Silicon carbide ceramic slurry for photocuring 3D printing, silicon carbide ceramic and preparation method of silicon carbide ceramic slurry

Abstract

The invention provides silicon carbide ceramic slurry for photocuring 3D printing, silicon carbide ceramic and a preparation method of the silicon carbide ceramic, and relates to the technical field of 3D printing ceramic. According to the preparation method of the silicon carbide ceramic slurry for photocuring 3D printing, the SiC powder is wrapped with Y2O3-Al2O3, and the relative dosage of the yttrium oxide precursor, the aluminum oxide precursor and the SiC powder is controlled, so that the solid content, the curing depth and the curing efficiency are improved. The invention further provides a preparation method of the silicon carbide ceramic, the silicon carbide ceramic slurry with high solid content, high curing depth and high curing efficiency is adopted in the method, the silicon carbide slurry can better guarantee the integrity of the silicon carbide ceramic in the printing process, and deformation and cracking phenomena caused by sintering are reduced. Meanwhile, Y2O3 and Al2O3 can also be used as sintering aids of SiC, so that the density of sintered silicon carbide is improved, and the mechanical property of the silicon carbide ceramic is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printing ceramics, and in particular to a silicon carbide ceramic slurry for photocuring 3D printing, a silicon carbide ceramic and a preparation method thereof. Background Art

[0002] Silicon carbide ceramics have been widely used in high-end fields such as aerospace, chemical industry, machinery and integrated circuits due to their low density, good corrosion resistance, high temperature stability and good mechanical properties. Although traditional silicon carbide ceramic forming methods such as dry pressing, cold isostatic pressing, slip casting, tape casting, injection molding, etc. can produce silicon carbide ceramics of a certain quality and density, these methods show obvious limitations when manufacturing ceramic products with high precision and high complexity structures. In addition, these traditional processes are time-consuming and costly, which limits the large-scale production and application of silicon carbide ceramic materials.

[0003] In recent years, 3D printing technology has provided a new way for the preparation of ceramic materials with its flexible design and efficient material utilization. In particular, photocuring 3D printing technology, with its high precision, high speed and high complexity, has shown great potential in the field of ceramic material manufacturing. However, there are still many challenges in photocuring 3D printing of dark ceramic materials, especially silicon carbide ceramics. These include the mismatch between the refractive index of ceramic powder and photocurable resin, as well as the scattering and reflection of light in silicon carbide slurry, which leads to limited curing depth of silicon carbide slurry and low solid content of silicon carbide slurry, thus affecting the quality and performance of the final silicon carbide ceramic product. Therefore, there is an urgent need to develop a method that can effectively solve the problems of poor curing depth and low solid content of silicon carbide ceramic slurry, so as to improve the precision and quality of photocuring 3D printing of silicon carbide ceramics. Summary of the invention

[0004] The purpose of the present invention is to provide a silicon carbide ceramic slurry, SiC ceramic and a preparation method thereof for photocuring 3D printing. The preparation method of the silicon carbide ceramic slurry is simple in process and low in cost. The prepared silicon carbide ceramic slurry has good curing depth, high solid content and excellent printing and forming performance, laying a foundation for the subsequent preparation of high-performance silicon carbide ceramics.

[0005] The technical solution adopted by the present invention is as follows:

[0006] The present invention provides a method for preparing a silicon carbide ceramic slurry for photocuring 3D printing, comprising the following steps:

[0007] S1. SiC surface modification: uniformly mix a silane coupling agent and SiC powder in a toluene solution, wash and dry to obtain modified SiC powder; the mass ratio of the silane coupling agent, SiC powder and toluene is (0.01-0.1):1:(5-10);

[0008] S2, preparing sol: adding a gel accelerator to an aqueous solution containing a yttrium oxide precursor, an aluminum oxide precursor and ethanol, stirring evenly, adding the modified SiC powder described in step S1, and continuing to stir evenly to obtain a SiC precipitate wrapped with Y2(OH)3 and Al2(OH)3; the molar ratio of the ethanol, water, yttrium oxide precursor, aluminum oxide precursor and SiC powder is ethanol: water: yttrium oxide precursor: aluminum oxide precursor: SiC powder = (10-15): 1: (0.5-5): (0.2-1): (1-5);

[0009] S3, calcination: the Y2(OH)3 and Al2(OH)3 coated SiC precipitate in step S2 is dried and calcined to obtain Y2O3-Al2O3 coated SiC powder;

[0010] S4. Prepare photocurable slurry: add the Y2O3-Al2O3 coated SiC powder prepared in step S3 to a mixed solution containing a photosensitive resin, a photoinitiator and a dispersant to obtain Y2O3-Al2O3 coated SiC photocurable slurry.

[0011] The method for preparing silicon carbide ceramic slurry for photocuring 3D printing provided by the present invention uses Y2O3-Al2O3 to wrap SiC powder, and controls the relative amounts of yttria precursor, alumina precursor and SiC powder to match the refractive index of silicon carbide ceramic powder with that of photocuring resin, thereby avoiding scattering and reflection of light in silicon carbide ceramic slurry. The prepared photocuring 3D printing slurry has excellent curing depth when the solid content is the same as that of the traditional method (such as particle grading or oxidation treatment), which significantly improves the curing efficiency of the slurry. In addition, the method for preparing ceramic slurry for photocuring printing provided by the present invention can further increase the solid content of SiC ceramic slurry wrapped with Y2O3-Al2O3. Compared with the traditional method, the solid content of the slurry can be increased by about 5vol%.

[0012] In a possible implementation, the alkane coupling agent in step S1 is at least one of KH550, KH560, KH570 and KH792.

[0013] In a possible implementation manner, the particle size of the SiC in step S1 is 1 to 50 μm.

[0014] In a possible implementation, in step S2, the yttrium oxide precursor is YCl3·6H2O, the aluminum oxide precursor is AlCl3·6H2O; and the gel accelerator is propylene oxide.

[0015] In a possible implementation manner, the calcination atmosphere in step S3 is N2, and the calcination equipment is a tubular furnace.

[0016] In a possible implementation manner, the calcination temperature in step S3 is 400-600° C., and the calcination time is 1-3 hours.

[0017] In a possible implementation, the photosensitive resin in step S4 is at least one of polyurethane acrylate, n-butyl acrylate, acrylic acid, pentaerythritol triacrylate, trihydroxypropane triacrylate, hexanediol diacrylate and acryloylmorpholine.

[0018] In a possible implementation, the photoinitiator in step S4 is any one of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphonate, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide and 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinobenzylphenyl)butanone.

[0019] In a possible implementation manner, the model of the dispersant in step S4 is at least one of KOS110, KOS2000 and BYK410.

[0020] The amount of photosensitive resin used is 20-35wt.% of the total amount of the photosensitive resin and the Y2O3-Al2O3 wrapped SiC powder; the amount of the photoinitiator used is 2-5wt.% of the total amount of the photosensitive resin and the photoinitiator; the amount of the dispersant used is 2-5wt.% of the total amount of the Y2O3-Al2O3 wrapped SiC powder and the dispersant; the amount of the Y2O3-Al2O3 wrapped SiC powder added is 40-50vol% of the total volume of the mixed solution and the Y2O3-Al2O3 wrapped SiC powder.

[0021] The present invention also provides silicon carbide ceramic slurry prepared by the method for preparing the silicon carbide ceramic slurry.

[0022] The present invention also provides a method for preparing silicon carbide ceramics using the above silicon carbide ceramic slurry, which comprises the following steps:

[0023] F1. Printing a blank: adding the Y2O3-Al2O3 coated SiC photocuring slurry into a 3D printing device and printing it into a blank;

[0024] F2, curing: the green body obtained in step F1 is cured to obtain a cured green body;

[0025] F3, degreasing: the solidified body obtained in step F2 is degreased by a three-stage heating and three-stage heat preservation method, and then cooled to room temperature to obtain a silicon carbide ceramic body;

[0026] SF4, sintering: the silicon carbide ceramic body prepared in step F3 is sintered at 1800-2100° C. to obtain dense silicon carbide ceramics.

[0027] The high solid content slurry prepared can better ensure the integrity of the sample during the printing process and reduce the deformation and cracking caused by sintering. At the same time, Y2O3 and Al2O3 can also be used as sintering aids for SiC to increase the density of the sintered sample and thus improve the mechanical properties of the product.

[0028] In a possible implementation, in step F2, the curing process is sequentially curing at 50° C., 100° C., 150° C., and 200° C., and the total curing time is 0.5 to 3 hours;

[0029] In a possible implementation manner, in step F3, the degreasing process is as follows: the solidified body is placed in a tube furnace, nitrogen is introduced, the temperature is increased from room temperature to 200-300°C at a heating rate of 0.5-2°C / min, the temperature is kept at that temperature for 1-2h, the temperature is further increased to 400-600°C at a heating rate of 0.5-2°C / min, the temperature is kept at that temperature for 2-4h, and then the temperature is further increased at a heating rate of 1-4°C / min.

[0030] / min heating rate to 800-1000℃ and keep warm for 1-2h.

[0031] In a possible implementation, the sintering temperature in step F4 is first increased to 800-1000°C at a heating rate of 1-5°C / min, then increased to 1400-1600°C at a heating rate of 5-10°C / min, and then increased to 1800-2100°C at a heating rate of 1-5°C / min.

[0032] In a possible implementation manner, the sintering equipment in step F4 is a vacuum furnace.

[0033] The present invention also provides silicon carbide ceramics prepared by the method for preparing silicon carbide ceramics.

[0034] The reagents and raw materials used in the present invention are commercially available.

[0035] The positive and progressive effects of the present invention are:

[0036] The method for preparing silicon carbide ceramic slurry for photocuring 3D printing provided by the invention has a simple process and low cost. Compared with the traditional methods (such as particle grading or oxidation treatment) of the prepared ceramic slurry for photocuring printing, when the solid content is the same, the Y2O3-Al2O3-coated SiC ceramic slurry has an excellent curing depth, which significantly improves the curing efficiency of the slurry. In addition, the method for preparing ceramic slurry for photocuring printing described in the present invention can further increase the solid content of the Y2O3-Al2O3-coated SiC ceramic slurry. Compared with the traditional method, the solid content of the slurry can be increased by about 5 vol%.

[0037] When the silicon carbide ceramic slurry provided by the present invention is used for 3D printing of silicon carbide ceramics, the high solid content silicon carbide ceramic slurry can better ensure the integrity of the sample during the printing process and reduce the deformation and cracking caused by sintering. At the same time, Y2O3 and Al2O3 can also be used as sintering aids for SiC to improve the density of the sintered silicon carbide ceramic sample, thereby improving the mechanical properties of the silicon carbide ceramic product. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a scanning electron microscope (SEM) image of the Y2O3-Al2O3 coated SiC powder prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0039] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below. It should be noted that the following embodiments are only used to illustrate the implementation method and typical parameters of the present invention, and are not used to limit the parameter range described in the present invention. Reasonable changes derived therefrom are still within the scope of protection of the claims of the present invention.

[0040] It should be noted that the endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed in this article.

[0041] Unless otherwise defined, all terms, symbols and other scientific terms used herein are intended to have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. In some cases, terms with conventionally understood meanings are defined herein for the purpose of clarification or ease of reference, and such definitions herein should not be construed as indicating significant differences from conventional understandings 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 is carried out in accordance with the protocols and parameters given by the manufacturer.

[0042] Example 1

[0043] This embodiment provides a silicon carbide ceramic slurry for photocuring 3D printing, which is prepared by the following preparation method:

[0044] (1) SiC surface modification: silane coupling agent and SiC powder are added to a toluene solution and mixed evenly, and modified SiC powder is obtained by washing and drying. The mass ratio of silane coupling agent, SiC powder and toluene is 0.1:1:5;

[0045] (2) Preparation of sol: ethanol and water are mixed evenly, YCl3·6H2O and AlCl3·6H2O are added respectively and the mixture is stirred, then propylene oxide solvent is added and stirred continuously, and modified SiC powder is added and stirred continuously to obtain a stable Y2(OH)3 and Al2(OH)3-encapsulated SiC precipitate; according to the molar ratio, ethanol: water: YCl3·6H2O: AlCl3·6H2O: SiC powder = 10:1:0.5:0.3:1, and the particle size of SiC powder ranges from 10 μm to 30 μm;

[0046] (3) Calcination: The above solution is completely evaporated, dried in an oven, and then the sample is transferred into a tube furnace and calcined at 400°C for 1 h in a N2 atmosphere to obtain Y2O3-Al2O3 coated SiC powder;

[0047] (4) Preparing silicon carbide photocuring slurry: polyurethane acrylate, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and a dispersant of model KOS110 are mixed evenly, and then the Y2O3-Al2O3 coated SiC powder in step (3) is added and stirred continuously to obtain a photocuring slurry of Y2O3-Al2O3 coated SiC powder. The mass ratio is polyurethane acrylate: 2,4,6-trimethylbenzoyl-diphenylphosphine oxide: KOS110: Y2O3-Al2O3 coated SiC powder

[0048] =20:2:4:80.

[0049] Figure 1This is a scanning electron microscope (SEM) image of the Y2O3-Al2O3 coated SiC powder prepared in this example. As can be seen from the image, there are small particles on the surface of the Y2O3-Al2O3 coated SiC powder, indicating that Y2O3 and Al2O3 have a coating effect on the SiC powder.

[0050] Example 2

[0051] This embodiment provides a silicon carbide ceramic slurry for photocuring 3D printing, which is prepared by the following preparation method:

[0052] (1) SiC surface modification: silane coupling agent and SiC powder are added to a toluene solution and mixed evenly, and modified SiC powder is obtained by washing and drying. The mass ratio of silane coupling agent, SiC powder and toluene is 0.01:1:10;

[0053] (2) preparing sol: ethanol and water are mixed evenly, YCl3·6H2O and AlCl3·6H2O are added respectively and the mixture is stirred, then propylene oxide solvent is added and the mixture is stirred continuously, and modified SiC powder is added and the mixture is stirred continuously to obtain a stable SiC precipitate wrapped with Y2(OH)3 and Al2(OH)3; according to the molar ratio, ethanol: water: YCl3·6H2O: AlCl3·6H2O: SiC powder = 15:1:0.2:0.2:1, and the particle size of SiC powder ranges from 1 μm to 50 μm;

[0054] (3) Calcination: The above solution is completely evaporated, dried in an oven, and then the sample is transferred into a tube furnace and calcined at 400°C for 1 h in a N2 atmosphere to obtain Y2O3-Al2O3 coated SiC powder;

[0055] (4) Preparing silicon carbide photocuring slurry: pentaerythritol triacrylate, phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, and a dispersant of model KOS110 are mixed evenly, and then the Y2O3-Al2O3 coated SiC powder in step (3) is added and stirred continuously to obtain a photocuring slurry of Y2O3-Al2O3 coated SiC powder. The mass ratio of pentaerythritol triacrylate: phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide: KOS110: Y2O3-Al2O3 coated SiC powder is 35:2:2:65).

[0056] Example 3

[0057] This embodiment provides a silicon carbide ceramic, which is prepared by the following preparation method:

[0058] D1. Preparation of silicon carbide blank: adding the silicon carbide ceramic slurry prepared in Example 1 into a 3D printing device to print into a blank;

[0059] D2. Curing: Place the blank in an oven for thermal curing, curing at 50°C for 0.5h, 100°C for 0.5h, 150°C for 0.5h, and 200°C for 1h in sequence;

[0060] D3, degreasing: the solidified body is placed in a tubular furnace, and the temperature is raised from room temperature to 200°C at a heating rate of 0.5°C / min through nitrogen, and kept at this temperature for 1 hour, and then the temperature is raised to 400°C at a heating rate of 0.5°C / min, and kept at this temperature for 2 hours, and then the temperature is raised to 800°C at a heating rate of 1°C / min, and kept at this temperature for 1 hour, and then cooled to room temperature to obtain a Y2O3-Al2O3-coated SiC body;

[0061] D4. Densification sintering: Place the green body in a vacuum furnace and heat it to 800°C at a heating rate of 1°C / min, then heat it to 1400°C at a heating rate of 5°C / min, and then heat it to 1800°C at a heating rate of 1°C / min. A dense SiC ceramic sample is obtained.

[0062] The more Y2O3 and Al2O3 are coated on the surface of SiC powder, the greater the curing depth is. The curing depth of the silicon carbide ceramic prepared in Example 3 can reach 220 μm.

[0063] The more Y2O3 and Al2O3 are coated on the surface of SiC powder, the higher the density and bending strength of the prepared silicon carbide ceramics. The density of the silicon carbide ceramics prepared in Example 3 can reach 99%, the bending strength can reach 350MPa, and the fracture toughness can reach 4MPa·m 1 / 2 .

[0064] Example 4

[0065] This embodiment provides a silicon carbide ceramic, which is prepared by the following preparation method:

[0066] D1. Preparation of silicon carbide blank: adding the silicon carbide ceramic slurry prepared in Example 2 into a 3D printing device to print into a blank;

[0067] D2. Curing: Place the blank in an oven for thermal curing, curing at 50°C for 0.5h, 100°C for 1h, 150°C for 0.5h, and 200°C for 1h in sequence;

[0068] D3, degreasing: the solidified body is placed in a tubular furnace, and the temperature is raised from room temperature to 300°C at a heating rate of 2°C / min through nitrogen, and kept at this temperature for 2 hours, and then the temperature is raised to 600°C at a heating rate of 2°C / min, and kept at this temperature for 4 hours, and then the temperature is raised to 1000°C at a heating rate of 4°C / min, and kept at this temperature for 2 hours, and then cooled to room temperature to obtain a Y2O3-Al2O3-coated SiC body;

[0069] D4. Densification sintering: Place the green body in a vacuum furnace and heat it to 1000°C at a heating rate of 5°C / min, then heat it to 1600°C at a heating rate of 10°C / min, and then heat it to 2100°C at a heating rate of 5°C / min. A dense SiC ceramic sample is obtained.

[0070] Comparative Example 1

[0071] Comparative Example 1 provides a silicon carbide ceramic slurry. The difference between Comparative Example 1 and Example 1 is that in step (1), ethanol: water: YCl3·6H2O: AlCl3·6H2O: SiC powder = 10:3:6:2:8.

[0072] The solid content of the silicon carbide ceramic slurry in Comparative Example 1 is 68 wt %.

[0073] Comparative Example 2

[0074] Comparative Example 2 provides a silicon carbide ceramic. The difference between Comparative Example 2 and Example 3 is that the silicon carbide ceramic slurry prepared in Comparative Example 1 is used in step D1.

[0075] The solidification depth of the silicon carbide ceramic prepared in Comparative Example 2 is 165 μm.

[0076] 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 it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, 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 method for preparing silicon carbide ceramic slurry for photocuring 3D printing, It is characterized in that The following steps are involved: S1. SiC surface modification: uniformly mix a silane coupling agent and SiC powder in a toluene solution, wash and dry to obtain modified SiC powder; the mass ratio of the silane coupling agent, SiC powder and toluene is (0.01-0.1):1:(5-10); S2, preparing sol: adding a gel accelerator to an aqueous solution containing a yttrium oxide precursor, an aluminum oxide precursor and ethanol, stirring evenly, adding the modified SiC powder described in step S1, and continuing to stir to obtain Y 2 (OH) 3 and Al 2 (OH) 3 Encapsulating SiC precipitate; the molar ratio of ethanol, water, yttrium oxide precursor, aluminum oxide precursor and SiC powder is ethanol: water: yttrium oxide precursor: aluminum oxide precursor: SiC powder = (10-15): 1: (0.2-5): (0.2-1): (1-5); S3, calcination: Y 2 (OH) 3 and Al 2 (OH) 3 The SiC precipitate was aged, filtered, washed, dried and calcined to obtain Y 2 O 3 -Al 2 O 3 Encapsulating SiC powder; S4, prepare light-curing slurry: add Y prepared in step S3 to the mixed solution containing photosensitive resin, photoinitiator and dispersant. 2 O 3 -Al 2 O 3 Wrap SiC powder to obtain Y 2 O 3 -Al 2 O 3 Encapsulate SiC photocuring paste.

2. The method for preparing the silicon carbide ceramic slurry according to claim 1, It is characterized in that In step S1, the silane coupling agent is at least one of KH550, KH560, KH570 and KH792; and the particle size of the SiC is 1 to 50 μm.

3. The method for preparing the silicon carbide ceramic slurry according to claim 1, It is characterized in that In step S2, the yttrium oxide precursor is YCl 3 6H 2 O, the aluminum oxide precursor is AlCl 3 6H 2 O; the gel accelerator is propylene oxide.

4. The method for preparing the silicon carbide ceramic slurry according to claim 1, It is characterized in that In step S3, the calcination temperature is 400-600°C, and the calcination atmosphere is N 2 The calcination time is 1 to 3 hours.

5. The method for preparing the silicon carbide ceramic slurry according to claim 1, It is characterized in that In step S4, the photosensitive resin is at least one of polyurethane acrylate, n-butyl acrylate, acrylic acid, pentaerythritol triacrylate, trihydroxypropane triacrylate, hexanediol diacrylate and acryloyl morpholine; And / or, the photoinitiator is any one of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphonate, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide and 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinobenzylphenyl)butanone; And / or, the dispersant is of at least one type selected from KOS110, KOS2000 and BYK410.

6. The method for preparing the silicon carbide ceramic slurry according to claim 1, It is characterized in that In step S4, the amount of the photosensitive resin is 2 O 3 -Al 2 O 3 The amount of the encapsulated SiC powder is 20 to 35 wt.%; the amount of the photoinitiator is 2 to 5 wt.% of the total amount of the photosensitive resin and the photoinitiator; the amount of the dispersant is 2 O 3 -Al 2 O 3 2 to 5 wt% of the total amount of the SiC powder and the dispersant; the Y 2 O 3 -Al 2 O 3 The amount of SiC powder added is the mixed solution and the Y 2 O 3 -Al 2 O 3 40-50 vol% of the total volume of the encapsulated SiC powder.

7. A silicon carbide ceramic slurry, It is characterized in that The silicon carbide ceramic slurry is prepared by the method for preparing the silicon carbide ceramic slurry according to any one of claims 1 to 5.

8. A method for preparing silicon carbide ceramics using the silicon carbide ceramic slurry according to claim 7, It is characterized in that The following steps are involved: F1. Printing a green body: adding the silicon carbide ceramic slurry into a 3D printing device and printing it into a green body; F2, curing: the green body obtained in step F1 is cured to obtain a cured green body; F3, degreasing: the solidified body obtained in step F2 is degreased and then cooled to room temperature to obtain a silicon carbide ceramic body; F4. Sintering: The silicon carbide ceramic body prepared in step F3 is sintered at 1800-2100° C. to obtain silicon carbide ceramics.

9. The method for preparing silicon carbide ceramics according to claim 8, It is characterized in that In step F2, the curing process is sequentially curing at 50°C, 100°C, 150°C, and 200°C, and the total curing time is 0.5 to 3 hours; And / or, in step F3, the degreasing process is as follows: the solidified body is placed in a tubular furnace, nitrogen is introduced, the temperature is increased from room temperature to 200-300° C. at a heating rate of 0.5-2° C. / min, the temperature is kept at that temperature for 1-2 hours, the temperature is further increased to 400-600° C. at a heating rate of 0.5-2° C. / min, the temperature is kept at that temperature for 2-4 hours, and the temperature is then increased to 800-1000° C. at a heating rate of 1-4° C. / min, the temperature is kept at that temperature for 1-2 hours; And / or, in step F4, the sintering temperature is first increased to 800-1000°C at a heating rate of 1-5°C / min, then increased to 1400-1600°C at a heating rate of 5-10°C / min, and then increased to 1800-2100°C at a heating rate of 1-5°C / min.

10. A silicon carbide ceramic, It is characterized in that The silicon carbide ceramic is prepared by the method for preparing the silicon carbide ceramic according to any one of claims 8 to 9.

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