An ultra-high-temperature-resistant wear-resistant ceramic matrix composite material and a preparation method thereof

Abstract

The application discloses a kind of ultra-high temperature resistant wear-resistant ceramic matrix composite material and preparation method thereof, belong to ceramic material technical field.The composite material includes the following raw materials: interface modified polyacrylonitrile-based carbon fiber, allyl modified polycarbosilane, polysilazane, silicon carbide, boron carbide, titanium carbide, titanium carbonitride, cobalt, molybdenum, phenolic resin and silane coupling agent;Preparation method specifically includes the following steps: (1) weighing raw materials;(2) the preparation of ceramic precursor;(3) liquid phase impregnation forming and low-temperature curing;(4) high-temperature thermalization and densification treatment;(5) finished product is completed.The application takes carbon fiber as reinforcing framework, takes silicon carbide ceramic as matrix, improves the denseness, high-temperature stability, hardness, fracture toughness and wear resistance of composite material by the design of ceramic matrix of multi-component synergistic strengthening and advanced liquid phase preparation process, so as to significantly improve the comprehensive service performance thereof in extreme environment, and can be used for aero-engine hot end component.

Description

Technical Field

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

[0002] As the aerospace industry continues to demand higher performance from thermal structural materials, traditional metallic materials are struggling to meet the requirements under extreme conditions such as high temperatures and intense wear. While single ceramic materials possess high-temperature stability and hardness, their high brittleness and poor thermal shock resistance limit their application in complex structural components.

[0003] Currently, carbon fiber reinforced silicon carbide (Cf / SiC) ceramic matrix composites have become a research hotspot in the field of thermal structural materials due to their lightweight, high strength, and high temperature resistance. However, existing Cf / SiC ceramic matrix composites still have many shortcomings in terms of preparation processes and performance: traditional chemical vapor infiltration (CVI) processes are time-consuming and costly, making it difficult to efficiently prepare large-size complex components; insufficient matrix density and weak interfacial bonding make the materials prone to interfacial debonding and matrix cracking under high-temperature friction environments, seriously affecting their service life and reliability.

[0004] Therefore, how to develop a novel Cf / SiC ceramic matrix composite material is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide an ultra-high temperature resistant and wear-resistant ceramic matrix composite material and its preparation method, so as to overcome the shortcomings of the prior art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A high-temperature resistant and wear-resistant ceramic matrix composite material comprises the following raw materials in parts by weight: 47-48.5 parts of interface-modified polyacrylonitrile (PAN) based carbon fiber, 17.5-19.5 parts of allyl-modified polycarbosilane (PCS), 7-8 parts of polysilazane (PSZ), 8.5-9.5 parts of silicon carbide (SiC), 1.3-1.7 parts of boron carbide (B4C), 5.7-6.3 parts of titanium carbide (TiC), 4.7-5.3 parts of titanium carbonitride (Ti(C,N)), 1.8-2.2 parts of cobalt (Co), 1.8-2.2 parts of molybdenum (Mo), 0.9-1.1 parts of phenolic resin, and 0.45-0.55 parts of silane coupling agent;

[0008] The surface of the aforementioned interface-modified polyacrylonitrile-based carbon fiber has a boron nitride (BN) coating with a thickness of 100-300 nm.

[0009] The preferred composition is: 47 parts of interface-modified polyacrylonitrile-based carbon fiber, 18.5 parts of allyl-modified polycarbosilane, 7.5 parts of polysilazane, 9 parts of silicon carbide, 1.5 parts of boron carbide, 6 parts of titanium carbide, 5 parts of titanium carbonitride, 2 parts of cobalt, 2 parts of molybdenum, 1 part of phenolic resin, and 0.5 parts of silane coupling agent.

[0010] The preferred composition is: 48 parts of interface-modified polyacrylonitrile-based carbon fiber, 17.8 parts of allyl-modified polycarbosilane, 7.4 parts of polysilazane, 8.7 parts of silicon carbide, 1.6 parts of boron carbide, 6 parts of titanium carbide, 5.1 parts of titanium carbonitride, 1.9 parts of cobalt, 1.9 parts of molybdenum, 1.1 parts of phenolic resin, and 0.5 parts of silane coupling agent.

[0011] The preferred composition is: 47.5 parts of interface-modified polyacrylonitrile-based carbon fiber, 18.7 parts of allyl-modified polycarbosilane, 7.3 parts of polysilazane, 8.8 parts of silicon carbide, 1.4 parts of boron carbide, 6.2 parts of titanium carbide, 4.9 parts of titanium carbonitride, 1.9 parts of cobalt, 1.9 parts of molybdenum, 0.9 parts of phenolic resin, and 0.5 parts of silane coupling agent.

[0012] In this invention, the functions of each raw material are as follows:

[0013] Interface-modified polyacrylonitrile-based carbon fibers serve as the main load-bearing skeleton, providing strength and toughness.

[0014] Allyl-modified polycarbosilane generates a SiC toughening phase, which improves creep resistance.

[0015] Polysilazane generates a Si3N4 toughening phase, which improves creep resistance.

[0016] Silicon carbide inhibits thermal shrinkage.

[0017] Boron carbide is a highly efficient sintering aid that promotes densification.

[0018] Titanium carbide is a hard phase, which improves hardness and thermal conductivity.

[0019] Titanium carbonitride is a hard phase that enhances wear resistance and erosion resistance.

[0020] Cobalt acts as a metallic binder phase, aiding in sintering and increasing toughness.

[0021] Molybdenum acts as a metallic binder phase, improving high-temperature strength.

[0022] Phenolic resin has antioxidant properties and promotes synergistic sintering.

[0023] Silane coupling agents are interfacial coupling agents that enhance interfacial bonding.

[0024] Among them, titanium carbide and titanium carbonitride in a mass ratio of (1.0-1.3):1 constitute a high-hardness and wear-resistant phase; cobalt and molybdenum in a mass ratio of (0.8-1.2):1 constitute a metallic binder phase; and phenolic resin serves as an in-situ carbon source and synergistic sintering agent.

[0025] Furthermore, the preparation method of the above-mentioned interface-modified polyacrylonitrile-based carbon fiber is as follows: first, the polyacrylonitrile-based carbon fiber is pretreated, and then placed in a chemical vapor deposition furnace. Under the conditions of 900-1000℃, 500Pa pressure and inert atmosphere, a reaction gas containing boron source (boron trichloride, BCl3) and nitrogen source (ammonia, NH3) is introduced and reacted for 2.8-3.2h. A boron nitride coating with a thickness of 100-300nm is deposited on the surface of the polyacrylonitrile-based carbon fiber, thus obtaining the product.

[0026] Furthermore, the diameter of the aforementioned interface-modified polyacrylonitrile-based carbon fibers is 5-7µm; the particle size of silicon carbide powder is 0.03-0.06µm; the particle size of boron carbide powder is 0.2-0.5µm; the particle size of titanium carbide powder is 0.8-1.5µm; the particle size of titanium carbonitride powder is 0.5-0.8µm; the particle size of cobalt powder is 0.5-2µm; and the particle size of molybdenum powder is 0.5-2µm.

[0027] Furthermore, the aforementioned silane coupling agent is γ-aminopropyltriethoxysilane.

[0028] It should be noted that this invention is not a superposition of the properties of a single raw material, but rather an integrated system constructed through multi-component synergistic design, consisting of a "reinforcing skeleton - high-hardness and wear-resistant phase - bonding and toughening phase - interface-regulating phase." The components create a synergistic effect, the specific mechanism of which is as follows:

[0029] 1. Enhance the interfacial coordination between the skeleton and the substrate.

[0030] The 100-300nm BN coating on the surface of polyacrylonitrile-based carbon fibers modified with boron nitride (BN) coating can effectively alleviate the interfacial stress between the carbon fibers and the SiC matrix, prevent the formation of brittle phases at high temperatures, and improve the interfacial bonding strength, so that the load-bearing and toughening effects of the carbon fibers can be fully exerted, thus solving the key problem of interfacial debonding in traditional Cf / SiC composite materials.

[0031] 2. Synergistic effect of high-hardness and wear-resistant phases

[0032] Titanium carbide (TiC) and titanium carbonitride (Ti(C,N)) are compounded at a mass ratio of (1.0-1.3):1 to form a complementary high-hardness phase system. The high hardness of TiC improves the wear resistance of the material matrix, while the grain boundary strengthening effect of Ti(C,N) inhibits grain growth. The two work together to optimize the microstructure of the matrix, making the wear resistance and erosion resistance of the material significantly better than that of a single hard phase system under high-temperature friction environment.

[0033] 3. Synergistic toughening of the metal binder phase

[0034] Cobalt (Co) and molybdenum (Mo) are combined in a mass ratio of (0.8-1.2):1. Co's low melting point promotes sintering densification, while Mo's high-temperature stability enhances the material's high-temperature strength. The resulting metal network structure can effectively bridge matrix cracks, alleviate stress concentration, and significantly improve the brittle defects of ceramic materials.

[0035] 4. Synergistic reaction between precursors and inorganic powders

[0036] When allyl-modified polycarbosilane (PCS) is blended with polysilazane (PSZ), it is converted into SiC and Si3N4 phases respectively during thermal curing, forming a continuous and dense ceramic matrix with the added SiC powder. Boron carbide (B4C) acts as a sintering aid, which can reduce the sintering temperature and promote grain refinement. Phenolic resin provides an in-situ carbon source, which works synergistically with the metal phase to optimize the matrix density and antioxidant properties.

[0037] A method for preparing an ultra-high temperature resistant and wear-resistant ceramic matrix composite material specifically includes the following steps:

[0038] (1) Weigh the raw materials

[0039] Weigh each raw material according to the above-mentioned proportions of ultra-high temperature resistant and wear-resistant ceramic matrix composite material;

[0040] (2) Preparation of ceramic precursors

[0041] First, allyl-modified polycarbosilane, polysilazane, titanium carbide, titanium carbonitride, cobalt, molybdenum, dispersant and mixed solvent are stirred and mixed in a reactor. Then, phenolic resin and silane coupling agent are added at a rate of 5-15 g / min and stirred and mixed. Finally, silicon carbide and boron carbide are added at a rate of 5-15 g / min. The mixture is dispersed by high-energy ultrasonic treatment and mechanical stirring for 1.5 h and then vacuum degassing for 30 min to obtain a uniform, stable and low-viscosity ceramic precursor.

[0042] (3) Liquid phase impregnation molding and low temperature curing

[0043] Interface-modified polyacrylonitrile-based carbon fibers are laid on a mold to form a fiber preform. Under a vacuum of not less than -0.09 MPa, a ceramic precursor is introduced and completely impregnated into the fiber preform to obtain a green body. Then, under vacuum or pressure protection, the green body is first heated to 80°C at a rate of 1-2°C / min and held for 60-90 min, then heated to 150°C at a rate of 2°C / min and held for 60 min, and finally heated to 220°C at a rate of 1.5°C / min and held for 120-180 min to complete low-temperature curing. After natural cooling to below 60°C, the green body is demolded to obtain a cured green body.

[0044] (4) High-temperature heat treatment and densification

[0045] The solidified preform is placed in a high-temperature furnace under an inert atmosphere and heated to 1400-1700℃ at a rate of 1-3℃ / min and held for 2-4 hours to obtain a ceramic matrix. Then, the liquid phase impregnation molding and low-temperature curing in step (3) and the high-temperature thermal curing in step (4) are repeated 3-8 times until the density is ≥95% to obtain a dense composite preform.

[0046] (5) Finished product completed

[0047] The dense composite material blank is ground with diamond tools or laser to obtain the finished product of ultra-high temperature resistant and wear-resistant ceramic matrix composite material.

[0048] Furthermore, in step (2) above, the dispersant is a solvent composed of polyacrylate and oleic acid mixed in a volume ratio of (8-9):1, and the amount used is 2 parts by weight.

[0049] Furthermore, in step (2) above, the mixed solvent is a solvent composed of xylene and isopropanol mixed in a volume ratio of (8-9):1, and the amount used is 45 parts by weight.

[0050] The further beneficial effects of using the above methods are that the dispersant stabilizes the slurry and prevents particle agglomeration, while the mixed solvent adjusts the viscosity and improves the slurry's fluidity. It should be noted that both the dispersant and the mixed solvent are process media added to facilitate the preparation process and are not included in the final composite material's weight percentage composition; they are completely removed during heat treatment.

[0051] As can be seen from the above technical solution, compared with the prior art, the beneficial effects of the present invention are as follows:

[0052] 1. This invention employs a multi-component synergistic optimized formulation design. It uses interface-modified polyacrylonitrile-based carbon fibers as the reinforcing skeleton, SiC ceramic converted from PCS / PSZ blend precursors as the matrix, and introduces TiC and Ti(C,N) as hard phases, and Co and Mo as binder phases. TiC acts as a nucleating agent in the matrix, promoting grain refinement, while Ti(C,N) is mainly distributed at grain boundaries, effectively preventing grain growth and increasing grain boundary density. Co and Mo, as binder phases, further enhance the matrix density. Through this design, the final material maintains excellent high-temperature performance while significantly improving hardness, wear resistance, and fracture toughness compared to traditional Cf / SiC ceramic matrix composites.

[0053] 2. This invention employs a liquid-phase impregnation-thermal curing process, first manufacturing complex components through liquid molding, and then converting them in situ into ceramics. This effectively solves the bottleneck problems of traditional CVI processes, such as long cycle times, high costs, and difficulty in molding large-sized complex parts, demonstrating significant advantages for engineering applications. The low-temperature curing step effectively fixes the shape of the preform, while the subsequent high-temperature thermal curing and PIP densification cycle ensure the high purity and high density of the final material. The resulting high-temperature resistant, ultra-hard, and tough Cf / SiC ceramic matrix composite material exhibits high hardness, high toughness, and low wear, not only improving the material's service life but also well meeting the stringent requirements of high-end fields such as aerospace for thermal structural components.

[0054] 3. This invention uses carbon fiber as a reinforcing skeleton and silicon carbide ceramic as a matrix. Through multi-component synergistic strengthening ceramic matrix design and advanced liquid phase preparation process, the density, high temperature stability, hardness, fracture toughness and wear resistance of the composite material are improved, thereby significantly enhancing its comprehensive service performance in extreme environments. It can be used for hot-end components of aero engines. Attached Figure Description

[0055] Figure 1 This is a flowchart illustrating the preparation process of the ultra-high temperature resistant and wear-resistant ceramic matrix composite material of the present invention. Detailed Implementation

[0056] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0057] In the following examples, the diameter of the interface-modified polyacrylonitrile-based carbon fiber is 5-7µm; the particle size of silicon carbide powder is 0.03-0.06µm; the particle size of boron carbide powder is 0.2-0.5µm; the particle size of titanium carbide powder is 0.8-1.5µm; the particle size of titanium carbonitride powder is 0.5-0.8µm; the particle size of cobalt powder is 0.5-2µm; and the particle size of molybdenum powder is 0.5-2µm.

[0058] Example 1

[0059] The ultra-high temperature resistant and wear-resistant ceramic matrix composite material comprises the following raw materials by weight: 47g of interface-modified polyacrylonitrile-based carbon fiber, 18.5g of allyl-modified polycarbosilane, 7.5g of polysilazane, 9g of silicon carbide, 1.5g of boron carbide, 6g of titanium carbide, 5g of titanium carbonitride, 2g of cobalt, 2g of molybdenum, 1g of phenolic resin, and 0.5g of γ-aminopropyltriethoxysilane;

[0060] The preparation method of interface-modified polyacrylonitrile-based carbon fiber is as follows: First, polyacrylonitrile-based carbon fiber (T800 carbon fiber cloth) is ultrasonically cleaned with acetone for 15 min and dried in an oven at 70℃ for 1 h. Then, it is placed in a chemical vapor deposition furnace, and under the conditions of 950℃, 500Pa pressure and inert atmosphere, boron trichloride and ammonia are introduced as reaction gases. The reaction is carried out for 3 h, and a boron nitride coating with a thickness of 150 nm is deposited on the surface of polyacrylonitrile-based carbon fiber. After cooling in the furnace, it is taken out to obtain the product.

[0061] The preparation method of the above-mentioned ultra-high temperature resistant and wear-resistant ceramic matrix composite material, such as Figure 1 As shown, the specific steps include:

[0062] (1) Weigh the raw materials

[0063] Weigh each raw material according to the weight of the above-mentioned ultra-high temperature resistant and wear-resistant ceramic matrix composite material;

[0064] (2) Preparation of ceramic precursors

[0065] First, allyl-modified polycarbosilane, polysilazane, titanium carbide, titanium carbonitride, cobalt, molybdenum, dispersant and mixed solvent were stirred and mixed in a reactor. Then, phenolic resin and γ-aminopropyltriethoxysilane were added at a rate of 10 g / min and stirred and mixed. Finally, silicon carbide and boron carbide were added at a rate of 10 g / min. The mixture was dispersed by high-energy ultrasonic treatment and mechanical stirring for 1.5 h and then vacuum degassing for 30 min to obtain a uniform, stable and low-viscosity ceramic precursor.

[0066] The dispersant is a solvent composed of polyacrylate and oleic acid in a volume ratio of 9:1, with a dosage of 2g; the mixed solvent is a solvent composed of xylene and isopropanol in a volume ratio of 9:1, with a dosage of 45g.

[0067] (3) Liquid phase impregnation molding and low temperature curing

[0068] Interface-modified polyacrylonitrile-based carbon fibers were laid on a mold in a quasi-isotropic symmetrical layup pattern [0 / 45 / -45 / 90]s to construct a fiber preform. Using vacuum-assisted resin transfer molding (VARTM) technology, a ceramic precursor was introduced and completely impregnated into the fiber preform under a vacuum of not less than -0.09 MPa to obtain a green body. Then, under vacuum or pressure protection, the green body was first heated to 80℃ at a rate of 1.5℃ / min and held for 80 min, then heated to 150℃ at a rate of 2℃ / min and held for 60 min, and finally heated to 220℃ at a rate of 1.5℃ / min and held for 180 min to complete low-temperature curing. After natural cooling to below 60℃, the green body was demolded to obtain a cured green body.

[0069] (4) High-temperature heat treatment and densification

[0070] The solidified preform was placed in a high-temperature furnace under an inert atmosphere and heated to 1600℃ at a rate of 2℃ / min and held for 3h to obtain a ceramic matrix. Then, the liquid phase impregnation molding and low-temperature curing in step (3) and the high-temperature thermal curing in step (4) were repeated. After 6 cycles, the density was ≥95% to obtain a dense composite preform.

[0071] (5) Finished product completed

[0072] The dense composite material blank is cut and surface-ground using a diamond grinding wheel to obtain a finished product of ultra-high temperature resistant and wear-resistant ceramic matrix composite material with precise dimensions.

[0073] Example 2

[0074] The ultra-high temperature resistant and wear-resistant ceramic matrix composite material comprises the following raw materials by weight: 48g of interface-modified polyacrylonitrile-based carbon fiber, 17.8g of allyl-modified polycarbosilane, 7.4g of polysilazane, 8.7g of silicon carbide, 1.6g of boron carbide, 6g of titanium carbide, 5.1g of titanium carbonitride, 1.9g of cobalt, 1.9g of molybdenum, 1.1g of phenolic resin, and 0.5g of γ-aminopropyltriethoxysilane;

[0075] The preparation method of interface-modified polyacrylonitrile-based carbon fiber is as follows: First, polyacrylonitrile-based carbon fiber (T800 carbon fiber cloth) is ultrasonically cleaned with acetone for 15 min and dried in an oven at 70℃ for 1 h. Then, it is placed in a chemical vapor deposition furnace, and under a temperature of 1000℃, a pressure of 500Pa and an inert atmosphere, boron trichloride and ammonia are introduced as reaction gases. The reaction is carried out for 3.2 h, and a boron nitride coating with a thickness of 150 nm is deposited on the surface of polyacrylonitrile-based carbon fiber. After cooling in the furnace, it is taken out to obtain the product.

[0076] The preparation method of the above-mentioned ultra-high temperature resistant and wear-resistant ceramic matrix composite material, such as Figure 1 As shown, the specific steps include:

[0077] (1) Weigh the raw materials

[0078] Weigh each raw material according to the weight of the above-mentioned ultra-high temperature resistant and wear-resistant ceramic matrix composite material;

[0079] (2) Preparation of ceramic precursors

[0080] First, allyl-modified polycarbosilane, polysilazane, titanium carbide, titanium carbonitride, cobalt, molybdenum, dispersant and mixed solvent were stirred and mixed in a reactor. Then, phenolic resin and γ-aminopropyltriethoxysilane were added at a rate of 8 g / min and stirred and mixed. Finally, silicon carbide and boron carbide were added at a rate of 8 g / min. The mixture was dispersed by high-energy ultrasonic treatment and mechanical stirring for 1.5 h and then vacuum degassing for 30 min to obtain a uniform, stable and low-viscosity ceramic precursor.

[0081] The dispersant is a solvent composed of polyacrylate and oleic acid in a volume ratio of 9:1, with a dosage of 2g; the mixed solvent is a solvent composed of xylene and isopropanol in a volume ratio of 9:1, with a dosage of 45g.

[0082] (3) Liquid phase impregnation molding and low temperature curing

[0083] Interface-modified polyacrylonitrile-based carbon fibers were laid on a mold in a quasi-isotropic symmetrical layup pattern [0 / 45 / -45 / 90]s to form a fiber preform. Using vacuum-assisted resin transfer molding (VARTM) technology, a ceramic precursor was introduced and completely impregnated into the fiber preform under a vacuum of not less than -0.09 MPa to obtain a green body. Then, under vacuum or pressure protection, the green body was first heated to 80℃ at a rate of 1.5℃ / min and held for 90 min, then heated to 150℃ at a rate of 2℃ / min and held for 60 min, and finally heated to 220℃ at a rate of 1.5℃ / min and held for 180 min to complete low-temperature curing. After natural cooling to below 60℃, the green body was demolded to obtain a cured green body.

[0084] (4) High-temperature heat treatment and densification

[0085] The solidified preform was placed in a high-temperature furnace under an inert atmosphere and heated to 1550℃ at a rate of 1.5℃ / min and held for 3 hours to obtain a ceramic matrix. Then, the liquid phase impregnation molding and low-temperature curing in step (3) and the high-temperature thermal curing in step (4) were repeated. After 7 cycles, the density was ≥95%, and a dense composite preform was obtained.

[0086] (5) Finished product completed

[0087] The dense composite material blank is cut and surface-ground using a diamond grinding wheel to obtain a finished product of ultra-high temperature resistant and wear-resistant ceramic matrix composite material with precise dimensions.

[0088] Example 3

[0089] The ultra-high temperature resistant and wear-resistant ceramic matrix composite material comprises the following raw materials by weight: 47.5g of interface-modified polyacrylonitrile-based carbon fiber, 18.7g of allyl-modified polycarbosilane, 7.3g of polysilazane, 8.8g of silicon carbide, 1.4g of boron carbide, 6.2g of titanium carbide, 4.9g of titanium carbonitride, 1.9g of cobalt, 1.9g of molybdenum, 0.9g of phenolic resin, and 0.5g of γ-aminopropyltriethoxysilane;

[0090] The preparation method of interface-modified polyacrylonitrile-based carbon fiber is as follows: First, polyacrylonitrile-based carbon fiber (T800 carbon fiber cloth) is ultrasonically cleaned with acetone for 15 min and dried in an oven at 70℃ for 1 h. Then, it is placed in a chemical vapor deposition furnace, and under a temperature of 900℃, a pressure of 500Pa and an inert atmosphere, boron trichloride and ammonia are introduced as reaction gases. The reaction is carried out for 2.8 h, and a boron nitride coating with a thickness of 150 nm is deposited on the surface of polyacrylonitrile-based carbon fiber. After cooling in the furnace, it is taken out to obtain the product.

[0091] The preparation method of the above-mentioned ultra-high temperature resistant and wear-resistant ceramic matrix composite material, such as Figure 1 As shown, the specific steps include:

[0092] (1) Weigh the raw materials

[0093] Weigh each raw material according to the weight of the above-mentioned ultra-high temperature resistant and wear-resistant ceramic matrix composite material;

[0094] (2) Preparation of ceramic precursors

[0095] First, allyl-modified polycarbosilane, polysilazane, titanium carbide, titanium carbonitride, cobalt, molybdenum, dispersant and mixed solvent were stirred and mixed in a reactor. Then, phenolic resin and γ-aminopropyltriethoxysilane were added at a rate of 12 g / min and stirred and mixed. Finally, silicon carbide and boron carbide were added at a rate of 12 g / min. The mixture was dispersed by high-energy ultrasonic treatment and mechanical stirring for 1.5 h and then vacuum degassing for 30 min to obtain a uniform, stable and low-viscosity ceramic precursor.

[0096] The dispersant is a solvent composed of polyacrylate and oleic acid in a volume ratio of 9:1, with a dosage of 2g; the mixed solvent is a solvent composed of xylene and isopropanol in a volume ratio of 9:1, with a dosage of 45g.

[0097] (3) Liquid phase impregnation molding and low temperature curing

[0098] Interface-modified polyacrylonitrile-based carbon fibers were laid on a mold in a quasi-isotropic symmetrical layup pattern [0 / 45 / -45 / 90]s to form a fiber preform. Using vacuum-assisted resin transfer molding (VARTM) technology, a ceramic precursor was introduced and completely impregnated into the fiber preform under a vacuum of not less than -0.09 MPa to obtain a green body. Then, under vacuum or pressure protection, the green body was first heated to 80℃ at a rate of 1.8℃ / min and held for 70 min, then heated to 150℃ at a rate of 2℃ / min and held for 60 min, and finally heated to 220℃ at a rate of 1.5℃ / min and held for 170 min to complete low-temperature curing. After natural cooling to below 60℃, the green body was demolded to obtain a cured green body.

[0099] (4) High-temperature heat treatment and densification

[0100] The solidified preform was placed in a high-temperature furnace under an inert atmosphere and heated to 1650℃ at a rate of 2.5℃ / min and held for 3 hours to obtain a ceramic matrix. Then, the liquid phase impregnation molding and low-temperature curing in step (3) and the high-temperature thermal curing in step (4) were repeated. After 8 cycles, the density was ≥95%, and a dense composite preform was obtained.

[0101] (5) Finished product completed

[0102] The dense composite material blank is cut and surface-ground using a diamond grinding wheel to obtain a finished product of ultra-high temperature resistant and wear-resistant ceramic matrix composite material with precise dimensions.

[0103] Performance testing

[0104] I. Screening Tests for Raw Materials and Process Parameters

[0105] To determine the optimal raw material ratio and process conditions, this invention conducted a systematic screening experiment based on Example 2. The key screening process is as follows:

[0106] 1. Raw material ratio screening test

[0107] (1) Screening of carbon fiber interface modification schemes

[0108] Using the thickness of the BN coating on the carbon fiber surface as a variable (50nm, 100nm, 200nm, 300nm, 400nm), the interfacial bonding strength and oxidation resistance were compared through tensile tests and high-temperature oxidation tests. The results are shown in Table 1.

[0109] Table 1. Effect of BN coating thickness

[0110]

[0111] As shown in Table 1, when the coating thickness is 100-300 nm, the interfacial shear strength is ≥35 MPa, and the mass loss rate after oxidation at 1600℃ for 5 h is ≤1.2%. The interfacial bonding strength and anti-oxidation performance reach the optimal balance, and the overall performance is optimal. Therefore, this thickness range is determined to be the best modification parameter.

[0112] (2) Screening of high hardness phase ratio

[0113] With other raw material amounts fixed, the mass ratio of TiC to Ti(C,N) was adjusted (0.8:1, 1.0:1, 1.2:1, 1.4:1), and Vickers hardness and abrasion resistance tests were conducted. The results are shown in Table 2.

[0114] Table 2 Effect of TiC and Ti(C,N) mass ratio

[0115]

[0116] Table 2 shows that when the mass ratio of TiC to Ti(C,N) is (1.0-1.2):1, the material hardness is ≥2840 HV and the high-temperature volumetric wear rate is ≤5.9×10⁻⁶. -6 mm³ / (N With a grain boundary density ≥93.5%, the material hardness and wear resistance first increase and then decrease with the increase of TiC ratio. The comprehensive performance reaches the optimal value at 1.2:1, with the hard phase synergistic effect being the most significant, and the material hardness and wear resistance being the best.

[0117] (3) Screening of metal binder ratio

[0118] Fracture toughness and high-temperature strength tests were conducted using the mass ratio of Co to Mo (0.6:1, 0.8:1, 1.0:1, 1.2:1, 1.4:1) as variables, and the results are shown in Table 3.

[0119] Table 3 Effect of Co to Mo mass ratio

[0120]

[0121] As shown in Table 3, when the mass ratio of Co to Mo is (0.8-1.2):1, the fracture toughness of the material is ≥21.3 MPa. The material has a flexural strength of ≥532MPa at 1400℃. With the increase of Co content, the fracture toughness and high temperature flexural strength of the material show a trend of first increasing and then decreasing. The comprehensive mechanical properties reach the peak at 1.0:1. The toughening and strengthening effect of the binder phase is the best, and the comprehensive mechanical properties of the material are the best.

[0122] (4) Screening of adjuvant dosage

[0123] Multiple dosage gradient experiments were conducted on silane coupling agent (γ-aminopropyltriethoxysilane) and phenolic resin. The results are shown in Table 4.

[0124] Table 4. Effect of Silane Coupling Agent and Phenolic Resin Dosage

[0125]

[0126] As shown in Table 4, the interfacial bonding efficiency is optimal when the silane coupling agent content is 0.45-0.55 parts; when the phenolic resin content is 0.9-1.1 parts, it can provide sufficient carbon source while avoiding excessive carbon residue that would lead to a decline in matrix performance.

[0127] (5) Powder particle size screening

[0128] The effects of powders with different particle sizes, such as SiC (0.02μm, 0.03-0.06μm, 0.1μm), TiC (0.5μm, 0.8-1.5μm, 2.0μm), and Ti(C,N) (0.5-0.8μm, 1.0μm), on the material properties were compared, and the results are shown in Table 5.

[0129] Table 5. Effect of SiC, TiC, and Ti(C,N) particle size

[0130]

[0131] Note: The wettability rating is "Grade A" for complete wettability with no aggregation, "Grade B" for basic wettability with a small amount of aggregation, and "Grade C" for partial wettability with significant aggregation.

[0132] As shown in Table 5, when the particle size of SiC is 0.03-0.06 μm, the particle size of TiC is 0.8-1.5 μm, and the particle size of Ti(C,N) is 0.5-0.8 μm, the powder bulk density and precursor wettability are optimal, which can significantly improve the matrix density.

[0133] 2. Process parameter screening test

[0134] (1) Screening of ceramic precursor preparation processes

[0135] The results of comparing different dispersion methods (mechanical stirring, ultrasonic dispersion, and ultrasonic-mechanical stirring synergy) and dispersion times (0.5h, 1h, 1.5h) are shown in Table 6.

[0136] Table 6. Influence of Dispersion Mode

[0137]

[0138] As shown in Table 6, by using high-energy ultrasound and mechanical stirring to disperse the slurry for 1.5 hours, combined with vacuum degassing for 30 minutes, the particle size uniformity of the precursor slurry can be ≤4.2μm, the stability can reach 48 hours, and the matrix defect rate is only 2.1%. At this time, the agglomeration of solid particles can be effectively avoided, the slurry stability and uniformity are optimal, and the matrix defect rate is the lowest.

[0139] (2) Screening of low-temperature curing processes

[0140] Differential scanning calorimetry (DSC) and tensile tests were conducted with heating rate (1℃ / min, 1.5℃ / min, 2℃ / min) and curing temperature (180℃, 200℃, 220℃, 230℃) as variables. The results are shown in Table 7.

[0141] Table 7. Effects of Heating Rate Combinations

[0142]

[0143] As shown in Table 7, the segmented heating regime of 1.5→2→1.5℃ / min (holding at 80℃ for 60-90min→holding at 150℃ for 60min→holding at 220℃ for 120-180min) can achieve a green body solidification degree of ≥93.1%, a cracking rate of only 0.8%, and a subsequent pyrolysis and thermalization qualification rate of 98.5%, laying the foundation for the optimal green body for subsequent processes.

[0144] (8) High-temperature thermalization and densification cyclic screening

[0145] The effects of thermal temperature (1300℃, 1400-1700℃, 1800℃) and number of cycles (3, 6, 8) on density were investigated, and the results are shown in Table 8.

[0146] Table 8. Effect of heating temperature and number of cycles

[0147]

[0148] As shown in Table 8, when heated to 1400-1700℃ and cycled 6-8 times, the porosity of the material can be reduced to below 5%. After 6 cycles, the porosity is 3.2%, and the process cost coefficient is 1.00. The porosity and process cost reach the optimal balance. Further increasing the number of cycles (8 times) has limited effect on improving density and significantly increases the process cost (coefficient 1.35). Therefore, the optimal number of cycles is determined to be 6-8 times, and the basic number of cycles should not be less than 3 times.

[0149] Through the above systematic screening tests, the raw material ratio range and process parameters of the present invention were finally determined to ensure that the synergistic effect of each component is fully exerted, so that the composite material has ultra-high temperature stability, high hardness, high toughness and excellent wear resistance, and meets the service requirements of extreme environments such as hot end components of aero engines.

[0150] II. Performance Testing of Ceramic Matrix Composite Products

[0151] The ceramic matrix composite materials prepared in Examples 1-3 were used to verify the comprehensive service performance of the materials through systematic performance testing, with a focus on identifying and addressing insufficient toughness (fracture toughness KIC < 12 MPa). Defects such as "m¹ / ²", "insufficient hardness (Vickers hardness HV < 15GPa)", "internal macroscopic cracks", and "cracks, pores, or delamination areas with a single-direction size exceeding 500μm" are identified. Specific detection methods and results are as follows:

[0152] 1. Mechanical property testing

[0153] (1) Fracture toughness test

[0154] Standard specimens were prepared using the single-sided notched beam (SENB) method according to GB / T 4741-2016 "Test Method for Fracture Toughness of Ceramic Materials". The specimen dimensions were 2mm × 4mm × 20mm, with a notch depth of 1 / 3 of the specimen thickness and a notch width ≤ 0.2mm. Testing was conducted using an electronic universal testing machine (loading rate 0.5mm / min, span 16mm). The results showed that the fracture toughness of Examples 1-3 was 25.2 MPa, respectively. m¹ / ², 29.1 MPa m¹ / ², 21.8 MPa m¹ / ², all of which are far higher than the critical value for "insufficient toughness" (12 MPa). The m¹ / ² indicates that the material has excellent resistance to crack propagation.

[0155] (2) Vickers hardness test

[0156] According to GB / T 16534-2009 "Test Method for Room Temperature Hardness of Fine Ceramics", a Vickers hardness tester was used. The test load was 10 kgf, and the holding time was 15 s. Five different test points were selected for each sample, and the average value was taken. The test results showed that the Vickers hardness of Examples 1-3 were 2950 HV, 2780 HV, and 3420 HV, respectively, all significantly higher than the critical value of "insufficient hardness" (15 GPa, corresponding to a Vickers hardness of approximately 1450 HV), ensuring the wear resistance of the material under extreme working conditions.

[0157] 2. Microstructural integrity detection

[0158] Field emission scanning electron microscopy (FE-SEM) was used to observe the cross-section and internal microstructure of the materials, combined with X-ray diffraction (XRD) analysis of the phase composition, and non-destructive testing was performed using ultrasonic testing and industrial CT scanning. The results showed that the composite materials prepared in Examples 1-3 had no macroscopic cracks, no cracks, pores, or delamination regions with a single-direction size exceeding 500 μm; the microporosity was ≤5%, and the proportion of target phases such as SiC, Si3N4, and TiC in the phase composition was ≥95%, with no obvious impurity phases or interface debonding phenomena, meeting the requirements for microstructural integrity.

[0159] 3. High-temperature performance testing

[0160] (1) High-temperature antioxidant performance test

[0161] According to GB / T 13303-2008 "Determination of Oxidation Resistance of Steel", a static oxidation experiment was conducted at 1600℃ in an aerobic atmosphere for 5 hours. The oxidation weight loss rate was calculated by testing the change in sample mass before and after oxidation. The results showed that the oxidation weight loss rates of Examples 1-3 were 0.95%, 1.15%, and 0.78%, respectively, all ≤1.2%, indicating that the material has good structural stability in a high-temperature aerobic environment.

[0162] (2) High-temperature wear resistance test

[0163] A high-temperature friction and wear testing machine was used at 1200℃ with Si3N4 ceramic balls as the grinding pair, a loading pressure of 5N, a sliding speed of 0.3m / s, and a sliding distance of 1000m to test the high-temperature volumetric wear rate of the samples. The results showed that the high-temperature volumetric wear rates of Examples 1-3 were 4.5×10⁻⁶. -6 mm³ / (N m), 5.9×10 -6 mm³ / (N m), 2.9×10 -6 mm³ / (N m), all ≤6.0×10 -6 mm³ / (N m), demonstrating the material's excellent high-temperature wear resistance.

[0164] The results of the above experiments are shown in Table 9.

[0165] Table 9. Fracture toughness, hardness, and high-temperature resistance of ceramic matrix composite products from Examples 1-3.

[0166]

[0167] As shown in Table 9, the ceramic matrix composites prepared in Examples 1-3 exhibit excellent performance in terms of fracture toughness, hardness, high-temperature volumetric wear rate, oxidation weight loss rate, and microstructure integrity, thus avoiding various defect problems. Among them, Example 2 showed the highest fracture toughness, and Example 3 showed the highest hardness.

[0168] The above tests demonstrate that the composite material of the present invention can possess high toughness, high wear resistance, and oxidation resistance under extreme environments such as high temperature and strong wear, meeting the application requirements of high-end fields such as hot-end components of aero engines.

[0169] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A ceramic matrix composite material resistant to ultra-high temperature and wear, characterized in that, The raw materials include the following parts by weight: 47-48.5 parts of interface-modified polyacrylonitrile-based carbon fiber, 17.5-19.5 parts of allyl-modified polycarbosilane, 7-8 parts of polysilazane, 8.5-9.5 parts of silicon carbide, 1.3-1.7 parts of boron carbide, 5.7-6.3 parts of titanium carbide, 4.7-5.3 parts of titanium carbonitride, 1.8-2.2 parts of cobalt, 1.8-2.2 parts of molybdenum, 0.9-1.1 parts of phenolic resin, and 0.45-0.55 parts of silane coupling agent; The surface of the interface-modified polyacrylonitrile-based carbon fiber has a boron nitride coating with a thickness of 100-300 nm.

2. The ultra-high temperature resistant and wear-resistant ceramic matrix composite material according to claim 1, characterized in that, The raw materials include the following parts by weight: 47 parts of interface-modified polyacrylonitrile-based carbon fiber, 18.5 parts of allyl-modified polycarbosilane, 7.5 parts of polysilazane, 9 parts of silicon carbide, 1.5 parts of boron carbide, 6 parts of titanium carbide, 5 parts of titanium carbonitride, 2 parts of cobalt, 2 parts of molybdenum, 1 part of phenolic resin, and 0.5 parts of silane coupling agent.

3. The ultra-high temperature resistant and wear-resistant ceramic matrix composite material according to claim 1, characterized in that, The raw materials include the following parts by weight: 48 parts of interface-modified polyacrylonitrile-based carbon fiber, 17.8 parts of allyl-modified polycarbosilane, 7.4 parts of polysilazane, 8.7 parts of silicon carbide, 1.6 parts of boron carbide, 6 parts of titanium carbide, 5.1 parts of titanium carbonitride, 1.9 parts of cobalt, 1.9 parts of molybdenum, 1.1 parts of phenolic resin, and 0.5 parts of silane coupling agent.

4. The ultra-high temperature resistant and wear-resistant ceramic matrix composite material according to claim 1, characterized in that, The raw materials include the following parts by weight: 47.5 parts of interface-modified polyacrylonitrile-based carbon fiber, 18.7 parts of allyl-modified polycarbosilane, 7.3 parts of polysilazane, 8.8 parts of silicon carbide, 1.4 parts of boron carbide, 6.2 parts of titanium carbide, 4.9 parts of titanium carbonitride, 1.9 parts of cobalt, 1.9 parts of molybdenum, 0.9 parts of phenolic resin, and 0.5 parts of silane coupling agent.

5. The ultra-high temperature resistant and wear-resistant ceramic matrix composite material according to claim 1, characterized in that, The preparation method of the interface-modified polyacrylonitrile-based carbon fiber is as follows: first, the polyacrylonitrile-based carbon fiber is pretreated, and then placed in a chemical vapor deposition furnace. Under the conditions of 900-1000℃, 500Pa pressure and inert atmosphere, a reaction gas containing boron source and nitrogen source is introduced and reacted for 2.8-3.2h. A boron nitride coating with a thickness of 100-300nm is deposited on the surface of the polyacrylonitrile-based carbon fiber, thus obtaining the product.

6. The ultra-high temperature resistant and wear-resistant ceramic matrix composite material according to claim 1, characterized in that, The interface-modified polyacrylonitrile-based carbon fiber has a diameter of 5-7 µm; the silicon carbide powder has a particle size of 0.03-0.06 µm; the boron carbide powder has a particle size of 0.2-0.5 µm; the titanium carbide powder has a particle size of 0.8-1.5 µm; the titanium carbonitride powder has a particle size of 0.5-0.8 µm; the cobalt powder has a particle size of 0.5-2 µm; and the molybdenum powder has a particle size of 0.5-2 µm.

7. The ultra-high temperature resistant and wear-resistant ceramic matrix composite material according to claim 1, characterized in that, The silane coupling agent is γ-aminopropyltriethoxysilane.

8. A method for preparing an ultra-high temperature resistant and wear-resistant ceramic matrix composite material, characterized in that, Specifically, the following steps are included: (1) Weigh the raw materials Weigh each raw material according to the weight proportions of the ultra-high temperature resistant and wear-resistant ceramic matrix composite material according to any one of claims 1-7; (2) Preparation of ceramic precursors First, allyl-modified polycarbosilane, polysilazane, titanium carbide, titanium carbonitride, cobalt, molybdenum, dispersant and mixed solvent are stirred and mixed in a reactor. Then, phenolic resin and silane coupling agent are added at a rate of 5-15 g / min and stirred and mixed. Finally, silicon carbide and boron carbide are added at a rate of 5-15 g / min. The mixture is dispersed by high-energy ultrasonic treatment and mechanical stirring for 1.5 h and then vacuum degassing for 30 min to obtain a uniform, stable and low-viscosity ceramic precursor. (3) Liquid phase impregnation molding and low temperature curing Interface-modified polyacrylonitrile-based carbon fibers are laid on a mold to form a fiber preform. Under a vacuum of not less than -0.09 MPa, a ceramic precursor is introduced and completely impregnated into the fiber preform to obtain a green body. Then, under vacuum or pressure protection, the green body is first heated to 80°C at a rate of 1-2°C / min and held for 60-90 min, then heated to 150°C at a rate of 2°C / min and held for 60 min, and finally heated to 220°C at a rate of 1.5°C / min and held for 120-180 min to complete low-temperature curing. After natural cooling to below 60°C, the green body is demolded to obtain a cured green body. (4) High-temperature heat treatment and densification The solidified preform is placed in a high-temperature furnace under an inert atmosphere and heated to 1400-1700℃ at a rate of 1-3℃ / min and held for 2-4 hours to obtain a ceramic matrix. Then, the liquid phase impregnation molding and low-temperature curing in step (3) and the high-temperature thermal curing in step (4) are repeated 3-8 times until the density is ≥95% to obtain a dense composite preform. (5) Finished product completed The dense composite material blank is ground using diamond tools or laser to obtain the finished ultra-high temperature resistant and wear-resistant ceramic matrix composite material.

9. The method for preparing an ultra-high temperature resistant and wear-resistant ceramic matrix composite material according to claim 8, characterized in that, In step (2), the dispersant is a solvent composed of polyacrylate and oleic acid in a volume ratio of (8-9):1, and the amount used is 2 parts by weight; the mixed solvent is a solvent composed of xylene and isopropanol in a volume ratio of (8-9):1, and the amount used is 45 parts by weight.

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