Ablation-resistant ultrahigh-temperature ceramic-based composite material and preparation method thereof

Abstract

The invention relates to an ablation-resistant ultrahigh-temperature ceramic matrix composite material and a preparation method thereof. The method comprises the following steps: depositing pyrolytic carbon on the surface of a carbon fiber preform through a CVD method; preparing a silicon carbide interface layer on the surface of the pyrolytic carbon through a CVD method; carrying out a reaction with a matrix containing a pyrolytic carbon-silicon carbide composite interface layer through an impregnation pyrolysis method; a zirconium carbide coating is prepared on the surface of the composite material matrix through a CVD method; and preparing a zirconium oxide coating on the surface of the zirconium carbide coating through an atomic layer deposition method, and carrying out ultra-fast annealing treatment to prepare the ablation-resistant ultra-high-temperature ceramic-based composite material. The zirconium carbide-zirconium oxide composite coating is prepared by combining chemical vapor deposition and atomic layer deposition and relying on ultra-fast annealing treatment, the zirconium oxide coating is high in compactness and can more effectively protect a matrix, and a pyrolytic carbon-silicon carbide composite interface layer is introduced to achieve effective protection of carbon fibers, so that the service life of the carbon fibers is prolonged, and the service life of the carbon fibers is prolonged. The ablation resistance of the composite material in a high-temperature aerobic environment is obviously improved.

Description

Technical Field

[0001] This invention belongs to the field of ceramic matrix composite material preparation technology, and particularly relates to an ablation-resistant ultra-high temperature ceramic matrix composite material and its preparation method. Background Technology

[0002] Ceramic matrix composites are a class of composite materials that use carbon fiber as the toughening phase and carbide and boride ceramics such as silicon carbide, zirconium carbide, and hafnium carbide as the matrix. They possess advantages such as lightweight, high temperature resistance, high strength, and high modulus, attracting widespread attention from scientists and engineers. However, carbon fiber and carbide / boride composites have poor oxidation resistance. Carbon fiber begins to oxidize at around 400℃ in air, resulting in a significant performance degradation; while the initial oxidation temperature of ultra-high temperature ceramics such as carbides is generally below 1000℃. Once zirconium carbide, hafnium carbide, etc., oxidize to form zirconium oxide, hafnium oxide, etc., their originally dense structure begins to loosen, allowing oxygen to penetrate rapidly, ultimately leading to a rapid failure of the material's overall performance. To address these issues, researchers can introduce protective coatings such as zirconium carbide and hafnium carbide. These coatings can be prepared using techniques like chemical vapor deposition and plasma spraying. However, due to technological limitations and inherent characteristics, the initial oxidation temperature of zirconium carbide or hafnium carbide is relatively low, and the coatings cannot achieve high density; uniformity also needs further improvement. Therefore, if carbon fibers and the material matrix are not effectively protected, it will significantly impact the overall performance of the composite material, including its oxidation resistance and ablation resistance. Thus, how to further improve the oxidation resistance of ceramic matrix composites and ensure their ablation resistance in extreme aerobic environments has become a key focus in this technological field.

[0003] In summary, it is essential to provide an ablation-resistant ultra-high temperature ceramic matrix composite material and its preparation method. Summary of the Invention

[0004] To address the issue of generally poor ablation resistance in existing ultra-high temperature ceramic matrix composites and improve their ablation resistance under extreme aerobic environments, this invention provides an ablation-resistant ultra-high temperature ceramic matrix composite and its preparation method. The method employs a combination of chemical vapor deposition and atomic layer deposition (ALD) with ultra-rapid annealing to form a zirconium carbide-zirconia composite coating on the surface of the ceramic matrix composite matrix. The zirconium oxide ceramic coating has high density, effectively protecting the matrix, and introduces a pyrolytic carbon-silicon carbide composite interface layer, thereby effectively protecting the carbon fibers and preventing damage to the fibers from the ceramic matrix. This method significantly improves the material's oxidation resistance and enhances the ablation resistance of the composite under high-temperature aerobic environments, overcoming the problem of generally poor ablation resistance in ceramic matrix composites prepared using traditional techniques.

[0005] The present invention provides a method for preparing an ablation-resistant ultra-high temperature ceramic matrix composite material in a first aspect, the method comprising the following steps: (1) A porous carbon / carbon composite matrix is ​​obtained by depositing a pyrolytic carbon interface layer on the carbon fiber surface of the carbon fiber preform by chemical vapor deposition. (2) Using liquid polycarbosilane as reactant, a silicon carbide interface layer is prepared on the surface of the pyrolytic carbon interface layer of the porous carbon / carbon composite matrix by chemical vapor deposition, so as to obtain a composite matrix containing a pyrolytic carbon-silicon carbide composite interface layer. (3) Using zirconium carbide-silicon carbide composite ceramic precursor as reactant, react with the composite matrix containing the pyrolytic carbon-silicon carbide composite interface layer by impregnation pyrolysis method to obtain ceramic matrix composite matrix; (4) A zirconium carbide coating was prepared on the surface of the ceramic matrix composite substrate by chemical vapor deposition; (5) Using tetra(dimethylamino)zirconia and water as reactants, a zirconium oxide coating was prepared on the zirconium carbide coating surface of the ceramic matrix composite material matrix by atomic layer deposition and subjected to ultra-fast annealing treatment to obtain an ablation-resistant ultra-high temperature ceramic matrix composite material.

[0006] Preferably, the density of the carbon fiber preform is 0.2~0.4 g / cm³. 3 ; and / or the density of the porous carbon / carbon composite matrix is ​​0.3~0.5 g / cm³. 3 .

[0007] Preferably, the thickness of the silicon carbide interface layer is 20~200nm; and / or the thickness of the pyrolytic carbon-silicon carbide composite interface layer is 0.5~2μm.

[0008] Preferably, the thickness of the zirconium carbide coating is 0.1~5μm; and / or the thickness of the zirconium oxide coating is 50~200nm.

[0009] Preferably, in step (5): the precursors used in the atomic layer deposition process are tetra(dimethylamino)zirconium and ultrapure water, the temperature of the atomic layer deposition reaction is 220~300℃, the number of deposition cycles is 100~4000 times, and the single deposition cycle process is as follows: the pulse time of the tetra(dimethylamino)zirconium is 0.3~0.6s, and the argon purging time is 1~3s; the pulse time of the ultrapure water is 0.1~0.3s, and the argon purging time is 1~3s.

[0010] Preferably, in step (5): the ultra-fast annealing process is to heat to 650~850℃ at a heating rate of 25~50℃ / s and hold for 40~100s.

[0011] Preferably, after holding at 650~850℃ for 40~100s, the temperature is reduced to room temperature at a rate of 5~15℃ / s.

[0012] Preferably, in step (2): during chemical vapor deposition, the temperature of the liquid polycarbonylsilane is heated to 80~120℃; and / or the temperature of chemical vapor deposition is 1000~1300℃, the time is 1~2h, and the pressure in the deposition reactor is 0.1~50Pa.

[0013] Preferably, the ablation-resistant ultra-high temperature ceramic matrix composite material comprises a zirconium carbide-zirconia composite coating; and / or the ablation-resistant ultra-high temperature ceramic matrix composite material exhibits a linear ablation rate of less than or equal to 1×10⁻⁶ after ablation at 2000℃ under oxyacetylene conditions for 100 s. -3 mm / s.

[0014] In a second aspect, the present invention provides an ablation-resistant ultra-high temperature ceramic matrix composite material prepared by the preparation method described in the first aspect of the present invention.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects: (1) Silicon carbide is often prepared by conventional chemical vapor deposition using trichloromethylsilane as raw material, but the carbon-silicon ratio is often greater than 1, forming a carbon-rich silicon carbide ceramic phase; however, this invention uses liquid polycarbosilane as raw material and introduces a silicon carbide ceramic interface layer on the surface of pyrolytic carbon by chemical vapor deposition, with a carbon-silicon ratio closer to 1 and better anti-oxidation effect.

[0016] (2) This invention uses atomic layer deposition (ALD) technology to prepare a thin and smooth zirconium oxide coating on the surface of a zirconium carbide coating, forming a zirconium carbide-zirconia composite coating. Simultaneously, ultra-fast annealing is introduced to enhance the bonding force between the zirconium carbide and zirconium oxide coatings, improving the overall oxidation resistance of the material and significantly enhancing the ablation resistance of ultra-high temperature ceramic matrix composites in high-temperature aerobic environments. In existing technologies, the surface protection of zirconium-based ceramic matrix composites often employs chemical vapor deposition (CVD) to prepare zirconium carbide (ZrC) coatings to improve their oxidation and ablation resistance. However, single-layer zirconium carbide coatings oxidize in ultra-high temperature aerobic environments, accompanied by volume expansion and phase structure changes. This easily leads to stress concentration within the coating, resulting in microcracks, pore expansion, and coating peeling, making it difficult to maintain structural integrity and excellent high-temperature ablation resistance under extreme service conditions. Although zirconia theoretically possesses high thermal stability and chemical inertness, its coefficient of linear expansion differs significantly from that of zirconium carbide and silicon carbide substrates. Under high-temperature conditions, thermal stress tends to concentrate at the interface, and uniformity and density are difficult to guarantee, making it challenging to form a reliable and stable protective layer. Therefore, existing technologies lack reports on the direct preparation of single-layer zirconia coatings or the construction of zirconium carbide-zirconia composite coatings. This invention utilizes atomic layer deposition combined with ultra-fast annealing technology to construct a uniform and dense zirconia coating on the surface of a zirconium carbide coating, achieving a high match with the underlying zirconium carbide layer. This forms a zirconium carbide-zirconia composite coating structure. In this structure, the outer zirconium oxide layer provides oxidation resistance under extreme high-temperature conditions, while the inner zirconium carbide layer provides a high melting point, high thermal conductivity, and good thermal stress buffering capacity. The two layers form a gradient thermally stable transition structure, enabling the coating to maintain superior oxidation resistance, ablation resistance, and high-temperature mechanical properties. Meanwhile, the zirconium carbide-zirconia composite coating and the internal pyrolytic carbon-silicon carbide composite interface layer are matched in terms of thermal expansion coefficient and structure, forming an overall protection system of "internal interface stability - external layer anti-oxidation" from the interface to the surface, which significantly improves the high-temperature service performance and high-temperature ablation resistance of the material. Attached Figure Description

[0017] Figure 1 This is a surface morphology image of the ablation-resistant ultra-high temperature ceramic matrix composite material prepared in Example 1 of this invention after being ablated at 2000℃ for 100s with oxyacetylene. Figure 1 As can be seen, the material prepared in Example 1, through the overall protection system, exhibits excellent high-temperature ablation resistance. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0019] The present invention provides a method for preparing an ablation-resistant ultra-high temperature ceramic matrix composite material in a first aspect, the method comprising the following steps: (1) A pyrolytic carbon interface layer is deposited on the carbon fiber surface of the carbon fiber preform by chemical vapor deposition to obtain a porous carbon / carbon composite matrix (also referred to as a porous carbon / carbon matrix); those skilled in the art can prepare the porous carbon / carbon composite matrix by conventional chemical vapor deposition; the carbon fiber preform can adopt any structure such as needle punching, puncture or stitching; (2) Using liquid polycarbosilane as reactant, a silicon carbide interface layer is prepared on the surface of the pyrolytic carbon interface layer of the porous carbon / carbon composite matrix by chemical vapor deposition to form a pyrolytic carbon-silicon carbide composite interface layer, thereby obtaining a composite matrix containing the pyrolytic carbon-silicon carbide composite interface layer. (3) Using a zirconium carbide-silicon carbide composite ceramic precursor as a reactant, the ceramic matrix is ​​obtained by reacting the composite matrix containing the pyrolytic carbon-silicon carbide composite interface layer with the precursor by an impregnation pyrolysis method (precursor impregnation pyrolysis method); this step (3) is a well-known technique in the art, and those skilled in the art can prepare the ceramic matrix by using the precursor impregnation pyrolysis technique, wherein the solid content of the zirconium carbide-silicon carbide composite ceramic precursor is, for example, 25-40%, and the viscosity is, for example, 40-90 mPa·s, and by multiple impregnation, curing and pyrolysis treatments; in this invention, the zirconium carbide-silicon carbide composite ceramic precursor is, for example, oxygen-free zirconium carbide. The ceramic precursor is obtained by compounding it with polycarbosilane. Preferably, the molar ratio of zirconium contained in the oxygen-free zirconium carbide ceramic precursor to silicon contained in the polycarbosilane is 1:(0.8~1.2). Specifically, for example, the liquid oxygen-free zirconium carbide ceramic precursor and the liquid polycarbosilane are stirred at a speed of 100~400 rpm for 1~5 hours to mix them evenly to obtain the zirconium carbide-silicon carbide composite ceramic precursor. In this invention, the zirconium carbide-silicon carbide composite ceramic precursor is used as a reactant. The zirconium carbide-silicon carbide composite ceramic precursor is filled into the pores by vacuum and pressure impregnation. After curing and pyrolysis process, a ceramic matrix composite material matrix is ​​formed. (4) A zirconium carbide coating is prepared on the surface of the ceramic matrix composite material matrix by chemical vapor deposition. In this invention, step (4) is a well-known technology in the field. Those skilled in the art can use chemical vapor deposition technology to evacuate the chemical vapor deposition reaction chamber, then heat zirconium tetrachloride, using zirconium tetrachloride, propane and hydrogen as the reaction source, argon as the carrier gas, and simultaneously introduce propane and hydrogen into the chamber. The parameters such as temperature, holding time, zirconium tetrachloride, propane and hydrogen flow rate in the deposition reaction chamber are conventionally adjusted to prepare a zirconium carbide coating on the surface of the ceramic matrix composite material matrix. (5) Using tetrakis(dimethylamino)zirconia and water as reactants, a zirconia coating is prepared on the surface of the zirconia coating of the ceramic matrix composite material matrix by atomic layer deposition and then subjected to ultra-fast annealing to obtain an ablation-resistant ultra-high temperature ceramic matrix composite material. In this invention, a dense zirconia coating is prepared on the surface of the zirconia coating by atomic layer deposition, and ultra-fast annealing is performed to promote zirconia crystallization and improve the bonding force between the zirconia coating and the zirconia coating, forming a zirconia-zirconia composite coating. In this invention, the ultra-fast annealing is performed in an inert atmosphere or vacuum environment.

[0020] Silicon carbide is often prepared using trichloromethylsilane as a raw material through conventional chemical vapor deposition (CVD), but the carbon-to-silicon ratio is often greater than 1, resulting in a carbon-rich silicon carbide ceramic phase. This invention, however, uses liquid polycarbosilane as a raw material and introduces a silicon carbide ceramic interface layer onto the surface of pyrolytic carbon through CVD, achieving a carbon-to-silicon ratio closer to 1 and better oxidation resistance. This invention also uses atomic layer deposition (ALD) to prepare a thin and smooth zirconium oxide coating on the surface of a zirconium carbide coating, forming a zirconium carbide-zirconia composite coating. Simultaneously, ultra-fast annealing is introduced to enhance the adhesion between the zirconium carbide and zirconium oxide coatings, improving the overall oxidation resistance of the material and significantly enhancing the ablation resistance of ultra-high temperature ceramic matrix composites in high-temperature aerobic environments. In existing technologies, surface protection of zirconium-based ceramic matrix composites often employs CVD to prepare zirconium carbide (ZrC) coatings to improve their oxidation and ablation resistance. However, single-layer zirconium carbide coatings oxidize under ultra-high temperature and oxygen-containing environments, accompanied by volume expansion and phase structure changes. This easily leads to stress concentration within the coating, resulting in microcracks, pore propagation, and coating peeling. Consequently, it is difficult to maintain structural integrity and excellent high-temperature ablation resistance under extreme service conditions. Although zirconium oxide theoretically possesses high thermal stability and chemical inertness, its coefficient of linear expansion differs significantly from that of zirconium carbide and silicon carbide substrates. Under high-temperature conditions, thermal stress tends to concentrate at the interface, and uniformity and density are difficult to guarantee, making it difficult to form a reliable and stable protective layer. Therefore, there are no reports on the direct preparation of single-layer zirconium oxide coatings or the construction of zirconium carbide-zirconia composite coatings in the current technology. This invention utilizes atomic layer deposition combined with ultra-fast annealing technology to construct a uniform and dense zirconium oxide coating on the surface of a zirconium carbide coating, which is highly matched with the underlying zirconium carbide layer. This forms a zirconium carbide-zirconia composite coating structure. In this structure, the outer zirconium oxide layer provides oxidation stability under extreme high-temperature conditions, while the inner zirconium carbide layer provides a high melting point, high thermal conductivity, and good thermal stress buffering capacity. The two form a gradient thermally stable transition structure, enabling the coating to maintain superior oxidation resistance, ablation resistance, and high-temperature mechanical properties. Simultaneously, this zirconium carbide-zirconia composite coating matches the internal pyrolytic carbon-silicon carbide composite interface layer in terms of thermal expansion coefficient and structure, forming an overall protective system of "internal interface stability - outer layer oxidation resistance" from the interface to the surface. This significantly improves the material's high-temperature service performance and high-temperature ablation resistance.

[0021] According to some preferred embodiments, the density of the carbon fiber preform is 0.2~0.4 g / cm³. 3 ; and / or the density of the porous carbon / carbon composite matrix is ​​0.3~0.5 g / cm³. 3 In this invention, preferably, the density of the carbon fiber preform is 0.2~0.4 g / cm³. 3 The density of the porous carbon / carbon composite matrix is ​​0.3~0.5 g / cm³.3 If the density is too high, the internal pores will be too small, which will prevent polycarbosilane molecules from effectively entering the pores and affect the deposition effect of the silicon carbide interface layer; if the density is too low, the fiber volume content of the final composite material will be too low, and it will not achieve a good toughening effect.

[0022] According to some preferred embodiments, the thickness of the silicon carbide interface layer is 20~200 nm (e.g., 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190 or 200 nm); and / or the thickness of the pyrolytic carbon-silicon carbide composite interface layer is 0.5~2 μm (e.g., 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9 or 2 μm).

[0023] According to some preferred embodiments, the thickness of the zirconium carbide coating is 0.1~5 μm (e.g., 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5 or 5 μm); and / or the thickness of the zirconium oxide coating is 50~200 nm (e.g., 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190 or 200 nm), preferably 150~200 nm (e.g., 150, 160, 170, 180, 190 or 200 nm).

[0024] In this invention, preferably, the thickness of the zirconium carbide coating is controlled to be 0.1~5μm and the thickness of the zirconium oxide coating is 50~200nm, thereby achieving an optimized combination of the thicknesses of the zirconium carbide coating and the zirconium oxide coating, which significantly improves the ablation resistance of the material in a high-temperature and oxygen-containing environment. This invention finds that the zirconium carbide coating serves as the main load-bearing and high-temperature protective layer, while the thin and uniform zirconium oxide coating forms a dense oxidation barrier, inhibiting oxidation and interfacial diffusion, thereby improving the oxidation resistance and interfacial stability of the material under extreme high temperatures. Meanwhile, the matching thickness of the zirconia coating and the zirconia carbide coating effectively alleviates the interfacial stress concentration caused by the difference in thermal expansion, reduces the generation and propagation of microcracks, and thus comprehensively improves the high-temperature strength and high-temperature ablation resistance of the composite material, achieving excellent ablation resistance and reliability of the material under ultra-high temperature conditions. If the zirconia coating is too thin, its dense oxide barrier effect is insufficient, and oxygen can easily penetrate into the zirconia carbide layer at high temperatures, causing oxidation and interfacial diffusion, which can easily lead to the generation of microcracks. If the zirconia coating is too thick, due to the large difference in its thermal expansion coefficient with that of zirconia carbide, the interfacial stress concentration at high temperatures can easily lead to microcracks or peeling.

[0025] According to some preferred embodiments, in step (5): the precursors used in the atomic layer deposition process are tetrakis(dimethylamino)zirconium and ultrapure water, the temperature of the atomic layer deposition reaction is 220~300℃; the number of deposition cycles is 100~4000 times (e.g. 100, 500, 1000, 1500, 2000, 2500, 3000, 3500 or 4000 times); a single deposition cycle is as follows: the pulse time of the tetrakis(dimethylamino)zirconium is 0.3~0.6s, and the argon purging time is 1~3s; the pulse time of the ultrapure water is 0.1~0.3s, and the argon purging time is 1~3s.

[0026] According to some preferred embodiments, in step (5): the ultra-fast annealing process is to heat the temperature to 650-850°C (e.g., 650°C, 700°C, 750°C, 800°C, or 850°C) at a heating rate of 25-50°C / s (e.g., 25°C / s, 30°C / s, 35°C / s, 40°C / s, 45°C / s, or 50°C / s) for 10-60s (e.g., 10, 15, 20, 35, 30, 35, 40, 45, 50, 55, or 60s) and hold it for 40-100s (e.g., 40, 50, 60, 70, 80, 90, or 100s).

[0027] The key to step (5) of this invention lies in using atomic layer deposition (ALD) to prepare a dense zirconia coating on the surface of the zirconia coating, and simultaneously performing a suitable ultra-fast annealing process to promote the crystallization of the zirconia coating and enhance the bonding force between the zirconia coating and the zirconia coating, thereby fully leveraging the protective effect on the substrate. Although existing technologies involve rapid high-temperature sintering when preparing ceramic matrix composites, due to differences in material systems and coating structures, the parameters of existing technologies are not applicable to the zirconia coating system obtained by ALD in this invention, nor can they provide guidance for the selection of ultra-fast annealing parameters in this invention. This invention discovers that, during the formation of a zirconium carbide-zirconia composite coating, appropriate heating rates, annealing temperatures, and holding times can enhance the bonding strength between the zirconium oxide and zirconium carbide coatings while preventing the zirconium oxide coating from cracking and failing. When the heating rate is below 25°C / s, the temperature is above 850°C, or the holding time is above 100s, the zirconium oxide coating will crack and fail to provide good protection. When the heating rate is above 50°C / s, the temperature is below 650°C, or the holding time is below 40s, the bonding strength between the zirconium oxide and zirconium carbide coatings will be weak, and the zirconium oxide will have a low degree of crystallinity, leading to rapid peeling and failure under an oxidizing atmosphere. Oxygen will quickly penetrate into the matrix, causing the carbon fibers to oxidize and degrade in performance.

[0028] According to some preferred embodiments, after holding at 650~850℃ for 40~100s, the temperature is reduced to room temperature at a rate of 5~15℃ / s; in this invention, room temperature refers to room temperature of 15~35℃; in step (5) of this invention, it is preferred to control the cooling rate within the range of 5~15℃ / s. This cooling rate can achieve an optimized balance between material thermal expansion matching, interfacial bonding force and zirconium oxide crystal structure stability. Through this reasonably selected cooling rate, thermal stress concentration can be effectively alleviated, interfacial cracking can be prevented, and the density and continuity of the zirconium oxide coating can be maintained, thereby enhancing the bonding force between the zirconium oxide coating and the zirconium carbide coating. Compared with the prior art, the cooling rate and annealing parameter combination of this invention are optimized for the atomic layer deposition zirconium oxide coating system, which not only ensures the stability of the coating structure, but also fully utilizes the role of the zirconium carbide-zirconia composite coating in protecting the composite material and improving the high-temperature service reliability of the composite material, thereby obtaining a composite coating structure with high bonding force and excellent oxidation resistance that is difficult to achieve with the prior art.

[0029] According to some specific implementation methods, step (5) includes the following sub-steps: S1. The ceramic matrix composite material matrix is ​​placed in the atomic layer deposition reaction chamber (atomic layer deposition equipment cavity), and the temperature of the atomic layer deposition reaction chamber is set to 220~300℃; S2. Heat tetra(dimethylamino)zirconium at a temperature of 60~90℃; S3. Tetra(dimethylamino)zirconia is introduced into the atomic layer deposition reaction chamber in a pulsed manner and chemically adsorbed on the surface of the zirconium carbide coating of the ceramic matrix composite matrix. Excess tetra(dimethylamino)zirconia is purged out of the atomic layer deposition reaction chamber with argon gas. In step S3, the pulse time of the tetra(dimethylamino)zirconia is 0.3~0.6s, and the argon purging time is 1~3s. S4. Ultrapure water is introduced into the atomic layer deposition reaction chamber in a pulsed manner and reacts with tetra(dimethylamino)zirconia, which is chemically adsorbed on the surface of the zirconium carbide coating on the ceramic matrix composite substrate in step S3, to form a deposition reaction. Excess ultrapure water and byproducts generated after the deposition reaction are purged out of the atomic layer deposition reaction chamber with argon gas. In step S4, the pulse time of the ultrapure water is 0.1~0.3s, and the argon gas purging time is 1~3s. S5. Repeat steps S3 and S4 100 to 4000 times in sequence; wherein, steps S3 and S4 constitute one deposition cycle, and repeat steps S3 and S4 100 to 4000 times in sequence, that is, the number of deposition cycles is 100 to 4000. S6. After step S5, the temperature of the atomic layer deposition reaction chamber is reduced to below 60°C. The material is removed from the atomic layer deposition reaction chamber and placed in an argon atmosphere. The heating rate is 25-50°C / s, for example, heating to 650-850°C in 10-60s and holding for 40-100s for ultra-fast annealing to promote the crystallization of the zirconia coating and improve the bonding force between the zirconia coating and the zirconia carbide coating. After holding at 650-850°C for 40-100s, the temperature is reduced to room temperature at a cooling rate of 5-15°C / s to complete the preparation of the ablation-resistant ultra-high temperature ceramic matrix composite material.

[0030] According to some preferred embodiments, in step (2): during chemical vapor deposition, the temperature of the liquid polycarbosilane is heated to 80~120℃; in this invention, the heating temperature of the liquid polycarbosilane is preferably 80~120℃. Liquid polycarbosilane is a low viscosity, high ceramic yield liquid polymer. Its volatilization rate is low at room temperature. Heating can increase its volatilization rate. When the heating temperature is too high, cross-linking and solidification may occur inside, making it difficult for the molecules to diffuse into the internal pores, affecting the deposition effect; when the heating temperature is too low, its volatilization rate is low, which may lead to uneven thickness of the silicon carbide interface layer, failing to provide good protection for the carbon fibers; this invention does not specifically limit the liquid polycarbosilane, and conventional liquid polycarbosilane can be used; and / or the temperature of chemical vapor deposition is 1000~1300℃, the time is 1~2h, and the pressure in the deposition reactor is 0.1~50Pa.

[0031] According to some specific implementation methods, step (2) is as follows: The porous carbon / carbon composite matrix is ​​placed in a chemical vapor deposition furnace, a vacuum is drawn, the pressure inside the furnace is 0.1-50 Pa, and the temperature inside the furnace is controlled at 1000-1300℃ and held for 5-20 min to ensure that the furnace body reaches a uniform temperature state. The heating temperature of liquid polycarbosilane is controlled at 80-120℃, and nitrogen is used as a carrier gas to carry it into the chemical vapor deposition furnace cavity. Next, while maintaining nitrogen to continuously carry liquid polycarbosilane into the cavity, hydrogen is also introduced into the chemical vapor deposition furnace cavity (furnace cavity), and the flow ratio of nitrogen to hydrogen is 10:1~5, where the nitrogen flow rate is controlled at 0.1-1.0 L / min. After the furnace is held for 1-2 h, a silicon carbide interface layer is formed on the surface of the pyrolytic carbon. The sample was then cooled down, and heating of the polycarbonylsilane and hydrogen gas were stopped sequentially. Nitrogen gas was continuously introduced throughout the cooling process until the sample reached room temperature, at which point it was removed.

[0032] According to some preferred embodiments, the ablation-resistant ultra-high temperature ceramic matrix composite material comprises a zirconium carbide-zirconia composite coating; and / or the ablation-resistant ultra-high temperature ceramic matrix composite material exhibits a linear ablation rate of less than or equal to 1×10⁻⁶ after ablation at 2000°C under oxyacetylene conditions for 100 s. -3 mm / s.

[0033] In a second aspect, this invention provides an ablation-resistant ultra-high temperature ceramic matrix composite material prepared by the preparation method described in the first aspect. The ultra-high temperature ceramic matrix composite material prepared by this invention exhibits the advantage of ablation resistance, demonstrating a significant improvement in ablation resistance under high-temperature aerobic environments.

[0034] The present invention will be further described below by way of examples, but the scope of protection of the present invention is not limited to these embodiments. The present invention may have many other embodiments, and those skilled in the art can make various corresponding changes and modifications based on the present invention without departing from its spirit and essence. However, all such corresponding changes and modifications should fall within the scope of protection of the appended claims. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods. Unless otherwise specified, the materials, reagents, etc., used in the following embodiments can be obtained commercially or synthesized by existing methods.

[0035] The preparation of the oxygen-free zirconium carbide ceramic precursor involved in this invention is as follows: The three-necked flask was evacuated multiple times and filled with argon to replace the air. Tetra(dimethylamino)zirconium was added, followed by diallylamine. The mixture was stirred and reacted at 65°C in an argon atmosphere for 16 hours. Afterward, the reactants were distilled under reduced pressure to remove low-boiling-point substances, yielding a liquid oxygen-free zirconium carbide ceramic precursor. The molar ratio of tetra(dimethylamino)zirconium to diallylamine was 1:1.

[0036] The zirconium carbide-silicon carbide composite ceramic precursors involved in the following embodiments and comparative examples of the present invention are prepared as follows: liquid oxygen-free zirconium carbide ceramic precursors and liquid polycarbosilane are stirred at 150 rpm for 4 hours to mix evenly, thereby obtaining the zirconium carbide-silicon carbide composite ceramic precursors; wherein, the amounts of the oxygen-free zirconium carbide ceramic precursors and polycarbosilane are such that the molar ratio of zirconium contained in the oxygen-free zirconium carbide ceramic precursors to silicon contained in the polycarbosilane is 1:1.

[0037] Example 1 (1) Provide a porous carbon / carbon composite matrix: the density of the carbon fiber preform is 0.3 g / cm³. 3 A pyrolytic carbon interface layer with a density of 0.4 g / cm³ was prepared by depositing a pyrolytic carbon interface layer on the carbon fiber surface of a carbon fiber preform using chemical vapor deposition. 3 Porous carbon / carbon composite matrix.

[0038] (2) Preparation of pyrolytic carbon-silicon carbide composite interface layer: The porous carbon / carbon composite matrix was placed in a chemical vapor deposition furnace, a vacuum was drawn, the pressure inside the furnace was 10 Pa, and the temperature inside the furnace was controlled at 1050℃ and held for 10 min to ensure that the furnace body reached a uniform temperature state. The heating temperature of liquid polycarbosilane was controlled at 100℃, and nitrogen was used as a carrier gas to carry it into the chemical vapor deposition furnace cavity. Next, while nitrogen was continuously carrying liquid polycarbosilane into the cavity, hydrogen was also introduced into the chemical vapor deposition furnace cavity (furnace cavity), and the flow ratio of nitrogen to hydrogen was 10:3, with the nitrogen flow rate controlled at 0.6 L / min. After the furnace was held for 2 h, a silicon carbide interface layer was formed on the surface of the pyrolytic carbon. The sample was then allowed to cool naturally, and heating of the polycarbosilane and the introduction of hydrogen gas were stopped sequentially. Nitrogen gas was continuously introduced throughout the cooling process until the sample reached room temperature. The sample was then removed, yielding a composite matrix containing a pyrolytic carbon-silicon carbide composite interface layer. The silicon carbide interface layer had a thickness of 120 nm, and the pyrolytic carbon-silicon carbide composite interface layer had a thickness of 0.7 μm.

[0039] (3) Preparation of ceramic matrix composite material matrix: Using zirconium carbide-silicon carbide composite ceramic precursor as reactant, the composite material matrix containing pyrolytic carbon-silicon carbide composite interface layer is reacted with the composite material matrix by impregnation pyrolysis method (impregnation / curing / pyrolysis PIP process) to obtain ceramic matrix composite material matrix; wherein, a total of 10 rounds of impregnation, curing and pyrolysis treatment are carried out. Each impregnation is first vacuum impregnated for 1 hour at a pressure of 150 Pa, and then pressure impregnated for 1 hour at a pressure of 1.5 MPa. Each curing is carried out in an argon atmosphere at 200°C for 2 hours. Each pyrolysis temperature is 1500°C and the pyrolysis time is 2 hours. Each pyrolysis is carried out in an argon atmosphere.

[0040] (4) Preparation of zirconium carbide coating: A zirconium carbide coating with a thickness of 2 μm was prepared on the surface of the ceramic matrix composite substrate by chemical vapor deposition. The chemical vapor deposition was carried out under a pressure of 20 Pa, with zirconium tetrachloride, propane and hydrogen as the reaction source and argon as the carrier gas. The flow ratio of zirconium tetrachloride, propane, hydrogen and argon was 1:6:6:15, and the temperature of chemical vapor deposition was 1200 °C.

[0041] (5) Preparation of zirconia coating: S1. The ceramic matrix composite material substrate is placed in an atomic layer deposition (ALD) chamber, and the temperature of the ALD chamber is set to 230°C; S2. Tetra(dimethylamino)zirconia is heated to 70°C; S3. Tetra(dimethylamino)zirconia is introduced into the ALD chamber in a pulsed manner and chemically adsorbed onto the surface of the zirconia coating on the ceramic matrix composite material substrate. Excess tetra(dimethylamino)zirconia is purged out of the ALD chamber with argon gas; In step S3, the tetra(dimethylamino)zirconia... The pulse duration of zirconium carbide (ZrC) coating in step S3 is 0.4 s, and the argon purging time is 2 s; S4, ultrapure water is introduced into the atomic layer deposition (ALD) reaction chamber in a pulsed manner and reacts with the tetra(dimethylamino)zirconia chemically adsorbed on the surface of the zirconium carbide coating on the ceramic matrix composite substrate in step S3. Excess ultrapure water and byproducts generated after the deposition reaction are purged out of the ALD reaction chamber using argon gas; in step S4, the pulse duration of the ultrapure water is 0.1 s, and the argon purging time is 2 s; S5, steps S3 and S4 are repeated sequentially. 2000 times; S6. After step S5, the temperature of the atomic layer deposition reaction chamber is reduced to below 60°C, the material is taken out from the atomic layer deposition reaction chamber, and the material is placed in an argon atmosphere. The temperature is increased to 750°C at a rate of 40°C / s and held for 50s for ultra-fast annealing. Then, the temperature is reduced to room temperature at a rate of 10°C / s to obtain an ablation-resistant ultra-high temperature ceramic matrix composite material; wherein, the thickness of the zirconium oxide coating is 100nm.

[0042] Oxyacetylene ablation resistance test at 2000℃: The ablation-resistant ultra-high temperature ceramic matrix composite material prepared in this example was tested at 2000℃ in an oxyacetylene environment for 100 s, and its linear ablation rate was 0.41 × 10⁻⁶. -3 mm / s.

[0043] Example 2 Example 2 is basically the same as Example 1, except that: In step S6, after step S5, the temperature of the atomic layer deposition reaction chamber is reduced to below 60°C, the material is removed from the atomic layer deposition reaction chamber, and the material is placed in an argon atmosphere. The temperature is increased to 650°C at a rate of 40°C / s and held for 50s for ultra-fast annealing. Then, the temperature is reduced to room temperature at a rate of 10°C / s to obtain an ablation-resistant ultra-high temperature ceramic matrix composite material. The thickness of the zirconium oxide coating is 100nm.

[0044] Oxyacetylene ablation resistance test at 2000℃: The ablation-resistant ultra-high temperature ceramic matrix composite material prepared in this example was tested and found to have a linear ablation rate of 0.52 × 10⁻⁶ after 100 s of ablation in an oxyacetylene environment at 2000℃. -3 mm / s.

[0045] Example 3 Example 3 is basically the same as Example 1, except that: In step S6, after step S5, the temperature of the atomic layer deposition reaction chamber is reduced to below 60°C, the material is removed from the atomic layer deposition reaction chamber, and the material is placed in an argon atmosphere. The temperature is increased to 850°C at a rate of 40°C / s and held for 50s for ultra-fast annealing. Then, the temperature is reduced to room temperature at a rate of 10°C / s to obtain an ablation-resistant ultra-high temperature ceramic matrix composite material. The thickness of the zirconium oxide coating is 100nm.

[0046] Oxyacetylene ablation resistance test at 2000℃: The ablation-resistant ultra-high temperature ceramic matrix composite material prepared in this example was tested and found to have a linear ablation rate of 0.36 × 10⁻⁶ after 100 s of ablation in an oxyacetylene environment at 2000℃. -3 mm / s.

[0047] Example 4 Example 4 is basically the same as Example 1, except that: In step S6, after step S5, the temperature of the atomic layer deposition reaction chamber is reduced to below 60°C, the material is removed from the atomic layer deposition reaction chamber, and the material is placed in an argon atmosphere. The temperature is increased to 750°C at a rate of 40°C / s and held for 80s for ultra-fast annealing. Then, the temperature is reduced to room temperature at a rate of 10°C / s to obtain an ablation-resistant ultra-high temperature ceramic matrix composite material. The thickness of the zirconium oxide coating is 100nm.

[0048] Oxyacetylene ablation resistance test at 2000℃: The ablation-resistant ultra-high temperature ceramic matrix composite material prepared in this example was tested and found to have a linear ablation rate of 0.33 × 10⁻⁶ after 100 s of ablation in an oxyacetylene environment at 2000℃. -3 mm / s.

[0049] Example 5 Example 5 is basically the same as Example 1, except that: In step S6, after step S5, the temperature of the atomic layer deposition reaction chamber is reduced to below 60°C, the material is removed from the atomic layer deposition reaction chamber, and the material is placed in an argon atmosphere. The temperature is increased to 1000°C at a rate of 40°C / s and held for 80s for ultra-fast annealing. Then, the temperature is reduced to room temperature at a rate of 10°C / s to obtain an ablation-resistant ultra-high temperature ceramic matrix composite material. The thickness of the zirconium oxide coating is 100nm.

[0050] Oxyacetylene ablation resistance test at 2000℃: The ablation-resistant ultra-high temperature ceramic matrix composite material prepared in this example was tested in an oxyacetylene environment at 2000℃ for 100 s, and its linear ablation rate was 1.49 × 10⁻⁶. -3 mm / s.

[0051] As can be seen from Examples 1-5 above, compared to Example 1, in Example 2, the processing temperature was reduced from 750℃ to 650℃ during the ultra-rapid annealing process. This resulted in a decrease in the crystallinity of zirconia and the bonding strength between the zirconia coating and the zirconia carbide coating, leading to a decrease in the protective effect of the ceramic composite coating and a reduction in the linear ablation rate from 0.41×10⁻⁶. -3 mm / s increased to 0.52 × 10 -3 mm / s. Compared to Example 1, in Example 3, the processing temperature was increased from 750℃ to 850℃ during ultra-fast annealing, which improved the crystallinity of zirconia and the bonding strength between the zirconia coating and the zirconia carbide coating, thus enhancing the protective effect of the ceramic composite coating and reducing the linear ablation rate from 0.41×10 mm / s. -3 mm / s decreased to 0.36 × 10 -3 mm / s. In Example 4, during ultra-fast annealing, the holding time was extended from 50s to 80s, which improved the crystallinity of zirconia and the bonding strength between the zirconia and zirconia carbide coatings, thus enhancing the protective effect of the ceramic composite coating and reducing the linear ablation rate from 0.41×10 mm / s. -3 mm / s decreased to 0.33 × 10 -3 mm / s. In Example 5, during ultra-fast annealing, the processing temperature was increased from 750℃ to 1000℃, which significantly improved the crystallinity of zirconia. However, the bonding strength between the zirconia coating and the zirconia carbide coating decreased significantly, and the zirconia coating exhibited cracking. This reduced the protective effect of the ceramic composite coating, leading to a decrease in the linear ablation rate from 0.41 × 10⁻⁶ mm / s. -3 mm / s increased to 1.49 × 10 -3 mm / s.

[0052] Examples 6-12 The specific process parameters of Examples 6-12 and the performance indicators of the final ultra-high temperature ceramic matrix composite materials are shown in Table 1. Other preparation processes are the same as in Example 1.

[0053] Table 1 As shown in Table 1 above, compared to Example 1, in Example 6, the processing temperature was reduced from 750℃ to 500℃ during ultra-rapid annealing. This resulted in lower zirconia crystallinity and lower bonding strength between the zirconia and zirconium carbide coatings, leading to a decrease in the protective effect of the ceramic composite coating and a reduction in the linear ablation rate from 0.41×10⁻⁶. -3 mm / s increased to 0.95×10-3 mm / s. In Example 7, during ultra-rapid annealing, the heating rate decreased from 40℃ / s to 10℃ / s, causing cracking in the zirconia coating and a decrease in the protective effect of the ceramic composite coating, resulting in a decrease in the linear ablation rate from 0.41×10 mm / s. -3 mm / s increased to 1.28 × 10 -3 mm / s. In Example 8, during ultra-fast annealing, the heating rate was increased from 40℃ / s to 100℃ / s. The bonding strength between the zirconium oxide coating and the zirconium carbide coating was low, resulting in rapid detachment during the ablation process, causing the linear ablation rate to decrease from 0.41×10 mm / s. -3 mm / s increased to 1.83 × 10 - 3 mm / s. In Example 9, during ultra-fast annealing, the holding time was extended from 50s to 180s, resulting in cracking of the zirconia coating and a decrease in the protective effect of the ceramic composite coating, leading to a decrease in the linear ablation rate from 0.41×10 mm / s. -3 mm / s increased to 1.15 × 10 -3 mm / s. In Example 10, the coating thickness was increased from 100 nm to 150 nm during the preparation of the zirconia coating, further enhancing its ablation resistance. The protective effect of the ceramic composite coating was improved, resulting in an increase in the linear ablation rate from 0.41 × 10⁻⁶ mm / s. -3 mm / s decreased to 0.22 × 10 -3 mm / s. In Example 11, when the zirconia coating was prepared, the coating thickness was reduced from 100 nm to 30 nm, which significantly affected the ablation resistance, resulting in a decrease in the linear ablation rate from 0.41 × 10⁻⁶ mm / s. -3 mm / s increased to 2.16 × 10 -3 mm / s. In Example 12, during the preparation of the silicon carbide interface layer, the heating temperature of the liquid polycarbosilane was increased from 100°C to 150°C, causing cross-linking of the polycarbosilane. This prevented the polymer molecules from being introduced into the reaction chamber by nitrogen gas, thus hindering the effective acquisition of the silicon carbide interface layer and resulting in a decrease in the linear ablation rate from 0.41 × 10⁻⁶ mm / s. - 3 mm / s increased to 1.67 × 10 -3 mm / s.

[0054] Example 13 Example 13 is basically the same as Example 1, except that: In step S6, after holding the ultra-fast annealing treatment at 750℃ for 50 seconds, the temperature is reduced to room temperature at a cooling rate of 5℃ / min.

[0055] Oxyacetylene ablation resistance test at 2000℃: The ultra-high temperature ceramic matrix composite material prepared in this example was tested to have a linear ablation rate of 2.31 × 10⁻⁶ after 100 s of ablation in an oxyacetylene environment at 2000℃. -3mm / s.

[0056] Example 14 Example 14 is basically the same as Example 1, except that: In step S6, after holding the ultra-fast annealing treatment at 750℃ for 50 seconds, the temperature is reduced to room temperature at a cooling rate of 20℃ / s.

[0057] Oxyacetylene ablation resistance test at 2000℃: The ultra-high temperature ceramic matrix composite material prepared in this example was tested and found to have a linear ablation rate of 0.91 × 10⁻⁶ after 100 s of ablation in an oxyacetylene environment at 2000℃. -3 mm / s.

[0058] Example 15 Example 15 is basically the same as Example 1, except that: In step S6, after holding the ultra-fast annealing treatment at 750℃ for 50s, the temperature is reduced to room temperature at a cooling rate of 50℃ / s.

[0059] Oxyacetylene ablation resistance test at 2000℃: The ultra-high temperature ceramic matrix composite material prepared in this example was tested and found to have a linear ablation rate of 1.07 × 10⁻⁶ after 100 s of ablation in an oxyacetylene environment at 2000℃. -3 mm / s.

[0060] Example 16 Example 16 is basically the same as Example 1, except that: In step S6, after step S5, the temperature of the atomic layer deposition reaction chamber is reduced to below 60°C, the material is removed from the atomic layer deposition reaction chamber, and the material is placed in an argon atmosphere. The temperature is increased to 1500°C at a rate of 40°C / s and held for 50s for ultra-fast annealing. Then, the temperature is reduced to room temperature at a rate of 10°C / s to obtain an ablation-resistant ultra-high temperature ceramic matrix composite material. The thickness of the zirconium oxide coating is 100nm.

[0061] Oxyacetylene ablation resistance test at 2000℃: The ultra-high temperature ceramic matrix composite material prepared in this example was tested and found to have a linear ablation rate of 3.62 × 10⁻¹⁰ after 100 s of ablation in an oxyacetylene environment at 2000℃. -3 mm / s.

[0062] Comparative Example 1 Comparative Example 1 is basically the same as Example 1, except that: (2) Preparation of pyrolytic carbon-silicon carbide composite interface layer: The porous carbon / carbon composite matrix was placed in a chemical vapor deposition furnace, a vacuum was drawn, the pressure inside the furnace was 10 Pa, and the temperature inside the furnace was controlled at 1050℃ and held for 10 min to ensure that the furnace body reached a uniform temperature state. A silicon carbide source gas containing trichloromethylsilane, argon and hydrogen was introduced to deposit a silicon carbide interface layer, thus obtaining a composite matrix containing a pyrolytic carbon-silicon carbide composite interface layer; wherein, the thickness of the silicon carbide interface layer was 120 nm, and the thickness of the pyrolytic carbon-silicon carbide composite interface layer was 0.7 μm.

[0063] Oxyacetylene ablation resistance test at 2000℃: The ultra-high temperature ceramic matrix composite material prepared in this comparative example was tested and found to have a linear ablation rate of 0.74 × 10⁻⁶ after 100 s of ablation in an oxyacetylene environment at 2000℃. -3 mm / s.

[0064] Comparative Example 2 Comparative Example 2 is basically the same as Example 1, except that: (5) Preparation of zirconia coating: S1. The ceramic matrix composite material substrate is placed in an atomic layer deposition (ALD) chamber, and the temperature of the ALD chamber is set to 230°C; S2. Tetra(dimethylamino)zirconia is heated to 70°C; S3. Tetra(dimethylamino)zirconia is introduced into the ALD chamber in a pulsed manner and chemically adsorbed onto the surface of the zirconia coating on the ceramic matrix composite material substrate. Excess tetra(dimethylamino)zirconia is purged out of the ALD chamber with argon gas; In step S3, the tetra(dimethylamino)zirconia... The pulse duration of zirconium oxide is 0.4 s, and the argon purging time is 2 s; S4, ultrapure water is introduced into the atomic layer deposition reaction chamber in a pulse manner and reacts with tetra(dimethylamino)zirconia, which is chemically adsorbed on the surface of the zirconium carbide coating of the ceramic matrix composite matrix in step S3, to form a deposition reaction. Excess ultrapure water and byproducts generated after the deposition reaction are purged out of the atomic layer deposition reaction chamber with argon gas; in step S4, the pulse duration of the ultrapure water is 0.1 s, and the argon purging time is 2 s; S5, steps S3 and S4 are repeated 2000 times; S6, after step S5, the temperature of the atomic layer deposition reaction chamber is reduced to below 60°C, and the material is taken out of the atomic layer deposition reaction chamber to obtain an ablation-resistant ultra-high temperature ceramic matrix composite material; wherein, the thickness of the zirconium oxide coating is 100 nm.

[0065] Oxyacetylene ablation resistance test at 2000℃: The ultra-high temperature ceramic matrix composite material prepared in this comparative example was tested and found to have a linear ablation rate of 4.12 × 10⁻¹⁰ after 100 s of ablation in an oxyacetylene environment at 2000℃. -3 mm / s.

[0066] Comparative Example 3 Comparative Example 3 is basically the same as Example 1, except that: Step (5) is excluded; that is, after preparing a zirconium carbide coating with a thickness of 2 μm on the surface of the ceramic matrix composite material matrix by chemical vapor deposition, an ultra-high temperature ceramic matrix composite material is obtained.

[0067] Oxyacetylene ablation resistance test at 2000℃: The ultra-high temperature ceramic matrix composite material prepared in this comparative example was tested and found to have a linear ablation rate of 5.24 × 10⁻¹⁰ after 100 s of ablation in an oxyacetylene environment at 2000℃. -3 mm / s.

[0068] Comparative Example 4 (1) Same as step (1) in Example 1.

[0069] (2) Preparation of ceramic matrix composite material matrix: Using zirconium carbide-silicon carbide composite ceramic precursor as reactant, the porous carbon / carbon composite material matrix is ​​reacted with the precursor by impregnation pyrolysis method (impregnation / curing / pyrolysis PIP process) to obtain ceramic matrix composite material matrix; wherein, a total of 10 rounds of impregnation, curing and pyrolysis treatment are carried out. Each impregnation is first vacuum impregnated for 1 hour at a pressure of 150 Pa, and then pressure impregnated for 1 hour at a pressure of 1.5 MPa. Each curing is carried out in an argon atmosphere at 200°C for 2 hours. Each pyrolysis temperature is 1500°C and the pyrolysis time is 2 hours. Each pyrolysis is carried out in an argon atmosphere.

[0070] (3) Preparation of zirconium carbide coating: A zirconium carbide coating with a thickness of 2 μm was prepared on the surface of the ceramic matrix composite substrate by chemical vapor deposition; wherein, chemical vapor deposition was carried out under a pressure of 20 Pa, using zirconium tetrachloride, propane and hydrogen as reaction sources, and argon as carrier gas to carry zirconium tetrachloride into the chemical vapor deposition reaction chamber. The flow ratio of zirconium tetrachloride, propane, hydrogen and argon was 1:6:6:15, and the temperature of chemical vapor deposition was 1200℃. (4) Preparation of zirconia coating: S1. The ceramic matrix composite material substrate is placed in an atomic layer deposition (ALD) chamber, and the temperature of the ALD chamber is set to 230°C; S2. Tetra(dimethylamino)zirconia is heated to 70°C; S3. Tetra(dimethylamino)zirconia is introduced into the ALD chamber in a pulsed manner and chemically adsorbed on the surface of the zirconia coating of the ceramic matrix composite material substrate. Excess tetra(dimethylamino)zirconia is purged out of the ALD chamber with argon gas; In step S3, the tetra(dimethylamino)zirconia... The pulse duration of zirconium carbide (ZrC) coating in step S3 is 0.4 s, and the argon purging time is 2 s; S4, ultrapure water is introduced into the atomic layer deposition (ALD) reaction chamber in a pulsed manner and reacts with the tetra(dimethylamino)zirconia chemically adsorbed on the surface of the zirconium carbide coating on the ceramic matrix composite substrate in step S3. Excess ultrapure water and byproducts generated after the deposition reaction are purged out of the ALD reaction chamber using argon gas; in step S4, the pulse duration of the ultrapure water is 0.1 s, and the argon purging time is 2 s; S5, steps S3 and S4 are repeated sequentially. 2000 times; S6. After step S5, the temperature of the atomic layer deposition reaction chamber is reduced to below 60°C, the material is taken out from the atomic layer deposition reaction chamber, and the material is placed in an argon atmosphere. The temperature is increased to 750°C at a rate of 40°C / s and held for 50s for ultra-fast annealing. Then, the temperature is reduced to room temperature at a rate of 10°C / s to obtain an ultra-high temperature ceramic matrix composite material; wherein, the thickness of the zirconium oxide coating is 100nm.

[0071] Oxyacetylene ablation resistance test at 2000℃: The ultra-high temperature ceramic matrix composite material prepared in this comparative example was tested and found to have a linear ablation rate of 1.72 × 10⁻⁶ after 100 s of ablation in an oxyacetylene environment at 2000℃. -3 mm / s.

[0072] The parts of this invention not described in detail are techniques known to those skilled in the art.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing an ablation-resistant ultra-high temperature ceramic matrix composite material, characterized in that, The method includes the following steps: (1) A porous carbon / carbon composite matrix is ​​obtained by depositing a pyrolytic carbon interface layer on the carbon fiber surface of the carbon fiber preform by chemical vapor deposition. (2) Using liquid polycarbosilane as reactant, a silicon carbide interface layer is prepared on the surface of the pyrolytic carbon interface layer of the porous carbon / carbon composite matrix by chemical vapor deposition, so as to obtain a composite matrix containing a pyrolytic carbon-silicon carbide composite interface layer. (3) Using zirconium carbide-silicon carbide composite ceramic precursor as reactant, react with the composite matrix containing the pyrolytic carbon-silicon carbide composite interface layer by impregnation pyrolysis method to obtain ceramic matrix composite matrix; (4) A zirconium carbide coating was prepared on the surface of the ceramic matrix composite substrate by chemical vapor deposition; (5) Using tetra(dimethylamino)zirconia and water as reactants, a zirconium oxide coating was prepared on the zirconium carbide coating surface of the ceramic matrix composite material matrix by atomic layer deposition and subjected to ultra-fast annealing treatment to obtain an ablation-resistant ultra-high temperature ceramic matrix composite material.

2. The preparation method according to claim 1, characterized in that: The density of the carbon fiber preform is 0.2~0.4 g / cm³. 3 ; and / or The density of the porous carbon / carbon composite matrix is ​​0.3~0.5 g / cm³. 3 .

3. The preparation method according to claim 1, characterized in that: The thickness of the silicon carbide interface layer is 20~200nm; and / or The thickness of the pyrolytic carbon-silicon carbide composite interface layer is 0.5~2μm.

4. The preparation method according to claim 1, characterized in that: The zirconium carbide coating has a thickness of 0.1~5μm; and / or The thickness of the zirconium oxide coating is 50~200nm.

5. The preparation method according to any one of claims 1 to 4, characterized in that, In step (5): The precursors used in the atomic layer deposition process are tetra(dimethylamino)zirconium and ultrapure water, and the temperature of the atomic layer deposition reaction is 220~300℃. The deposition cycle number is 100~4000 times; The single deposition cycle process is as follows: the pulse time of the tetra(dimethylamino)zirconia is 0.3~0.6s, and the argon purging time is 1~3s; the pulse time of the ultrapure water is 0.1~0.3s, and the argon purging time is 1~3s.

6. The preparation method according to any one of claims 1 to 4, characterized in that, In step (5): The ultra-rapid annealing process involves heating to 650-850℃ at a heating rate of 25-50℃ / s and holding at that temperature for 40-100s.

7. The preparation method according to claim 6, characterized in that: After holding at 650~850℃ for 40~100s, cool down to room temperature at a rate of 5~15℃ / s.

8. The preparation method according to any one of claims 1 to 4, characterized in that, In step (2): During chemical vapor deposition, the liquid polycarbosilane is heated to 80-120°C; and / or The temperature for chemical vapor deposition is 1000~1300℃, the time is 1~2h, and the pressure inside the deposition reactor is 0.1~50Pa.

9. The preparation method according to any one of claims 1 to 4, characterized in that: The ablation-resistant ultra-high temperature ceramic matrix composite material includes a zirconium carbide-zirconia composite coating; and / or The ablation-resistant ultra-high temperature ceramic matrix composite material exhibits a linear ablation rate of less than or equal to 1×10⁻⁶ under oxyacetylene conditions at 2000℃ for 100 s. -3 mm / s.

10. An ablation-resistant ultra-high temperature ceramic matrix composite material prepared by any one of claims 1 to 9.

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