High-strength wear-resistant copper-based composite material and preparation method thereof

Abstract

The invention discloses a high-strength wear-resistant copper-based composite material and a preparation method thereof. The composite material is composed of a copper matrix, reduced graphene oxide and a nano titanium carbide reinforced phase, wherein the reduced graphene oxide and the nano titanium carbide reinforced phase are uniformly dispersed in the copper matrix. The preparation method comprises the following steps: firstly, uniformly mixing the copper powder, the reduced graphene oxide and the nano titanium powder in a ball milling manner; then putting the mixed powder into a vacuum hot-pressing sintering furnace, and densifying at high temperature and high pressure to obtain a sintered block; and finally, the sintered block is subjected to hot rolling deformation and annealing treatment, and the final copper-based composite material is obtained. The preparation method is characterized in that nano titanium is introduced to serve as an interface modifier and can effectively improve the interface bonding property between copper and graphene, meanwhile, authigenic nano titanium carbide plays a dispersion strengthening role, and the authigenic nano titanium carbide and the strengthening and toughening effect of graphene cooperate to jointly strengthen a copper matrix. And through the process combination of hot pressing sintering and hot rolling annealing, the wear resistance of the material is remarkably improved while the high strength of the material is ensured.

Description

Technical Field

[0001] This invention relates to the field of powder metallurgy of metallic materials, and particularly to a high-strength, high-wear-resistant copper-based composite material reinforced by graphene and nano-titanium carbide, and its preparation method. Background Technology

[0002] Copper and its alloys are widely used in electronics, rail transportation, and aerospace due to their excellent electrical and thermal conductivity. However, pure copper suffers from low strength, insufficient hardness, poor wear resistance, and weak resistance to high-temperature softening, which severely restricts its application in harsh environments such as high temperature, high load, or high friction. To overcome these defects, researchers have prepared copper-based composites by introducing reinforcing phases into the copper matrix, aiming to synergistically improve its strength, wear resistance, and electrical conductivity. Carbon materials (such as graphite, carbon nanotubes, and graphene) are considered ideal reinforcing agents due to their excellent mechanical properties and self-lubricating characteristics. Graphene, in particular, as a two-dimensional nanomaterial, possesses theoretically extremely high strength and electrical conductivity and is considered the most promising reinforcing phase. However, translating the theoretical properties of graphene into macroscopic composite materials still faces challenges such as poor wettability between copper and carbon leading to weak interfacial bonding, easy agglomeration, wrinkling, and structural damage of graphene during preparation, and the fact that graphene / copper composites prepared by traditional powder metallurgy methods often result in a significant decrease in electrical and thermal conductivity while improving strength. Furthermore, existing composite processes mostly focus on powder composites and conventional sintering, resulting in low density and uneven distribution of the reinforcing phase in the prepared blanks. This leads to a significant decrease in the material's plasticity and toughness, and a poor synergistic improvement in strength and conductivity. Therefore, there is an urgent need to develop a new preparation method that balances the high dispersibility, strong interfacial bonding, and efficient densification of graphene. This method should achieve a synergistic improvement in the strength, conductivity, and thermal conductivity of copper-based composite materials through multi-scale structural control, in order to meet the application requirements of high-end electronic packaging, high-strength conductive components, and other fields. Summary of the Invention

[0003] The purpose of this invention is to provide a high-strength, wear-resistant copper-based composite material and its preparation method that is relatively simple to process, highly controllable, and easy to prepare on a large scale.

[0004] Another object of the present invention is to provide a high-strength, wear-resistant copper-based composite material. This composite material consists of a copper matrix and a reinforcing phase uniformly dispersed within the copper matrix. The reinforcing phase includes rGO and in-situ generated nano-titanium carbide particles, with the nano-titanium carbide particles specifically distributed at the interface between the copper matrix and rGO, and within the grains of the copper matrix.

[0005] The technical problem solved by this invention is achieved by the following technical solution: This invention proposes a method for preparing a high-strength, wear-resistant copper-based composite material, comprising: uniformly mixing copper (Cu) powder, nano-titanium (Ti) powder, GO dispersion and hydrazine hydrate in an appropriate amount of alcohol to obtain Cu-Ti-rGO composite powder; subsequently preparing a dense ingot by hot pressing sintering (900-950℃, 35-45Mpa, 2-3h); then hot rolling deformation of the ingot at 700-800℃, with a deformation amount of 60-70%; finally, annealing in a vacuum environment at 300-400℃ for 1.5-2.5 hours and cooling to room temperature.

[0006] This invention proposes a high-strength, wear-resistant copper-based composite material, which is prepared by the above-described method.

[0007] The beneficial effects of the preparation method of the copper-based composite material of this invention are as follows: By introducing 1-2 wt% Ti element and utilizing it to activate the interfacial reaction between the copper matrix and rGO, the bonding force between rGO and the copper matrix is ​​significantly improved, solving the problem of graphene dispersion and interfacial bonding in the metal matrix. Simultaneously, the in-situ reduction of GO with hydrazine hydrate combined with ball milling in an alcohol medium to prepare composite powder effectively prevents graphene agglomeration and ensures uniform powder dispersion. The subsequent hot rolling deformation (700-800℃, 60-70% deformation) combined with annealing (300-400℃, 1.5-2.5 hours) synergistic effect effectively eliminates internal porosity, significantly refines the copper matrix grains, and induces preferential orientation of rGO along the rolling direction, thereby maximizing its reinforcing effect. In the prepared Cu-Ti-rGO composite material, Ti element effectively activates the interfacial reaction, significantly enhancing the bonding force between rGO and the copper matrix. Combined with hot rolling and annealing processes, porosity is effectively eliminated, grains are refined, and the orientation distribution of rGO is controlled. These synergistic effects significantly improve the overall performance of the material, giving it high hardness, high strength, and excellent wear resistance, significantly outperforming traditional copper alloys and demonstrating broad application prospects. Attached Figure Description

[0008] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the embodiments will be briefly described below.

[0009] Figure 1 This is a microstructure diagram of the copper-based composite material prepared in Example 1 of the present invention; Figure 2 This is a microstructure diagram of the copper-based composite material prepared in Example 3 of the present invention; Figure 3 This is a microstructure diagram of the copper-based composite material prepared in Example 7 of the present invention. Detailed Implementation

[0010] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0011] In the description of this invention, it should be noted that the terms "first," "second," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0012] The preparation method of the copper-based composite material and the copper-based composite material of the present invention will be described in detail below.

[0013] This invention provides a method for preparing a high-strength, wear-resistant copper-based composite material, in parts by weight: S1, GO-Ti pre-dispersion and ball milling compound: GO aqueous suspension and nano-titanium powder were weighed according to the ratio of 0.1-0.3 wt% GO content and 1-2 wt% Ti content in the final composite material. An appropriate amount of anhydrous ethanol was added as a process control agent, and the mixture was mixed evenly to obtain a GO-Ti mixed slurry. The slurry was then placed in a ball mill for the first stage of ball milling. The ball milling process parameters were controlled as follows: ball-to-powder ratio (8:1)-(10:1), rotation speed 200-400 rpm, and ball milling time 8-12 hours. This stage aims to use mechanical ball milling to achieve full deagglomeration, dispersion and preliminary composite of GO sheets and nano-titanium powder, laying the foundation for the subsequent uniform composite structure. Extensive experiments have demonstrated that using the aforementioned ratios of nano-titanium content (1-2 wt%) and GO content (0.1-0.3 wt%) effectively achieves the synergistic effect of titanium's interfacial activation and rGO reinforcement, significantly improving the interfacial bonding strength and overall mechanical properties of the composite material. If the nano-titanium content is below 1 wt%, it is difficult to fully activate the interfacial reaction between the copper matrix and rGO, resulting in insufficient interfacial bonding and the inability to fully realize the reinforcing effect of rGO. If the nano-titanium content is above 2 wt%, excessive brittle titanium compounds or copper-titanium intermetallic compounds may form, increasing costs and impairing the material's plasticity and conductivity. Similarly, when the rGO content is below 0.1 wt%, its reinforcing effect is weak; above 0.3 wt%, agglomeration is highly likely, worsening dispersion uniformity and potentially forming defects, thus reducing material performance.

[0014] This invention employs a wet mixing process (alcohol medium) combined with a GO dispersion, rather than simple dry mixing or direct addition of graphene or rGO, because a liquid medium is more conducive to the uniform dispersion of GO sheets and prevents agglomeration. The subsequent hydrazine hydrate reduction step can directly reduce GO to rGO in situ within the mixed system, facilitating a tighter bond on the powder surface and laying the foundation for obtaining a uniform composite powder and excellent interfacial bonding. Direct addition of rGO or dry mixing methods cannot guarantee its effective dispersion and adhesion on the copper powder surface.

[0015] S2, In-situ reduction of GO combined with copper-based ball milling: Copper powder and hydrazine hydrate were added to the mixed slurry obtained in step S1, and a chemical reduction reaction was carried out under stirring conditions to reduce GO to rGO in situ. Then, the whole mixture was subjected to a second stage of ball milling with the same milling parameters as the first stage. This synergistic treatment further refined the powder, promoted the firm coating and uniform dispersion of rGO and Ti particles on the copper matrix surface, and strengthened the interfacial bonding. Finally, the ball-milled slurry was allowed to settle, the supernatant was removed, and it was dried to obtain Cu-Ti-rGO composite powder with uniform composition and good interfacial bonding.

[0016] More preferably, the volume ratio of the GO aqueous suspension to hydrazine hydrate is 50:1-3. Using the above ratio of hydrazine hydrate can completely reduce the GO in the GO aqueous suspension.

[0017] This patent employs a room-temperature air-drying process, drying a mixed slurry containing copper powder, nano-titanium powder, rGO, and hydrazine hydrate at room temperature under ventilated conditions. This allows moisture and hydrazine hydrate to gradually evaporate, avoiding high-temperature treatment and ensuring uniform coating and good dispersion of rGO and nano-titanium particles on the copper matrix surface. Heating for drying, besides posing safety risks, can easily cause oxidation of the nano-titanium powder surface, damaging the interfacial bonding quality of the composite powder. Furthermore, stirring during heating can lead to rGO re-agglomeration, making it difficult to achieve uniform distribution of the reinforcement, thus affecting the microstructure consistency and performance stability of the subsequent composite material. Therefore, this invention preferably achieves a stable air-drying process in the slurry under room-temperature conditions through continuous micro-air circulation, resulting in a Cu-Ti-rGO composite powder with uniform composition and good interfacial bonding.

[0018] S3. Hot pressing and sintering of the dried Cu-Ti-rGO composite powder; After drying, a uniformly mixed Cu-Ti-rGO composite powder is obtained, which is then sintered to allow graphene, nano-titanium powder and copper to react and generate a copper-based composite material.

[0019] More preferably, the Cu-Ti-rGO composite powder is placed in a graphite mold and then sintered in a hot-press sintering furnace. The graphite mold has good lubrication and wear resistance, facilitating the subsequent removal of the composite material from the mold. Sintering the Cu-Ti-rGO composite powder under pressure helps to lower the sintering temperature of copper powder, nano-titanium powder, and graphene to form the composite material. Simultaneously, it enables rapid and dense sintering of the powder, shortening the reaction time.

[0020] Preferably, sintering involves placing a graphite mold containing the composite powder into a hot-press sintering furnace and sintering under vacuum or an inert atmosphere (such as argon). An inert atmosphere or high vacuum environment is preferred as it effectively prevents oxidation of the nano-titanium powder and rGO at high temperatures, reduces harmful impurities and micropores in the composite material, and ensures a stable furnace environment. Subsequently, the composite powder is simultaneously heated and pressurized. Pressurization involves applying a furnace pressure of 35-45 MPa. This pressure range needs to be optimized and adjusted according to the mold size and powder loading; its core function is to effectively eliminate porosity between powder particles, which is a decisive factor in achieving near-theoretical high density in the billet. Heating involves raising the composite powder to 900-950℃. Then, it is held at the target temperature and selected pressure for 2-3 hours. Experimental verification shows that this temperature and time window is crucial: it ensures a strong metallurgical bond between copper powder particles through sufficient diffusion; simultaneously, it promotes the effective migration of titanium elements to the copper / rGO interface, reacting with rGO to form a strong and tough interfacial bond. It is important to emphasize that this upper temperature limit (950℃) effectively prevents excessive heat from causing excessive damage to the rGO structure or abnormal growth of copper matrix grains, thereby protecting the final performance of the material.

[0021] After sintering, the furnace temperature is extremely high, and the sample cannot be removed immediately. The composite ingot should be allowed to cool naturally to room temperature with the furnace to release internal stress and stabilize the microstructure. Only after cooling to room temperature can the mold be removed from the furnace to obtain a dense Cu-Ti-rGO composite ingot.

[0022] S4. Perform multiple hot rolling passes on the sintered Cu-Ti-rGO hot-pressed sintered billet; The sintered Cu-Ti-rGO hot-pressed ingot is placed in a rolling mill preheated to 700-800℃ for multi-pass hot rolling, with the cumulative deformation controlled at 60-70%. During hot rolling within this temperature range, the copper matrix is ​​in the dynamic recrystallization temperature range, significantly reducing deformation resistance and avoiding the risk of rolling cracks, while maintaining the high diffusion activity of titanium atoms, driving their migration and reaction at the rGO / copper interface. It is important to emphasize that the lower limit of 60% deformation can completely eliminate residual sintering porosity, while the upper limit of 70% can prevent excessive orientation of rGO lamellars, leading to anisotropy in properties. Experiments have verified that using 5-8 passes of stepped rolling with a 30-second holding time between passes can effectively suppress edge crack defects; if the temperature is below 700℃ or the deformation is less than 60%, the rolling force will surge and the tensile strength will decrease.

[0023] S5. Vacuum annealing is performed on hot-rolled steel sheets to strengthen them. Annealing is a key optimization step in this invention. Holding the material in a vacuum environment at 300-400℃ for 1.5-2.5 hours can efficiently eliminate the work hardening stress generated by hot rolling, regulate the dislocation density and complete the recovery process, while simultaneously promoting the directional migration of titanium elements to the rGO / copper interface to form a fine, continuous nano-titanium carbide reinforcing phase, thus stabilizing the final interface structure of the composite material.

[0024] Extensive experiments have demonstrated that annealing within this temperature and time range yields uniform and fine copper matrix grains and a nanoscale TiC interfacial gradient layer, achieving optimal synergy between matrix toughening and interfacial strengthening. This results in a copper-based composite material with high strength, high plasticity, and excellent electrical conductivity. If the annealing temperature is below 300℃ or the time is less than 1.5 hours, the residual stress relief rate is less than 60%, and the migration of titanium atoms at the interface is insufficient, leading to discontinuity in the TiC layer and a decrease in interfacial shear strength of over 30%. If the annealing temperature is above 400℃ or the time is longer than 2.5 hours, abnormal growth of copper grains occurs, the TiC phase coarsens and agglomerates, and thermal damage to the rGO structure intensifies, ultimately leading to a decrease in material strength and a deterioration in electrical conductivity.

[0025] It should be noted that the mixing, cold pressing, sintering, hot rolling and annealing mentioned in the embodiments of the present invention all adopt conventional equipment and process parameters in the field of metal material processing. For example, cold pressing is carried out on a hydraulic press, sintering is carried out in a tube furnace or vacuum sintering furnace, hot rolling is carried out on a reversible rolling mill, and annealing is carried out in a box furnace.

[0026] This invention also provides a high-strength, wear-resistant copper-based composite material. Ti element effectively activates the interfacial reaction, significantly enhancing the bonding force between rGO and the copper matrix. Combined with hot rolling and annealing processes, porosity is effectively eliminated, grains are refined, and the orientation distribution of rGO is controlled. These synergistic effects significantly improve the overall performance of the material, giving it high hardness, high strength, and excellent wear resistance, significantly outperforming traditional copper alloys and possessing broad application prospects. The features and performance of this invention are further described in detail below with reference to embodiments. Example

[0027] This embodiment provides a high-strength, wear-resistant copper-based composite material, composed of copper powder, nano-titanium powder, and rGO, wherein the nano-titanium content is 1.0 wt% and the rGO content is 0.1 wt%. The copper-based composite material provided in this embodiment weighs 60g.

[0028] This embodiment also provides a method for preparing copper-based composite materials: 0.6 g of nano-titanium powder was added to a GO-based aqueous suspension containing 0.06 g of GO, and ball-milled at 300 r / min for 4 hours to fully anchor the nano-Ti particles onto the GO sheets, obtaining a GO-Ti composite dispersion system. Then, 59.34 g of copper powder was added to the system, and the mixture was stirred electrically for 0.5 hours for initial mixing. Subsequently, 0.5 mL of hydrazine hydrate solution was added dropwise while stirring to reduce GO to rGO. The mixture was then ball-milled again at 300 r / min for 4 hours to fully composite the Cu, Ti, and rGO phases, with a total ball-milling time of 8 hours. After ball milling, the mixture was allowed to stand for 24 hours and then air-dried at room temperature to obtain Cu-Ti-rGO composite powder. This composite powder was placed in a graphite mold and placed in a vacuum hot press furnace under a pressure of 35 MPa, heated to 950℃ at 20℃ / min and held for 2 hours. After furnace cooling, a dense ingot was obtained. Finally, the billet is hot-rolled at 750°C (65% deformation), then vacuum annealed at 350°C for 2.5 hours and cooled to room temperature.

[0029] The scanning electron microstructure of the composite material is as follows: Figure 1 As shown, rGO and nano-titanium are uniformly dispersed within the copper matrix. The material exhibits the following properties: Vickers hardness of 118.4 HV, tensile strength of 870 MPa, and 0.2% yield strength of 750 MPa. Under the same test conditions, using silicon nitride spheres as the friction mating surface, the material exhibits a coefficient of friction of 1.18 and a wear rate of 4.7 × 10⁻⁶ under a 15 N load. -5 mm 3 / N / m, compared to pure copper (coefficient of friction 1.35, wear rate 8.2×10 -5 mm 3 (N / m) exhibits superior wear resistance. Example

[0030] This embodiment provides a high-strength, wear-resistant copper-based composite material, wherein the content of nano-titanium is 1.2 wt% and the content of rGO is 0.15 wt%. The copper-based composite material provided in this embodiment is 60 g.

[0031] The preparation method of the copper-based composite material provided in this embodiment is basically the same as the preparation method provided in Example 1, except that the proportion of reaction raw materials and the operating conditions are different.

[0032] In this embodiment, 59.19 g of copper powder, 0.72 g of nano-titanium powder, and a GO aqueous suspension containing 0.09 g of GO were used. The volume of hydrazine hydrate solution was 0.6 mL. The ball milling speed was 400 r / min, the hot pressing sintering pressure was 40 MPa, and the heating rate was 15℃ / min. The hot rolling temperature was 700℃ (60% deformation), and the annealing conditions were vacuum annealing at 300℃ for 2 hours.

[0033] The composite material in this embodiment has the following properties: Vickers hardness of 120.2 HV, tensile strength of 830 MPa, and 0.2% yield strength of 764 MPa. The material has a coefficient of friction of 1.14 under a 15 N load and a wear rate of 4.2 × 10⁻⁶. -5 mm 3 / N / m, significantly better than pure copper. Example

[0034] This embodiment provides a high-strength, wear-resistant copper-based composite material, wherein the content of nano-titanium is 1.5 wt% and the content of rGO is 0.20 wt%. The copper-based composite material provided in this embodiment weighs 60g.

[0035] The preparation method of the copper-based composite material provided in this embodiment is basically the same as the preparation method provided in Example 1, except that the proportion of reaction raw materials and the operating conditions are different.

[0036] In this embodiment, 58.98 g of copper powder, 0.90 g of nano-titanium powder, and 0.12 g of GO in an aqueous suspension were used. The amount of hydrazine hydrate solution used was 0.7 mL. The ball milling time was 10 h, and the hot pressing holding time was 2.5 h. The hot rolling temperature was 780 ℃ (70% deformation), and the annealing conditions were 400 ℃ vacuum annealing for 2 hours.

[0037] The microstructure of this copper-based composite material obtained using scanning electron microscopy is shown below. Figure 2rGO and nano-titanium are uniformly distributed in the copper matrix. The properties of the composite material in this embodiment are as follows: Vickers hardness of 116.3 HV, tensile strength of 846 MPa, 0.2% yield strength of 749 MPa, coefficient of friction of 1.19 under 15N load, and wear rate of 4.8 × 10⁻⁶. -5 mm 3 / N / m, which has significantly improved tribological properties compared to pure copper. Example

[0038] This embodiment provides a high-strength, wear-resistant copper-based composite material, wherein the content of nano-titanium is 1.8 wt% and the content of rGO is 0.25 wt%. The copper-based composite material provided in this embodiment weighs 60g.

[0039] The preparation method of the copper-based composite material provided in this embodiment is basically the same as the preparation method provided in Example 1, except that the proportion of reaction raw materials and the operating conditions are different.

[0040] In this embodiment, 58.77 g of copper powder, 1.08 g of nano-titanium powder, and 0.15 g of GO in the GO aqueous suspension were used. The volume of hydrazine hydrate solution was 0.65 mL. The hot-pressing sintering pressure was 35 MPa, and the heating rate was 25 °C / min. The hot-rolling temperature was 800 °C (68% deformation), and the annealing conditions were 380 °C vacuum annealing for 2.2 hours.

[0041] The composite material in this embodiment exhibits the following properties: a Vickers hardness of 122.7 HV, a tensile strength of 804 MPa, and a 0.2% yield strength of 770 MPa. Under a load of 15 N, the material has a coefficient of friction of 1.15 and a wear rate of 4.3 × 10⁻⁶. -5 mm 3 / N / m, significantly improved wear resistance compared to pure copper. Example

[0042] This embodiment provides a high-strength, wear-resistant copper-based composite material, wherein the content of nano-titanium is 2.0 wt% and the content of rGO is 0.30 wt%. The copper-based composite material provided in this embodiment weighs 60g.

[0043] The preparation method of the copper-based composite material provided in this embodiment is basically the same as the preparation method provided in Example 1, except that the proportion of reaction raw materials and the operating conditions are different.

[0044] In this embodiment, 58.62g of copper powder, 1.20g of nano-titanium powder, and 0.18g of GO were used in the GO aqueous suspension. The ball milling speed was 350r / min. The hot rolling temperature was 730℃ (62% deformation), and the annealing conditions were vacuum annealing at 330℃ for 2.1 hours.

[0045] The composite material in this embodiment has the following properties: Vickers hardness of 119.8 HV, tensile strength of 819 MPa, and 0.2% yield strength of 755 MPa. Under a load of 15 N, the material has a coefficient of friction of 1.21 and a wear rate of 5.1 × 10⁻⁶. -5 mm 3 / N / m, significantly better than pure copper. Example

[0046] This embodiment provides a high-strength, wear-resistant copper-based composite material, wherein the content of nano-titanium is 1.0 wt% and the content of rGO is 0.30 wt%. The copper-based composite material provided in this embodiment weighs 60g.

[0047] The preparation method of the copper-based composite material provided in this embodiment is basically the same as the preparation method provided in Example 1, except that the proportion of reaction raw materials and the operating conditions are different.

[0048] In this embodiment, 59.22 g of copper powder, 0.60 g of nano-titanium powder, and 0.18 g of GO in an aqueous suspension were used. The amount of hydrazine hydrate solution used was 0.55 mL. The hot-pressing sintering temperature was 930℃, the hot-rolling temperature was 780℃ (66% deformation), and the annealing conditions were vacuum annealing at 360℃ for 2.3 hours.

[0049] The composite material in this embodiment has the following properties: Vickers hardness 116.8 HV, tensile strength 808 MPa, 0.2% yield strength 763 MPa, coefficient of friction under 15N load is 1.17, and wear rate is 4.6 × 10⁻⁶. -5 mm 3 / N / m, with significantly improved tribological properties compared to pure copper. Example

[0050] This embodiment provides a high-strength, wear-resistant copper-based composite material, wherein the content of nano-titanium is 2.0 wt% and the content of rGO is 0.10 wt%. The copper-based composite material provided in this embodiment weighs 60g.

[0051] The preparation method of the copper-based composite material provided in this embodiment is basically the same as the preparation method provided in Example 1, except that the proportion of reaction raw materials and the operating conditions are different.

[0052] In this embodiment, 58.74 g of copper powder, 1.20 g of nano-titanium powder, and 0.06 g of GO in the GO aqueous suspension were used. The ball milling time was 12 hours, and the hot pressing holding time was 2.5 hours. The hot rolling temperature was 710℃ (69% deformation), and the annealing conditions were 390℃ vacuum annealing for 1.8 hours.

[0053] The hot-rolled microstructure of the copper-based composite material is shown below. Figure 3 The rGO and nano-titanium in the copper matrix exhibited good dispersion. The composite material in this embodiment has the following properties: Vickers hardness 125.7 HV, tensile strength 850 MPa, and 0.2% yield strength 770 MPa. Under a 15 N load, the material has a coefficient of friction of 1.14 and a wear rate of 4.2 × 10⁻⁶. -5 mm 3 / N / m, significantly lower than pure copper, demonstrating excellent wear resistance.

[0054] Experimental Example Experimental Example 1: The composite material was prepared using the same preparation method and steps as in Example 1, except that the rGO content used was 0.50 wt%.

[0055] This experimental example failed to produce a qualified composite material. Obvious cracks appeared inside the billet after hot pressing and sintering, and edge fracture occurred during hot rolling. Microstructure showed severe agglomeration of rGO, leading to localized hardness fluctuations (109~140 HV) and a tensile strength of only 580 MPa, which did not meet the application requirements.

[0056] Experimental Example 2: The composite material was prepared using the same preparation method and steps as in Example 1, except that the content of nano-titanium powder used was 0.80 wt% (i.e., the amount of nano-titanium powder added to the composite powder was 0.48 g).

[0057] In this experimental example, no continuous reinforcing phase was formed in the composite material. Titanium existed in solid solution form, and insufficient nano-titanium carbide was generated. The material properties were significantly reduced: Vickers hardness was 108 HV, tensile strength was 462 MPa (only 53% of Example 1), and the coefficient of friction and wear rate were twice that of Example 1, making it unsuitable for use as a structural material.

[0058] Experimental Example 3: The composite material was prepared using the same preparation method and steps as in Example 1, except that the hot rolling deformation temperature was 900℃ (100℃ beyond the specified temperature range).

[0059] While this method can successfully prepare composite materials, their frictional properties are poor, severely impacting overall usability. During hot rolling, significant cracking occurs on the material surface due to unstable frictional behavior. Furthermore, the mechanical properties of the composite material are extremely unevenly distributed, with some areas exhibiting excessively low strength and hardness while others are excessively high, resulting in poor overall performance consistency and failing to meet the requirements of practical applications.

[0060] In summary, the copper-based composite material preparation method provided by this invention successfully prepares Cu-Ti-rGO composite powder by uniformly mixing copper powder, nano-titanium powder, and GO aqueous suspension in an alcohol medium, followed by hydrazine hydrate reduction and subsequent ball milling. Subsequent hot pressing sintering, hot rolling deformation, and vacuum annealing processes yield a densified copper-based composite material with optimized microstructure. This method utilizes the reaction of nano-titanium powder and GO under hydrazine hydrate and subsequent treatment to effectively avoid graphene agglomeration, ensuring the uniform dispersion of the reinforcement in the copper matrix and the interfacial bonding strength. Simultaneously, the optimized process chain ensures the consistency and stability of the overall microstructure of the composite material, resulting in uniform and reliable mechanical properties (such as hardness and compressive strength) in all parts of the material. By controlling the ratio of nano-titanium powder to GO and the process parameters, nano-titanium carbide reinforcing phases can be generated in situ within the matrix, significantly improving the hardness and compressive strength of the composite material. The entire preparation process is relatively simple to operate, cost-controllable, and has a reasonable cycle time, possessing good potential for industrial production. The resulting copper-based composite material exhibits uniformly dispersed reinforcement, dual-scale structural characteristics, good interfacial bonding, no obvious defects, excellent hardness and compressive strength, stable and controllable microstructure, and the content of reinforcement can be flexibly adjusted by changing the raw material ratio, making it a promising candidate for application.

[0061] The embodiments described above are some, but not all, embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A high-strength wear-resistant copper-based composite material, characterized in that, consist of a copper matrix and a reinforcing phase uniformly dispersed in the copper matrix; the reinforcing phase comprises rGO and in-situ generated nano titanium carbide particles; the nano titanium carbide particles are distributed at the interface of the copper matrix and the reduced graphene oxide and inside the copper matrix grains.

2. A high-strength wear-resistant copper-based composite material according to claim 1, characterized in that, The content of the rGO is 0.1-0.3 wt% and the content of the nano titanium is 1-2 wt% by volume fraction, and the balance is copper.

3. A method for producing the high-strength wear-resistant copper-based composite material as claimed in claim 1 or 2, characterized in that, The method comprises the following steps: S1, powder mixing: mechanically mixing copper powder, graphene oxide (GO) aqueous suspension and nano titanium powder by a ball mill to obtain a mixed powder with uniform composition; S2, hot-pressing sintering: loading the mixed powder into a graphite mold and placing it in a vacuum hot-pressing sintering furnace, applying axial pressure and heating to a sintering temperature for heat preservation and pressure preservation, so as to densify the mixed powder and obtain a sintered ingot; S3, hot rolling and annealing: heating and then hot rolling the sintered ingot, and then performing annealing treatment to obtain the high-strength wear-resistant copper-based composite material.

4. The method of claim 3, wherein, In step S1, the particle size of the nano titanium powder is 50-300 nm and the particle size of the copper powder is 10-25 μm; the ball milling process is as follows: ball-to-material ratio (8:1) to (10:1), rotation speed 200-400 rpm, ball milling time 8-12 hours, and process control agent is anhydrous ethanol.

5. The method of claim 3, wherein, In step S2, the sintering temperature is 900-950℃, the axial pressure is 35-45 MPa, and the heat preservation and pressure preservation time is 2-3 hours.

6. The method of claim 3, wherein, In step S2, during the sintering process, the nano titanium powder reacts with the rGO to generate nano titanium carbide particles in-situ.

7. The method of claim 3, wherein, In step S3, the opening rolling temperature of the hot rolling is 700-800℃, and the cumulative deformation is 60%-70%.

8. The method of claim 3, wherein, In step S3, the annealing temperature is 300-400℃, and the heat preservation time is 1.5-2.5 hours.

9. A high-strength wear-resistant copper-based composite material and a method for producing the same, characterized by comprising: The copper-based composite material is prepared by the method as claimed in any one of claims 1-8.

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