Preparation method of low-dimensional carbonized polypyrrole synergistically reinforced copper-based composite material

Abstract

The invention relates to a preparation method of a low-dimensional carbonized polypyrrole matter synergistically reinforced copper-based composite material, carbonized polypyrrole nanotubes and carbonized polypyrrole balls are doped into a copper matrix through a route of combining molecular-level mixing and ball milling, and a new strategy for simultaneously introducing intracrystalline C-PNSs and grain boundary C-PNTs by regulating and controlling a microstructure is developed. According to the method, the dispersity and interface wettability of the C-PNTs are improved through molecular-level mixing, capturing and accumulation of dislocations in crystal grains are promoted through the C-PNSs distributed in the crystal grains, and therefore the strain hardening capacity is enhanced, and the C-PNTsamp is prepared; and the C-PNSs / Cu composite material realizes good strength and plasticity matching. Meanwhile, the copper-based composite material prepared through the method shows excellent mechanical property and conductivity, high-efficiency output is achieved with low cost, a new strategy and thought are provided for designing and preparing the high-performance copper-based composite material, and the research and development progress of materials in the field is promoted.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite materials, and in particular relates to a method for preparing a low-dimensional carbonized polypyrrole synergistically reinforced copper-based composite material. Background Art

[0002] Copper, with its excellent electrical and thermal conductivity and ductility, is widely used in power transmission cables, tram contact switches, brushes, integrated circuit leads, and other fields. Currently, the use of low-dimensional carbon nanomaterials (such as graphene and carbon nanotubes) as reinforcements to reinforce copper-based composites has been widely reported.

[0003] As a conductive polymer, polypyrrole (PP) possesses excellent electrical conductivity. Since its discovery, PP has attracted widespread attention in the field of nanomaterials due to its excellent mechanical and physicochemical properties. PP can be transformed into a carbon nanomaterial rich in carbon and nitrogen after high-temperature carbonization. These low-dimensional carbonized PPs have two typical morphologies: carbonized PP spheres (C-PNSs) and carbonized PP tubes (C-PNTs). Compared with graphene and carbon nanotubes, these low-dimensional carbonized PPs (C-PNTs and C-PNSs) offer simpler preparation processes, lower costs, greater practicality, and ease of large-scale production, making them suitable reinforcements for copper-based composites. For example, Li et al. achieved excellent mechanical properties by reinforcing copper-based composites with C-PNTs. However, significant challenges remain, such as strength-ductility mismatch and incompatibility with electrical conductivity. This "barrel effect" has hindered the widespread application of copper-based composites in engineering. There is a limit to the overall performance of composites that can be enhanced by using only C-PNTs. To further improve the overall performance, it is crucial to adjust the microstructure of metal-based composites from some new perspectives or adopt synergistic reinforcements. Therefore, using C-PNTs and C-PNSs as reinforcement phases for synergistic reinforcement is a promising method to achieve a good synergistic balance of strength, plasticity and conductivity in copper-based composites.

[0004] However, the current research on the relationship between the interface structure and performance of hybrid reinforcements is not in-depth enough, which hinders the research progress and application of low-dimensional carbonized polypyrrole synergistically reinforced copper-based composites. Summary of the Invention

[0005] Based on the above research background, the present invention proposes a preparation method for a low-dimensional carbonized polypyrrole synergistically reinforced copper-based composite material. The method first prepares polypyrrole nanotubes (PNTs) and polypyrrole nanospheres (PNSs) by chemical synthesis, and then obtains carbonized polypyrrole tubes (C-PNTs) and carbonized polypyrrole spheres (C-PNSs) as synergistic reinforcements by carbonization. C-PNTs & C-PNSs / Cu composite powders are obtained by molecular-level blending method (MLM) combined with segmented ball milling. The above powders are subjected to rapid hot pressing (FHP) to obtain C-PNTs & C-PNSs / Cu composite materials. On the one hand, this preparation method can improve the dispersibility and interfacial wettability of C-PNTs through molecular-level mixing. On the other hand, C-PNSs are distributed within the crystal by ball milling, which promotes the capture and accumulation of dislocations inside the grains, thereby enhancing the strain hardening ability. This simple and practical preparation process effectively addresses the challenges of prior art. The resulting C-PNTs and C-PNSs / Cu composite material achieves excellent strength-ductility balance and exhibits excellent electrical conductivity. Consequently, the present invention successfully develops a copper-based composite material with high overall performance.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A method for preparing a low-dimensional carbonized polypyrrole synergistically reinforced copper-based composite material, comprising the following steps:

[0008] (1) Preparation of carbonized polypyrrole nanotube (C-PNTs) reinforcement

[0009] FeCl3·6H2O powder was ultrasonically dispersed in deionized water and stirred for later use; methyl orange MO powder was ultrasonically dispersed in deionized water and stirred for later use; FeCl3·6H2O solution was slowly dripped into the methyl orange solution to mix, and then pyrrole was extracted with a pipette and slowly dripped into the mixed solution, followed by stirring, filtration and vacuum drying to obtain functional PNTs powder, which was then carbonized in a vacuum tube furnace to obtain C-PNTs powder;

[0010] Further optimization, the specific operation of step (1) is:

[0011] Weigh 1g~3g of FeCl3·6H2O (99%) brown-yellow powder into a 100ml beaker, then add 30ml of deionized water and ultrasonically disperse it for 10min~20min. After the ultrasonication is completed, place it on a magnetic stirrer and stir it for later use; weigh 0.1g~0.3g of methyl orange (MO, 99%) orange powder into a 500ml beaker, then add 100ml of deionized water and ultrasonically disperse it for 10min~20min. After the ultrasonication is completed, place it on a magnetic stirrer and stir it for later use; slowly drop the FeCl3·6H2O solution into the methyl orange solution to mix, then use a pipette to draw 420μL of pyrrole (98%) and slowly drop it into the mixed solution, and stir it at room temperature for 12~24h. Then, filter and vacuum dry to obtain functional PNTs powder, and finally carbonize it at 650℃~1000℃ in a vacuum tube furnace with inert gas to obtain C-PNTs powder.

[0012] (2) Preparation of carbonized polypyrrole nanospheres (C-PNSs) reinforcement

[0013] FeCl3·6H2O powder was ultrasonically dispersed in deionized water and stirred for later use. Subsequently, pyrrole was extracted with a pipette and slowly dripped into the FeCl3·6H2O solution. The mixture was stirred, filtered, and vacuum-dried to obtain functional PNSs powder. The powder was then carbonized in a vacuum tube furnace to obtain C-PNSs powder.

[0014] Further optimization, the specific operation of step (2) is:

[0015] Weigh 1g~3g of FeCl3·6H2O (99%) brown-yellow powder into a 500ml beaker, then add 100ml of deionized water and ultrasonically disperse for 10min~20min. After the ultrasonication is completed, place it on a magnetic stirrer and stir it for later use; then, use a pipette to extract 420μL of pyrrole (98%) and slowly drip it into the FeCl3·6H2O solution, and stir it at room temperature for 12~24h; then, obtain functional PNSs powder by filtration and vacuum drying; finally, introduce inert gas into a vacuum tube furnace and carbonize it at 650℃~1000℃ to obtain C-PNSs powder.

[0016] (3) Preparation of C-PNTs / Cu composite powder

[0017] The C-PNTs powder and CuAc·H2O prepared in step (1) are ultrasonically dispersed separately, and the C-PNTs dispersion solution is then added to the CuAc·H2O solution and stirred in a water bath to obtain a C-PNTs / CuAc mixed solution, followed by sequential addition of sodium hydroxide and glucose solution, stirring, filtering, drying, and reducing to obtain a C-PNTs / Cu composite powder;

[0018] Further optimization, the specific operation of step (3) is:

[0019] 0.3 g to 3 g of the carbonized polypyrrole tube (C-PNTs) powder prepared in step (1) and 15 g to 150 g of hydrated copper acetate (CuAc·H2O) were weighed and ultrasonically dispersed in deionized water for 10 min to 20 min, and then the C-PNTs dispersion solution was added to the CuAc·H2O solution, and stirred in a water bath at 60°C to 80°C for 30 min to 60 min to obtain a C-PNTs / CuAc mixed solution; subsequently, 9 g to 90 g of sodium hydroxide (0.5 mol / L) and 7 g to 70 g of glucose (0.8 mol / L) were weighed and dispersed into a solution and then added to the above mixed solution in sequence. When the color of the solution changed from dark blue to brick red, stirring was stopped, and C-PNTs / Cu2O powder was obtained by filtration and vacuum drying; finally, the above powder was placed in a vacuum tube furnace and reduced at a certain temperature for a period of time to obtain a C-PNTs / Cu composite powder. The reaction principle is shown in (1)(2)(3)(4):

[0020] Cu(Ac)2·H2O + 2NaOH → Cu(OH)2↓ + 2NaAc+ H2O (1)

[0021] Cu(OH)2 → CuO↓ + H2O (2)

[0022] 2CuO + C6H 12 O6 + NaOH → Cu2O↓ + C6H 11 O7Na + H2O (3)

[0023] Cu2O + H2 → 2Cu + H2O (4)

[0024] (4) Preparation of C-PNSs / Cu composite powder

[0025] Weigh 0.3 g to 3 g of the C-PNSs powder prepared in step (2) and 15 g to 150 g of Cu powder into a ball mill, add alcohol, and use argon as a protective gas. After ball milling for 120 min to 180 min, the powder is vacuum dried to obtain a C-PNSs / Cu flaky composite powder. The flaky powder has a large specific surface area, which can effectively improve the interface bonding between C-PNSs and the Cu matrix on the one hand; on the other hand, it is convenient to cold-weld the uniformly dispersed C-PNSs inside the Cu powder during subsequent ball milling.

[0026] (5) Preparation of C-PNTs & C-PNSs / Cu composite powders

[0027] 15-150 g of the C-PNTs / Cu composite powder prepared in step (3) and 15-150 g of the C-PNSs / Cu composite powder prepared in step (4) were weighed and placed in a ball mill. Alcohol was added and argon was used as a protective gas. After ball milling for 120-180 min, the powder was vacuum dried to obtain a C-PNTs & C-PNSs / Cu composite powder. At this point, the C-PNTs were uniformly dispersed, and the C-PNSs were cold-welded and coated within the Cu powder.

[0028] (6) Preparation of C-PNTs & C-PNSs / Cu composites

[0029] Weigh 30 g to 300 g of the C-PNTs & C-PNSs / Cu composite powder obtained in step (5) and place it in a fast hot pressing sintering furnace (FHP). Use Ar as the protective gas and evacuate the furnace to a vacuum for sintering. After sintering and heat preservation, turn off the vacuum, turn off the instrument, and take out the sample after the furnace cools to room temperature to obtain a C-PNTs & C-PNSs / Cu composite block.

[0030] For further optimization, the preparation order of step (1) and step (2) can be swapped; the preparation order of step (3) and step (4) can be swapped.

[0031] Further optimization, in step (1), the ratio of C-PNTs powder is 0.1wt% to 0.2wt% (calculated based on the total amount); the particle size is 100nm to 200nm; and the morphology is tubular particles.

[0032] Further optimization, in step (1), vacuum drying adopts vacuum rotary evaporation equipment, and its rotation speed is ≤50r / min.

[0033] Further optimization, in step (2), the ratio of C-PNSs powder is 0.1wt% to 0.2wt% (calculated based on the total amount); the particle size is 100nm to 200nm; and the morphology is spherical particles.

[0034] Further optimization, in the step (3), the vacuum reduction heating rate is 5°C / min to 10°C / min, the holding temperature is 300°C to 400°C, the holding time is 200min to 300min, and Ar / H2 is used as the protective reducing gas.

[0035] Further optimization, in step (3), CuAc·H2O is analytically pure (AR≥99%); NaOH is analytically pure (AR≥99%); and glucose is analytically pure (AR≥99%).

[0036] Further optimization, in step (3), the vacuum tube furnace heating rate is 5°C / min to 10°C / min, the holding temperature is 300°C to 400°C; the holding time is 200min to 300min, and Ar / H2 is used as the protective reducing gas.

[0037] Further optimization, in step (4), the amount of alcohol added is 1 / 4 to 1 / 3 of the volume of the ball mill; the ball-to-material ratio is 10:1 to 15:1; the ball milling time is 120 min to 180 min; and the ball milling speed is 200 r / min to 250 r / min.

[0038] Further optimization, in step (4), the particle size of the C-PNSs / Cu composite powder is 20 μm to 50 μm, and the morphology is spherical, flaky or any irregular shape.

[0039] Further optimization, in step (5), the particle size of the C-PNTs & C-PNSs / Cu composite powder is 20 μm to 50 μm; the morphology is spherical or flaky, or any irregular shape.

[0040] Further optimization, in step (6), the initial vacuum degree of the rapid hot pressing sintering furnace is 5×10 -4 ~10 -3 Pa; the heating rate is 50℃ / min~100℃ / min, the sintering temperature is 600℃~700℃, and the holding time is 10min~15min.

[0041] Beneficial effects of the present invention:

[0042] (1) The present invention proposes a method for stably preparing a low-dimensional carbonized polypyrrole synergistically reinforced copper-based composite material, by introducing a composite reinforcement of carbonized polypyrrole nanotubes C-PNTs and carbonized polypyrrole spheres C-PNSs into a copper matrix. Due to the synergistic effect of C-PNTs and C-PNSs, C-PNTs enhances load transfer reinforcement, C-PNSs promotes the capture and accumulation of dislocations, and enhances strain hardening ability. At the same time, the two jointly refine the grains, so that the prepared composite material achieves good strength-plasticity matching, obtains excellent strength-plasticity synergistic effect, and significantly improves the comprehensive mechanical properties of the material.

[0043] (2) The C-PNSs introduced by the method of the present invention form local conductive graphite channels in the composite material, generate a strong electric field with low charge loss, and effectively promote charge transfer; at the same time, the π-π conjugated interaction between C-PNSs and C-PNTs also accelerates the interfacial charge transfer rate, reduces resistance, and improves the overall conductivity, breaking the contradictory relationship between mechanical properties and electrical properties in traditional copper-based composite materials. Therefore, the copper-based composite material prepared by the method of the present invention exhibits excellent mechanical properties and conductive properties, providing technical guidance for the development of high-performance copper-based composite materials for application in the field of power electronic materials, especially for research on cable materials, motor materials, lead frame materials, and integrated circuit heat sink materials.

[0044] (3) The method of the present invention achieves a microstructural design by regulating the microstructure, introducing C-PNSs inside the grains and C-PNTs at the grain boundaries. This unique structural design overcomes the inherent defects of a single reinforcement and gives full play to the respective advantages of C-PNTs and C-PNSs. Compared with graphene and carbon nanotubes as reinforcements, the present invention uses C-PNTs and C-PNSs to synergistically reinforce copper-based composites, achieving high-efficiency output at a low cost, providing new strategies and ideas for the design and preparation of high-performance copper-based composites, and promoting the progress of material research and development in this field. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces and illustrates the drawings required for use in the embodiments.

[0046] Figure 1 This is a transmission electron microscopy (TEM) image of the C-PNTs powder in step (1) of Example 1;

[0047] Figure 2 This is a transmission electron microscopy (TEM) image of the C-PNSs powder in step (2) of Example 1;

[0048] Figure 3 This is a scanning electron microscope image (SEM) of the C-PNTs / Cu powder prepared by the molecular-level mixing method in step (3) of Example 1;

[0049] Figure 4 This is a scanning electron micrograph (SEM) of the C-PNSs / Cu powder prepared by ball milling in step (4) of Example 1;

[0050] Figure 5 The bar graphs are of the conductivity and hardness changes of the 0.1% C-PNTs&C-PNSs / Cu composite material and the 0.1% C-PNTs / Cu material in Example 1 and Comparative Example 1;

[0051] Figure 6 These are the stress-strain curves of the 0.1% C-PNTs&C-PNSs / Cu composite material and the 0.1% C-PNTs / Cu material in Example 1 and Comparative Example 1.

[0052] Figure 7 The bar graphs are of the conductivity and hardness changes of the 0.2% C-PNTs&C-PNSs / Cu composite material and the 0.2% C-PNTs / Cu material in Example 2 and Comparative Example 2;

[0053] Figure 8 These are the stress-strain curves of the 0.2% C-PNTs&C-PNSs / Cu composite material and the 0.2% C-PNTs / Cu material in Example 2 and Comparative Example 2.

[0054] Figure 9 The bar graphs are of the conductivity and hardness changes of the 0.15% C-PNTs & C-PNSs / Cu composite material and the 0.15% C-PNTs / Cu material in Example 3 and Comparative Example 3;

[0055] Figure 10 The stress-strain curves of the 0.15% C-PNTs&C-PNSs / Cu composite material and the 0.15% C-PNTs / Cu material in Example 3 and Comparative Example 3 are shown; DETAILED DESCRIPTION

[0056] The present invention is further described below with reference to the accompanying drawings and specific embodiments, wherein the methods are conventional methods unless otherwise specified, and the raw materials can be obtained from public commercial channels unless otherwise specified.

[0057] In the following embodiments:

[0058] The purity of the C-PNTs powder is 99.9%, and the diameter is 100nm to 200nm. The C-PNTs powder ratio is 0.1wt% to 0.2wt% (calculated based on the total amount). It is homemade.

[0059] The C-PNSs powder has a purity of 99.9% and a diameter of 100 nm to 200 nm. The C-PNSs powder ratio is 0.1 wt% to 0.2 wt% (calculated based on the total amount). It is self-made.

[0060] CuAc·H O, NaOH, and glucose were all analytical grade (AR ≥ 99%) and were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0061] The purity of Cu powder is 99.9%, the particle size is 20μm to 50μm, and the morphology can be spherical, flake, or any irregular shape. Shanghai Naio Nano Technology Co., Ltd.

[0062] Scanning electron microscope: Nova Nano-450, FEI, USA;

[0063] Transmission electron microscope: SA 58000x, FEI, USA;

[0064] Mechanical properties of the C-PNTs and C-PNSs / Cu composites prepared in the Examples and Comparative Examples were characterized using a universal tensile testing machine (AUTOGRAPH AG-I, Shimadzu Corporation, Japan) at room temperature. The specimen dimensions (dogbone type) were: 16 mm × 2 mm × 1.5 mm (length × width × thickness); the tensile rate was 0.2 mm / min.

[0065] Example 1

[0066] A method for preparing a low-dimensional carbonized polypyrrole-reinforced copper-based composite material is described. Polypyrrole nanotubes (PNTs) and polypyrrole nanospheres (PNSs) are first prepared by chemical synthesis. Carbonized polypyrrole tubes (C-PNTs) and carbonized polypyrrole spheres (C-PNSs) are then carbonized to form the synergistic reinforcements. A molecular-level blending method (MLM) combined with staged ball milling is used to obtain the C-PNTs & C-PNSs / Cu composite powder. This powder is then subjected to rapid hot pressing (FHP) to yield the C-PNTs & C-PNSs / Cu composite material.

[0067] The specific steps are as follows:

[0068] (1) Preparation of carbonized polypyrrole nanotube (C-PNTs) reinforcement

[0069] Weigh 1g of FeCl3·6H2O (99%) brown-yellow powder and put it into a 100ml beaker, then add 30ml of deionized water and ultrasonically disperse it for 10 minutes. After the ultrasonication is completed, place it on a magnetic stirrer and stir it for later use; weigh 0.1g of methyl orange (MO, 99%) orange powder and put it into a 500ml beaker, then add 100ml of deionized water and ultrasonically disperse it for 10 minutes. After the ultrasonication is completed, place it on a magnetic stirrer and stir it for later use; slowly drip FeCl3·6H2O solution into the methyl orange solution to mix. Subsequently, use a pipette to extract 420μL of pyrrole (98%) and slowly drip it into the mixed solution, and stir it at room temperature for 12h. Afterwards, functional PNTs powder is obtained by filtration and vacuum drying. Afterwards, inert gas is introduced into a vacuum tube furnace and carbonized at 650°C to obtain C-PNTs powder. The morphology is as follows Figure 1 shown.

[0070] (2) Preparation of carbonized polypyrrole nanospheres (C-PNSs) reinforcement

[0071] Weigh 1g of FeCl3·6H2O (99%) brown-yellow powder into a 500ml beaker, then add 100ml of deionized water for ultrasonic dispersion for 10 minutes. After ultrasonication, place it on a magnetic stirrer for stirring. Subsequently, use a pipette to extract 420μL of pyrrole (98%) and slowly drip it into the FeCl3·6H2O solution, and stir it at room temperature for 12h. After that, functional PNSs powder is obtained by filtration and vacuum drying. After that, inert gas is introduced into a vacuum tube furnace and carbonized at 650°C to obtain spherical particle C-PNSs powder with a particle size of 100nm. The morphology is as follows Figure 2 shown.

[0072] (3) Preparation of C-PNTs / Cu composite powder

[0073] The carbonized polypyrrole tube (C-PNTs) powder obtained in step (1) was weighed 0.3 g and 15 g of hydrated copper acetate (CuAc·H2O) and ultrasonically dispersed in deionized water for 10 minutes respectively. The C-PNTs dispersion solution was added to the CuAc·H2O solution and stirred in a 60°C water bath for 30 minutes to obtain a C-PNTs / CuAc mixed solution. Subsequently, 9 g of sodium hydroxide (0.5 mol / L) and 7 g of glucose (0.8 mol / L) were weighed and dispersed into a solution and then added to the above mixed solution in sequence. When the color of the solution changed from dark blue to brick red, stirring was stopped, and C-PNTs / Cu2O powder was obtained by filtration and vacuum drying. Finally, the above powder was reduced at 300°C for 200 minutes in a vacuum tube furnace with Ar / H2 as protective reducing gas at a heating rate of 5°C / min to obtain C-PNTs / Cu composite powder. The morphology is as follows. Figure 3 shown.

[0074] (4) Preparation of C-PNSs / Cu composite powder

[0075] Weigh 0.3g of the C-PNSs powder prepared in step (2) and 15g of Cu powder into a ball mill, add 1 / 4 of the volume of the ball mill to alcohol, and use argon as the protective gas. After ball milling at a speed of 200r / min for 120min, the powder is vacuum dried to obtain C-PNSs / Cu flaky composite powder. The flaky powder has a large specific surface area. On the one hand, it can effectively improve the interface bonding between C-PNSs and Cu matrix; on the other hand, it is convenient to cold-weld the uniformly dispersed C-PNSs inside the Cu powder in the subsequent ball milling. The morphology is as follows Figure 4 shown.

[0076] (5) Preparation of C-PNTs & C-PNSs / Cu composite powders

[0077] 15 g of the C-PNTs / Cu composite powder prepared in step (3) and 15 g of the C-PNSs / Cu composite powder prepared in step (4) were weighed and placed in a ball mill. Alcohol was added and the mixture was milled at 200 rpm for 120 min using argon as a protective gas. The powder was then vacuum dried to obtain a C-PNTs & C-PNSs / Cu composite powder. At this point, the C-PNTs were uniformly dispersed, and the C-PNSs were cold-welded and coated within the Cu powder.

[0078] (6) Preparation of C-PNTs & C-PNSs / Cu composites

[0079] Weigh 30 g of the C-PNTs & C-PNSs / Cu composite powder obtained in step (5) and evacuate the furnace body to vacuum (with Ar as protective gas) in a fast hot pressing sintering furnace (FHP), sinter at 600 ° C, keep warm for 10 minutes, turn off the vacuum, turn off the instrument, and take out the sample after the furnace cools to room temperature (about 20 minutes) to obtain a C-PNTs & C-PNSs / Cu composite material.

[0080] Comparative Example 1

[0081] Weigh 30 g of C-PNTs / Cu composite powder prepared by the same process as in step (3) and evacuate the furnace body to vacuum (with Ar as protective gas) in a fast hot pressing furnace (FHP). Sinter at 600°C and keep warm for 10 minutes. Then turn off the vacuum and the instrument. After the furnace cools to room temperature (about 20 minutes), take out the sample to obtain a C-PNTs / Cu composite material.

[0082] The conductivity and hardness of the composite materials prepared in Example 1 and Comparative Example 1 were tested. The results are as follows: Figure 5 As shown; the mechanical properties test results are as follows Figure 6 shown.

[0083] like Figure 5As shown, the performance of the composite material synergistically reinforced by C-PNTs and C-PNSs is even better. Comparing Example 1 and Comparative Example 1, the composite material of Example 1 still maintains good electrical conductivity (about 98% IACS). As for hardness, the composite material of Example 1 is significantly improved compared with the material of Comparative Example 1, from 101HV to 120HV, an increase of about 18.8%. The main reasons for this phenomenon are: on the one hand, Example 1 introduces uniformly dispersed C-PNTs at the grain boundaries by the MLM method, and introduces uniformly dispersed C-PNSs at the grain boundaries by ball milling, which effectively improves the interface bonding between the reinforcement and the matrix; on the other hand, the C-PNTs and C-PNSs prepared in Example 1 show obvious corrugated structure and strong roughness on their side walls, and further improve the dislocation storage density by pinning dislocation slip. The synergistic effect of C-PNTs and C-PNSs significantly improves the comprehensive mechanical properties of the material. However, the control group added a single reinforcement, resulting in lower performance than Example 1.

[0084] like Figure 6 As shown, the tensile strength of the composite material of Example 1 is significantly improved compared to that of the composite material of Comparative Example 1, reaching approximately 322 MPa, an increase of approximately 43.8%. This is mainly attributed to the synergistic effect of C-PNTs and C-PNSs: C-PNTs enhance load transfer and strengthening, while C-PNSs promote the capture and accumulation of dislocations, enhancing strain hardening ability. At the same time, both together refine the grain size, significantly improving the overall mechanical properties of the material.

[0085] Example 2

[0086] A method for preparing a low-dimensional carbonized polypyrrole synergistically reinforced copper-based composite material, comprising the following steps:

[0087] (1) Preparation of carbonized polypyrrole nanotube (C-PNTs) reinforcement

[0088] Weigh 3g of FeCl3·6H2O (99%) brown-yellow powder and put it into a 100ml beaker, then add 30ml of deionized water and ultrasonically disperse it for 20 minutes. After the ultrasonication is completed, place it on a magnetic stirrer and stir it for later use; weigh 0.3g of methyl orange (MO, 99%) orange powder and put it into a 500ml beaker, then add 100ml of deionized water and ultrasonically disperse it for 20 minutes. After the ultrasonication is completed, place it on a magnetic stirrer and stir it for later use; slowly drip FeCl3·6H2O solution into the methyl orange solution to mix. Subsequently, use a pipette to extract 420μL of pyrrole (98%) and slowly drip it into the mixed solution, and stir it at room temperature for 24h. Afterwards, functional PNTs powder is obtained by filtration and vacuum drying. Then, inert gas is introduced into a vacuum tube furnace and carbonized at 1000°C to obtain C-PNTs powder. The morphology is as follows Figure 1 shown.

[0089] (2) Preparation of carbonized polypyrrole nanospheres (C-PNSs) reinforcement

[0090] Weigh 3g of FeCl3·6H2O (99%) brown-yellow powder into a 500ml beaker, then add 100ml of deionized water for ultrasonic dispersion for 20min. After ultrasonication, place it on a magnetic stirrer for stirring. Subsequently, use a pipette to extract 420μL of pyrrole (98%) and slowly drip it into the FeCl3·6H2O solution, and stir it at room temperature for 24h. After that, functional PNSs powder is obtained by filtration and vacuum drying. After that, inert gas is introduced into a vacuum tube furnace and graphitized at 1000℃ to obtain spherical particle C-PNSs powder with a particle size of 200nm, and the morphology is as follows. Figure 2 shown.

[0091] (3) Preparation of C-PNTs / Cu composite powder

[0092] The carbonized polypyrrole tube (C-PNTs) powder obtained in step (1) was weighed 3 g and 150 g of hydrated copper acetate (CuAc·H2O) were ultrasonically dispersed in deionized water for 20 min respectively, and the C-PNTs dispersion solution was added to the CuAc·H2O solution, and stirred in an 80°C water bath for 60 min to obtain a C-PNTs / CuAc mixed solution. Subsequently, 90 g of sodium hydroxide (0.5 mol / L) and 70 g of glucose (0.8 mol / L) were weighed and dispersed into a solution and then added to the above mixed solution in sequence. When the color of the solution changed from dark blue to brick red, stirring was stopped, and C-PNTs / Cu2O powder was obtained by filtration and vacuum drying. Finally, the above powder was reduced at 400°C for 300 min in a vacuum tube furnace with Ar / H2 as protective reducing gas at a heating rate of 10°C / min to obtain C-PNTs / Cu composite powder. The morphology is as follows. Figure 3 shown.

[0093] (4) Preparation of C-PNSs / Cu composite powder

[0094] Weigh 3g of the C-PNSs powder prepared in step (2) and 150g of Cu powder into a ball mill, add 1 / 3 of the volume of the ball mill to alcohol, and use argon as the protective gas. After ball milling at a speed of 250r / min for 180min, the powder is vacuum dried to obtain C-PNSs / Cu flaky composite powder. The flaky powder has a large specific surface area. On the one hand, it can effectively improve the interface bonding between C-PNSs and Cu matrix; on the other hand, it is convenient to cold-weld the uniformly dispersed C-PNSs inside the Cu powder during subsequent ball milling. The morphology is as follows: Figure 4 shown.

[0095] (5) Preparation of C-PNTs & C-PNSs / Cu composite powders

[0096] 150 g of the C-PNTs / Cu composite powder prepared in step (3) and 150 g of the C-PNSs / Cu composite powder prepared in step (4) were weighed and placed in a ball mill. Alcohol was added and the mixture was milled at 250 rpm for 180 min using argon as a protective gas. The powder was then vacuum dried to obtain a C-PNTs & C-PNSs / Cu composite powder. At this point, the C-PNTs were uniformly dispersed, and the C-PNSs were cold-welded and coated within the Cu powder.

[0097] (6) Preparation of C-PNTs & C-PNSs / Cu composites

[0098] Weigh 300 g of the C-PNTs & C-PNSs / Cu composite powder obtained in step (5) and evacuate the furnace body to vacuum (with Ar as protective gas) in a rapid hot pressing sintering furnace (FHP), sinter at 700 ° C, keep warm for 15 minutes, turn off the vacuum, turn off the instrument, and take out the sample after the furnace cools to room temperature (about 20 minutes) to obtain a C-PNTs & C-PNSs / Cu composite material.

[0099] Comparative Example 2

[0100] Weigh 300 g of C-PNTs / Cu composite powder prepared by the same process as in step (3) and evacuate the furnace body to vacuum (with Ar as protective gas) in a fast hot pressing furnace (FHP). Sinter at 700°C and keep warm for 15 minutes. Then turn off the vacuum and the instrument. After the furnace cools to room temperature (about 20 minutes), take out the sample to obtain a C-PNTs / Cu composite material.

[0101] The conductivity and hardness of the composite materials prepared in Example 2 and Comparative Example 2 were tested. The results are as follows: Figure 7 As shown; the mechanical properties test results are as follows Figure 8 shown.

[0102] like Figure 7As shown, the same as Example 1, the performance of the composite material synergistically enhanced by C-PNTs and C-PNSs is even better. The electrical conductivity of the composite material of Example 2 is slightly higher than that of Comparative Example 2. This is mainly because the reinforcement content is further increased, which plays a role in improving the scattering effect during electron transmission. C-PNSs forms a local conductive graphite channel in the composite material, generating a strong electric field with low charge loss, which effectively promotes charge transfer. At the same time, the π-π conjugated interaction between C-PNSs and C-PNTs also accelerates the interface charge transfer rate, reduces resistance, and improves overall conductivity. However, the excessive reinforcement content (0.2wt%) causes large-scale agglomeration of the reinforcement, resulting in debonding of the interface between the reinforcement and the matrix, which is also the reason why its hardness is reduced compared to Example 1.

[0103] like Figure 8 As shown, the tensile strength of the composite material of Example 2 is somewhat enhanced compared to that of the composite material of Comparative Example 2, but the effect is not significant. This is also because the excessive reinforcement content (0.2 wt%) causes large-scale agglomeration of the reinforcement, which reduces the performance. The strengthening mechanism is basically the same as that of Example 1.

[0104] Example 3

[0105] A method for preparing a low-dimensional carbonized polypyrrole synergistically reinforced copper-based composite material, comprising the following steps:

[0106] (1) Preparation of carbonized polypyrrole nanotube (C-PNTs) reinforcement

[0107] Weigh 1.5g of FeCl3·6H2O (99%) brown-yellow powder and put it into a 100ml beaker, then add 30ml of deionized water and ultrasonically disperse it for 15 minutes. After the ultrasonication is completed, place it on a magnetic stirrer and stir it for later use; weigh 0.15g of methyl orange (MO, 99%) orange powder and put it into a 500ml beaker, then add 100ml of deionized water and ultrasonically disperse it for 15 minutes. After the ultrasonication is completed, place it on a magnetic stirrer and stir it for later use; slowly drip FeCl3·6H2O solution into the methyl orange solution to mix. Subsequently, use a pipette to extract 420μL of pyrrole (98%) and slowly drip it into the mixed solution, and stir it at room temperature for 18h. Afterwards, functional PNTs powder is obtained by filtration and vacuum drying. Afterwards, inert gas is introduced into a vacuum tube furnace and carbonized at 900°C to obtain C-PNTs powder. The morphology is as follows Figure 1 shown.

[0108] (2) Preparation of carbonized polypyrrole nanospheres (C-PNSs) reinforcement

[0109] Weigh 1.5g of FeCl3·6H2O (99%) brown-yellow powder into a 500ml beaker, then add 100ml of deionized water for ultrasonic dispersion for 15 minutes. After ultrasonication, place it on a magnetic stirrer for stirring. Subsequently, use a pipette to extract 420μL of pyrrole (98%) and slowly drip it into the FeCl3·6H2O solution, and stir it at room temperature for 18h. Functional PNSs powder is then obtained by filtration and vacuum drying. After that, inert gas is introduced into a vacuum tube furnace and carbonized at 900°C to obtain C-PNSs powder with the morphology shown below. Figure 2 shown.

[0110] (3) Preparation of C-PNSs / Cu composite powder

[0111] 1.5 g of the carbonized polypyrrole sphere (C-PNSs) powder obtained in step (1) and 70 g of hydrated copper acetate (CuAc·H2O) were weighed and ultrasonically dispersed in deionized water for 15 min. The C-PNSs dispersion solution was added to the CuAc·H2O solution and stirred in a 70°C water bath for 45 min to obtain a C-PNSs / CuAc mixed solution. Subsequently, 45 g of sodium hydroxide (0.5 mol / L) and 45 g of glucose (0.8 mol / L) were weighed and dispersed into a solution and then added to the mixed solution in sequence. Stirring was stopped when the color of the solution changed from dark blue to brick red. The C-PNSs / Cu2O powder was obtained by filtration and vacuum drying. Finally, the powder was reduced at 350°C for 250 min in a vacuum tube furnace with Ar / H2 as a protective reducing gas at a heating rate of 7°C / min to obtain a C-PNSs / Cu composite powder.

[0112] (4) Preparation of C-PNSs / Cu composite powder

[0113] Weigh 1.5g of the C-PNSs powder prepared in step (2) and 75g of Cu powder into a ball mill, add alcohol, and use argon as the protective gas. After ball milling at a speed of 220r / min for 150min, the powder is vacuum dried to obtain C-PNSs / Cu flaky composite powder. The flaky powder has a large specific surface area. On the one hand, it can effectively improve the interface bonding between C-PNSs and Cu matrix; on the other hand, it is convenient to cold-weld the uniformly dispersed C-PNSs inside the Cu powder during subsequent ball milling. The morphology is as follows: Figure 4 shown.

[0114] (5) Preparation of C-PNTs & C-PNSs / Cu composite powders

[0115] 75 g of the C-PNTs / Cu composite powder prepared in step (3) and 75 g of the C-PNSs / Cu composite powder prepared in step (4) were weighed and placed in a ball mill. Alcohol was added and the mixture was milled at 220 r / min for 150 min using argon as a protective gas. The powder was then vacuum dried to obtain a C-PNTs & C-PNSs / Cu composite powder. At this point, the C-PNTs were uniformly dispersed, and the C-PNSs were cold-welded and coated within the Cu powder.

[0116] (6) Preparation of C-PNTs & C-PNSs / Cu composites

[0117] Weigh 150 g of the C-PNTs & C-PNSs / Cu composite powder obtained in step (5) and evacuate the furnace body to vacuum (with Ar as protective gas) in a rapid hot pressing sintering furnace (FHP). Sinter at 650 ° C. After keeping warm for 12 minutes, turn off the vacuum, turn off the instrument, and take out the sample after the furnace cools to room temperature (about 20 minutes) to obtain a C-PNTs & C-PNSs / Cu composite material.

[0118] Comparative Example 3

[0119] Weigh 150 g of C-PNTs / Cu composite powder prepared by the same process as in step (3) and evacuate the furnace body to vacuum (with Ar as protective gas) in a fast hot pressing furnace (FHP). Sinter at 650°C and keep warm for 12 minutes. Then turn off the vacuum and the instrument. After the furnace cools to room temperature (about 20 minutes), take out the sample to obtain a C-PNTs / Cu composite material.

[0120] The conductivity and hardness of the composite materials prepared in Example 3 and Comparative Example 3 were tested. The results are as follows: Figure 9 As shown; the mechanical properties test results are as follows Figure 10 The tensile strength of the C-PNTs & C-PNSs / Cu composite material in this example reached approximately 407 MPa, an increase of approximately 30.9% compared to the comparative C-PNTs / Cu composite material. The composite material prepared in Example 3 exhibited superior performance compared to Examples 1 and 2; its reinforcement mechanism was a moderate reinforcement content, resulting in excellent reinforcement effects. Other reinforcement mechanisms were essentially the same as those in Example 1.

[0121] In summary, the present invention provides a method for preparing a low-dimensional carbonized polypyrrole synergistically reinforced copper-based composite material. The preparation method is simple, the experimental cycle is short and the practicability is strong, and the obtained composite material can still maintain good electrical conductivity while having good strength-plasticity matching. The dispersibility and interfacial wettability of C-PNTs are improved by molecular-level mixing. Intragranular C-PNSs promote the capture and accumulation of dislocations inside the grains, thereby enhancing the strain hardening ability, so that C-PNTs & C-PNSs / Cu composite materials achieve good strength-plasticity matching, which can effectively solve the problems in the background technology. The obtained copper-based composite material shows excellent mechanical properties and electrical conductivity, and provides technical guidance for the development of high-performance copper-based composite materials, which are applied to the field of power electronic materials, especially as cable materials, motor materials, lead frame materials and integrated circuit heat sink materials.

[0122] The embodiments described above are only preferred embodiments of the present invention, and are not exhaustive embodiments. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments obtained by those skilled in the art through any modification, replacement, improvement, etc. based on the embodiments of the present invention without any innovation shall fall within the scope of protection of the present invention.

Claims

1. A method for preparing a low-dimensional carbonized polypyrrole synergistically reinforced copper-based composite material, characterized by: The method comprises the following steps: (1) Preparation of carbonized polypyrrole nanotubes (C-PNTs) reinforcement FeCl3·6H2O powder was ultrasonically dispersed in deionized water and stirred for later use; methyl orange MO powder was ultrasonically dispersed in deionized water and stirred for later use; FeCl3·6H2O solution was slowly dripped into the methyl orange solution to mix, and then pyrrole was extracted with a pipette and slowly dripped into the mixed solution, followed by stirring, filtration and vacuum drying to obtain functional PNTs powder, which was then carbonized in a vacuum tube furnace to obtain C-PNTs powder; (2) Preparation of carbonized polypyrrole nanospheres C-PNSs reinforcement FeCl3·6H2O powder was ultrasonically dispersed in deionized water and stirred for later use. Subsequently, pyrrole was extracted with a pipette and slowly dripped into the FeCl3·6H2O solution. The mixture was stirred, filtered, and vacuum-dried to obtain functional PNSs powder. The powder was then carbonized in a vacuum tube furnace to obtain C-PNSs powder. (3) Preparation of C-PNTs / Cu composite powder The C-PNTs powder and CuAc·H2O prepared in step (1) are ultrasonically dispersed separately, and the C-PNTs dispersion solution is then added to the CuAc·H2O solution and stirred to obtain a C-PNTs / CuAc mixed solution, followed by sequential addition of sodium hydroxide and glucose solution, followed by stirring, filtering, drying, and reduction to obtain a C-PNTs / Cu composite powder; (4) Preparation of C-PNSs / Cu composite powder The C-PNSs powder and Cu powder prepared in step (2) were placed in a ball mill, alcohol was added, and ball milling was performed using argon as a protective gas. The powder was then vacuum dried to obtain a C-PNSs / Cu composite powder; (5) Preparation of C-PNTs & C-PNSs / Cu composite powders The C-PNTs / Cu composite powder prepared in step (3) and the C-PNSs / Cu composite powder prepared in step (4) were placed in a ball mill, and alcohol was added. Argon was used as a protective gas, and the ball milling was carried out for 120 to 180 minutes. The powder was then vacuum dried to obtain a C-PNTs & C-PNSs / Cu composite powder; (6) Preparation of C-PNTs & C-PNSs / Cu composites The C-PNTs & C-PNSs / Cu composite powder obtained in step (5) is placed in a rapid hot pressing sintering furnace, the furnace body is evacuated to a vacuum for sintering, the vacuum is turned off after heat preservation, the instrument is turned off, and the sample is taken out after the furnace is cooled to room temperature to obtain a C-PNTs & C-PNSs / Cu composite block.

2. The method for preparing a low-dimensional carbonized polypyrrole synergistically reinforced copper-based composite material according to claim 1, characterized in that: The specific operation of preparing the carbonized polypyrrole nanotube (C-PNTs) reinforcement in step (1) is as follows: Weigh 1g~3g of FeCl3·6H2O brown-yellow powder and put it into a 100ml beaker, then add 30ml of deionized water and ultrasonically disperse it for 10min~20min. After the ultrasonication is completed, place it on a magnetic stirrer and stir it for later use; weigh 0.1g~0.3g of methyl orange MO orange powder and put it into a 500ml beaker, then add 100ml of deionized water and ultrasonically disperse it for 10min~20min. After the ultrasonication is completed, place it on a magnetic stirrer and stir it for later use; slowly drop the FeCl3·6H2O solution into the methyl orange solution to mix, then use a pipette to draw 420μL of pyrrole and slowly drop it into the mixed solution, and stir it at room temperature for 12~24h, then filter and vacuum dry to obtain functional PNTs powder, and finally pass inert gas into a vacuum tube furnace at 650℃~1000℃ for carbonization to obtain C-PNTs powder.

3. The method for preparing a low-dimensional carbonized polypyrrole synergistically reinforced copper-based composite material according to claim 1, characterized in that: The specific operation of preparing the carbonized polypyrrole nanospheres (C-PNSs) reinforcement (2) is as follows: Weigh 1g~3g FeCl3·6H2O powder into a beaker, then add 100ml deionized water and ultrasonically disperse it for 10min~20min. After the ultrasonication is completed, place it on a magnetic stirrer and stir it for later use; then, use a pipette to extract 420μL of pyrrole and slowly drip it into the FeCl3·6H2O solution, and stir it at room temperature for 12~24h; then, obtain functional PNSs powder by filtration and vacuum drying; finally, introduce inert gas into a vacuum tube furnace and carbonize it at 650℃~1000℃ to obtain C-PNSs powder.

4. The method for preparing a low-dimensional carbonized polypyrrole synergistically reinforced copper-based composite material according to claim 1, characterized in that: The specific operation of preparing the C-PNTs / Cu composite powder in step (3) is as follows: 0.3 g to 3 g of the carbonized polypyrrole tube C-PNTs powder prepared in step (1) and 15 g to 150 g of hydrated copper acetate CuAc·H2O are weighed and ultrasonically dispersed in deionized water for 10 min to 20 min for later use. The C-PNTs dispersed solution is then added to the CuAc·H2O solution, and the mixture is stirred in a water bath at 60° C. to 80° C. for 30 min to 60 min to obtain a C-PNTs / CuAc mixed solution. Subsequently, 9 g to 90 g of sodium hydroxide and 7 g to 70 g of glucose are weighed and dispersed into a solution, and the solution is then added to the mixed solution in sequence. Stirring is stopped when the color of the solution changes from dark blue to brick red, and C-PNTs / Cu2O powder is obtained by filtration and vacuum drying. Finally, the powder is placed in a vacuum tube furnace and vacuum reduced to obtain a C-PNTs / Cu composite powder.

5. The method for preparing a low-dimensional carbonized polypyrrole synergistically reinforced copper-based composite material according to claim 1 or 4, characterized in that: In step (3), the vacuum reduction heating rate is 5°C / min to 10°C / min, the holding temperature is 300°C to 400°C, the holding time is 200min to 300min, and Ar / H2 is used as the protective reducing gas.

6. The method for preparing a low-dimensional carbonized polypyrrole synergistically reinforced copper-based composite material according to claim 1, characterized in that: In step (4), the amount of alcohol added is 1 / 4 to 1 / 3 of the volume of the ball mill; the ball-to-material ratio is 10:1 to 15:1; the ball milling time is 120 min to 180 min; and the ball milling speed is 200 r / min to 250 r / min.

7. The method for preparing a low-dimensional carbonized polypyrrole synergistically reinforced copper-based composite material according to claim 1, characterized in that: In step (6), the heating rate of the rapid hot pressing sintering furnace is 50°C / min to 100°C / min; the sintering temperature is 600°C to 700°C; and the holding time is 10min to 15min.

8. The method for preparing a low-dimensional carbonized polypyrrole synergistically reinforced copper-based composite material according to claim 1, characterized in that: In step (1), the C-PNTs powder has a ratio of 0.1 wt% to 0.2 wt%, a particle size of 100 nm to 200 nm, and a morphology of tubular particles; in step (2), the C-PNSs powder has a ratio of 0.1 wt% to 0.2 wt%, a particle size of 100 nm to 200 nm, and a morphology of spherical particles.

9. The method for preparing a low-dimensional carbonized polypyrrole synergistically reinforced copper-based composite material according to claim 1 or 4, characterized in that: In step (4), the particle size of the C-PNSs / Cu composite powder is 20 μm to 50 μm, and the morphology is spherical, flaky or any irregular shape; in step (5), the particle size of the C-PNTs&C-PNSs / Cu composite powder is 20 μm to 50 μm, and the morphology is spherical, flaky or any irregular shape.

10. The method for preparing a low-dimensional carbonized polypyrrole synergistically reinforced copper-based composite material according to claim 1, characterized in that: The preparation order of step (1) and step (2) can be exchanged; the preparation order of step (3) and step (4) can be exchanged.

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