Preparation method of three-dimensional graphene / copper composite pipe

Abstract

The invention discloses a preparation method of a three-dimensional graphene / copper composite pipe, and belongs to the field of material processing. Three-dimensional graphene and a copper sheet are compounded, a three-dimensional graphene / copper composite blank is prepared through a laminated hot pressing method, the composite blank is forged and pressed into a composite bar, the composite bar is fed into an extruding machine to be heated and then extruded into a composite pipe, natural cooling is conducted, and finally the obtained composite pipe is subjected to surface treatment. Compared with traditional two-dimensional graphene, the three-dimensional graphene material adopted by the invention not only has the inherent physicochemical properties of graphene, but also has the excellent characteristics of large specific surface area, high mechanical strength, excellent electron conduction capability, high heat conductivity and the like due to the three-dimensional porous micro / nano structure of the three-dimensional graphene material. Compared with the prior art, the two-dimensional graphene has the advantages that the two-dimensional graphene has a porous structure and better pore connectivity, and stacking and aggregation of two-dimensional graphene sheet layers can be avoided to a certain extent, so that the dispersity of the two-dimensional graphene in different media is improved. According to the super red copper tube prepared by doping the three-dimensional graphene into the copper matrix, the conductivity, the heat-conducting property and the mechanical property of the super red copper tube can be remarkably improved while the excellent performance of red copper is kept.

Description

Technical Field

[0001] The invention relates to a preparation method of a three-dimensional graphene / copper composite pipe, and belongs to the field of material processing. Background Art

[0002] Copper and copper alloys are widely used in machinery, electrical, communication, transportation and microelectronics industries due to their excellent electrical and thermal conductivity, good ductility and corrosion resistance. With the rapid development of all walks of life, copper has higher and higher requirements in all aspects. Therefore, the development of copper-based composite materials with better electrical and thermal conductivity and high strength has become a hot topic today.

[0003] Since its discovery in 2004, graphene has attracted great attention in all fields of materials. Graphene is a two-dimensional structure. This two-dimensional structure is mechanically unstable and cannot be completely flat. There are still some wrinkles at the microscopic level. Such wrinkles will induce static electricity, so two-dimensional graphene is more likely to aggregate. In addition, there will be morphological defects such as cavities, edges, cracks, and heteroatoms on the surface of graphene, which will also affect the performance of graphene itself. Three-dimensional graphene materials not only have the inherent physical and chemical properties of graphene, but also have excellent characteristics such as large specific surface area, high mechanical strength, superior electronic conductivity, and rapid mass transfer due to their three-dimensional porous micro / nanostructure. Therefore, three-dimensional graphene has attracted more and more market attention due to its excellent performance and structural characteristics.

[0004] With the development of science and technology, higher and higher requirements are being placed on "high-strength and high-conductivity" copper-based composite materials. Three-dimensional graphene is considered to have significant application potential in copper-based composite materials due to its unique structure and properties, especially in the fields of electronics and automobiles. This new type of copper pipe, by adding three-dimensional graphene, not only inherits the excellent electrical and thermal conductivity of copper, but also exhibits more excellent comprehensive performance due to the addition of three-dimensional graphene. At present, there has been no report on copper pipes prepared by adding three-dimensional graphene to the copper matrix, so the development of a three-dimensional graphene / copper composite pipe is of great significance. Summary of the invention

[0005] In order to solve the above-mentioned problems, the present invention provides a method for preparing a three-dimensional graphene / copper composite pipe. A graphene dispersion is prepared, and the volume fraction of the three-dimensional graphene is determined by using a quantitative titration free diffusion method. The copper sheets composited with the graphene are stacked and hot-pressed, the prepared composite blank is forged into a rod, the rod is sent to an extruder for heating, and then extruded and formed, the extruded composite pipe is annealed, and finally surface treated to ensure its quality, so as to obtain a three-dimensional graphene / copper composite pipe with excellent performance.

[0006] The present invention specifically comprises the following steps:

[0007] Pretreatment of copper sheet: cut the copper sheet, soak it in dilute hydrochloric acid to remove the surface oxide layer, then soak it in anhydrous ethanol for ultrasonic treatment, and finally polish the surface of the copper sheet with sandpaper.

[0008] Configuration before three-dimensional graphene dispersion: weigh three-dimensional graphene powder with an electronic balance, pour anhydrous ethanol into a beaker, and then pour the weighed three-dimensional graphene powder into the beaker to mix and dissolve, so as to prepare a three-dimensional graphene dispersion.

[0009] Ultrasonic dispersion treatment: The three-dimensional graphene dispersion prepared in step (2) is placed in an ultrasonic instrument for ultrasonic dispersion. After each ultrasonic treatment for 30 minutes, the dispersion is allowed to stand for 5 minutes, and then the operation is repeated until the three-dimensional graphene dispersion is completely and evenly dispersed. The dispersion is then allowed to stand for a period of time to precipitate the three-dimensional graphene that is not completely ultrasonically dispersed, and the upper layer of the three-dimensional graphene dispersion and the lower layer of the suspension are separated.

[0010] Determination of the volume fraction of three-dimensional graphene: take out the upper dispersion and pour it into another beaker, measure the volumes of the upper dispersion and the lower suspension respectively, then dry the alcohol in the lower suspension, weigh the mass of the three-dimensional graphene, and thus determine the mass of the three-dimensional graphene in the upper dispersion. Finally, calculate the volume fraction of the three-dimensional graphene in the upper dispersion.

[0011] Composite of three-dimensional graphene dispersion and copper sheet: Take the upper layer of dispersion, pour it into the spray gun, spray the dispersion evenly on the surface of the copper sheet, and then put the copper sheet into an oven to dry.

[0012] Lamination hot pressing composite: The copper sheets dried in step (5) are stacked and then placed in a hot pressing machine. First, the initial pressure is set for cold pressing, and then the pressure and temperature are increased for hot pressing. During this period, the pressure and temperature are increased at regular intervals and maintained for a period of time. The operation is repeated to finally obtain a composite blank, which is then forged into a rod.

[0013] Extrusion molding: The rod is fed into the extruder for heating and then extruded to produce a composite pipe.

[0014] Annealing and surface treatment: Anneal the composite pipe to eliminate residual stress, and then perform surface treatment to ensure product surface quality.

[0015] Preferably, the high-purity oxygen-free copper sheet or electrolytic copper sheet used in step (1) of the present invention has a thickness of 0.1-1 mm.

[0016] Preferably, the mass fraction of the dilute hydrochloric acid used in step (1) of the present invention is 10-20%, and the soaking time is 5-10s.

[0017] Preferably, in step (3) of the present invention, the ultrasonic power is 120-180 W, the ultrasonic temperature range is 20-50° C., and the ultrasonic time is 1-2 h.

[0018] Preferably, the volume fraction of graphene in the graphene dispersion prepared in step (4) of the present invention is 0.5-1.5%.

[0019] Preferably, in step (5) of the present invention, the amount of the three-dimensional graphene dispersion on the copper sheet titrated by the rubber-tipped dropper is 0.1-0.5 ml / cm 2 .

[0020] Preferably, the temperature range of the hot pressing in step (6) of the present invention is 400-600° C., the pressure range is 40t-80t, and the time is 1-3h.

[0021] Preferably, in step (7) of the present invention, the heating temperature of the rod is 650° C., and the inner diameter of the obtained composite pipe is 2-8 mm and the wall thickness is 0.5-1 mm.

[0022] Preferably, in step (8) of the present invention, the annealing temperature of the composite pipe is 200-300° C., and the annealing time is 1-2 h.

[0023] Beneficial effects of the present invention: (1) The three-dimensional graphene used in the present invention has significant advantages in dispersibility compared to traditional two-dimensional graphene. Due to its sheet structure and strong intermolecular forces, such as polar chemical bonds and van der Waals forces, two-dimensional graphene tends to aggregate and is difficult to disperse evenly in a matrix such as a polymer. However, due to its three-dimensional closed, porous structure and better pore connectivity, three-dimensional graphene can avoid the stacking and aggregation of two-dimensional graphene sheets to a certain extent, thereby improving its dispersibility in different media. The three-dimensional graphene material not only has the inherent physical and chemical properties of graphene, but its three-dimensional porous micro / nano structure also enables it to have excellent characteristics such as large specific surface area, high mechanical strength, excellent electronic conductivity and rapid mass transfer. (2) The process method described in the present invention is simple, easy to operate and has low cost. The present invention adopts a stacking hot pressing method to combine the three-dimensional graphene with the copper sheet, thereby ensuring the integrity of the three-dimensional graphene structure. By precisely controlling the content and distribution of graphene, the thermal and electrical conductivity of copper tubes can be improved without sacrificing strength and plasticity to meet the needs of high-performance electronic devices. The high electrical and thermal conductivity of three-dimensional graphene can be used to improve the heat dissipation efficiency and performance stability of electronic devices, so this copper tube can be used for lead frames and thermal conductive materials for integrated circuits. In addition, the addition of three-dimensional graphene can also improve the electromagnetic shielding effectiveness of copper tubes and protect electronic devices from electromagnetic interference, which is particularly important for high-frequency electronic devices in 5G communication technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1It is a schematic diagram of the process flow of the present invention; Figure 2 This is the SEM image of the tensile fracture of the composite blank obtained in Example 1; Figure 3 This is the SEM image of the tensile fracture of the composite blank obtained in Example 2; Figure 4 This is the SEM image of the tensile fracture of the composite billet obtained in Example 3. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited to the contents described above.

[0026] Example 1 A method for preparing a three-dimensional graphene / copper composite material comprises the following steps:

[0027] (1) Pretreatment of copper foil: Cut the copper foil, soak it in 10% dilute hydrochloric acid for 10 seconds, then soak it in anhydrous ethanol for ultrasonic treatment, and finally polish the surface of the copper foil with sandpaper. This application uses high-purity oxygen-free copper foil with a thickness of 0.1 mm, a length of 1 m, and a width of 100 mm.

[0028] (2) Preparation before three-dimensional graphene dispersion: Weigh 0.02 g of three-dimensional graphene powder using an electronic balance. Pour 100 ml of anhydrous ethanol into a beaker, then pour the weighed three-dimensional graphene powder into the beaker to mix and dissolve, thereby preparing a three-dimensional graphene dispersion.

[0029] (3) Ultrasonic dispersion treatment: The three-dimensional graphene dispersion prepared in step (2) was placed in an ultrasonic instrument for ultrasonic dispersion. After each ultrasonic treatment for 30 minutes, the dispersion was allowed to stand for 5 minutes. This process was repeated 4 times, and the dispersion was then allowed to stand for 12 hours.

[0030] (4) Determination of the volume fraction of three-dimensional graphene: The upper dispersion was taken out and poured into another beaker. The volume of the upper dispersion was measured to be 30 ml and the volume of the lower suspension was 70 ml. The alcohol in the lower suspension was then dried and the mass of the three-dimensional graphene was weighed to be 0.015 g. The mass of the three-dimensional graphene in the upper dispersion was determined to be 0.005 g. The volume fraction of the three-dimensional graphene in the upper dispersion was calculated to be 0.75%.

[0031] (5) Composite of three-dimensional graphene dispersion and copper sheet: Take the upper layer of dispersion, pour it into the spray gun, spray the dispersion evenly on the surface of the copper sheet, and then put the copper sheet into an oven to dry.

[0032] (6) Lamination and hot pressing: 20 layers of copper foil dried in step (5) are stacked and then placed in a hot pressing machine. First, the initial pressure is set to 40t and the cold pressing time is 1h; then the pressure is increased to 50t, the temperature is heated to 400℃ and hot pressed for 1h; finally, the pressure is increased to 60t, the temperature is heated to 500℃ and hot pressed for 1h to obtain a three-dimensional graphene / copper composite blank. Multiple composite blanks are forged into 10cm long rods.

[0033] (7) Extrusion molding: The rod is fed into an extruder and heated at 650°C, and then extruded to produce a composite pipe with an inner diameter of 4 mm and a wall thickness of 0.5 mm.

[0034] (8) Annealing and surface treatment: The composite pipe is placed in a furnace for annealing at a temperature of 250 °C for 2 h to eliminate residual stress, and then the surface is polished to ensure the surface quality of the product.

[0035] (9) The conductivity of the prepared composite pipe was tested, and its conductivity was measured to be 100.2% IACS. The conductivity of the original copper sheet used was 96% IACS. The conductivity of the composite pipe was increased by 4.2% compared with the original copper sheet.

[0036] (10) The prepared composite pipe was subjected to a tensile performance test, and its tensile strength was measured to be 236 MPa. The tensile strength of the original copper sheet used was 220 MPa. The tensile strength of the composite pipe was increased by 7.3% compared with the original copper sheet.

[0037] (11) The thermal conductivity of the prepared composite pipe was tested, and its thermal conductivity was measured to be 428 W / (m·k). The thermal conductivity of the original copper sheet was 394 W / (m·k). The thermal conductivity of the composite pipe was increased by 8.6% compared with the original copper sheet.

[0038] Example 2 A method for preparing a three-dimensional graphene / copper composite material, comprising the following steps:

[0039] (1) Pretreatment of copper foil: Cut the copper foil, soak it in 10% dilute hydrochloric acid for 10 seconds, then soak it in anhydrous ethanol for ultrasonic treatment, and finally polish the surface of the copper foil with sandpaper. This application uses high-purity oxygen-free copper foil with a thickness of 0.1 mm, a length of 1 m, and a width of 100 mm.

[0040] (2) Preparation before three-dimensional graphene dispersion: Weigh 0.03 g of three-dimensional graphene powder using an electronic balance, pour 100 ml of anhydrous ethanol into a beaker, and then pour the weighed three-dimensional graphene powder into the beaker to mix and dissolve to prepare a three-dimensional graphene dispersion.

[0041] (3) Ultrasonic dispersion treatment: The three-dimensional graphene dispersion prepared in step (2) was placed in an ultrasonic instrument for ultrasonic dispersion. After each ultrasonic treatment for 30 minutes, the dispersion was allowed to stand for 5 minutes. This process was repeated 4 times, and then the dispersion was allowed to stand for 12 hours.

[0042] (4) Determination of the volume fraction of three-dimensional graphene: The upper dispersion was taken out and poured into another beaker. The volume of the upper dispersion was measured to be 30 ml and the volume of the lower suspension was 70 ml. The alcohol in the lower suspension was then dried and the mass of the three-dimensional graphene was weighed to be 0.023 g. The mass of the three-dimensional graphene in the upper dispersion was determined to be 0.007 g. The volume fraction of the three-dimensional graphene in the upper dispersion was calculated to be 1.06%.

[0043] (5) Composite of three-dimensional graphene dispersion and copper sheet: Take the upper layer of dispersion, pour it into the spray gun, spray the dispersion evenly on the surface of the copper sheet, and then put the copper sheet into an oven to dry.

[0044] (6) Lamination and hot pressing: 20 layers of copper foil dried in step (5) are stacked and then placed in a hot pressing machine. First, the initial pressure is set to 40t and the cold pressing time is 1h; then the pressure is increased to 50t, the temperature is heated to 400℃ and hot pressed for 1h; finally, the pressure is increased to 60t, the temperature is heated to 500℃ and hot pressed for 1h to obtain a three-dimensional graphene / copper composite blank. Multiple composite blanks are forged into 10cm long rods.

[0045] (7) Extrusion molding: The rod is fed into an extruder and heated at 650°C, and then extruded to produce a composite pipe with an inner diameter of 4 mm and a wall thickness of 0.5 mm.

[0046] (8) Annealing and surface treatment: The composite pipe is placed in a furnace for annealing at a temperature of 250 °C for 2 h to eliminate residual stress, and then the surface is polished to ensure the surface quality of the product.

[0047] (9) The conductivity of the prepared composite pipe was tested, and its conductivity was measured to be 101.8% IACS. The conductivity of the original copper sheet used was 96% IACS. The conductivity of the composite pipe was increased by 5.8% compared with the original copper sheet.

[0048] (10) The prepared composite pipe was subjected to a tensile performance test, and its tensile strength was measured to be 245 MPa. The tensile strength of the original copper sheet used was 220 MPa. The tensile strength of the composite pipe was increased by 11.4% compared with the original copper sheet.

[0049] (11) The thermal conductivity of the prepared composite pipe was tested, and its thermal conductivity was measured to be 434 W / (m·k). The thermal conductivity of the original copper sheet was 394 W / (m·k). The thermal conductivity of the composite pipe was increased by 10.2% compared with the original copper sheet.

[0050] Example 3 A method for preparing a three-dimensional graphene / copper composite material comprises the following steps:

[0051] (1) Pretreatment of copper foil: Cut the copper foil, soak it in 10% dilute hydrochloric acid for 10 seconds, then soak it in anhydrous ethanol for ultrasonic treatment, and finally polish the surface of the copper foil with sandpaper. This application uses high-purity oxygen-free copper foil with a thickness of 0.1 mm, a length of 1 m, and a width of 100 mm.

[0052] (2) Preparation before three-dimensional graphene dispersion: Weigh 0.04 g of three-dimensional graphene powder using an electronic balance, pour 100 ml of anhydrous ethanol into a beaker, and then pour the weighed three-dimensional graphene powder into the beaker to mix and dissolve to prepare a three-dimensional graphene dispersion.

[0053] (3) Ultrasonic dispersion treatment: The three-dimensional graphene dispersion prepared in step (2) was placed in an ultrasonic instrument for ultrasonic dispersion. After each ultrasonic treatment for 30 minutes, the dispersion was allowed to stand for 5 minutes. This process was repeated 4 times, and then the dispersion was allowed to stand for 12 hours.

[0054] (4) Determination of the volume fraction of three-dimensional graphene: The upper dispersion was taken out and poured into another beaker. The volume of the upper dispersion was measured to be 30 ml and the volume of the lower suspension was 70 ml. The alcohol in the lower suspension was then dried and the mass of the three-dimensional graphene was weighed to be 0.031 g. The mass of the three-dimensional graphene in the upper dispersion was determined to be 0.009 g. The volume fraction of the three-dimensional graphene in the upper dispersion was calculated to be 1.36%.

[0055] (5) Composite of three-dimensional graphene dispersion and copper sheet: Take the upper layer of dispersion, pour it into the spray gun, spray the dispersion evenly on the surface of the copper sheet, and then put the copper sheet into an oven to dry.

[0056] (6) Lamination and hot pressing: 20 layers of copper foil dried in step (5) are stacked and then placed in a hot pressing machine. First, the initial pressure is set to 40t and the cold pressing time is 1h; then the pressure is increased to 50t, the temperature is heated to 400℃ and hot pressed for 1h; finally, the pressure is increased to 60t, the temperature is heated to 500℃ and hot pressed for 1h to obtain a three-dimensional graphene / copper composite blank. Multiple composite blanks are forged into 10cm long rods.

[0057] (7) Extrusion molding: The rod is fed into an extruder and heated at 650°C, and then extruded to produce a composite pipe with an inner diameter of 4 mm and a wall thickness of 0.5 mm.

[0058] (8) Annealing and surface treatment: The composite pipe is placed in a furnace for annealing at a temperature of 250 °C for 2 h to eliminate residual stress, and then the surface is polished to ensure the surface quality of the product.

[0059] (9) The conductivity of the prepared composite pipe was tested, and its conductivity was measured to be 104.2% IACS. The conductivity of the original copper sheet used was 96% IACS. The conductivity of the composite pipe was increased by 8.2% compared with the original copper sheet.

[0060] (10) The prepared composite pipe was subjected to a tensile performance test, and its tensile strength was measured to be 255 MPa. The tensile strength of the original copper sheet used was 220 MPa. The tensile strength of the composite pipe was increased by 15.9% compared with the original copper sheet.

[0061] (11) The thermal conductivity of the prepared composite pipe was tested, and its thermal conductivity was measured to be 455 W / (m·k). The thermal conductivity of the original copper sheet was 394 W / (m·k). The thermal conductivity of the composite pipe was increased by 15.5% compared with the original copper sheet.

Claims

1. A method for preparing a three-dimensional graphene / copper composite tube, It is characterized in that The specific steps include: (1) Pretreatment of copper sheet: Cut the copper sheet, soak it in dilute hydrochloric acid to remove the surface oxide layer, then soak it in anhydrous ethanol for ultrasonic treatment, and finally polish the surface of the copper sheet with sandpaper; (2) Preparation before three-dimensional graphene dispersion: Weigh the three-dimensional graphene powder with an electronic balance, pour anhydrous ethanol into a beaker, and then pour the weighed three-dimensional graphene powder into the beaker to mix and dissolve to prepare a three-dimensional graphene dispersion; (3) Ultrasonic dispersion treatment: The three-dimensional graphene dispersion prepared in step (2) is placed in an ultrasonic instrument for ultrasonic dispersion. After each ultrasonic treatment for 30 minutes, the dispersion is allowed to stand for 5 minutes, and then the operation is repeated until the three-dimensional graphene dispersion is completely and evenly dispersed. The dispersion is then allowed to stand to precipitate the three-dimensional graphene that is not completely ultrasonically dispersed, and the upper layer of the three-dimensional graphene dispersion and the lower layer of the suspension are separated; (4) Determination of the volume fraction of three-dimensional graphene: Take out the upper dispersion and pour it into another beaker, measure the volumes of the upper dispersion and the lower suspension respectively, then dry the alcohol in the lower suspension, weigh the mass of the three-dimensional graphene, and thus determine the mass of the three-dimensional graphene in the upper dispersion. Finally, calculate the volume fraction of the three-dimensional graphene in the upper dispersion. (5) Composite of three-dimensional graphene dispersion and copper sheet: Take the upper layer of dispersion, pour it into the spray gun, spray the dispersion evenly on the surface of the copper sheet, and then put the copper sheet into an oven to dry; (6) Lamination and hot pressing: The copper sheets dried in step (5) are stacked and then placed in a hot pressing machine. First, the initial pressure is set for cold pressing, and then the pressure and temperature are increased for hot pressing. During this period, the pressure and temperature are increased at regular intervals and maintained for a period of time. The operation is repeated to finally obtain a composite blank, and then the composite blank is forged into a rod. (7) Extrusion molding: The rod is fed into an extruder for heating and then extruded to produce a composite pipe; (8) Annealing and surface treatment: Anneal the composite pipe to eliminate residual stress, and then perform surface treatment to ensure the surface quality of the product.

2. A method for preparing a three-dimensional graphene / copper composite pipe according to claim 1, Features: The high-purity oxygen-free copper sheet or electrolytic copper sheet used in step (1) has a thickness of 0.1-1 mm.

3. A method for preparing a three-dimensional graphene / copper composite pipe according to claim 1, Features: The mass fraction of the dilute hydrochloric acid used in step (1) is 10-20%, and the soaking time is 5-10s.

4. A method for preparing a three-dimensional graphene / copper composite pipe according to claim 3, Features: In the step (3), the ultrasonic power is 120-180 W, the ultrasonic temperature range is 20-50° C., and the ultrasonic time is 1-2 h.

5. A method for preparing a three-dimensional graphene / copper composite pipe according to claim 2, Features: The volume fraction of graphene in the graphene dispersion determined in step (4) is 0.5-1.5%.

6. A method for preparing a three-dimensional graphene / copper composite pipe according to claim 4, Features: The amount of the three-dimensional graphene dispersion sprayed on the copper sheet in step (5) is 0.1-0.5 ml / cm 2 .

7. A method for preparing a three-dimensional graphene / copper composite pipe according to claim 5, Features: The temperature range of the hot pressing in step (6) is 400-600° C., the pressure range is 40t-60t, and the time is 1-3h.

8. A method for preparing a three-dimensional graphene / copper composite pipe according to claim 6, Features: In the step (7), the heating temperature of the rod is 650° C., and the inner diameter of the obtained composite pipe is 2-8 mm and the wall thickness is 0.5-1 mm.

9. A method for preparing a three-dimensional graphene / copper composite pipe according to claim 7, Features: In the step (8), the annealing temperature of the composite pipe is 200-300° C., and the annealing time is 1-2 hours.

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