Preparation method of TiB2 and graphene oxide synergistically reinforced copper-based composite material

Abstract

The application discloses a preparation method of a TiB2 and graphene oxide synergistically reinforced copper-based composite material, and specifically comprises the following steps: (1) powder pretreatment and suspension configuration; (2) high-temperature reduction; and (3) discharge plasma sintering. The application takes high-purity Cu powder as a matrix, takes nano TiB2 and GO as two-phase reinforcing phases, relies on high elastic modulus of TiB2 to bear friction load, and provides solid lubrication through GO two-dimensional sheet layers, cooperatively strengthens the copper-based composite material, and significantly improves the mechanical properties and wear resistance of the copper matrix. The application adopts a suspension pre-dispersion process, ethanol medium rapidly leads out the ball milling heat and isolates air, SDBS and PVP dispersants reduce the powder agglomeration trend, improve the mixing efficiency, cooperates with the tube furnace atmosphere reduction and the discharge plasma sintering process, utilizes the plasma activation to refine the matrix grains, and finally obtains the TiB2-GO / copper composite material which has high density, excellent comprehensive performance and a wider application range.

Description

Technical Field

[0001] This invention belongs to the field of copper-based composite material preparation technology, specifically relating to a method for preparing a copper-based composite material synergistically reinforced by TiB2 and graphene oxide. Background Technology

[0002] Copper and copper alloys are widely used in key components such as electrical contact elements and heat dissipation elements in the electronics, power, and aerospace industries due to their excellent electrical conductivity. However, pure copper has poor mechanical properties, low hardness, and insufficient tensile strength. It is prone to deformation and failure under high temperature and high load conditions, making it difficult to meet the requirements of high-end equipment for materials with both high mechanical and physical properties.

[0003] To improve the mechanical properties of copper-based materials, ceramic phase reinforcement is often used to prepare copper-based composites. TiB2, as a ceramic reinforcing phase, has high hardness, high elastic modulus, good thermal and electrical conductivity, and chemical stability. It also has good compatibility with the copper matrix, making it an ideal copper-based reinforcing phase. Graphene oxide (GO) has an ultra-high specific surface area and mechanical properties. It can form a two-dimensional barrier network in the copper matrix, effectively refining grains and hindering dislocation movement, thereby further improving the mechanical properties of the composite material.

[0004] Currently, the preparation of ceramic / graphene biphase reinforced copper-based composites faces several challenges: First, the reinforcing phase is prone to agglomeration, especially nanoscale TiB2 and two-dimensional GO sheets, which easily aggregate during mixing, leading to the failure of the reinforcing effect. Second, in wet dispersion, it is difficult to simultaneously utilize aqueous and alcoholic dispersion media, and a single dispersant cannot achieve uniform dispersion of the biphase reinforcing phase. Third, ball milling easily generates high temperatures, leading to copper powder oxidation and graphene sheet damage, and improper control of sintering process parameters can result in insufficient material density and grain growth, affecting the overall performance of the material. Therefore, it is urgent to develop a preparation method that utilizes two-dimensional carbon materials to regulate the distribution of ceramic particles, achieve uniform introduction of the TiB2 reinforcing phase, optimize the interfacial bonding state, and thus improve the overall performance of copper-based composites. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing a copper-based composite material synergistically reinforced by TiB2 and graphene oxide. By constructing a GO-SDBS two-dimensional dispersion system, the graphene oxide sheets serve as a spatial isolation carrier for TiB2 particles, achieving uniform anchoring and distribution of the ceramic reinforcing phase in the copper matrix. The combination of the two is beneficial to improving the microstructure and properties of the copper-based composite material, and the mechanical properties of the prepared TiB2-GO / copper composite material are significantly improved.

[0006] To achieve the above objectives, the present invention employs the following technical solution: A method for preparing a copper-based composite material synergistically reinforced with TiB2 and graphene oxide specifically includes the following steps: (1) Powder pretreatment and suspension preparation High-purity Cu powder and TiB2 powder were weighed separately and added to beakers in sequence. SDBS powder and graphene oxide (GO) powder were weighed separately. SDBS was added to the beaker first, followed by deionized water. The mixture was magnetically stirred until completely dissolved. Then, graphene oxide (GO) powder was added and ultrasonically treated to obtain a GO-SDBS suspension. The suspension was added to a beaker, followed by PVP dispersant. Anhydrous ethanol was added until the powder was completely submerged. The beaker was placed in a magnetic stirrer and stirred at room temperature. After thorough mixing, anhydrous ethanol was added again until the powder was submerged. The slurry was loaded into a ball mill jar, and cemented carbide balls were added. After assembly, the ball mill jar was fixed in a planetary ball mill for ball milling. (2) High-temperature reduction Take out the slurry after ball milling in step (1) and place it in a beaker. Place the beaker in a drying oven to dry it. Grind the dried powder evenly and spread it on a ceramic sintering boat. Then place it in a tube furnace. Set the program and carry out reduction treatment in a hydrogen atmosphere to finally obtain TiB2-GO / copper composite powder. (3) Spark plasma sintering The TiB2-GO / copper composite powder reduced in step (2) was ground and added to a graphite mold. The graphite mold was placed in the furnace cavity of the spark plasma sintering furnace for pre-compacting. After setting the program, the furnace cavity was vacuum treated and then sintered. After sintering, the furnace was cooled to obtain TiB2-GO biphase reinforced copper-based composite material.

[0007] Preferably, in step (1), the high-purity Cu powder is high-purity electrolytic Cu powder, in the form of grape bunches, with a purity of 99.9% and a particle size of 1-3 μm; TiB2 has a purity ≥99% and a particle size of 50-500 nm; graphene oxide (GO) is prepared by a modified Hummers method, with a sheet size of 1-10 μm, a peelability of 95%, a purity of 98%, and an oxygen content of approximately 42%; SDBS: sodium dodecylbenzenesulfonate; PVP: polyvinylpyrrolidone. SDBS, as an anionic surfactant, is used to improve the dispersion stability of GO sheets in the aqueous phase; PVP, as a polymeric protective agent, is used to reduce the agglomeration between TiB2 particles and improve the uniform distribution of ceramic particles in the copper powder; anhydrous ethanol, as a ball milling dispersion medium, is used to reduce the heat generated during ball milling and reduce copper powder oxidation.

[0008] Preferably, in step (1), the mass ratio of each raw material is as follows: based on the mass of copper powder, the amount of TiB2 reinforcing phase added is 0.5-5% of the mass of copper powder, the amount of graphene oxide (GO) added is 0.05-1% of the mass of copper powder, wherein the mass ratio of TiB2 to GO is preferably 10:1; the amount of SDBS added is 1-5 times the mass of graphene oxide, the amount of PVP added is 0.1-1% of the mass of copper powder; the amount of deionized water added is based on the ability to form a uniform and stable suspension of GO, preferably 20-30 mL.

[0009] Furthermore, in step (1), when the amount of TiB2 added is less than 0.5%, the amount of reinforcing phase is small, making it difficult to form an effective load transfer and grain strengthening effect; when the amount of TiB2 added exceeds 5%, due to the increase in the content of ceramic reinforcing phase, the tendency of particle collision and agglomeration is enhanced, which easily causes internal defects in the material and reduces the overall performance of the composite material. When the amount of GO added is less than 0.05%, it is difficult to give full play to the dispersion and regulation effect of the two-dimensional lamellar structure on TiB2 particles; when the amount of GO added exceeds 1%, GO lamellars are prone to stacking and agglomeration, affecting the continuity and conductivity of the copper matrix. Therefore, the preferred amount of TiB2 reinforcing phase is 1%-2% of the mass of copper powder, the preferred amount of GO is 0.1%-0.2%, the preferred amount of SDBS is twice the mass of GO, and the preferred amount of PVP is 0.2% of the mass of copper powder.

[0010] Preferably, in step (1), the magnetic stirrer is a DF-101S type heat-collecting magnetic stirrer, the stirring temperature is 25-30℃, the stirring time is set to 6-8h, and in addition to an appropriate amount of anhydrous ethanol (the amount added is sufficient to completely submerge the mixed powder and make the resulting slurry have good fluidity), polyvinylpyrrolidone is added as a dispersant in the beaker. The amount added depends on the dispersion of the mixed powder to promote more uniform dispersion of the powder.

[0011] Preferably, the planetary ball mill in step (1) is the Nanjing University Instruments QM-QX4 omnidirectional planetary ball mill, with a ball milling speed of 280-300 rpm, a ball-to-material ratio of 5:1, a ball milling time of 5 hours, and an intermittent (pause for 5 minutes after every 30 minutes of operation) ball milling mode. The ball tank and the ball milling media are both made of hard alloy.

[0012] Preferably, in step (2), the slurry after ball milling is taken out and placed in a beaker, and the residual slurry on the ball milling tank wall and the surface of the alloy balls is repeatedly rinsed with anhydrous ethanol. Then, it is placed in a drying oven to dry. The model of the drying oven is DHG-9000-9005, the drying temperature is 50-60℃, and the drying time is 12h.

[0013] Preferably, the tubular furnace in step (2) is model GSL-1200X, and the program is set as follows: the temperature is increased from room temperature to 600℃ at 10℃ / min, held for 2 hours, then decreased to 500℃ at 10℃ / min, and then cooled to room temperature with the furnace.

[0014] Preferably, the gas introduced in step (2) is 10% H2-90% Ar, and the introduction rate is 300-350 ml / min.

[0015] Preferably, in step (3), the inner diameter of the graphite mold is 20mm, the outer diameter is 60mm, and the height is 70mm. Carbon paper is used to separate the TiB2-GO / copper composite powder from the graphite mold to facilitate sampling and demolding after sintering.

[0016] Preferably, in step (3), the discharge plasma sintering furnace is a LaboxTM-300 model, and a thermocouple is used for temperature measurement. The front end of the thermocouple is inserted into the temperature measuring hole of the graphite mold.

[0017] Preferably, the discharge plasma sintering setting program in step (3) is as follows: the temperature is raised from room temperature to 550-600℃ and held for 5 minutes, then the temperature is raised to 850-900℃ and held for 5 minutes. The heating rate is 80-100℃ / min, the pre-pressure is 10MPa, the pressure is raised to 50MPa during the second heating process, and the temperature is held for 5 minutes before cooling with the furnace.

[0018] The innovation of this invention lies in: In terms of material design: This invention innovatively utilizes the two-dimensional sheet structure of graphene oxide as a carrier for regulating the dispersion of ceramic particles. Through the synergistic effect between GO and TiB2, the agglomeration of the reinforcing phase is reduced and the bonding quality of the reinforcing phase / copper matrix interface is improved. The synergistic effect of the two is beneficial to improving the comprehensive performance of copper-based composite materials.

[0019] Regarding the preparation method: This invention achieves pre-dispersion of graphene oxide by constructing a GO-SDBS aqueous suspension, and combines a process route of wet ball milling, drying, reduction, and spark plasma sintering to ensure that graphene oxide and TiB2 reinforcing phase are relatively uniformly dispersed in the copper matrix, thereby improving the microstructure and phase composition of the composite material and enhancing its overall performance. This method has a clear process flow, adjustable parameters, and certain process stability and potential for scale-up applications.

[0020] In terms of performance optimization: through the synergistic enhancement of TiB2 and GO and the optimization of process parameters, the resulting copper-based composite material can achieve good density, electrical conductivity and mechanical properties.

[0021] The beneficial effects of this invention are: This invention uses high-purity Cu powder as the matrix and nano-TiB2 and graphene oxide (GO) as biphase reinforcing phases. The high elastic modulus of TiB2 bears the frictional load, while the two-dimensional layers of GO provide solid lubrication, synergistically strengthening the copper-based composite material and significantly improving the mechanical and wear-resistant properties of the copper matrix. Traditional dry powder ball milling easily generates heat due to friction, and combined with the soft, easily ductile, and cold-welded characteristics of copper, this results in large-scale powder agglomeration and coarse composite particles. This invention employs a suspension pre-dispersion process, using ethanol as a medium to quickly remove heat from the ball milling and isolate it from air. SDBS and PVP dispersants reduce the tendency of powder agglomeration and improve mixing efficiency. Combined with a tube furnace atmosphere reduction and spark plasma sintering process, plasma activation refines the matrix grains, helping to improve the dispersion uniformity and interfacial bonding of the reinforcing phase in the copper matrix. Thus, the resulting composite material maintains high density and conductivity while simultaneously improving hardness and wear resistance. Ultimately, a TiB2-GO / copper composite material with high density, excellent comprehensive performance, and a wider range of applications is obtained. This method has a relatively clear process flow, adjustable parameters, and certain engineering application prospects. Attached Figure Description

[0022] Figure 1 A process flow diagram for the preparation of copper-based composite materials synergistically reinforced with titanium diboride and graphene oxide; Figure 2 The surface morphology of the Cu-1%TiB2-0.1%GO composite material is shown in the image. Figure 3 Surface morphology of Cu-2%TiB2-0.2%GO composite material; Figure 4 EDS analysis chromatogram of Cu-1%TiB2-0.1%GO composite material; Figure 5 EDS analysis chromatogram of Cu-2%TiB2-0.2%GO composite material. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0024] Example 1

[0025] The TiB2-GO / copper composite powder in this example was processed through suspension preparation, wet ball milling, drying, reduction, and spark plasma sintering. The copper powder had a purity of ≥99.9%, was grape-like in shape, and had a particle size of 1-3 μm; the TiB2 had a purity of ≥99% and a particle size of 50-500 nm; the graphene oxide (GO) was prepared by a modified Hummers method, with a sheet size of 1-10 μm, a peelability of 95%, a purity of 98%, and an oxygen content of approximately 42%; SDBS: sodium dodecylbenzenesulfonate; and PVP: polyvinylpyrrolidone.

[0026] The preparation method of the TiB2-GO / copper composite material in this embodiment is as follows: (1) Powder pretreatment and suspension preparation 29.67 g of copper powder and 0.3 g of TiB2 powder were weighed and added to a beaker, along with 0.06 g of SDBS. 25 mL of deionized water was added, and the mixture was magnetically stirred for 10 min until completely dissolved, yielding an SDBS solution of 2.4 mg / mL. 0.03 g of GO was then weighed and added to the above solution. The mixture was then ultrasonically dispersed using an ultrasonic cleaner for 10 min, with the suspension temperature controlled below 25°C during the ultrasonication process, resulting in a uniformly dispersed GO-SDB solution of 1.2 mg / mL. S suspension: Pour 25 mL of the above GO-SDBS suspension into a beaker, add 0.06 g PVP, and add anhydrous ethanol until the powder is completely submerged. Place the beaker in a magnetic stirrer and stir at 25-30°C for 6-8 hours. After stirring thoroughly, add anhydrous ethanol again until the powder is submerged. Add carbide balls at a ball-to-powder ratio of 5:1. After assembly, fix the ball milling jar in a planetary ball mill and ball mill for 5 hours. The ball milling should be run in an intermittent manner (pause for 5 minutes after every 30 minutes of operation). (2) High-temperature reduction The slurry after ball milling was taken out and placed in a beaker. The remaining slurry on the surface of the ball milling jar and alloy balls was repeatedly rinsed with anhydrous ethanol. The beaker was then placed in a drying oven for drying at 50-60℃ for 12 hours. After drying, the obtained powder was ground and evenly spread on a ceramic sintering boat and placed in a tube furnace. A reducing atmosphere was created by passing 10% H2-90% Ar gas through the furnace at a flow rate of 300-350 ml / min. The temperature was set to rise from room temperature to 600℃ at 10℃ / min, held for 2 hours, and then dropped to 500℃ at 10℃ / min. The furnace was then cooled to room temperature to obtain TiB2-GO / copper composite powder. (3) Spark plasma sintering The reduced TiB2-GO / copper composite powder was ground and added to a graphite mold (with an inner diameter of 20 mm, an outer diameter of 60 mm, and a height of 70 mm, and the TiB2-GO / copper composite powder was separated from the graphite mold by carbon paper for easy sampling and demolding after sintering) wrapped in carbon paper. The graphite mold was then placed in the furnace cavity of a spark plasma sintering furnace and pre-compacted at a pressure of 10 MPa. The tip of a thermocouple was inserted into the temperature measuring hole of the graphite mold. The furnace door was closed for vacuum treatment. After the furnace cavity reached the vacuum level, sintering was carried out according to the set program as follows: the temperature was raised from room temperature to 550-600℃ and held for 5 min, then the temperature was raised to 850-900℃ and held for 5 min, with a heating rate of 80-100℃ / min. During this process, the pressure was raised to 50 MPa and held for 5 min. After cooling in the furnace, the TiB2-GO / copper composite material was obtained.

[0027] Example 2

[0028] The TiB2-GO / copper composite powder in this example was processed through suspension preparation, wet ball milling, drying, reduction, and spark plasma sintering. The copper powder had a purity of ≥99.9%, was grape-like in shape, and had a particle size of 1-3 μm; the TiB2 had a purity of ≥99% and a particle size of 50-500 nm; the graphene oxide (GO) was prepared by a modified Hummers method, with a sheet size of 1-10 μm, a peelability of 95%, a purity of 98%, and an oxygen content of approximately 42%; SDBS: sodium dodecylbenzenesulfonate; and PVP: polyvinylpyrrolidone.

[0029] The preparation method of the TiB2-GO / copper composite material in this embodiment is as follows: Powder pretreatment and suspension preparation 29.34 g of copper powder and 0.6 g of TiB2 powder were weighed and added to a beaker, along with 0.12 g of SDBS. 25 mL of deionized water was added, and the mixture was magnetically stirred for 15 min until completely dissolved, yielding an SDBS solution of 4.8 mg / mL. 0.06 g of GO was then weighed and added to the above solution. The mixture was then ultrasonically dispersed using an ultrasonic cleaner for 15 min, with the suspension temperature controlled below 25°C during the ultrasonication process, resulting in a uniformly dispersed GO-SDB solution of 2.4 mg / mL. S suspension: Pour 25 mL of the above GO-SDBS suspension into a beaker, add 0.06 g PVP, and add anhydrous ethanol until the powder is completely submerged. Place the beaker in a magnetic stirrer and stir at 25-30°C for 6-8 hours. After stirring thoroughly, add anhydrous ethanol again until the powder is submerged. Add carbide balls at a ball-to-powder ratio of 5:1. After assembly, fix the ball milling jar in a planetary ball mill and ball mill for 5 hours. The ball milling should be run in an intermittent manner (pause for 5 minutes after every 30 minutes of operation). (2) High-temperature reduction The slurry after ball milling was taken out and placed in a beaker. The remaining slurry on the surface of the ball milling jar and alloy balls was repeatedly rinsed with anhydrous ethanol. The beaker was then placed in a drying oven for drying at 50-60℃ for 12 hours. After drying, the obtained powder was ground and evenly spread on a ceramic sintering boat and placed in a tube furnace. A reducing atmosphere was created by passing 10% H2-90% Ar gas through the furnace at a flow rate of 300-350 ml / min. The temperature was set to rise from room temperature to 600℃ at 10℃ / min, held for 2 hours, and then dropped to 500℃ at 10℃ / min. The furnace was then cooled to room temperature to obtain TiB2-GO / copper composite powder. (3) Spark plasma sintering The reduced TiB2-GO / copper composite powder was ground and added to a graphite mold (with an inner diameter of 20 mm, an outer diameter of 60 mm, and a height of 70 mm, and the TiB2-GO / copper composite powder was separated from the graphite mold by carbon paper for easy sampling and demolding after sintering) wrapped in carbon paper. The graphite mold was then placed in the furnace cavity of a spark plasma sintering furnace and pre-compacted at a pressure of 10 MPa. The tip of a thermocouple was inserted into the temperature measuring hole of the graphite mold. The furnace door was closed for vacuum treatment. After the furnace cavity reached the vacuum level, sintering was carried out according to the set program as follows: the temperature was raised from room temperature to 550-600℃ and held for 5 min, then the temperature was raised to 850-900℃ and held for 5 min, with a heating rate of 80-100℃ / min. During this process, the pressure was raised to 50 MPa and held for 5 min. After cooling in the furnace, the TiB2-GO / copper composite material was obtained.

[0030] Table 1 below lists the mechanical properties of pure Cu and composite materials with different TiB2 / GO ratios. It should be noted that the contents of TiB2 and GO changed in both Example 1 and Example 2. Therefore, the results in the table are mainly used to illustrate the changes in the properties of composite materials under different biphase reinforcement ratios, as well as the applicability of the preparation process of this invention to different ratio systems, and not as a direct comparison basis for the influence of a single factor.

[0031] Table 1. Performance of the Sample Block

[0032] As shown in Table 1, compared with pure Cu, the addition of TiB2 and GO biphase reinforcing phases improved the hardness and wear resistance of the composite material. The Cu-1%TiB2-0.1%GO sample exhibited superior overall performance, with a hardness of 132.4 HV and a friction coefficient reduced to 0.47, indicating that the synergistic effect of appropriate amounts of TiB2 and GO is beneficial to enhancing material properties. When the reinforcing phase content was further increased to Cu-2%TiB2-0.2%GO, the increased agglomeration tendency due to the increased reinforcing phase content reduced the overall performance improvement.

[0033] from Figure 2 , Figure 3 It can be seen that for the Cu-1%TiB2-0.1%GO sample, the matrix structure is dense, and regular parallel polishing scratches are visible on the polished surface. A small amount of second-phase particles are uniformly dispersed in the copper matrix, and no obvious filler agglomeration, pores, or microcracks are observed. The observation that the second-phase particles are dispersed in the copper matrix indicates that the wet dispersion and ball milling processes are beneficial to improving the agglomeration behavior of the reinforcing phase. When the content of the reinforcing phase is increased to Cu-2%TiB2-0.2%GO, the amount of the second phase increases significantly, and larger agglomerates are formed in some areas. This is because after the total amount of reinforcing phase is increased, the total specific surface area of ​​TiB2 and GO increases, the mutual attraction between particles is enhanced, and the graphene oxide sheets are prone to overlap and stacking, which in turn induces filler agglomeration. Filler agglomeration is prone to form stress concentration points inside the material, which is not conducive to improving mechanical and tribological properties. The comprehensive morphology results show that the addition ratio of 1%TiB2-0.1%GO is more conducive to achieving uniform dispersion of the reinforcing phase in the copper matrix.

[0034] from Figure 4 , Figure 5 As can be seen, various elemental additions can be found from the energy spectrum analysis.

[0035] This invention combines TiB2 hard particles with graphene oxide (GO), leveraging the high elastic modulus of TiB2 to bear frictional loads and the two-dimensional GO sheets to provide solid lubrication, synergistically strengthening the copper-based composite material and significantly improving the mechanical properties and wear resistance of the copper matrix. Traditional dry powder ball milling easily generates heat due to friction, and combined with the soft and easily ductile cold welding characteristics of copper, it causes large-scale powder agglomeration and coarse composite particles. This invention employs a suspension pre-dispersion process, using ethanol as a medium to quickly remove heat from the ball milling and isolate air, while SDBS and PVP dispersants reduce the tendency of powder agglomeration and improve mixing efficiency. Combined with a tube furnace atmosphere reduction and spark plasma sintering process, plasma activation is used to refine the matrix grains, ultimately producing a TiB2-GO / copper composite material with high density, excellent comprehensive performance, and a wider range of applications.

[0036] The above embodiments are merely illustrative of specific implementations of this disclosure, but the implementations of this disclosure are not limited to the above content. Any changes, modifications, substitutions, combinations, or simplifications made without substantially departing from the spirit and principle of the inventive concept of this disclosure shall be considered equivalent substitutions and included within the scope of protection defined by the claims.

Claims

1. A method for preparing a copper-based composite material synergistically reinforced with TiB2 and graphene oxide, characterized in that: Specifically, the following steps are included: (1) Powder pretreatment and suspension preparation High-purity Cu powder and TiB2 powder were weighed separately and added to beakers in sequence. SDBS powder and graphene oxide (GO) powder were weighed separately. SDBS was added to the beaker first, followed by deionized water. The mixture was magnetically stirred until completely dissolved. Then, graphene oxide (GO) powder was added and ultrasonically treated to obtain a GO-SDBS suspension. The suspension was added to a beaker, followed by PVP dispersant. Anhydrous ethanol was added until the powder was completely submerged. The beaker was placed in a magnetic stirrer and stirred at room temperature. After thorough mixing, anhydrous ethanol was added again until the powder was submerged. The slurry was loaded into a ball mill jar, and cemented carbide balls were added. After assembly, the ball mill jar was fixed in a planetary ball mill for ball milling. (2) High-temperature reduction Take out the slurry after ball milling in step (1) and place it in a beaker. Place the beaker in a drying oven to dry it. Grind the dried powder evenly and spread it on a ceramic sintering boat. Then place it in a tube furnace. Set the program and carry out reduction treatment in a hydrogen atmosphere to finally obtain TiB2-GO / copper composite powder. (3) Spark plasma sintering The TiB2-GO / copper composite powder reduced in step (2) was ground and added to a graphite mold. The graphite mold was placed in the furnace cavity of the spark plasma sintering furnace for pre-compacting. After setting the program, the furnace cavity was vacuum treated and then sintered. After sintering, the furnace was cooled to obtain TiB2-GO biphase reinforced copper-based composite material.

2. The preparation method of the TiB2 and graphene oxide synergistically reinforced copper-based composite material as described in claim 1, characterized in that: In step (1), the high-purity Cu powder is high-purity electrolytic Cu powder, which is grape-like, with a purity of 99.9% and a particle size of 1-3 μm; TiB2 has a purity of ≥99% and a particle size of 50-500 nm; graphene oxide (GO) is prepared by the modified Hummers method, with a sheet size of 1-10 μm, a peelability of 95%, a purity of 98%, and an oxygen content of about 42%; SDBS: sodium dodecylbenzenesulfonate, PVP: polyvinylpyrrolidone.

3. The preparation method of the TiB2 and graphene oxide synergistically reinforced copper-based composite material as described in claim 1, characterized in that: The mass ratio of each raw material in step (1) is as follows: based on the mass of copper powder, the amount of TiB2 reinforcing phase added is 0.5-5% of the mass of copper powder, the amount of graphene oxide (GO) added is 0.05-1% of the mass of copper powder, wherein the mass ratio of TiB2 to GO is preferably 10:1; the amount of SDBS added is 1-5 times the mass of graphene oxide, the amount of PVP added is 0.1-1% of the mass of copper powder; and the amount of deionized water added is 20-30 mL.

4. The preparation method of the TiB2 and graphene oxide synergistically reinforced copper-based composite material as described in claim 1, characterized in that: In step (1), the TiB2 reinforcing phase is 1%-2% of the copper powder mass, the graphene oxide (GO) addition is 0.1%-0.2% of the copper powder mass, the SDBS addition is twice the mass of the graphene oxide mass, and the PVP addition is 0.2% of the copper powder mass.

5. The preparation method of the TiB2 and graphene oxide synergistically reinforced copper-based composite material as described in claim 1, characterized in that: In step (1), the magnetic stirrer is a DF-101S type heat-collecting magnetic stirrer with a stirring temperature of 25-30℃ and a stirring time of 6-8h. In addition to an appropriate amount of anhydrous ethanol, polyvinylpyrrolidone is added to the beaker as a dispersant. The amount added depends on the dispersion of the mixed powder to promote more uniform powder dispersion. In step (1), the planetary ball mill is a Nanjing University Instruments QM-QX4 all-around planetary ball mill with a ball milling speed of 280-300rpm, a ball-to-material ratio of 5:1, a ball milling time of 5h, and an intermittent ball milling mode with a 5-minute pause after every 30 minutes of operation. The ball tank and the ball milling media are both made of hard alloy.

6. The preparation method of the TiB2 and graphene oxide synergistically reinforced copper-based composite material as described in claim 1, characterized in that: In step (2), the slurry after ball milling is taken out and placed in a beaker. The slurry residue on the ball milling tank wall and the surface of the alloy balls is repeatedly rinsed with anhydrous ethanol and then placed in a drying oven. The model of the drying oven is DHG-9000-9005, the drying temperature is 50-60℃, and the drying time is 12h.

7. The preparation method of the TiB2 and graphene oxide synergistically reinforced copper-based composite material as described in claim 1, characterized in that: In step (2), the tubular furnace is model GSL-1200X, and the program is set as follows: the temperature is increased from room temperature to 600℃ at 10℃ / min, held for 2 hours, and then decreased to 500℃ at 10℃ / min, and then cooled to room temperature with the furnace; the gas introduced in step (2) is 10% H2-90% Ar, and the introduction rate is 300-350 ml / min.

8. The preparation method of the TiB2 and graphene oxide synergistically reinforced copper-based composite material as described in claim 1, characterized in that: In step (3), the inner diameter of the graphite mold is 20mm, the outer diameter is 60mm, and the height is 70mm. Carbon paper is used to separate the TiB2-GO / copper composite powder from the graphite mold to facilitate sampling and demolding after sintering.

9. The preparation method of the TiB2 and graphene oxide synergistically reinforced copper-based composite material as described in claim 1, characterized in that: In step (3), the discharge plasma sintering furnace is model LaboxTM-300, and thermocouple temperature measurement is used. The front end of the thermocouple is inserted into the temperature measuring hole of the graphite mold.

10. The method for preparing a TiB2 and graphene oxide synergistically reinforced copper-based composite material as described in claim 1, characterized in that: The discharge plasma sintering program in step (3) is as follows: the temperature is raised from room temperature to 550-600℃ and held for 5 minutes, then the temperature is raised to 850-900℃ and held for 5 minutes. The heating rate is 80-100℃ / min, the pre-pressure is 10MPa, and the pressure is raised to 50MPa during the second heating process. After holding for 5 minutes, the temperature is cooled with the furnace.

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