A silicon carbide fiber reinforced ceramic matrix composite material, its preparation method and application

Abstract

The present invention provides a silicon carbide fiber reinforced ceramic matrix composite material, a preparation method and an application thereof, belonging to the technical field of ceramic matrix composite materials. The composite material includes a silicon carbide fiber reinforced phase, a boron nitride interface layer and a silicon-based multiphase ceramic matrix from inside to outside. The silicon-based multiphase ceramic matrix includes an infiltration reaction product phase, an introduced ceramic particle phase and a silicon-containing binary alloy phase. The infiltration reaction product phase includes a water and oxygen corrosion resistant phase, a silicon phase, a silicon carbide phase and a boride phase. The water and oxygen corrosion resistant phase includes a compound of boron and any one element of yttrium, ytterbium, hafnium, molybdenum and aluminum. The boride phase includes B 12 (C,Si,B)3. The flexural strength of the composite material is ≥600 MPa, and the fracture toughness is ≥19 MPa·m 1 / 2 . The present invention optimizes the matching between the components of the composite material, improves the mechanical properties of the composite material, and provides new ideas and process methods for preparing high-strength and water and oxygen corrosion resistant ceramic matrix composite materials.

Description

Technical Field

[0001] The present invention relates to the technical field of ceramic matrix composites, and more particularly, to a silicon carbide fiber reinforced ceramic matrix composite, its preparation method and application. Background Art

[0002] Silicon carbide fiber reinforced silicon carbide ceramic matrix (SiC f / SiC) composites not only inherit the advantages of silicon carbide ceramic materials such as high temperature resistance, wear resistance, corrosion resistance and creep resistance, but also make up for the deficiencies of ceramic materials in toughness and poor resistance to external impact loads through the reinforcement and toughening mechanism of silicon carbide fibers, and have excellent comprehensive properties. Therefore, silicon carbide fiber reinforced silicon carbide ceramic matrix (SiC f / SiC) composites are widely used in fields such as aeroengines. The working environment of aeroengines is extremely harsh, and they need to operate under various conditions such as high temperature, complex stress, water vapor corrosion and sand erosion, and at the same time, they also need to have a long service life. However, under high temperature and water vapor conditions, SiC will react with water vapor to generate volatile substances such as SiO(OH)2 and Si(OH)4, and the commonly used BN interface will also react with water vapor to generate volatile H3BO3. These reactions will cause the composite material to fail rapidly and cannot meet the requirements of its long-life use.

[0003] In order to improve the water-oxygen corrosion resistance of silicon carbide fiber reinforced silicon carbide ceramic matrix composites, the SiC matrix is often modified. In Document 1 "Li Jingxin, Liu Yongsheng, He Fang, et al. Preparation and properties of SiC / SiC-SiYC with excellent water-oxygen corrosion resistance[J]. Journal of the European Ceramic Society, 2023, 43(14): 6606-6611.", Li et al. introduced a carbon source and a silicon-yttrium (Si-Y) alloy into the SiC matrix by RMI to prepare SiC f / SiC-SiYC composites. The porosity of this material is only 2.0%. After water-oxygen corrosion, the dense oxide layer formed on the surface effectively protects the composite material, indicating that introducing Si-Y alloy into SiC f / SiC can construct a matrix with water-oxygen corrosion resistance. Chinese Patent ZL202210239625.8 uses a method of vacuum impregnation combined with reactive melt infiltration, and utilizes the reaction between Si-Y alloy and B4C to generate a Si-Y-B-C quaternary matrix to obtain SiC f / Si-Y-B-C composite materials effectively improve the water and oxygen corrosion resistance of silicon carbide fiber-reinforced silicon carbide ceramic matrix composites.

[0004] Although introducing Si-Y alloy into the SiC matrix to generate water and oxygen corrosion-resistant phases and self-healing phases under water and oxygen corrosion conditions is an effective method to improve the water and oxygen corrosion resistance of silicon carbide fiber-reinforced silicon carbide ceramic matrix composites, the existence of internal cracks in the Si-Y-C and Si-Y-B-C matrices significantly reduces the high-temperature mechanical properties of the composites, thus affecting the service life of aeroengines. Therefore, how to improve the water and oxygen corrosion resistance of silicon carbide fiber-reinforced silicon carbide ceramic matrix composites while solving the crack defects in the composites due to residual thermal stress, making them have both excellent mechanical properties and water and oxygen corrosion resistance, is an urgent problem to be solved at present. Summary of the Invention

[0005] Aiming at the deficiencies in the prior art, the present invention provides a silicon carbide fiber-reinforced ceramic matrix composite material, its preparation method and application. The silicon carbide fiber-reinforced ceramic matrix composite material has both excellent mechanical properties and water and oxygen corrosion resistance by improving the modulus matching between the components of the composite material.

[0006] The specific technical solution of the present invention is as follows:

[0007] In the first aspect, the present invention provides a silicon carbide fiber-reinforced ceramic matrix composite material, which includes a silicon carbide fiber reinforcement phase, a boron nitride interface layer, and a silicon-based multiphase ceramic matrix from the inside to the outside. The phase composition of the silicon-based multiphase ceramic matrix includes an infiltration reaction product phase, an introduced ceramic particle phase, and a silicon-containing binary alloy phase. The alloying elements in the silicon-containing binary alloy are any one of yttrium, ytterbium, hafnium, molybdenum, and aluminum. The infiltration reaction product phase includes a water and oxygen corrosion-resistant phase, a silicon phase, a silicon carbide phase, and a boride phase. The water and oxygen corrosion-resistant phase includes a compound of boron and any one of the elements yttrium, ytterbium, hafnium, molybdenum, and aluminum. The boride phase includes B 12 (C,Si,B)3. The particle size of the ceramic particles in the ceramic particle phase is 0.1 - 10 μm. The flexural strength of the silicon carbide fiber-reinforced ceramic matrix composite material is ≥600 MPa, and the fracture toughness is ≥19 MPa·m 1 / 2 .

[0008] The present invention analyzes the reasons for the decline in the mechanical properties of silicon carbide fiber-reinforced ceramic matrix composites during long-term service in a high-temperature environment. The modulus mismatch and thermal expansion mismatch between the components of the silicon carbide fiber-reinforced ceramic matrix composites under high-temperature conditions result in the easy accumulation of residual thermal stress inside the composites, leading to crack generation, and ultimately causing a significant decline in the mechanical properties of the silicon carbide fiber-reinforced ceramic matrix composites, thus affecting the service life of aeroengines. Based on the above analysis, the silicon carbide fiber-reinforced ceramic matrix composite provided by the present invention optimizes the modulus matching and thermal expansion coefficient matching between the silicon-based multiphase ceramic matrix, the silicon carbide fiber reinforcement phase, and the boron nitride interface layer in the composite by introducing ceramic particles with a particle size of 0.1 - 10 μm into the matrix of the composite. At the same time, the addition of ceramic particles also optimizes the modulus matching and thermal expansion coefficient matching between the phases inside the silicon-based multiphase ceramic matrix, and significantly improves the flexural strength and fracture toughness of the composite; the water and oxygen corrosion-resistant phase in the infiltration reaction product phase has excellent water and oxygen corrosion resistance, ensuring the water and oxygen corrosion resistance of the silicon carbide fiber-reinforced ceramic matrix composite; under the combined action of the silicon-based multiphase ceramic matrix, the boron nitride interface layer, and the silicon carbide fiber reinforcement phase, the silicon carbide fiber-reinforced ceramic matrix composite has both excellent mechanical properties and water and oxygen corrosion resistance.

[0009] In a possible implementation manner, the ceramic particles are selected from at least one of carbide ceramic particles, nitride ceramic particles, and boride ceramic particles.

[0010] Furthermore, the ceramic particles are selected from at least one of silicon carbide ceramic particles, silicon nitride ceramic particles, zirconium carbide ceramic particles, zirconium nitride ceramic particles, and zirconium boride ceramic particles.

[0011] The silicon carbide ceramic particles, silicon nitride ceramic particles, zirconium carbide ceramic particles, zirconium nitride ceramic particles, and zirconium boride ceramic particles have an elastic modulus greater than or equal to that of silicon carbide, are high-temperature resistant, and do not react with the infiltration material.

[0012] In a possible implementation manner, the flexural strength of the silicon carbide fiber-reinforced ceramic matrix composite is ≥700 MPa, and the fracture toughness is ≥20 MPa·m 1 / 2 . By further optimizing the content of the ceramic particle phase introduced into the silicon carbide fiber-reinforced ceramic matrix composite, the flexural strength of the silicon carbide fiber-reinforced ceramic matrix composite is ≥700 MPa, and the fracture toughness is ≥20 MPa·m 1 / 2 , which can better meet the requirements for the mechanical properties of silicon carbide fiber-reinforced ceramic matrix composites in the fields of aeroengines, industrial gas turbines, or space engines.

[0013] In a second aspect, the present invention provides a preparation method for a silicon carbide fiber-reinforced ceramic matrix composite, comprising the following steps:

[0014] S1. A boron nitride interface layer is deposited on a silicon carbide fiber preform by a chemical vapor infiltration process to obtain a silicon carbide fiber composite preform.

[0015] S2. A composite ceramic slurry is impregnated into the silicon carbide fiber composite preform obtained in step S1 by vacuum impregnation and pressure impregnation, and the vacuum impregnation and pressure impregnation are repeated until the weight gain of the silicon carbide fiber composite preform reaches 12 - 15 wt.%, to obtain a composite material preform; the composite ceramic slurry contains 0.5 - 1% sodium carboxymethylcellulose, 20 - 50% boron carbide, 10 - 30% ceramic particles and the balance deionized water by mass percentage, and the particle size of the ceramic particles is 0.1 - 10 μm.

[0016] S3. The composite material preform in step S2 is subjected to reactive melt infiltration in a melt infiltration material to obtain a silicon carbide fiber reinforced ceramic matrix composite.

[0017] The preparation method of the silicon carbide fiber reinforced ceramic matrix composite provided by the present invention introduces ceramic particles with a particle size of 0.1 - 10 μm and boron carbide powder into the matrix of the composite material, and controls the amount of ceramic particles and boron carbide infiltrated into the silicon carbide fiber reinforced ceramic matrix composite by impregnation treatment by controlling the relative contents of ceramic particles, sodium carboxymethylcellulose and boron carbide in the composite ceramic slurry used for impregnation treatment and by controlling the number of impregnation times, optimizes the elastic modulus matching and thermal expansion coefficient matching between the components of the composite material, significantly improves the flexural strength and fracture toughness of the silicon carbide fiber reinforced ceramic matrix composite, and at the same time, boron carbide in the matrix reacts with the melt infiltration material to generate a water - oxygen corrosion resistant phase, so that the prepared silicon carbide fiber reinforced ceramic matrix composite has both excellent mechanical properties and water - oxygen corrosion resistant properties.

[0018] In a possible implementation manner, the silicon carbide fiber preform in step S1 is made by laminating and shaping silicon carbide fiber cloth or by weaving silicon carbide fibers. The two - dimensional laminated silicon carbide fiber preform obtained by stacking silicon carbide fiber cloth at a certain laying angle has high in - plane mechanical properties and is suitable for preparing thin - wall components; using a woven structure preform enables the composite material to meet different mechanical property requirements, and has low manufacturing cost and short production cycle.

[0019] In a possible implementation, the deposition conditions of the boron nitride interface layer in step S1 are as follows: boron trichloride is used as the boron source, ammonia is used as the nitrogen source, the deposition temperature is 600 - 800 °C, and the pressure is 5 - 10 kPa. Using the above deposition gas sources and temperature for the boron nitride interface layer is beneficial to obtaining boron nitride with a uniform interface layer composition and a stoichiometric ratio close to 1:1; using a low pressure of 5 - 10 kPa is beneficial to enhancing the diffusion ability of the deposition gas source between the fiber bundles, especially suitable for silicon carbide fiber preforms with complex braided or laminated fiber shapes, ensuring a uniform thickness of the deposited boron nitride interface layer.

[0020] In a possible implementation, the thickness of the boron nitride interface layer is 500 - 1000 nm. Using a boron nitride interface layer with a thickness of 500 - 1000 nm can not only prevent reaction diffusion between the silicon carbide fiber and the matrix, but also protect the silicon carbide fiber from being eroded by external corrosive atmospheres such as water vapor, and can also maintain a weak interface bond between the silicon carbide fiber and the matrix, improving the toughness of the silicon carbide fiber-reinforced ceramic matrix composite while fully exerting the load-bearing capacity of the silicon carbide fiber.

[0021] In a possible implementation, the process of vacuum impregnation and pressure impregnation in step S2 is as follows: first, place the silicon carbide fiber preform obtained in step S1 in a vacuum dish, evacuate to a pressure ≤ -0.09 MPa in the vacuum dish and maintain for 20 - 30 min, then immerse the silicon carbide fiber preform in the multiphase ceramic slurry and maintain for 20 - 40 min; then place the multiphase ceramic slurry together with the silicon carbide fiber preform in a sealed container, pressurize to 0.6 - 2.0 MPa, maintain for 20 - 120 min and then take out. By combining vacuum impregnation and pressure impregnation processes, first, through a vacuum environment of ≤ -0.09 MPa, the gas in the silicon carbide fiber preform is fully evacuated, avoiding the occurrence of gas blockage during subsequent impregnation treatment and ensuring a smooth impregnation path for the slurry; the 20 - 40 min vacuum impregnation time and the 20 - 120 min pressure impregnation time allow the slurry to fully penetrate into the interior of the silicon carbide fiber preform under the pressure gradient, enabling the slurry to fill micron-sized pores; at the same time, it also avoids insufficient impregnation or uneven impregnation due to too short time, resulting in a large number of unfilled pores inside the composite material. Using a high pressure of 0.6 - 2.0 MPa for pressure impregnation can generate a significant pressure gradient to drive the slurry to quickly penetrate into the interior of the silicon carbide fiber preform, significantly reducing unfilled pores.

[0022] In a possible implementation, the particle size of the boron carbide in step S2 is 0.1 - 10 μm. Boron carbide powder with a particle size of 0.1 - 10 μm can be evenly filled into the silicon carbide fiber preform, which helps to fully react with the infiltration material subsequently.

[0023] In a possible implementation, the process of preparing the composite ceramic slurry in step S2 is as follows: first, dissolve the sodium carboxymethylcellulose in deionized water at a temperature of 60 - 80 °C, and stir evenly to obtain a dispersion solution; then add the boron carbide and the ceramic particles to the dispersion solution to obtain a mixed slurry; the mixed slurry is ball-milled to obtain a uniformly dispersed composite ceramic slurry. Dissolving sodium carboxymethylcellulose in deionized water at 60 - 80 °C, high temperature can accelerate the stretching of its molecular chain and improve the dispersion efficiency, and within the range of 60 - 80 °C, it can also avoid the high-temperature degradation of sodium carboxymethylcellulose, ensuring its full dissolution to form a stable colloid, providing a uniform medium for subsequent particle dispersion; preparing the sodium carboxymethylcellulose dispersion first and then adding boron carbide and ceramic particles step by step can wrap the surface of the particles layer by layer through the electrostatic repulsion and steric hindrance effects of sodium carboxymethylcellulose, inhibiting the sedimentation or agglomeration of particles caused by density differences; during the ball-milling process, the mechanical shear force can break the soft agglomerates of the particles, enabling the boron carbide and the ceramic particles to achieve sub-micron or even nano-scale dispersion.

[0024] Further, the rotation speed of the ball-milling is 200 - 300 r / min, the time is 24 - 36 h, and the size of the corundum balls is 10 - 30 mm. The medium rotation speed range (200 - 300 r / min) can not only provide sufficient mechanical shear force to break the particles but also avoid excessive heating and increased energy consumption caused by high rotation speed (such as > 1000 r / min). The range of 200 - 300 r / min is suitable for processing hard materials such as boron carbide and ceramic particles, reducing the wear of the grinding balls and the equipment and extending their service life; the long-time ball-milling for 24 - 36 h can fully break the soft agglomerates of the particles, enabling the boron carbide or ceramic particles to achieve sub-micron to nano-scale dispersion; compared with large-sized grinding spheres, the corundum balls with a size of 10 - 30 mm have more contact points per unit volume, which can improve the grinding efficiency and shorten the time to reach the target particle size.

[0025] In a possible implementation, the infiltration material in step S3 is selected from one of yttrium silicide alloy, ytterbium silicide alloy, hafnium silicide alloy, molybdenum silicide alloy, and aluminum silicide alloy. After the yttrium silicide alloy, ytterbium silicide alloy, hafnium silicide alloy, molybdenum silicide alloy, and aluminum silicide alloy enter the matrix of the composite material, they can all react with boron carbide to form a phase resistant to water and oxygen corrosion.

[0026] In a possible implementation, the holding temperature for the reaction solution infiltration in step S3 is 1200 - 1500 °C, and the holding time is 30 - 90 min. Within the high-temperature range of 1200 - 1500 °C, it can effectively promote the filling of the pores in the composite material preform by the infiltration material. Combining with the holding time of 30 - 90 min, it can not only ensure the full progress of the infiltration reaction but also avoid the damage to the silicon carbide fibers caused by long-term high temperature.

[0027] Thirdly, the present invention also provides an application of the above silicon carbide fiber reinforced ceramic matrix composite material in the fields of aeroengines, industrial gas turbines or space engines.

[0028] On the basis of conforming to the common knowledge in the art, the above preferred conditions can be combined arbitrarily to obtain various preferred examples of the present invention.

[0029] The reagents and raw materials used in the present invention are all commercially available.

[0030] The positive and progressive effects of the present invention are as follows:

[0031] The silicon carbide fiber reinforced ceramic matrix composite material provided by the present invention has both excellent mechanical properties and water and oxygen corrosion resistance. The water and oxygen corrosion resistant phase in the silicon-based multiphase ceramic matrix can ensure that the silicon carbide fiber reinforced ceramic matrix composite material has excellent water corrosion resistance. The ceramic particles in the silicon-based multiphase ceramic matrix make the modulus matching and thermal expansion coefficient matching between the silicon carbide fiber reinforced phase and the boron nitride interface layer in the silicon carbide fiber reinforced ceramic matrix composite material. At the same time, the addition of ceramic particles also optimizes the modulus matching and thermal expansion coefficient matching between the phases inside the silicon-based multiphase ceramic matrix. Under the interaction of the silicon-based multiphase ceramic matrix, the boron nitride interface layer and the silicon carbide fiber reinforced phase, the flexural strength and fracture toughness of the composite material are significantly improved; the water and oxygen corrosion resistant phase in the infiltration reaction product phase has excellent water and oxygen corrosion resistance, ensuring the water and oxygen corrosion resistance of the silicon carbide fiber reinforced ceramic matrix composite material; under the interaction of the silicon-based multiphase ceramic matrix, the boron nitride interface layer and the silicon carbide fiber reinforced phase, the silicon carbide fiber reinforced ceramic matrix composite material has both excellent mechanical properties and water and oxygen corrosion resistance. Description of the Drawings

[0032] Figure 1 XRD pattern of the silicon carbide particle modified silicon carbide fiber reinforced ceramic matrix composite material prepared in Example 1.

[0033] Figure 2 SEM cross-sectional view of the silicon carbide particle modified silicon carbide fiber reinforced ceramic matrix composite material prepared in Example 1.

[0034] Figure 3 Flexural strength data graph of the composite materials prepared in Examples 1-6 and the comparative example.

[0035] Figure 4 Fracture toughness data graph of the composite materials prepared in Examples 1-4. Detailed Embodiments

[0036] To make the above objects, features, and advantages of the present invention more apparent and understandable, the following provides a detailed description of specific embodiments of the present invention. It should be noted that the following embodiments are only used to illustrate the implementation methods and typical parameters of the present invention, and are not used to limit the parameter range described in the present invention. Reasonable variations derived therefrom are still within the protection scope of the claims of the present invention.

[0037] It should be noted that the endpoints and any values within the ranges disclosed herein are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0038] Unless otherwise defined, all terms, symbols, and other scientific terms used herein are intended to have the same meaning as commonly understood by those skilled in the art to which the present invention pertains. In some cases, terms with conventional understood meanings are defined herein for the purpose of clarification or convenient reference. Such definitions herein should not be construed as indicating a significant difference from the conventional understanding in the art. The technical methods described or cited herein are generally well understood by those skilled in the art and are adopted by conventional methods. Unless otherwise stated, the use of commercially available kits, reagents, and instruments follows the protocols and parameters given by the manufacturers.

[0039] Example 1

[0040] This example provides a silicon carbide particle - modified silicon carbide fiber - reinforced ceramic matrix composite, which is prepared by the following method:

[0041] S1. Using the chemical vapor infiltration process (CVI), deposit a boron nitride interface with a thickness of 600 nm on a two - dimensional laminated silicon carbide fiber preform. The chemical vapor infiltration process uses boron trichloride as the boron source and ammonia as the nitrogen source, with a deposition temperature of 650 °C and a pressure of 5 kPa;

[0042] S2. Dissolve sodium carboxymethyl cellulose in deionized water, heat it in a water bath to 80 °C and stir magnetically until the sodium carboxymethyl cellulose is uniformly dispersed to obtain a dispersion solution. After the dispersion solution cools, add boron carbide powder and silicon carbide particles to obtain a mixed slurry. The mixed slurry contains 30 wt.% boron carbide powder, 10 wt.% silicon carbide particles, and 1.0 wt.% sodium carboxymethyl cellulose. The particle size range of the boron carbide powder is about 1 - 3 μm, and the particle size of the silicon carbide particles is about 5 μm. Pour the mixed slurry into a ball - milling tank filled with corundum balls with a diameter of 10 - 30 mm and wet - ball - mill for 24 h at a ball - milling speed of 300 r / min to obtain a uniformly dispersed mixed slurry;

[0043] S3. First, perform vacuum impregnation. Place the silicon carbide fiber preform obtained in step S1 into a vacuum dish, evacuate to a pressure in the vacuum dish below -0.09 MPa, and maintain for 30 min. Then immerse the silicon carbide fiber preform in the mixed slurry of step S2 for 30 min. Next, perform pressure impregnation. Place the slurry together with the silicon carbide fiber preform into a closed container, pressurize to 0.8 MPa, maintain for 60 min, then take it out. After drying the surface of the silicon carbide fiber preform, dry it at 70 °C, and repeat the vacuum impregnation and pressure impregnation processes 5 times until the weight gain of the silicon carbide fiber preform reaches 12 - 15 wt.%, obtaining a composite material preform.

[0044] S4. The composite material preform obtained in step S3 is embedded with a yttrium silicate alloy and placed in a graphite crucible, and then sent into a vacuum infiltration furnace for reactive melt infiltration. The holding temperature is 1400 °C and the holding time is 60 min, obtaining a silicon carbide particle - modified silicon carbide fiber - reinforced ceramic matrix composite.

[0045] Example 2

[0046] This example provides a silicon carbide particle - modified silicon carbide fiber - reinforced ceramic matrix composite, which is prepared by the following method:

[0047] S1. Use the chemical vapor infiltration process (CVI) to deposit a boron nitride interface with a thickness of 600 nm on a two - dimensional laminated silicon carbide fiber preform. The chemical vapor infiltration process uses boron trichloride as the boron source and ammonia as the nitrogen source, with a deposition temperature of 650 °C and a pressure of 5 kPa.

[0048] S2. Dissolve sodium carboxymethyl cellulose in deionized water, heat it in a water bath to 80 °C and stir magnetically until the sodium carboxymethyl cellulose is uniformly dispersed to obtain a dispersion solution. After the dispersion solution cools, add boron carbide powder and silicon carbide particles to obtain a mixed slurry. The mixed slurry contains 35 wt.% boron carbide powder, 10 wt.% silicon carbide particles, and 1.0 wt.% sodium carboxymethyl cellulose. The particle size range of the boron carbide powder is about 1 - 3 μm, and the particle size of the silicon carbide particles is about 5 μm. Pour the mixed slurry into a ball - milling tank containing corundum balls with a diameter of 10 - 30 mm and perform wet ball - milling for 24 h at a ball - milling speed of 300 r / min to obtain a uniformly dispersed mixed slurry.

[0049] S3. First, perform vacuum impregnation. Place the silicon carbide fiber preform obtained in step S1 into a vacuum dish, evacuate to a pressure in the vacuum dish lower than -0.09 MPa, and maintain for 30 min. Then immerse the silicon carbide fiber preform in the mixed slurry of step S2 for 30 min. Next, perform pressure impregnation. Place the slurry together with the silicon carbide fiber preform in a closed container, pressurize to 0.8 MPa, maintain for 60 min, then take it out. After drying the surface of the silicon carbide fiber preform, dry it at 70 °C, and repeat the vacuum impregnation and pressure impregnation processes 5 times until the weight gain of the silicon carbide fiber preform reaches 12 - 15 wt.%, obtaining a composite material preform;

[0050] S4. Embed the composite material preform obtained in step 3 with a yttrium silicide alloy, place it in a graphite crucible, and send it into a vacuum infiltration furnace for reactive melt infiltration. The holding temperature is 1400 °C and the holding time is 60 min, obtaining a silicon carbide particle - modified silicon carbide fiber - reinforced ceramic matrix composite.

[0051] Example 3

[0052] This example provides a silicon carbide particle - modified silicon carbide fiber - reinforced ceramic matrix composite, which is prepared by the following method:

[0053] S1. Deposit a boron nitride interface with a thickness of 600 nm on a two - dimensional laminated silicon carbide fiber preform by chemical vapor infiltration (CVI). The chemical vapor infiltration process uses boron trichloride as the boron source and ammonia as the nitrogen source, with a deposition temperature of 650 °C and a pressure of 5 kPa;

[0054] S2. Dissolve sodium carboxymethyl cellulose in deionized water, heat it in a water bath to 80 °C and stir magnetically until the sodium carboxymethyl cellulose is uniformly dispersed to obtain a dispersion solution. After the dispersion solution cools, add boron carbide powder and silicon carbide particles to obtain a mixed slurry. The mixed slurry contains 40 wt.% boron carbide powder, 10 wt.% silicon carbide particles and 1.0 wt.% sodium carboxymethyl cellulose. The particle size range of the boron carbide powder is about 1 - 3 μm, and the particle size of the silicon carbide particles is about 5 μm. Pour the mixed slurry into a ball - milling tank containing corundum balls with a diameter of 10 - 30 mm and perform wet ball - milling for 24 h at a ball - milling speed of 300 r / min to obtain a uniformly dispersed mixed slurry;

[0055] S3. First, perform vacuum impregnation. Place the silicon carbide fiber preform obtained in step S1 into a vacuum dish, evacuate to a pressure below -0.09 MPa in the vacuum dish and maintain for 30 min. Then immerse the silicon carbide fiber preform into the mixed slurry in step S2 and keep for 30 min. Next, perform pressure impregnation. Place the slurry together with the silicon carbide fiber preform into a closed container, pressurize to 0.8 MPa, keep for 60 min and then take out. After drying the surface of the silicon carbide fiber preform, dry it at 70 °C and repeat the vacuum impregnation and pressure impregnation processes 5 times until the weight gain of the silicon carbide fiber preform reaches 12 - 15 wt.%, obtaining a composite material preform;

[0056] S4. The composite material preform obtained in step S3 is embedded with a yttrium silicate alloy and placed in a graphite crucible, and then sent into a vacuum infiltration furnace for reactive melt infiltration. The holding temperature is 1400 °C and the holding time is 60 min, obtaining a silicon carbide particle - modified silicon carbide fiber - reinforced ceramic matrix composite.

[0057] Example 4

[0058] This example provides a silicon carbide particle - modified silicon carbide fiber - reinforced ceramic matrix composite, which is prepared by the following method:

[0059] S1. Deposit a boron nitride interface with a thickness of 600 nm on a two - dimensional laminated silicon carbide fiber preform by chemical vapor infiltration (CVI). The chemical vapor infiltration process uses boron trichloride as the boron source and ammonia as the nitrogen source, with a deposition temperature of 650 °C and a pressure of 5 kPa;

[0060] S2. Dissolve sodium carboxymethyl cellulose in deionized water, heat it in a water bath to 80 °C and stir magnetically until the sodium carboxymethyl cellulose is uniformly dispersed to obtain a dispersion solution. After the dispersion solution cools, add boron carbide powder and silicon carbide particles to obtain a mixed slurry. The mixed slurry contains 30 wt.% boron carbide powder, 15 wt.% silicon carbide particles and 1.0 wt.% sodium carboxymethyl cellulose. The particle size range of the boron carbide powder is about 1 - 3 μm and the particle size of the silicon carbide particles is about 5 μm. Pour the mixed slurry into a ball - milling tank containing corundum balls with a diameter of 10 - 30 mm and perform wet ball - milling for 24 h at a ball - milling speed of 300 r / min to obtain a uniformly dispersed mixed slurry;

[0061] S3. First, perform vacuum impregnation. Place the silicon carbide fiber preform obtained in step S1 into a vacuum dish, evacuate to a pressure below -0.09 MPa in the vacuum dish, and maintain for 30 min. Then immerse the silicon carbide fiber preform in the mixed slurry of step S2 for 30 min. Next, perform pressure impregnation. Place the slurry together with the silicon carbide fiber preform in a closed container, pressurize to 0.8 MPa, maintain for 60 min and then take out. After drying the surface of the silicon carbide fiber preform, dry it at 70 °C, and repeat the vacuum impregnation and pressure impregnation processes 5 times until the weight gain of the silicon carbide fiber preform reaches 12 - 15 wt.%, obtaining a composite material preform;

[0062] S4. The composite material preform obtained in step S3 is embedded with a yttrium silicate alloy and placed in a graphite crucible, and then sent into a vacuum infiltration furnace for reactive melt infiltration. The holding temperature is 1400 °C and the holding time is 60 min, obtaining a silicon carbide particle - modified silicon carbide fiber - reinforced ceramic matrix composite.

[0063] Example 5

[0064] This example provides a silicon nitride particle - modified silicon carbide fiber - reinforced ceramic matrix composite, which is prepared by the following method:

[0065] S1. Deposit a boron nitride interface with a thickness of 600 nm on a two - dimensional laminated silicon carbide fiber preform by chemical vapor infiltration (CVI). The chemical vapor infiltration process uses boron trichloride as the boron source and ammonia as the nitrogen source, with a deposition temperature of 650 °C and a pressure of 5 kPa;

[0066] S2. Dissolve sodium carboxymethyl cellulose in deionized water, heat in a water bath to 80 °C and stir magnetically until sodium carboxymethyl cellulose is uniformly dispersed to obtain a dispersion solution. After the dispersion solution cools, add boron carbide powder and silicon nitride particles to obtain a mixed slurry. The mixed slurry contains 30 wt.% boron carbide powder, 10 wt.% silicon nitride particles and 1.0 wt.% sodium carboxymethyl cellulose. The particle size range of the boron carbide powder is about 1 - 3 μm, and the particle size of the silicon nitride particles is about 1 - 3 μm. Pour the mixed slurry into a ball - milling tank containing corundum balls with a diameter of 10 - 30 mm and perform wet ball - milling for 24 h at a ball - milling speed of 300 r / min to obtain a uniformly dispersed mixed slurry;

[0067] S3. First, perform vacuum impregnation. Put the silicon carbide fiber preform obtained in step S1 into a vacuum dish, evacuate to a pressure in the vacuum dish lower than -0.09 MPa, and maintain for 30 min. Then immerse the silicon carbide fiber preform in the mixed slurry of step S2 for 30 min. Next, perform pressure impregnation. Place the slurry together with the silicon carbide fiber preform in a sealed container, pressurize to 0.8 MPa, keep for 60 min and then take it out. After drying the surface of the silicon carbide fiber preform, dry it at 70 °C and repeat the vacuum impregnation and pressure impregnation processes 5 times until the weight gain of the silicon carbide fiber preform reaches 12 - 15 wt.%, obtaining a composite preform.

[0068] S4. The composite preform obtained in step S3 is embedded with a yttrium silicide alloy and placed in a graphite crucible, and then sent into a vacuum infiltration furnace for reactive melt infiltration. The holding temperature is 1400 °C and the holding time is 60 min, obtaining a silicon nitride particle - modified silicon carbide fiber - reinforced ceramic matrix composite.

[0069] Example 6

[0070] This example provides a zirconium carbide particle - modified silicon carbide fiber - reinforced ceramic matrix composite, which is prepared by the following method:

[0071] S1. Deposit a boron nitride interface with a thickness of 600 nm on a two - dimensional laminated silicon carbide fiber preform by chemical vapor infiltration (CVI). The chemical vapor infiltration process uses boron trichloride as the boron source and ammonia as the nitrogen source, with a deposition temperature of 650 °C and a pressure of 5 kPa.

[0072] S2. Dissolve sodium carboxymethyl cellulose in deionized water, heat it in a water bath to 80 °C and stir magnetically until the sodium carboxymethyl cellulose is uniformly dispersed to obtain a dispersion solution. After the dispersion solution cools, add boron carbide powder and zirconium carbide particles to obtain a mixed slurry. The mixed slurry contains 30 wt.% boron carbide powder, 20 wt.% zirconium carbide particles and 1.0 wt.% sodium carboxymethyl cellulose. The particle size range of the boron carbide powder is about 1 - 3 μm, and the particle size of the zirconium carbide particles is about 2 - 5 μm. Pour the mixed slurry into a ball - milling tank containing corundum balls with a diameter of 10 - 30 mm and perform wet ball - milling for 24 h at a ball - milling speed of 300 r / min to obtain a uniformly dispersed mixed slurry.

[0073] S3. First, perform vacuum impregnation. Place the silicon carbide fiber preform obtained in step S1 into a vacuum dish, evacuate to a pressure below -0.09 MPa in the vacuum dish and maintain for 30 min. Then immerse the silicon carbide fiber preform into the mixed slurry in step S2 for 30 min. Next, perform pressure impregnation. Place the slurry together with the silicon carbide fiber preform into a closed container, pressurize to 0.8 MPa, hold for 60 min and then take out. After drying the surface of the silicon carbide fiber preform, dry it at 70 °C, and repeat the vacuum impregnation and pressure impregnation processes 5 times until the weight gain of the silicon carbide fiber preform reaches 12 - 15 wt.%, obtaining a composite material preform;

[0074] S4. The composite material preform obtained in step S3 is embedded with a yttrium silicide alloy and placed into a graphite crucible, and then sent into a vacuum infiltration furnace for reactive melt infiltration. The holding temperature is 1400 °C and the holding time is 60 min, obtaining a zirconium carbide particle - modified silicon carbide fiber - reinforced ceramic matrix composite.

[0075] Comparative Example 1

[0076] This comparative example provides a SiC f / Si - Y - B - C composite material, which is prepared by the following method:

[0077] S1. Deposit a boron nitride interface with a thickness of 600 nm on a two - dimensional laminated silicon carbide fiber preform by chemical vapor infiltration (CVI). The chemical vapor infiltration process uses boron trichloride as the boron source and ammonia as the nitrogen source, with a deposition temperature of 650 °C and a pressure of 5 kPa. Then, deposit a certain amount of silicon carbide matrix by the CVI process. Use trichloromethylsilane (CH3SiCl3, abbreviated as MTS) as the gas source, Ar as the dilution gas, and high - purity hydrogen as the carrier gas for trichloromethylsilane. The deposition temperature is 1000 °C and the pressure is 5 kPa, preparing a porous SiC 3 / SiC preform with a density of about 1.9 g / cm f / SiC preform;

[0078] S2. Dissolve sodium carboxymethylcellulose in deionized water, heat it to 80 °C in a water bath and stir magnetically until sodium carboxymethylcellulose is evenly dispersed to obtain a dispersion solution. After the dispersion solution cools, add boron carbide powder to obtain a boron carbide slurry. The boron carbide slurry contains 30 wt.% boron carbide powder and 1.0 wt.% sodium carboxymethylcellulose. Pour the boron carbide slurry into a ball - milling tank containing corundum balls with a diameter of 10 - 30 mm and perform wet ball - milling for 24 h at a ball - milling speed of 200 r / min to obtain a uniformly dispersed boron carbide slurry;

[0079] S3. The porous SiC in step S1 fPut the SiC / SiC preform into a vacuum dish, evacuate to a pressure below -0.09 MPa in the vacuum dish, and maintain for 30 min; then place the porous SiC f / SiC preform into the boron carbide slurry in step S2, and keep for 30 min; then perform pressure impregnation, and place the slurry together with the porous SiC f / SiC preform into a closed container, pressurize to 0.8 MPa, take it out after maintaining for 30 min, and dry and bake the surface of the porous SiC f / SiC preform, and repeat the vacuum impregnation and pressure impregnation processes 5 times until the weight gain of the composite billet reaches 10 - 13 wt.%, to obtain a composite preform;

[0080] S4. Using the embedding method, place the composite preform prepared in step S3 and the Si - Y alloy powder in a graphite crucible, send it into a vacuum infiltration furnace for reactive melt infiltration, keep the temperature at 1350 °C for 60 min, to obtain SiC f / Si - Y - B - C composite material.

[0081] Characterize and test the composite materials prepared in Examples 1 - 6 and Comparative Example 1, and the results are as follows:

[0082] Figure 1 It is the XRD pattern of the silicon carbide particle - modified silicon carbide fiber - reinforced ceramic matrix composite material prepared in Example 1. As can be seen from the figure, the composite material is mainly composed of SiC, Si, YSi2, and YB4, where YB4 is formed by the reaction of YSi2 and B4C; SiC includes SiC ceramic particles introduced by slurry impregnation and SiC formed by infiltration reaction, YSi2 remains after the infiltration reaction, and Si includes the residual Si of the Si - Y alloy after the infiltration reaction and the Si phase formed by the infiltration reaction.

[0083] Figure 2 It is the SEM image of the cross - section of the silicon carbide particle - modified silicon carbide fiber - reinforced ceramic matrix composite material prepared in Example 1. Figure 2 (a) and Figure 2 (b) are the SEM images of two different regions of the composite material respectively. In the matrix of the composite material, each phase is evenly distributed. Figure 2 The dark - gray region in (a) is the silicon carbide ceramic particle phase (SI SiC), and the light - gray region is the Si phase formed by the infiltration reaction. It can be seen that the SiC particles introduced by slurry impregnation are dispersed in the Si phase in this region. Figure 2In (b), the medium-dark gray area is the SiC ceramic particle phase (SI SiC) introduced by slurry impregnation, the bright white area is the YSi2 phase (YSi2), the light gray area is the SiC phase (RMI SiC) formed by infiltration reaction, YB4 is mixed in the RMI SiC phase, and the black area is the generated B 12 (C,Si,B)3 phase, it can be seen that the generated B in this area 12 (C,Si,B)3 phase, the SiC particle phase introduced by slurry impregnation, and the residual YSi2 phase are embedded in the SiC phase formed by RMI reaction.

[0084] Figure 3 It is the flexural strength data graph of the composites prepared in Examples 1-6 and Comparative Example 1. It can be seen from the figure that the flexural strength of the ceramic particle-modified silicon carbide fiber-reinforced ceramic matrix composites prepared in Examples 1-6 is significantly higher than that of the unmodified SiC in Comparative Example 1 f / Si-Y-B-C composite material. The flexural strength of the SiC particle-modified silicon carbide fiber-reinforced ceramic matrix composite prepared in Example 1 reached a maximum of 722.3 MPa, compared with the flexural strength value of 508.3 MPa of the SiC f / Si-Y-B-C composite material, an increase of 42.1%; the flexural strength of the composites modified with SiC particles in Examples 1-4 is higher than that of the composites modified with Si3N4 particles and ZrC particles. The specific values of the flexural strength of the composites prepared in Examples 1-6 and Comparative Example 1 are shown in Table 1 below.

[0085] Table 1 Flexural strength of the composites prepared in Examples 1-6 and Comparative Example 1

[0086]

[0087] Figure 4 It is the fracture toughness data graph of the composites prepared in Examples 1-4. It can be seen from the figure that in each example, the fracture toughness of Example 1 reached a maximum of 23.63 MPa·m 1 / 2 . The specific values of the fracture toughness data of the composites prepared in Examples 1-4 are shown in Table 2 below.

[0088] Table 2 Fracture toughness of the composites prepared in Examples 1-4

[0089]

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A silicon carbide fiber-reinforced ceramic matrix composite material, characterized in that, It includes a silicon carbide fiber reinforcement phase, a boron nitride interface layer, and a silicon-based composite ceramic matrix from the inside out. The phase composition of the silicon-based composite ceramic matrix includes an infiltration reaction product phase, an introduced ceramic particle phase, and a silicon-containing binary alloy phase. The alloying element in the silicon-containing binary alloy phase is any one of yttrium, ytterbium, hafnium, molybdenum, and aluminum. The ceramic particles are selected from at least one of silicon carbide ceramic particles, zirconium carbide ceramic particles, zirconium nitride ceramic particles, and zirconium boride ceramic particles. The infiltration reaction product phase includes a water and oxygen corrosion-resistant phase, a silicon phase, a silicon carbide phase, and a boride phase. The water and oxygen corrosion-resistant phase includes a compound of boron and any one of the elements yttrium, ytterbium, hafnium, molybdenum, and aluminum. The boride phase includes B 12 (C,Si,B)3. The particle size of the ceramic particles in the ceramic particle phase is 0.1 - 10 μm. The flexural strength of the silicon carbide fiber-reinforced ceramic matrix composite is ≥600 MPa, and the fracture toughness is ≥19 MPa·m 1 / 2 .

2. The silicon carbide fiber-reinforced ceramic matrix composite material according to claim 1, characterized in that, The flexural strength of the silicon carbide fiber-reinforced ceramic matrix composite is ≥ 700 MPa, and the fracture toughness is ≥ 20 MPa·m 1 / 2 .

3. A method for preparing a silicon carbide fiber-reinforced ceramic matrix composite material as described in claim 1 or 2, characterized in that, It includes the following steps: S1. Adopt the chemical vapor infiltration process to deposit a boron nitride interface layer on a silicon carbide fiber preform to obtain a silicon carbide fiber composite preform; S2. Adopt vacuum impregnation and pressure impregnation to impregnate a composite ceramic slurry into the silicon carbide fiber composite preform obtained in step S1 until the weight of the silicon carbide fiber composite preform increases by 12 - 15 wt.%, to obtain a composite material preform; the composite ceramic slurry contains 0.5 - 1% sodium carboxymethylcellulose, 20 - 50% boron carbide, 10 - 30% ceramic particles and the balance deionized water by mass percentage, and the particle size of the ceramic particles is 0.1 - 10 μm; S3. React the composite material preform described in step S2 in a melt infiltration material by reactive melt infiltration to obtain a silicon carbide fiber reinforced ceramic matrix composite.

4. The preparation method of the silicon carbide fiber reinforced ceramic matrix composite material according to claim 3, characterized in that The silicon carbide fiber preform described in step S1 is made by laminating and shaping silicon carbide fiber cloth or by weaving silicon carbide fibers; And / or, the deposition conditions of the boron nitride interface layer in step S1 are that boron trichloride is used as the boron source, ammonia is used as the nitrogen source, the deposition temperature is 600 - 800 °C, and the pressure is 5 - 10 kPa; And / or, the thickness of the boron nitride interface layer is 500 - 1000 nm.

5. The preparation method of the silicon carbide fiber reinforced ceramic matrix composite material according to claim 3, wherein, The process of the vacuum impregnation and pressure impregnation in step S2 is to first place the silicon carbide fiber preform obtained in step S1 in a vacuum dish, evacuate to a pressure ≤ -0.09 MPa in the vacuum dish and maintain for 20 - 30 min, then immerse the silicon carbide fiber preform in the composite ceramic slurry and maintain for 20 - 40 min; then place the composite ceramic slurry together with the silicon carbide fiber preform in a closed container, pressurize to 0.6 - 2.0 MPa, maintain for 20 - 120 min and then take out; And / or, the particle size of the boron carbide in step S2 is 0.1 - 10 μm; And / or, the preparation process of the composite ceramic slurry in step S2 is to first dissolve the sodium carboxymethylcellulose in deionized water at a temperature of 60 - 80 °C, stir evenly to obtain a dispersion solution; then add the boron carbide and the ceramic particles to the dispersion solution to obtain a mixed slurry; the mixed slurry is ball-milled to obtain a uniformly dispersed composite ceramic slurry.

6. The preparation method of the silicon carbide fiber-reinforced ceramic matrix composite material according to claim 5, characterized in that, The rotation speed of the ball milling is 200 - 300 r / min, the time is 24 - 36 h, and the size of the corundum balls is 10 - 30 mm.

7. The preparation method of the silicon carbide fiber reinforced ceramic matrix composite material according to claim 3, characterized in that, The melt infiltration material in step S3 is selected from at least one of yttrium silicide alloy, ytterbium silicide alloy, hafnium silicide alloy, molybdenum silicide alloy and aluminum silicide alloy; And / or, the holding temperature of the reactive melt infiltration in step S3 is 1200 - 1500 °C, and the holding time is 30 - 90 min.

8. The application of the silicon carbide fiber reinforced ceramic matrix composite according to claim 1 or 2 in the fields of aeroengines, industrial gas turbines or space engines.

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