In-situ self-grown ultrafine layered TiC x Method for reinforcing si c composites

Abstract

The application discloses in-situ self-grown ultrafine layered TiC x A preparation method of reinforced SiC composite material. Ti3AlC2 and SiC powder are blended, high-energy ball milling, drying and sieving are carried out to obtain mixed powder, green compacts are formed by molding, and then hot-pressing sintering is carried out. The application utilizes the structure degeneration characteristics of Ti3AlC2 to form TiC in-situ in the SiC ceramic matrix, which has good interface wettability and pure interface x A ceramic dispersion reinforcement body is obtained, and the in-situ self-grown layered TiC x Ultrafine particle reinforced SiC composite material; compared with the interface wettability of externally added reinforcement and ceramic matrix, the interface wettability is significantly improved; compared with the fracture toughness of traditional SiC ceramic, the fracture toughness is 2-5 MPa·m 1 / 2 , which is increased to more than 10 MPa·m 1 / 2 , and the structural ceramic is greatly toughened; compared with the preparation process of traditional SiC ceramic, the material is simpler, does not need to add sintering aids, has low sintering temperature and is suitable for large-scale preparation, and the material has great potential in the fields of petrochemical industry, vehicle brake disc, hypersonic aircraft and the like.

Description

Technical Field

[0001] This invention belongs to the field of ceramic matrix composite material preparation technology, specifically relating to an in-situ self-generated ultrafine layered TiC x Methods for preparing reinforced SiC composite materials. Background Technology

[0002] Silicon carbide (SiC) ceramics possess numerous advantages, including low density, high elastic modulus, high strength, wear resistance, corrosion resistance, oxidation resistance, and excellent high-temperature performance. They hold immense application potential in fields such as mechanical seals, wear-resistant bearings, hard cutting tools, advanced refractory materials, aerospace, and bulletproof armor. However, SiC is a highly covalent compound, with strong C-Si bonds accounting for up to 90% of its composition. This can easily lead to stress concentration due to the inability to effectively release internal defects, ultimately resulting in brittle fracture and failure. Furthermore, the excessively strong covalent bonds result in a low self-diffusion coefficient (1.5 × 10⁻⁶) for elements such as C and Si. -10 ~2.5×10 -13 cm 2 / s This also leads to problems such as the difficulty in sintering SiC ceramics and the high difficulty in densification. As a result, the mechanical properties of SiC ceramics are far below the ideal expected value. Its inherent brittleness as a ceramic material leads to defects such as lack of toughness and poor impact resistance, which seriously limit its application in structural materials and related special materials.

[0003] To improve the mechanical properties of SiC ceramics, a second-phase reinforcement, such as fibers, whiskers, or particles, is typically introduced into the matrix. This is achieved by introducing highly tough, high aspect ratio reinforcements with a specific arrangement within the brittle matrix, or by introducing dispersed isotropic reinforcement structures within the matrix. The synergistic effect between these heterogeneous components alleviates localized stress concentrations or improves the material's resistance to crack propagation, thus toughening and strengthening SiC ceramics. However, current research indicates that high aspect ratio whisker or fiber reinforcements often suffer from several drawbacks. These include uncontrollable bonding with the matrix interface, the need for complex coating processes and uneven distribution of the reinforcement, high porosity in the composite material, excessively high sintering temperatures leading to coarse matrix grains, and uncontrolled growth or reaction damage to the reinforcement. These limitations severely restrict the strengthening and toughening effect of such high aspect ratio reinforcements on the ceramic matrix. The use of second-phase particle reinforcement has many advantages, such as high dispersion, uniform distribution, stable and easy-to-control interfacial bonding with the matrix, and high density of composite materials. At the same time, its preparation process is simple and more suitable for the preparation and large-scale production of complex configuration components. However, the existing technology of using traditional non-in-situ synthesis to strengthen and toughen SiC ceramic materials has a series of key problems that are difficult to overcome, such as poor wettability of the heterogeneous interface formed with SiC ceramics, resulting in very limited effect.

[0004] Ti3AlC2 ceramics, as an important member of the MAX phase material family, exhibit unique layered structures that distinguish them from traditional ceramics, including self-lubrication, ease of processing, and high electrical conductivity. Recent studies have confirmed that Ti3AlC2 can not only form highly dispersed, fine-grained, non-stoichiometric TiC in situ within metals or alloys... x The reinforcement, and the interfacial wettability with the metal phase is better with the addition of TiC or other in-situ synthesized TiC. x The reinforcement is significantly improved, resulting in a substantial enhancement of the mechanical properties of the obtained composite material. Currently, research on obtaining in-situ ceramic reinforcements using MAX phase materials has only been conducted in some exploratory work in metal matrix materials, while related research in ceramic matrix materials has not yet been reported. Furthermore, unlike metal materials, ceramic materials, due to their generally strong covalent / ionic bonding characteristics, suffer from problems such as poor wettability of the resulting heterogeneous interfaces even under high temperature / high pressure conditions, unstable interfacial bonding, and even complete non-wetting (only physical interlocking), which often leads to a significant reduction in the mechanical properties of the prepared composite material compared to the expected design. Summary of the Invention

[0005] To address the problems and shortcomings of the existing technology, the purpose of this invention is to provide an in-situ self-generated layered TiC that is highly dense, ultra-tough, high-strength, high-temperature resistant, and corrosion-resistant. x Ultrafine particle reinforced SiC composite material.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] An in-situ self-generated ultrafine layered TiC x Methods for preparing reinforced SiC composite materials include:

[0008] S1. Prepare a mixed powder by mixing Ti3AlC2 powder and β-SiC powder in a certain proportion;

[0009] S2. Add the mixed powder from S1, polyethylene glycol, and anhydrous ethanol to a ball mill jar containing grinding balls in sequence, and place it in a planetary ball mill for high-energy ball milling to obtain a ball mill slurry.

[0010] S3. Take out the ball mill slurry from S2, dry it, and obtain dry powder;

[0011] S4. The dried powder in S3 is crushed, sieved through a mesh of 300 or more, placed into a stainless steel mold, and dry-pressed under a pressure of 15-25MPa for 3-6 minutes to obtain a block blank.

[0012] S5. The bulk blank from S4 is loaded into a graphite mold and placed into a vacuum hot pressing sintering furnace. It is then hot-pressed and sintered in a vacuum or argon atmosphere to obtain the SiC composite material.

[0013] Preferably, the mass fraction of Ti3AlC2 powder in S1 is 20wt%-50wt%, with the remainder being β-SiC powder.

[0014] Preferably, the Ti3AlC2 powder in S1 has a purity of 95%-98% and an average particle size of 40-80 μm, and the β-SiC powder has a purity of ≥98% and an average particle size of less than 1 μm.

[0015] Preferably, in step S2, the ball milling time is 8-12 hours, the ball-to-material ratio is 4:1, and the rotation speed is 280-330 r / min to obtain the ball milled slurry.

[0016] Preferably, in step S3, the ball-milled slurry is dried in an oven at 80-120°C for more than 24 hours to obtain dried powder.

[0017] Preferably, in step S5, the bulk blank is placed in a vacuum atmosphere with a vacuum degree of 1×10⁻⁶. -2 -1×10 -5 Hot pressing and sintering in a Pa or argon positive pressure atmosphere.

[0018] Preferably, the hot pressing sintering parameters in S5 are set as follows: temperature 1500-2000℃, pressure 15-35 MPa, and holding time 1-3 h.

[0019] Preferably, the sintering temperature is 1750-1950℃ and the hot pressing sintering pressure is 20-30MPa.

[0020] Preferably, the heating rate is 5°C / min in the sintering temperature range of 20-100°C, 20-30°C / min in the 100-1200°C range, and 5-10°C / min from 1200°C to the maximum sintering temperature.

[0021] Preferably, the pressurization program is set as follows: when the temperature inside the vacuum hot pressing sintering furnace reaches the predetermined temperature, the pressurization program is started to gradually increase the pressure. After 8-12 minutes, the maximum pressure of 15-35 MPa is reached. After holding the pressure for 1-3 hours, the pressure is released. After 20-40 minutes, the pressure drops to 0 MPa. After the temperature inside the furnace cools to room temperature, the sample is taken out to obtain the SiC composite material.

[0022] The principle of the technical solution: In this invention, the hot-pressing sintering parameters are set to a temperature of 1500-2000℃, a pressure of 15-35 MPa, and a holding time of 1-3 hours to achieve the synthesis and densification of the composite material. The densification process of the ceramic matrix composite material uses low-melting-point elemental aluminum precipitated from Ti3AlC2 at high temperature as a sintering aid. Through liquid-phase sintering, it promotes the expulsion of pores, particle rearrangement, and volume shrinkage, thereby achieving high-density in-situ self-generated TiC. xThe preparation of reinforced SiC composite materials involves no additional sintering aids during the entire sintering process. In this invention, the variation in heating rate at different temperature stages is based on the structural transformation characteristics caused by the breakdown and outward diffusion of weak bonds in the special layered structure of Ti3AlC2 at high temperatures (>1200℃), leading to the formation of the composite. This invention utilizes an in-situ synthesis method where Ti3AlC2 powder serves as both the reinforcement and a precursor for the sintering aid. Through a hot-pressing sintering process, ultrafine layered TiC composites with excellent surface wettability are obtained. x Using particles to toughen and reinforce SiC ceramics solves the technical problems in existing technologies, such as large and unevenly distributed ceramic reinforcement particles, poor wettability between the reinforcement and matrix interface, impurity of the interface leading to low composite material density, excessively high sintering temperature causing reaction between the reinforcement and matrix, and the need to add additional sintering aids leading to the introduction of impurity phases, making it difficult to fully exert the synergistic effect of the reinforcement and matrix on improving the mechanical properties of composite materials.

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

[0024] This invention addresses the problems of traditional SiC ceramics, such as excessively high sintering temperatures (>2100℃), over-reliance on sintering aids (e.g., YAG-based materials), difficulty in densification, and excessive grain growth caused by excessively high sintering temperatures. These issues lead to unsatisfactory overall mechanical properties of SiC ceramics, particularly fracture toughness, a key indicator for structural components. This invention provides a novel in-situ self-generated ultrafine layered TiC... x Preparation methods of reinforced SiC composite materials:

[0025] (1) This invention utilizes the metamorphic properties of the Ti3AlC2 layered structure to form, in situ, a material with ultra-fine dimensions (below submicron level) and a different stoichiometric ratio (TiC) from common (non-)stoichiometry in the SiC matrix at a certain sintering temperature (>1200℃). x TiC particles possess a unique layered structure, excellent surface / interface wettability, and a pure interfacial composition. x A ceramic dispersion reinforcement was used to prepare an in-situ self-generated ultrafine layered TiC with high density, high toughness, high strength, high temperature resistance, and corrosion resistance. x Reinforced SiC composites; significantly improved interfacial wettability between the added reinforcement and the ceramic matrix; and improved fracture toughness (2-5 MPa·m) compared to traditional SiC ceramics. 1 / 2 A significant jump (>10 MPa·m) 1 / 2 The fracture toughness was increased by 2-5 times, achieving efficient toughening and reinforcement, and greatly enhancing its potential as a structural material.

[0026] (2) This invention utilizes the metamorphic properties of the Ti3AlC2 layered structure to induce the self-diffusion of Al atoms to form high-temperature Al elemental at temperatures far below the traditional SiC ceramic sintering temperature (>1200℃). This serves as a sintering aid, effectively promoting pore discharge, particle rearrangement, and volume shrinkage, thereby achieving highly dense in-situ self-generated TiC. x The "low-temperature additive-free" preparation technology for reinforced SiC composites is simple, energy-saving, and emission-reducing, making it suitable for large-scale preparation.

[0027] (3) The novel in-situ self-generated ultrafine layered TiC provided by this invention x Reinforced SiC composites have great potential in fields such as petrochemicals, vehicle brake discs, and hypersonic aircraft.

[0028] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0029] Figure 1 This invention relates to the preparation of in-situ self-generated ultrafine layered TiC x Process flow diagram of reinforced SiC composite materials;

[0030] Figure 2 In-situ self-generated ultrafine layered TiC with different Ti3AlC2 addition ratios x Line graph showing the changes in flexural strength and fracture toughness of reinforced SiC composites;

[0031] Figure 3 In-situ self-generated ultrafine layered TiC provided at different sintering temperatures x Line graph showing the changes in flexural strength and fracture toughness of reinforced SiC composites;

[0032] Figure 4 The in-situ self-generated ultrafine layered TiC provided in Example 1 x Scanning electron microscope (SEM) image of the polished surface of the reinforced SiC composite material;

[0033] Figure 5 The in-situ self-generated ultrafine layered TiC provided in Example 1 x Scanning electron microscope backscattered image (BSD-SEM) of polished surface of reinforced SiC composite material;

[0034] Figure 6 The in-situ self-generated ultrafine layered TiC provided in Example 1 x Low-magnification scanning electron backscattered image (BSD-SEM) of the bending fracture surface of reinforced SiC composite material;

[0035] Figure 7The in-situ self-generated ultrafine layered TiC provided in Example 1 x High-magnification scanning electron backscattered image (BSD-SEM) of the bending fracture surface of reinforced SiC composite material;

[0036] Figure 8 The in-situ self-generated ultrafine layered TiC provided in Examples 1-3 x X-ray characteristic diffraction peak pattern (XRD) of reinforced SiC composite material. Detailed Implementation

[0037] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0038] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0039] Unless otherwise specified, all raw materials used in this invention are commercially available products in the art.

[0040] Example 1: An in-situ self-generated ultrafine layered TiC x The method for preparing reinforced SiC composite materials includes the following steps:

[0041] S1. Prepare a mixed powder by mixing 20wt% Ti3AlC2 powder (purity 96%, average particle size 54μm) and 80wt% β-SiC powder (purity 98%, average particle size 1μm);

[0042] S2. The mixed powder from S1, along with appropriate amounts of polyethylene glycol and anhydrous ethanol, are sequentially added to a ball mill jar containing grinding balls. A certain number of SiC grinding balls are then added to the ball mill jar, with a ball-to-powder ratio of 4:1. The ball mill jar is then placed in a planetary ball mill for high-energy ball milling. The ball milling speed is set to 280 r / min, and the ball milling time is 12 h to prepare a mixed ball milling slurry.

[0043] S3. Take out the ball mill slurry from S2 and dry it in an oven at 80℃ for 48 hours to obtain dried powder.

[0044] S4. The dried powder in S3 is crushed, sieved through a 300-mesh sieve, placed into a stainless steel mold with a mold size of Ф=50mm, and held under pressure of 20MPa for 6min to obtain a block blank.

[0045] S5. The bulk blank from S4 is loaded into a graphite mold and placed in a vacuum hot-pressing sintering furnace. Sintering is performed in an argon positive pressure atmosphere at a temperature of 1600℃ and a pressure of 25MPa. The heating program is set as follows: a heating rate of 5℃ / min in the 20-100℃ range, a heating rate of 20℃ / min in the 100-1200℃ range, and a heating rate of 10℃ / min in the 1200-1600℃ range, with a holding time of 1 hour. The pressurization program is set as follows: when the furnace temperature reaches 1500℃, the pressurization program is started to gradually increase the pressure, reaching the maximum pressure of 25MPa after 10 minutes. After holding for 1 hour, the pressure is released, and after 30 minutes, the pressure drops to 0MPa. After the furnace temperature cools to room temperature, the sample is removed, thus obtaining the corresponding in-situ self-generated ultrafine layered TiC. x Reinforced SiC composites.

[0046] Example 2: An in-situ self-generated ultrafine layered TiC x The method for preparing reinforced SiC composite materials includes the following steps:

[0047] S1. Prepare a mixed powder by mixing 30wt% Ti3AlC2 powder (purity 97%, average particle size 48μm) and 70wt% β-SiC powder (purity 98%, average particle size 800nm);

[0048] S2. The mixed powder from S1, along with appropriate amounts of polyethylene glycol and anhydrous ethanol, are sequentially added to a ball mill jar containing grinding balls. A certain number of SiC grinding balls are then added to the ball mill jar, with a ball-to-powder ratio of 4:1. The ball mill jar is then placed in a planetary ball mill for high-energy ball milling. The ball milling speed is set to 300 r / min, and the ball milling time is 10 h to prepare a mixed ball milling slurry.

[0049] S3. Take out the ball mill slurry from S2 and dry it in an oven at 100℃ for 36 hours to obtain dried powder.

[0050] S4. The dried powder in S3 is crushed, sieved through a 350-mesh sieve, placed into a stainless steel mold with a mold size of Ф=50mm, and held under pressure of 20MPa for 5min to obtain a block blank.

[0051] S5. The bulk blank from S4 is loaded into a graphite mold and placed in a vacuum hot-pressing sintering furnace. Sintering is performed in an argon positive pressure atmosphere at a temperature of 1800℃ and a pressure of 30MPa. The heating program is set as follows: a heating rate of 5℃ / min in the 20-100℃ range, a heating rate of 20℃ / min in the 100-1200℃ range, and a heating rate of 10℃ / min in the 1200-1600℃ range, with a holding time of 1 hour. The pressurization program is set as follows: when the furnace temperature reaches 1700℃, the pressurization program is started to gradually increase the pressure, reaching the maximum pressure of 30MPa after 10 minutes. After holding for 1 hour, the pressure is released, and after 30 minutes, the pressure drops to 0MPa. After the furnace temperature cools to room temperature, the sample is removed, thus obtaining the corresponding in-situ self-generated ultrafine layered TiC. x Reinforced SiC composites.

[0052] Example 3: An in-situ self-generated ultrafine layered TiC x The method for preparing reinforced SiC composite materials includes the following steps:

[0053] S1. Prepare a mixed powder by mixing 40wt% Ti3AlC2 powder (purity 98%, average particle size 40μm) and 60wt% β-SiC powder (purity 99%, average particle size 500nm);

[0054] S2. The mixed powder from S1, along with appropriate amounts of polyethylene glycol and anhydrous ethanol, are sequentially added to a ball mill jar containing grinding balls. A certain number of SiC grinding balls are then added to the ball mill jar, with a ball-to-powder ratio of 4:1. The ball mill jar is then placed in a planetary ball mill for high-energy ball milling. The ball milling speed is set to 320 r / min, and the ball milling time is 8 h to prepare a mixed ball milling slurry.

[0055] S3. Take out the ball mill slurry from S2 and dry it in an oven at 120℃ for 24 hours to obtain dried powder.

[0056] S4. The dried powder in S3 is crushed, sieved through a 400-mesh sieve, placed into a stainless steel mold with a mold size of Ф=50mm, and held under pressure of 25MPa for 3min to obtain a block blank.

[0057] S5. The bulk blank from S4 is loaded into a graphite mold and placed in a vacuum hot-pressing sintering furnace. Sintering is performed in an argon positive pressure atmosphere at a temperature of 1950℃ and a pressure of 35MPa. The heating program is set as follows: a heating rate of 5℃ / min in the 20-100℃ range, a heating rate of 20℃ / min in the 100-1200℃ range, and a heating rate of 10℃ / min in the 1200-1600℃ range, with a holding time of 1 hour. The pressurization program is set as follows: when the furnace temperature reaches 1850℃, the pressurization program is started to gradually increase the pressure, reaching the maximum pressure of 35MPa after 10 minutes. After holding for 1 hour, the pressure is released, and after 30 minutes, the pressure drops to 0MPa. After the furnace temperature cools to room temperature, the sample is removed, thus obtaining the corresponding in-situ self-generated ultrafine layered TiC. x Reinforced SiC composites.

[0058] The following experiments were conducted to evaluate the in-situ self-generated ultrafine layered TiC provided in each embodiment. x The effect of reinforcing SiC composite materials was verified:

[0059] (1) In-situ self-generated ultrafine layered TiC with different Ti3AlC2 addition ratios x Reinforced SiC composites and in-situ self-generated ultrafine layered TiC provided at different sintering temperatures x Mechanical properties of reinforced SiC composites were tested, and the test results are as follows: Figure 2 and Figure 3 .

[0060] (2) The in-situ self-generated ultrafine layered TiC provided in Example 1 x Surface morphology of reinforced SiC composites was observed, and the results are as follows: Figures 4-7 .

[0061] (3) X-ray diffraction experiments were conducted on the SiC composite materials prepared in Examples 1-3. The experimental results are as follows: Figure 8 As shown.

[0062] The test results are as follows:

[0063] (1) By Figure 2 It can be seen that different proportions of Ti3AlC2 addition affect the in-situ self-generated ultrafine layered TiC x The addition of Ti3AlC2 significantly affects the flexural strength and fracture toughness of SiC composites. The composite prepared with 35 wt% Ti3AlC2 exhibits a very high flexural strength of 590 MPa; while the composite with 40 wt% Ti3AlC2 achieves an even higher fracture toughness of 10.3 MPa·m. 1 / 2 Because SiC ceramics typically have extremely poor or even almost no toughness (fracture toughness value 2-4 MPa·m), 1 / 2Therefore, the SiC-based composite materials prepared by this method exhibit significantly higher toughness than ordinary SiC ceramics (10 vs 2-4 MPa·m). 1 / 2 The performance is improved by 2 to 5 times or more.

[0064] Depend on Figure 3 It can be seen that the sintering temperature has a significant impact on the in-situ self-generated ultrafine layered TiC. x The addition of Ti3AlC2 significantly affects the flexural strength and fracture toughness of SiC composites. In the composite material prepared with 35wt% Ti3AlC2, it was clearly observed that within the sintering temperature range of 1550℃ to 1950℃, the composite material prepared at 1850℃ exhibited the highest values ​​(590 MPa and 8.9 MPa·m) in both flexural strength and fracture toughness compared to samples sintered at other temperatures. 1 / 2 This indicates that the composite material obtained at this temperature has the best overall mechanical properties.

[0065] (2) By Figures 4-7 The provided SEM results show that the in-situ self-generated ultrafine layered TiC prepared in Example 1 of this invention... x The surface of the reinforced SiC composite material is very smooth with no obvious pores or microcracks, resulting in an ultrafine reinforced TiC. x The particles are extremely small (approximately a few micrometers to submicrometers) and dispersed within the SiC matrix, while TiC... x The SiC two-phase heterogeneous interface exhibits a very tight bond, a pure interface region, no obvious voids, and clear wetting and bonding characteristics. Overall, the composite material has a dense structure, uniform phase distribution, no surface protrusions or graininess, and low surface roughness.

[0066] (3) Figure 8 XDR results show that under the process conditions of sintering temperature of 1550-1950℃, sintering pressure of 25-35MPa, and holding time of 1h, the final product obtained regardless of the addition amount of 20wt%, 30wt%, or 40wt% Ti3AlC2 powder has a very pure phase composition, consisting almost entirely of in-situ generated TiC. x No other obvious impurity phases (such as Al2O3, TiAl, etc. that may be generated) were detected in the reinforcing phase and the originally added SiC matrix phase. x Or Ti2AlC, etc.

[0067] By using Ti3AlC2 ceramic as a precursor, a TiC matrix with excellent interfacial wettability and a pure interface is formed in the ceramic matrix at a sintering temperature far lower than that of traditional SiC ceramics. x The ceramic dispersion reinforcement ultimately yielded a highly dense, high-strength, and high-toughness in-situ self-generated ultrafine layered TiC. xReinforced SiC Composites. The SiC-based composite material preparation method of the present invention can solve the problems of high energy consumption in the preparation of traditional SiC ceramics and their composites, the problem of impurity phase contamination introduced by adding sintering aids, the problem of poor bonding at ceramic / ceramic heterostructure interfaces, the common problems of coarse particles and uneven distribution of ceramic reinforcements in the ceramic matrix, and the problems of difficulty in densification, insufficient strength, and extremely poor toughness in traditional SiC ceramics. In summary, the preparation method provided by the present invention can, within the relevant process parameter range, produce a novel in-situ self-generated ultrafine layered TiC with pure phase, high density, high toughness, and high strength. x Reinforced SiC composites.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. An in-situ self-generated ultrafine layered TiC x The method for preparing reinforced SiC composite materials is characterized by, Includes the following steps: S1. Prepare a mixed powder by mixing Ti3AlC2 powder and β-SiC powder in a certain proportion; S2. Add the mixed powder from S1, polyethylene glycol, and anhydrous ethanol to a ball mill jar containing grinding balls in sequence, and place it in a planetary ball mill for high-energy ball milling to obtain a ball mill slurry. S3. Take out the ball mill slurry from S2, dry it, and obtain dry powder; S4. The dried powder in S3 is crushed, sieved through a mesh of 300 or more, placed into a stainless steel mold, and dry-pressed under a pressure of 15-25MPa for 3-6 minutes to obtain a block blank. S5. The bulk blank in S4 is loaded into a graphite mold and placed into a vacuum hot pressing sintering furnace. It is then hot-pressed and sintered in a vacuum or argon atmosphere to obtain the SiC composite material. The mass fraction of Ti3AlC2 powder in S1 is 30wt%-50wt%, with the balance being β-SiC powder; In S1, the purity of Ti3AlC2 powder is 95%-98% and the average particle size is 40-80 μm, while the purity of β-SiC powder is ≥98% and the average particle size is less than 1 μm. In S2, the ball milling time is 8-12 hours, the ball-to-material ratio is 4:1, and the rotation speed is 280-330 r / min to obtain the ball milling slurry. In S5, the hot pressing sintering parameters are set as follows: sintering temperature 1750-1950℃, hot pressing sintering pressure 20-30MPa, and holding time 1-3h.

2. The in-situ self-generated ultrafine layered TiC according to claim 1 x The method for preparing reinforced SiC composite materials is characterized by, In S3, the ball-milled slurry is dried in an oven at 80-120℃ for more than 24 hours to obtain dried powder.

3. The in-situ self-generated ultrafine layered TiC according to claim 1 x The method for preparing reinforced SiC composite materials is characterized by, In S5, the bulk blank is placed in a vacuum atmosphere with a vacuum degree of 1×10⁻⁶. -2 -1×10 -5 Hot pressing and sintering in a Pa or argon positive pressure atmosphere.

4. The in-situ self-generated ultrafine layered TiC according to claim 1 x The method for preparing reinforced SiC composite materials is characterized by, In S5, the heating rate is 5℃ / min in the sintering temperature range of 20-100℃, 20-30℃ / min in the 100-1200℃ range, and 5-10℃ / min from 1200℃ to the maximum sintering temperature.

5. The in-situ self-generated ultrafine layered TiC according to claim 1 x The method for preparing reinforced SiC composite materials is characterized by, In S5, the pressurization program is set as follows: when the temperature inside the vacuum hot pressing sintering furnace reaches the predetermined temperature, the pressurization program is started to gradually increase the pressure. After 8-12 minutes, the maximum pressure of 20-30 MPa is reached. After holding the pressure for 1-3 hours, the pressure is released. After 20-40 minutes, the pressure drops to 0 MPa. After the temperature inside the furnace cools to room temperature, the sample is taken out to obtain the SiC composite material.

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