In-situ grown carbon nanotube reinforced carbon fiber composite carbon slide

Abstract

The present application relates to a kind of in-situ growth carbon nanotube reinforced carbon fiber composite carbon slide, belong to the material preparation technical field for electric locomotive.The present application in carbon fiber composite material inside, under the premise of not using catalyst, in the inside and outside of coated carbon fiber needle punching integrated felt, carbon nanotube and carbon particle are in-situ grown and control both distribution, combined pitch impregnation-carbonization realizes fast carbonization / graphitization, after high-temperature graphitization treatment, graphitization degree can reach 93%, and preparation process is simple, product mechanics, electric and friction performance are superior, suitable for large-scale industrialization application and production.

Description

Technical Field

[0001] This invention relates to a carbon slider made of carbon nanotube-reinforced carbon fiber composite material, belonging to the field of material preparation technology for electric locomotives. Background Technology

[0002] The pantograph contactor emerged with the advent of electric locomotives. As a core component for electric locomotives to obtain current from the contact wire, its material evolution has progressed from pure metal, pure carbon contactors, powder metallurgy, and metal-impregnated carbon contactors. Currently, the main materials for electric locomotive contactors are pure carbon and metal-impregnated carbon contactors. Pure carbon contactors are obtained by mixing, extruding, and molding graphite, additives, and binders, followed by calcination. Due to the excellent self-lubricating properties of carbon, wear on the contact wire is greatly reduced, significantly extending the contact wire's lifespan. However, pure carbon contactors have poor mechanical properties, with an impact toughness of only 0.2–0.5 J·cm. -2 In actual operation, its service life is very short due to breakage, cracking and uneven wear.

[0003] Building upon pure carbon contact lines, researchers began to obtain metal-impregnated carbon contact lines by pressurizing and impregnating porous carbon matrices with molten Cu. This improved the mechanical properties of the material to some extent and significantly enhanced the electrical conductivity of the carbon contact line. However, it exacerbated wear at the contact points, and due to the non-wetting problem between carbon and copper, the impact toughness of the contact line remained low. During operation, breakage and chipping still occurred, resulting in increased wear. Studies by SHUNICHI KUBO et al. found that during current-carrying friction between the metal-impregnated carbon contact line and the copper contact wire, the wear increased significantly with increasing current density. Furthermore, the uneven micro-region distribution of carbon and copper made this type of contact line more prone to arcing during operation, causing molten copper splashing and evaporation inside the contact line.

[0004] Table 1 Performance of pure carbon sliders and metal-impregnated carbon sliders

[0005]

[0006] Carbon / carbon composites are carbon fiber reinforced carbon matrix composites with outstanding advantages such as high specific strength and specific modulus, as well as excellent thermophysical properties and tribological properties. They are typically obtained through carbon fiber preform weaving, preform densification, and high-temperature graphitization treatment, and their mechanical properties, thermal conductivity, electrical conductivity, and tribological properties can all be adjusted. Numerous studies by domestic and international scholars have reported on C / C composites as sliding plates. Hiroyuki Kinami et al. investigated the use of C / C composite sliding plates on 223 series vehicles operating at 130 km / h on the Sanyo mainline, finding that the friction surface of the sliding plate was smooth and without defects. Yoshitaka Kubota et al. studied the performance of Cu-impregnated C / C composites and found that the resistivity of C / C-Cu composites can be as low as below 0.5 μΩ·m, and the friction film formed during friction helps reduce wear. The wear of carbon sliding plates is positively correlated with the arc energy. High-strength carbon fibers cannot reduce the wear of carbon sliding plates, but heat treatment can change the graphitization degree of carbon in the composite material, thus affecting the wear characteristics of the material.

[0007] Jia Lixiao et al. compared the performance of C / C composite materials with that of imported German pure carbon material skateboards. They found that the resistivity of the C / C composite material was comparable to that of the imported material, but its compressive strength, flexural strength, and impact toughness were increased by 2-3 times. Furthermore, the addition of arc-suppressing oil to the C / C composite material significantly reduced and stabilized its coefficient of friction, reducing the wear rate to one-third of its original value.

[0008] Lin Yang et al. prepared C / C-Cu composites by infiltrating Cu into C / C composites using reactive melt deposition. Their research revealed that the copper in the C / C-Cu composites was distributed in a three-dimensional network within the matrix, with a resistivity as low as below 0.7 μO·m and an impact toughness reaching 2.2 J·cm⁻¹. -2 Furthermore, with the increase of carbon fiber content, both the friction coefficient and wear amount decreased, which is attributed to the formation of a Cu2O friction film on the surface of the C / C-Cu composite material. Gao Yuan et al. studied the current-carrying friction characteristics of carbon fiber fine-woven puncture fabric reinforced copper composite materials prepared by low-pressure impregnation and found that the tribological properties of this composite material were superior to those of pure Cu.

[0009] However, the mechanical, electrical, and tribological properties of existing carbon fiber skateboards need further improvement. Carbon nanotubes, formed by rolling up layers of carbon nanotube sheets, are currently the highest specific strength materials that can be prepared. They possess excellent electrical and thermal conductivity. Doping with trace amounts of carbon nanotubes can significantly improve the strength, elasticity, fatigue resistance, isotropy, electrical and thermal conductivity of composite materials, thus holding potential application value in numerous fields. Adding an appropriate amount of carbon nanotubes to carbon fibers not only improves the material's electrical conductivity but also effectively enhances its tribological properties. However, the cost and dispersion difficulty of carbon nanotubes limit their application.

[0010] Chinese invention patent CN 109484190A (A preparation process for a carbon fiber reinforced carbon pantograph slider) discloses a method for preparing carbon nanotubes. This invention discloses a preparation process for a carbon fiber reinforced carbon pantograph slider, comprising the following steps: Step 1: Mixing graphene powder with conductive epoxy resin and a curing agent to form a paste; Step 2: Applying the paste obtained in Step 1 to the surface of a carbon fiber tube; Step 3: Placing the carbon fiber tube coated with the paste into a carburizing furnace for carburizing treatment to obtain a carburized porous body; Step 4: Immersing the carburized porous body obtained in Step 3 in an impregnation solution containing silver ions for a period of time, then removing and drying it. Step 5: The carburized porous body obtained in Step 4 is placed in a carbonization furnace for carbonization to obtain carbon fiber reinforced carbon tubes; Step 6: Graphite powder, titanium powder, and furan resin are mixed to form a gel; Step 7: Multiple carbon fiber reinforced carbon tubes are glued together with the gel obtained in Step 6 to form a carbon fiber reinforced carbon slider blank; Step 8: Graphite paper is coated on the surface of the carbon fiber reinforced carbon slider blank obtained in Step 7, and then it is placed in a hot isostatic press for hot pressing and curing; Step 9: The carbon fiber reinforced carbon slider blank cured in Step 8 is placed in a carbonization furnace again for carbonization treatment to obtain a carbon fiber reinforced carbon slider. The pantograph slider prepared by this process has high mechanical strength, good lubrication performance and impact resistance, causes less wear on the contact wire, and has good wear resistance.

[0011] Chinese invention patent CN106699181B (A method for preparing carbon slider material for pantographs using graphene oxide) discloses a method for preparing carbon slider material for pantographs using graphene oxide, comprising the following steps: mixing graphene oxide, semi-reinforcing carbon black, graphite powder, and crushed, ground, and sieved pitch coke as aggregate for preparing the carbon slider; adding a binder to the aggregate and then kneading to obtain a paste; pre-pressing the paste; and calcining the pre-pressed paste to finally obtain a material suitable for the pantograph carbon slider. This invention requires only one calcination to obtain the carbon slider material that meets the requirements, resulting in a short production cycle. The pantograph carbon slider prepared by graphene oxide provided by this invention has advantages such as good electrical conductivity, high thermal conductivity, strong friction and wear resistance, and low raw material cost.

[0012] Chinese invention patent CN 117658660 A (A mesophase pitch carbon fiber reinforced pantograph carbon slide plate and its preparation method) discloses a mesophase pitch carbon fiber reinforced pantograph carbon slide plate and its preparation method. The preparation method includes the following steps: (1) Modifying mesophase pitch carbon fiber with an activator, followed by ultrasonic dispersion and vacuum drying to obtain modified mesophase pitch carbon fiber; (2) Dry mixing calcined pitch coke, needle coke, artificial graphite powder, N339 carbon black and modified mesophase pitch carbon fiber to obtain dry powder; (3) Adding molten binder to the dry powder in step (2), then kneading, rolling, and remixing and pressing into a column; (4) Extruding the column, calcining, and pressurizing with copper to obtain the mesophase pitch carbon fiber reinforced pantograph carbon slide plate. The pantograph carbon slide plate prepared by this invention has low resistivity and good mechanical properties, impact toughness and thermal stability.

[0013] Chinese invention patent CN 117403090 A (A graphene-modified copper-based carbon locomotive pantograph contactor and its preparation method) discloses a graphene-modified copper-based carbon locomotive pantograph contactor and its preparation method, belonging to the field of nanomaterials. This method obtains a pantograph contactor for electric locomotives by modifying copper composite metallurgical powder with graphene. The preparation method uniformly disperses solids with large specific gravity differences, ensuring the uniformity of the mixing of the lightweight, easily agglomerated, defect-free graphene within the heavier copper-based carbon composite powder. Compared with existing products, the high-speed electric locomotive pantograph contactor prepared by this method exhibits significantly improved conductivity, good arc burn resistance, significantly improved friction reduction and wear resistance, strong environmental adaptability, and a product lifespan more than doubled. It also has good self-lubricating properties and does not damage the conductor. The production equipment is simple, the production cycle is short, and the process is simple, making it suitable for large-scale production.

[0014] Carbon nanotubes (CNTs) exhibit high surface activity, allowing for effective dispersion in liquids or molten materials using methods such as shear mixing, grinding, and cavitation. The interaction between CNTs and dispersants can be improved to some extent through the addition of surfactants or surface modification, achieving maximum dispersion. However, dispersion becomes more difficult with increasing dosage. Furthermore, directly mixing CNTs with epoxy resins and asphalt does not significantly improve the mechanical properties of the composite. This is primarily because the smooth surface of CNTs results in weak bonding with organic matter, making them prone to relative sliding with the matrix under shear forces, thus preventing the full expression of their superior properties in the composite material. To address the issues of uneven dispersion and weak bonding with the matrix, researchers have proposed in-situ growth of CNTs on carbon fibers. Among all CNT preparation methods, CVD (Continuous Chemical Deposition) is most suitable for in-situ growth. The in-situ growth process involves three steps: 1) surface treatment of the carbon fibers to increase active sites; 2) loading a catalyst onto the carbon fiber surface; and 3) in-situ CVD growth of the carbon nanofibers.

[0015] Currently, the main methods for in-situ preparation of carbon nanotubes on powder include arc discharge, plasma methods, laser evaporation, catalytic pyrolysis, and chemical vapor deposition. The vapor-phase catalytic growth of carbon nanotubes requires catalyst particles, a carbon source, and heating. Commonly used catalysts are transition metals such as iron, cobalt, and nickel, as well as their alloys or metal oxide particles. Catalytic pyrolysis involves breaking down carbon-containing compounds (CO, CH4, C2H2, etc.) into carbon atoms at relatively high temperatures (600-1000℃). These carbon atoms, under the action of a transition metal catalyst, adhere to the surface of the catalyst particles to form carbon nanotubes. This method has relatively simple equipment and processes, and is suitable for large-scale production of carbon nanotubes with high carbon nanotube content. However, the key lies in the preparation and dispersion of the catalyst. Chemical vapor deposition (CVD) utilizes nanoscale transition metals such as Fe, Co, and Ni, or their alloys and compounds, as catalysts. At relatively low temperatures (500-1300℃), a certain proportion of hydrocarbons (such as methane, acetylene, benzene, etc.) and a carrier gas (usually argon) are introduced to catalyze the cracking of the carbon source gas. The carbon nanotubes are then grown on the catalyst particles through decomposition, diffusion, and precipitation. It is a simple, easy, and high-yield method, and is currently one of the most commonly used methods for preparing carbon nanotubes.

[0016] Regardless of whether catalytic cracking or chemical vapor deposition is used, the most crucial step in preparing carbon nanotubes is the preparation and dispersion of the catalyst. Currently, the main catalysts used are transition metal-supported solid catalysts, with transition metals typically being Fe, Co, Ni, and their alloys, and high-temperature resistant oxides such as SiO2, Al2O3, MgO, and zeolites serving as supports. Lyu et al. successfully synthesized single-walled carbon nanotubes using C2H2 and, with an Fe / Mo / Al2O3 catalyst, prepared high-purity, high-yield single-walled carbon nanotubes at 950℃. However, the difficulty in catalyst removal limits the use of supports.

[0017] Chinese invention patent CN104388847B (Method for preparing carbon nanotubes by chemical vapor deposition) discloses a method for preparing carbon nanotubes, which involves preparing carbon nanotubes by chemical vapor deposition, including the following steps: placing a substrate with a catalyst in an oxygen-free reactor, raising the temperature of the substrate to 500-1200°C, and then introducing a carbon-containing substance into the reactor to obtain carbon nanotubes; wherein the catalyst is a metal or a metal compound.

[0018] To date, there are no existing technologies that can generate carbon nanotubes in situ in carbon fiber composite skateboards without the addition of a catalyst, nor are there any reports on the in-situ alternating deposition of carbon particles and carbon nanotubes. Summary of the Invention

[0019] During the technology development process, it was discovered that under certain conditions, carbon nanotubes can be generated in situ on the surface of carbon fibers and graphite particles through chemical vapor deposition without a catalyst. Based on this discovery, this invention was developed.

[0020] This invention addresses the shortcomings of existing technologies by providing a method for preparing carbon sliders made from in-situ grown carbon nanotube-reinforced carbon fiber composites that requires no catalyst, has a simple preparation process, a short process flow, low cost, and is suitable for large-scale production.

[0021] This invention discloses an in-situ grown carbon nanotube-reinforced carbon fiber composite material carbon slider, which for the first time designs in-situ generated carbon nanotubes and carbon particles with a special distribution structure. This significantly improves the mechanical, electrical conductivity, and tribological properties of the slider; and through the in-situ growth characteristics of carbon nanotubes and carbon particles, it promotes the graphitization transformation of the densified asphalt under carbonization and graphitization, achieving a significant increase in the graphitization rate of the final product.

[0022] The present invention provides an in-situ grown carbon nanotube reinforced carbon fiber composite material carbon slide bar, comprising a carbon fiber needle-punched integral felt, a coating layer M covering the inside and outside of the carbon fiber needle-punched integral felt, and carbon coating on M.

[0023] The M includes the following four structures;

[0024] Structure M consists of carbon nanotubes and carbon particles generated in situ via chemical vapor deposition, with the carbon nanotubes and carbon particles distributed alternately.

[0025] Structure 2M consists of carbon nanotubes and carbon particles generated in situ by chemical vapor deposition, with the carbon particles coating the carbon nanotubes.

[0026] Structure 3M consists of a carbon nanotube layer and N generated in situ by chemical vapor deposition, wherein N is composed of in-situ generated carbon particles and carbon nanotubes; and N is coated on the carbon nanotubes.

[0027] Structure M consists of a carbon nanotube layer and N generated in situ by chemical vapor deposition, wherein N is composed of in situ generated carbon particles and carbon nanotubes; the carbon nanotube layer and N are alternately distributed.

[0028] The carbon coated on M is pyrolyzed carbon prepared by an impregnation and carbonization process; the carbon fiber needle-punched integral felt includes a carbon fiber braid and a conductive and wear-resistant filler.

[0029] The carbon fiber braid includes at least one of pure carbon fiber braid and a three-dimensional composite braid composed of carbon fiber and metal mesh.

[0030] The conductive wear-resistant filler includes graphite powder, and at least one of graphite powder and copper powder.

[0031] Preferably, no catalyst is required when preparing M.

[0032] In carbon fiber needle-punched monolithic felt, the particle size of graphite particles is 50-800μm, and the diameter of carbon fibers is 5-100μm.

[0033] In the coating layer M, the carbon particles A have a particle size of 20-600 nm.

[0034] In the coating layer M, the carbon nanotubes have a diameter of 5-30 nm and a length of 30 nm-3 μm.

[0035] In the coating layer M, the thickness of a single coating layer is less than or equal to 6 μm.

[0036] This invention discloses a method for preparing an in-situ grown carbon nanotube-reinforced pure carbon fiber slide bar, wherein the pure carbon fiber slide bar (i.e., the carbon slide bar does not contain metal) is prepared through the following steps:

[0037] Step 1

[0038] A series of materials are sequentially stacked: a single layer of 0° non-woven carbon cloth, a carbon fiber mesh, graphite powder, short carbon fibers (30-100mm long), a single layer of 90° non-woven carbon cloth, a carbon fiber mesh, graphite powder, and a single layer of 0° non-woven carbon cloth. Then, carbon fiber bundles are introduced perpendicular to the layup direction using a relay-style needle punching method to produce a product with a density of 0.2–0.8 g / cm³. 32.5D carbon fiber needle-punched integral felt;

[0039] Step Two

[0040] After fixing the carbon fiber needle-punched integral felt obtained in step one, it is placed in a heating furnace and subjected to pre-high temperature heat treatment at 1500-2100℃ under a protective atmosphere to obtain the integral felt after pre-high temperature heat treatment.

[0041] Step 3: Preparation of the M layer

[0042] The pre-high temperature heat-treated integral felt obtained in step two was subjected to repeated high and low temperature chemical vapor deposition to deposit carbon particle / carbon nanotube layers alternately on the surface of graphite particles, carbon fibers, etc., to obtain chemical vapor deposition pure carbon fiber slider.

[0043] Step 4: Asphalt Impregnation-Carbonization Treatment

[0044] The chemical vapor deposition pure carbon fiber slider obtained in step three is machined to the designed dimensions, with a machining allowance reserved, and then subjected to pitch impregnation-carbonization treatment until a density of 1.7–2.0 g / cm³ is obtained. 3 High-density impregnated and carbonized slip strip material;

[0045] Step 5

[0046] The impregnation-carbonization treated slider obtained in step four is subjected to a high-temperature graphitization treatment to obtain an in-situ grown carbon nanotube reinforced pure carbon fiber slider.

[0047] This invention discloses a method for preparing an in-situ grown carbon nanotube-reinforced metal-based carbon fiber composite material carbon slider, wherein the metal-based carbon fiber composite material carbon slider is prepared through the following steps:

[0048] Step A

[0049] A 2.5D carbon fiber composite needle-punched integral felt with a density of 0.6–2.6 g / cm3 is made by sequentially stacking single-layer 0° non-woven carbon cloth, carbon fiber mesh, graphite powder, copper material, single-layer 90° non-woven carbon cloth, carbon fiber mesh, graphite powder, copper material, and single-layer 0° non-woven carbon cloth. Then, carbon fiber bundles are introduced perpendicular to the layup direction using a relay needle-punching method.

[0050] Step B: Preparation of layer M

[0051] After fixing the carbon fiber composite needle-punched integral felt obtained in step one, it was placed in a heating furnace and subjected to repeated high and low temperature chemical vapor deposition. Carbon particle / carbon nanotube layers were alternately deposited on the surface of graphite particles, carbon fibers, etc., to obtain a chemical vapor deposition metal carbon fiber composite material slider with a density 1.5-2.2 times that of the integral felt in step A.

[0052] Step C: Asphalt Impregnation-Carbonization Treatment

[0053] The chemical vapor deposition pure carbon fiber slider obtained in step B is machined according to the design dimensions, and after leaving a machining allowance, it is subjected to asphalt impregnation-carbonization treatment until a high-density impregnated-carbonized in-situ grown carbon nanotube reinforced metal carbon fiber composite carbon slider with a density 1.02-1.15 times that obtained in step two is obtained.

[0054] This invention discloses a method for preparing carbon sliders made of in-situ grown carbon nanotubes reinforced with metal-type carbon fibers.

[0055] The copper material is selected from one of copper powder, copper mesh, and short copper wire. In the 2.5D carbon fiber needle-punched integral felt, the mass percentage of graphite powder is 1% to 10% and the mass percentage of copper material is 10% to 90%.

[0056] This invention discloses a method for preparing carbon sliders made of in-situ grown carbon nanotube-reinforced carbon fiber composite material. When preparing the M layer,

[0057] The in-situ chemical vapor deposition temperature is 850℃~1100℃;

[0058] The in-situ chemical vapor deposition time is 83–420 h;

[0059] The carbon source gas used is selected from at least one of propylene, natural gas, and methane.

[0060] The diluent gas used is selected from at least one of nitrogen and hydrogen.

[0061] The volume ratio of the carbon source gas to the diluent gas is 0.8-1.2:2.8-3.2.

[0062] This invention discloses a method for preparing carbon sliders made of in-situ grown carbon nanotube-reinforced carbon fiber composite material. The preparation of the M layer involves alternating in-situ vapor deposition at different temperatures, comprising the following steps:

[0063] (1) First, raise the temperature to 850-950℃ and keep it at that temperature for 3-20 hours.

[0064] (2) Reheat to 950–1050℃ and hold for 50–200 hours.

[0065] (3) Finally, raise the temperature to 1080~1100℃ and keep it warm for 30~200h.

[0066] This invention discloses a method for preparing carbon nanotube-reinforced pure carbon fiber carbon sliders.

[0067] In the pre-high temperature pretreatment of step two:

[0068] The protective atmosphere is selected from either argon or nitrogen atmosphere.

[0069] During the pre-high temperature treatment, the control time is 3-10 hours.

[0070] During the initial high-temperature treatment, the furnace pressure is controlled at 0.101-0.11 MPa;

[0071] In the post-high temperature pretreatment of step five:

[0072] The post-high-temperature graphitization treatment temperature is 2000-2400℃.

[0073] The post-high-temperature graphitization treatment time is 5–10 hours.

[0074] The protective atmosphere for the post-high-temperature graphitization treatment is selected from either argon or nitrogen atmosphere.

[0075] The pressure of the post-high temperature graphitization furnace is 0.12 MPa.

[0076] This invention discloses a method for preparing carbon slip strips made of in-situ grown carbon nanotube-reinforced carbon fiber composite material, wherein the asphalt impregnation-carbonization treatment includes the following steps:

[0077] After the M layer is prepared, the resulting sample is placed in an asphalt impregnation solution at 40-80℃ and impregnated under pressure for 1-3 hours. Then, the temperature is raised to 220-260℃ for curing for 2.5-3.5 hours, with an impregnation pressure of 1.5 MPa. After curing, carbonization is performed at 1000℃ for 40-60 hours per carbonization cycle, with a carbonization pressure of 0.1 MPa. This impregnation / curing / carbonization cycle is repeated until a density of 1.6–2.0 g / cm³ is obtained. 3 High-density C / C composite material; the polymer impregnation solution used in the polymer impregnation-carbonization treatment is an asphalt solution.

[0078] In this invention, carbon nanotubes are deposited in situ on the surface of carbon fibers using a simple in-situ chemical vapor deposition process without the use of a catalyst. Furthermore, carbon nanotubes can be deposited alternately on the surfaces of carbon fibers and graphite particles in situ by controlling the deposition temperature and time.

[0079] In this invention, the principle for generating carbon nanotubes and carbon particles is as follows: Low-temperature chemical vapor deposition (CVD) is used to form oxides from graphite and carbon fibers at low temperatures (oxygen originates from the raw materials used in the overall felt weaving process and from oxygen adsorption). These oxides then react at a CVD growth temperature of 850–950°C to form intermediate oxides. Nanowires are obtained through a disproportionation reaction; that is, the grown carbon nanotubes form only flocculent or clump-like structures, and the carbon atoms form only aggregates of short carbon nanowires. In this invention, the disproportionation reaction of oxides allows for the production of carbon nanowires / tubes without a catalyst. Further increasing the CVD reaction temperature to 950–1050°C results in filamentous carbon nanotubes that grow uniformly on the surface of graphite / silicon particles, with uniform diameters (around tens of nanometers). When the chemical vapor deposition (CVD) temperature reaches 1100℃, almost no carbon nanotubes grow; instead, amorphous carbon nanoparticles are deposited on the surfaces of graphite and carbon fibers (at 1070–1100℃, both graphite particles and short nanotubes are present, but the proportion of graphite particles is greater than that of short carbon nanotubes). By employing alternating high and low temperature deposition, carbon particles or carbon fibers can be formed with alternating carbon particle / carbon nanotube coatings. Compared to carbon nanotubes added externally during felt fabrication, this in-situ grown carbon nanotube not only effectively fixes itself to the surface of carbon fibers and graphite particles but also solves the problem of uneven carbon nanotube dispersion, fully realizing the excellent electrical and thermal conductivity, matrix strengthening, and improved wear resistance advantages of carbon nanotubes.

[0080] In this invention, the principle of achieving rapid carbonization or graphitization is as follows: After carbon nanotubes are grown in situ on the carbon surface inside the carbon fiber composite material, if furan resin is used for impregnation, due to the large amount of impregnation, it is difficult to completely carbonize it at 850℃. Graphitization can only be achieved through high-temperature graphitization. However, the decomposition and graphitization time of furan resin is longer than that of asphalt, so the degree of graphitization after high-temperature graphitization only reaches 87%. Moreover, furan resin is a thermosetting material and will not soften after heating, thus failing to achieve further densification of the carbon fibers during the carbonization and graphitization stages. If it is used to directly impregnate and carbonize to prepare metal-type carbon fiber composite carbon slide plates, the incomplete resin decomposition leads to poor conductivity and deteriorated friction performance of the slide plates. However, by using asphalt impregnation-carbonization at temperatures above 1000℃, rapid carbonization or graphitization can be achieved. After high-temperature graphitization treatment above 2000℃, the degree of graphitization can reach 93%. Furthermore, asphalt is a thermoplastic material and will soften after heating, achieving further densification of the carbon fibers during the carbonization and graphitization stages. If a metal-type carbon fiber composite carbon slide block is prepared by direct impregnation and carbonization with asphalt, the carbon conductivity and friction performance of the carbon slide block will be improved because the asphalt will completely decompose and carbonize at this temperature. The preparation process of this invention is simple, and the product exhibits superior mechanical, electrical, and frictional properties, making it suitable for large-scale industrial applications and production.

[0081] Without introducing metal, the product obtained by this invention has a flexural strength greater than 120 MPa, which can reach 130–145 MPa after optimization; a compressive strength of 370–390 MPa; and an impact toughness of 1.9–2.0 J·cm. -2 Its resistivity is as low as 16.8–17.1 μΩ·m, and its contact wire wear ratio is less than or equal to 0.008 mm. 2 / 10,000 frame cycles, the height wear ratio of the skateboard is less than or equal to 0.25mm / 10,000 vehicle-km, and the weight wear ratio of the skateboard is less than or equal to 25g / 10,000 vehicle-km.

[0082] When metallic Cu is introduced, the product obtained by this invention has a flexural strength greater than 135 MPa, which can be optimized to 138–152 MPa; a compressive strength of 290–295 MPa; and an impact toughness of 1.1–1.2 J·cm. -2 Its resistivity is as low as 2.5–2 μΩ·m, and its contact wire wear ratio is less than or equal to 0.018 mm. 2 / per 10,000 rides, the height wear ratio of the skateboard is less than or equal to 0.42mm / 10,000 rides, and the weight wear ratio of the skateboard is less than or equal to 31g / 10,000 rides. Attached Figure Description

[0083] Figure 1 A process flow diagram of the preparation method of pure carbon fiber slider with in-situ deposited carbon nanotubes provided in an embodiment of the present invention;

[0084] Figure 2 A process flow diagram of the preparation method of in-situ deposited carbon nanotubes metal-type carbon fiber composite carbon slider provided in an embodiment of the present invention;

[0085] Appendix Figure 3 The TEM morphology shows the in-situ deposited carbon nanotubes on the carbon fiber surface in Example 1 of this invention.

[0086] Depend on Figure 1 As can be seen, the present invention mainly includes key steps such as pre-heat treatment, high and low temperature alternating chemical vapor deposition, asphalt impregnation-carbonization, and post-heat treatment.

[0087] Depend on Figure 2 As can be seen, the present invention mainly includes key steps such as high and low temperature alternating chemical vapor deposition and asphalt impregnation-carbonization.

[0088] Depend on Figure 3 It can be seen that a large number of carbon nanotubes were deposited on the surface of the carbon fiber through alternating high and low temperature (1050~1100℃) chemical vapor deposition. Detailed Implementation

[0089] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the technical solutions recorded in the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0090] Comparative Example 1

[0091] A density of 0.35 g / cm³ was used. 3 The 2.5D carbon fiber needle-punched monolithic felt was used as a preform, and a density of 1.5 g / cm³ was prepared by chemical vapor deposition. 3 The C / C composite material, after undergoing a three-stage resin impregnation-carbonization process, yielded a product with a density of 1.8 g / cm³. 3 The C / C composite material was subjected to high-temperature heat treatment at 2300℃ and machining to obtain pure carbon fiber slide strips.

[0092] The pure carbon fiber slider in this comparative example was prepared mainly through the following steps:

[0093] (1) A mesh and non-woven fabric were made using PAN-type T700 (12K) carbon fiber produced by Toray Industries, Japan, ensuring a mass ratio of non-woven fabric to mesh of 8:2. A single layer of 0° non-woven fabric, a mesh layer, a 90° non-woven fabric, another mesh layer, and graphite (150μm, 10wt%) were sequentially stacked. Then, a relay-type needle-punching method was used to produce a density of 0.6 g / cm³. 3 Carbon fiber preforms.

[0094] (2) The preform was subjected to high-temperature heat treatment at 1600℃ under an argon protective atmosphere using graphite tooling. The whole process took 8 hours. The protective atmosphere was argon and the pressure was slightly positive (i.e. slightly exceeding the 0 mark of the vacuum pressure gauge).

[0095] (3) Using natural gas as the carbon source and hydrogen as the dilution gas, with a natural gas to hydrogen volume ratio of 1:3, pyrolytic carbon was deposited on the preform at 950℃ using thermal gradient chemical vapor deposition. After 100 hours of deposition, the C / C density was 0.85 g / cm³. 3 By rotating the C / C composite material 90° around its longitudinal centerline and then depositing it for 200 hours, a density of 1.5 g / cm³ was obtained. 3 C / C composite material.

[0096] (4) Using the designed graphite fixture, the C / C composite material was placed in a vacuum-pressure impregnation tank, with furan resin as the impregnating agent, and treated using a high-pressure impregnation process. Before impregnation, the sample was preheated to 60℃, with an impregnation pressure of 2MPa and a holding time of 1.5h. Afterward, the temperature was raised to 200℃ and held for approximately 3h for curing. After curing, the sample was transferred to a carbonization furnace for carbonization treatment at 850℃. After three cycles, the product density reached 1.8 g / cm³. 3 .

[0097] (5) The obtained product is placed in a high-temperature heat treatment furnace and treated at 2300℃ for 6 hours. Argon is used as the protective gas to obtain pure carbon fiber sliders. The specific properties are shown in Table 2 and Table 3.

[0098] The flexural strength, compressive strength, impact toughness, resistivity, and Shore hardness of carbon sliders made from pure carbon fibers and metal-based carbon nanotubes deposited by chemical vapor deposition and in-situ deposited carbon nanotubes were compared, and the results are shown in Table 2. Carbon fiber sliders made from both materials were then subjected to current-carrying friction with the CTMH150 contact line at a speed of 120 km / h, a current of 500 A, and a normal force of 70 N ± 10 N between the slider and the contact line. The tribological properties are shown in Table 3.

[0099] Comparative Example 2

[0100] A density of 0.35 g / cm³ was used. 3 A 2.5D carbon fiber needle-punched monolithic felt with incorporated carbon nanotubes was used as a preform, and a density of 1.5 g / cm³ was prepared by chemical vapor deposition. 3 The C / C composite material, after undergoing a three-stage resin impregnation-carbonization process, yielded a product with a density of 1.8 g / cm³. 3 The C / C composite material was subjected to high-temperature heat treatment at 2300℃ and machining to obtain pure carbon fiber slide strips.

[0101] The pure carbon fiber slider in this comparative example was prepared mainly through the following steps:

[0102] (1) A mesh and a non-woven fabric were made using PAN-type T700 (12K) carbon fiber produced by Toray Industries, Japan, ensuring a mass ratio of non-woven fabric to mesh of 8:2. A single layer of 0° non-woven fabric, a mesh layer, a 90° non-woven fabric, another mesh layer, graphite (150μm, 10wt%), and carbon nanotubes (20nm diameter, 10wt%) were sequentially stacked. Then, a relay-type needle punching method was used to produce a density of 0.35 g / cm³. 3 Carbon fiber preforms.

[0103] (2) The preform was subjected to high-temperature heat treatment at 1600℃ under an argon protective atmosphere using graphite tooling. The whole process took 8 hours. The protective atmosphere was argon and the pressure was slightly positive (i.e. slightly exceeding the 0 mark of the vacuum pressure gauge).

[0104] (3) Using natural gas as the carbon source and hydrogen as the dilution gas, with a natural gas to hydrogen volume ratio of 1:3, pyrolytic carbon was deposited on the preform at 950℃ using thermal gradient chemical vapor deposition. After 100 hours of deposition, the C / C density was 0.85 g / cm³. 3 By rotating the C / C composite material 90° around its longitudinal centerline and then depositing it for 200 hours, a density of 1.5 g / cm³ was obtained. 3 C / C composite material.

[0105] (4) Using the designed graphite fixture, the C / C composite material was placed in a vacuum-pressure impregnation tank, with furan resin as the impregnating agent, and treated using a high-pressure impregnation process. Before impregnation, the sample was preheated to 60℃, with an impregnation pressure of 2MPa and a holding time of 1.5h. Afterward, the temperature was raised to 200℃ and held for approximately 3h for curing. After curing, the sample was transferred to a carbonization furnace for carbonization treatment at 850℃. After three cycles, the product density reached 1.8 g / cm³. 3 .

[0106] (5) The obtained product is placed in a high-temperature heat treatment furnace and treated at 2300℃ for 6 hours. Argon is used as the protective gas to obtain pure carbon fiber sliders. The specific properties are shown in Table 2 and Table 3.

[0107] In the process of preparing carbon fiber preforms by relay needle punching, carbon nanotubes are difficult to disperse due to their small particle size, and many of them leak out from the felt.

[0108] Comparative Example 3

[0109] A density of 0.35 g / cm³ was used. 3 The 2.5D carbon fiber needle-punched monolithic felt was used as a preform, and a density of 1.5 g / cm³ was prepared by chemical vapor deposition. 3 The C / C composite material, after undergoing a three-stage pitch impregnation-carbonization process, yielded a density of 1.8 g / cm³. 3 The C / C composite material was subjected to high-temperature heat treatment at 2300℃ and machining to obtain pure carbon fiber slide strips.

[0110] The pure carbon fiber slider in this comparative example was prepared mainly through the following steps:

[0111] (1) A mesh and a non-woven fabric were made using PAN-type T700 (12K) carbon fiber produced by Toray Industries, Japan, ensuring a mass ratio of non-woven fabric to mesh of 8:2. A single layer of 0° non-woven fabric, a mesh layer, a 90° non-woven fabric, another mesh layer, graphite (150μm, 10wt%), and carbon nanotubes (20nm diameter, 10wt%) were sequentially stacked. Then, a relay-type needle punching method was used to produce a density of 0.35 g / cm³. 3 Carbon fiber preforms.

[0112] (2) The preform was subjected to high-temperature heat treatment at 1600℃ under an argon protective atmosphere using graphite tooling. The whole process took 8 hours. The protective atmosphere was argon and the pressure was slightly positive (i.e. slightly exceeding the 0 mark of the vacuum pressure gauge).

[0113] (3) Using natural gas as the carbon source and hydrogen as the dilution gas, with a natural gas to hydrogen volume ratio of 1:3, pyrolytic carbon was deposited on the preform at 950℃ using thermal gradient chemical vapor deposition. After 100 hours of deposition, the C / C density was 0.85 g / cm³. 3 By rotating the C / C composite material 90° around its longitudinal centerline and then depositing it for 200 hours, a density of 1.5 g / cm³ was obtained. 3 C / C composite material.

[0114] (4) Using the designed graphite fixture, the C / C composite material was placed in a vacuum-pressure impregnation tank, with asphalt as the impregnating agent, and treated using a high-pressure impregnation process. Before impregnation, the sample was preheated to 60℃, with an impregnation pressure of 2MPa and a holding time of 1.5h. Afterward, the temperature was raised to 250℃ and held for approximately 3h for curing. After curing, the sample was transferred to a carbonization furnace for carbonization treatment at 1000℃, with a single carbonization treatment time of 50h and a carbonization pressure of 0.1MPa. After three cycles of impregnation / curing / carbonization treatment, the product density reached 1.8g / cm³. 3 .

[0115] (5) The obtained product is placed in a high-temperature heat treatment furnace and treated at 2300℃ for 6 hours. Argon is used as the protective gas to obtain pure carbon fiber sliders. The specific properties are shown in Table 2 and Table 3.

[0116] Comparative Example 4

[0117] A density of 0.35 g / cm³ was used. 3 A 2.5D carbon fiber needle-punched monolithic felt with incorporated carbon nanotubes was used as a preform, and a density of 1.5 g / cm³ was prepared by chemical vapor deposition. 3 The C / C composite material, after undergoing two pitch impregnation-carbonization processes, yielded a density of 1.8 g / cm³. 3The C / C composite material was subjected to high-temperature heat treatment at 2300℃ and machining to obtain pure carbon fiber slide strips.

[0118] The pure carbon fiber slider in this comparative example was prepared mainly through the following steps:

[0119] (1) A mesh and a non-woven fabric were made using PAN-type T700 (12K) carbon fiber produced by Toray Industries, Japan, ensuring a mass ratio of non-woven fabric to mesh of 8:2. A single layer of 0° non-woven fabric, a mesh layer, a 90° non-woven fabric, another mesh layer, graphite (150μm, 10wt%), and carbon nanotubes (20nm diameter, 10wt%) were sequentially stacked. Then, a relay-type needle punching method was used to produce a density of 0.35 g / cm³. 3 Carbon fiber preforms.

[0120] (2) The preform was subjected to high-temperature heat treatment at 1600℃ under an argon protective atmosphere using graphite tooling. The whole process took 8 hours. The protective atmosphere was argon and the pressure was slightly positive (i.e. slightly exceeding the 0 mark of the vacuum pressure gauge).

[0121] (3) Using natural gas as the carbon source and hydrogen as the dilution gas, with a natural gas to hydrogen volume ratio of 1:3, pyrolytic carbon was deposited on the preform at 950℃ using thermal gradient chemical vapor deposition. After 100 hours of deposition, the C / C density was 0.85 g / cm³. 3 By rotating the C / C composite material 90° around its longitudinal centerline and then depositing it for 200 hours, a density of 1.5 g / cm³ was obtained. 3 C / C composite material.

[0122] (4) Using the designed graphite fixture, the C / C composite material was placed in a vacuum-pressure impregnation tank, with asphalt as the impregnating agent, and treated using a high-pressure impregnation process. Before impregnation, the sample was preheated to 60℃, with an impregnation pressure of 2MPa and a holding time of 1.5h. Afterward, the temperature was raised to 250℃ and held for approximately 3h for curing. After curing, the sample was transferred to a carbonization furnace for carbonization treatment at 1000℃, with a single carbonization treatment time of 55h and a carbonization pressure of 0.1MPa. After two cycles of impregnation / curing / carbonization treatment, the product density reached 1.8g / cm³. 3 .

[0123] (5) The obtained product is placed in a high-temperature heat treatment furnace and treated at 2300℃ for 6 hours. Argon is used as the protective gas to obtain pure carbon fiber sliders. The specific properties are shown in Table 2 and Table 3.

[0124] In the process of preparing carbon fiber preforms by relay needle punching, carbon nanotubes are difficult to disperse due to their small particle size, and many of them leak out from the felt.

[0125] Comparative Example 5

[0126] Using a density of 0.6 g / cm³ 3 Using 2.5D carbon fiber copper mesh needle-punched integral felt as a preform, metal-type carbon fiber composite carbon slip strips were prepared through chemical vapor deposition and three-stage resin impregnation-carbonization processes.

[0127] The metal-type carbon fiber composite material carbon slider in this comparative example is mainly prepared through the following steps:

[0128] (1) First, a PAN-type T700 (12K) carbon fiber bundle manufactured by Toray Industries, Japan, is woven into a non-woven fabric. Another portion of the T700 carbon fiber bundle is cut into short fibers of 30-100mm in length and dispersed together with copper powder and graphite powder to form a mesh. Second, 0° non-woven carbon fabric, carbon fiber mesh, copper mesh, 90° non-woven carbon fabric, carbon fiber mesh, copper mesh, and 0° non-woven carbon fabric are sequentially stacked. Copper wire and / or carbon fiber bundles are introduced perpendicular to the layup direction using a relay-style needle punching method to produce a non-woven fabric with a volume content of 5-15%, a mesh with a volume content of 5-15%, and a copper mesh and / or copper wire with a volume content of 5-30% and a density of 0.6g / cm³. 3 Composite felt.

[0129] (2) Using propylene as the carbon source gas and hydrogen as the dilution gas, with a volume ratio of natural gas to hydrogen of 1:2, the preform was deposited with pyrolytic carbon at 1000℃ using thermal gradient chemical vapor deposition. After 120h of deposition, the material was rotated 90° with the center line of the length direction as the axis, and then deposited for another 250h to obtain the C / Cu composite material.

[0130] (3) The designed graphite fixture was used to place the C / Cu composite material into a vacuum-pressure impregnation tank, using furan resin as the impregnating agent and a high-pressure impregnation process. Before impregnation, the sample was preheated to 100℃, with an impregnation pressure of 2MPa and a holding time of 2h. Afterward, the temperature was raised to 200℃ and held for approximately 5h for curing. After curing, the sample was transferred to a carbonization furnace for carbonization at 850℃ for 60h. After three cycles, a density of 2.0-4.0 g / cm³ was obtained. 3 The specific properties of the metal-type carbon fiber composite material carbon slider are shown in Tables 2 and 3.

[0131] Comparative Example 6

[0132] Using a density of 0.7 g / cm³ 3 Using 2.5D carbon fiber copper mesh needle-punched integral felt with added carbon nanotubes as a preform, a metal-type carbon fiber composite carbon slip strip was prepared by chemical vapor deposition and three resin impregnation-carbonization processes.

[0133] The metal-type carbon fiber composite material carbon slider in this comparative example is mainly prepared through the following steps:

[0134] (1) First, a PAN-type T700 (12K) carbon fiber bundle manufactured by Toray Industries, Japan, is woven into a non-woven fabric. Another portion of the T700 carbon fiber bundle is cut into short fibers of 30-100 mm in length and dispersed together with copper wire (10 μm in diameter), graphite powder (150 μm), and carbon nanotubes (20 nm in diameter) to form a mesh. Second, 0° non-woven carbon fabric, carbon fiber mesh, copper mesh, 90° non-woven carbon fabric, carbon fiber mesh, copper mesh, and 0° non-woven carbon fabric are sequentially stacked. Copper wire and / or carbon fiber bundles are introduced perpendicular to the layup direction using a relay-type needle punching method to produce a non-woven fabric with a volume content of 5-15%, a mesh with a volume content of 5-15%, and a copper mesh and / or copper wire with a volume content of 5-30% and a density of 0.7 g / cm³. 3 Composite felt.

[0135] (2) Using propylene as the carbon source gas and hydrogen as the dilution gas, with a volume ratio of natural gas to hydrogen of 1:2, the preform was deposited with pyrolytic carbon at 1000℃ using thermal gradient chemical vapor deposition. After 120h of deposition, the material was rotated 90° with the center line of the length direction as the axis, and then deposited for another 230h to obtain the C / Cu composite material.

[0136] (3) The designed graphite fixture was used to place the C / Cu composite material into a vacuum-pressure impregnation tank, using furan resin as the impregnating agent and a high-pressure impregnation process. Before impregnation, the sample was preheated to 100℃, with an impregnation pressure of 2MPa and a holding time of 2h. Afterward, the temperature was raised to 200℃ and held for approximately 5h for curing. After curing, the sample was transferred to a carbonization furnace for carbonization at 850℃ for 60h. After three cycles, a density of 2.0-4.0 g / cm³ was obtained. 3 The specific properties of the metal-type carbon fiber composite material carbon slider are shown in Tables 2 and 3.

[0137] In the process of preparing carbon fiber preforms by relay needle punching, carbon nanotubes are difficult to disperse due to their small particle size, and many of them leak out from the felt.

[0138] Comparative Example 7

[0139] Using a density of 0.6 g / cm³ 3 Using 2.5D carbon fiber copper mesh needle-punched integral felt as a preform, metal-type carbon fiber composite carbon slip strips were prepared through chemical vapor deposition and two pitch impregnation-carbonization processes.

[0140] The metal-type carbon fiber composite material carbon slider in this comparative example is mainly prepared through the following steps:

[0141] (1) First, a PAN-type T700 (12K) carbon fiber bundle manufactured by Toray Industries, Japan, is woven into a non-woven fabric. Another portion of the T700 carbon fiber bundle is cut into short fibers of 30-100mm in length and dispersed together with copper powder and graphite powder to form a mesh. Second, 0° non-woven carbon fabric, carbon fiber mesh, copper mesh, 90° non-woven carbon fabric, carbon fiber mesh, copper mesh, and 0° non-woven carbon fabric are sequentially stacked. Copper wire and / or carbon fiber bundles are introduced perpendicular to the layup direction using a relay-style needle punching method to produce a non-woven fabric with a volume content of 5-15%, a mesh with a volume content of 5-15%, and a copper mesh and / or copper wire with a volume content of 5-30% and a density of 0.6g / cm³. 3 Composite felt.

[0142] (2) Using propylene as the carbon source gas and hydrogen as the dilution gas, with a volume ratio of natural gas to hydrogen of 1:2, the preform was deposited with pyrolytic carbon at 1000℃ using thermal gradient chemical vapor deposition. After 120h of deposition, the material was rotated 90° with the center line of the length direction as the axis, and then deposited for another 250h to obtain the C / Cu composite material.

[0143] (3) Using the designed graphite fixture, the C / Cu composite material was placed in a vacuum-pressure impregnation tank, with asphalt as the impregnating agent, and treated using a high-pressure impregnation process. Before impregnation, the sample was preheated to 60℃, with an impregnation pressure of 2MPa and a holding time of 1.5h. Afterward, the temperature was raised to 250℃ and held for approximately 3h for curing. After curing, the sample was transferred to a carbonization furnace for carbonization treatment at 1000℃, with a single carbonization treatment time of 40-60h and a carbonization pressure of 0.1MPa. After two cycles of impregnation / curing / carbonization treatment, a density of 2.0-4.0 g / cm³ was obtained. 3 The specific properties of the metal-type carbon fiber composite material carbon slider are shown in Tables 2 and 3.

[0144] Comparative Example 8

[0145] Using a density of 0.7 g / cm³ 3 Using 2.5D carbon fiber copper mesh needle-punched integral felt with added carbon nanotubes as a preform, a metal-type carbon fiber composite carbon slip strip was prepared by chemical vapor deposition and three-stage pitch impregnation-carbonization process.

[0146] The metal-type carbon fiber composite material carbon slider in this comparative example is mainly prepared through the following steps:

[0147] (2) First, a PAN-type T700 (12K) carbon fiber bundle manufactured by Toray Industries, Japan, is woven into a non-woven fabric. Another portion of the T700 carbon fiber bundle is cut into short fibers of 30-100 mm in length and dispersed together with copper wire (10 μm in diameter), graphite powder (150 μm), and carbon nanotubes (20 nm in diameter) to form a mesh. Second, 0° non-woven carbon fabric, carbon fiber mesh, copper mesh, 90° non-woven carbon fabric, carbon fiber mesh, copper mesh, and 0° non-woven carbon fabric are sequentially stacked. Copper wire and / or carbon fiber bundles are introduced perpendicular to the layup direction using a relay-style needle punching method to produce a non-woven fabric with a volume content of 5-15%, a mesh with a volume content of 5-15%, and a copper mesh and / or copper wire with a volume content of 5-30% and a density of 0.7 g / cm³. 3 Composite felt.

[0148] (2) Using propylene as the carbon source gas and hydrogen as the dilution gas, with a volume ratio of natural gas to hydrogen of 1:2, the preform was deposited with pyrolytic carbon at 1000℃ using thermal gradient chemical vapor deposition. After 120h of deposition, the material was rotated 90° with the center line of the length direction as the axis, and then deposited for another 230h to obtain the C / Cu composite material.

[0149] (3) Using the designed graphite fixture, the C / Cu composite material was placed in a vacuum-pressure impregnation tank, with asphalt as the impregnating agent, and treated using a high-pressure impregnation process. Before impregnation, the sample was preheated to 60℃, with an impregnation pressure of 2MPa and a holding time of 1.5h. Afterward, the temperature was raised to 250℃ and held for approximately 3h for curing. After curing, the sample was transferred to a carbonization furnace for carbonization treatment at 1000℃, with a single carbonization treatment time of 40-60h and a carbonization pressure of 0.1MPa. After three cycles of impregnation / curing / carbonization treatment, a density of 2.0-4.0 g / cm³ was obtained. 3 The specific properties of the metal-type carbon fiber composite material carbon slider are shown in Tables 2 and 3.

[0150] In the process of preparing carbon fiber preforms by relay needle punching, carbon nanotubes are difficult to disperse due to their small particle size, and many of them leak out from the felt.

[0151] Example 1:

[0152] A density of 0.35 g / cm³ was used. 3 The fiber needle-punched monolithic felt was a preform, and a density of 1.6 g / cm³ was prepared by chemical vapor deposition. 3 The C / C composite material, after undergoing a three-stage pitch impregnation-carbonization process, yielded a density of 1.9 g / cm³. 3 The C / C composite material was subjected to high-temperature heat treatment at 2300℃ and machining to obtain pure carbon fiber slide strips.

[0153] The pure carbon fiber slider in this embodiment is mainly prepared through the following steps:

[0154] (1) PAN-type T700 (12K) carbon fiber manufactured by Toray Industries, Japan, was used to make a mesh and a non-woven fabric, ensuring a mass ratio of non-woven fabric to mesh of 8:2. A single layer of 0° non-woven fabric, a mesh layer, a 90° non-woven fabric, another mesh layer, and graphite (150μm, 10wt%) were sequentially stacked. Then, a relay-type needle-punching method was used to produce a density of 0.35 g / cm³. 3 Carbon fiber preforms.

[0155] (2) The preform was subjected to high-temperature heat treatment at 1600℃ under an argon protective atmosphere using the designed graphite tooling. The whole process took 8 hours. The protective atmosphere was argon and the pressure was slightly positive (i.e. slightly exceeding the 0 mark of the vacuum pressure gauge).

[0156] (3) Using natural gas as the carbon source and hydrogen as the dilution gas, with a volume ratio of natural gas to hydrogen of 1:3, pyrolytic carbon was deposited on the preform at 850℃ using alternating chemical vapor deposition. After 4 hours of deposition, the C / C composite material was rotated 90° around the centerline of the length direction, and deposition continued for another 4 hours. Then, the temperature was increased to 1020℃ at a rate of 10℃ / min, and deposition continued for 50 hours. The C / C composite material was rotated 90° around the centerline of the length direction, and deposition continued for another 50 hours. Finally, the temperature was increased to 1080℃ at a rate of 10℃ / min, and deposition continued for 100 hours. The C / C composite material was rotated 90° around the centerline of the length direction, and deposition continued for another 100 hours, resulting in a density of 1.6 g / cm³. 3 C / C composite material.

[0157] (4) Using the designed graphite fixture, the C / C composite material was placed in a vacuum-pressure impregnation tank, with asphalt as the impregnating agent, and treated using a high-pressure impregnation process. Before impregnation, the sample was preheated to 60℃, with an impregnation pressure of 2MPa and a holding time of 1.5h. Afterward, the temperature was raised to 250℃ and held for approximately 3h for curing. After curing, the sample was transferred to a carbonization furnace for carbonization treatment at 1000℃, with a single carbonization treatment time of 40-60h and a carbonization pressure of 0.1MPa. After two cycles of impregnation / curing / carbonization treatment, the product density reached 1.85g / cm³. 3 .

[0158] (5) The obtained product was placed in a high-temperature heat treatment furnace and heat-treated at 2300℃ for 6 hours. Argon was used as the protective gas to obtain in-situ generated carbon nanotube pure carbon fiber slider. The specific properties are shown in Table 2 and Table 3.

[0159] Example 2:

[0160] A density of 0.4 g / cm³ was used.3 The fiber needle-punched monolithic felt was a preform, and a density of 1.6 g / cm³ was prepared by chemical vapor deposition. 3 The C / C composite material, after undergoing a three-stage pitch impregnation-carbonization process, yielded a density of 1.9 g / cm³. 3 The C / C composite material was subjected to high-temperature heat treatment at 2300℃ and machining to obtain pure carbon fiber slide strips.

[0161] The pure carbon fiber slider in this embodiment is mainly prepared through the following steps:

[0162] (1) PAN-type T700 (12K) carbon fiber manufactured by Toray Industries, Japan, was used to make a mesh and a non-woven fabric, ensuring a mass ratio of non-woven fabric to mesh of 8:2. A single layer of 0° non-woven fabric, a mesh layer, a 90° non-woven fabric, another mesh layer, and graphite (150μm, 10wt%) were sequentially stacked. Then, a relay-type needle-punching method was used to produce a density of 0.4 g / cm³. 3 Carbon fiber preforms.

[0163] (2) The preform was subjected to high-temperature heat treatment at 1600℃ under an argon protective atmosphere using the designed graphite tooling. The whole process took 8 hours. The protective atmosphere was argon and the pressure was slightly positive (i.e. slightly exceeding the 0 mark of the vacuum pressure gauge).

[0164] (3) Using natural gas as the carbon source and hydrogen as the dilution gas, with a volume ratio of natural gas to hydrogen of 1:3, pyrolytic carbon was deposited on the preform at 850℃ using alternating chemical vapor deposition. After 4 hours of deposition, the C / C composite material was rotated 90° around the centerline of the length direction, and deposition continued for another 4 hours. Then, the temperature was increased to 950℃ at a rate of 10℃ / min, and deposition continued for 60 hours. The C / C composite material was rotated 90° around the centerline of the length direction, and deposition continued for another 60 hours. Finally, the temperature was increased to 1100℃ at a rate of 10℃ / min, and deposition continued for 100 hours. The C / C composite material was rotated 90° around the centerline of the length direction, and deposition continued for another 100 hours, resulting in a density of 1.6 g / cm³. 3 C / C composite material.

[0165] (4) Using the designed graphite fixture, the C / C composite material was placed in a vacuum-pressure impregnation tank, with asphalt as the impregnating agent, and treated using a high-pressure impregnation process. Before impregnation, the sample was preheated to 60℃, with an impregnation pressure of 2MPa and a holding time of 1.5h. Afterward, the temperature was raised to 250℃ and held for approximately 3h for curing. After curing, the sample was transferred to a carbonization furnace for carbonization treatment at 1000℃, with a single carbonization treatment time of 40-60h and a carbonization pressure of 0.1MPa. After three cycles of impregnation / curing / carbonization treatment, the product density reached 1.85g / cm³. 3.

[0166] (5) The obtained product was placed in a high-temperature heat treatment furnace and heat-treated at 2300℃ for 6 hours. Argon was used as the protective gas to obtain in-situ generated carbon nanotube pure carbon fiber slider. The specific properties are shown in Table 2 and Table 3.

[0167] Example 3:

[0168] Using a density of 0.6 g / cm³ 3 Using 2.5D carbon fiber copper mesh needle-punched integral felt as a preform, metal-type carbon fiber composite carbon slip strips were prepared through chemical vapor deposition and two pitch impregnation-carbonization processes.

[0169] The metal-type carbon fiber composite material carbon slider in this embodiment is mainly prepared through the following steps:

[0170] (1) First, a PAN-type T700 (12K) carbon fiber bundle manufactured by Toray Industries, Japan, is woven into a non-woven fabric. Another portion of the T700 carbon fiber bundle is cut into short fibers of 30-100mm in length and dispersed together with copper powder and graphite powder to form a mesh. Second, 0° non-woven carbon fabric, carbon fiber mesh, copper mesh, 90° non-woven carbon fabric, carbon fiber mesh, copper mesh, and 0° non-woven carbon fabric are sequentially stacked. Copper wire and / or carbon fiber bundles are introduced perpendicular to the layup direction using a relay-style needle punching method to produce a non-woven fabric with a volume content of 5-15%, a mesh with a volume content of 5-15%, and a copper mesh and / or copper wire with a volume content of 5-30% and a density of 0.6g / cm³. 3 Composite felt.

[0171] (2) Using natural gas as the carbon source and hydrogen as the dilution gas, with a volume ratio of natural gas to hydrogen of 1:3, pyrolytic carbon was deposited on the preform at 850℃ using alternating chemical vapor deposition (CVD). After 4 hours of deposition, the C / Cu composite material was rotated 90° around the centerline along the length direction, and deposition continued for another 4 hours. The temperature was then increased to 1020℃ at a rate of 10℃ / min, and deposition continued for 50 hours. The C / Cu composite material was then rotated 90° around the centerline along the length direction, and deposition continued for another 50 hours. Finally, the temperature was increased to 1080℃ at a rate of 10℃ / min, and deposition continued for 100 hours. The C / Cu composite material was then rotated 90° around the centerline along the length direction, and deposition continued for another 100 hours, yielding a material with a density of 1.6 g / cm³. 3 C / C composite material.

[0172] (4) Using the designed graphite fixture, the C / Cu composite material was placed in a vacuum-pressure impregnation tank, with asphalt as the impregnating agent, and treated using a high-pressure impregnation process. Before impregnation, the sample was preheated to 60℃, with an impregnation pressure of 2MPa and a holding time of 1.5h. Afterward, the temperature was raised to 250℃ and held for approximately 3h for curing. After curing, the sample was transferred to a carbonization furnace for carbonization treatment at 1000℃. The carbonization time for each treatment was 40-60h, and the carbonization pressure was 0.1MPa. After two cycles of impregnation / curing / carbonization, the product density reached 2.0-4.0 g / cm³. 3 For specific performance details, please refer to Tables 2 and 3.

[0173] Example 4:

[0174] Using a density of 1.0 g / cm³ 3 Using 2.5D carbon fiber copper mesh needle-punched integral felt as a preform, metal-type carbon fiber composite carbon slip strips were prepared through chemical vapor deposition and three-stage pitch impregnation-carbonization processes.

[0175] The metal-type carbon fiber composite material carbon slider in this embodiment is mainly prepared through the following steps:

[0176] (1) First, a PAN-type T700 (12K) carbon fiber bundle manufactured by Toray Industries, Japan, is woven into a non-woven fabric. Another portion of the T700 carbon fiber bundle is cut into short fibers of 30-100mm in length and dispersed together with copper powder and graphite powder to form a mesh. Second, 0° non-woven carbon fabric, carbon fiber mesh, copper mesh, 90° non-woven carbon fabric, carbon fiber mesh, copper mesh, and 0° non-woven carbon fabric are sequentially stacked. Copper wire and / or carbon fiber bundles are introduced perpendicular to the layup direction using a relay-style needle punching method to produce a non-woven fabric with a volume content of 5-15%, a mesh with a volume content of 5-15%, and a copper mesh and / or copper wire with a volume content of 5-30% and a density of 1.0 g / cm³. 3 Composite felt.

[0177] (2) Using natural gas as the carbon source and hydrogen as the dilution gas, with a volume ratio of natural gas to hydrogen of 1:3, pyrolytic carbon was deposited on the preform at 850℃ using alternating chemical vapor deposition (CVD). After 4 hours of deposition, the C / Cu composite material was rotated 90° around its length centerline, and deposition continued for another 4 hours. The temperature was then increased to 950℃ at a rate of 10℃ / min, and deposition continued for 60 hours. The C / Cu composite material was then rotated 90° around its length centerline, and deposition continued for another 60 hours. Finally, the temperature was increased to 1100℃ at a rate of 10℃ / min, and deposition continued for 100 hours. The C / Cu composite material was then rotated 90° around its length centerline, and deposition continued for another 100 hours, yielding a preform with a density of 2.0 g / cm³. 3 C / Cu composite material.

[0178] (3) Using the designed graphite fixture, the C / Cu composite material was placed in a vacuum-pressure impregnation tank, with asphalt as the impregnating agent, and treated using a high-pressure impregnation process. Before impregnation, the sample was preheated to 60℃, with an impregnation pressure of 2MPa and a holding time of 1.5h. Afterward, the temperature was raised to 250℃ and held for approximately 3h for curing. After curing, the sample was transferred to a carbonization furnace for carbonization treatment at 1000℃, with a single carbonization treatment time of 40-60h and a carbonization pressure of 0.1MPa. After three cycles of impregnation / curing / carbonization treatment, a density of 2.8 g / cm³ was obtained. 3 The specific properties of the metal-type carbon fiber composite material carbon slider are shown in Tables 2 and 3.

[0179] As shown in Tables 2 and 3, compared with the pure carbon fiber sliders prepared by the conventional process in Comparative Examples 1-4, the graphitization degree, mechanical properties, electrical conductivity, and electric tribological wear performance of the pure carbon fiber sliders with in-situ grown carbon nanotubes in Examples 1 and 2 are significantly improved. Compared with the metal-type carbon fiber sliders prepared by the conventional process in Comparative Examples 5-8, the graphitization degree, mechanical properties, electrical conductivity, and electric tribological wear performance of the metal-type carbon fiber sliders with in-situ grown carbon nanotubes in Examples 3 and 4 are also significantly improved. Furthermore, because the pure carbon fiber sliders with in-situ grown carbon nanotubes underwent a high-temperature graphitization treatment of 1000℃ pitch carbonization to above 2000℃, while the metal-type carbon fiber sliders with in-situ grown carbon nanotubes only underwent a 1000℃ pitch carbonization treatment, the graphitization degree of the pure carbon fiber sliders with in-situ grown carbon nanotubes is much higher than that of the metal-type carbon fiber sliders with in-situ grown carbon nanotubes.

[0180] Table 2 Mechanical and electrical properties of carbon fiber sliders

[0181]

[0182] Table 3. Friction and Wear Properties of Carbon Fiber Sliding Strips

[0183]

[0184]

Claims

1. A carbon slider made of in-situ grown carbon nanotubes reinforced carbon fiber composite material, characterized in that: The carbon slide bar includes a carbon fiber needle-punched integral felt, a covering layer M covering the inside and outside of the carbon fiber needle-punched integral felt, and carbon covering M. The M includes the following four structures; Structure M consists of carbon nanotubes and carbon particles generated in situ via chemical vapor deposition, with the carbon nanotubes and carbon particles distributed alternately. Structure 2M consists of carbon nanotubes and carbon particles generated in situ by chemical vapor deposition, with the carbon particles coating the carbon nanotubes. Structure 3M consists of a carbon nanotube layer and N generated in situ by chemical vapor deposition, wherein N is composed of in-situ generated carbon particles and carbon nanotubes; and N is coated on the carbon nanotubes. Structure M consists of a carbon nanotube layer and N generated in situ by chemical vapor deposition, wherein N is composed of in situ generated carbon particles and carbon nanotubes; the carbon nanotube layer and N are alternately distributed. The carbon coated on M is pyrolyzed carbon prepared by an impregnation and carbonization process; the carbon fiber needle-punched integral felt includes a carbon fiber braid and a conductive and wear-resistant filler. The carbon fiber braid includes at least one of pure carbon fiber braid and a three-dimensional composite braid composed of carbon fiber and metal mesh. The conductive wear-resistant filler includes graphite powder, and at least one of graphite powder and copper powder. No catalyst was used in the preparation of M; The preparation of layer M involves in-situ vapor deposition at different temperatures, including the following steps: (1) First, raise the temperature to 850~950℃ and keep it warm for 3~20 hours. (2) Reheat to 950~1050℃ and hold for 50~200h. (3) Finally, raise the temperature to 1080~1100℃ and keep it warm for 30~200h; The carbon source gas used is selected from at least one of propylene, natural gas, and methane. The diluent gas used is selected from at least one of nitrogen and hydrogen. The volume ratio of the carbon source gas to the diluent gas is 0.8-1.2:2.8-3.

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2. The carbon slider of in-situ grown carbon nanotube reinforced carbon fiber composite material according to claim 1, characterized in that: In carbon fiber needle-punched monolithic felt, the particle size of graphite powder is 50-800μm, and the diameter of carbon fiber is 5~100μm.

3. The carbon slider of in-situ grown carbon nanotube reinforced carbon fiber composite material according to claim 1, characterized in that: In the coating layer M, the carbon particles have a particle size of 20-600 nm; In the coating layer M, the carbon nanotubes have a diameter of 5-30 nm and a length of 30 nm-3 μm; In the coating layer M, the thickness of a single coating layer is less than or equal to 6 μm.

4. The carbon slider of in-situ grown carbon nanotube reinforced carbon fiber composite material according to claim 1, characterized in that: When the carbon slider does not contain metal, its preparation method includes the following steps: Step 1 A series of materials are sequentially stacked: a single layer of 0° non-woven carbon cloth, a carbon fiber mesh, graphite powder, short carbon fibers, a single layer of 90° non-woven carbon cloth, a carbon fiber mesh, graphite powder, and a single layer of 0° non-woven carbon cloth. Then, a relay-style needle-punching method is used to introduce carbon fiber bundles perpendicular to the layup direction, resulting in a density of 0.2–0.8 g / cm³. 3 2.5D carbon fiber needle-punched integral felt; the short carbon fibers are 30-100 mm in length; Step Two After fixing the carbon fiber needle-punched integral felt obtained in step one, it is placed in a heating furnace and subjected to pre-high temperature heat treatment at 1500~2100℃ under a protective atmosphere to obtain the integral felt after pre-high temperature heat treatment. Step 3: Preparation of the M layer Chemical vapor deposition was performed on the pre-high temperature heat-treated integral felt obtained in step two to deposit carbon particle / carbon nanotube layers on the graphite powder particles and carbon fiber surfaces, resulting in chemical vapor deposition pure carbon fiber slider. Step 4: Asphalt Impregnation-Carbonization Treatment The chemical vapor deposition pure carbon fiber slider obtained in step three is machined to the designed dimensions, with a machining allowance reserved, and then subjected to pitch impregnation-carbonization treatment until a density of 1.7~2.0 g / cm³ is obtained. 3 High-density impregnated-carbonized slip strip material; Step 5 The impregnation-carbonization treated slider material obtained in step four is subjected to high-temperature graphitization treatment to obtain in-situ grown carbon nanotube reinforced pure carbon fiber slider. When the carbon slider contains metal, its preparation method includes the following steps: Step A A series of materials are sequentially stacked: single-layer 0° non-woven carbon cloth, carbon fiber mesh, graphite powder, copper material, single-layer 90° non-woven carbon cloth, carbon fiber mesh, graphite powder, copper material, and single-layer 0° non-woven carbon cloth. Then, a relay-style needle-punching method is used to introduce carbon fiber bundles perpendicular to the layup direction to create a density of 0.6–2.6 g / cm³. 3 2.5D carbon fiber composite needle-punched integral felt; Step B: Prepare layer M After fixing the carbon fiber composite needle-punched monolithic felt obtained in step A, it is placed in a heating furnace for chemical vapor deposition to deposit carbon particle / carbon nanotube layers on the graphite powder particles and carbon fiber surface, resulting in a chemical vapor deposition metal-type carbon fiber composite material slider with a density 1.5-2.2 times that of the monolithic felt in step A. Step C: Asphalt impregnation-carbonization treatment The chemical vapor deposition metal-type carbon fiber composite slide obtained in step B is machined according to the design dimensions, and after leaving a machining allowance, it is subjected to asphalt impregnation-carbonization treatment until a high-density impregnation-carbonization treatment and in-situ grown carbon nanotube reinforced metal-type carbon fiber composite slide with a density 1.02-1.15 times that of the one obtained in step B is obtained.

5. The carbon slider of in-situ grown carbon nanotube reinforced carbon fiber composite material according to claim 4, characterized in that: In the 2.5D carbon fiber needle-punched integral felt, the mass percentage of graphite powder is 1% to 10%; in the 2.5D carbon fiber composite needle-punched integral felt, the copper material is selected from one of copper powder, copper mesh, and short copper wire, and the mass percentage of graphite powder is 1% to 10% and the mass percentage of copper material is 10% to 90%.

6. The carbon slider of in-situ grown carbon nanotube reinforced carbon fiber composite material according to claim 4, characterized in that: The protective atmosphere is selected from either argon or nitrogen atmosphere. During the aforementioned high-temperature heat treatment, the control time is 3-10 hours. During the initial high-temperature heat treatment, the furnace pressure is controlled at 0.101-0.11 MPa; In the post-high temperature graphitization treatment: The post-high temperature graphitization treatment temperature is 2000-2400 ℃. The post-high-temperature graphitization treatment time is 5~10 hours. The protective atmosphere for the post-high-temperature graphitization treatment is selected from either argon or nitrogen atmosphere. The pressure of the post-high temperature graphitization furnace is 0.12 MPa.

7. The carbon slider of in-situ grown carbon nanotube reinforced carbon fiber composite material according to claim 4, characterized in that: The asphalt impregnation-carbonization treatment includes the following steps; After the M layer is prepared, the resulting sample is placed in an asphalt impregnation solution at 40-80℃ and impregnated under pressure for 1-3 hours. Then, the temperature is raised to 220-260℃ for curing for 2.5-3.5 hours, with an impregnation pressure of 1.5 MPa. After curing, carbonization is performed at 1000℃ for 40-60 hours per carbonization cycle, with a carbonization pressure of 0.1 MPa. This process is repeated until the density reaches 1.6-2.0 g / cm³. 3 .

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