Tungsten-modified c / c composite material and preparation method thereof

Abstract

The present application belongs to the technical field of preparation of carbon fiber reinforced carbon-based composite material, and discloses a tungsten modified C / C composite material and a preparation method thereof. The C / C composite material is placed on a filter membrane, a suspension of tungsten powder is suction filtered to obtain a first composite structure of tungsten powder and the C / C composite material, and the first composite structure is dried. The dried first composite structure is subjected to carbon deposition densification to obtain the tungsten modified C / C composite material. At the interface between the coating and the substrate, the tungsten is distributed in a sawtooth shape, which significantly enhances the bonding force between the coating and the substrate. In the initial stage of ablation, the tungsten coating transfers heat on the surface of the composite material to the substrate, and the tungsten in the substrate further transfers the heat to the inside of the material, thereby reducing the thermal stress concentrated on the surface of the material. With the gradual increase of temperature, the tungsten in the substrate first chemically reacts with C to strongly absorb heat and the surface oxidation forms WO3 to evaporate and absorb heat, thereby reducing the heating rate and the ablation temperature on the surface of the composite material, and the ablation resistance of the material can be effectively improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of carbon fiber reinforced carbon-based composite material preparation, and particularly relates to a tungsten modified C / C composite material and a preparation method thereof. BACKGROUND

[0002] Carbon / carbon (C / C) composite material has the advantages of low density, low thermal expansion coefficient, high specific strength, excellent high-temperature mechanical properties, etc., and is an ideal high-temperature structural material in inert environment. However, C / C composite material will be oxidized in an oxygen environment at 370℃, and the oxidation rate will rapidly increase when the temperature exceeds 500℃, which seriously degrades the high-temperature performance of the C / C composite material. At present, coating technology and matrix modification are effective ways to improve the oxidation resistance / ablation resistance of C / C composite material. W has a high melting point of 3422℃, high modulus and low thermal expansion coefficient, and has been used as a key throat liner material for solid rocket engines. However, the density of W throat liner is as high as 19.35 g / cm 3 , which is difficult to meet the light weight requirement of high-speed aircraft. At present, throat liner materials basically use C / C composite material with lower density. However, in terms of ablation resistance, C / C composite material throat liner is still inferior to W throat liner. Literature 1“[1] Xie H Z, Li R Z, Cui H, et al. Plasma sprayed tungsten-based materials and thin-walled components [J]. Solid Rocket Technology, 2012, 35(06):812-815+820.” prepared W-based thin-walled components by atmospheric plasma spraying, and the throat material surface had no ablation marks after 6.4 s of hot test at a temperature of about 3000℃ and an average pressure of 3.2 MPa. This provides a new idea for improving the ablation resistance of C / C composite material. The W is used to modify the C / C composite material to fully utilize the advantages of both materials and obtain a light-weight and ablation-resistant composite material.

[0003] Literature 2“Zhou, Z., Wang, Y., Gong, J. et al. Ablation Resistance of C / CComposites with Atmospheric Plasma-Sprayed W Coating. J Therm Spray Tech25,1657-1665 (2016). The linear ablation rate of the W-coated C / C composites was reduced by 23.55% after 150 s of ablation in oxyacetylene flame compared with the Zr / Cu infiltrated C / C composites. APS can quickly prepare W coating, but in the process of spraying, the coating surface is easy to be oxidized to form loose porous tungsten oxide, at the same time, the coating is also easy to produce larger residual stress, which will reduce the bonding strength between the W coating and the substrate, and make the coating surface warp and crack.

[0004] Therefore, if the C / C composite is modified by W, while avoiding the disadvantage that the W coating on the surface of the C / C composite is easy to fall off and oxidize, it is urgent to find a new method to introduce metal W into the C / C composite to improve its ablation resistance. SUMMARY

[0005] In view of the deficiencies in the prior art, the purpose of the present application is to provide a tungsten modified C / C composite and a preparation method thereof, in order to prepare a light and ablation resistant composite material.

[0006] To achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0007] A preparation method of a tungsten modified C / C composite, comprising the following processes:

[0008] The C / C composite is placed on a filter membrane, the suspension of tungsten powder is filtered, a first composite structure of tungsten powder and C / C composite is obtained, and the first composite structure is dried.

[0009] The dried first composite structure is subjected to carbon deposition densification to obtain a tungsten modified C / C composite.

[0010] Preferably, during each filtration process, the filtration is continued until the surface of the C / C composite cannot be further filtered into the suspension, and then the drying is performed.

[0011] Preferably, the preparation method of the tungsten modified C / C composite further comprises the following processes:

[0012] The processes of placing the dried first composite structure on a filter membrane, filtering the suspension of tungsten powder, and drying the first composite structure are repeated until the first composite structure no longer increases in weight.

[0013] Preferably, before drying the first composite structure of tungsten powder and C / C composite, the first composite structure is first rinsed with anhydrous ethanol to remove the residual powder on the surface of the first composite structure, and then dried.

[0014] Preferably, the C / C composite material and the non-woven fabric layer are alternately arranged and face upward during the filtration.

[0015] Preferably, the solvent is anhydrous ethanol, and the mass ratio of the tungsten powder to the anhydrous ethanol is 1:3-4.

[0016] Preferably, the particle size of the tungsten powder is 3-5 μm, and the density of the C / C composite material is 1.0-1.3 g / cm 3 .

[0017] Preferably, the preparation method of the tungsten modified C / C composite material further comprises the following processes: the C / C composite material is first cleaned and pretreated, and the C / C composite material after the cleaning and pretreatment is subjected to the filtration.

[0018] During the cleaning and pretreatment of the C / C composite material, the C / C composite material is subjected to ultrasonic cleaning, and then dried at 60-80℃ for 10-12 h.

[0019] Preferably, the process of densifying the dried first composite structure by carbon deposition comprises:

[0020] In a protective atmosphere, pyrolytic carbon is deposited on the surface of the dried first composite structure by using methane gas, so as to realize the densification of the first composite structure by carbon deposition.

[0021] Preferably, the temperature during the deposition of the pyrolytic carbon is 1030-1070℃, and the time is 20-30 h.

[0022] The application further provides a tungsten modified C / C composite material prepared by the preparation method as described above.

[0023] Compared with the prior art, the application has the following beneficial effects:

[0024] The present application takes tungsten powder and anhydrous ethanol as raw materials, introduces tungsten into the surface layer of C / C composite material through vacuum filtration process, and then fixes the W powder in the C / C composite material through chemical vapor infiltration process, and densifies the composite material. The tungsten modified C / C composite material prepared by the preparation method of the present application has sawtooth-shaped W distributed at the interface between the coating and the substrate, which significantly enhances the bonding force between the coating and the substrate. Metal W has excellent thermal conductivity. In the initial ablation stage, the coating W transfers the heat on the surface of the composite material to the substrate, and the substrate W further transfers the heat to the inside of the material, reducing the thermal stress concentrated on the surface of the material. With the gradual increase of temperature, the substrate W first chemically reacts with C to strongly absorb heat and the surface oxidation forms WO3 to evaporate and absorb heat, which reduces the heating rate and ablation temperature of the surface of the composite material, and can effectively improve the ablation resistance of the material. In addition, the preparation process of the present application is simple, short in cycle, low in cost, and can prepare components with complex shape, which has great development potential. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a flow chart of the preparation method of the tungsten modified C / C composite material of the present application.

[0026] Figure 2 (a) is a surface morphology image (low magnification image) of the low-density carbon-carbon composite material after filtration of W according to Example 1 of the present application; Figure 2 (b) is a surface morphology image (high magnification image) of the low-density carbon-carbon composite material after filtration of W according to Example 1 of the present application.

[0027] Figure 3 (a) is a cross-sectional backscattering image (high magnification image) of the C / C-W composite material according to Example 1 of the present application; Figure 3 (b) is a cross-sectional backscattering image (low magnification image) of the C / C-W composite material according to Example 1 of the present application.

[0028] Figure 4 is the temperature change curve of the surface of the sample when the C / C-W composite material according to Example 1 of the present application is subjected to ablation test for 60 s.

[0029] Figure 5 is a cross-sectional SEM image of the composite material obtained in Comparative Example 1 of the present application.

[0030] Figure 6 is an XRD pattern of the composite material obtained in Comparative Example 3 of the present application. DETAILED DESCRIPTION

[0031] The principles and features of the present application are described below in conjunction with the accompanying drawings, in which the examples are used to explain the present application and are not intended to limit the scope of the present application. The specific conditions not specified in the examples are carried out according to the conventional conditions or the conditions recommended by the manufacturer. In this paper, all the characteristics defined in the form of numerical range or percentage range, such as numerical value, quantity, content and concentration, are only for the sake of brevity and convenience. Therefore, the description of the numerical range or percentage range should be considered to have covered and specifically disclosed all possible sub-ranges and individual numerical values within the range (including integers and fractions).

[0032] Referring to Figure 1 , the preparation method of tungsten modified C / C composite material includes the following steps:

[0033] S1: Mix anhydrous ethanol and 3-5 μm W powder into a slurry, the mass ratio of W powder to anhydrous ethanol is 1: (3-4), put into a stirrer, stir under a magnetic stirrer for 1-2 h, and form a suspension.

[0034] S2: Process the C / C composite material with a density of 1.0-1.3 g / cm 3 to a sample of φ 28 mm x 8 mm, polish the surface with a grinding disc, then ultrasonic clean and dry in an oven at 70-80℃ for 10-12 h;

[0035] S3: Take a piece of 50 mm, 0.1 μm pore size organic filter membrane, wet with alcohol, and place it flat on the sand core filter so that the filter membrane is tightly attached to the filter. Place the sample (i.e. C / C composite material) on the filter membrane (xy plane (i.e. the surface of the tire layer and the weft layer alternately distributed) upward), cover with a cylindrical glass funnel, and fix the device with an aluminum alloy clamp. After the device is fixed, turn on the vacuum pump and check if the vacuum pump can be used normally by dripping anhydrous ethanol. Use a dropper to evenly drop the slurry on the surface of the sample, and the internal and external pressure difference formed by the vacuum pump will press the anhydrous ethanol inside the sample out, and the W powder will remain inside the sample. Repeat this operation until the sample surface cannot be pumped into W powder. During this period, continuously stir the slurry to prevent powder deposition. Take out the sample, rinse off the surface residual powder with anhydrous ethanol, and dry in an oven at 70-80℃ for 10-12 h before weighing.

[0036] S4: Repeat step S3 until the weight gain of the dried sample is no longer obvious.

[0037] S5: The composite material obtained in S4 is fixed in a mold of a small chemical vapor deposition furnace. The mold is placed in the furnace, and vacuum is drawn to below -0.01 MPa. Ar gas is introduced as a protective gas, and the flow rate is set to 1 L / min. The temperature is raised to 1030-1070℃ at a rate of 5-8℃ / min. Then, methane is introduced, and the flow rate of methane is set to 0.6 L / min, and the flow rate of argon is set to 2.4 L / min, and the flow rate ratio of methane to argon is 1:4. After heat preservation for 20-30 h, the temperature is lowered to 300℃, and the furnace is cooled, and a dense C / C-W composite material is obtained. Through a chemical vapor infiltration process, the W coating on the surface of the composite material is densified, and the C / C-W composite material is densified, and thus a W-coated and modified C / C integrated composite material is obtained.

[0038] Through the above scheme of the present application, the W is distributed in a jagged manner at the interface of the obtained C / C-W composite material, which significantly enhances the bonding force between the coating and the substrate. In the ablation process, the metal W can maintain the surface temperature of the C / C composite material stable for nearly 10 s at 1170-1200℃ due to its good thermal conductivity and the large amount of heat absorption during carbonization. At the same time, the WO3 generated by oxidation during ablation evaporates and absorbs heat above 1800℃, thereby slowing down the rising speed of the surface temperature of the sample, which significantly improves the ablation resistance of the C / C composite material. The composite material prepared by the present application also has the advantages of simple process, low cost, and short cycle.

[0039] Example 1:

[0040] The preparation method of the tungsten-modified C / C composite material of the present embodiment includes the following steps:

[0041] S1: W powder and anhydrous ethanol are weighed in a weight ratio of 1:3 in a beaker, and stirred at room temperature with a magnetic stirrer for 2 h to form a suspension;

[0042] S2: The C / C composite material with a density of 1.3 g / cm 3 is cleaned by ultrasonic cleaning and placed in a 70℃ oven for drying for 12 h;

[0043] S3: A vacuum filtration device is set up, and the sample dried in S2 (xy plane upward) is placed on the filter membrane. The slurry is dropped onto the surface of the sample with a dropper, and the powder is uniformly distributed on the surface. Until no W powder can be drawn into the surface. The sample is removed, and the surface residual powder is washed off with anhydrous ethanol. After drying in a 70℃ oven for 12 h, the sample is weighed.

[0044] S4: Repeat S3 until the sample weight gain is no longer obvious. Figure 2(a) is a high magnification image of the surface of the C / C composite material after the W powder is filtered in this embodiment, and it can be seen that the 3-5 μm W powder is tightly distributed around the carbon fibers. Figure 2(b) is a low magnification image of the surface of the C / C composite material after the W powder is filtered in this embodiment, and it can be seen that the W powder is mainly distributed in the mesh tire layer, and less in the weft cloth layer.

[0045] S5: The composite material obtained in S4 is fixed in a mold of a small chemical vapor deposition furnace. The mold is placed in the furnace, and vacuum is drawn to below -0.01 MPa. Ar gas is introduced as a protective gas, and the flow rate is set to 1 L / min. The temperature is raised to 1070°C at a rate of 5-8°C / min. Then, methane is introduced, and the flow rate is set to 0.6 L / min, and the argon flow rate is set to 2.4 L / min, and the methane to argon flow rate ratio is 1:4. After 20 h of heat preservation, the furnace is cooled, and a dense C / C-W composite material is obtained, with a porosity of 20.19%. Figure 3(a) is a low magnification cross-sectional backscattering image of the C / C-W composite material in this embodiment, and it can be seen that the surface of the composite material has a W coating with a thickness of 100 μm. The W is distributed up to 400 μm in the mesh tire layer, and the overall structure is a sawtooth structure, and the W coating tightly grips the C / C-W substrate, and the bonding force between the coating and the substrate is effectively enhanced, achieving the effect of W on the C / C composite material substrate-coating integration modification. Figure 3(b) is a high magnification cross-sectional backscattering image of the C / C-W composite material in this embodiment, and the white phase is W. In the densification process of the composite material, W does not carbonize or oxidize. The pyrolytic carbon deposited during the chemical vapor infiltration process tightly fixes the W powder around the carbon fibers. Figure 4 Figure 4 is a curve of the change in the surface temperature of the C / C-W composite material in this embodiment during the low-power ablation process, and it can be seen that there is a clear plateau region at 1180°C. In this temperature range, the W and C react vigorously and absorb heat, causing the surface temperature of the sample to remain stable for a period of time. After 1800°C, the rate of increase of the surface temperature of the sample slows down, which is the effect of the evaporation of WO3 formed by the oxidation of the surface of the sample. This buffers the thermal stress experienced by the sample during ablation, improving its ablation resistance.

[0046] Example 2:

[0047] The method for preparing the tungsten-modified C / C composite material in this embodiment includes the following steps:

[0048] S1: W powder and anhydrous ethanol are weighed in a ratio of 1:3 by weight and placed in a beaker, and stirred at room temperature with a magnetic stirrer for 1 h to form a suspension;

[0049] S2: The density of the suspension is 1.0 g / cm 3C / C composite material ultrasonic cleaning clean, put into 70℃ oven drying 10 h;

[0050] S3: build a vacuum filtration device, the sample (xy surface up) after drying S2 placed on the filter membrane. With a pipette extract slurry into the sample surface, control the uniform distribution of powder on the surface. Until the surface can not be extracted into the W powder. Remove the sample, with anhydrous ethanol flush away the surface powder, in 80℃ oven drying 10 h after weighing.

[0051] S4: repeat S3 step until the sample weight gain is no longer obvious.

[0052] S5: the composite material obtained by S4 is fixed in the mold of a small chemical vapor deposition furnace. The mold is placed in the furnace, and the pressure in the furnace is vacuumed to below -0.01 MPa. Ar gas is introduced as a protective gas, and the flow rate is set to 1 L / min. The temperature is raised to 1060℃ at a rate of 5-8℃ / min. Then introduce methane, set the flow rate to 0.6 L / min, and the argon flow rate to 2.4 L / min, the methane to argon flow ratio is 1:4. After 20 h of heat preservation, the furnace is cooled down, and a dense C / C-W composite material with a porosity of 24.66% is obtained.

[0053] Example 3:

[0054] The preparation method of tungsten modified C / C composite material in this embodiment includes the following steps:

[0055] S1: take W powder and anhydrous ethanol in a weight ratio of 1:4 in a beaker, and stir with a magnetic stirrer at room temperature for 2 h to form a suspension;

[0056] S2: ultrasonic clean the C / C composite material with a density of 1.1 g / cm 3 , and put it into a 70℃ oven to dry for 10 h;

[0057] S3: build a vacuum filtration device, the sample (xy surface up) after drying S2 placed on the filter membrane. With a pipette extract slurry into the sample surface, control the uniform distribution of powder on the surface. Until the surface can not be extracted into the W powder. Remove the sample, with anhydrous ethanol flush away the surface powder, in 80℃ oven drying 10 h after weighing.

[0058] S4: repeat S3 step until the sample weight gain is no longer obvious.

[0059] S5: The composite material obtained in S4 is fixed in a mold of a small chemical vapor deposition furnace. The mold is placed in the furnace, and vacuum is drawn to below -0.01 MPa. Ar gas is introduced as a protective gas, and the flow rate is set to 1 L / min. The temperature is raised to 1070°C at a rate of 5-8°C / min. Then, methane is introduced, and the flow rate is set to 0.6 L / min, and the argon flow rate is set to 2.4 L / min, and the methane to argon flow rate ratio is 1:4. After 30 h of heat preservation, the furnace is cooled, and a dense C / C-W composite material is obtained, and the porosity is 23.07%.

[0060] Example 4:

[0061] The preparation method of the tungsten modified C / C composite material in this example includes the following steps:

[0062] S1: W powder and anhydrous ethanol are weighed in a weight ratio of 1:4 in a beaker, and stirred at room temperature for 2 h using a magnetic stirrer to form a suspension;

[0063] S2: The C / C composite material with a density of 1.3 g / cm 3 is cleaned by ultrasonic cleaning and placed in a 70°C oven for drying for 10 h;

[0064] S3: A vacuum filtration device is built, and the sample after drying in S2 (xy plane upward) is placed on the filter membrane. The slurry is dropped onto the surface of the sample using a pipette, and the powder is uniformly distributed on the surface. This process is repeated until no more W powder can be drawn into the surface. The sample is removed, and the residual powder on the surface is washed off with anhydrous ethanol. After drying in a 70°C oven for 12 h, the sample is weighed.

[0065] S4: The step S3 is repeated until the weight gain of the sample is no longer obvious.

[0066] S5: The composite material obtained in S4 is fixed in a mold of a small chemical vapor deposition furnace. The mold is placed in the furnace, and vacuum is drawn to below -0.01 MPa. Ar gas is introduced as a protective gas, and the flow rate is set to 1 L / min. The temperature is raised to 1070°C at a rate of 5-8°C / min. Then, methane is introduced, and the flow rate is set to 0.6 L / min, and the argon flow rate is set to 2.4 L / min, and the methane to argon flow rate ratio is 1:4. After 30 h of heat preservation, the furnace is cooled, and a dense C / C-W composite material is obtained, and the porosity is 23.07%.

[0067] Example 5:

[0068] The preparation method of the tungsten modified C / C composite material in this example includes the following steps:

[0069] S1: W powder and anhydrous ethanol were weighed according to a weight ratio of 3:10, placed in a beaker, and stirred at room temperature with a magnetic stirrer for 1 h to form a suspension;

[0070] S2: C / C composite material with a density of 1.0 g / cm 3 was ultrasonically cleaned and placed in an 80°C oven for drying for 10 h;

[0071] S3: A vacuum filtration device was set up, and the sample dried in S2 (xy plane facing up) was placed on the filter membrane. The slurry was dropped onto the surface of the sample with a pipette to control the uniform distribution of the powder on the surface. This was repeated until no W powder could be drawn into the surface. The sample was removed, and the surface was washed with anhydrous ethanol to remove the remaining powder. The sample was dried in an 80°C oven for 10 h and weighed.

[0072] S4: The S3 step was repeated until the weight gain of the sample was no longer obvious.

[0073] S5: The composite material obtained in S4 was fixed in a mold of a small chemical vapor deposition furnace. The mold was placed in the furnace, and the furnace was evacuated to a pressure of -0.01 MPa or lower. Ar gas was introduced as a protective gas, and the flow rate was set to 1 L / min. The temperature was raised to 1030°C at a rate of 5-8°C / min. Then, methane was introduced, and the flow rate was set to 0.6 L / min, and the argon flow rate was set to 2.4 L / min, with a methane to argon flow ratio of 1:4. After 30 h of heat preservation, the furnace was cooled, and a dense C / C-W composite material was obtained, with a porosity of 24.15%.

[0074] Comparative Example 1:

[0075] This comparative example includes the following processes:

[0076] The other conditions of this comparative example were the same as those of Example 1, except that a C / C composite material with a density of 1.4 g / cm 3 was selected in S2. Due to its low porosity and small pores, the 3-5 μm W powder could not be introduced into the surface of the matrix to form a coating. As shown in FIG. 1, the depth of W in the C / C composite material matrix was only 40 μm, and a continuous W layer could not be formed. Figure 5

[0077] Comparative Example 2:

[0078] This comparative example includes the following processes:

[0079] The other conditions of this comparative example were the same as those of Example 2, except that the temperature of the small chemical vapor deposition furnace was raised to 950 o C in S5, and the carbon deposition was performed for 20 h. The porosity of the obtained sample was 37.33% as measured by the Archimedes drainage method, indicating that the carbon deposition effect was poor at this temperature. ​

[0080] Comparative Example 3:

[0081] The present comparative example includes the following process:

[0082] The other conditions of the present comparative example are the same as those of Example 2, except that in S5, the temperature of the small chemical vapor deposition furnace is raised to 1100 o C, and carbon deposition is performed for 20 h. As shown in FIG. 4, part of the metal W on the surface layer of the sample has reacted with the substrate C to form WC. Figure 6

[0083] From the results of the above examples and comparative examples, it can be seen that to prepare the C / C-W composite material, first, a C / C composite material having a density of 1.0-1.3 g / cm 3 is used to perform filtration to obtain a first composite structure. The C / C composite material in this density range has many pores, which can provide space for the introduction of W powder. In the chemical vapor infiltration process, an appropriate temperature range is used to control the efficiency of the deposition of pyrolytic carbon as high as possible and to avoid a large amount of chemical reaction between W and C, so as to ensure that the W element exists in the form of metal inside the C / C composite material.

[0084] Obviously, the described examples are only part of the embodiments of the present application, rather than all the embodiments. Based on the examples in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor should belong to the scope of protection of the present application.

[0085] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, but not to limit it. Although the present application has been described in detail with reference to the above examples, those of ordinary skill in the art should understand that the specific embodiments of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the present application, and any modification or equivalent replacement without departing from the spirit and scope of the present application should be covered in the protection scope of the claims of the present application.​

Claims

1. A method for producing a tungsten-modified C / C composite material, characterized by, The process comprises the following steps: The C / C composite material is placed on a filter membrane, and a suspension of tungsten powder is suction filtered to obtain a first composite structure of tungsten powder and the C / C composite material, and the first composite structure is dried; the particle size of the tungsten powder is 3-5 μm, and the density of the C / C composite material is 1.0-1.3 g / cm 3 When suction filtering, the C / C composite material net tire layer and the no-woven cloth layer are alternately distributed and arranged with the surface facing upward. The carbon deposition densification of the dried first composite structure is carried out to obtain the tungsten modified C / C composite material, which comprises the following steps: in a protective atmosphere, pyrolytic carbon is deposited on the surface of the dried first composite structure by using methane gas to realize the carbon deposition densification of the first composite structure; wherein the temperature during the deposition of the pyrolytic carbon is 1030-1070℃, and the time is 20-30h; after the deposition is completed, the temperature is first reduced to 300℃, and then the furnace is cooled.

2. The method for preparing a tungsten-modified C / C composite material according to claim 1, characterized in that, During the filtration, the filtration is carried out until the surface of the C / C composite material cannot be filtered into the suspension liquid, and then drying is carried out.

3. The method for preparing a tungsten-modified C / C composite material according to claim 2, characterized in that, The process further comprises the following steps: The process of placing the dried first composite structure on the filter membrane, filtering the suspension liquid of the tungsten powder and drying the first composite structure is repeated until the first composite structure does not increase in weight.

4. The method for preparing a tungsten-modified C / C composite material according to claim 2, characterized in that, Before the first composite structure of the tungsten powder and the C / C composite material is dried, the residual powder on the surface of the first composite structure is washed away by using anhydrous ethanol, and then drying is carried out.

5. The method for preparing a tungsten-modified C / C composite material according to claim 1, characterized in that, In the suspension liquid of the tungsten powder, the solvent is anhydrous ethanol, and the mass ratio of the tungsten powder to the anhydrous ethanol is 1: (3-4); when the first composite structure is dried, the drying temperature is 70-80℃, and the drying time is 10-12h.

6. The method for preparing a tungsten-modified C / C composite material according to claim 1, characterized in that, The process further comprises the following steps: the C / C composite material is first cleaned and pretreated, and the C / C composite material after the cleaning and pretreatment is filtered; When the C / C composite material is cleaned and pretreated, the C / C composite material is ultrasonically cleaned, and then dried at 60-80℃ for 10-12h.

7. A tungsten-modified C / C composite material, characterized by, The tungsten modified C / C composite material is prepared by the preparation method of any one of claims 1-6.

Images