Reduced graphene oxide-aluminum oxide reinforced copper-based composite material and preparation method and application thereof

Abstract

The invention discloses a reduced graphene oxide-aluminum oxide reinforced copper-based composite material and a preparation method and application thereof, and belongs to the technical field of copper-based composite materials. The material comprises a copper matrix and a reinforcement phase, the reinforcement phase comprises an Al2O3 reinforcement phase and an rGO reinforcement phase, and the Al2O3 reinforcement phase and the rGO reinforcement phase are generated through in-situ reaction of Al and GO; the Al2O3 reinforced phase is in solid solution in the copper matrix, wraps the copper matrix and the rGO reinforced phase and exists between the copper matrix and the rGO reinforced phase, and the rGO reinforced phase is randomly and uniformly distributed in the copper matrix. An intermediate transition layer is introduced to an rGO / Cu interface through a synthesis reaction, so that the dispersity of the rGO and the improvement of interface combination of the rGO and a Cu matrix can be realized, the comprehensive performance of the composite material is further improved, the development of a low-dimensional material reinforced Cu-based composite material is promoted, and the agglomeration and interface problems of redox graphene are solved.

Description

Technical Field

[0001] This invention belongs to the field of copper-based composite material technology, specifically relating to a reduced graphene oxide-alumina reinforced copper-based composite material, its preparation method, and its application. Background Technology

[0002] Copper (Cu)-based composite materials are widely used in rail transportation, high-voltage electrical appliances, aerospace, and defense industries due to their excellent strength, electrical and thermal conductivity, wear resistance, and processability. In recent years, with the rapid development of equipment technology in various fields, product service conditions have become increasingly demanding, placing higher requirements on the performance and reliability of Cu-based materials. To meet the performance requirements of new high-end equipment, the development of Cu-based composite materials that combine high strength, high conductivity, and high wear resistance is urgently needed.

[0003] The addition / formation of a second phase is one of the effective technical pathways for obtaining high-performance Cu-based composite materials. Reduced graphene oxide (rGO) is considered an ideal reinforcing phase for constructing high-strength, high-conductivity copper-based composites due to its excellent electrical, thermal, and mechanical properties. However, in practical preparation and application, the difficulty in uniformly dispersing rGO in the copper matrix and its poor interfacial bonding with the metal severely restricts the full realization of the composite material's performance. Furthermore, the preparation process requires maintaining the reduced state of the rGO, leading to a significant gap between actual performance and theoretical expectations. Most graphene-copper-based composites cannot simultaneously improve both the mechanical and electrical properties of the copper-based composite material due to interfacial wettability issues.

[0004] In summary, existing rGO-reinforced Cu-based composite materials suffer from technical problems such as uneven dispersion of rGO in the copper matrix, poor interfacial bonding between rGO and the copper matrix, and difficulty in maintaining the stable reduced state of rGO during preparation. Consequently, the mechanical and electrical properties of the composite materials cannot be optimized in a coordinated manner. There is an urgent need to develop a preparation technology for rGO-reinforced Cu-based composite materials that can solve the above problems. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the present invention aims to provide a reduced graphene oxide-alumina reinforced copper-based composite material, its preparation method, and its application. By introducing an intermediate transition layer at the rGO / Cu interface through a synthesis reaction, the dispersibility of rGO and its interfacial bonding with the Cu matrix can be improved, thereby enhancing the overall performance of the composite material, promoting the development of low-dimensional material-reinforced Cu-based composite materials, and solving the aggregation and interfacial problems of reduced graphene oxide.

[0006] To achieve the above objectives, the present invention employs the following technical solution: On one hand, this invention provides a reduced graphene oxide-alumina reinforced copper-based composite material, comprising a copper matrix and a reinforcing phase. The reinforcing phase includes an Al2O3 reinforcing phase and an rGO reinforcing phase, which are generated through an in-situ reaction of Al and GO. This in-situ reaction ensures the reduced state structure of the graphene oxide and simultaneously generates the Al2O3 reinforcing phase. The Al2O3 reinforcing phase is dissolved into the copper matrix and exists on the surface of both the copper matrix and the reduced graphene oxide (the Al2O3 reinforcing phase encapsulates both the copper matrix and the rGO reinforcing phase and exists between them). Both the rGO and Al2O3 reinforcing phases are randomly and uniformly distributed within the copper matrix. The Al2O3 reinforcing phase acts as a solid solution within the copper matrix, resulting in solid solution strengthening and improved mechanical properties. The rGO, while maintaining electrical conductivity, also enhances mechanical properties.

[0007] In an optional embodiment, the mass percentage of the reduced graphene oxide reinforcing phase in the reduced graphene oxide-alumina reinforced copper matrix composite is 0.1% to 0.5%; and the mass percentage of the alumina reinforcing phase in the reduced graphene oxide-alumina reinforced copper matrix composite is 2.5% to 8.5%.

[0008] In an optional embodiment, the compressive strength of the reduced graphene oxide-alumina reinforced copper matrix composite material is 550.8~716.0 MPa.

[0009] In an optional embodiment, the strain of the reduced graphene oxide-alumina reinforced copper matrix composite is 25.0% to 32.2%.

[0010] In an optional embodiment, the reduced graphene oxide-alumina reinforced copper matrix composite has a conductivity of 66.3%~84.8% IACS.

[0011] In an optional embodiment, the microhardness of the reduced graphene oxide-alumina reinforced copper matrix composite material is 103.0~154.6 HV.

[0012] In an optional embodiment, the Young's modulus of the reduced graphene oxide-alumina reinforced copper matrix composite material is 340.8~414.6 GPa.

[0013] In another aspect, the present invention also provides a method for preparing the reduced graphene oxide-alumina reinforced copper-based composite material as described in the foregoing embodiments, comprising the following steps: After mixing GO powder and Al powder, a first step of high-energy ball milling is performed in an argon atmosphere to generate in-situ rGO and Al2O3 reinforcing phase mixed powder. Then, spherical copper powder and the reinforcing phase mixed powder are subjected to a second step of high-energy ball milling to obtain the final composite material powder. Finally, the obtained composite material powder is subjected to vacuum hot pressing sintering to obtain reduced graphene oxide-alumina reinforced copper-based composite material.

[0014] In an optional embodiment, the Al powder has a particle size of 1~2 μm, and the GO powder is a single-layer graphene oxide with a sheet diameter of 1~10 μm.

[0015] In an optional embodiment, the spherical copper powder has a particle size of 30-50 μm, a mesh size of 300 mesh, and a purity of 99.99%.

[0016] In an optional embodiment, both the copper powder after high-energy ball milling and the mixed powder of rGO and Al2O3 reinforced phase after high-energy ball milling are in flake form.

[0017] In an optional embodiment, the mass ratio of Al powder to GO powder is 1.5~4.5:0.3; the mass ratio of the mixed powder of copper matrix and the reinforcing phase is 97.4:2.6~91:9.

[0018] In an optional embodiment, Al powder and GO powder are first ball-milled in one step to obtain a mixed powder of rGO and Al2O3 reinforcing phases. The high-energy ball milling speed is 300~500 r / min and the high-energy ball milling time is 5~7 h. Then, spherical copper powder and the mixed powder of rGO and Al2O3 reinforcing phases are ball-milled in a second step. The high-energy ball milling speed is 300~500 r / min and the high-energy ball milling time is 5~7 h.

[0019] In an optional embodiment, sintering is carried out by vacuum hot pressing sintering; the sintering temperature is 800~900 ℃, the sintering holding time is 20~40 min, the sintering pressure is 20~40 MPa, and the heating rate during the sintering process is 80~90 ℃ / min.

[0020] In another aspect, the present invention provides a high-strength and high-conductivity component, the raw materials for which the high-strength and high-conductivity component is prepared include the reduced graphene oxide-alumina reinforced copper-based composite material of the aforementioned embodiments.

[0021] In optional embodiments, high-strength, high-conductivity components include rotor bars for new energy vehicle motors, integrated circuit lead frames, pantograph plates for high-speed trains, or conductive seals for aerospace engines.

[0022] Compared with the prior art, the present invention has the following beneficial effects: The reduced graphene oxide-alumina reinforced copper-based composite material provided by this invention uses copper as the matrix and employs a dual-reinforcing phase to strengthen the Cu matrix. Al₂O₃ and reduced graphene oxide (rGO) are generated in situ through a chemical reaction between Al and graphene oxide (GO), serving as the dual reinforcing phases. During the in-situ reaction, Al acts as a reducing agent for GO. Al effectively ensures that the graphene oxide maintains a reduced structure during the in-situ reaction and subsequent processes. During sintering, Al₂O₃ diffuses into both the copper matrix and the reduced graphene oxide. Some Al₂O₃ dissolves in the copper matrix, producing a solid solution strengthening effect and acting as a bridge at the interface between copper and rGO, thereby effectively improving the interfacial bonding state and promoting the uniform dispersion of rGO in the matrix. The alumina reinforcing phase primarily improves the mechanical properties of the material, while the reduced graphene oxide helps optimize its electrical conductivity and tribological properties. The synergistic effect of the two phases achieves a combined improvement in material strength and conductivity, making it suitable for components requiring high strength, high conductivity, and low friction performance. Compared to the single GO / Cu composite material, the modified rGO / Al2O3 / Cu composite material showed an increase in strength of approximately 53.8%, an increase in microhardness of approximately 170.5%, and an increase in electrical conductivity of approximately 82.1%.

[0023] Furthermore, the more Al powder used, the better the strength, hardness, and friction reduction properties of the composite material. However, if the proportion of alumina is too high, especially exceeding 8.5%, the conductivity of the composite material will decrease significantly.

[0024] In the preparation method of the reduced graphene oxide-alumina reinforced copper matrix composite provided by this invention, the energy for the reaction between Al powder and GO powder comes from the energy input of high-energy ball milling, thereby promoting the in-situ generation of Al2O3 and rGO. However, the participation of a large amount of copper powder reduces the contact between Al powder and GO powder, thus preventing the reaction. Therefore, this invention creatively performs a two-step ball milling process. First, Al powder and GO powder are ball milled to ensure sufficient contact and reaction. Then, spherical copper powder is added for a second ball milling process. During the in-situ reaction and subsequent processes, Al ensures that the graphene oxide maintains a reduced structure. Finally, the composite powder obtained from the two-step ball milling is sintered. Under high-temperature conditions, Al2O3 can diffuse into both the copper matrix and rGO simultaneously. The two-step ball milling ensures the uniform distribution of the Al2O3 and rGO reinforcing phases and the bridging effect of Al2O3, improving the bonding problem between Cu and rGO. The first-step ball milling generates Al2O3 and rGO in situ and ensures that Al2O3 encapsulates rGO, while the second-step ball milling ensures the dispersion of the reinforcing phase in the matrix. Furthermore, compared to the traditional reduction of rGO in a reducing atmosphere, the in-situ reaction process of this invention uses Al as a reducing agent for GO, thus eliminating the need for subsequent reduction treatment and saving time and effort. Therefore, the Al2O3 generated in this way can not only enter the copper matrix to form a solid solution and produce solid solution strengthening, but also adhere to the copper matrix and the rGO surface to improve the interfacial bonding performance between the two. The above preparation process has advantages such as simple process, fewer steps, short production cycle, and low cost. Attached Figure Description

[0025] Figure 1 The original powder SEM morphology and XRD or Raman spectroscopy results are shown in the examples. Figure 2 The changes in compressive strength of the composite materials in Examples 1-3 and Comparative Examples 1-2 are shown. Figure 3 The microhardness of the composite materials of Examples 1-3 and Comparative Examples 1-2; Figure 4 The electrical conductivity of the composite materials of Examples 1-3 and Comparative Examples 1-2; Figure 5 The material microstructure of Example 1; Figure 6 The material microstructure of Example 2; Figure 7 The material microstructure of Example 3; Figure 8 The microstructure of the material in Comparative Example 1; Figure 9 The microstructure of the material in Comparative Example 2 is shown. Detailed Implementation

[0026] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0027] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0028] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0029] In this article, unless otherwise specified, “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of,” for example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a.”

[0030] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0031] The following provides a detailed description of the reduced graphene oxide-alumina reinforced copper-based composite material, its preparation method, and its applications provided by this invention.

[0032] This invention proposes a reduced graphene oxide-alumina reinforced copper-based composite material. The material uses copper as the matrix and Al₂O₃ and rGO as the reinforcing phases. It employs a dual-reinforcing phase to strengthen the Cu matrix, with the reinforcing phases generated in situ through a chemical reaction between Al and GO. Both the rGO and Al₂O₃ reinforcing phases are uniformly dispersed within the copper matrix.

[0033] In the above-mentioned reduced graphene oxide-alumina reinforced copper matrix composite material, Al can effectively ensure that graphene oxide presents a reduced state structure in the in-situ reaction and subsequent processes. The part of Al2O3 generated in situ dissolves in the copper matrix to produce a solid solution strengthening effect and plays a bridging role in the interface region between copper and rGO, thereby effectively improving the interfacial bonding state between the two and promoting the uniform dispersion of rGO in the copper matrix.

[0034] Through the solid solution of Al2O3 in the copper matrix and the diffusion of Al2O3 in rGO, the Al2O3 reinforcement simultaneously coats both the copper matrix and the rGO reinforcement phase, which is beneficial for the uniform dispersion of rGO. Furthermore, the Al2O3 reinforcement phase distributed between the copper matrix and the rGO reinforcement phase helps to improve the poor bonding performance between the copper matrix and rGO. Through the solid solution strengthening of Al2O3 and the strong conductivity of rGO, the mechanical and electrical properties of the copper matrix composite material can be improved simultaneously. The reduced graphene oxide-alumina reinforced copper matrix composite material with the above characteristics has excellent mechanical and electrical properties.

[0035] In some embodiments, the mass fraction of the rGO reinforcing phase in the reduced graphene oxide-alumina reinforced copper matrix composite is 0.1% to 0.5%, such as 0.1%, 0.25%, or 0.5%, or other values ​​within the range of 0.1% to 0.5%.

[0036] In some embodiments, the mass fraction of the Al2O3 reinforcing phase in the reduced graphene oxide-alumina reinforced copper matrix composite is 2.5% to 8.5%, such as 2.5%, 5%, or 8.5%, or other values ​​within the range of 2.5% to 8.5%.

[0037] In some embodiments, the compressive strength of the reduced graphene oxide-alumina reinforced copper matrix composite is 550.8~716.0 MPa.

[0038] In some embodiments, the strain of the reduced graphene oxide-alumina reinforced copper matrix composite is 25.0% to 32.2%.

[0039] In some embodiments, the conductivity of the reduced graphene oxide-alumina reinforced copper matrix composite is 66.3%~84.8% IACS.

[0040] In some embodiments, the microhardness of the reduced graphene oxide-alumina reinforced copper matrix composite is 103.0~154.6 HV.

[0041] In some embodiments, the Young's modulus of the reduced graphene oxide-alumina reinforced copper matrix composite is 340.8~414.6 GPa.

[0042] As mentioned above, the reduced graphene oxide-alumina reinforced copper-based composite material provided by this invention has good yield strength, compressive strength, compressive strain, electrical conductivity, hardness and Young's modulus.

[0043] Accordingly, the present invention also provides a method for preparing the reduced graphene oxide-alumina reinforced copper-based composite material as described in the foregoing embodiments, comprising the following steps: After mixing GO powder and Al powder, the first step of high-energy ball milling is carried out in an argon atmosphere to generate in-situ rGO and Al2O3 reinforcing phase mixed powder. Then, the spherical copper powder and the reinforcing phase mixed powder are subjected to a second step of high-energy ball milling to obtain the final composite material powder. Finally, the obtained composite material powder is subjected to vacuum hot pressing sintering. In some implementations, Al powder and GO powder are first ball-milled in one step to obtain a mixed powder of rGO and Al2O3 reinforcing phases. The high-energy ball milling speed is 300~500 r / min and the high-energy ball milling time is 5~7 h. Then, spherical copper powder and the mixed powder of rGO and Al2O3 reinforcing phases are ball-milled in a second step. The high-energy ball milling speed is 300~500 r / min and the high-energy ball milling time is 5~7 h.

[0044] The copper powder after high-energy ball milling, the mixed powder of rGO and Al2O3 reinforcing phases after high-energy ball milling, and the final mixed powder are all in flake form.

[0045] The Al powder has a particle size of 1~2 μm, such as 1 μm, 1.2 μm, 1.4 μm, 1.6 μm, 1.8 μm, or 2 μm, or any other value within the range of 1~2 μm. The spherical copper powder has a particle size of 30~50 μm, a mesh size of 300 mesh, and a purity of 99.9%, such as 30 μm, 34 μm, 38 μm, 42 μm, 46 μm, or 50 μm, or any other value within the range of 30~50 μm. The GO powder is a single layer with a flake diameter of 1~10 μm, such as 1 μm, 2 μm, 4 μm, 6 μm, 8 μm, or 10 μm, or any other value within the range of 1~10 μm.

[0046] The mass ratio of Al powder to GO powder is 1.5 to 4.5:0.3, such as 1.5:0.3, 3:0.3, or 4.5:0.3. The mass ratio of the spherical copper powder mixed with the reinforcing phase of rGO and Al2O3 is 97.4:2.6 to 91:9, such as 97.4:2.6, 96.0:4.0, 94.2:5.8, 93.3:6.7, 91.9:8.1, or 91:9, or any other value within the range of 97.4:2.6 to 91:9.

[0047] In this invention, sintering is carried out using vacuum hot pressing sintering. This method has simple equipment, a short processing cycle, and the vacuum isolation of oxygen can prevent other oxidation processes, making it more cost-effective than other methods.

[0048] In some embodiments, the sintering temperature is 800~900 ℃. Too low a sintering temperature will result in incomplete sintering and insufficient alumina diffusion; too high a sintering temperature will easily lead to re-oxidation of rGO, impairing the conductivity of the composite material. The sintering holding time is 20~40 min, the sintering pressure is 20~40 MPa, and the heating rate during the sintering process is 80~90 ℃ / min.

[0049] Through the aforementioned sintering process, the interfacial bonding between the copper matrix and the rGO reinforcing phase was successfully improved by utilizing the diffusion of Al2O3, thus enhancing the interfacial bonding performance between the two phases. Specifically, during sintering, the Al2O3 reinforcing phase diffuses into both the copper matrix and the rGO reinforcing phase. The Al2O3 reinforcing phase adhering to the surfaces of the copper matrix and the rGO reinforcing phase effectively improves the interfacial bonding between them.

[0050] In addition, the present invention also provides a high-strength and high-conductivity component, the raw materials for which the high-strength and high-conductivity component is prepared include the above-mentioned reduced graphene oxide-alumina reinforced copper-based composite material.

[0051] For example, high-strength, high-conductivity components may include rotor bars for new energy vehicle motors, integrated circuit lead frames, pantograph plates for high-speed trains, or conductive seals for aerospace engines, as well as products requiring high strength, high conductivity, and / or friction reduction.

[0052] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0053] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.

[0054] Example 1 This embodiment provides a method for preparing a reduced graphene oxide-alumina reinforced copper-based composite material, including the following steps: Step 1: First, Al powder and GO powder are ball-milled in a mass ratio of 1.5:0.3 to obtain a mixed powder of rGO and Al2O3. The high-energy ball milling speed is 300 r / min and the high-energy ball milling time is 5 h.

[0055] Step 2: The spherical copper powder is then mixed with rGO and Al2O3 reinforcing phase powder at a mass ratio of 97.4:2.6 and ball-milled in a second step. The high-energy ball milling speed is 300 r / min and the high-energy ball milling time is 5 h to obtain the final mixed powder.

[0056] Step 3: After filling the obtained composite material powder into a graphite mold, vacuum hot pressing sintering is performed. The temperature is raised to 800 ℃ at a heating rate of 80 ℃ / min and held for 20 min. The pressure is set to 20 MPa. After the holding period, the furnace is cooled to obtain the reduced graphene oxide-alumina reinforced copper-based composite material.

[0057] Example 2 The difference between this embodiment and Embodiment 1 is that: in step one, the mass ratio of Al powder to GO powder is 3:0.3, the high-energy ball milling speed is 400 r / min, and the high-energy ball milling time is 6 h; In step two, the spherical copper powder was mixed with rGO and Al2O3 reinforcing phase powder at a mass ratio of 94.2:5.8, and the high-energy ball milling speed was 400 r / min for 6 h. In step three, the temperature is raised to 850 ℃ at a heating rate of 85 ℃ / min and held for 30 min, with the pressure set at 30 MPa.

[0058] Example 3 The difference between this embodiment and Embodiment 1 is that: in step one, the mass ratio of Al powder to GO powder is 4.5:0.3, the high-energy ball milling speed is 500 r / min, and the high-energy ball milling time is 7 h; In step two, the spherical copper powder is mixed with rGO and Al2O3 reinforcing phase powder at a mass ratio of 91:9, and the high-energy ball milling speed is 500 r / min, and the high-energy ball milling time is 7 h. In step three, the temperature is raised to 900 ℃ at a heating rate of 90 ℃ / min and held for 40 min, with the pressure set at 40 MPa.

[0059] Comparative Example 1 This comparative example provides a graphene oxide-based copper-based composite material, which differs from Example 1 in that Al powder was not added for ball milling, and the composite material was obtained by vacuum hot pressing sintering according to the conditions in step three of Example 1.

[0060] Comparative Example 2 This comparative example provides a reduced graphene oxide-alumina reinforced copper-based composite material, which differs from Example 1 in that: after adding Al powder and ball milling, the proportion of alumina generated is 10%, and the composite material is obtained by vacuum hot pressing sintering according to the conditions in step three of Example 1.

[0061] Test case The yield strength, compressive strength, and compressive strain of the materials obtained in Examples 1-3, Comparative Examples 1 and 2 were measured according to GB / T7314-2005; electrical conductivity according to GB / T32791-2016; microhardness according to GB / T4340.3-2012; and Young's modulus according to GB / T25898-2010. The test structures are shown in Table 1 and... Figures 2-4 As shown.

[0062] Table 1 Test Results

[0063] As shown in Table 1, the reduced graphene oxide-alumina reinforced copper-based composite material provided in this embodiment of the invention exhibits good compressive strength, strain, electrical conductivity, microhardness, and Young's modulus compared to a single reinforcing phase. With increasing Al powder content, the reduced graphene oxide did not show significant agglomeration, and the material's mechanical properties increased with increasing aluminum powder content; however, when excessive Al powder resulted in an alumina content exceeding 8.5%, the material's mechanical properties actually decreased.

[0064] like Figure 1 As shown in Figure (a), the aluminum powder contains no impurities and has a particle size of 1-2 μm; Figure (b) shows that the copper powder contains no impurities and has a particle size of 30-50 μm; Figure (c) shows that the GO powder contains no impurities and has a single-layer sheet diameter of 1-10 μm; and Figure (d) shows that after one-step ball milling, alumina successfully encapsulates reduced graphene oxide. Figures 5-7 As shown, the prepared reduced graphene oxide-alumina reinforced copper-based composite material has a uniform microstructure distribution and is free of microscopic cracks and pores. Figures 8-9 As shown, the prepared comparative sample exhibits obvious microscopic defects such as pores.

[0065] In summary, the reduced graphene oxide-alumina reinforced copper-based composite material prepared in this invention utilizes the in-situ chemical reaction of Al and GO to generate Al2O3 and rGO as dual reinforcing phases. The in-situ reaction of Al and GO ensures the reduced state structure of graphene oxide while simultaneously generating the Al2O3 reinforcing phase. During sintering, Al2O3 diffuses into both the copper matrix and the reduced graphene oxide, with some Al2O3 dissolving in the copper matrix to produce a solid solution strengthening effect. Al2O3 also acts as a bridge at the interface between copper and rGO, effectively improving the interfacial bonding and promoting the uniform dispersion of rGO in the matrix. The alumina reinforcing phase primarily improves the mechanical properties of the material, while the reduced graphene oxide reinforcing phase helps optimize its electrical conductivity. Their synergistic effect achieves a combined improvement in both strength and conductivity. The resulting reduced graphene oxide-alumina reinforced copper-based composite material exhibits excellent compressive strength and compressive strain, electrical conductivity, microhardness, and Young's modulus.

[0066] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of this invention.

Claims

1. A reduced graphene oxide-alumina reinforced copper-based composite material, characterized in that, It includes a copper matrix and a reinforcing phase, wherein the reinforcing phase includes an Al2O3 reinforcing phase and an rGO reinforcing phase, and the Al2O3 reinforcing phase and the rGO reinforcing phase are generated by an in-situ reaction of Al and GO; The Al2O3 reinforcing phase is dissolved in the copper matrix, encapsulates the copper matrix and the rGO reinforcing phase, and exists between the copper matrix and the rGO reinforcing phase. The rGO reinforcing phase is randomly and uniformly distributed in the copper matrix.

2. The reduced graphene oxide-alumina reinforced copper-based composite material according to claim 1, characterized in that, The mass percentage of the rGO reinforcing phase in the reduced graphene oxide-alumina reinforced copper matrix composite is 0.1% to 0.5%; the mass percentage of the Al2O3 reinforcing phase in the reduced graphene oxide-alumina reinforced copper matrix composite is 2.5% to 8.5%.

3. The reduced graphene oxide-alumina reinforced copper-based composite material according to claim 1, characterized in that, The reduced graphene oxide-alumina reinforced copper matrix composite material has a compressive strength of 550.8~716.0 MPa, a strain of 25.0%~32.2%, a conductivity of 66.3%~84.8% IACS, a microhardness of 103.0~154.6 HV, and a Young's modulus of 340.8~414.6 GPa.

4. A method for preparing a reduced graphene oxide-alumina reinforced copper-based composite material as described in any one of claims 1 to 3, characterized in that, Includes the following steps: After mixing GO powder and Al powder, a first step of high-energy ball milling is carried out in an argon atmosphere to generate in-situ rGO and Al2O3 reinforcing phase mixed powder. Then, spherical copper powder and the reinforcing phase mixed powder are subjected to a second step of high-energy ball milling to obtain composite material powder. Finally, the composite material powder is sintered to obtain reduced graphene oxide-alumina reinforced copper-based composite material.

5. The method for preparing the reduced graphene oxide-alumina reinforced copper-based composite material according to claim 4, characterized in that, The Al powder has a particle size of 1-2 μm, the GO powder is a single layer of graphene oxide with a sheet diameter of 1-10 μm; the spherical copper powder has a particle size of 30-50 μm, a mesh size of 300 mesh, and a purity of 99.99%; the mixed powder of rGO and Al2O3 as reinforcing phases is in the form of flakes, and the mixed powder of copper powder and reinforcing phases in the composite material powder is in the form of flakes.

6. The method for preparing the reduced graphene oxide-alumina reinforced copper-based composite material according to claim 4, characterized in that, The first step of high-energy ball milling involves a rotation speed of 300-500 r / min and a time of 5-7 h; the second step of high-energy ball milling involves a rotation speed of 300-500 r / min and a time of 5-7 h.

7. The method for preparing the reduced graphene oxide-alumina reinforced copper-based composite material according to claim 4, characterized in that, The mass ratio of Al powder to GO powder is 1.5~4.5:0.3; the mass ratio of spherical copper powder to the reinforcing phase mixed powder is 97.4:2.6~91:

9.

8. The method for preparing the reduced graphene oxide-alumina reinforced copper-based composite material according to claim 4, characterized in that, The sintering is carried out by vacuum hot pressing sintering; the sintering temperature is 800~900 ℃, the holding time is 20~40 min, the pressure is 20~40 MPa, and the heating rate of the sintering process is 80~90 ℃ / min.

9. A high-strength, high-conductivity component, characterized in that, The raw materials for preparing the high-strength and high-conductivity components include the reduced graphene oxide-alumina reinforced copper-based composite material as described in any one of claims 1 to 3.

10. The high-strength, high-conductivity component according to claim 9, characterized in that, The high-strength, high-conductivity components include rotor bars for new energy vehicle motors, integrated circuit lead frames, pantograph plates for high-speed trains, or conductive seals for aerospace engines.

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