Copper graphene super copper wire and preparation method thereof

Abstract

The invention discloses a copper graphene super copper wire and a preparation method thereof, and belongs to the technical field of composite wire materials. The method comprises the following steps: firstly, growing graphene on the surfaces of pure copper, copper alloy and copper-based composite materials (pipes and wires) in situ to form a copper graphene composite conductor; the preparation method comprises the following steps: twisting copper-graphene composite wires, arranging the copper-graphene composite wires in a copper-graphene composite tube, welding and sealing the copper-graphene composite wires, sequentially performing drawing and heat treatment, repeating the steps of composite packaging and processing for n times, and finally performing annealing treatment to obtain the copper-graphene super copper wire with a layered reinforced structure. According to the composite wire, through the interface strengthening effect of graphene and three-dimensional conductive network construction, the conductivity is remarkably higher than that of pure copper, and the resistance stability under the high-temperature working condition is better than that of the pure copper. The product is suitable for aerospace wires, high-density integrated circuits, superconducting equipment and high-efficiency power transmission systems, has the advantages of high conductivity, low energy consumption and high-temperature stability, and can greatly improve the performance of electrical equipment and reduce energy loss.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite wire materials, and specifically relates to a copper-graphene super copper wire and a preparation method thereof, which is particularly suitable for electrical transmission scenarios with high conductivity and high-temperature stability. Background Art

[0002] In modern industry and electronics, conductors are key materials for transmitting electrical energy, and their performance plays a crucial role in the efficiency and stability of the entire system. Pure copper conductors are widely used in various electrical devices and circuits due to their excellent conductivity. However, with the continuous advancement of technology and the increasing complexity of application environments, the performance of pure copper conductors in high-temperature and high-intensity scenarios is limited. In high-temperature environments, the resistivity of pure copper increases significantly, resulting in increased energy loss and reduced transmission efficiency in copper conductors during high-temperature applications, making it difficult to meet the high-efficiency and stable transmission requirements of modern electronic devices. Furthermore, pure copper conductors have relatively limited mechanical strength and are prone to deformation or fracture when subjected to high mechanical stress, limiting their application in certain specialized applications, such as aerospace and high-end equipment manufacturing. To address the increased resistivity and insufficient mechanical strength of pure copper conductors at high temperatures, existing technologies attempt to enhance their performance by adding carbon nanomaterials (such as graphene and carbon nanotubes). Graphene, with its high electrical conductivity, excellent mechanical strength, and thermal stability, theoretically could significantly improve the performance of copper-based conductors. However, there are still challenges in practical applications: first, the bonding between graphene and the copper matrix is unstable, electron transmission is hindered, which limits the improvement of conductivity, and it is easy to separate during processing or use, affecting stability; second, traditional composite processes (such as powder metallurgy) are prone to introduce pore defects, destroying the density of the material, reducing conductivity and mechanical strength, increasing current resistance, leading to stress concentration and decreased thermal conductivity, and affecting high-temperature stability.

[0003] While existing technologies have made some progress in modifying copper-based conductors by adding carbon nanomaterials, they still face numerous deficiencies in terms of interfacial bonding strength, material density, directional reinforcement, and high-temperature stability. To address these issues, the present invention proposes a multi-stage composite encapsulation and drawing process, combined with in-situ graphene growth technology, to produce copper-graphene super-copper wires with a layered reinforced structure. This process aims to overcome the shortcomings of existing technologies and significantly improve the conductivity, mechanical strength, and high-temperature stability of copper-based conductors, meeting the demand for high-performance conductors in modern industry and electronics. Summary of the Invention

[0004] A method for preparing a copper-graphene super copper wire comprises the following steps:

[0005] Tube pretreatment and graphene growth: Copper tubes, copper alloy tubes, and copper-based composite tubes with lengths of 120-600 mm, outer diameters of 4-20 mm, and wall thicknesses of 0.5-2 mm were selected. The oxide layer was removed by mechanical polishing and pickling (5% HNO3 solution). Graphene was grown on the inner and outer surfaces of the copper tubes by CVD at 1000-1070°C in a methane atmosphere for 1 hour to form copper-graphene composite tubes.

[0006] Preparation and twisting of composite conductors: Graphene is grown on the surface of pure copper, copper alloy and copper / nanocarbon composite conductors (single diameter ≤ 0.5 mm) using the CVD method; multiple conductors are twisted into a wire bundle with a diameter of 3.0-18.0 mm, whose outer diameter is 0.1-0.5 mm smaller than the inner diameter of the copper-graphene composite tube.

[0007] Packaging and drawing: The wire bundle is placed into a copper-graphene composite tube, and the tube end is sealed by argon arc welding to form a composite rod; the composite rod is drawn in multiple passes (with a deformation rate of 5%-20% per pass) to produce a composite wire with a diameter of ≤0.5 mm.

[0008] Circular composite process: heat treat composite wires with a diameter of ≤0.5 mm at 200-1000°C for 0.5-4 h (vacuum or inert gas plus hydrogen protection), twist them after cooling; repeat the tubing, drawing and heat treatment steps n times to form a multi-layer graphene reinforced structure.

[0009] Annealing treatment: The final wire is annealed at 200-400 ℃ for 1-3 hours to eliminate residual stress and optimize the conductive network.

[0010] The copper-graphene composite wire prepared by the method of the present invention has a room temperature electrical conductivity 5%-20% higher than that of pure copper, a high temperature resistivity 10-20% lower than that of pure copper, a thermal conductivity 5-15% higher than that of pure copper, a tensile strength ≥200 MPa, an elongation 40-50%, and an ultimate current carrying capacity ≥1.0×10 5 A / cm 2 .

[0011] Beneficial effects:

[0012] Compared with existing technologies, the present invention has significant innovation and advantages. The present invention uses a graphene in-situ growth-tube-drawing process to significantly increase the graphene content and uniform dispersion within the composite conductor through repeated processing, thereby comprehensively optimizing the overall performance of the composite conductor, especially in high-temperature environments. This innovative technology not only increases the room temperature conductivity of the composite conductor by 5%-20% compared to pure copper, but also increases the conductivity by 5%-10% at 200°C, and the maximum current carrying capacity is as high as ≥1.0×10 5A / cm², meeting the stringent requirements of high-temperature electrical equipment, and also optimizing mechanical properties, maintaining a tensile strength of 200 MPa and an elongation of 40%-50%. The preparation method of the present invention is suitable for the large-scale production of new high-performance composite conductors, can facilitate technological breakthroughs in emerging fields, and has enormous commercial value. At the same time, the prepared composite conductors can significantly improve the performance of power electronic equipment and reduce energy consumption, which is in line with the major demands of national economic and social development for energy conservation, environmental protection, green development, and energy science and technology innovation. It has great practical significance and broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The drawings described herein are used to provide further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute improper limitations on the present application.

[0014] Figure 1 This is a process flow chart for preparing a high-performance composite wire according to an embodiment of the present invention;

[0015] Figure 2 Schematic diagram of the internal structure of a high-performance copper-graphene composite wire according to an embodiment of the present invention;

[0016] Figure 3 This is a photo of the high-performance copper-graphene composite wire of Example 4 of the present invention;

[0017] Figure 4 Performance characterization (I) of the high-performance copper-graphene composite wire in Example 4 of the present invention;

[0018] Figure 5 Performance characterization (II) of the high-performance copper-graphene composite wire in Example 4 of the present invention;

[0019] Figure 6 Performance characterization (III) of the high-performance copper-graphene composite wire in Example 4 of the present invention;

[0020] Figure 7 This is the performance characterization (IV) of the high-performance copper-graphene composite wire in Example 4 of the present invention. DETAILED DESCRIPTION

[0021] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The scope of protection of the present invention shall include all the contents of the claims. Through the following embodiments, those skilled in the art can realize all the contents of the claims of the present invention.

[0022] Example 1

[0023] Copper tube preparation: Take a copper tube with a length of 120 mm, an outer diameter of 4 mm, and a wall thickness of 0.5 mm, and polish and clean its surface and interior to remove impurities and oxide layers.

[0024] Graphene Growth: Graphene was grown on the surface and inside the tube using CVD. The growth temperature was 1000°C, the growth time was 1 hour, and the carbon source gas was methane.

[0025] Composite wire bundle preparation: Graphene was grown on the surface of 0.2 mm diameter high-purity copper wire (purity ≥ 99.99%) using CVD, using the same growth temperature and time as above. Multiple high-purity copper wires were twisted together to form a wire bundle.

[0026] Tubing and sealing: Figure 1 As shown, the above-mentioned composite wire bundle is loaded into a copper-graphene composite tube, the outer diameter of the wire bundle is 0.1 mm smaller than the inner diameter of the copper-graphene composite tube, and the two ends of the tube are sealed to form a copper-graphene composite rod.

[0027] Drawing process: The composite rod was drawn in multiple passes with a deformation rate of 15% per pass to produce a copper-graphene composite wire with a diameter of 0.2 mm.

[0028] Heat treatment and twisting: The composite wires were heat treated at 200°C for 0.5 h, then naturally cooled to room temperature under vacuum before being removed from the furnace. Twisted again, the tube-loading, sealing, drawing, and heat treatment steps were repeated four times.

[0029] Annealing treatment: The final composite wire is annealed to obtain copper / graphene super copper wire. Figure 2 As shown in the figure, the composite wire has a layered structure in which graphene uniformly covers the copper matrix. Figure 4 、 Figure 5 、 Figure 6 and Figure 7 As shown in the figure, the room temperature conductivity of the copper wire is 5% higher than that of pure copper, the high temperature resistivity is 5% lower than that of pure copper, the thermal conductivity is 5% higher than that of pure copper, the tensile strength is 200 MPa, the elongation is 40%, and the maximum current carrying capacity is 1.0×10 5 A / cm 2 .

[0030] Example 2

[0031] Preparation of copper alloy tube: Take a copper-tin alloy tube with a length of 300 mm, an outer diameter of 12 mm, and a wall thickness of 1 mm, and polish and clean it to remove impurities and oxide layer.

[0032] Graphene growth: Graphene was grown on the surface and inside the copper tube using the CVD method at a growth temperature of 1035 °C for 1 h, using methane as the carbon source gas.

[0033] Composite wire bundle preparation: Graphene was grown on the surface of 0.3 mm diameter in-situ graphene-reinforced copper composite wires using CVD. Multiple strands of these wires were twisted together to form a wire bundle.

[0034] Tubing and sealing: Figure 1 As shown, the composite wire bundle is loaded into the copper-graphene composite tube. The outer diameter of the wire bundle is 0.3 mm smaller than the inner diameter of the copper-graphene composite tube. The two ends of the tube are sealed to form a copper-graphene composite rod.

[0035] Drawing process: The composite rod was drawn in multiple passes with a deformation rate of 10% per pass to produce a copper-graphene composite wire with a diameter of 0.3 mm.

[0036] Heat Treatment and Twisting: Heat treat the composite wire at 300°C for 2 hours. Allow to cool naturally to room temperature under an inert atmosphere before removing from the furnace. Repeat the tubing, sealing, drawing, and heat treatment steps five times.

[0037] Annealing treatment: The final composite wire is annealed to obtain copper / graphene super copper wire. Figure 4 、 Figure 5 、 Figure 6 and Figure 7 As shown in the figure, the room temperature conductivity of the copper wire is 10% higher than that of pure copper, the high temperature resistivity is 5% lower than that of pure copper, the thermal conductivity is 10% higher than that of pure copper, the tensile strength is 220 MPa, the elongation is 42%, and the maximum current carrying capacity is 1.2×10 5 A / cm 2 .

[0038] Example 3

[0039] Copper tube preparation: Take a copper tube with a length of 600 mm, an outer diameter of 20 mm, and a wall thickness of 2 mm, and polish and clean it to remove impurities and oxide layers.

[0040] Graphene growth: Graphene was grown on the surface and inside the copper tube using CVD at a growth temperature of 1070 °C for 1 h, using methane as the carbon source gas.

[0041] Composite wire bundle preparation: Graphene was grown on the surface of 0.5 mm diameter copper powder using CVD-grown graphene followed by hot pressing and sintering. Graphene was then grown on the surface using CVD. Multiple strands of these wires were twisted together to form a wire bundle.

[0042] Tubing and sealing: Figure 1 As shown, the composite wire bundle is loaded into the copper-graphene composite tube. The outer diameter of the wire bundle is 0.5 mm smaller than the inner diameter of the copper-graphene composite tube. The two ends of the tube are sealed to form a copper-graphene composite rod.

[0043] Drawing process: The composite rod was drawn in multiple passes with a deformation rate of 20% per pass to produce a copper-graphene composite wire with a diameter of 0.5 mm.

[0044] Heat Treatment and Twisting: Heat the composite wires at 400°C for 4 hours, then cool them naturally to room temperature under vacuum before removing them from the furnace. Repeat the tubing, sealing, drawing, and heat treatment steps six times.

[0045] Annealing treatment: The final composite wire is annealed to obtain copper / graphene super copper wire. Figure 4 、 Figure 5 、 Figure 6 and Figure 7 As shown in the figure, the room temperature conductivity of the copper wire is 20% higher than that of pure copper, the high temperature resistivity is 10% lower than that of pure copper, the thermal conductivity is 15% higher than that of pure copper, the tensile strength is 250 MPa, the elongation is 50%, and the maximum current carrying capacity is 1.5×10 5 A / cm 2 .

[0046] Example 4

[0047] Copper tube preparation: Take a copper tube with a length of 200 mm, an outer diameter of 4 mm, and a wall thickness of 0.5 mm, polish and clean it to remove impurities and oxide layer.

[0048] Graphene growth: Graphene was grown on the surface and inside the copper tube using CVD at a temperature of 1020 °C for 1 h, using methane as the carbon source gas.

[0049] Composite wire bundle preparation: Graphene was grown on the surface of a 0.2 mm diameter copper / graphene composite wire produced by winding and drawing using CVD. Multiple strands of these wires were then twisted together to form a wire bundle.

[0050] Tubing and sealing: Figure 1 As shown, the composite wire bundle is loaded into the copper-graphene composite tube. The outer diameter of the wire bundle is 0.1 mm smaller than the inner diameter of the copper-graphene composite tube. The two ends of the tube are sealed to form a copper-graphene composite rod.

[0051] Drawing process: The composite rod was drawn in multiple passes with a deformation rate of 8% per pass to produce a copper-graphene composite wire with a diameter of 1 mm.

[0052] Heat Treatment and Twisting: The composite wires were heat treated at 300°C for 1.5 hours, then naturally cooled to room temperature under an inert atmosphere before being removed from the furnace. The tubing, sealing, drawing, and heat treatment steps were repeated six times, resulting in a composite wire with a final diameter of 0.2 mm.

[0053] Annealing treatment: The final composite wire is annealed to obtain copper / graphene super copper wire. Figure 3 As shown, the composite wire of Example 4 has a smooth surface and uniform diameter. Figure 4 、 Figure 5 、 Figure 6 and Figure 7 As shown in the figure, the room temperature conductivity of the copper wire is 2.3% higher than that of pure copper, the high temperature resistivity is 4.6% lower than that of pure copper, the thermal conductivity is 8% higher than that of pure copper, the tensile strength is 213 MPa, the elongation is 27%, and the maximum current carrying capacity is 1.24×10 5 A / cm 2 .

[0054] Example 5

[0055] Copper tube preparation: Take a copper tube with a length of 400 mm, an outer diameter of 16 mm, and a wall thickness of 1.5 mm, polish and clean it to remove impurities and oxide layer.

[0056] Graphene growth: Graphene was grown on the surface and inside the copper tube using CVD at a growth temperature of 1050 °C for 1 h, using methane as the carbon source gas.

[0057] Composite wire bundle preparation: Graphene was grown on the surface of 0.4 mm diameter copper / carbon nanotube composite wires, which were produced by winding and drawing. Multiple strands of these wires were twisted together to form a wire bundle.

[0058] Tubing and sealing: Figure 1 As shown, the composite wire bundle is loaded into the copper-graphene composite tube. The outer diameter of the wire bundle is 0.4 mm smaller than the inner diameter of the copper-graphene composite tube. The two ends of the tube are sealed to form a copper-graphene composite rod.

[0059] Drawing process: The composite rod was drawn in multiple passes with a deformation rate of 15% per pass to produce a copper-graphene composite wire with a diameter of 0.4 mm.

[0060] Heat Treatment and Twisting: Heat the composite wires at 350°C for 3 hours, then cool them naturally to room temperature under vacuum before removing them from the furnace. Repeat the tubing, sealing, drawing, and heat treatment steps eight times.

[0061] Annealing treatment: The final composite wire is annealed to obtain copper / graphene super copper wire. Figure 4 、 Figure 5 、 Figure 6 and Figure 7 As shown in the figure, the room temperature conductivity of the copper wire is 15% higher than that of pure copper, the high temperature resistivity is 8% lower than that of pure copper, the thermal conductivity is 12% higher than that of pure copper, the tensile strength is 230 MPa, the elongation is 48%, and the maximum current carrying capacity is 1.3×105 A / cm 2 .

[0062] Example 6

[0063] Copper tube preparation: Take a copper tube with a length of 250 mm, an outer diameter of 10 mm, and a wall thickness of 1 mm, and polish and clean it to remove impurities and oxide layers.

[0064] Graphene growth: Graphene was grown on the surface and inside the copper tube using CVD at a temperature of 1040 °C for 1 h, using methane as the carbon source gas.

[0065] Composite wire bundle preparation: Graphene was grown on the surface of a 0.2 mm diameter powder metallurgy copper / carbon nanotube composite wire using CVD. Multiple strands of these wires were twisted together to form a wire bundle.

[0066] Tubing and sealing: Figure 1 As shown, the composite wire bundle is loaded into the copper-graphene composite tube. The outer diameter of the wire bundle is 0.3 mm smaller than the inner diameter of the copper-graphene composite tube. The two ends of the tube are sealed to form a copper-graphene composite rod.

[0067] Drawing process: The composite rod was drawn in multiple passes with a deformation rate of 12% per pass to produce a copper-graphene composite wire with a diameter of 0.2 mm.

[0068] Heat Treatment and Twisting: Heat the composite wires at 320°C for 2.5 hours, then cool them naturally to room temperature under an inert atmosphere before removing them from the furnace. Repeat the tubing, sealing, drawing, and heat treatment steps nine times.

[0069] Annealing treatment: The final composite wire is annealed to obtain copper / graphene super copper wire. Figure 4 、 Figure 5 、 Figure 6 and Figure 7 As shown in the figure, the room temperature conductivity of the copper wire is 13% higher than that of pure copper, the high temperature resistivity is 7% lower than that of pure copper, the thermal conductivity is 9% higher than that of pure copper, the tensile strength is 225 MPa, the elongation is 46%, and the maximum current carrying capacity is 1.2×10 5 A / cm 2 .

[0070] Example 7

[0071] Copper tube preparation: Take a copper tube with a length of 500 mm, an outer diameter of 18 mm, and a wall thickness of 1.8 mm, and polish and clean it to remove impurities and oxide layers.

[0072] Graphene growth: Graphene was grown on the surface and inside the copper tube using CVD at a growth temperature of 1060 °C for 1 h, using methane as the carbon source gas.

[0073] Composite wire bundle preparation: Graphene is grown on the surface of 0.5 mm diameter high-purity copper wire (purity ≥99.99%) using CVD. Multiple strands of these wires are then twisted together to form a wire bundle.

[0074] Tubing and sealing: Figure 1 As shown, the composite wire bundle is loaded into the copper-graphene composite tube. The outer diameter of the wire bundle is 0.5 mm smaller than the inner diameter of the copper-graphene composite tube. The two ends of the tube are sealed to form a copper-graphene composite rod.

[0075] Drawing process: The composite rod was drawn in multiple passes with a deformation rate of 18% per pass to produce a copper-graphene composite wire with a diameter of 0.5 mm.

[0076] Heat Treatment and Twisting: Heat the composite wires at 380°C for 3.5 hours, then cool them naturally to room temperature under vacuum before removing them from the furnace. Repeat the tubing, sealing, drawing, and heat treatment steps 10 times.

[0077] Annealing treatment: The final composite wire is annealed to obtain copper / graphene super copper wire. Figure 4 、 Figure 5 、 Figure 6 and Figure 7 As shown in the figure, the room temperature conductivity of the copper wire is 18% higher than that of pure copper, the high temperature resistivity is 9% lower than that of pure copper, the thermal conductivity is 14% higher than that of pure copper, the tensile strength is 240 MPa, the elongation is 49%, and the maximum current carrying capacity is 1.4×10 5 A / cm 2 .

[0078] Example 8

[0079] Preparation of copper alloy tube: A copper-rhenium alloy tube with a length of 500 mm, an outer diameter of 18 mm, and a wall thickness of 1.8 mm was polished and cleaned to remove impurities and oxide layers.

[0080] Graphene growth: Graphene was grown on the surface and inside of a copper-rhenium alloy tube using CVD at a growth temperature of 1060°C for 1 h, using methane as the carbon source gas.

[0081] Composite wire bundle preparation: Graphene was grown on the surface of a 0.5 mm diameter copper-silver alloy wire using CVD. Multiple strands of these wires were then twisted together to form a wire bundle.

[0082] Tubing and sealing: Figure 1As shown, the composite wire bundle is loaded into the copper-graphene composite tube. The outer diameter of the wire bundle is 0.5 mm smaller than the inner diameter of the copper-graphene composite tube. The two ends of the tube are sealed to form a copper-graphene composite rod.

[0083] Drawing process: The composite rod was drawn in multiple passes with a deformation rate of 18% per pass to produce a copper-graphene composite wire with a diameter of 0.5 mm.

[0084] Heat Treatment and Twisting: Heat treat the composite wire at 200°C for 3.5 hours. Cool naturally to room temperature under vacuum before removing from the furnace. Repeat the tubing, sealing, drawing, and heat treatment steps twice.

[0085] Annealing: The final composite wire is annealed to produce a copper / graphene super copper wire. Tests show that the room temperature conductivity of this copper wire is 5% higher than that of pure copper, the high temperature resistivity is 3% lower than that of pure copper, and the thermal conductivity is 1% higher than that of pure copper. The tensile strength is 300 MPa, the elongation is 30%, and the maximum current carrying capacity is 1.4×10 5 A / cm 2 .

[0086] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

Claims

1. A method for preparing a copper-graphene super copper wire, characterized in that: The following steps are involved: 1) The surface and interior of pure copper, copper alloy, and copper-based composite tubes are polished and cleaned to remove impurities and oxide layers. Graphene is then uniformly grown on the surface and interior of the copper tubes using chemical vapor deposition (CVD) to form copper-graphene composite tubes. 2) Graphene is grown on the surface of pure copper, copper alloy, and copper / nanocarbon composite wires using the CVD method, and then multiple graphene-grown wires are twisted together to form a copper / graphene composite wire bundle; 3) placing the copper / graphene composite wire bundle prepared in step 2) into the copper / graphene composite tube prepared in step 1) so that the outer diameter of the composite wire bundle is 0.1-0.5 mm smaller than the inner diameter of the copper / graphene composite tube, and then sealing both ends of the composite tube to form a copper / graphene composite rod; 4) performing multiple drawing processes on the copper / graphene composite rod formed in step 3), controlling the deformation rate of each process, and producing a copper-graphene composite wire; 5) Repeat steps 1) to 4) in sequence to perform graphene growth, wire twisting, tube assembly, sealing, drawing and heat treatment, and the number of cycles is n times; 6) Annealing the final copper / graphene composite wire after the n-times cycle treatment to obtain a copper / graphene super copper wire.

2. The method for preparing a copper-graphene super copper wire according to claim 1, wherein: In step 1), the copper tube has the following dimensions: length 120-600 mm, outer diameter 4-20 mm, and wall thickness 0.5-2 mm.

3. The method for preparing a copper-graphene super copper wire according to claim 1, wherein: In step 1) and step 2), the process parameters of the CVD method are: growth temperature of 1000-1070° C., growth time of 1 h, and carbon source gas of methane.

4. The method for preparing a copper-graphene super copper wire according to claim 1, wherein: In step 2), pure copper, copper alloy and copper / nano-carbon composite material are selected from at least one of the following: ①High-purity copper (purity ≥99.99%); ② In-situ endogenous graphene reinforced copper composites; ③ Copper / graphene composite materials made by CVD growth of graphene on the surface of copper powder followed by hot pressing and sintering molding and plastic processing; ④ Copper / graphene composite material formed by winding and drawing; ⑤ Copper / carbon nanotube composite materials formed by winding and drawing; ⑥ Powder metallurgy copper / carbon nanotube composite materials; ⑦ Copper-tin alloy, copper-silver alloy, copper-tellurium alloy and copper alloy containing rare earth, etc.

5. The method for preparing a copper-graphene super copper wire according to claim 1, wherein: In step 2), the diameter of the copper and copper / nano-carbon composite wires is ≤0.5 mm, and the diameter of the wire bundle after twisting is in the range of 3.0-18.0 mm.

6. The method for preparing a copper-graphene super copper wire according to claim 1, wherein: In the step 4), the composite rod is subjected to multiple drawing processes with a deformation rate of 5%-20% per process.

7. The method for preparing a copper-graphene super copper wire according to claim 1, wherein: In step 5), the composite wire is heat treated at a temperature of 200-1000°C and held at this temperature for 0.5-4 hours. The heat treatment is carried out under vacuum or under inert gas and hydrogen protection conditions, and the composite wire is naturally cooled to room temperature before being taken out of the furnace.

8. The method for preparing a copper-graphene super copper wire according to claim 1, wherein: In the step 5), the number of cycles is n, where 4≤n≤10.

9. The method for preparing a copper-graphene super copper wire according to any one of claims 1 to 8, characterized in that: The obtained composite wire can meet the following requirements: The room temperature conductivity is 5%-20% higher than that of pure copper; High temperature resistivity is 5%-10% lower than pure copper; Thermal conductivity is 5-15% higher than pure copper; Tensile strength ≥200 MPa; Elongation 40-50%; Maximum current carrying capacity ≥1.0×10 5 A / cm 2 .

10. A copper-graphene super copper wire produced by the method according to any one of claims 1 to 9.

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