Interface regulation method of graphene copper composite material

Abstract

The application discloses an interface regulation method of graphene copper composite material, relates to the technical field of metal matrix composite material preparation, and aims to solve the problem of weak electron exchange between graphene and copper. The method comprises the following steps: S1, raw material selection; selecting a commercially available Gr / Cu / Gr foil as a substrate and selecting high-purity metal particles as an evaporation target; S2, metal deposition; depositing a heterogeneous metal layer with different thicknesses on both sides of the substrate by using a vacuum thermal evaporation film coating process, so that the substrate is wrapped by the heterogeneous metal layer; S3, metal deposition pretreatment; performing heat annealing treatment on the substrate obtained in the step S2, so that a heterogeneous metal coating with high crystallinity is obtained; S4, stacking a plurality of the substrates treated in the step S3, so as to construct an interface structure conducive to electric conduction; and finally, the graphene copper block material with high conductivity is prepared by using a vacuum hot pressing forming process.

Description

Technical Field

[0001] The present invention relates to the technical field of preparation of metal-based composite materials, and in particular to a method for controlling the interface of a graphene-copper composite material. Background Art

[0002] Copper-based composites are widely used in electronics, aerospace, and traditional industries due to their excellent electrical and thermal conductivity and good processing properties. In recent years, as research on graphene has deepened, its various unique physical properties have been discovered.

[0003] Due to its high strength and high carrier mobility, graphene is expected to serve as a reinforcement for copper-based composites, further improving their electrical conductivity and surpassing the conductivity limits of traditional copper-based materials. Ultra-high conductive copper refers to copper-based composites with electrical conductivity exceeding 100% IACS. This has driven developments in the electronics and energy sectors.

[0004] Currently, there are two main methods for manipulating the interface structure of graphene-copper composites. First, SPS reduces the content of impurities such as oxygen at the graphene-copper interface to improve interface cleanliness. Second, powder metallurgy is used to mix in metal powders that bond well with graphene, followed by hot pressing and sintering to produce bulk materials. The added metal effectively strengthens the bond between graphene and copper, promoting electron exchange.

[0005] Although the above two methods can play a role in improving the conductive properties, they can no longer guarantee a continuous conductive channel and promote electron exchange. Summary of the Invention

[0006] The present invention provides a method for controlling the interface of a graphene-copper composite material, which comprises the following steps:

[0007] S1: Raw material selection: select commercially available Gr / Cu / Gr foil as the substrate and high-purity metal particles as the evaporation target;

[0008] S2: depositing metal; depositing heterogeneous metal layers of different thicknesses on both sides of the substrate using a vacuum thermal evaporation coating process to obtain the substrate wrapped by the heterogeneous metal layers;

[0009] S3: Pretreatment of deposited metal: performing thermal annealing on the substrate obtained in step S2 to obtain a heterogeneous metal coating with high crystallinity;

[0010] S4: stacking multiple substrates processed in step S3 to construct an interface structure that is conducive to conductivity, and then performing a vacuum hot pressing process to prepare a highly conductive graphene copper block material.

[0011] The present invention is further configured as follows: in the thermal evaporation coating process in step S2, the vacuum degree is controlled at ≤1×10 -5 Pa, and the evaporation rate was controlled at 0.1 nm / s.

[0012] The present invention is further configured as follows: in step S2, the thickness of the heterogeneous metal layer is controlled to be 20-100 nm.

[0013] The present invention is further configured as follows: the thermal annealing treatment in step S3 is carried out in a heat treatment furnace, and an argon atmosphere is maintained in the heat treatment furnace; for heterogeneous metals with a melting point higher than copper, the annealing temperature is controlled at 783-983°C; for heterogeneous metals with a melting point lower than copper, the annealing temperature is controlled at 883-983°C; and the annealing time is controlled at 30-150 min.

[0014] The present invention is further configured as follows: in the vacuum hot pressing process in step S4, the vacuum degree is controlled at ≤1×10 -4 Pa; the hot pressing pressure is controlled at 50MPa, the hot pressing temperature is controlled at 1000℃, the holding time is 60min, and the holding time is 60min.

[0015] The present invention also provides a method for controlling the interface of a graphene-copper composite material, which comprises the following steps:

[0016] S1: Raw material selection: select commercially available Gr / Cu / Gr / foil as the substrate and high-purity metal particles as the evaporation target;

[0017] S2: depositing metal; depositing heterogeneous metal layers of different thicknesses on both sides of the substrate using an electron beam evaporation coating process to obtain a substrate wrapped with the heterogeneous metal layers;

[0018] S3: Pretreatment of deposited metal: performing thermal annealing on the substrate obtained in step S2 to obtain a heterogeneous metal coating with high crystallinity;

[0019] S4: stacking a plurality of substrates processed in step S3 to construct an interface structure conducive to electrical conductivity, and then preparing a highly conductive graphene copper bulk material through a vacuum hot pressing process.

[0020] The present invention is further configured as follows: in the electron beam evaporation process in step S2, the vacuum degree is controlled at ≤1×10 - 5 Pa, the fixed evaporation rate is 0.1 nm / s, the evaporation distance is 50 cm, the electron gun voltage is 10 KV, and the substrate temperature is 25 °C.

[0021] The present invention is further configured as follows: in step S2, the thickness of the heterogeneous metal layer is controlled to be 20-100 nm.

[0022] The present invention is further configured as follows: the thermal annealing treatment in step S3 is carried out in a heat treatment furnace, and an argon atmosphere is maintained in the heat treatment furnace; for heterogeneous metals with a melting point higher than copper, the annealing temperature is controlled at 783-983°C; for heterogeneous metals with a melting point lower than copper, the annealing temperature is controlled at 883-983°C; and the annealing time is controlled at 30-150 min.

[0023] The present invention is further configured as follows: in the vacuum hot pressing process in step S4, the vacuum degree is controlled at 1×10 -4 Pa; the hot pressing pressure is controlled at 50MPa, the hot pressing temperature is controlled at 1000℃, the holding time is 60min, and the holding time is 60min.

[0024] The beneficial effects of this invention are as follows: the process flow employed by the invention ensures the continuous distribution of heterogeneous atomic layers. Driven by differences in work functions, the charge of the interface auxiliary components is redistributed, forming interface dipoles, which alter the material's band structure, create new electron transition pathways, and construct new conductive channels, thereby improving the conductivity of the composite material. Currently, the conductivity of the composite material prepared using this method can reach 118.4% IACS. This means that the weight and volume of the wire can be reduced while maintaining the same conductivity requirements, which can promote the lightweighting of the wire. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The process flow diagram of Example 1 is shown.

[0026] Figure 2 The conductivity of different evaporation targets is shown.

[0027] Figure 3 The conductivity of metal layers deposited at different thicknesses is shown.

[0028] Figure 4 The Raman spectrum of graphene after silver coating is shown.

[0029] Figure 5 The Raman spectrum of unsilvered graphene is shown.

[0030] Figure 6 A process flow diagram of Example 8 is shown. DETAILED DESCRIPTION

[0031] Those skilled in the art can refer to the content of this article and appropriately improve the process parameters. It is particularly important to point out that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in the present invention. The methods and applications of the present invention have been described through preferred embodiments. Relevant persons can modify or appropriately change and combine the methods and applications described herein without departing from the content, spirit and scope of the present invention to implement and apply the technology of the present invention.

[0032] Example 1

[0033] The present invention provides a method for controlling the interface of a graphene-copper composite material, comprising the following steps:

[0034] S1: Raw material selection: select commercially available Gr / Cu / Gr foil as the substrate and high-purity metal particles as the evaporation target;

[0035] S2: depositing metal; depositing heterogeneous metal layers of different thicknesses on both sides of the substrate using a vacuum evaporation coating process to obtain the substrate wrapped by the heterogeneous metal layers;

[0036] S3: Pretreatment of deposited metal: performing thermal annealing on the substrate obtained in step S2 to obtain a heterogeneous metal coating with high crystallinity;

[0037] S4: stacking multiple substrates processed in step S3 to construct an interface structure that is conducive to conductivity, and then performing a vacuum hot pressing process to prepare a highly conductive graphene copper block material.

[0038] The vacuum degree of the thermal evaporation coating process in step S2 is controlled at ≤1×10 -5 Pa, the evaporation rate is controlled at 0.1 nm / s, and the thickness of the heterogeneous metal layer is controlled at 20-100 nm.

[0039] The thermal annealing treatment in step S3 is performed in a heat treatment furnace, and an argon atmosphere is maintained in the heat treatment furnace; for heterogeneous metals with a melting point higher than copper, the annealing temperature is controlled at 783-983°C, that is, the melting point of copper is 1083°C, and the annealing temperature is controlled at 100-300°C below the melting point of copper; for heterogeneous metals with a melting point lower than copper, the annealing temperature is controlled at 883-983°C, that is, the annealing temperature is controlled at 100-200°C below the melting point of copper; and the annealing time is controlled at 30-150 minutes.

[0040] The vacuum hot pressing process in step S4 is controlled at a vacuum degree of 1×10 -4 Pa; the hot pressing pressure is controlled at 50MPa, the hot pressing temperature is controlled at 1000℃, the holding time is 60min, and the holding time is 60min.

[0041] It should be noted that the evaporation target material in step S1 is mainly divided into three categories, one is magnetic metal such as nickel, cobalt, the second is physical adsorption metal such as silver, aluminum, and the third is chemical adsorption metal such as titanium, chromium.

[0042] It should also be noted that the interface structure after stacking in step S4 is Cu / Gr / M / Gr / Cu, wherein M represents the deposited heterogeneous metal plating layer.

[0043] Example 2

[0044] The present embodiment adopts the method disclosed in Example 1 to regulate the interface of graphene copper composite material, which specifically includes the following steps:

[0045] S1: raw material selection; select commercially available Gr / Cu / Gr foil as the substrate, the selected foil thickness is 25μm, and select silver particles with a purity of 99.99% as the evaporation target material;

[0046] S2: depositing metal; fix the substrate selected in step S1 above the evaporation source, and start plating when the vacuum degree of the thermal evaporation system is reduced to 1×10 -5 Pa, and fix the evaporation rate at 0.1nm / s. Slowly deposit a 20nm silver layer on both surfaces of the substrate to obtain a substrate wrapped in a silver layer. By characterizing the silver-plated substrate, as shown in FIGS. Figure 4 、 5 The Raman spectrum of graphene after silver plating shows a tendency of G peak blue shift and 2D peak red shift compared with the Raman spectrum without silver plating, indicating that graphene is doped with electrons, and electrons are transmitted through the conductive path of graphene;

[0047] S3: depositing metal pretreatment; place the substrate wrapped in a silver layer obtained in step S2 into a heat treatment furnace, and after the vacuum degree is reduced to below 1Pa, introduce argon until the heat treatment furnace reaches atmospheric pressure, and then repeat the vacuum reduction to ensure that the heat treatment furnace is in an oxygen-free environment, i.e. to achieve the purpose of gas washing in the heat treatment furnace, set the heating rate to 15℃ / min, the holding temperature to 800℃, and the holding time to 60min, and then cool down. After cooling, a silver plating layer with high crystallinity is obtained. The cooling method is furnace cooling.

[0048] S4: stack multiple silver-wrapped substrates, and place them in a graphite mold of a hot pressing furnace, set the heating rate to 15℃ / min, the hot pressing temperature to 1000℃, and the holding time to 60min, the pressure rising time is synchronized with the temperature rising time, the hot pressing pressure is 50MPa, the pressure holding time is 60min, and after cooling to room temperature in the furnace, the sample is taken and the surface graphite is polished off, the Van der Pauw conductivity test is performed, and a copper sheet with a conductivity of 116.6%IACS and a size of 2cm×2cm×0.5cm is obtained.

[0049] Example 3

[0050] This embodiment adopts the method disclosed in Example 1 to regulate the interface of the graphene copper composite material, which specifically includes the following steps:

[0051] S1: Raw material selection: select commercially available Gr / Cu / Gr foil as the substrate, the selected foil thickness is 25μm, and silver particles with a purity of 99.99% are selected as the evaporation target;

[0052] S2: Deposit metal; fix the substrate selected in step S1 above the evaporation source, and wait for the vacuum degree of the thermal evaporation system to drop to 1×10 -5 Pa started coating with a fixed evaporation rate of 0.1 nm / s. A 40 nm silver layer was slowly deposited on both surfaces of the substrate to obtain a substrate covered with the silver layer.

[0053] S3: Pretreatment of deposited metal: The silver-coated substrate obtained in step S2 is placed in a heat treatment furnace, evacuated to below 1 Pa, and then argon gas is introduced until the heat treatment furnace reaches atmospheric pressure. Vacuuming is then continued multiple times to ensure that the heat treatment furnace is in an oxygen-free environment, that is, to achieve the purpose of purging the heat treatment furnace. The heating rate is set to 15°C / min, the holding temperature is set to 600°C, and the holding time is set to 60 minutes. After cooling, a silver coating with high crystallinity is obtained. The cooling method is furnace cooling.

[0054] S4: Multiple silver-wrapped substrates were stacked and placed in a graphite mold in a hot pressing furnace. The heating rate was set to 15°C / min, the hot pressing temperature was set to 1000°C, the holding time was set to 60 minutes, the pressing time and the heating time were carried out simultaneously, the hot pressing pressure was 50 MPa, and the holding time was 60 minutes. After cooling to room temperature with the furnace, samples were taken and the surface graphite was polished off. The Van der Pauw conductivity test was performed to obtain a copper sheet with a conductivity of 118.4% IACS and a size of 2 cm × 2 cm × 0.5 cm.

[0055] Example 4

[0056] This embodiment adopts the method disclosed in Example 1 to regulate the interface of the graphene copper composite material, which specifically includes the following steps:

[0057] S1: Raw material selection: select commercially available Gr / Cu / Gr foil as the substrate, the selected foil thickness is 25μm, and silver particles with a purity of 99.99% are selected as the evaporation target;

[0058] S2: Deposit metal; fix the substrate selected in step S1 above the evaporation source, and wait for the vacuum degree of the thermal evaporation system to drop to 1×10 -5Pa started coating with a fixed evaporation rate of 0.1 nm / s. A 100 nm thick silver layer was slowly deposited on both surfaces of the substrate to obtain a substrate covered with the silver layer.

[0059] S3: Pretreatment of deposited metal: The silver-coated substrate obtained in step S2 is placed in a heat treatment furnace, evacuated to below 1 Pa, and then argon gas is introduced until the heat treatment furnace reaches atmospheric pressure. Vacuuming is then continued multiple times to ensure that the heat treatment furnace is in an oxygen-free environment, that is, to achieve the purpose of purging the heat treatment furnace. The heating rate is set to 15°C / min, the holding temperature is set to 600°C, and the holding time is set to 60 minutes. After cooling, a silver coating with high crystallinity is obtained. The cooling method is furnace cooling.

[0060] S4: Multiple silver-wrapped substrates were stacked and placed in a graphite mold in a hot pressing furnace. The heating rate was set to 15°C / min, the hot pressing temperature was set to 1000°C, the holding time was set to 60 minutes, the pressing time and the heating time were carried out simultaneously, the hot pressing pressure was 50 MPa, and the holding time was 60 minutes. After cooling to room temperature with the furnace, samples were taken and the surface graphite was polished off. The Van der Pauw conductivity test was performed to obtain a copper sheet with a conductivity of 114.32% IACS and a size of 2 cm × 2 cm × 0.5 cm.

[0061] Example 5

[0062] This embodiment adopts the method disclosed in Example 1 to regulate the interface of the graphene copper composite material, which specifically includes the following steps:

[0063] S1: Raw material selection: select commercially available Gr / Cu / Gr foil as the substrate, the selected foil thickness is 25μm, and chromium particles with a purity of 99.99% are selected as the evaporation target;

[0064] S2: Deposit metal; fix the substrate selected in step S1 above the evaporation source, and wait for the vacuum degree of the thermal evaporation system to drop to 1×10 -5 Pa started coating with a fixed evaporation rate of 0.1 nm / s. A 20 nm chromium layer was slowly deposited on both surfaces of the substrate to obtain a substrate covered with the chromium layer.

[0065] S3: Pretreatment of deposited metal: The substrate coated with the chromium layer obtained in step S2 is placed in a heat treatment furnace, evacuated to below 1 Pa, and then argon gas is introduced until the heat treatment furnace reaches atmospheric pressure. Vacuuming is then continued multiple times to ensure that the heat treatment furnace is in an oxygen-free environment, that is, to achieve the purpose of purging the heat treatment furnace. The heating rate is set to 15°C / min, the holding temperature is 800°C, and the holding time is 60 minutes. The heat treatment furnace is then cooled to obtain a chromium coating with high crystallinity. The cooling method is furnace cooling.

[0066] S4: Multiple chromium-wrapped substrates were stacked and placed in a graphite mold in a hot pressing furnace. The heating rate was set to 15°C / min, the hot pressing temperature was set to 1000°C, the holding time was set to 60 minutes, the pressing time and the heating time were carried out simultaneously, the hot pressing pressure was 50 MPa, and the holding time was 60 minutes. After cooling to room temperature with the furnace, samples were taken and the surface graphite was polished off. The Van der Pauw conductivity test was performed to obtain a copper sheet with a conductivity of 113.8% IACS and a size of 2 cm × 2 cm × 0.5 cm.

[0067] Example 6

[0068] This embodiment adopts the method disclosed in Example 1 to regulate the interface of the graphene copper composite material, which specifically includes the following steps:

[0069] S1: Raw material selection: select commercially available Gr / Cu / Gr foil as the substrate, the selected foil thickness is 25μm, and nickel particles with a purity of 99.99% are selected as the evaporation target;

[0070] S2: Deposit metal; fix the substrate selected in step S1 above the evaporation source, and wait for the vacuum degree of the thermal evaporation system to drop to 1×10 -5 Pa started coating with a fixed evaporation rate of 0.1 nm / s. A 20 nm nickel layer was slowly deposited on both surfaces of the substrate to obtain a substrate covered with the nickel layer.

[0071] S3: Pretreatment of deposited metal: The nickel-coated substrate obtained in step S2 is placed in a heat treatment furnace, evacuated to below 1 Pa, and then argon gas is introduced until the heat treatment furnace reaches atmospheric pressure. Vacuuming is then continued multiple times to ensure that the heat treatment furnace is in an oxygen-free environment, that is, to achieve the purpose of purging the heat treatment furnace. The heating rate is set to 15°C / min, the holding temperature is 800°C, the holding time is 60 minutes, and then cooling is performed to obtain a nickel coating with high crystallinity. The cooling method is furnace cooling.

[0072] S4: Multiple nickel-wrapped substrates were stacked and placed in a graphite mold in a hot pressing furnace. The heating rate was set to 15°C / min, the hot pressing temperature was set to 1000°C, the holding time was set to 60 minutes, the pressing time and the heating time were carried out simultaneously, the hot pressing pressure was 50 MPa, and the holding time was 60 minutes. After cooling to room temperature with the furnace, samples were taken and the surface graphite was polished off. The Van der Pauw conductivity test was performed to obtain a copper sheet with a conductivity of 112.4% IACS and a size of 2 cm × 2 cm × 0.5 cm.

[0073] Example 7

[0074] This embodiment adopts the method disclosed in Example 1 to regulate the interface of the graphene copper composite material, which specifically includes the following steps:

[0075] S1: Raw material selection: select commercially available Gr / Cu / Gr foil as the substrate, the selected foil thickness is 25μm, and aluminum particles with a purity of 99.99% are selected as the evaporation target;

[0076] S2: Deposit metal; fix the substrate selected in step S1 above the evaporation source, and wait for the vacuum degree of the thermal evaporation system to drop to 1×10 -5 Pa started coating with a fixed evaporation rate of 0.1 nm / s. A 20 nm thick aluminum layer was slowly deposited on both surfaces of the substrate to obtain a substrate covered with the aluminum layer.

[0077] S3: Pretreatment of deposited metal: The aluminum-coated substrate obtained in step S2 is placed in a heat treatment furnace, evacuated to below 1 Pa, and then argon gas is introduced until the heat treatment furnace reaches atmospheric pressure. Vacuuming is then continued multiple times to ensure an oxygen-free environment in the heat treatment furnace, i.e., to achieve the purpose of purging the heat treatment furnace. The heating rate is set to 15°C / min, the holding temperature is set to 600°C, and the holding time is set to 60 minutes. Cooling is then performed to obtain a highly crystalline aluminum coating. The cooling method is furnace cooling.

[0078] S4: Multiple aluminum-wrapped substrates were stacked and placed in a graphite mold in a hot pressing furnace. The heating rate was set to 15°C / min, the hot pressing temperature was set to 1000°C, the holding time was set to 60 minutes, the pressing time and the heating time were carried out simultaneously, the hot pressing pressure was 50 MPa, and the holding time was 60 minutes. After cooling to room temperature with the furnace, samples were taken and the surface graphite was polished off. The Van der Pauw conductivity test was performed to obtain a copper sheet with a conductivity of 114.5% IACS and a size of 2 cm × 2 cm × 0.5 cm.

[0079] Example 8

[0080] The present invention also proposes a method for controlling the interface of a graphene-copper composite material, comprising the following steps:

[0081] S1: Raw material selection: select commercially available Gr / Cu / Gr foil as the substrate and high-purity metal particles as the evaporation target;

[0082] S2: Depositing metal; depositing heterogeneous metal layers of different thicknesses on both sides of the substrate using an electron beam evaporation coating process to obtain a substrate wrapped with heterogeneous metal layers;

[0083] S3: Pretreatment of deposited metal: performing thermal annealing on the substrate obtained in step S2 to obtain a heterogeneous metal coating with high crystallinity;

[0084] S4: Stack multiple substrates treated in step S3, build an interface structure conducive to electrical conduction, and then obtain a high-conductive graphene copper block material by vacuum hot pressing process.

[0085] In step S2, the vacuum degree of the electron beam evaporation process is controlled to be ≤1×10 -5 Pa, the fixed evaporation rate is 0.1 nm / s, the evaporation distance is 50 cm, the electron gun voltage is 10 KV, and the substrate temperature is 35℃. The thickness of the heterogeneous metal layer is controlled to be 20-100 nm.

[0086] In step S3, the heat annealing process is performed in a heat treatment furnace with an argon atmosphere. For the heterogeneous metal with a melting point higher than copper, the annealing temperature is controlled to be 783-983℃, i.e., the annealing temperature is controlled to be 100-300℃ below the melting point of copper. For the heterogeneous metal with a melting point lower than copper, the annealing temperature is controlled to be 883-983℃, i.e., the annealing temperature is controlled to be 100-200℃ below the melting point of copper. The annealing time is controlled to be 30-150 min.

[0087] In step S4, the vacuum hot pressing process has a vacuum degree of 1×10 -4 Pa, a hot pressing pressure of 50 MPa, a hot pressing temperature of 1000℃, a holding time of 60 min, and a pressure holding time of 60 min.

[0088] It should be noted that the evaporation target material in step S1 is mainly divided into three categories: the first is magnetic metal, such as nickel and cobalt; the second is physical adsorption metal, such as silver and aluminum; and the third is chemical adsorption metal, such as titanium and chromium.

[0089] It should also be noted that the stacked interface structure in step S4 is Cu / Gr / M / Gr / Cu, where M represents the deposited heterogeneous metal plating layer.

[0090] Example 9

[0091] This embodiment uses the method disclosed in Example 8 to regulate the interface of graphene copper composite material, which specifically includes the following steps:

[0092] S1: Raw material selection; select commercially available Gr / Cu / Gr foil as the substrate, the selected foil thickness is 25μm, and select silver particles with a purity of 99.99% as the evaporation target material;

[0093] S2: Metal deposition; fix the substrate selected in step S1 above the evaporation source, and control the vacuum degree of the electron beam evaporation system to be 1×10 -5Pa started coating, fixed evaporation rate of 0.1nm / s, evaporation distance of 50cm, electron gun voltage of 10KV, substrate temperature of 25℃. Slowly deposited 20nm silver layer on both surfaces of the substrate to obtain a substrate covered with silver layer. By characterizing the silver-plated substrate, such as Figure 4 、 5 As shown in the figure, the Raman spectrum of the silver-plated graphene shows a tendency of blue shift of the G peak and red shift of the 2D peak compared with the unsilver-plated graphene, indicating that the graphene is doped with electrons and the electrons are transmitted through the graphene as a conductive path;

[0094] S3: Pretreatment of deposited metal: The silver-coated substrate obtained in step S2 is placed in a heat treatment furnace, evacuated to below 1 Pa, and then argon gas is introduced until the heat treatment furnace reaches atmospheric pressure. Vacuuming is then continued multiple times to ensure that the heat treatment furnace is in an oxygen-free environment, that is, to achieve the purpose of purging the heat treatment furnace. The heating rate is set to 15°C / min, the holding temperature is 800°C, and the holding time is 60 minutes. The heat treatment furnace is then cooled to obtain a silver coating with high crystallinity. The cooling method is furnace cooling.

[0095] S4: Multiple silver-wrapped substrates were stacked and placed in a graphite mold in a hot pressing furnace. The heating rate was set to 15°C / min, the hot pressing temperature was set to 1000°C, the holding time was set to 60 minutes, the pressing time and the heating time were carried out simultaneously, the hot pressing pressure was 50 MPa, and the holding time was 60 minutes. After cooling to room temperature with the furnace, samples were taken and the surface graphite was polished off. The Van der Pauw conductivity test was performed to obtain a copper sheet with a conductivity of 116.6% IACS and a size of 2 cm × 2 cm × 0.5 cm.

[0096] Example 10

[0097] This embodiment adopts the method disclosed in Example 8 to regulate the interface of the graphene copper composite material, which specifically includes the following steps:

[0098] S1: Raw material selection: select commercially available Gr / Cu / Gr foil as the substrate, the selected foil thickness is 25μm, and silver particles with a purity of 99.99% are selected as the evaporation target;

[0099] S2: Deposit metal; fix the substrate selected in step S1 above the evaporation source, and wait until the vacuum degree of the electron beam evaporation system is 1×10 -5 Pa started coating with a fixed evaporation rate of 0.1 nm / s, an evaporation distance of 50 cm, an electron gun voltage of 10 kV, and a substrate temperature of 25 ° C. A 40 nm silver layer was slowly deposited on both surfaces of the substrate to obtain a substrate covered with a silver layer.

[0100] S3: Pretreatment of deposited metal: The silver-coated substrate obtained in step S2 is placed in a heat treatment furnace, evacuated to below 1 Pa, and then argon gas is introduced until the heat treatment furnace reaches atmospheric pressure. Vacuuming is then continued multiple times to ensure that the heat treatment furnace is in an oxygen-free environment, that is, to achieve the purpose of purging the heat treatment furnace. The heating rate is set to 15°C / min, the holding temperature is 800°C, and the holding time is 60 minutes. The heat treatment furnace is then cooled to obtain a silver coating with high crystallinity. The cooling method is furnace cooling.

[0101] S4: Multiple silver-wrapped substrates were stacked and placed in a graphite mold in a hot pressing furnace. The heating rate was set to 15°C / min, the hot pressing temperature was set to 1000°C, the holding time was set to 60 minutes, the pressing time and the heating time were carried out simultaneously, the hot pressing pressure was 50 MPa, and the holding time was 60 minutes. After cooling to room temperature with the furnace, samples were taken and the surface graphite was polished off. The Van der Pauw conductivity test was performed to obtain a copper sheet with a conductivity of 118.4% IACS and a size of 2 cm × 2 cm × 0.5 cm.

[0102] Example 11

[0103] This embodiment adopts the method disclosed in Example 8 to regulate the interface of the graphene copper composite material, which specifically includes the following steps:

[0104] S1: Raw material selection: select commercially available Gr / Cu / Gr foil as the substrate, the selected foil thickness is 25μm, and silver particles with a purity of 99.99% are selected as the evaporation target;

[0105] S2: Deposit metal; fix the substrate selected in step S1 above the evaporation source, and wait until the vacuum degree of the electron beam evaporation system is 1×10 -5 Pa started coating with a fixed evaporation rate of 0.1 nm / s, an evaporation distance of 50 cm, an electron gun voltage of 10 kV, and a substrate temperature of 25 ° C. A 100 nm silver layer was slowly deposited on both surfaces of the substrate to obtain a substrate covered with a silver layer.

[0106] S3: Pretreatment of deposited metal: The silver-coated substrate obtained in step S2 is placed in a heat treatment furnace, evacuated to below 1 Pa, and then argon gas is introduced until the heat treatment furnace reaches atmospheric pressure. Vacuuming is then continued multiple times to ensure that the heat treatment furnace is in an oxygen-free environment, that is, to achieve the purpose of purging the heat treatment furnace. The heating rate is set to 15°C / min, the holding temperature is 800°C, and the holding time is 60 minutes. The heat treatment furnace is then cooled to obtain a silver coating with high crystallinity. The cooling method is furnace cooling.

[0107] S4: Multiple silver-wrapped substrates were stacked and placed in a graphite mold in a hot pressing furnace. The heating rate was set to 15°C / min, the hot pressing temperature was 1000°C, the holding time was 60 minutes, the pressing time and the heating time were carried out simultaneously, the hot pressing pressure was 50 MPa, and the holding time was 60 minutes. After cooling to room temperature with the furnace, samples were taken and the surface graphite was polished off. The Van der Pauw conductivity test was performed to obtain a copper sheet with a conductivity of 114.32% IACS and a size of 2 cm × 2 cm × 0.5 cm.

[0108] Example 12

[0109] This embodiment adopts the method disclosed in Example 8 to regulate the interface of the graphene copper composite material, which specifically includes the following steps:

[0110] S1: Raw material selection: select commercially available Gr / Cu / Gr foil as the substrate, the selected foil thickness is 25μm, and chromium particles with a purity of 99.99% are selected as the evaporation target;

[0111] S2: Deposit metal; fix the substrate selected in step S1 above the evaporation source, and wait until the vacuum degree of the electron beam evaporation system is 1×10 -5 Pa started film deposition with a fixed evaporation rate of 0.1 nm / s, an evaporation distance of 50 cm, an electron gun voltage of 10 kV, and a substrate temperature of 25 ° C. A 20 nm chromium layer was slowly deposited on both surfaces of the substrate to obtain a substrate covered with a chromium layer;

[0112] S3: Pretreatment of deposited metal: The substrate coated with the chromium layer obtained in step S2 is placed in a heat treatment furnace, evacuated to below 1 Pa, and then argon gas is introduced until the heat treatment furnace reaches atmospheric pressure. Vacuuming is then continued multiple times to ensure that the heat treatment furnace is in an oxygen-free environment, that is, to achieve the purpose of purging the heat treatment furnace. The heating rate is set to 15°C / min, the holding temperature is 800°C, and the holding time is 60 minutes. The heat treatment furnace is then cooled to obtain a chromium coating with high crystallinity. The cooling method is furnace cooling.

[0113] S4: Multiple chromium-wrapped substrates were stacked and placed in a graphite mold in a hot pressing furnace. The heating rate was set to 15°C / min, the hot pressing temperature was set to 1000°C, the holding time was set to 60 minutes, the pressing time and the heating time were carried out simultaneously, the hot pressing pressure was 50 MPa, and the holding time was 60 minutes. After cooling to room temperature with the furnace, samples were taken and the surface graphite was polished off. The Van der Pauw conductivity test was performed to obtain a copper sheet with a conductivity of 113.8% IACS and a size of 2 cm × 2 cm × 0.5 cm.

[0114] Example 13

[0115] This embodiment adopts the method disclosed in Example 8 to regulate the interface of the graphene copper composite material, which specifically includes the following steps:

[0116] S1: Raw material selection: select commercially available Gr / Cu / Gr foil as the substrate, the selected foil thickness is 25μm, and nickel particles with a purity of 99.99% are selected as the evaporation target;

[0117] S2: Deposit metal; fix the substrate selected in step S1 above the evaporation source, and wait until the vacuum degree of the electron beam evaporation system is 1×10 -5 Pa started film deposition with a fixed evaporation rate of 0.1 nm / s, an evaporation distance of 50 cm, an electron gun voltage of 10 kV, and a substrate temperature of 25 ° C. A 20 nm nickel layer was slowly deposited on both surfaces of the substrate to obtain a substrate covered with a nickel layer;

[0118] S3: Pretreatment of deposited metal: The substrate coated with the chromium layer obtained in step S2 is placed in a heat treatment furnace, evacuated to below 1 Pa, and then argon gas is introduced until the heat treatment furnace reaches atmospheric pressure. Vacuuming is then continued multiple times to ensure that the heat treatment furnace is in an oxygen-free environment, that is, to achieve the purpose of purging the heat treatment furnace. The heating rate is set to 15°C / min, the holding temperature is 800°C, and the holding time is 60 minutes. The heat treatment furnace is then cooled to obtain a nickel coating with high crystallinity. The cooling method is furnace cooling.

[0119] S4: Multiple nickel-wrapped substrates were stacked and placed in a graphite mold in a hot pressing furnace. The heating rate was set to 15°C / min, the hot pressing temperature was set to 1000°C, the holding time was set to 60 minutes, the pressing time and the heating time were carried out simultaneously, the hot pressing pressure was 50 MPa, and the holding time was 60 minutes. After cooling to room temperature with the furnace, samples were taken and the surface graphite was polished off. The Van der Pauw conductivity test was performed to obtain a copper sheet with a conductivity of 112.4% IACS and a size of 2 cm × 2 cm × 0.5 cm.

[0120] Example 14

[0121] This embodiment adopts the method disclosed in Example 8 to regulate the interface of the graphene copper composite material, which specifically includes the following steps:

[0122] S1: Raw material selection: select commercially available Gr / Cu / Gr foil as the substrate, the selected foil thickness is 25μm, and aluminum particles with a purity of 99.99% are selected as the evaporation target;

[0123] S2: Deposit metal; fix the substrate selected in step S1 above the evaporation source, and wait until the vacuum degree of the electron beam evaporation system is 1×10 -5Pa started film deposition with a fixed evaporation rate of 0.1 nm / s, an evaporation distance of 50 cm, an electron gun voltage of 10 kV, and a substrate temperature of 25 ° C. A 20 nm aluminum layer was slowly deposited on both surfaces of the substrate to obtain a substrate wrapped in an aluminum layer.

[0124] S3: Pretreatment of deposited metal: The aluminum-coated substrate obtained in step S2 is placed in a heat treatment furnace, evacuated to below 1 Pa, and then argon gas is introduced until the heat treatment furnace reaches atmospheric pressure. Vacuuming is then continued multiple times to ensure an oxygen-free environment in the heat treatment furnace, i.e., to achieve the purpose of purging the heat treatment furnace. The heating rate is set at 15°C / min, the holding temperature is 800°C, and the holding time is 60 minutes. Cooling is then performed to obtain a highly crystalline aluminum coating. The cooling method is furnace cooling.

[0125] S4: Multiple aluminum-wrapped substrates were stacked and placed in a graphite mold in a hot pressing furnace. The heating rate was set to 15°C / min, the hot pressing temperature was set to 1000°C, the holding time was set to 60 minutes, the pressing time and the heating time were carried out simultaneously, the hot pressing pressure was 50 MPa, and the holding time was 60 minutes. After cooling to room temperature with the furnace, samples were taken and the surface graphite was polished off. The Van der Pauw conductivity test was performed to obtain a copper sheet with a conductivity of 114.5% IACS and a size of 2 cm × 2 cm × 0.5 cm.

[0126] In summary, the process flow employed in this invention ensures the continuous distribution of heterogeneous atomic layers. Driven by differences in work functions, the charge of the interface components is redistributed, forming interface dipoles. This alters the material's band structure, creates new electron transition pathways, and constructs new conductive channels, improving the composite's electrical conductivity. Currently, composite materials prepared using this method have achieved electrical conductivity of 118.4% IACS. This means that while maintaining the same electrical conductivity, the weight and volume of the conductor can be reduced, facilitating lightweighting.

[0127] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be within the scope of protection of the present invention.

Claims

1. A method for controlling the interface of a graphene-copper composite material, characterized in that: The following steps are involved: S1: Raw material selection: select commercially available Gr / Cu / Gr foil as the substrate and high-purity metal particles as the evaporation target; S2: depositing metal; depositing heterogeneous metal layers of different thicknesses on both sides of the substrate using a vacuum thermal evaporation coating process to obtain the substrate wrapped by the heterogeneous metal layers; S3: Pretreatment of deposited metal: performing thermal annealing on the substrate obtained in step S2 to obtain a heterogeneous metal coating with high crystallinity; S4: stacking multiple substrates processed in step S3 to construct an interface structure conducive to electrical conductivity, and then performing a vacuum hot pressing process to prepare a highly conductive graphene copper block material; The thermal annealing treatment in step S3 is performed in a heat treatment furnace, and an argon atmosphere is maintained in the heat treatment furnace; for heterogeneous metals with a melting point higher than copper, the annealing temperature is controlled at 783-983°C; for heterogeneous metals with a melting point lower than copper, the annealing temperature is controlled at 883-983°C; and the annealing time is controlled at 30-150 minutes.

2. The method for controlling the interface of the graphene-copper composite material according to claim 1, wherein: The vacuum degree of the thermal evaporation coating process in step S2 is controlled to be ≤1×10 -5 Pa, and the evaporation rate was controlled at 0.1 nm / s.

3. A method for controlling the interface of a graphene-copper composite material, characterized in that: The following steps are involved: S1: Raw material selection: select commercially available Gr / Cu / Gr / foil as the substrate and high-purity metal particles as the evaporation target; S2: depositing metal; depositing heterogeneous metal layers of different thicknesses on both sides of the substrate using an electron beam evaporation coating process to obtain a substrate wrapped with the heterogeneous metal layers; S3: Pretreatment of deposited metal: performing thermal annealing on the substrate obtained in step S2 to obtain a heterogeneous metal coating with high crystallinity; S4: stacking multiple substrates processed in step S3 to construct an interface structure conducive to electrical conductivity, and then performing a vacuum hot pressing process to prepare a highly conductive graphene copper bulk material; The thermal annealing treatment in step S3 is performed in a heat treatment furnace, and an argon atmosphere is maintained in the heat treatment furnace; for heterogeneous metals with a melting point higher than copper, the annealing temperature is controlled at 783-983°C; for heterogeneous metals with a melting point lower than copper, the annealing temperature is controlled at 883-983°C; and the annealing time is controlled at 30-150 minutes.

4. The method for controlling the interface of the graphene-copper composite material according to claim 3, wherein: During the electron beam evaporation process in step S2, the vacuum degree is controlled at ≤1×10 -5 Pa, the fixed evaporation rate is 0.1 nm / s, the evaporation distance is 50 cm, the electron gun voltage is 10 KV, and the substrate temperature is 25 °C.

5. The method for controlling the interface of the graphene-copper composite material according to claim 2 or 4, wherein: In step S2, the thickness of the heterogeneous metal layer is controlled to be 20-100 nm.

6. The method for controlling the interface of the graphene-copper composite material according to claim 1 or 3, wherein: In the vacuum hot pressing process in step S4, the vacuum degree is controlled at 1×10 -4 Pa; the hot pressing pressure is controlled at 50MPa, the hot pressing temperature is controlled at 1000℃, the holding time is 60min, and the holding time is 60min.

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