy matrix. Introducing nickel into the aluminum alloy system increases the overall density of the alloy, thereby improving the overall compressive strength of the aluminum alloy. Detailed Implementation

[0028] The present application will be further described in detail below with reference to the embodiments.

[0029] All raw materials used in the examples are commercially available.

[0030] Example

[0031] Example 1

[0032] This embodiment provides an electrical graphene-aluminum alloy rod, comprising the following raw materials in the following weight ratios: magnesium 0.4%, graphene 0.07%, silicon 2%, zinc 0.5%, tin 0.02%, chromium 0.007%, lanthanum 0.4%, boron 0.6%, toughening agent 2%, binder 0.7%, and the balance being aluminum. The toughening agent is carbon nanotubes with an average diameter of 20 nm and a length of 7 μm, and the binder is stearic acid.

[0033] The preparation method of graphene aluminum alloy rod for electrical use includes the following specific steps: graphene and binder are mixed evenly, and then magnesium, silicon, zinc, tin, chromium, lanthanum, boron, toughening agent and aluminum are added and mixed. The mixture is melted at 730°C to obtain a molten alloy liquid. The alloy liquid is degassed and refined, and then cast at 690°C. Cooling is carried out during the casting process. The billet is cooled to 500°C and then continuously rolled to obtain the graphene aluminum alloy rod for electrical use.

[0034] Example 2

[0035] The difference between Example 2 and Example 1 is that the graphene aluminum alloy rod for electrical use includes the following raw materials in the following weight ratio: magnesium 0.3%, graphene 0.08%, silicon 1%, zinc 0.3%, tin 0.03%, chromium 0.005%, lanthanum 0.2%, boron 0.8%, toughening agent 1%, binder 0.8%, and the balance being aluminum.

[0036] Example 3

[0037] The difference between Example 3 and Example 1 is that the graphene aluminum alloy rod for electrical use includes the following raw materials in the following weight ratio: magnesium 0.5%, graphene 0.05%, silicon 3%, zinc 0.6%, tin 0.01%, chromium 0.008%, lanthanum 0.5%, boron 0.4%, toughening agent 3%, binder 0.5%, and the balance being aluminum.

[0038] Example 4

[0039] The difference between Example 4 and Example 1 is that the carbon nanotubes in the graphene aluminum alloy rod material for electrical use are coated with nickel. The plating solution materials include trisodium citrate, sodium dihydrogen phosphate, nickel sulfate, and ammonium chloride. The mass ratio of trisodium citrate, sodium dihydrogen phosphate, nickel sulfate, and ammonium chloride is 45:20:30:25.

[0040] The preparation method of graphene-aluminum alloy rods for electrical applications includes the following specific steps:

[0041] S1: Carbon nanotubes are ultrasonically dispersed for 2 hours beforehand, and then the dispersed carbon nanotubes are mixed with a carbon nanotube dispersant. The carbon nanotube dispersant is hexadecyl dimethyl ammonium bromide, and the mass ratio of carbon nanotubes to carbon nanotube dispersant is 1:0.3 to obtain pretreated carbon nanotubes.

[0042] The pretreated carbon nanotubes were placed in a mixed acid solution with a volume ratio of 2:1 to carbon nanotubes and heated in a water bath at 40°C for 4 hours. The mixed acid solution was a mixture of nitric acid and sulfuric acid with a volume ratio of 1:2.5. After removing the carbon nanotubes, they were then subjected to sensitization treatment in stannous chloride solution for 30 minutes and activation treatment in lead chloride solution with a volume ratio of 1:3:2 to carbon nanotubes, stannous chloride solution, and lead chloride solution. The mass fraction of stannous chloride in the stannous chloride solution was 0.02 g / mL, and the mass fraction of lead chloride in the lead chloride solution was 0.5 g / mL, thus obtaining activated carbon nanotubes.

[0043] Trisodium citrate, sodium dihydrogen phosphate, nickel sulfate, and ammonium chloride are mixed to form a plating solution. The pH of the plating solution is adjusted to 8.5 using ammonia water. Then, the activated carbon nanotubes are electrolessly plated with nickel. After drying, a nickel layer with an average thickness of 10 nm is formed on the surface of the carbon nanotubes.

[0044] S2: Graphene and carbon nanotubes are mixed evenly, and then magnesium, silicon, zinc, tin, chromium, lanthanum, boron, toughening agent and aluminum are added and mixed. The mixture is smelted at 730°C to obtain a molten alloy liquid. The alloy liquid is degassed and refined, and then cast at 690°C. During the casting process, the billet is cooled to 500°C and then continuously rolled to obtain a graphene aluminum alloy rod for electrical use.

[0045] Example 5

[0046] The difference between Example 5 and Example 4 is that the mass ratio of trisodium citrate, sodium dihydrogen phosphate, nickel sulfate, and ammonium chloride in the nickel plating process of carbon nanotubes is 40:25:30:20.

[0047] Example 6

[0048] The difference between Example 6 and Example 4 is that the mass ratio of trisodium citrate, sodium dihydrogen phosphate, nickel sulfate, and ammonium chloride in the nickel plating process of carbon nanotubes is 50:15:30:30.

[0049] Example 7

[0050] The difference between Example 7 and Example 4 is that the volume ratio of nitric acid and sulfuric acid in the carbon nanotube nickel plating process is 1:2.

[0051] Example 8

[0052] The difference between Example 8 and Example 4 is that the volume ratio of nitric acid and sulfuric acid in the carbon nanotube nickel plating process is 1:3.

[0053] Example 9

[0054] The difference between Example 9 and Example 4 is that carbon nanotube dispersant is not used in the carbon nanotube nickel plating process.

[0055] The preparation method of graphene-aluminum alloy rods for electrical applications includes the following specific steps:

[0056] S1: Carbon nanotubes were ultrasonically dispersed for 2 hours to obtain pretreated carbon nanotubes. The pretreated carbon nanotubes were placed in a mixed acid with a volume ratio of 2:1 to carbon nanotubes and heated in a water bath at 40°C for 4 hours. The mixed acid was a mixture of nitric acid and sulfuric acid with a volume ratio of 1:2.5. After removing the carbon nanotubes, they were sensitized in stannous chloride solution for 30 minutes and activated in lead chloride solution. The volume ratio of carbon nanotubes to stannous chloride solution and lead chloride solution was 1:3:2. The mass fraction of stannous chloride in the stannous chloride solution was 0.02 g / mL, and the mass fraction of lead chloride in the lead chloride solution was 0.5 g / mL, thus obtaining activated carbon nanotubes.

[0057] Trisodium citrate, sodium dihydrogen phosphate, nickel sulfate, and ammonium chloride are mixed to form a plating solution. The pH of the plating solution is adjusted to 8.5 using ammonia water. Then, the activated carbon nanotubes are electrolessly plated with nickel. After drying, a nickel layer with an average thickness of 10 nm is formed on the surface of the carbon nanotubes.

[0058] S2: Graphene and carbon nanotubes are mixed evenly, and then magnesium, silicon, zinc, tin, chromium, lanthanum, boron, toughening agent and aluminum are added and mixed. The mixture is smelted at 730°C to obtain a molten alloy liquid. The alloy liquid is degassed and refined, and then cast at 690°C. During the casting process, the billet is cooled to 500°C and then continuously rolled to obtain a graphene aluminum alloy rod for electrical use.

[0059] Example 10

[0060] The difference between Example 10 and Example 4 is that carbon nanotube dispersant and ultrasonic dispersion are not used in the carbon nanotube nickel plating process.

[0061] The preparation method of graphene-aluminum alloy rods for electrical applications includes the following specific steps:

[0062] S1: Carbon nanotubes were placed in a mixed acid, with a volume ratio of 2:1 between the mixed acid and carbon nanotubes. The mixture was heated in a water bath at 40°C for 4 hours. The mixed acid was a mixture of nitric acid and sulfuric acid, with a volume ratio of 1:2.5 between the nitric acid and sulfuric acid. After removing the carbon nanotubes, they were sensitized in a stannous chloride solution for 30 minutes and then activated in a lead chloride solution. The volume ratio of carbon nanotubes to the stannous chloride solution and the lead chloride solution was 1:3:2. The mass fraction of stannous chloride in the stannous chloride solution was 0.02 g / mL, and the mass fraction of lead chloride in the lead chloride solution was 0.5 g / mL. Activated carbon nanotubes were obtained.

[0063] Trisodium citrate, sodium dihydrogen phosphate, nickel sulfate, and ammonium chloride are mixed to form a plating solution. The pH of the plating solution is adjusted to 8.5 using ammonia water. Then, the activated carbon nanotubes are electrolessly plated with nickel. After drying, a nickel layer with an average thickness of 10 nm is formed on the surface of the carbon nanotubes.

[0064] S2: Graphene and carbon nanotubes are mixed evenly, and then magnesium, silicon, zinc, tin, chromium, lanthanum, boron, toughening agent and aluminum are added and mixed. The mixture is smelted at 730°C to obtain a molten alloy liquid. The alloy liquid is degassed and refined, and then cast at 690°C. During the casting process, the billet is cooled to 500°C and then continuously rolled to obtain a graphene aluminum alloy rod for electrical use.

[0065] Comparative Example

[0066] Comparative Example 1

[0067] The difference between Comparative Example 1 and Example 1 is that no toughening agent is used in the raw material of the graphene aluminum alloy rod for electrical use.

[0068] Comparative Example 2

[0069] The difference between Comparative Example 2 and Example 1 is that no adhesive is used in the raw material of the electrical graphene aluminum alloy rod.

[0070] Performance testing

[0071] The following performance tests were conducted on the electrical graphene aluminum alloy rods provided in Examples 1-10 and Comparative Examples 1-2 of this application. The specific test results are shown in Table 1.

[0072] Detection methods

[0073] I. Tensile strength and elongation at break

[0074] The tensile strength and elongation at break of the electrical graphene aluminum alloy rod specimen prepared in this application were tested using an electronic universal testing machine at room temperature. The tensile loading rate was fixed at 2 mm / min, and the load and displacement data were recorded.

[0075] II. Conductivity

[0076] The conductivity of the graphene-aluminum alloy rod sample for electrical applications prepared in this application was measured using a TX-300 intelligent metallic conductor resistivity meter.

[0077] III. Hardness

[0078] The hardness of the electrical graphene aluminum alloy rod sample prepared in this application was measured using an HB-3000 Brinell hardness tester.

[0079] Table 1: Performance Test Results Data Table

[0080]

[0081]

[0082] The performance test results show that the graphene-aluminum alloy rod prepared in this application has good tensile strength, elongation at break, and electrical conductivity. As demonstrated in Examples 4-8, nickel plating on the surface of the toughening agent carbon nanotubes effectively improves the tensile strength, elongation at break, and hardness of the aluminum alloy material, while reducing the impact on the electrical conductivity of the alloy material.

[0083] As shown in Examples 9 and 10, the nickel plating process using carbon nanotubes in Example 9 did not use a carbon nanotube dispersant, and the nickel plating process using carbon nanotubes in Example 10 did not use a carbon nanotube dispersant or ultrasonic dispersion. Performance testing results show that both the strength and fracture toughness of the aluminum alloy were affected. This further illustrates that in nickel plating of carbon nanotubes, pretreatment of the carbon nanotubes can effectively activate their surface activity and promote their full dispersion, thereby enhancing the toughness and strength of the alloy material.

[0084] By comparing Comparative Examples 1-2 with Example 1, it can be seen that Comparative Example 1 does not use toughening agent, and Comparative Example 2 does not use adhesive. The performance test results show that the comprehensive performance of the aluminum alloy material is reduced. The tensile strength and elongation at break of the aluminum alloy material prepared in Comparative Example 1 are significantly reduced, which also seriously shortens the service life of the aluminum alloy material in actual use.

[0085] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. An electrical graphene-aluminum alloy rod, characterized in that, The raw materials include the following components in the following weight ratios: magnesium 0.3-0.5%, graphene 0.05-0.08%, silicon 1-3%, zinc 0.3-0.6%, tin 0.01-0.03%, chromium 0.005-0.008%, lanthanum 0.2-0.5%, boron 0.4-0.8%, toughening agent 1-3%, binder 0.5-0.8%, and the balance being aluminum; the binder is stearic acid, which can modify the interfacial bonding effect between graphene and aluminum; the toughening agent is carbon nanotubes.

2. The graphene-aluminum alloy rod for electrical applications according to claim 1, characterized in that, The carbon nanotubes have a diameter of 10-30 nm and a length of 5-8 μm.

3. The graphene-aluminum alloy rod for electrical applications according to claim 1, characterized in that, The surface of the carbon nanotubes is coated with nickel. The raw materials of the nickel plating solution include trisodium citrate, sodium dihydrogen phosphate, nickel sulfate, and ammonium chloride. The mass ratio of trisodium citrate, sodium dihydrogen phosphate, nickel sulfate, and ammonium chloride is (40-50):(15-25):30:(20-30).

4. The graphene-aluminum alloy rod for electrical applications according to claim 3, characterized in that, The method for nickel plating on the surface of carbon nanotubes includes the following specific steps: pre-dispersing carbon nanotubes ultrasonically, then mixing the dispersed carbon nanotubes with a carbon nanotube dispersant to obtain pretreated carbon nanotubes, placing the pretreated carbon nanotubes in a mixed acid water bath for heating, and then sequentially subjecting them to stannous chloride sensitization treatment and lead chloride activation treatment to obtain activated carbon nanotubes, adjusting the pH of the plating solution to 8-9, and then performing electroless nickel plating on the activated carbon nanotubes to form a nickel layer coating on the surface of the carbon nanotubes.

5. The graphene-aluminum alloy rod for electrical applications according to claim 4, characterized in that, The carbon nanotube dispersant is hexadecyl dimethyl ammonium bromide, and the mass ratio of carbon nanotubes to carbon nanotube dispersant is 1:(0.2-0.4).

6. The graphene-aluminum alloy rod for electrical applications according to claim 4, characterized in that, The mixed acid is a mixture of nitric acid and sulfuric acid, wherein the volume ratio of nitric acid to sulfuric acid is 1:(2-3).

7. A method for preparing an electrical graphene aluminum alloy rod as described in any one of claims 1-6, characterized in that, The specific steps include: mixing graphene and binder evenly, then adding magnesium, silicon, zinc, tin, chromium, lanthanum, boron, toughening agent and aluminum to mix and melt, obtaining a molten alloy liquid, degassing and refining the alloy liquid, and then casting, cooling and continuous rolling to obtain an electrical graphene aluminum alloy rod.

8. The method for preparing the graphene-aluminum alloy rod for electrical applications according to claim 7, characterized in that, The melting temperature is 690-760℃, the casting temperature is 680-700℃, and the temperature of the billet after cooling is 480-520℃.

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