Method for producing a composite carbon fiber material, composite carbon fiber material and use

Abstract

The application relates to the technical field of carbon fiber composite materials, and discloses a method for preparing a composite carbon fiber material, the composite carbon fiber material and application. The method comprises the following steps: impregnating carbon fibers with an organic silicon dispersion liquid, and then solidifying and heat-treating the carbon fibers to obtain the composite carbon fiber material; wherein the organic silicon dispersion liquid contains an organic silicon polymer and reinforcing particles; the reinforcing particles are selected from at least one of silicon dioxide, silicon carbide, boron carbide, graphite and boron nitride. The method can improve the film-forming performance of the organic silicon dispersion liquid on the surface of the carbon fibers by impregnating the carbon fibers with the organic silicon dispersion liquid containing the reinforcing particles, and can realize high-temperature co-melting synergy with the organic silicon polymer during heat treatment, so that the prepared composite carbon fiber material is not prone to cracking and surface coating is not prone to falling off, and the composite carbon fiber material has strong oxidation resistance and high tensile strength.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of carbon fiber composite materials, in particular to a method for preparing a composite carbon fiber material, the composite carbon fiber material and application. BACKGROUND

[0002] Carbon fiber has high modulus, high strength, low density, low thermal expansion, high temperature resistance, oxidation resistance, no creep, high thermal conductivity, corrosion resistance and other excellent properties, which can be used as a reinforcing body of composite materials, so that carbon fiber is widely used in composite materials with ceramic, resin, metal, carbon and other materials as matrix. However, carbon fiber is oxidized in air above 400℃, has poor oxidation resistance, leads to the performance of the material to be reduced, and the surface activity of carbon fiber without surface treatment is low, the wettability of some matrix is poor, and the combination ability is poor, which also leads to the performance of the composite material to be reduced. Moreover, at the temperature of preparing the composite material, carbon fiber is easy to react with some matrix, thereby damaging the fiber and seriously reducing the performance of the composite material.

[0003] Surface modification of carbon fiber is a common method to solve the above problems. On the one hand, slurry modification on the surface of carbon fiber is also a common method. Among them, SiC has high melting point, high temperature resistance, corrosion resistance, oxidation resistance and other properties, and is widely used in composite materials and fiber slurry. At present, the methods of SiC mainly include chemical vapor deposition (CVD) method, precursor impregnation and pyrolysis (PIP) method, physical vapor deposition (PVD) method, sol-gel (Sol-Gel) method and in-situ reaction method. Among them, the process of using PIP method to prepare SiC slurry on the surface of carbon fiber with polycarbosilane (PCS) as precursor is relatively mature, has the advantages of low process temperature, controllable composition and structure of product, low equipment requirement and the like. However, due to the shrinkage and thermal stress caused by the discharge of small molecular substances in the high temperature pyrolysis process of PCS, the coating is easy to crack and fall off, which affects its oxidation resistance, therefore, it is necessary to improve the phenomenon that the coating is easy to crack and fall off. SUMMARY

[0004] The purpose of the present application is to overcome the problems of easy cracking, low strength, poor adhesion and easy falling off of the coating in the prior art, and to provide a method for preparing a composite carbon fiber material, the composite carbon fiber material and application. The method uses an organic silicon dispersion liquid containing reinforcing particles to impregnate carbon fiber, which can improve the film forming performance of the organic silicon dispersion liquid on the surface of carbon fiber, and at the same time, the high temperature co-melting of the organic silicon polymer during heat treatment, synergistic effect, so that the prepared composite carbon fiber material is not easy to crack, the surface coating is not easy to fall off, and has strong oxidation resistance and high tensile strength.

[0005] To achieve the above object, the first aspect of the present application provides a method for preparing a composite carbon fiber material, characterized in that the method comprises: impregnating carbon fibers with an organic silicon dispersion liquid, and then curing and heat-treating the carbon fibers to obtain the composite carbon fiber material.

[0006] The organic silicon dispersion liquid contains an organic silicon polymer and reinforcing particles.

[0007] The reinforcing particles are selected from at least one of silicon dioxide, silicon carbide, boron carbide, graphite and boron nitride.

[0008] The second aspect of the present application provides a composite carbon fiber material, which is prepared by the method provided in the first aspect of the present application.

[0009] The third aspect of the present application provides an application of the method provided in the first aspect of the present application and the composite carbon fiber material provided in the second aspect of the present application in high-temperature structural parts.

[0010] Through the above technical solution, the method for preparing a composite carbon fiber material, the composite carbon fiber material and the application provided in the present application have the following beneficial effects:

[0011] 1. The impregnation of carbon fibers with the organic silicon dispersion liquid containing reinforcing particles can improve the film-forming performance of the organic silicon dispersion liquid on the surface of the carbon fibers, so that the surface of the composite carbon fiber material is uniform and smooth, and the organic silicon polymer and the reinforcing particles can co-melt at high temperature during heat treatment, thus achieving synergistic effect, so that the prepared composite carbon fiber material has high peeling strength, is not easy to crack, the coating is not easy to fall off, and has strong oxidation resistance and high tensile strength.

[0012] 2. The method is simple and easy to implement, and the composite carbon fiber material can be further combined with metal, ceramic, polymer and other materials, thereby reducing the damage of the sizing carbon fiber to the sizing material during the preparation of the composite material and the weaving process of the fibers. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is a scanning electron microscope image of the composite carbon fiber material prepared in Example 1;

[0014] Figure 2 is a scanning electron microscope image of the composite carbon fiber material prepared in Comparative Example 1. DETAILED DESCRIPTION

[0015] The endpoints of the ranges and any values disclosed herein are not limited to the precise values recited as the exact dimensions are not critical to the invention. Any numeric range recited is intended to include all values from the lower value to the upper value, inclusive of both values, and to sub-ranges falling within the specified range. In this context, individual points within a range should not be discounted as they can be used in combination with other points to define a new range. The endpoints of these ranges and any value between the endpoints are included as if specifically and individually listed herein.

[0016] The first aspect of the present application provides a method for preparing a composite carbon fiber material, characterized in that the method comprises: impregnating carbon fibers with an organosilicon dispersion liquid, and then curing and heat-treating the same to obtain a composite carbon fiber material.

[0017] The organosilicon dispersion liquid contains organosilicon polymers and reinforcing particles.

[0018] The reinforcing particles are selected from at least one of silicon dioxide, silicon carbide, boron carbide, graphite and boron nitride.

[0019] In the present application, the organosilicon dispersion liquid contains reinforcing particles, which can further improve the film-forming performance of the organosilicon dispersion liquid on the surface of the carbon fibers, so that the surface of the prepared composite carbon fiber material is smooth and uniform.

[0020] In the present application, the inventors have found that when the reinforcing particles are silicon carbide and boron nitride, the two together can further improve the oxidation resistance of the prepared composite carbon fiber material, and the surface coating is smoother and less prone to cracking, while the tensile strength of the composite material is improved.

[0021] Further, the reinforcing particles and the organosilicon polymers co-melt at high temperature during heat treatment, synergistically, so that the prepared composite carbon fiber material is less prone to cracking, the coating is less prone to falling off, and has strong oxidation resistance.

[0022] In the present application, the impregnation has no particular requirements and can be a conventional impregnation method in the art, such as atmospheric pressure impregnation, vacuum impregnation, ultrasonic impregnation, etc.

[0023] According to the present application, the carbon fibers are selected from at least one of carbon fiber bundles, carbon fiber cloths and three-dimensional carbon fiber preforms.

[0024] According to the present application, the organosilicon polymers are selected from polysilazane and / or polysiloxane.

[0025] In the present application, the organosilicon polymers are selected from polysilazane and / or polysiloxane, which can improve the bonding of the carbon fibers and the organosilicon polymers and further improve the interfacial strength of the composite carbon fiber material.

[0026] According to the present application, the number average molecular weight of the organosilicon polymers is 1000-5000.

[0027] In the present application, the number average molecular weight of the organic silicon polymer satisfies the above range, which can further improve the bonding force between the carbon fiber and the organic silicon polymer, improve the tensile strength of the composite carbon fiber material, and make the surface coating of the prepared composite carbon fiber material not easy to crack and fall off.

[0028] Further, the number average molecular weight of the organic silicon polymer is 1000-3000.

[0029] According to the present application, the particle size of the reinforcing particles is 10-100 microns.

[0030] In the present application, the particle size of the reinforcing particles satisfies the above range, which can make the organic silicon dispersion liquid impregnation more uniform, the surface of the prepared composite carbon fiber material more smooth, and further adjust the viscosity of the organic silicon dispersion liquid, so that the film-forming property is better.

[0031] Further, the particle size of the reinforcing particles is 20-40 microns.

[0032] According to the present application, the viscosity of the organic silicon dispersion liquid is 10-50 mPa·s.

[0033] In the present application, the viscosity of the organic silicon dispersion liquid satisfies the above range, which can improve the bonding force between the organic silicon dispersion liquid and the carbon fiber, further improve the interfacial strength of the composite carbon fiber material, make the prepared composite carbon fiber material not easy to crack, and have strong oxidation resistance, and at the same time have good film-forming property.

[0034] Further, the viscosity of the organic silicon dispersion liquid is 20-30 mPa·s.

[0035] In the present application, the organic silicon dispersion liquid contains 10-20 parts by weight of organic silicon polymer, 1-10 parts by weight of reinforcing particles, and 90-100 parts by weight of solvent.

[0036] Further, the solvent is an organic solvent.

[0037] Further, the organic solvent is selected from n-heptane and / or butyl acetate.

[0038] Further, the organic silicon dispersion liquid contains 10-15 parts by weight of organic silicon polymer, 1-6 parts by weight of reinforcing particles, and 60-100 parts by weight of solvent.

[0039] In the present application, the preparation method of the organic silicon dispersion liquid is not particularly limited, as long as the number average molecular weight of the organic silicon polymer, the particle size of the reinforcing particles, and the viscosity of the organic silicon dispersion liquid satisfy the above range.

[0040] In the present application, the organic silicon dispersion liquid can be prepared by the following method: 10-20 parts by weight of organic silicon polymer is added into 60-100 parts by weight of solvent and stirred uniformly, 1-10 parts by weight of reinforcing particles with particle size of 50-100 g is added, and the organic silicon dispersion liquid is obtained by stirring.

[0041] According to the present application, the amount of the organic silicon dispersion liquid is 1-30 wt% of the mass of the carbon fiber.

[0042] In the present application, the amount of the organic silicon dispersion liquid meets the above range, so that the composite carbon fiber material has strong oxidation resistance and is not easy to crack.

[0043] Further, the amount of the organic silicon dispersion liquid is 5-30 wt% of the mass of the carbon fiber.

[0044] According to the present application, the carbon fiber is subjected to impurity removal treatment before being impregnated.

[0045] In the present application, the impurity removal treatment conditions include: impurity removal for 1-2 h at 50-60℃ and 0.1-0.15 MPa in the presence of an impurity removal agent.

[0046] According to the present application, the impurity removal agent is selected from at least one of acetone, ethanol and chloroform.

[0047] According to the present application, the method further comprises radiation treatment after the impurity removal treatment of the carbon fiber.

[0048] In the present application, the carbon fiber is subjected to radiation treatment, which can improve the interfacial compatibility of the carbon fiber, and combined with the organic silicon polymer, improve the combination of the carbon fiber and the organic silicon dispersion polymer, and further improve the interfacial strength of the composite carbon fiber material and improve the oxidation resistance performance in cooperation with the reinforcing particles.

[0049] According to the present application, the radiation medium during the radiation treatment is selected from at least one of alpha rays, beta rays, gamma rays, X-rays, high-energy electron beams and ultraviolet rays.

[0050] In the present application, the radiation medium during the radiation treatment is preferably a high-energy electron beam.

[0051] In the present application, the high-energy electron beam is a high-energy electron beam of a high-energy electron accelerator.

[0052] According to the present application, the radiation treatment conditions include: radiation dose of 200-800 KGy and radiation time of 1-5 min.

[0053] In the present application, the conditions of the radiation treatment meet the above range, which can further improve the interface compatibility of the composite carbon fiber material, and further improve the binding force between the carbon fiber and the silicone dispersion liquid, and improve the peeling strength of the composite carbon fiber material.

[0054] According to the present application, the conditions of the radiation treatment include: the irradiation dose is 200-400 KGy, and the irradiation time is 1-2 min.

[0055] According to the present application, the conditions of the curing include: curing at 300-500℃ for 1-3h.

[0056] Further, the conditions of the curing include: curing at 300-400℃ for 1-2h.

[0057] According to the present application, the conditions of the heat treatment include: treating at 800-1500℃ for 1-3h in the presence of a protective gas.

[0058] In the present application, the type of the protective gas is not particularly limited, which can be nitrogen and / or inert gas.

[0059] Further, the conditions of the heat treatment include: treating at 1000-1500℃ for 1-2h in the presence of a protective gas.

[0060] In a preferred embodiment of the present application, the method for preparing the composite carbon fiber material comprises:

[0061] S1, the carbon fiber is treated with a decontaminating agent at 50-60℃ and 0.1-0.15 MPa for 1-2h, and then subjected to radiation treatment, the conditions of the radiation treatment include: the radiation dose is 200-800 KGy, and the radiation time is 1-5 min, to obtain a carbon fiber precursor;

[0062] S2, 10-20 parts by weight of the silicone polymer is weighed and added to 90-100 parts by weight of the solvent to stir uniformly, and 1-10 parts by weight of the reinforcing particles with a particle size of 10-100 microns is added to stir to obtain a silicone dispersion liquid;

[0063] S3, the carbon fiber precursor is impregnated with the above-mentioned silicone dispersion liquid, and then cured at 300-500℃ for 1-3h to obtain a composite carbon fiber material precursor;

[0064] S4, the above-mentioned composite carbon fiber material precursor is treated at 800-1500℃ for 1-3h in the presence of a protective gas to obtain a composite carbon fiber material.

[0065] The second aspect of the present application provides a composite carbon fiber material, which is prepared by the method provided in the first aspect of the present application.

[0066] According to the present application, the composite carbon fiber material comprises carbon fibers and a ceramic material coating attached to the surface of the carbon fibers.

[0067] In the present application, the ceramic material coating attached to the surface of the carbon fibers is not easy to fall off and crack.

[0068] According to the present application, the weight loss rate of the composite carbon fiber material at 1000℃ is not more than 20wt%.

[0069] Further, the weight loss rate of the composite carbon fiber material at 1000℃ is not more than 10wt%.

[0070] According to the present application, the mass of the ceramic material coating is 1-10wt% based on the total weight of the composite carbon fiber material.

[0071] In the present application, when the mass of the ceramic material coating meets the above range, the ceramic material coating on the surface of the prepared composite carbon fiber material can be fully combined with the carbon fibers, and the ceramic material coating is not easy to crack and fall off.

[0072] Further, the mass of the ceramic material coating is 1-2wt% based on the total weight of the composite carbon fiber material.

[0073] According to the present application, the ceramic material coating contains SiO2 and at least one ceramic material selected from Si3N4, SiC, B4C, graphite and BN.

[0074] The third aspect of the present application provides an application of the method provided in the first aspect and the composite carbon fiber material provided in the second aspect in the field of high-temperature structural materials.

[0075] The present application will be described in detail below through examples. In the following examples,

[0076] The weight loss rate of the composite carbon fiber material is measured by the thermal gravimetric method (nitrogen atmosphere, 25-1500℃);

[0077] The mass of the ceramic material coating is measured by the difference method, specifically: Mceramic material coating = Mcomposite carbon fiber material - Mcarbon fiber; wherein M represents mass;

[0078] The crack condition and smoothness of the surface of the composite carbon fiber material are measured by scanning electron microscopy;

[0079] The film forming performance is characterized by leveling property, which is observed by naked eye and evaluated by grading method (0-5 grade), with 0 grade indicating excellent and 5 grade indicating unqualified;

[0080] The tensile strength of the composite carbon fiber material was obtained by ISO 11566-1996 method test.

[0081] Example 1

[0082] S1, the carbon fiber cloth was treated with acetone at 60°C and 0.1 MPa for 1 h, then placed under a high-energy electron beam with an irradiation dose of 300 KGy for 2 min to obtain a carbon fiber precursor;

[0083] S2, 12 g of polysilazane (number average molecular weight 1500) was weighed and added to 90 g of butyl acetate and stirred to obtain a silicone dispersion liquid with a viscosity of 20 mPa·s, and 5 g of silica particles with a particle size of 20 microns was added;

[0084] S3, the above silicone dispersion liquid (10 g) was used for ultrasonic immersion of the carbon fiber precursor (50 g), wherein the amount of silicone dispersion liquid was 20 wt% of the mass of the carbon fiber, and the composite carbon fiber material precursor was obtained by curing at 300°C for 1 h;

[0085] S4, the above composite carbon fiber material precursor was treated at 1200°C for 2 h under a nitrogen atmosphere to obtain a composite carbon fiber material A1;

[0086] Wherein, the mass of the ceramic material coating is 0.5 g based on the total weight of the composite carbon fiber material A1, accounting for 1 wt% of the mass of the composite carbon fiber material, and the ceramic material coating contains SiO2, Si3N4 and SiC.

[0087] Example 2

[0088] S1, the carbon fiber cloth was treated with ethanol at 60°C and 0.1 MPa for 1 h, then placed under a high-energy electron beam with an irradiation dose of 400 KGy for 2 min to obtain a carbon fiber precursor;

[0089] S2, 10 g of polysilazane (number average molecular weight 3000) was weighed and added to 90 g of n-heptane and stirred to obtain a silicone dispersion liquid with a viscosity of 20 mPa·s, and 2 g of silica particles with a particle size of 20 microns was added;

[0090] S3, the above silicone dispersion liquid (15 g) was used for ultrasonic immersion of the carbon fiber precursor (50 g), wherein the amount of silicone dispersion liquid was 30 wt% of the mass of the carbon fiber, and the composite carbon fiber material precursor was obtained by curing at 300°C for 1.5 h;

[0091] S4, the above composite carbon fiber material precursor was treated at 1000°C for 1 h under a nitrogen atmosphere to obtain a composite carbon fiber material A2;

[0092] The mass of the ceramic material coating is 1 g, accounting for 2 wt% of the mass of the composite carbon fiber material, based on the total weight of the composite carbon fiber material A2; the ceramic material coating contains SiO2, Si3N4 and SiC.

[0093] Example 3

[0094] S1, after the carbon fiber cloth is impurity-removed at 60°C and 0.1 MPa for 1 h using chloroform, the carbon fiber cloth is placed under a high-energy electron beam with an irradiation dose of 600 KGy for radiation treatment for 2 min to obtain a carbon fiber precursor;

[0095] S2, 10 g of polysilazane (number average molecular weight 3000) is weighed and added to 90 g of n-heptane to be stirred uniformly, and 2 g of silica particles with a particle size of 30 microns is added to obtain an organic silicon dispersion liquid with a viscosity of 20 mPa·s;

[0096] S3, the above organic silicon dispersion liquid (12 g) is used for ultrasonic impregnation of the carbon fiber precursor (50 g), wherein the amount of the organic silicon dispersion liquid is 24 wt% of the mass of the carbon fiber, and the carbon fiber precursor is cured at 300°C for 1 h to obtain a composite carbon fiber material precursor;

[0097] S4, the above composite carbon fiber material precursor is treated at 800°C for 2 h under a nitrogen atmosphere to obtain a composite carbon fiber material A3;

[0098] The mass of the ceramic material coating is 0.75 g, accounting for 1.5 wt% of the mass of the composite carbon fiber material, based on the total weight of the composite carbon fiber material A3; the ceramic material coating contains SiO2, Si3N4 and SiC.

[0099] Example 4

[0100] S1, after the carbon fiber cloth is impurity-removed at 60°C and 0.1 MPa for 1 h using acetone, the carbon fiber cloth is placed under a high-energy electron beam with an irradiation dose of 800 KGy for radiation treatment for 1 min to obtain a carbon fiber precursor;

[0101] S2, 10 g of polysilazane (number average molecular weight 3000) is weighed and added to 90 g of n-heptane to be stirred uniformly, and 2 g of silica particles with a particle size of 40 microns is added to obtain an organic silicon dispersion liquid with a viscosity of 25 mPa·s;

[0102] S3, the above organic silicon dispersion liquid (15 g) is used for ultrasonic impregnation of the carbon fiber precursor (50 g), wherein the amount of the organic silicon dispersion liquid is 30 wt% of the mass of the carbon fiber, and the carbon fiber precursor is cured at 300°C for 1 h to obtain a composite carbon fiber material precursor;

[0103] S4, the above composite carbon fiber material precursor is treated at 1200 DEG C for 2h under nitrogen atmosphere to obtain a composite carbon fiber material A4;

[0104] The mass of the ceramic material coating is 1g, accounting for 2wt% of the mass of the composite carbon fiber material A4; and the ceramic material coating contains SiO2, Si3N4 and SiC.

[0105] Example 5

[0106] S1, the carbon fiber bundle is subjected to impurity removal using acetone at 60 DEG C and 0.1 MPa for 1h, and then is subjected to radiation treatment for 2min under a high-energy electron beam with a radiation dose of 400 KGy to obtain a carbon fiber precursor;

[0107] S2, 10g of polysilazane with a number average molecular weight of 3000 is weighed, added into 90g of n-heptane, and stirred to obtain an organic silicon dispersion liquid, and 2g of silica particles with a particle size of 20 microns is added to obtain an organic silicon dispersion liquid with a viscosity of 20mPa·s;

[0108] S3, the above organic silicon dispersion liquid (10g) is used for ultrasonic impregnation of the carbon fiber precursor (50g), wherein the amount of the organic silicon dispersion liquid is 20wt% of the mass of the carbon fiber, and the composite carbon fiber material precursor is obtained by curing at 300 DEG C for 1h;

[0109] S4, the above composite carbon fiber material precursor is treated at 1000 DEG C for 2h under nitrogen atmosphere to obtain a composite carbon fiber material A5;

[0110] The mass of the ceramic material coating is 0.65g, accounting for 1.3wt% of the mass of the composite carbon fiber material A5; and the ceramic material coating contains SiO2, Si3N4 and SiC.

[0111] Example 6

[0112] The method is consistent with that of Example 1, except that 5g of silica is replaced by 3g of silicon carbide and 2g of boron nitride with the same particle size, and the viscosity of the organic silicon dispersion liquid is 30mPa·s to obtain a composite carbon fiber material A6;

[0113] The mass of the ceramic material coating is 0.6g, accounting for 1.2wt% of the mass of the composite carbon fiber material A6; and the ceramic material coating contains SiO2, Si3N4, SiC and BN.

[0114] Example 7

[0115] The method is consistent with that of Example 1, except that no radiation treatment is performed to obtain a composite carbon fiber material A7;

[0116] The mass of the ceramic material coating is 1.5 g, accounting for 3 wt% of the mass of the composite carbon fiber material A7; the ceramic material coating contains SiO2, Si3N4 and SiC.

[0117] Example 8

[0118] The method is consistent with that of Example 1, except that the added amount of the silica particles is 50 g, and the viscosity of the prepared silicone dispersion liquid is 50 mPa·s. Finally, the composite carbon fiber material A8 is prepared.

[0119] The mass of the ceramic material coating is 2 g, accounting for 4 wt% of the mass of the composite carbon fiber material A8; the ceramic material coating contains SiO2, Si3N4 and SiC.

[0120] Example 9

[0121] The method is consistent with that of Example 1, except that the particle size of the silica particles is 50 microns, and the viscosity of the prepared silicone dispersion liquid is 50 mPa·s. Finally, the composite carbon fiber material A9 is prepared.

[0122] The mass of the ceramic material coating is 2 g, accounting for 4 wt% of the mass of the composite carbon fiber material A9; the ceramic material coating contains SiO2, Si3N4 and SiC.

[0123] Example 10

[0124] The method is consistent with that of Example 1, except that the above-mentioned silicone dispersion liquid (2 g) is used for ultrasonic immersion of the carbon fiber precursor (50 g), and the amount of the silicone dispersion liquid is 50 wt% of the mass of the carbon fiber. Finally, the composite carbon fiber material A10 is prepared.

[0125] The mass of the ceramic material coating is 0.25 g, accounting for 0.5 wt% of the mass of the composite carbon fiber material A10; the ceramic material coating contains SiO2, Si3N4 and SiC.

[0126] Example 11

[0127] The method is consistent with that of Example 1, except that the particle size of the silica particles is 150 microns, and the viscosity of the prepared silicone dispersion liquid is 100 mPa·s. Finally, the composite carbon fiber material A11 is prepared.

[0128] The mass of the ceramic material coating is 0.5 g, accounting for 1 wt% of the mass of the composite carbon fiber material A11, and the ceramic material coating contains SiO2, Si3N4 and SiC.

[0129] Example 12

[0130] The method is consistent with that of Example 1, except that the molecular weight of the polysilazane is 5000, and the composite carbon fiber material A12 is finally prepared.

[0131] The mass of the ceramic material coating is 0.5 g, accounting for 1 wt% of the mass of the composite carbon fiber material A12, and the ceramic material coating contains SiO2, Si3N4 and SiC.

[0132] Example 13

[0133] The method is consistent with that of Example 1, except that the irradiation dose is 150 KGy, and the composite carbon fiber material A12 is finally prepared.

[0134] The mass of the ceramic material coating is 0.85 g, accounting for 1.7 wt% of the mass of the composite carbon fiber material A12, and the ceramic material coating contains SiO2, Si3N4 and SiC.

[0135] Example 14

[0136] The method is consistent with that of Example 1, except that no impurity removal treatment is performed, and the composite carbon fiber material A14 is obtained.

[0137] The mass of the ceramic material coating is 1.05 wt%, accounting for 2.1 wt% of the mass of the composite carbon fiber material A14, and the ceramic material coating contains SiO2, Si3N4 and SiC.

[0138] Comparative Example 1

[0139] The method is consistent with that of Example 1, except that the organic silicon dispersion liquid does not contain silica particles, but only contains 12 g of polysilazane and 90 g of butyl acetate, 150 mPa·s, and the composite carbon fiber material D1 is finally prepared.

[0140] The mass of the ceramic material coating is 5 wt%, accounting for 5 wt% of the mass of the composite carbon fiber material D1, and the ceramic material coating contains SiO2, Si3N4 and SiC.

[0141] Comparative Example 2

[0142] The method of Example 1 is consistent, except that the silica particles are replaced with the same mass of titanium dioxide particles, and finally a composite carbon fiber material D2 is prepared;

[0143] The mass of the ceramic material coating is 0.5 g, and the mass of the ceramic material coating is 1 wt% based on the total weight of the composite carbon fiber material D2, wherein the ceramic material coating contains SiO2, TiO2, Si3N4 and SiC.

[0144] Test Example

[0145] The composite carbon fiber materials prepared by the examples and comparative examples are tested for thermal weight loss, peel strength and leveling property, and the results are shown in Table 1.

[0146] Table 1

[0147]

[0148] Note: Ceramic material content a refers to the mass of the ceramic material coating based on the total weight of the composite carbon fiber material

[0149] As can be seen from the results in Table 1, the composite carbon fiber materials prepared by Examples 1-14 using the method provided by the present application have a suitable ceramic content, and the weight loss rate is not greater than 20 wt%, have good oxidation resistance, and have good leveling property, all at level 4 or above, and have high composite tensile strength.

[0150] Further, Examples 1-6 meeting the preferred scheme of the present application have significantly better technical effects, with a weight loss rate of less than 10 wt%, stronger oxidation resistance, and leveling property of level 3 or above, and a composite tensile strength of not less than 3.3 GPa.

[0151] Among them, Example 6 uses silicon carbide and boron nitride together, which can achieve better technical effects, lower weight loss rate, stronger oxidation resistance, and leveling property of level 0, and a composite tensile strength of 3.9 GPa.

[0152] As can be seen from Comparative Example 1, too high a ceramic content can result in a higher composite tensile strength, but can cause the surface coating of the composite carbon fiber to crack and have poor oxidation resistance, and cannot be applied.

[0153] As can be seen from Figure 1 Example 1, the composite carbon fiber material prepared has a smooth surface without cracks or signs of falling off; while Figure 2 In Comparative Example 1, the composite carbon fiber material prepared does not contain reinforcing particles, and the surface coating has obvious cracks.

[0154] Figure 1and Figure 2 The organic silicon polymer and the reinforcing particles can synergize to make the carbon fibers in the composite carbon fiber material and the ceramic material coating attached to the surface of the carbon fibers tightly combined, and the ceramic material coating is not prone to cracking.

[0155] The above describes the preferred embodiments of the present application, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including that each technical feature is combined in any other suitable manner, and these simple modifications and combinations should also be considered as disclosed by the present application, and all fall within the protection scope of the present application.

Claims

1. A method of producing a composite carbon fiber material, characterized by, The method comprises: impregnating carbon fibers with an organic silicon dispersion liquid, and then curing and heat treating the carbon fibers to obtain a composite carbon fiber material. The organic silicon dispersion liquid contains 10-20 parts by weight of an organic silicon polymer, 1-10 parts by weight of reinforcing particles, and 90-100 parts by weight of a solvent. The organic silicon polymer is selected from polysilazane and / or polysiloxane. The reinforcing particles are silicon carbide and boron nitride, and the particle size of the reinforcing particles is 10-100 microns.

2. The method of claim 1, wherein, The carbon fibers are selected from at least one of carbon fiber bundles, carbon fiber cloths, and three-dimensional carbon fiber preforms. The number average molecular weight of the organic silicon polymer is 1000-5000.

3. The method of claim 1, wherein, The viscosity of the organic silicon dispersion liquid is 10-50 mPa·s. The amount of the organic silicon dispersion liquid is 1-30 wt% of the mass of the carbon fibers.

4. The method of claim 3, wherein, The amount of the organic silicon dispersion liquid is 5-30 wt% of the mass of the carbon fibers.

5. The method of claim 1, wherein, The method further comprises impurity removal treatment of the carbon fibers before impregnation. The impurity removal treatment is performed at 50-60℃ and 0.1-0.15 MPa for 1-2 h in the presence of an impurity removal agent. The impurity removal agent is selected from at least one of acetone, ethanol, and chloroform. The method further comprises radiation treatment after the impurity removal treatment of the carbon fibers, and the radiation medium in the radiation treatment is selected from at least one of α-rays, β-rays, γ-rays, X-rays, high-energy electron beams, and ultraviolet rays.

6. The method of claim 1, wherein, The radiation treatment is performed at a radiation dose of 200-400 KGy for 1-2 min. The curing is performed at 300-500℃ for 1-3 h.

7. A composite carbon fiber material characterized by, The heat treatment is performed at 800-1500℃ for 1-3 h in the presence of a protective gas.

8. The composite carbon fiber material of claim 7, wherein, The composite carbon fiber material is prepared by the method of any one of claims 1-6. The composite carbon fiber material comprises carbon fibers and a ceramic material coating attached to the surface of the carbon fibers.

9. The composite carbon fiber material of claim 8, wherein, The mass of the ceramic material coating is 1-10 wt% based on the total weight of the composite carbon fiber material. The weight loss rate of the composite carbon fiber material at 1000℃ is not more than 20 wt%. The ceramic material coating contains SiO2 and at least one ceramic material selected from Si3N4, SiC, and BN.

10. Use of the composite carbon fiber material of any one of claims 7-9 in high-temperature structural parts.

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