Preparation method of high-purity silicon carbide ceramic powder with controllable particle size

Abstract

The invention belongs to the field of ceramic materials, and particularly relates to a preparation method of high-purity silicon carbide ceramic powder with a controllable particle size. The preparation method of the high-purity silicon carbide ceramic powder with the controllable particle size comprises the following steps: (1) ball-milling and mixing carbon black powder, a binder, a dispersing agent, a pore-forming agent and a solvent to obtain carbon powder slurry, and performing spray granulation to obtain carbon black granulated powder; (2) mixing carbon black granulation powder obtained by spray granulation with silicon powder, and sintering at high temperature; carbon black powder is used as a raw material, a binder, a dispersing agent and a pore forming agent are combined, carbon black granulation powder with controllable particle size is obtained through spray granulation, then the carbon black granulation powder is mixed with silicon powder for high-temperature sintering to serve as a reaction template, finally, high-purity silicon carbide ceramic powder with controllable particle size is obtained, and the obtained silicon carbide ceramic powder is applied to a selective laser sintering technology.

Description

Technical Field

[0001] The invention belongs to the field of ceramic materials, and in particular relates to a method for preparing high-purity silicon carbide ceramic powder with controllable particle size. Background Art

[0002] Silicon carbide ceramics are widely used in aerospace, electronic semiconductors, energy and environmental protection due to their high hardness, high strength, excellent wear resistance and thermal properties. Their high thermal conductivity and low thermal expansion coefficient make them suitable for high-temperature structural components and high-frequency electronic devices, while their excellent corrosion resistance and lightweight properties meet the needs of chemical equipment and protective armor. In addition, silicon carbide ceramics are also used in high-end technical fields such as filtering, sealing and optical substrates due to their adjustable electrical properties and high-temperature stability. They are advanced ceramic materials with great potential.

[0003] Silicon carbide ceramics prepared by selective laser sintering (SLS) technology have the advantages of complex structure, high material utilization rate and mold-free production. They can realize geometric shapes that are difficult to process by traditional processes, while reducing material waste and production costs. This technology can meet the needs of small batches, high precision and customization while maintaining the high hardness, wear resistance, corrosion resistance and high temperature stability of silicon carbide. It is widely used in aerospace, energy, electronic semiconductors and other fields, and is an important innovative technology for high-performance ceramic manufacturing. The requirements for silicon carbide powder in the preparation of silicon carbide ceramics by SLS are very strict, mainly including high purity, narrow particle size distribution and good fluidity, in order to adapt to the process requirements of stacking powder, ensure the uniformity of the printing process and the high density and stable performance of the ceramics after sintering, so as to meet the requirements of complex structure manufacturing and high-performance applications. Therefore, the preparation of a high-purity silicon carbide powder with controllable particle size and large particle size (need to balance powder fluidity and sintering activity) is very critical for the development of SLS preparation of silicon carbide ceramics. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing high-purity silicon carbide ceramic powder with controllable particle size in response to the above technical problems. Carbon black powder is used as a raw material, combined with a binder, a dispersant and a pore-forming agent, and carbon black granulated powder with controllable particle size is obtained by spray granulation, which is then mixed with silicon powder to finally obtain high-purity silicon carbide ceramic powder with controllable particle size.

[0005] The method for preparing high-purity silicon carbide ceramic powder with controllable particle size in the technical solution of the present invention comprises the following steps:

[0006] (1) mixing carbon black powder, a binder, a dispersant, a pore-forming agent and a solvent by ball milling to obtain a carbon powder slurry, and obtaining carbon black granulated powder by spray granulation;

[0007] (2) The carbon black granulated powder obtained by spray granulation is mixed with silicon powder and then sintered at high temperature.

[0008] During the reaction of carbon black granulated powder and silicon powder, the carbon black granulated powder with controllable particle size acts as a template, and the silicon carbide ceramic powder generated after the reaction is complete will not change significantly in size, thereby obtaining high-purity silicon carbide ceramic powder with controllable particle size.

[0009] Furthermore, the particle size of the carbon black powder in step (1) is less than 1.5 μm, preferably 0.1 to 1.0 μm; a particle size that is too large is not conducive to the control of the powder morphology and particle size by subsequent spray granulation.

[0010] Furthermore, the binder in step (1) is a thermosetting resin, including but not limited to any one of phenolic resin, furan resin, and epoxy resin. Thermosetting resin can act as a binder in the spray granulation process to bind the carbon black powder for shaping, and a carbon skeleton with high hardness can be obtained in the high temperature process, so that the obtained carbon black granulated powder can continue to maintain its morphology, thereby acting as a template when reacting with molten silicon at high temperature.

[0011] Furthermore, the viscosity of the thermosetting resin is 3000 to 8000 mPa·s.

[0012] Furthermore, the dispersant in step (1) is an organic dispersant, including but not limited to one or more of polyethylene glycol, castor oil, polyacrylamide, fish oil, and cellulose derivatives.

[0013] Furthermore, the pore-forming agent in step (1) is a compound that can generate gas upon high-temperature decomposition, including but not limited to one or more of ammonium carbonate, ammonium bicarbonate, ammonium chloride, and oxalic acid; the gas generated by the pore-forming agent during the high-temperature sintering process can cause continuous pores to be generated inside the carbon black granulated powder, and the molten silicon droplets can utilize the continuous pores inside to effectively penetrate into the carbon black granulated powder through capillary force and fully react with the carbon black granulated powder, thereby generating a uniform pure phase silicon carbide ceramic powder.

[0014] Preferably, the solvent in step (1) is any one of ethanol, acetone, dimethyl sulfoxide, and N,N-dimethylformamide.

[0015] Furthermore, in step (1), the masses of the binder, dispersant and pore-forming agent are 1-30wt%, 0.5-3.0wt% and 0.1-1.0wt% of the mass of the carbon black powder, respectively.

[0016] Furthermore, in step (1), the mass of the solvent is 1 to 10 times the sum of the mass of the carbon black powder, the binder, the dispersant and the pore-forming agent.

[0017] Furthermore, in step (1), the rotation speed of the ball milling mixing is 100 to 500 rpm, and the time is 1 to 12 hours.

[0018] Furthermore, during the spray granulation in step (1), the slurry feed rate is 5-120 rpm, the centrifugal disk speed is 1000-30000 rpm, the air inlet temperature is 80-200°C, and the air outlet temperature is 50-100°C.

[0019] Preferably, the spray granulation is carried out in a nitrogen environment by a spray granulation drying device.

[0020] Furthermore, in step (2), the molar ratio of carbon black granulated powder to silicon powder is 1.0-1.5:1.0, preferably 1.0-1.1:1.0.

[0021] Furthermore, in step (2), the median particle size of the silicon powder is 1 to 5 μm.

[0022] Furthermore, in step (2), the high temperature sintering is first carried out at 1100-1350° C. for 1-12 hours, and then the temperature is raised to 1500-1900° C. for 2-20 hours.

[0023] Preferably, the high temperature sintering is carried out in a high purity argon environment with a vacuum degree of less than 10 -3 Pa.

[0024] Furthermore, the silicon carbide ceramic powder obtained after high-temperature sintering is subjected to decarbonization treatment and shaping treatment in sequence; the decarbonization treatment is carried out by sintering at 500-900°C for 0.5-3.0h in an air environment; and the shaping treatment is achieved by mechanical grinding for 0.5-12h.

[0025] The present invention also provides a high-purity silicon carbide ceramic powder with controllable particle size, which is prepared by the above-mentioned method for preparing the high-purity silicon carbide ceramic powder with controllable particle size.

[0026] Furthermore, the silicon carbide ceramic powder is applied to the selective laser sintering technology.

[0027] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0028] (1) The present invention uses carbon black powder as a raw material, combines a binder, a dispersant and a pore-forming agent, obtains carbon black granulated powder with controllable particle size by spray granulation, and then mixes it with silicon powder for high-temperature sintering to act as a reaction template, and finally obtains high-purity silicon carbide ceramic powder with controllable particle size;

[0029] (2) Thermosetting resin is used as a binder to bind the carbon black powder for shaping, and a carbon skeleton with high hardness can be obtained during the high temperature process, so that the carbon black granulated powder obtained by spray granulation can continue to maintain its morphology and act as a template when reacting with molten silicon at high temperature;

[0030] (3) The gas generated by the decomposition of the pore-forming agent during the high-temperature sintering process can generate continuous pores inside the carbon black granulated powder, so that the molten silicon droplets can utilize the continuous pores inside and, through capillary force, effectively penetrate into the carbon black granulated powder and fully react with the carbon black granulated powder, thereby generating a uniform pure phase silicon carbide ceramic powder;

[0031] (4) After high-temperature sintering, carbon removal and shaping treatment are performed to make the obtained silicon carbide ceramic powder have higher purity and more complete appearance structure;

[0032] (5) The obtained high-purity silicon carbide ceramic powder with controllable particle size is applied to selective laser sintering technology, which can ensure the uniformity of the printing process and the high density and stable performance of the sintered ceramics, meeting the requirements of complex structure manufacturing and high-performance applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a SEM image of the silicon carbide ceramic powder obtained in Example 1;

[0034] Figure 2 This is the XRD pattern of the silicon carbide ceramic powder obtained in Example 1. DETAILED DESCRIPTION

[0035] The technical scheme of the present invention is further described below by specific examples and accompanying drawings. It should be understood that the specific examples described herein are only used to help understand the present invention and are not intended for specific limitations of the present invention. The accompanying drawings used herein are only for better illustrating the disclosed content of the present invention and do not have a limiting effect on the scope of protection. If not otherwise specified, the raw materials used in the embodiments of the present invention are all commonly used raw materials in the art, and the methods used in the embodiments are all conventional methods in the art.

[0036] The silicon powder in the following examples and comparative examples was purchased from Xiamen Jintung New Materials Co., Ltd., and the carbon black powder was purchased from Tianjin Tianyi Century Chemical Products Technology Development Co., Ltd.

[0037] Example 1

[0038] The method for preparing silicon carbide ceramic powder in this embodiment comprises the following steps:

[0039] (1) 10 parts of carbon black powder (particle size of 0.1 μm), 1.0 part of phenolic resin (viscosity of 5000 mPa·s), 0.05 parts of polyethylene glycol and 0.01 parts of ammonium carbonate were placed in a ball mill, 35 parts of ethanol were added, and the mixture was ball milled and mixed at 300 rpm for 2 h to obtain a carbon powder slurry, which was then spray granulated by a spray granulation drying device under a nitrogen atmosphere, with a slurry feeding speed of 50 rpm, a centrifugal disk speed of 10000 rpm, an air inlet temperature of 130° C., and an air outlet temperature of 70° C.;

[0040] (2) The carbon black granulated powder obtained by spray granulation was mixed with silicon powder in a molar ratio of 1.03:1.0. The obtained powder was placed in a crucible and placed in a sintering furnace. The vacuum degree of the sintering furnace was 5×10 -4 Pa, then high-purity argon is introduced to normal pressure, the air in the sintering furnace is removed by three cycles, the temperature is raised to 1350°C and maintained for 3 hours, the temperature is then raised to 1650°C and maintained for 3 hours, and the silicon carbide ceramic powder is obtained by cooling to room temperature;

[0041] (3) The obtained silicon carbide ceramic powder was heat treated at 600°C in air for 1.0 h to remove excess carbon, and then ground for 3 h to obtain silicon carbide ceramic powder with a median particle size of 10.6 μm, such as Figure 1 As shown; the obtained is a pure phase silicon carbide ceramic powder, which does not contain other phase components, such as Figure 2 shown.

[0042] Example 2

[0043] The method for preparing silicon carbide ceramic powder in this embodiment comprises the following steps:

[0044] (1) 10 parts of carbon black powder (particle size of 0.5 μm), 1.0 part of phenolic resin (viscosity of 6000 mPa·s), 0.1 part of polyethylene glycol and 0.01 part of ammonium chloride were put into a ball mill, 35 parts of ethanol were added, and the mixture was ball milled and mixed at 300 rpm for 2 h to obtain a carbon powder slurry, which was then spray granulated by a spray granulation drying device under a nitrogen atmosphere, with a slurry feeding speed of 60 rpm, a centrifugal disk speed of 8000 rpm, an air inlet temperature of 140° C., and an air outlet temperature of 75° C.;

[0045] (2) The carbon black granulated powder obtained by spray granulation was mixed with silicon powder in a molar ratio of 1.05:1.0. The obtained powder was placed in a crucible and placed in a sintering furnace. The vacuum degree of the sintering furnace was 5×10 -4 Pa, and then introduce high-purity argon gas to normal pressure, cycle three times to remove the air in the sintering furnace, heat to 1300°C and hold for 4 hours, then heat to 1700°C and hold for 5 hours, and cool to room temperature to obtain silicon carbide ceramic powder;

[0046] (3) The obtained silicon carbide ceramic powder was heat treated in air at 700° C. for 1.5 h to remove excess carbon, and then ground for 4 h to obtain silicon carbide ceramic powder with a median particle size of 72.1 μm.

[0047] Example 3

[0048] The method for preparing silicon carbide ceramic powder in this embodiment comprises the following steps:

[0049] (1) 10 parts of carbon black powder (particle size of 1.0 μm), 2.0 parts of epoxy resin (viscosity of 5000 mPa·s), 0.05 parts of polyethylene glycol and 0.01 parts of ammonium carbonate were put into a ball mill, 35 parts of ethanol were added, and the mixture was ball milled and mixed at 300 rpm for 2 h to obtain a carbon powder slurry, which was then spray granulated by a spray granulation drying device under a nitrogen atmosphere, with a slurry feeding speed of 80 rpm, a centrifugal disk speed of 8000 rpm, an air inlet temperature of 140° C., and an air outlet temperature of 80° C.;

[0050] (2) The carbon black granulated powder obtained by spray granulation was mixed with silicon powder in a molar ratio of 1.01:1.0. The obtained powder was placed in a crucible and placed in a sintering furnace. The vacuum degree of the sintering furnace was 5×10 -4 Pa, and then introduce high-purity argon gas to normal pressure, cycle three times to remove the air in the sintering furnace, heat to 1250°C and hold for 3 hours, then heat to 1700°C and hold for 6 hours, and cool to room temperature to obtain silicon carbide ceramic powder;

[0051] (3) The obtained silicon carbide ceramic powder was heat treated in air at 800° C. for 1.5 h to remove excess carbon, and then ground for 3 h to obtain silicon carbide ceramic powder with a median particle size of 107.4 μm.

[0052] Example 4

[0053] The difference between this embodiment and embodiment 1 is that in step (1), 10 parts of carbon black powder (particle size of 0.1 μm), 1.0 part of phenolic resin (viscosity of 5000 mPa·s), 0.05 parts of polyethylene glycol and 0.04 parts of ammonium carbonate are put into a ball mill, 35 parts of ethanol are added, and the mixture is ball-milled and mixed at 300 rpm for 2 h to obtain a carbon powder slurry, which is then spray-granulated by a spray granulation drying equipment under a nitrogen atmosphere, with a slurry feed rate of 50 rpm, a centrifugal disk speed of 10000 rpm, an air inlet temperature of 130°C, and an air outlet temperature of 70°C; and finally, a silicon carbide ceramic powder with a median particle size of 9.9 μm is obtained.

[0054] Example 5

[0055] The difference between this embodiment and embodiment 1 is that in step (1), 10 parts of carbon black powder (particle size 0.1 μm), 1.0 part of phenolic resin (viscosity 5000 mPa·s), 0.05 parts of polyethylene glycol and 0.08 parts of ammonium carbonate are put into a ball mill, 35 parts of ethanol are added, and the mixture is ball-milled and mixed at 300 rpm for 2 h to obtain a carbon powder slurry, which is then spray-granulated by a spray granulation drying equipment under a nitrogen atmosphere, with a slurry feed rate of 50 rpm, a centrifugal disk speed of 10000 rpm, an air inlet temperature of 130°C, and an air outlet temperature of 70°C; and finally, a silicon carbide ceramic powder with a median particle size of 8.7 μm is obtained.

[0056] Example 6

[0057] The difference between this embodiment and embodiment 1 is that in step (1), 10 parts of carbon black powder (particle size 0.1 μm), 1.0 part of phenolic resin (viscosity 5000 mPa·s), 0.05 parts of polyethylene glycol and 0.12 parts of ammonium carbonate are put into a ball mill, 35 parts of ethanol are added, and the mixture is ball-milled and mixed at 300 rpm for 2 h to obtain a carbon powder slurry, which is then spray-granulated by a spray granulation drying equipment under a nitrogen atmosphere, with a slurry feed rate of 50 rpm, a centrifugal disk speed of 10000 rpm, an air inlet temperature of 130°C, and an air outlet temperature of 70°C; and finally, a silicon carbide ceramic powder with a median particle size of 7.2 μm is obtained.

[0058] Example 7

[0059] The method for preparing silicon carbide ceramic powder in this embodiment comprises the following steps:

[0060] (1) 10 parts of carbon black powder (particle size of 0.1 μm), 1.0 part of phenolic resin (viscosity of 5000 mPa·s), 0.05 parts of polyethylene glycol and 0.01 parts of ammonium carbonate were placed in a ball mill, 35 parts of ethanol were added, and the mixture was ball milled and mixed at 300 rpm for 2 h to obtain a carbon powder slurry, which was then spray granulated by a spray granulation drying device under a nitrogen atmosphere, with a slurry feeding speed of 50 rpm, a centrifugal disk speed of 10000 rpm, an air inlet temperature of 130° C., and an air outlet temperature of 70° C.;

[0061] (2) The carbon black granulated powder obtained by spray granulation was mixed with silicon powder in a molar ratio of 1.03:1.0. The obtained powder was placed in a crucible and placed in a sintering furnace. The vacuum degree of the sintering furnace was 5×10 -4 Pa, and then high-purity argon is introduced to normal pressure. The air in the sintering furnace is removed by three cycles. The temperature is raised to 1350°C and maintained for 3 hours. The temperature is then raised to 1650°C and maintained for 3 hours. The silicon carbide ceramic powder is cooled to room temperature and then ground for 3 hours.

[0062] Example 8

[0063] The difference between this embodiment and embodiment 1 is that in step (2), the carbon black granulated powder obtained by spray granulation is mixed with silicon powder in a molar ratio of 1.0:1.1, the obtained powder is placed in a crucible and placed in a sintering furnace, and the vacuum degree of the sintering furnace is 5×10 -4 Pa, and then high-purity argon is introduced to normal pressure, and the air in the sintering furnace is removed by three cycles. The temperature is raised to 1350°C and maintained for 3 hours, and then the temperature is raised to 1650°C and maintained for 3 hours. The silicon carbide ceramic powder is obtained by cooling to room temperature.

[0064] Comparative Example 1

[0065] The difference between this comparative example and Example 1 is that in step (1), 10 parts of carbon black powder (particle size 0.1 μm), 1.0 part of phenolic resin (viscosity 5000 mPa·s) and 0.05 part of polyethylene glycol are put into a ball mill, 35 parts of ethanol are added, and the mixture is ball-milled and mixed at 300 rpm for 2 h to obtain a carbon powder slurry, which is then spray granulated by a spray granulation drying equipment under a nitrogen atmosphere, the slurry feed rate is 50 rpm, the centrifugal disk speed is 10000 rpm, the air inlet temperature is 130°C, and the air outlet temperature is 70°C.

[0066] Comparative Example 2

[0067] The difference between this comparative example and Example 1 is that in step (1), 10 parts of carbon black powder (particle size 0.1 μm), 0.05 parts of polyethylene glycol and 0.01 parts of ammonium carbonate are put into a ball mill, 35 parts of ethanol are added, and the mixture is ball-milled and mixed at 300 rpm for 2 h to obtain a carbon powder slurry, which is then spray granulated by a spray granulation drying equipment under a nitrogen atmosphere, with a slurry feed rate of 50 rpm, a centrifugal disk speed of 10000 rpm, an air inlet temperature of 130°C, and an air outlet temperature of 70°C.

[0068] Comparative Example 3

[0069] The difference between this comparative example and Example 1 is that in step (1), 10 parts of carbon black powder (particle size 0.1 μm), 1.0 part of polyvinyl butyral, 0.05 parts of polyethylene glycol and 0.01 parts of ammonium carbonate are put into a ball mill, 35 parts of ethanol are added, and the mixture is ball-milled and mixed at 300 rpm for 2 h to obtain a carbon powder slurry, which is then spray granulated by a spray granulation drying equipment under a nitrogen atmosphere, the slurry feed rate is 50 rpm, the centrifugal disk speed is 10000 rpm, the air inlet temperature is 130°C, and the air outlet temperature is 70°C.

[0070] In Example 1-3, carbon black powder with a particle size of 0.1 to 1.0 μm is used as a raw material, combined with a suitable amount of a binder, a dispersant and a pore-forming agent, and a carbon black granulated powder with a controllable particle size is obtained by spray granulation, and then mixed with silicon powder and sintered at high temperature to finally obtain a silicon carbide ceramic powder with a median particle size of 10.6 to 107.4 μm; In Example 4-5, a higher content of a pore-forming agent is added, which will cause the carbon black granulated powder to produce more pores during the high-temperature sintering process, resulting in an unstable structure, so that the particle size of the final silicon carbide ceramic powder is smaller; In Example 6, an excessively high content of a pore-forming agent is used, and the carbon powder and the obtained silicon carbide ceramic powder have more pores, an unstable structure, and the particle size of the obtained silicon carbide ceramic powder is more significantly reduced; In Example 7, no carbon removal treatment is performed, and the purity of the obtained silicon carbide ceramic powder decreases, and it contains some residual carbon; In Example 8, less carbon powder and more silicon powder are used to prepare silicon carbide ceramic powder, and the purity of the obtained silicon carbide ceramic powder decreases, containing some residual silicon; in Comparative Example 1, no porogen is added, and no continuous pores are generated inside the carbon black granulated powder during the high-temperature reaction, and the molten silicon liquid cannot effectively penetrate into the carbon black granulated powder for sufficient reaction, resulting in the presence of unreacted carbon in the final silicon carbide powder; in Comparative Example 2, no phenolic resin is added, and the carbon black powder cannot be bonded and shaped, and there is no carbon skeleton to maintain the morphological characteristics of the carbon black powder, making the structure and particle size of the obtained silicon carbide ceramic powder uncontrollable; Comparative Example 3 uses a thermoplastic resin, which results in the overall collapse and adhesion of the carbon black granulated powder obtained by spray granulation during the high-temperature sintering process, making it difficult to control the particle size and morphology of the silicon carbide powder generated after the high-temperature reaction.

[0071] Finally, it should be noted that the specific embodiments described herein are merely examples of the spirit of the present invention, and are not intended to limit the implementation methods of the present invention. Those skilled in the art of the present invention may make various modifications or supplements to the described embodiments or replace them in similar ways. It is not necessary and impossible to provide all examples of all implementation methods here. However, these obvious changes or modifications derived from the essential spirit of the present invention still fall within the scope of protection of the present invention, and interpreting them as any additional limitation is contrary to the spirit of the present invention.

Claims

1. A method for preparing high-purity silicon carbide ceramic powder with controllable particle size, characterized in that: The following steps are involved: (1) mixing carbon black powder, a binder, a dispersant, a pore-forming agent and a solvent by ball milling to obtain a carbon powder slurry, and obtaining carbon black granulated powder by spray granulation; (2) The carbon black granulated powder obtained by spray granulation is mixed with silicon powder and then sintered at high temperature.

2. The preparation method according to claim 1, characterized in that: The particle size of the carbon black powder in step (1) is less than 1.5 μm.

3. The preparation method according to claim 1, characterized in that: The binder in step (1) is a thermosetting resin; and / or the pore-forming agent is a compound that can generate gas upon high temperature decomposition.

4. The preparation method according to claim 3, characterized in that: The viscosity of the thermosetting resin is 3000 to 8000 mPa·s.

5. The preparation method according to claim 1, characterized in that: In step (1), the masses of the binder, dispersant and pore-forming agent are 1-30wt%, 0.5-3.0wt% and 0.1-1.0wt% of the mass of the carbon black powder respectively.

6. The preparation method according to claim 1, characterized in that: The mass of the solvent in step (1) is 1 to 10 times the mass of the carbon black powder, the binder, the dispersant and the pore-forming agent.

7. The preparation method according to claim 1, characterized in that: In step (2), the molar ratio of carbon black granulated powder to silicon powder is 1.0-1.5:1.

0.

8. The preparation method according to claim 1, characterized in that: In step (2), the high temperature sintering is first carried out at 1100-1350° C. for 1-12 hours, and then the temperature is raised to 1500-1900° C. for 2-20 hours.

9. The preparation method according to claim 1, characterized in that: The silicon carbide ceramic powder obtained after high-temperature sintering is subjected to decarbonization treatment and shaping treatment in sequence.

10. A high-purity silicon carbide ceramic powder with controllable particle size, characterized in that: The method is prepared according to claim 1.

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