High-strength diamond-silicon carbide composite ceramic material and method for manufacturing the same

Abstract

The application belongs to the technical field of diamond silicon carbide ceramics, and discloses a high-strength diamond silicon carbide composite ceramic material and a preparation method thereof. The preparation method comprises the following steps: mixing silicon carbide powder and diamond powder in proportion, adding a binder to obtain composite powder with good fluidity; then, a ceramic blank is obtained through dry pressing or isostatic pressing; then, carbon content is increased through high-residual-carbon solution immersion or chemical vapor infiltration treatment; then, high-temperature degreasing treatment is performed on the blank after the carbon-increasing treatment; finally, silicon infiltration reaction sintering is performed to obtain the final high-strength diamond silicon carbide composite ceramic material. The material has high hardness, excellent wear resistance and good mechanical properties, and is suitable for the fields of protective armor, cutting tools and wear-resistant parts.

Description

Technical Field

[0001] This invention belongs to the field of diamond silicon carbide ceramic technology, specifically relating to a high-strength diamond silicon carbide composite ceramic material and its preparation method. Background Technology

[0002] Diamond is the hardest known natural material, with a Vickers hardness of approximately 150 GPa. It possesses excellent physical properties, such as extremely high thermal conductivity, a low coefficient of thermal expansion, high strength, and high wear resistance. Due to these superior properties, diamond is widely used in cutting, abrasives, and high-performance electronic devices. However, diamond has poor oxidation and corrosion resistance, especially in high-temperature or corrosive atmospheres, where its stability is low, limiting its application in certain fields.

[0003] Silicon carbide (SiC) is a common ceramic material with high hardness, good wear resistance, and excellent thermal and chemical stability. Compared to diamond, silicon carbide has better oxidation and corrosion resistance, thus maintaining a longer service life in harsher environments. However, silicon carbide has low toughness and is prone to fracture under impact, therefore, it cannot meet the requirements of certain high-performance applications when used alone.

[0004] To overcome the shortcomings of both diamond and silicon carbide, diamond / silicon carbide composite ceramic materials with excellent comprehensive properties can be developed. This composite material combines the high hardness and high thermal conductivity of diamond with the oxidation and corrosion resistance of silicon carbide, while simultaneously improving the overall toughness and strength of the material. Therefore, it has broad application potential in fields such as protective armor, cutting tools, and wear-resistant components. Currently, there are various methods for preparing diamond / silicon carbide composite ceramic materials, including high-temperature and high-pressure sintering, spark plasma sintering, and hot isostatic pressing. However, these methods typically require high-temperature and high-pressure conditions or complex equipment, and the production process is time-consuming and costly, making large-scale industrial production difficult. Summary of the Invention

[0005] To address the shortcomings mentioned in the background section, the present invention aims to provide a high-strength diamond-silicon carbide composite ceramic material and its preparation method. This method uses silicon carbide powder and diamond powder as main raw materials, mixes them with a binder, and then sequentially performs carburization treatment, high-temperature degreasing, and silicon infiltration reaction sintering to obtain a dense and well-bonded composite ceramic material. This invention effectively combines the high hardness and high thermal conductivity of diamond with the high strength, wear resistance, and corrosion resistance of silicon carbide. It has the advantages of a relatively simple process flow, low equipment requirements, and suitability for industrial production, and can be applied to the fields of protective armor, wear-resistant components, and cutting tools.

[0006] The objective of this invention can be achieved through the following technical solutions: A method for preparing a high-strength diamond-silicon carbide composite ceramic material includes the following steps: S1. Mix silicon carbide powder and diamond powder in a certain proportion, add a binder, and obtain a composite powder with good flowability; S2. The composite powder is placed into a mold to form a ceramic blank; S3. Perform a first high-temperature degreasing treatment on the ceramic blank to remove the binder; S4. The degreased sample is subjected to carbonization treatment, wherein the carbonization treatment is performed by impregnation with a high residual carbon solution or chemical vapor permeation treatment; S5. Perform a second high-temperature degreasing treatment on the carbon-enriched ceramic green body to obtain a degreased green body. The degreasing temperature shall not exceed 1200℃. S6. The degreased green blank is subjected to silicon diffusion reaction sintering to obtain high-strength diamond silicon carbide composite ceramic material.

[0007] More preferably, in step S1, the silicon carbide powder accounts for 30-90 wt% of the total mass of silicon carbide powder and diamond powder, and the diamond powder accounts for 10-70 wt% of the total mass of silicon carbide powder and diamond powder.

[0008] More preferably, in step S1, the amount of binder added is 0.5 to 5 wt% of the total mass of silicon carbide powder and diamond powder, and the binder is selected from one or more of polyvinyl alcohol, polyvinyl butyral, polymethyl methacrylate, polyvinylpyrrolidone, and epoxy resin.

[0009] More preferably, in step S2, the molding is dry pressing and / or isostatic pressing; wherein the molding pressure of dry pressing is 15-100 MPa, and the molding pressure of isostatic pressing is 150-210 MPa.

[0010] More preferably, the high residual carbon solution used in the carbonization treatment in step S4 is selected from one or more of phenolic resin, sucrose, and asphalt resin, and the carburizing medium used in the chemical vapor infiltration is a hydrocarbon gas.

[0011] More preferably, the degreasing temperature is 900~1100℃, the degreasing time is 12~48 hours, and the porosity of the green blank after the second high-temperature heat treatment is 10~60%.

[0012] More preferably, the temperature of the silicon infiltration reaction sintering in step S6 is 1450~1600℃, and the sintering time is 60~120 minutes.

[0013] A high-strength diamond-silicon carbide composite ceramic material, the material comprising a silicon carbide component and a diamond component, wherein the silicon carbide component accounts for 30-90 wt% of the total mass of the material, and the diamond component accounts for 10-70 wt% of the total mass of the material.

[0014] More preferably, the silicon carbide powder has a particle size of 10~300μm and a bulk density of 1.25~1.85 g / cm³; the diamond powder has a particle size of 10~250μm and a bulk density of 1.75~2.05 g / cm³.

[0015] More preferably, the mechanical properties of the high-strength diamond silicon carbide composite ceramic material are a bending strength of 320~560MPa and a hardness of 32~46 GPa.

[0016] The beneficial effects of this invention are: This invention provides a high-strength diamond-silicon carbide composite ceramic material and its preparation method, which effectively combines the performance advantages of both diamond and silicon carbide to obtain a composite ceramic material with high hardness, high strength, wear resistance, and good structural stability. By rationally designing the composite ratio of the two materials, this invention improves upon the insufficient oxidation resistance of single diamond materials and the limited overall performance of single silicon carbide materials while maintaining high hardness, thus achieving complementary performance. Simultaneously, this invention employs a technical route combining powder mixing, molding, carbon enrichment treatment, high-temperature debinding, and silicon infiltration reaction sintering. Carbon enrichment treatment increases the effective carbon content in the green body, allowing for a more complete silicon infiltration reaction, reducing defects and residual porosity, and improving the overall mechanical properties and reliability of the material. The combination of the debinding process and the silicon infiltration reaction sintering process effectively controls the internal pore structure and reaction process of the green body, making it easier for liquid silicon to penetrate into the green body and react with the carbon source to form a bonding phase, enhancing the interfacial bonding strength between diamond particles and the silicon carbide matrix, thereby improving the material's flexural strength, hardness, and wear resistance. Furthermore, the process flow adopted in this invention is relatively simple and does not rely on complex equipment such as high-temperature and high-pressure sintering or spark plasma sintering. It has the advantages of lower equipment requirements, better process controllability, and relatively low production costs, making it more suitable for industrial continuous production and large-scale manufacturing. Attached Figure Description

[0017] The invention will now be further described with reference to the accompanying drawings.

[0018] Figure 1 The bar chart shows the comparison of flexural strength and hardness of ceramic samples from Examples 1-3 and Comparative Examples 1-2. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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.

[0020] Example 1: This example illustrates the specific process for preparing high-strength diamond-silicon carbide composite ceramic materials under conditions of high silicon carbide content and low diamond content.

[0021] S1. Silicon carbide powder with an average particle size D50 of 150 μm and diamond powder with an average particle size D50 of 10 μm are mixed at a mass ratio of 90:10. 1 wt% polyvinyl alcohol is added as a binder based on the total mass of silicon carbide powder and diamond powder. The mixture is then thoroughly mixed to obtain a composite powder with good flowability.

[0022] S2. The obtained composite powder is loaded into a mold for dry pressing at a pressure of 40 MPa; then the dry-pressed green body is subjected to isostatic pressing at a pressure of 200 MPa to obtain a ceramic green body.

[0023] S3. First high-temperature degreasing treatment: The ceramic green body is subjected to a first high-temperature degreasing treatment to remove the binder. The degreasing temperature is 1200℃ and the holding time is 12 h to obtain the green body after the first degreasing.

[0024] S4. The degreased sample is immersed once in a phenolic resin solution to increase the carbon content of the sample, and then dried to obtain a carbon-enriched green body.

[0025] S5. The carbon-enriched green body is subjected to a second high-temperature heat treatment at a temperature of 1200℃ and a holding time of 12 h to remove volatiles and increase the carbon content in the green body, thereby obtaining a degreased green body; the degreased green body has a porosity of 12% and an average pore size of 1 μm.

[0026] S6. The defatted green blank was subjected to silicon infiltration reaction sintering at 1600℃ and held for 1 h to obtain high-strength diamond silicon carbide composite ceramic material.

[0027] Example 2: This example illustrates the specific process for preparing high-strength diamond-silicon carbide composite ceramic materials under a medium silicon carbide to diamond ratio.

[0028] S1. Silicon carbide powder with an average particle size D50 of 120 μm and diamond powder with an average particle size D50 of 50 μm are mixed at a mass ratio of 60:40. 2 wt% of polyvinyl butyral is added as a binder based on the total mass of silicon carbide powder and diamond powder. The mixture is then thoroughly mixed to obtain a composite powder with good flowability.

[0029] S2. The obtained composite powder is loaded into a mold for dry pressing at a pressure of 40 MPa to obtain a ceramic blank.

[0030] S3. The ceramic green body is subjected to a first high-temperature degreasing treatment to remove the binder. The degreasing temperature is 1200℃ and the holding time is 24 h to obtain a green body after the first degreasing.

[0031] S4. The degreased green body is immersed in a phenolic resin solution once to increase the carbon content in the green body, and then dried to obtain a carbon-enriched green body.

[0032] S5. The carbon-enriched green body is subjected to a second high-temperature heat treatment at a temperature of 1200℃ for 24 h to remove volatiles and increase the carbon content in the green body, thereby obtaining a degreased green body; the degreased green body has a porosity of 20% and an average pore size of 5 μm.

[0033] S6. The defatted green blank is subjected to silicon infiltration reaction sintering at 1550℃ for 1 h to obtain a high-strength diamond silicon carbide composite ceramic material.

[0034] Example 3: This example illustrates the specific process of preparing high-strength composite ceramic materials by carbonization and silicon infiltration reaction sintering under conditions of high diamond content.

[0035] S1. Silicon carbide powder with an average particle size D50 of 150 μm and diamond powder with an average particle size D50 of 20 μm are mixed at a mass ratio of 30:70. 1 wt% polyvinyl alcohol is added as a binder based on the total mass of silicon carbide powder and diamond powder. The mixture is then thoroughly mixed to obtain a composite powder with good flowability.

[0036] S2. The obtained composite powder is loaded into a mold for dry pressing at a pressure of 40 MPa; then the dry-pressed green body is subjected to isostatic pressing at a pressure of 200 MPa to obtain a ceramic green body.

[0037] S3. The ceramic blank is subjected to a first high-temperature degreasing treatment to remove the binder. The degreasing temperature is 1200℃ and the holding time is 48 h to obtain a blank after the first degreasing.

[0038] S4. The degreased green body is immersed in a sucrose solution once to increase the carbon content in the green body, and then dried to obtain a carbon-enriched green body.

[0039] S5. The carbon-enriched green body is subjected to a second high-temperature heat treatment at a temperature of 1200℃ and a holding time of 48 h to remove volatiles and increase the carbon content in the green body, thereby obtaining a degreased green body; the degreased green body has a porosity of 30% and an average pore size of 10 μm.

[0040] S6. The defatted green blank is subjected to silicon infiltration reaction sintering at 1550℃ for 2 h to obtain a high-strength diamond silicon carbide composite ceramic material.

[0041] Comparative Example 1: The effect of not performing carbon enrichment treatment on the properties of high-strength diamond silicon carbide composite ceramic materials.

[0042] S1. Silicon carbide powder with an average particle size D50 of 150 μm and diamond powder with an average particle size D50 of 20 μm are mixed at a mass ratio of 30:70. 1 wt% polyvinyl alcohol is added as a binder based on the total mass of silicon carbide powder and diamond powder. The mixture is then thoroughly mixed to obtain a composite powder with good flowability.

[0043] S2. The obtained composite powder is loaded into a mold for dry pressing at a pressure of 40 MPa; then the dry-pressed green body is subjected to isostatic pressing at a pressure of 200 MPa to obtain a ceramic green body.

[0044] S3. The ceramic blank is subjected to a first high-temperature degreasing treatment to remove the binder. The degreasing temperature is 1200℃ and the holding time is 48 h to obtain a blank after the first degreasing.

[0045] S4. The degreased green body is not subjected to sucrose solution impregnation for carbonization, but is directly subjected to high-temperature heat treatment at a temperature of 1200℃ for a holding time of 48 h to obtain the treated green body; the porosity of the treated green body is 30% and the average pore diameter is 10 μm.

[0046] S5. The treated green body is subjected to silicon infiltration reaction sintering at 1550℃ for 2 h to obtain the diamond silicon carbide composite ceramic material of Comparative Example 1.

[0047] Comparative Example 2: The second high-temperature heat treatment was omitted to compare the effect of the second high-temperature heat treatment on the properties of the resulting high-strength diamond silicon carbide composite ceramic material.

[0048] S1. Silicon carbide powder with an average particle size D50 of 150 μm and diamond powder with an average particle size D50 of 20 μm are mixed at a mass ratio of 30:70. 1 wt% polyvinyl alcohol is added as a binder based on the total mass of silicon carbide powder and diamond powder. The mixture is then thoroughly mixed to obtain a composite powder with good flowability.

[0049] S2. The obtained composite powder is loaded into a mold for dry pressing at a pressure of 40 MPa; then the dry-pressed green body is subjected to isostatic pressing at a pressure of 200 MPa to obtain a ceramic green body.

[0050] S3. The ceramic blank is subjected to a first high-temperature degreasing treatment to remove the binder. The degreasing temperature is 1200℃ and the holding time is 48 h to obtain a blank after the first degreasing.

[0051] S4. The degreased green body is immersed in a sucrose solution once to increase the carbon content in the green body, and then dried to obtain a carbon-enriched green body.

[0052] S5. The carbon-enriched green body is directly subjected to silicon infiltration reaction sintering at 1550℃ without a second high-temperature heat treatment, and the holding time is 2 h to obtain the diamond silicon carbide composite ceramic material of Comparative Example 2.

[0053] Performance testing 1. Mechanical property testing Each sample was processed into a standard ceramic specimen. Bending strength was tested according to GB / T 6569-2006 using the three-point bending method. The specimen dimensions were 3mm × 4mm × 36mm, span 30mm, and loading rate 0.5mm / min. The specimen surface was polished to Ra ≤ 0.2μm. Vickers hardness was tested according to GB / T 16534-2009, with a test force of 10kgf and a holding time of 15s. Five valid specimens were tested for each group of samples. After removing outliers, the average value was taken. The results are shown in Table 1.

[0054] Table 1 Mechanical property results

[0055] As shown in Table 1, the high-strength diamond-silicon carbide composite ceramic materials obtained in the embodiments of the present invention exhibit significantly better flexural strength and hardness than the comparative samples, indicating that the process route adopted in the present invention can significantly improve the comprehensive mechanical properties of the materials. Specifically, in Examples 1 to 3, with the optimization of raw material ratios and process parameters, the flexural strength of the materials increased from 320 MPa to 560 MPa, and the hardness increased from 32 GPa to 46 GPa. This indicates that the synergistic effect of carburization treatment, secondary high-temperature heat treatment, and silicon infiltration reaction sintering is beneficial to increasing the effective carbon content in the green body, promoting a more complete silicon infiltration reaction, and improving the internal density and interfacial bonding state of the material. In contrast, Comparative Example 1 did not undergo carburization treatment, and Comparative Example 2 omitted the second high-temperature heat treatment, both resulting in a significant decrease in material strength and hardness. This demonstrates that the carburization step and subsequent heat treatment steps play an important role in improving the structural integrity of the composite ceramic materials, reducing porosity defects, and enhancing mechanical properties.

[0056] 2. Compactness and pore structure testing Each sample was processed into regular 10mm×10mm×10mm blocks, deburred, and dried at 110±5℃ to constant weight (the difference between two weighings ≤0.001g). Bulk density and apparent porosity were determined according to GB / T 25995-2010 using the Archimedes' displacement method with deionized water as the medium, after vacuum impregnation for 30 min. Pore size distribution was determined according to GB / T 21650.1-2008 using the mercury porosimetry method, with a test pressure of 0.001~300MPa and a contact angle of 130°. Three valid samples were tested for each group, and the average value was taken as the final result. The results are shown in Table 2 below.

[0057] Table 2. Results of compactness and pore structure tests

[0058] As shown in Table 2, the bulk density of the high-strength diamond-silicon carbide composite ceramic materials obtained in the embodiments of the present invention is significantly higher than that of the comparative examples, while the apparent porosity and average pore size are significantly lower than those of the comparative examples. This indicates that the carburization treatment, the second high-temperature heat treatment, and the silicon diffusion reaction sintering process adopted in the present invention can effectively optimize the internal pore structure of the material and improve the degree of densification. Specifically, the bulk density of Examples 1 to 3 increased from 3.12 g·cm⁻³ to 3.18 g·cm⁻³, the apparent porosity decreased from 0.3% to 0.2%, and the average pore size decreased from 0.08 μm to 0.04 μm, indicating that with the optimization of process parameters and proportions, the internal pores of the material are further reduced, and the structure becomes more compact. In contrast, Comparative Example 1, due to the absence of carburization treatment, and Comparative Example 2, due to the omission of the second high-temperature heat treatment, resulted in more residual pores and larger pore sizes inside the green body, leading to a significant decrease in bulk density. This result demonstrates that the process of the present invention is beneficial for promoting the full silicon diffusion reaction and reducing structural defects.

[0059] 3. Wear resistance test Each sample was processed into a disc-shaped specimen with a diameter of 12mm × 5mm. The friction surface was polished to Ra ≤ 0.2μm, followed by ultrasonic cleaning with anhydrous ethanol and drying. The wear resistance of each sample was evaluated using a ball-and-disc friction and wear test. Si3N4 ceramic balls (Φ6mm, hardness ≥ 32GPa) were used as the grinding pair. The test was conducted at room temperature under dry friction conditions: load 10N, rotation speed 200r / min, friction radius 5mm, and test time 30min. The friction coefficient curve was recorded in real time. After the test, the wear track volume was measured using a 3D profilometer with an accuracy of 0.01μm, and the wear rate was calculated based on the wear volume, load, and sliding distance. Three valid specimens (with no cracks on the friction surface and regular wear tracks) were tested for each group of samples, and the average value was taken as the final result. The results are shown in Table 3 below.

[0060] Table 3 Abrasion resistance test results

[0061] As shown in Table 3, the average friction coefficient and wear rate of the high-strength diamond-silicon carbide composite ceramic materials obtained in the embodiments of the present invention are significantly lower than those of the comparative samples, indicating that the process of the present invention can significantly improve the wear resistance of the material. Specifically, the average friction coefficient of Examples 1 to 3 decreased from 0.22 to 0.15, and the wear rate decreased from 1.8 × 10⁻⁹ mm³·N⁻¹·m⁻¹ to 0.75 × 10⁻⁹ mm³·N⁻¹·m⁻¹. This indicates that with the increase of diamond content and the synergistic optimization of carburization treatment, second high-temperature heat treatment, and silicon infiltration reaction sintering process, the surface hardness, structural density, and interfacial bonding strength of the material are further improved, thereby effectively reducing material spalling and abrasive wear during the friction process. In contrast, Comparative Example 1, due to the lack of carburization treatment, and Comparative Example 2, due to the lack of a second high-temperature heat treatment, both showed significantly increased friction coefficients and wear rates, indicating that the process of the present invention is beneficial for reducing surface defects and porosity, and enhancing wear resistance.

[0062] 4. Compressive strength test Each sample was processed into a 5 mm × 5 mm × 5 mm cube standard specimen, ensuring that the upper and lower pressure surfaces were parallel and perpendicular. The specimen surface was polished to Ra ≤ 0.2 μm and cleaned and dried before testing. The compressive strength was tested using an electronic universal testing machine according to GB / T 8489-2006. The specimen was placed in the center of the pressure plate and continuously loaded at a loading rate of 0.5 MPa / s at room temperature until the specimen failed. The maximum failure load was recorded and converted into compressive strength. Five valid specimens were tested for each group of samples, and the average value was taken. The results are shown in Table 4 below.

[0063] Table 4 Compressive strength test results

[0064] As shown in Table 4, the compressive strength of the high-strength diamond-silicon carbide composite ceramic materials obtained in the examples is significantly higher than that of the comparative samples, indicating that the carburization treatment, second high-temperature heat treatment, and silicon diffusion reaction sintering process adopted in this invention can effectively improve the compressive load-bearing capacity of the materials. Specifically, the compressive strength of Examples 1 to 3 increased from 1850 MPa to 2300 MPa, indicating that with the optimization of raw material ratio and process conditions, the internal structure of the material is more compact, the interfacial bonding between diamond and silicon carbide matrix is ​​stronger, and defects such as pores and microcracks are significantly reduced, thus enabling the material to more effectively transfer and withstand external loads during compression. In contrast, Comparative Example 1, due to the lack of carburization treatment, and Comparative Example 2, due to the lack of a second high-temperature heat treatment, both resulted in more residual pores and weaker interfacial bonding, thus significantly reducing their compressive strength.

[0065] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0066] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A method for preparing a high-strength diamond-silicon carbide composite ceramic material, characterized in that, Includes the following steps: S1. Mix silicon carbide powder and diamond powder in a certain proportion, add a binder, and obtain a composite powder with good flowability; S2. The composite powder is placed into a mold to form a ceramic blank; S3. Perform a first high-temperature degreasing treatment on the ceramic blank to remove the binder; S4. The degreased sample is subjected to carbonization treatment, wherein the carbonization treatment is performed by impregnation with a high residual carbon solution or chemical vapor permeation treatment; S5. Perform a second high-temperature degreasing treatment on the carbon-enriched ceramic green body to obtain a degreased green body. The degreasing temperature shall not exceed 1200℃. S6. The degreased green blank is subjected to silicon diffusion reaction sintering to obtain high-strength diamond silicon carbide composite ceramic material.

2. The preparation method according to claim 1, characterized in that, In step S1, the silicon carbide powder accounts for 30-90 wt% of the total mass of silicon carbide powder and diamond powder, and the diamond powder accounts for 10-70 wt% of the total mass of silicon carbide powder and diamond powder.

3. The preparation method according to claim 1, characterized in that, In step S1, the amount of binder added is 0.5 to 5 wt% of the total mass of silicon carbide powder and diamond powder, and the binder is selected from one or more of polyvinyl alcohol, polyvinyl butyral, polymethyl methacrylate, polyvinylpyrrolidone, and epoxy resin.

4. The preparation method according to claim 1, characterized in that, In step S2, the molding process is dry pressing and / or isostatic pressing; wherein the molding pressure of dry pressing is 15-100 MPa, and the molding pressure of isostatic pressing is 150-210 MPa.

5. The preparation method according to claim 1, characterized in that, The high residual carbon solution used in the carbonization treatment in step S4 is selected from one or more of phenolic resin, sucrose, and asphalt resin, and the carburizing medium used in the chemical vapor infiltration is a hydrocarbon gas.

6. The preparation method according to claim 1, characterized in that, The degreasing temperature is 900~1100℃, the degreasing time is 12~48 hours, and the porosity of the green blank after the second high-temperature heat treatment is 10~60%.

7. The preparation method according to claim 1, characterized in that, The temperature of the silicon diffusion reaction sintering in step S6 is 1450~1600℃, and the sintering time is 60~120 minutes.

8. A high-strength diamond-silicon carbide composite ceramic material, characterized in that, The material comprises a silicon carbide component and a diamond component, wherein the silicon carbide component accounts for 30 to 90 wt% of the total mass of the material, and the diamond component accounts for 10 to 70 wt% of the total mass of the material.

9. The high-strength diamond-silicon carbide composite ceramic material according to claim 8, characterized in that, The silicon carbide powder has a particle size of 10~300μm and a bulk density of 1.25~1.85 g / cm³; the diamond powder has a particle size of 10~250μm and a bulk density of 1.75~2.05 g / cm³.

10. The high-strength diamond-silicon carbide composite ceramic material according to claim 8, characterized in that, The mechanical properties of the high-strength diamond silicon carbide composite ceramic material are a bending strength of 320~560 MPa and a hardness of 32~46 GPa.

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