KR20230130862A - Sintered SiC ceramics with high specific stiffness and composition for producing the same - Google Patents

Abstract

The present invention relates to a silicon carbide (SiC) material that can be used as a reflector material and its composition, which is manufactured by mixing submicron silicon carbide (SiC) powder with submicron boron carbide (B ₄ C) powder and a precursor of nanocarbon. By sintering at a temperature of 2,050°C to 2,200°C using a combination of raw materials, the specific rigidity produced by the solid-state sintering process ranges from 141×10 ⁶ m ² s ^-2 to 155×10 ⁶ m ² s ^-2 , and the grain boundary and a silicon carbide sintered body containing a plurality or more of boron carbide (B ₄ C) particles segregated at a triple point and having a porosity of 0.3% or less, and a composition for producing the same.

Description

Sintered SiC ceramics with high specific stiffness and composition for producing the same}

The present invention relates to a silicon carbide sintered body having high specific rigidity from a silicon carbide (SiC) material that can be used as a material for a reflector and a composition for producing a silicon carbide sintered body.

Specific stiffness (specific modulus) is a physical property of a material consisting of the material's density and elastic modulus (Young's modulus). High specific stiffness materials are widely used in aerospace applications where minimum structural weight is required, and specific stiffness is defined by Equation 1 below:

[Equation 1]

Specific stiffness = E / d

In Equation 1, E is Young's modulus, d is density, and when the units of elastic modulus and density are GPa and g/cm ³ , respectively, the specific stiffness has a unit of 10 ⁶ m ² s ^-2 .

Silicon carbide (SiC) is a material with excellent stability and strength at high temperatures and excellent physical properties such as heat resistance and thermal conductivity. It is used in gas turbines, fusion reactors, semiconductor fixtures, wear-resistant materials, automobile parts, or chemical plants. It is mainly used for etc.

However, silicon carbide material has a low specific rigidity, making it difficult to apply to parts that require high specific rigidity.

Korean Patent No. 10-1620510

In order to solve the above problems, the present invention is to increase the specific rigidity of the silicon carbide sintered body by controlling the addition amount of boron carbide (B ₄ C), which has an elastic modulus similar to that of silicon carbide (SiC) material but can lower the density. The purpose is to provide a silicon carbide sintered body having a and a composition for producing such a silicon carbide sintered body.

In order to achieve the above object, the silicon carbide sintered body of the present invention is a silicon carbide sintered body, and the grain boundary of the silicon carbide sintered body and the crystal grain interface forming the silicon carbide sintered body meet with each other and form a plurality of particles segregated at the middle point of the image. It contains boron carbide (B ₄ C) particles.

The silicon carbide sintered body has a specific rigidity of 141×10 ⁶ m ² s ^-2 to 155×10 ⁶ m ² s ^-2 and a porosity of 0.3% or less.

The silicon carbide sintered body uses a composition containing ceramic powder made of alpha-phase silicon carbide (α-SiC), boron carbide (B ₄ C), and nano-sized carbon (hereinafter referred to as 'nano carbon') and an organic binder. It is manufactured through a sintering process.

Based on 100 parts by weight of the total ceramic powder, the alpha phase silicon carbide (α-SiC) is 67.5 parts by weight to 92.0 parts by weight, the boron carbide (B ₄ C) is 7.0 parts by weight to 30.0 parts by weight, and the nano carbon is It is preferable to include 1.0 to 2.5 parts by weight.

The particle size of the alpha-phase silicon carbide (α-SiC) and boron carbide (B ₄ C) is preferably 0.1 ㎛ or more and less than 1 ㎛.

The nano carbon is converted from any one type of carbon precursor selected from the group consisting of phenol resin, furfuryl alcohol resin, xylene resin, and combinations thereof, and the nano carbon Carbon preferably has a particle size of 0.1 nm to 70 nm.

The organic binder included in the composition is preferably at least one selected from polyvinyl butyral, polyethylene glycol, and polymethyl methacrylate.

Based on 100 parts by weight of the total composition, the organic binder preferably contains 0.2 to 3.5 parts by weight.

The composition for producing a silicon carbide sintered body of the present invention for achieving another purpose includes a ceramic powder made of alpha-phase silicon carbide (α-SiC), boron carbide (B ₄ C), and carbon, and an organic binder, and the organic binder Based on 100 parts by weight of _the total ceramic powder excluding It may contain 1.0 to 2.5 parts by weight.

In the composition for producing a silicon carbide sintered body of the present invention, the particle size of the alpha-phase silicon carbide (α-SiC) is preferably 0.1 ㎛ or more and less than 1 ㎛, and the particle size of the boron carbide (B ₄ C) is preferably 0.1 ㎛ or more and less than 1 ㎛. .

In the composition for producing a silicon carbide sintered body of the present invention, the nano carbon is any one selected from the group consisting of phenol resin, furfuryl alcohol resin, xylene resin, and combinations thereof. It is converted from a carbon precursor, and the nano-carbon preferably has a particle size of 0.1 nm to 70 nm.

In the composition for producing a silicon carbide sintered body of the present invention, it is preferable to use at least one organic binder selected from polyvinyl butyral, polyethylene glycol, and polymethyl methacrylate. .

Based on 100 parts by weight of the total composition, the organic binder preferably contains 0.2 to 3.5 parts by weight.

In general, when the elastic modulus of the silicon carbide material is 450 GPa and the density is the theoretical density of 3.21 g/cm ³ , the maximum specific stiffness of the silicon carbide sintered body is about 140.2×10 ⁶ m ² s ^-2 . However, the silicon carbide sintered body of the present invention exceeds the theoretical limit of 140.2 × 10 ⁶ m ² s ^-2 of existing silicon carbide materials, and has a specific rigidity of 141 × 10 ⁶ m ² s ^-2 to 155 × 10 ⁶ m ² s ^{- 2} , the porosity is 0.3% or less, and the microstructural feature is that there are a plurality of boron carbide (B ₄ C) particles segregated at the triple point formed when the grain boundaries of the silicon carbide sintered body and the grain interfaces forming the silicon carbide sintered body meet each other. have

The silicon carbide sintered body of the present invention, which has such characteristics, has the characteristic of high specific rigidity and is suitable for use as a material for a reflector of an optical system operated in space.

Figure 1 is an observation of the microstructure of a silicon carbide sintered body according to an embodiment of the present invention.
Figure 2 is a flowchart of a method for manufacturing a silicon carbide sintered body according to the present invention.

Hereinafter, the silicon carbide sintered body of the present invention will be described in detail. This is an example and can be implemented in various different forms by those skilled in the art to which the present invention pertains, so it is not limited to the description here.

The silicon carbide sintered body of the present invention has a specific rigidity in the range of 141 × 10 ⁶ m ² s ^-2 to 155 × 10 ⁶ m ² s ^-2 through a solid-state sintering process, has a porosity of 0.3% or less, and the grain boundaries of the silicon carbide sintered body and a plurality or more of boron carbide (B ₄ C) particles segregated at the midpoint of the silicon carbide sintered body, which is formed when the grain interface and the crystal grain interface meet each other.

The composition for manufacturing the silicon carbide sintered body for producing the silicon carbide sintered body having the above characteristics includes ceramic powder and an organic binder made of alpha-phase silicon carbide (α-SiC), boron carbide (B ₄ C), and nano carbon. .

Based on 100 parts by weight of the entire ceramic powder excluding the organic binder, the alpha phase silicon carbide (α-SiC) is 67.5 parts by weight to 92.0 parts by weight, the boron carbide (B ₄ C) is 7.0 parts by weight to 30.0 parts by weight, and The carbon contains 1.0 to 2.5 parts by weight.

The alpha-phase silicon carbide (α-SiC) and the boron carbide (B ₄ C) are particles having a sub-micron size, and the alpha-phase silicon carbide (α-SiC) and the boron carbide (B ₄ C) are particles having a submicron size. The particle size of C) is 0.1 ㎛ or more and less than 1 ㎛.

The boron carbide (B ₄ C) is segregated at the grain boundaries during sintering and plays a role in lowering the grain boundary energy to promote grain boundary diffusion. Additionally, as sintering progresses, a phase is formed when the grain interfaces forming the silicon carbide sintered body meet each other. It is segregated at the center and plays a role in suppressing grain growth of silicon carbide particles.

The nano carbon is converted from a carbon precursor, and the carbon precursor is any selected from the group consisting of phenol resin, furfuryl alcohol resin, xylene resin, and combinations thereof. Use type 1.

Specifically, nanocarbon is nano-sized carbon with a particle size of 0.1 nm to 70 nm produced by thermal decomposition of the carbon precursor, and the nanocarbon may be amorphous, crystalline, or a mixture thereof.

Nanocarbon produced by thermal decomposition of the carbon precursor reacts with the oxide film (SiO ₂ ) on the surface of the silicon carbide (SiC) powder during sintering through a reaction shown in Scheme 1 below, and serves to remove the oxide film (SiO ₂ ). do.

Removal of the oxide film (SiO ₂ ) on the surface of the silicon carbide powder increases the surface energy of the silicon carbide (SiC) powder, thereby increasing the driving force for sintering.

[Scheme 1]

SiO ₂ + 3C → SiC + 2CO↑

The organic binder included in the composition for producing a silicon carbide sintered body may be one or more selected from polyvinyl butyral, polyethylene glycol, and polymethyl methacrylate, and the total composition may be 100%. Based on parts by weight, the organic binder contains 0.2 to 3.5 parts by weight.

Figure 1 is an observation of the microstructure of a silicon carbide sintered body according to an embodiment of the present invention.

In Figure 1, arrows indicate boron carbide (B ₄ C) particles segregated at grain boundaries and triple points, and as shown, in the microstructure of the silicon carbide sintered body manufactured according to an embodiment of the present invention, particles segregated at grain boundaries and triple points. It can be confirmed that it contains boron carbide (B ₄ C) particles.

The method of manufacturing the silicon carbide sintered body as described above includes the steps of (a) preparing a mixture by mixing a binder containing silicon carbide, boron carbide, a carbon precursor, and an organic binder (S100), (b) as shown in FIG. It includes the step of granulating the mixture to produce granules (S200), (c) manufacturing the molded body by molding the granules (S300), and (d) sintering the molded body (S400).

The step (a) (S100) is performed by adding boron carbide (B ₄ C), a carbon precursor, and an organic binder to alpha-phase silicon carbide (α-SiC) powder, using silicon carbide balls and ethyl alcohol as a solvent. It is preferable to prepare the mixture by mixing using a typical ball milling process for 12 to 36 hours.

The solvent is not limited to ethyl alcohol, and any solvent that can dissolve the carbon precursor may be used.

In step (b) (S200), the mixture prepared through step (a) (S100) is manufactured into granules using a typical spray dryer.

Step (c) (S300) is a step of manufacturing the granules prepared in step (b) into a molded body of a certain shape, using any one of cold isostatic pressure forming, uniaxial pressure molding, and a mixed molding method of uniaxial pressure molding and cold isostatic pressure forming. It doesn't matter if you use any of the methods.

Among the above forming methods, when cold isostatic pressing is used, the forming pressure is preferably pressurized to a pressure of 150 MPa to 300 MPa, and when using the mixed forming method of uniaxial pressing and cold isostatic pressing, the pressure during uniaxial pressing is Pressurization is preferably performed at a pressure of 10 MPa to 50 MPa, and the pressure of cold isostatic forming is preferably applied at a pressure of 150 MPa to 300 MPa.

Step (d) (S400) is a step of manufacturing a silicon carbide sintered body by sintering the molded body manufactured in step (c) (S300).

The step (d) (S400) is preferably performed by pressure sintering, spark plasma sintering, or normal pressure sintering at a temperature range of 2,050°C to 2,200°C using a conventional graphite furnace, and the holding time at the highest temperature is 1 hour. Preferably it is from 6 hours.

During the sintering process, it is preferable to maintain a vacuum in the range of 0.1 torr to 80 torr for 0.5 to 3 hours at a temperature range of 350°C to 750°C before reaching the maximum temperature for thermal decomposition of the organic binder.

In addition, in order to remove the oxide film (SiO ₂ ) on the surface of the silicon carbide (SiC) powder, it is preferable to maintain the vacuum in the range of 0.1 torr to 80 torr for 0.5 to 3 hours at a temperature of 1,450 ℃ to 1,600 ℃ during the sintering process. do.

In step (d) (S400), the sintering atmosphere is preferably sintered in a vacuum ranging from 0.1 torr to 80 torr in the temperature range from room temperature to 1,600°C, and an argon atmosphere during the sintering temperature above 1,600°C and the holding time at the highest temperature. It is desirable to sinter in .

Hereinafter, the present invention will be described in detail through examples. The presented embodiments are illustrative and the scope of the present invention is not limited thereto.

Manufacturing Example 1

To produce a silicon carbide sintered body by adding alpha-phase silicon carbide (α-SiC) powder with an average particle diameter of 0.5㎛, boron carbide (B ₄ C) powder with an average particle diameter of 0.5㎛, and phenol resin powder as a carbon precursor. The mixture was prepared.

Here, the yield of carbon derived from the phenol resin powder was 60%, so taking this into account, a mixture was prepared by adding phenol resin in an amount to calculate carbon.

Based on 100 parts by weight of the mixture composition, 80 parts by weight of ethyl alcohol was additionally added, 0.5 parts by weight of polyvinyl butyral was added as an organic binder, and ball milled for 24 hours using a polypropylene container and silicon carbide balls to uniformly distribute the mixture. A mixture slurry was prepared.

The ball milled slurry was used to prepare granules using a conventional spray dryer.

The prepared granules were placed in a mold to prepare a preformed body at a pressure of 20 MPa, which was then subjected to cold isostatic pressing at a pressure of 204 MPa to produce a cylindrical body with a diameter of 30 mm × height of 16 mm.

The silicon carbide sintered body was manufactured by solid-phase sintering the molded body under argon atmosphere at a temperature of 2,050°C and a pressure of 35 MPa for 2 hours.

Production example 2

In Preparation Example 2, the mixture slurry and granules were prepared in the same manner as Preparation Example 1, except that the prepared granules were placed in a certain mold to prepare a preformed body at a pressure of 30 MPa, and then subjected to cold isostatic pressure forming (cold) at a pressure of 200 MPa. A cylindrical molded body with a diameter of 30 mm × height of 26 mm was manufactured by isostatic pressing.

The silicon carbide sintered body was manufactured by solid-phase sintering the molded body under argon atmosphere at a temperature of 2,050°C and a pressure of 35 MPa for 2 hours.

Production example 3

To produce a silicon carbide sintered body by adding alpha-phase silicon carbide (α-SiC) powder with an average particle diameter of 0.5㎛, boron carbide (B ₄ C) powder with an average particle diameter of 0.5㎛, and phenol resin powder as a carbon precursor. The mixture was prepared.

Here, since the yield of carbon in the phenol resin is 60%, a mixture was prepared by adding an amount of phenol resin to calculate carbon, taking this into consideration.

Based on 100 parts by weight of the mixture composition, 75 parts by weight of ethyl alcohol was additionally added, 0.3 parts by weight of polyethylene glycol was added as an organic binder, and ball milled for 24 hours using a polypropylene container and silicon carbide balls to produce a uniform mixture slurry. was manufactured.

The ball milled slurry was used to prepare granules using a conventional spray dryer.

The prepared granules were placed in a mold to produce a preformed body at a pressure of 25 MPa, and then cold isostatic pressed at a pressure of 200 MPa to form a rectangular parallelepiped body measuring 40 mm × 40 mm × 26 mm. Manufactured.

A silicon carbide sintered body was manufactured by solid-phase sintering the molded body in an argon atmosphere at 2,150°C for 1 hour without applying pressure.

<Examples 1 to 5>

In Examples 1 to 5, silicon carbide sintered bodies were manufactured in the same manner as Preparation Example 1 with the compositions shown in Table 1 below.

<Example 6 to Example 8>

In Examples 6 to 8, silicon carbide sintered bodies were manufactured in the same manner as Preparation Example 2 with the compositions shown in Table 1 below.

<Example 9>

In Example 9, a silicon carbide sintered body was manufactured in the same manner as Preparation Example 3 with the composition shown in Table 1 below.

<Comparative Example 1>

In Comparative Example 1, unlike Examples 1 to 5, the content of boron carbide was different from 7.0 to 30.0 parts by weight as shown in Table 1, so 0.1 parts by weight of boron carbide was added, and nano carbon was in the range of 1.0 to 2.5 parts by weight. A silicon carbide sintered body was manufactured in the same manner as in Preparation Example 1 by adding 1.5 parts by weight contained in .

<Comparative Example 2>

In Comparative Example 2, unlike Examples 1 to 5, the content of nanocarbon was outside the range of 1.0 to 2.5 parts by weight and 0.2 parts by weight was added, as shown in Table 1 below, and the content of boron carbide was 7.0 to 30.0 parts by weight. A silicon carbide sintered body was manufactured in the same manner as in Preparation Example 1 by adding 7.0 parts by weight within the range.

division
(part by weight) Alpha phase silicon carbide
(α-SiC) boron carbide
(B ₄ C) nano carbon Comparative Example 1 98.4 0.1 1.5 Comparative Example 2 92.8 7.0 0.2 Example 1 91.5 7.0 1.5 Example 2 88.5 10.0 1.5 Example 3 83.5 15.0 1.5 Example 4 73.5 25.0 1.5 Example 5 68.5 30.0 1.5 Example 6 87.5 10.0 2.5 Example 7 91.0 7.0 2.0 Example 8 88.0 10.0 2.0 Example 9 89.5 8.0 2.25

The porosity, sintered density, elastic modulus, and specific stiffness of the silicon carbide sintered bodies of Examples 1 to 9, Comparative Example 1, and Comparative Example 2 were measured by the following methods, and the results are shown in Table 2 below.

Porosity was measured using the Archimes method by manufacturing five specimens measuring 5 mm × 5 mm × 5 mm from each sintered body and showing the average value.

The sintered density was measured from the volume and weight after cutting and polishing a 20mm × 20mm × 7mm specimen from the sintered body.

The elastic modulus was measured using the ultrasonic pulse-echo technique using the same specimen from which the density was measured, and the average value was shown.

The specific stiffness of the silicon carbide sintered body was calculated using Equation 1 below using the measured density and elastic modulus.

[Equation 1]

Specific stiffness = E / d

In Equation 1, E is Young's modulus and d is density.

division Sintering conditions porosity
(%) Sintered Density
(g/ ^cm3 ) modulus of elasticity
(GPa) Specific rigidity
(×10 ⁶ m ² s ^-2 ) temperature
(℃) Pressure (MPa) hour
(hour) Comparative Example 1 2,050 35 2 9.5 2.901 308.0 106.2 Comparative Example 2 2,050 35 2 8.5 2.923 331.7 113.5 Example 1 2,050 35 2 0.01 3.150 454.2 144.2 Example 2 2,050 35 2 0.01 3.123 452.9 145.0 Example 3 2,050 35 2 0.01 3.088 456.7 147.9 Example 4 2,050 35 2 0.01 3.010 459.8 152.8 Example 5 2,050 35 2 0.01 2.964 450.6 152.0 Example 6 2,050 35 2 0.02 3.105 441.1 142.1 Example 7 2,050 35 2 0.01 3.150 450.6 143.0 Example 8 2,050 35 2 0.01 3.137 462.5 147.4 Example 9 2,150 0.1 One 0.08 3.099 442.8 142.9

As shown in Table 2, the silicon carbide sintered body of Examples 1 to 5 had a porosity of 0.01% and a specific stiffness in the range of 144.2 × 10 ⁶ m ² s ^-2 to 152.8 × 10 ⁶ m ² s ^-2 . .

The silicon carbide sintered bodies of Examples 6 to 8 had a porosity of 0.01% to 0.02% and a specific stiffness in the range of 142.1 × 10 ⁶ m ² s ^-2 to 147.4 × 10 ⁶ m ² s ^-2 .

Additionally, in the case of the silicon carbide sintered body of Example 9, the porosity was 0.08% and the specific rigidity was 142.9×10 ⁶ m ² s ^-2 .

On the other hand, Comparative Example 1 was pressurized and solid-phase sintered under the same conditions as Example 1, but the porosity was very high at 9.5% and the specific stiffness was 106.2×10 ⁶ m ² s ^-2 , which was much lower than that of Examples 1 to 5. showed stiffness.

In the case of Comparative Example 2, pressure solid phase sintering was performed under the same conditions as Example 1, but the porosity was very high at 8.5% and the specific stiffness was 113.5×10 ⁶ m ² s ^-2 , which was much lower than that of Examples 1 to 5. showed stiffness.

Therefore, in Comparative Example 1 and Comparative Example 2, the porosity of the silicon carbide sintered body was too high at 8.5% or more, and the specific stiffness was very low in the range of 106.2 × 10 ⁶ m ² s ^-2 to 113.5 × 10 ⁶ m ² s ^-2 . The physical properties are clearly distinguished from the silicon carbide sintered body such as Examples 1 to 9, which has a porosity of 0.3% or less and a specific stiffness in the range of 141 × 10 ⁶ m ² s ^-2 to 155 × 10 ⁶ m ² s ^-2. .

In general, the theoretical density of silicon carbide (SiC) is 3.21 g/cm ³ and the Young's modulus of dense silicon carbide (SiC) material is about 450 GPa, and the theoretical density of boron carbide (B ₄ C) is 2.52 g/cm ³ and the dense material has a Young's modulus of about 450 GPa. The Young's modulus of boron carbide (B ₄ C) material ranges from 362 GPa to 472 GPa.

Accordingly, as described above, the present invention replaces some of the silicon carbide (SiC) particles with boron carbide (B ₄ C) particles in the raw material combination of silicon carbide (SiC), so that the elastic modulus is similar to that of the silicon carbide (SiC) material, but the density is increased. By lowering it, the specific stiffness is improved from 141×10 ⁶ m ² s ^-2 to 155×10 ⁶ m ² s ^-2 , and it has a microstructural feature with a plurality of boron carbide (B ₄ C) particles segregated at grain boundaries and triple points. , to manufacture a silicon carbide sintered body with a porosity of 0.3% or less.

Claims (17)

In the silicon carbide sintered body,
A silicon carbide sintered body comprising a plurality of boron carbide (B ₄ C) particles segregated at the grain boundaries of the silicon carbide sintered body and at the midpoint of the image where the grain interfaces forming the silicon carbide sintered body meet each other. According to paragraph 1,
The silicon carbide sintered body is characterized in that the specific rigidity is 141 × 10 ⁶ m ² s ^-2 to 155 × 10 ⁶ m ² s ^-2 . According to paragraph 1,
The silicon carbide sintered body is characterized in that the silicon carbide sintered body has a porosity of 0.3% or less. According to paragraph 1,
The silicon carbide sintered body,
It is manufactured through a sintering process using a composition containing ceramic powder made of alpha-phase silicon carbide (α-SiC), boron carbide (B ₄ C) and nano carbon and an organic binder,
Based on 100 parts by weight of total ceramic powder,
67.5 to 92.0 parts by weight of alpha-phase silicon carbide (α-SiC);
7.0 to 30.0 parts by weight of boron carbide (B ₄ C); and
A silicon carbide sintered body comprising 1.0 to 2.5 parts by weight of the nanocarbon. According to paragraph 4,
The alpha-phase silicon carbide (α-SiC) is a silicon carbide sintered body, characterized in that the particle size is 0.1 ㎛ or more and less than 1 ㎛. According to paragraph 4,
The boron carbide (B ₄ C) is a silicon carbide sintered body, characterized in that the particle size is 0.1 ㎛ or more and less than 1 ㎛. According to paragraph 4,
The nano-carbon is a silicon carbide sintered body, characterized in that the particle size is 0.1 ㎚ to 70 ㎚. According to paragraph 4,
The nano-carbon is characterized in that it is converted from any one type of carbon precursor selected from the group consisting of phenol resin, furfuryl alcohol resin, xylene resin, and combinations thereof. Silicon carbide sintered body. According to paragraph 4,
The organic binder is a silicon carbide sintered body, characterized in that at least one selected from polyvinyl butyral, polyethylene glycol, and polymethyl methacrylate. According to paragraph 4,
Based on 100 parts by weight of the total composition,
The organic binder is a silicon carbide sintered body, characterized in that it contains 0.2 to 3.5 parts by weight. Contains ceramic powder and an organic binder made of alpha-phase silicon carbide (α-SiC), boron carbide (B ₄ C), and nano carbon,
Based on 100 parts by weight of total ceramic powder excluding the organic binder,
The alpha phase silicon carbide (α-SiC) is 67.5 parts by weight to 92.0 parts by weight;
The boron carbide (B ₄ C) is 7.0 parts by weight to 30.0 parts by weight; and
A composition for producing a silicon carbide sintered body, characterized in that it contains 1.0 to 2.5 parts by weight of carbon. According to clause 11,
A composition for producing a silicon carbide sintered body, wherein the alpha-phase silicon carbide (α-SiC) particles have a particle size of 0.1 ㎛ or more and less than 1 ㎛. According to clause 11,
A composition for producing a silicon carbide sintered body, wherein the boron carbide (B ₄ C) particles have a particle size of 0.1 ㎛ or more and less than 1 ㎛. According to clause 11,
A composition for producing a silicon carbide sintered body, characterized in that the nano-carbon has a particle size of 0.1 nm to 70 nm. According to clause 11,
The nano-carbon is characterized in that it is converted from any one type of carbon precursor selected from the group consisting of phenol resin, furfuryl alcohol resin, xylene resin, and combinations thereof. Composition for producing silicon carbide sintered body. According to clause 11,
A composition for producing a silicon carbide sintered body, wherein the organic binder is at least one selected from polyvinyl butyral, polyethylene glycol, and polymethyl methacrylate. According to clause 11,
Based on 100 parts by weight of the total composition,
A composition for producing a silicon carbide sintered body, characterized in that it contains 0.2 to 3.5 parts by weight of the organic binder.

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