Carbide and boride ultrahigh-temperature ceramic modified C / C composite material and preparation method thereof

Abstract

The invention discloses a carbide and boride ultrahigh-temperature ceramic modified C / C composite material and a preparation method thereof.The preparation method comprises the steps that methyl alcohol is added into phenolic resin, and a phenolic resin solution is obtained; then adding benzoyl chloride and boric acid to obtain a precursor solution; putting the dried C / C composite material into the precursor solution for dipping, carrying out curing, drying and carbon thermal reduction reaction together with the precursor solution, and repeating for a plurality of times to obtain a porous B4C-C / C composite material; and completely wrapping the porous B4C-C / C composite material with HfSi2 powder, carrying out heating infiltration in a vacuum environment, and carrying out heat preservation to obtain the C / C-HfC-HfB2-SiC composite material. According to the preparation method, in-situ reaction in the material is facilitated to generate uniformly distributed boride ceramic and carbide ceramic, so that B4C and alloy residues after reaction infiltration are avoided, and the ablation resistance is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of modified C / C composite material, and relates to a carbide and boride ultrahigh-temperature ceramic modified C / C composite material and a preparation method thereof. BACKGROUND

[0002] C / C composite material has low density, low thermal expansion coefficient, ablation resistance and good mechanical properties, especially at high temperature, the strength of C / C composite material does not decrease but increases with the increase of temperature, and the C / C composite material is an indispensable key material for advanced aerospace vehicles and their power systems. However, the oxidation and ablation problem of C / C composite material in a high-temperature high-speed particle erosion environment seriously restricts its application, and therefore improving the anti-oxidation and ablation performance of C / C composite material is a key to its application in a high-temperature environment. At present, the matrix modification technology is one of the main measures to improve the ablation resistance of C / C composite material. Among the many matrix modification technologies, the reaction melt infiltration process has the advantages of high densification efficiency, short production cycle, net size forming and the like, and therefore has a wide application.

[0003] In the literature "Liu Z, Sun Y, Zhang S, et al. Microstructure and ablation resistance of C / C-HfC-SiC composites prepared by RMI with different powder particle sizes[J]. Materials Characterization, 2024, 218: 114577.", the infiltration alloy used is HfSi2 powder, and a C / C-HfC-SiC composite material is prepared by a reaction melt infiltration method, which exhibits good ablation resistance after ablation at a temperature of about 2500 DEG C for 40s. Among them, the carbide ceramic introduced by the process is obtained by carbothermal reduction reaction of molten alloy and pyrolytic carbon in the C / C preform. Since the material only contains carbon, the above method can only obtain carbide ceramics.

[0004] The boride ceramic has a high melting point and excellent ablation resistance comparable to the carbide, and has a higher thermal conductivity, which helps to reduce the ablation temperature at the stagnation point of sharp components, and the preparation of the C / C composite material modified by the combination of boride and carbide ceramic is conducive to further improving the ablation resistance.

[0005] In the literature "Liu Y, Fu Q, Wang B, et al. The ablation behavior and mechanical property of C / C-SiC-ZrB2 composites fabricated by reactive melt infiltration[J]. Ceramics International, 2017, 43(8): 6138-6147.", C / C-SiC-ZrB2 composites were prepared by infiltrating B4C, ZrSi2 and C powders into C / C preform, and after ablation for 60 s under an oxyacetylene flame with a heat flux of 2.38 MW / m 2 , the mass ablation rate was 0.6 mg / s, and the material had excellent ablation resistance.

[0006] However, the C / C-SiC-ZrB2 composites prepared by this method have unreacted B4C inside, and the boride ceramic is not uniformly distributed. In addition, the uneven pore structure of the C / C preform affects the infiltration behavior of the melt, and the alloy melt in the large pores between the fiber bundles cannot fully react, resulting in the presence of residual alloy, which limits the further improvement of the performance of the composite material. SUMMARY

[0007] The purpose of the present application is to provide a carbide and boride ultra-high temperature ceramic modified C / C composite material and a preparation method thereof, which solves the problems of B4C residue, alloy residue and uneven distribution of boride ceramic in the existing boride modified C / C composite material.

[0008] To achieve the above-mentioned purpose, the technical scheme is adopted as follows: A preparation method of a carbide and boride ultra-high temperature ceramic modified C / C composite material, comprising: adding methanol to the phenolic resin to obtain a phenolic resin solution; adding benzoyl chloride and boric acid to the phenolic resin solution to obtain a precursor solution; immersing the dry C / C composite material in the precursor solution, and performing curing, drying and carbothermal reduction reaction with the precursor solution to obtain a porous B4C-C / C composite material; repeating the immersion, curing, drying and carbothermal reduction reaction several times to control the pore structure of the porous B4C-C / C composite material; completely wrapping the porous B4C-C / C composite material with HfSi2 powder, and heating and infiltrating in a vacuum environment to obtain a C / C-HfC-HfB2-SiC composite material.

[0009] Further, the mass ratio of the phenolic resin and the methanol is 1:0.5-4, the mass of the benzoyl chloride is 5%-20% of the mass of the phenolic resin solution, and the mass ratio of the phenolic resin and the boric acid is 1:0.3-0.8.

[0010] Further, the density of the C / C composite material is 0.6-1.3 g / cm 3 .

[0011] Further, the impregnation time of the C / C composite material in the precursor solution is 10-40 min.

[0012] Further, the curing temperature is 120-200 DEG C, and the curing time is 2-10 h.

[0013] Further, the drying temperature is 50-100 DEG C, and the drying time is 6-12 h.

[0014] Further, the carbon thermal reduction reaction process comprises: Under an argon atmosphere, the impregnated C / C composite material is placed in a tube furnace to undergo a carbon thermal reduction reaction, is heated to 800-1200 DEG C at a heating rate of 3-10 DEG C / min, is kept at the temperature for 0.5-2 h, is then heated to 1400-1600 DEG C at a heating rate of 3-10 DEG C / min, is kept at the temperature for 0.5-2 h, is cooled to room temperature at a cooling rate of less than or equal to 4 DEG C / min after the reaction is completed, and a porous B4C-C / C composite material for a melt infiltration process is obtained.

[0015] Further, the number of times of repeating the impregnation, the curing, the drying and the carbon thermal reduction reaction is 1-6.

[0016] Further, the process of heating and melt infiltrating comprises: Under a vacuum degree of 1-10 Pa, the temperature is raised to 1600-2000 DEG C at a heating rate of 5-10 DEG C / min, is kept at the temperature for 1-3 h, and is then cooled to room temperature at a cooling rate of less than or equal to 4 DEG C / min, and a C / C-HfC-HfB2-SiC composite material is obtained.

[0017] A carbide and boride ultra-high temperature ceramic modified C / C composite material is prepared by using the preparation method.

[0018] Compared with the prior art, the present application has the following beneficial effects: The application provides a preparation method of carbide and boride ultrahigh-temperature ceramic modified C / C composite material, which comprises the following steps: taking phenolic resin, methanol, benzoyl chloride and boric acid as raw materials, mixing uniformly to prepare a precursor solution; then, putting C / C composite material into the precursor solution for impregnation, and then performing solidification, drying and carbothermal reduction reaction to obtain porous B4C-C / C composite material; and then, performing reaction infiltration of silicide powder and the porous B4C-C / C composite material in a vacuum environment to obtain the carbide and boride ultrahigh-temperature ceramic modified C / C composite material. The application has the advantages of simple technological process, short preparation period, introduction of porous spherical structure B4C into the inside of C / C composite material, filling of B4C in the form of porous spherical structure into the larger pores in the inside of C / C preform, optimization of the pore structure of the C / C preform, realization of the regulation and optimization of the pore structure of the material, effective shortening of the diffusion distance of carbon atoms and boron atoms to the inside of the molten alloy, avoidance of the B4C and alloy residues in the inside of the ultrahigh-temperature ceramic modified C / C composite material prepared after reaction infiltration, and facilitation of the uniform distribution of the carbide and boride ultrahigh-temperature ceramic in the inside of the C / C composite material, so as to guarantee the ablation resistance of the C / C composite material. In addition, the porous spherical structure B4C has a large specific surface area, can increase the contact area with the molten alloy, is beneficial to the full reaction, the raw materials used in the application are low in price, so that the cost can be effectively saved, the efficiency is high, and the application has the potential for large-scale industrial production. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some of the embodiments of the application, and therefore should not be regarded as a limitation to the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0020] Figure 1 XRD patterns of the precursor solution after carbothermal reduction reaction in Examples 1-3 of the application.

[0021] Figure 2 XRD patterns of the porous B4C-C / C composite material in Examples 1-3 of the application and the C / C composite material without impregnation treatment in Comparative Example 1, wherein the diffraction angle 2θ range of the (a) graph is 10°-90°, and the (b) graph is an enlarged view of the (a) graph in the range of 30°-50°.

[0022] Figure 3SEM images of the porous B4C-C / C composite material in Examples 1-3 of the present application, wherein (a) is an SEM image of the product after the precursor solution is solidified and subjected to a carbothermal reduction reaction in Example 1, (b) is a cross-sectional view of the porous B4C-C / C composite material after impregnation three times in Example 1, (c) is a cross-sectional view of the porous B4C-C / C composite material after impregnation two times in Example 2, and (d) is a cross-sectional view of the porous B4C-C / C composite material after impregnation four times in Example 3.

[0023] Figure 4 XRD pattern of the C / C composite material modified by ultra-high temperature ceramics in Example 1 and Comparative Example 1 of the present application.

[0024] Figure 5 Cross-sectional BSD photo and EDS spectrum of the C / C-HfC-HfB2-SiC composite material prepared in Example 1 of the present application.

[0025] Figure 6 Surface macrograph of the C / C-HfC-HfB2-SiC composite material before and after ablation in Example 1 of the present application, wherein (a) is a surface macrograph before ablation, and (b) is a surface macrograph after ablation. DETAILED DESCRIPTION

[0026] To enable persons skilled in the art to understand the features and effects of the present application, the following is a general description and definition of the terms and phrases mentioned in the specification and claims. Unless otherwise specified, all technical and scientific words used herein have their usual meanings to those skilled in the art of the present application, and in the event of conflict, the definitions in the present specification shall prevail.

[0027] Theories or mechanisms described and disclosed herein, whether correct or not, should not be considered limiting on the scope of the present application, i.e., the present application can be practiced without regard to any particular theory or mechanism.

[0028] Herein, all features defined in the form of numerical ranges or percentage ranges, such as numerical values, amounts, contents and concentrations, are for the sake of brevity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be considered to have encompassed and specifically disclosed all possible sub-ranges and individual numerical values within the range (including integers and fractions).

[0029] Herein, unless otherwise specified, “comprise”, “include”, “contain”, “have” or similar words encompass the meaning of “consist of” and “consist essentially of”, for example, “A comprises a” encompasses the meaning of “A comprises a and other” and “A comprises only a”.

[0030] Herein, all possible combinations of the various technical features in the various embodiments or examples are not described in order to make the description concise. Therefore, as long as there is no contradiction in the combination of the technical features, the technical features in the various embodiments or examples can be combined arbitrarily, and all possible combinations shall be considered as the scope of the description.

[0031] The application will be further described in conjunction with specific examples. It should be understood that these examples are only used to illustrate the application and not used to limit the scope of the application. Furthermore, it should be understood that those skilled in the art can make various modifications or changes to the application after reading the content taught by the application, and these equivalent forms also fall within the scope defined by the claims of the application.

[0032] The following examples use the conventional apparatus in the art. The experimental method in the following examples is not specified, which is usually carried out according to the conventional conditions, or according to the conditions recommended by the manufacturer. Various raw materials are used in the following examples, unless otherwise specified, and the conventional commercially available products are used, which are the conventional specifications in the art. In the specification of the application and the following examples, unless otherwise specified, “%” means weight percent, “parts” means weight parts, and the ratio means weight ratio.

[0033] The application will be further described in conjunction with specific examples. It should be understood that these examples are only used to illustrate the application and not used to limit the scope of the application. Furthermore, it should be understood that those skilled in the art can make various modifications or changes to the application after reading the content taught by the application, and these equivalent forms also fall within the scope defined by the claims of the application. The application provides a preparation method of carbide and boride ultrahigh-temperature ceramic modified C / C composite material, which specifically comprises the following steps: Step 1: phenolic resin is added with methanol to mix uniformly to obtain a phenolic resin solution, benzoyl chloride and boric acid are added to the phenolic resin solution to mix uniformly to obtain a precursor solution.

[0034] Preferably, the mass ratio of phenolic resin to methanol is 1:0.5-4, the mass of benzoyl chloride is 5%-20% of the mass of the phenolic resin solution, and the mass ratio of phenolic resin to boric acid is 1:0.3-0.8.

[0035] The stirring time for mixing the phenolic resin with methanol at room temperature is 15-60 min, and the stirring time for mixing benzoyl chloride and boric acid in the phenolic resin solution at room temperature is 15-60 min.

[0036] Step 2: the C / C composite material is cleaned and dried, the dried C / C composite material is put into the precursor solution for impregnation, and the precursor solution is subjected to solidification, drying and carbothermal reduction reaction to obtain a porous B4C-C / C composite material, and the impregnation, solidification, drying and carbothermal reduction reaction are repeated multiple times to realize the regulation of the pore structure of the porous B4C-C / C composite material.

[0037] Preferably, the density of the used C / C composite material is 0.6-1.3 g / cm 3 .

[0038] The impregnation time of the C / C composite material in the precursor solution is 10-40 min.

[0039] The curing temperature is 120-200℃, and the curing time is 2-10 h.

[0040] The drying temperature is 50-100℃, and the drying time is 6-12 h.

[0041] After impregnation, the C / C composite material is placed in a tube furnace under an argon atmosphere, heated to 800-1200℃ at a heating rate of 3-10℃ / min, held for 0.5-2 h, then heated to 1400-1600℃ at a heating rate of 3-10℃ / min, held for 0.5-2 h, and after the reaction is complete, cooled to room temperature at a cooling rate of not more than 4℃ / min. The above impregnation, curing, drying and carbothermal reduction reaction are repeated 1-6 times to obtain a porous B4C-C / C composite material for infiltration process.

[0042] Step 3: A layer of HfSi2 powder is laid at the bottom of a graphite crucible, the porous B4C-C / C composite material is placed in the graphite crucible, and HfSi2 powder is added to completely wrap the porous B4C-C / C composite material. The C / C-HfC-HfB2-SiC composite material is obtained after heating and infiltration in a vacuum environment for a holding time.

[0043] Specifically, after the HfSi2 powder and the porous B4C-C / C composite material are placed in the graphite crucible, heating and infiltration are carried out in a vacuum environment, the vacuum degree is 1-10 Pa, the temperature is raised to 1600-2000℃ at a heating rate of 5-10℃ / min, and the holding time is 1-3 h. Then, the temperature is lowered to room temperature at a cooling rate of not more than 4℃ / min to obtain the C / C-HfC-HfB2-SiC composite material.

[0044] The technical solutions of the present application are further described in detail through specific examples as follows: Example 1: Step 1: Phenolic resin and methanol are weighed according to a mass ratio of 1:1.8, stirred at room temperature with a magnetic stirrer for 20 min, and uniformly mixed to obtain a phenolic resin solution. Then, benzoyl chloride and boric acid are added to the phenolic resin solution, the mass of benzoyl chloride is 5% of the mass of the phenolic resin solution, and the mass ratio of phenolic resin to boric acid is 1:0.55. The mixture is stirred at room temperature with a magnetic stirrer for 30 min, and uniformly mixed to obtain a precursor solution.

[0045] Step 2: The C / C composite material with a density of 1.08 g / cm 3The C / C composite material was ultrasonically cleaned and dried in an 80°C oven for 8h. The dried C / C composite material was immersed in the precursor solution for 15min and cured in the precursor solution in a 160°C oven for 5h. The cured C / C composite material was then dried in an 80°C oven for 6h. The dried C / C composite material was then placed in a tube furnace and heated to 1000°C at a heating rate of 8°C / min under an argon atmosphere, held for 1h, heated to 1500°C at a heating rate of 5°C / min, held for 1h, and then cooled to room temperature at a cooling rate of 4°C / min to obtain a porous B4C-C / C composite material. The above steps of immersion, curing, drying, and carbothermal reduction were repeated three times to obtain a porous B4C-C / C composite material for infiltration.

[0046] Step 3: A layer of HfSi2 powder was laid on the bottom of a graphite crucible, and the porous B4C-C / C composite material was placed in the graphite crucible and completely wrapped with the HfSi2 powder. The wrapped porous B4C-C / C composite material was placed in a vacuum hot pressing furnace and infiltrated at a heating rate of 8°C / min to 1800°C, with a holding time of 2h and a vacuum degree of 5Pa during the holding period. The temperature was then decreased to room temperature at a cooling rate of 4°C / min to obtain a C / C-HfC-HfB2-SiC composite material.

[0047] Example 2: Step 1: Phenol formaldehyde resin and methanol were weighed in a mass ratio of 1:2 and stirred at room temperature with a magnetic stirrer for 30min. After mixing, a phenol formaldehyde resin solution was obtained. Benzoyl chloride and boric acid were then added to the phenol formaldehyde resin solution. The mass of benzoyl chloride was 9% of the mass of the phenol formaldehyde resin solution, and the mass ratio of phenol formaldehyde resin to boric acid was 1:0.68. The mixture was stirred at room temperature with a magnetic stirrer for 30min. After mixing, a precursor solution was obtained.

[0048] Step 2: The C / C composite material with a density of 1.15g / cm 3 The C / C composite material was ultrasonically cleaned and dried in an 80°C oven for 8h. The dried C / C composite material was immersed in the precursor solution for 25min and cured in the precursor solution in a 180°C oven for 4h. The cured C / C composite material was then dried in an 80°C oven for 10h. The dried C / C composite material was then placed in a tube furnace and heated to 1200°C at a heating rate of 9°C / min under an argon atmosphere, held for 0.8h, heated to 1500°C at a heating rate of 4°C / min, held for 2h, and then cooled to room temperature at a cooling rate of 4°C / min to obtain a porous B4C-C / C composite material. The above steps of immersion, curing, drying, and carbothermal reduction were repeated twice to obtain a porous B4C-C / C composite material for infiltration.

[0049] Step 3: Put a layer of HfSi2 powder on the bottom of the graphite crucible, put the porous B4C-C / C composite material into the graphite crucible, and then add HfSi2 powder to completely wrap the porous B4C-C / C composite material. Put it into a vacuum hot pressing furnace for infiltration, heat it to 1700°C at a heating rate of 8°C / min, and keep it for 2h. The vacuum degree during the holding period is 6Pa. Then, reduce it to room temperature at a cooling rate of 4°C / min. C / C-HfC-HfB2-SiC composite material is obtained.

[0050] Example 3: Step 1: Take phenolic resin and methanol according to a mass ratio of 1:2.5, stir them at room temperature with a magnetic stirrer for 40min, and then mix them uniformly to obtain a phenolic resin solution. Then add benzoyl chloride and boric acid to the phenolic resin solution. The mass of benzoyl chloride is 11% of the mass of the phenolic resin solution, and the mass ratio of phenolic resin to boric acid is 1:0.46. Stir them at room temperature with a magnetic stirrer for 30min, and then mix them uniformly to obtain a precursor solution.

[0051] Step 2: Clean the C / C composite material with a density of 1.1g / cm 3 in an ultrasonic cleaner, and then dry it in an 80°C oven for 8h. Put the dried C / C composite material into the precursor solution, immerse it for 30min, and then solidify it together with the precursor solution in a 150°C oven for 8h. Then dry the C / C composite material after the solidification treatment in an 80°C oven for 6h. Then put it into a tube furnace, heat it to 900°C at a heating rate of 6°C / min in an argon atmosphere, keep it for 1h, heat it to 1550°C at a heating rate of 4°C / min, keep it for 1h, and then reduce it to room temperature at a cooling rate of 4°C / min. A porous B4C-C / C composite material is obtained. Repeat the above immersion, solidification, drying, and carbothermal reduction reaction four times to obtain a porous B4C-C / C composite material for infiltration process.

[0052] Step 3: Put a layer of HfSi2 powder on the bottom of the graphite crucible, put the porous B4C-C / C composite material into the graphite crucible, and then add HfSi2 powder to completely wrap the porous B4C-C / C composite material. Put it into a vacuum hot pressing furnace for infiltration, heat it to 1700°C at a heating rate of 8°C / min, and keep it for 2h. The vacuum degree during the holding period is 6Pa. Then, reduce it to room temperature at a cooling rate of 4°C / min. C / C-HfC-HfB2-SiC composite material is obtained.

[0053] Comparative Example 1: Clean the C / C composite material with a density of 1.2g / cm 3The C / C composite material cleaned by ultrasonic cleaning is dried in an 80℃ oven for 8h, and is used for subsequent infiltration. A layer of HfSi2 powder is laid at the bottom of a graphite crucible, the dried C / C composite material is put into the graphite crucible, and HfSi2 powder is added to completely wrap the porous C / C composite material. The wrapped material is put into a vacuum hot pressing furnace for infiltration, the temperature is raised to 1800℃ at a rate of 10℃ / min, the holding time is 2h, the vacuum degree is 5Pa during the holding time, and then the temperature is lowered to room temperature at a rate of 4℃ / min, thereby obtaining a C / C-HfC-SiC composite material, which does not contain boride ceramic.

[0054] The processes and products of the C / C-HfC-HfB2-SiC composite materials prepared in Examples 1-3 and the C / C-HfC-SiC composite material prepared in Comparative Example 1 are tested for performance: As shown in Figure 1 FIG. 1, the XRD pattern of the porous B4C obtained by the carbothermal reduction reaction of the precursor solution solidified together with the C / C composite material after impregnation in Examples 1-3, it can be seen from the figure that, in Example 1, there are diffraction peaks of B4C near 19.7°, 21.9°, 23.4°, 31.9°, 34.8°, 37.7°, 53.3°, 63.5°, 64.2° and 66.6°, and steamed bun peaks appear near 26° and 42°, which correspond to the diffraction peak positions of graphite (002) and (101) planes, respectively, indicating that the material also contains C; in Example 2 and Example 3, there are diffraction peaks of B4C and C.

[0055] As shown in Figure 2 , FIG. 2, Figure 2 (a) is the XRD pattern of the porous B4C-C / C composite material in Examples 1-3 and the C / C composite material without impregnation treatment in Comparative Example 1, the diffraction angle 2θ ranges from 10° to 90°, it can be seen from the figure that, in Examples 1-3, there are diffraction peaks of C and B4C, in Comparative Example 1, there is only a diffraction peak of C, and there is no diffraction peak of B4C. Figure 2 (b) is an enlarged view of the 30°-50° interval of the graph in (a), the diffraction peaks of B4C can be more obviously observed in Examples 1-3, indicating that B4C is successfully introduced into the C / C composite material; in Comparative Example 1, there is only a diffraction peak of C, and there is no diffraction peak of B4C.

[0056] As shown in Figure 3 , FIG. 3, Figure 3 (a) is the SEM graph of the porous B4C obtained by solidifying the precursor solution and the carbothermal reduction reaction in Example 1, the porous B4C presents a spherical boron carbide particle structure, and the pore structure is uniform. Figure 3 (b) is a cross-sectional view of the porous B4C-C / C composite material after impregnation three times in Example 1, it can be seen from the figure that, the porous B4C-C / C composite material is uniformly wrapped by the B4C layer, and the B4C layer is not separated from the C / C composite material. Figure 3As can be seen in (b), B4C was successfully impregnated into the interior of the C / C composite material. B4C is still spherical and cross-linked in the material interlayer and large-scale pore regions, breaking up the large pores inside the C / C preform and optimizing the pore structure of the material. Figure 3 (c) is a cross-sectional view of the porous B4C-C / C composite material after two impregnations in Example 2. It can be seen from the figure that the reduction in the number of impregnations leads to a decrease in the amount of B4C impregnated in the material, indicating that the number of impregnations can adjust the pore structure of the C / C preform. Figure 3 (d) is a cross-sectional view of the porous B4C-C / C composite material after four impregnations in Example 3. It can be seen from the figure that the B4C content in the material increases with the increase of the number of impregnations. Therefore, by changing the number of impregnations, the pore structure of the C / C preform can be adjusted and optimized.

[0057] like Figure 4 The figure shows the XRD patterns of the C / C-HfC-HfB2-SiC composite material prepared in Example 1 and the C / C-HfC2-SiC composite material prepared in Comparative Example 1. It can be observed from the figure that diffraction peaks of C, SiC, HfC, and HfB2 are present in Example 1, indicating that boride ceramics were successfully introduced into the C / C composite material, thus preparing the C / C-HfC-HfB2-SiC composite material. Furthermore, no diffraction peaks of silicide alloys are present in the figure, indicating that there are no residual alloy compounds inside the material. Comparative Example 1 shows the presence of C, SiC, HfC, and HfB2. x Si y The absence of HfB2 diffraction peaks indicates that boride ceramics are not present inside the C / C composite material. Therefore, a C / C composite material modified with carbide and boride ultra-high temperature ceramics was not successfully prepared, and the molten HfSi2 alloy did not react completely, thus containing Hf... x Si y Alloy residue.

[0058] like Figure 5 The image shows the cross-sectional BSD and EDS spectra of the C / C-HfC-HfB2-SiC composite material prepared in Example 1. It can be seen that SiC, HfC and HfB2 ceramics are uniformly distributed inside the material.

[0059] like Figure 6 As shown, Figure 6 (a) A macroscopic image of the C / C-HfC-HfB2-SiC composite material prepared in Example 1 after grinding, cleaning, and drying, at 2.4 MW / m 2 An ablation test was performed on it for 120 seconds at a heat flux density, and the macroscopic image after ablation is shown below. Figure 6(b) The sample after ablation shows good structural integrity, and the surface is covered with continuous oxidation products without obvious ablation pits. The mass ablation rate is 1.83 mg / s, and the linear ablation rate is -1.68 μm / s.

[0060] The above merely illustrates the preferred embodiments of the present application, but is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing a carbide and boride ultra-high temperature ceramic modified C / C composite material, characterized in that, The method comprises the following steps: adding methanol into the phenolic resin to obtain a phenolic resin solution; adding benzoyl chloride and boric acid into the phenolic resin solution to obtain a precursor solution; immersing the dried C / C composite material into the precursor solution, and performing solidification, drying and carbothermal reduction reaction on the precursor solution to obtain a porous B4C-C / C composite material; controlling the pore structure of the porous B4C-C / C composite material by repeating the steps of immersion, solidification, drying and carbothermal reduction reaction for several times; completely wrapping the porous B4C-C / C composite material with HfSi2 powder, and performing heating and sintering in a vacuum environment to obtain a C / C-HfC-HfB2-SiC composite material.

2. The method for preparing carbide and boride ultra-high temperature ceramic modified C / C composite material according to claim 1, characterized in that, The mass ratio of the phenolic resin to the methanol is 1: (0.5-4), the mass of the benzoyl chloride is 5%-20% of the mass of the phenolic resin solution, and the mass ratio of the phenolic resin to the boric acid is 1: (0.3-0.8).

3. The method of claim 1, wherein the method is characterized by: The density of the C / C composite material is 0.6-1.3 g / cm 3 .

4. The method of claim 1, wherein the method is characterized by: The immersion time of the C / C composite material in the precursor solution is 10-40 min.

5. The method of claim 1, wherein the method is characterized by: The solidification temperature is 120-200 DEG C, and the solidification time is 2-10 h.

6. The method of claim 1, wherein the method is characterized by: The drying temperature is 50-100 DEG C, and the drying time is 6-12 h.

7. The method of claim 1, wherein the method is characterized by: The carbothermal reduction reaction process comprises the following steps: placing the immersed C / C composite material in a tube furnace to perform carbothermal reduction reaction in an argon atmosphere, heating to 800-1200 DEG C at a heating rate of 3-10 DEG C / min, keeping the temperature for 0.5-2 h, then heating to 1400-1600 DEG C at a heating rate of 3-10 DEG C / min, keeping the temperature for 0.5-2 h, and then cooling to room temperature at a cooling rate of less than or equal to 4 DEG C / min to obtain the porous B4C-C / C composite material for sintering process.

8. The method of claim 1, wherein the method is characterized by: The number of times of repeating the steps of immersion, solidification, drying and carbothermal reduction reaction is 1-6.

9. The method of claim 1, wherein the method is characterized by: The heating and sintering process comprises the following steps: heating to 1600-2000 DEG C at a heating rate of 5-10 DEG C / min under a vacuum degree of 1-10 Pa, keeping the temperature for 1-3 h, and then cooling to room temperature at a cooling rate of less than or equal to 4 DEG C / min to obtain the C / C-HfC-HfB2-SiC composite material.

10. A carbide and boride ultra-high temperature ceramic modified C / C composite material prepared by the method in any one of claims 1-9.

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