Preparation method of graphene copper wire

Abstract

The invention discloses a preparation method of a graphene copper wire. The method comprises the following steps: 1, pretreating graphene copper powder; secondly, the pretreated graphene copper powder is pressed and formed through hot isostatic pressing, and a rod-shaped blank is obtained; thirdly, the rod-shaped blank is drawn out and forged into a copper rod; and 4, processing the copper rod into a finished product graphene copper wire by adopting a wire drawing process. The graphene copper wire is prepared through graphene copper powder pretreatment, blank pressing, drawing forging and wire drawing, the defects that the technology is complex, graphene is not evenly dispersed, the interface bonding force is weak, brittle fracture is prone to occurring, cost is high, and efficiency is low are overcome, the product quality of the graphene copper wire is improved, and the yield of the graphene copper wire is increased; the high-power-density high-power-density high-power-density capacitor is suitable for the fields of new energy automobiles and overcharge technologies, high-power-density motors and industrial driving, high-frequency communication and signal transmission, power transmission and power grid equipment, aerospace and high-end electronic devices and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of preparation of metal composite materials, and particularly relates to a method for preparing graphene copper wire. Background Art

[0002] Copper wire is one of the commonly used materials in the power system and electronic devices. Its electrical conductivity, mechanical strength, high-temperature resistance, and long-term stability can no longer meet the current market application requirements. As a new type of composite material, graphene copper wire combines the high electrical conductivity and high strength of graphene with the ductility of copper, and shows significant application potential in the fields of new energy vehicles and ultra-fast charging technology, high-power density motors and industrial drives, high-frequency communication and signal transmission, power transmission and grid equipment, aerospace and high-end electronic devices, etc. Compared with copper wire, graphene copper wire has the technical advantages of ultra-high electrical and thermal conductivity, enhanced mechanical properties, lightweight, energy saving and consumption reduction, oxidation resistance and corrosion resistance. However, the current methods for preparing graphene copper composites have the disadvantages of complex processes, uneven dispersion of graphene, weak interfacial bonding force, easy brittle fracture, high cost, and low efficiency.

[0003] Therefore, a method for preparing graphene copper wire with simple process, reliable product quality and reduced cost is needed. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for preparing graphene copper wire in view of the above-mentioned deficiencies of the prior art. This method pre-treats graphene copper powder, performs hot isostatic pressing to form a blank, elongates and forges, and draws wires to prepare graphene copper wire, improving the product quality and yield of graphene copper wire, and solving the problems of complex existing processes, uneven dispersion of graphene, weak interfacial bonding force, easy brittle fracture, high cost, and low efficiency.

[0005] To solve the above technical problems, the technical solution adopted by the present invention is: a method for preparing graphene copper wire, characterized in that the method comprises the following steps: Step 1, pre-treatment: pre-treat graphene copper powder; Step 2, blank forming: use the blank forming method of hot isostatic pressing to press the pre-treated graphene copper powder in Step 1 into a shape to obtain a rod-shaped blank; Step 3, forging into a circle: elongate and forge the rod-shaped blank obtained in Step 2 into a copper rod; Step 4, wire drawing: use the wire drawing process to process the copper rod in Step 3 into a finished graphene copper wire.

[0006] The above preparation method of graphene copper wire is characterized in that the pretreatment process in step one is as follows: commercially available pre-coated graphene copper powder is vacuum-dried at 100 °C for 3 h, and then sieved to obtain powder with a particle size not exceeding 50 μm. Usually, the mass content of graphene in the commercially available pre-coated graphene copper powder is 1%.

[0007] The above preparation method of graphene copper wire is characterized in that the hot isostatic pressing process in step two is as follows: the pretreated graphene copper powder is loaded into a jacket, and a pressure of 160 MPa to 200 MPa is applied to the jacket and heated to 800 °C to 850 °C and held for 3 h to 4 h. Usually, in the present invention, hot isostatic pressing is carried out by introducing high-pressure argon gas into a container through a compressor to apply a pressure of 160 MPa to 200 MPa to the jacket, and at the same time heating to 800 °C to 850 °C through a heating furnace and holding for 3 h to 4 h, and then quickly cooling to 100 °C and taking out of the furnace. In the present invention, hot isostatic pressing is used to apply high temperature and high pressure to the pretreated graphene copper powder and press it into a rod-shaped blank. During the process of pressing and blanking, the initial powder porosity is relatively large, the forming pressure is small, and the powder particles mainly migrate and re-stack, and small particles fill the pores of small particles; in the middle stage, as the pressure gradually increases, the porosity decreases, the extrusion between powders intensifies, and local flow and fragmentation of powders occur; in the later stage, the pressure reaches the peak value, the powder is densified, and a rod-shaped blank is formed. The interaction of temperature and pressure causes tiny flow of graphene copper particles, basically eliminating the internal voids and cracks, and avoiding the oriented melting flow. Usually, the density of the obtained rod-shaped blank is 7.80 g / cm 3 or so.

[0008] The above preparation method of graphene copper wire is characterized in that in step three, the rod-shaped blank is heated to 800 °C to 850 °C, and then subjected to multi-pass drawing forging to process a copper rod with the maximum diameter size that can pass through the die of a copper wire drawing machine. The copper rod prepared by this process not only meets the maximum outer diameter size that can be bitten by the wire drawing machine, but also further improves its density and improves its mechanical properties. In the present invention, by controlling the forging temperature below the melting point of the graphene copper powder and performing multi-pass drawing forging, the graphene copper powder particles are diffusion-bonded to completely eliminate the voids and defects between the particles, forming a continuous and uniform microstructure, further densifying it, and improving the density and mechanical properties of the rod material. Usually, the density of the obtained copper rod is 8.50 g / cm 3 or so.

[0009] The above preparation method of graphene copper wire is characterized in that in step four, the copper rod is heated to 800 °C to 850 °C, and then subjected to multi-pass wire drawing to process the finished graphene copper wire. Usually, the density of the finished graphene copper wire is 8.92 g / cm 3 ~8.95 g / cm 3, close to the density of pure copper, 8.96 g / cm 3 , and its surface roughness meets Ra1.6.

[0010] The present invention has the following advantages compared with the prior art: 1. By pretreating graphene copper powder, isostatic hot pressing for billet forming, drawing forging, and wire drawing to prepare graphene copper wire, the present invention effectively avoids the disadvantages of complex process, uneven dispersion of graphene, weak interfacial bonding force, easy brittle fracture, high cost, and low efficiency, improves the product quality and yield rate of graphene copper wire, and is applicable to fields such as new energy vehicles and ultra-fast charging technology, high-power density motors and industrial drives, high-frequency communication and signal transmission, power transmission and grid equipment, aerospace and high-end electronic devices.

[0011] 2. The present invention directly uses ready-made graphene copper powder to prepare graphene copper wire, effectively simplifies the process and improves the performance of graphene copper wire, and the process is simple and reliable, greatly reducing the production cost, and is applicable to the industrial production of graphene copper wire with high conductivity, high thermal conductivity, and high strength.

[0012] 3. The graphene copper wire prepared by the present invention using the compound process of drawing forging + wire drawing has a high density, small surface roughness, high product quality, and its conductivity and mechanical properties can meet the usage requirements.

[0013] The technical solution of the present invention will be further described in detail below with reference to the drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a flow chart of the preparation method of the graphene copper wire of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0015] Example 1 As Figure 1 shown, this embodiment includes the following steps: Step 1. Pretreatment: Commercially available pre-coated graphene copper powder (graphene mass content is 1%) is vacuum-dried at 100 °C for 3 h, and then sieved to obtain powder with a particle size not exceeding 50 μm; Step 2. Billet forming: Using the isostatic hot pressing method for billet forming, the pretreated graphene copper powder in Step 1 is filled into a carbon steel jacket, high-pressure argon gas is introduced into the container through a compressor, a pressure of 160 MPa is applied to the carbon steel jacket, and at the same time, it is heated to 800 °C by a heating furnace and kept for 4 h, then slowly depressurized, and quickly cooled to 100 °C and taken out of the furnace to obtain a rod-shaped billet with a density of about 7.80 g / cm 3 ; Step 3. Forging into a circle: The rod-shaped billet obtained in Step 2 is heated to 800 °C, and then subjected to 20 passes of drawing forging to obtain a copper rod with an outer diameter of 31 mm; Step 4. Wire drawing: Heat the copper rod in Step 3 to 800 °C, and then perform wire drawing in 8 passes to obtain a finished graphene copper wire with a density of 8.93 g / cm 3 , a surface roughness meeting Ra 1.6, and a wire diameter of 1 mm.

[0016] Perform eddy current testing, conductivity testing, and mechanical property testing on the graphene copper wire prepared in this example in sequence, and perform eddy current flaw detection in accordance with the standard YS / T 585-2013 "Eddy Current Flaw Detection Method for Copper and Copper Alloy Bars and Wires". The test results meet the standard requirements. At the same time, the test results show that the conductivity of the graphene copper wire is 117.7% IACS (International Annealed Copper Standard), meeting the usage requirements, and the mechanical properties of the graphene copper wire meet the requirements of the standard GB / T 2040-2017 "Copper and Copper Alloy Wires".

[0017] Example 2 As Figure 1 shown, this example includes the following steps: Step 1. Pretreatment: Vacuum-dry commercially available pre-coated graphene copper powder (graphene mass content is 1%) at 100 °C for 3 h, and then screen it to obtain powder with a particle size not exceeding 50 μm; Step 2. Billet making: Adopt the billet making method of hot isostatic pressing. Load the pretreated graphene copper powder in Step 1 into a carbon steel jacket, introduce high-pressure argon gas into the container through a compressor, apply a pressure of 180 MPa to the carbon steel jacket, and at the same time heat it to 830 °C through a heating furnace and keep it for 3.5 h. Then slowly release the pressure and quickly cool it to 100 °C and take it out of the furnace to obtain a rod-shaped billet with a density of about 7.80 g / cm 3 ; Step 3. Forging into a circle: Heat the rod-shaped billet obtained in Step 2 to 830 °C, and then perform 19 passes of drawing forging to obtain a copper rod with an outer diameter of 33 mm; Step 4. Wire drawing: Heat the copper rod in Step 3 to 830 °C, and then perform wire drawing in 12 passes to obtain a finished graphene copper wire with a density of 8.92 g / cm 3 , a surface roughness meeting Ra 1.6, and a wire diameter of 0.8 mm.

[0018] Perform eddy current testing, conductivity testing, and mechanical property testing on the graphene copper wire prepared in this example in sequence, and perform eddy current flaw detection in accordance with the standard YS / T 585-2013 "Eddy Current Flaw Detection Method for Copper and Copper Alloy Bars and Wires". The test results meet the standard requirements. At the same time, the test results show that the conductivity of the graphene copper wire is 117.4% IACS (International Annealed Copper Standard), meeting the usage requirements, and the mechanical properties of the graphene copper wire meet the requirements of the standard GB / T 2040-2017 "Copper and Copper Alloy Wires".

[0019] Example 3 As Figure 1 shown, this embodiment includes the following steps: Step 1, pretreatment: The commercially available pre-coated graphene copper powder (with a graphene mass content of 1%) is vacuum-dried at 100 °C for 3 h, and then sieved to obtain a powder with a particle size not exceeding 50 μm; Step 2, billet making: Adopt the billet making method of hot isostatic pressing. Load the pretreated graphene copper powder in Step 1 into a carbon steel jacket. Pass high-pressure argon into the container through a compressor, apply a pressure of 200 MPa to the carbon steel jacket, and at the same time heat it to 850 °C through a heating furnace and hold for 3 h. Then slowly release the pressure and quickly cool it to 100 °C and take it out of the furnace to obtain a rod-shaped billet with a density of about 7.80 g / cm 3 ³; Step 3, circular forging: Heat the rod-shaped billet obtained in Step 2 to 850 °C, and then perform 22 passes of drawing forging to obtain a copper rod with an outer diameter of 29 mm; Step 4, wire drawing: Heat the copper rod in Step 3 to 850 °C, and then perform 16 passes of wire drawing to obtain a finished graphene copper wire with a density of 8.95 g / cm 3 ³, a surface roughness meeting Ra1.6, and a wire diameter of 0.5 mm.

[0020] The graphene copper wire prepared in this embodiment is successively subjected to eddy current detection, conductivity detection, and mechanical property testing, and eddy current flaw detection is carried out in accordance with the standard YS / T 585-2013 "Eddy Current Flaw Detection Method for Copper and Copper Alloy Rods and Wires". The detection results meet the standard requirements. At the same time, the detection results show that the conductivity of the graphene copper wire is 117.4% IACS (International Annealed Copper Standard), meeting the usage requirements, and the mechanical properties of the graphene copper wire meet the requirements of the standard GB / T 2040-2017 "Copper and Copper Alloy Wires".

[0021] The above is only a preferred embodiment of the present invention and does not impose any limitation on the present invention. Any simple modification, change, and equivalent change made to the above embodiments according to the technical essence of the invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A method for preparing graphene copper wire, characterized in that, The method comprises the following steps: Step 1, pretreatment: performing pretreatment on graphene copper powder; Step 2, blank making: using a hot isostatic pressing blank making method to press the pretreated graphene copper powder in Step 1 into a shape to obtain a rod-shaped blank; Step 3, circular forging: drawing and forging the rod-shaped blank obtained in Step 2 into a copper rod; Step 4, wire drawing: using a wire drawing process to process the copper rod in Step 3 into a finished graphene copper wire.

2. The preparation method of a graphene copper wire according to claim 1, characterized in that The pretreatment process in Step 1 is as follows: drying commercially available pre-coated graphene copper powder in vacuum at 100°C for 3 h, and then sieving to obtain powder with a particle size not exceeding 50 μm.

3. The preparation method of a graphene copper wire according to claim 1, wherein The process of hot isostatic pressing in Step 2 is as follows: loading the pretreated graphene copper powder into a sheath, applying a pressure of 160 MPa to 200 MPa to the sheath and heating to 800°C to 850°C and maintaining for 3 h to 4 h.

4. The preparation method of a graphene copper wire according to claim 1, characterized in that, In Step 3, the rod-shaped blank is heated to 800°C to 850°C, and then multi-pass drawing and forging are performed to process and obtain a copper rod with the maximum diameter size that can pass through the die of a copper wire drawing machine.

5. The preparation method of a graphene copper wire according to claim 1, characterized in that, In Step 4, the copper rod is heated to 800°C to 850°C, and then multi-pass wire drawing is performed to process and obtain a finished graphene copper wire.

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