KR20100090377A - High-temperature oxidative resistant porous nano silicon carbide and manufacturing method thereof - Google Patents

Abstract

PURPOSE: A porosity nano silicon carbide and a manufacturing method thereof are provided to simplify processing conditions and prevent cracks. CONSTITUTION: A porosity nano silicon carbide manufacturing method includes next steps. A polymer precursor and silicone compound are mixed with solvent. The compound which is obtained in the stage is electro-spined in a sphere or fiber form. A heat-treatment process is executed for the electrospinning result. The polymer precursor is selected among petroleum pitch, coal type pitch, polyimide, polybenzimidazole, poly acrylonitrile, polyaramide, polyaniline, mesophase pitch, furfuryl alcohol, phenol, cellulose, sucrose, polyvinylchloride and their mixture.

Description

High-temperature oxidative resistant porous nano silicon carbide and manufacturing method

The present invention relates to a porous nano-silicon carbide having a oxidation resistance at a high temperature and a method of manufacturing the same.

The present invention relates to a method for producing porous silicon carbide used in industrial fields such as steelmaking, steelmaking, chemical industry, incinerators, heat-use equipment, and the like.

Conventional representative methods for producing silicon carbide include thermal spraying, melt spinning, and wet spinning. Usually, thermal spraying is used for the form of powder, and melt spinning and wet spinning are used to obtain the form of fibers. Thermal spraying is difficult to obtain a certain form of powder, it is difficult to control the desired form. In addition, in the case of the melt spinning method, the processing conditions are difficult, and in the case of the wet spinning method, the solvent has to be removed.

When the electrospinning method is applied to the production of silicon carbide as compared to the conventional method, it is expected that the particle shape, size, structure, etc. can be controlled, and the silicon carbide can be economically and simply manufactured.

Ceramics possess mechanical properties such as high strength, high hardness, and wear resistance, as well as excellent oxidation resistance, corrosion resistance, low thermal conductivity, and thermal properties such as high thermal shock and high temperature strength due to thermal expansion coefficient. And a lot of investment in commercialization. Among the ceramics, silicon carbide has strong covalent bonds due to the characteristics of the material and thus has low sinterability. Sintering refers to a phenomenon in which a bond formed between a powder is hardened when a nonmetal or metal powder is formed by heat treatment at a temperature below the melting point. It is an important technique for producing urine pressure products or ceramics, powder metallurgy, cermet, and the like. The driving force of the sintering is the extra surface energy of the powder, ie the sum of the surface energies in the state where the powder is simply aggregated is thermodynamically non-equilibrium, not the minimum. When the powder is heat-treated, mass transfer occurs in a direction to reduce the surface energy, that is, in a direction in which the surface area is reduced, thereby causing bonding of the particles. The microstructure change in the sintering process can be divided into three stages: initial stage, intermediate stage and final stage. In the early stages, adhesions between particles occur, which in turn increases the area of the area, which is called cervical growth. At this stage, the relative density is about 0.5 to 0.6 and the shrinkage is about 4% to 5%. In the middle stage, the channel-shaped gap is narrowed gradually, so that the relative density is 0.6 to 0.95 and the shrinkage ratio is about 5% to 20%. The relative density in the boil stage is not less than 0.95, leaving pores (pores) inside the polyhedralized particle angles or particles. The pores that communicate with the outside air are called open pores, and the pores that do not pass through are called closed pores. In this boil stage, densification occurs as the pores disappear. Therefore, porous ceramics with many pores and dense ceramics with many pores are different depending on the pores and accordingly, their function is also different.

The conventional method of manufacturing porous silicon carbide ceramics is a method of manufacturing by adding a pore material. This technique is to coat the silicon carbide suspension on the surface of organic pore materials such as starch, foamed resin, urethane foam, etc. using a coating method such as wash coating or dip coating, and then dewatered to remove residual suspension on the surface of the organic pore material. To dry. The fine powder of silicon carbide is applied and the dried organic pore is heat-treated at a temperature of about 800 ° C. or more to completely burn the organic matter. Next, porous silicon carbide ceramics are prepared by atmospheric sintering at a temperature of about 1,800 ° C. or higher and a nitrogen atmosphere. The conventional method of manufacturing porous silicon carbide includes a ceramic suspension coating process, a heat treatment, and a sintering process at a high temperature, so that the overall process is complicated and the energy cost for manufacturing is increased, resulting in an increase in the cost of the final finished product. In addition, if the porosity is to be increased, the amount of pore added is also large, and when a large amount of organic compound-based pore is added, the amount of gases such as organic volatiles and carbon dioxide generated in the degreasing (calcination) step is also increased. Also grows. The calcined (degreasing) body or the sintered body obtained under such manufacturing conditions may be cracked, torn, or cut due to the generation of gas and the heat of combustion, or defective parts such as pores due to aggregation of organic porous materials added in a large amount. There is a problem that occurs. In addition, in the case of using the organic pore material, the porosity can be increased by increasing the amount of the pore material added, but there is a problem that the pore diameter is also increased at the same time. In order to solve this problem, various studies on the basic raw materials of porous silicon carbide ceramics are being conducted.

The present invention has been made to solve the above problems, and to provide a method that can be economically and conveniently produced nano-sized porous silicon carbide having oxidation resistance at high temperature.

In addition, there is another object to provide a nano-sized porous silicon carbide having oxidation resistance at a high temperature produced by the manufacturing method.

The present invention provides a method for producing porous nano silicon carbide having oxidation resistance at high temperature, and the method for preparing porous nano silicon carbide having oxidation resistance at high temperature according to the present invention comprises: (1) polymer precursor and silicon compound; Mixing; (2) electrospinning the mixture obtained through the process of 'step (1)' into a spherical or fibrous form; (3) heat-treating the result of the electrospinning result obtained through the process of 'step (2)'.

In the mixture obtained through the process of 'step (1)', the molar ratio of carbon (C) and silicon (Si) is preferably 3 to 7: 1.

The viscosity of the mixture obtained through the process of 'step (1)' is preferably 100 to 800 cP.

Electrospinning conditions in the electrospinning process of the 'step (2)', the voltage is preferably 5 to 50kV, radiation amount 1 to 20 ml / h.

In addition, by adjusting the viscosity conditions and the electrospinning conditions of the mixture, the shape can be adjusted, the viscosity of the mixture obtained through the process of 'step (1)' in the range of 100 to 500 cP, and the 'step (2 When the electrospinning conditions of) 'are electrospun in the range of a voltage of 20 to 50 kV and a radiation dose of 1 to 10 ml / h, a spherical shape can be obtained.

In addition, the viscosity of the mixture obtained through the process of 'step (1)' is controlled in the range of 400 to 800 cP, and the electrospinning conditions of the 'step (2)' are applied at a voltage of 5 to 30 kV and a radiation amount of 10 to 20 ml. Electrospinning in the range of / h gives a fibrous shape.

Heat treatment of the 'step (3)' is preferably made for 0.5 to 10 hours in the temperature range of 1,500 to 2,000 ℃.

The present invention also provides a porous nano silicon carbide having oxidation resistance at a high temperature produced by the above method.

According to the present invention, a simple and economical method is solved by solving the problems of the conventional method for producing silicon carbide, such as the difficulty of processing conditions, the removal of solvent, the use of pore-forming agents and the like, and the environmental pollution. Porous nano silicon carbide can be prepared.

Porous nano-silicon carbide prepared by the present invention, unlike the prior art does not occur cracks, excellent oxidation resistance and porosity.

Hereinafter, the present invention will be described in detail.

The present invention provides a method for producing porous nano silicon carbide having oxidation resistance at high temperature, and the method for preparing porous nano silicon carbide having oxidation resistance at high temperature according to the present invention comprises: (1) polymer precursor and silicon compound; Mixing; (2) electrospinning the mixture obtained through the process of 'step (1)' into a spherical or fibrous form; (3) heat-treating the result of the electrospinning result obtained through the process of 'step (2)'.

Any polymer precursor may be used as long as the polymer precursor used in the step (1) can be converted into carbon. Specific examples include petroleum pitch, coal pitch, polyimide, polybenzimidazole, polyacrylonitrile, polyaramid, polyaniline, mesophase pitch, furpril alcohol, phenol, cellulose, sucrose, polyvinyl chloride and their It may be selected from the group consisting of a mixture.

The solvent used in the 'step (1)' may be used as long as it dissolves the polymer precursor and the silicon compound. For example, dimethylformamide, chloroform, N-methylpyrrolidone tetrahydro It may be selected from the group consisting of furan, sulfuric acid, nitric acid, acetic acid, hydrochloric acid, ammonia, distilled water and mixtures thereof.

In the mixture obtained through the process of 'step (1)', the molar ratio of carbon (C) and silicon (Si) is preferably 3 to 7: 1. Here, the molar ratio of carbon to silicon refers to the molar ratio of carbon to silicon compound in the polymer precursor. When carbon is mixed less than 3 moles based on 1 mole of silicon, carbon reacts with oxygen contained in the silicon compound to form carbon monoxide (CO) or carbon dioxide (CO ₂ ), so that silicon does not become silicon carbide but silicon There is a problem of remaining in itself. In addition, when more than 7 moles of carbon is mixed based on 1 mole of silicon, the amount of carbon is so large that the amount of carbon remaining instead of silicon carbide is large. That is, silicon may exist in the form of embedded carbon, which is not suitable for the purpose of the present invention. Repeated experiments showed that the molar ratio of carbon (C) and silicon (Si) was selected in the range of 3 to 5: 1 in terms of yield, oxidation resistance, and the like.

The viscosity of the mixture obtained through the process of 'step (1)' is preferably 100 to 800 cP. The mixture obtained through the step (1) is electrospun using an electrospinning apparatus. A schematic electrospinning apparatus is shown in FIG. As shown in FIG. 1, the electrospinning apparatus includes a metering pump 1, a voltage generator 2, a concentrator 3, and a radiator 4. In brief, the operation of the solution is injected into the radiator 4 through the metering pump 1, and the solution radiated through the radiator 4 is focused by the rotating concentrator 3. The voltage generator 2 applies a necessary voltage. That is, the mixture obtained through the 'step (1)' is radiated through the spinner, when the viscosity of the mixture exceeds 800 cP problem that the spinning is blocked by the cohesive force between the polymers do not achieve a smooth spinning Can occur. In addition, when the viscosity of the mixture is less than 100 cP there is a problem that does not have a constant shape due to too low viscosity is not preferred.

The controllable conditions in the electrospinning process of step (2) are largely voltage, radiation dose, distance between the radiator and the concentrator, and the rotation speed of the concentrator. That is, by appropriately controlling the above conditions, it is possible to obtain silicon carbide of various shapes and properties.

The voltage in the electrospinning process is preferably in the range of 5 to 50 kV. If the voltage is lower than the lower limit, the viscosity of the solution may not be overcome, and the problem of unsatisfactory spinning may occur. If the voltage exceeds the upper limit, the fiber phase may be broken due to too strong electrostatic force or difficult to obtain a constant shape. There is a possibility that problems may occur, which is not preferable.

Moreover, it is preferable that a radiation amount is 1-20 ml / h. If the radiation amount is less than the lower limit, the spinning is not possible, or the diameter is so small that the fiber is broken or difficult to obtain a bead of a constant size and shape, if the radiation amount exceeds the upper limit to prepare a nano-size It is not desirable because of difficult problems.

It is preferable that the distance between the radiator and the concentrator is 5 to 50 cm. If the distance between the radiator and the concentrator is less than the lower limit, it is difficult to control the diameter and shape, and it is difficult to manufacture the nano size. If the distance exceeds the upper limit, there is a risk that the spun mixture may not reach the concentrator, and there is a possibility that a change in physical properties may occur until the concentrator is reached, which is not preferable.

It is preferable that the rotational speed of the collector is 10 to 1,000 rpm. If the rotational speed is lower than the lower limit, it is difficult to collect (converge). If the rotational speed exceeds the upper limit, the collected shape is distorted. Not desirable

  Of these four conditions, the main conditions governing the process are voltage and radiation dose. The distance between the radiator and the concentrator and the rotational speed of the concentrator are also important conditions, but they can be regarded as dependent conditions to be adjusted according to the voltage and radiation dose.

By using this point, the shape of the electrospinning result can be controlled by adjusting the viscosity and electrospinning conditions of the mixture. The shape can be largely controlled into a spherical shape and a fiber shape, which will be described in detail as follows.

First, the inventors of the present invention, in order to obtain the result of electrospinning in spherical and fibrous shapes, were found to have the following tendencies. It was confirmed that a spherical shape was obtained when the viscosity of the mixture was low, the voltage was high, the radiation amount was low, and the distance between the emitter and the concentrator was far within the electrospinning conditions described above. On the contrary, it was confirmed that fibrous form was obtained when the viscosity of the mixture was high, the voltage was low, the radiation amount was high, and the distance between the spinning machine and the concentrator was close.

As a result of discovering the above tendency and repeating the experiment, it was possible to specify the conditions for obtaining the spherical shape and the fibrous shape.

First, the viscosity of the mixture obtained through the process of 'step (1)' is adjusted to 100 to 500 cP, and the electrospinning conditions of the 'step (2)' are applied at a voltage of 20 to 50 kV and a radiation amount of 1 to 10 ml /. Electrospinning at h yields spherical complexes.

In addition, the viscosity of the mixture obtained through the process of 'step (1)' is adjusted to 400 to 500 cP, and the electrospinning conditions of the 'step (2)' are applied at a voltage of 5 to 30 kV and a radiation amount of 10 to 20 ml /. When the electrospinning in the state of h can be obtained a fibrous composite.

The overlapping part of the conditions for obtaining the spherical shape and the fibrous shape may be obtained by the spherical shape or the fibrous shape depending on the distance between the radiator and the concentrator and the rotation speed of the concentrator.

Heat treatment of the 'step (3)' is preferably made for 0.5 to 10 hours in the temperature range of 1,500 to 2,000 ℃.

If the heat treatment temperature and the heat treatment time are less than the lower limit, there is a possibility that the carbon-silicon bonding reaction and sintering may not occur sufficiently. It is not preferable because the problem is that the sintered densely blocks the pores and wastes unnecessary energy.

The present invention will be described in more detail with reference to the following Examples.

Example  1: at high temperature Oxidation resistance  Preparation of Spherical Porous Nano Silicon Carbide Having

Coal pitch and silicon dioxide were dissolved in dimethylformaldehyde to prepare precursor solutions at various molar ratios of carbon and silicon. The composition ratio of each component is as follows.

Sample name Coal pitch Silicon dioxide Dimethylformaldehyde Molar ratio (C / Si) 3C / Si 4.5 g 8.0g 90 g 3 4C / Si 6.0 g 8.0g 90 g 4 5C / Si 7.5g 8.0g 90 g 5 6C / Si 9.0 g 8.0g 90 g 6

The precursor solution was electrospun using the electrospinning device shown in FIG.

The conditions of electrospinning were 40 kV, 20 cm distance between the concentrator and the radiator tip (TCD), 5.0 ml / h of radiation, 300 rpm rotation of the concentrator, and 18 gauge needles with a radiator tip (inner diameter 1.27 mm).

The electrospinning result was stabilized at 250 ° C. for 5 hours in an air atmosphere, and then heated under an argon atmosphere at a temperature rising rate of 20 ° C./min, and finally heat treated at 1,600 ° C. for 1 hour.

Through the above process, spherical porous nano silicon carbide having oxidation resistance at high temperature was prepared.

In order to determine the surface characteristics of the silicon carbide obtained above, a scanning electron microscope (SEM) image was taken, and 4C / Si is shown in FIG. 2. As shown in the figure, the silicon carbide was confirmed to be porous and nano-sized spherical.

3 is a graph showing an X-ray diffraction (XRD) of silicon carbide obtained above. It can be confirmed that the prepared sample has the structure of β-SiC. In addition, the crystal size and lattice constant of the diffraction angle of β-SiC (220) were calculated using the XRD data and the Scherrer and Bragg equations, and are shown in the following table.

Sample name Center (2e) FWHM (θ) Crystallite size (nm) Latticeparameter 3C / Si 59.96 0.24 28.7 4.363 4C / Si 59.90 0.24 28.7 4.367 5C / Si 59.94 0.23 29.9 4.365 6C / Si 59.98 0.22 31.3 4.362

Figure 4 shows the results of thermogravimetric analysis (TGA: thermo gravimetric analysis) in the air, it can be confirmed the oxidation resistance at high temperature of the nano-sized porous silicon carbide prepared according to this embodiment. Porous silicon carbides such as 3C / Si and 4C / Si were found to have very high oxidation resistance due to no change in weight up to 1,000 ° C in the air atmosphere. Porous silicon carbides such as 5C / Si and 6C / Si It can confirm that it has oxidation resistance to the comparatively high temperature of about 600 degreeC.

In order to confirm the porosity of the prepared porous silicon carbide, the nitrogen adsorption isotherm at 77K is shown in FIG. 5. 5 it can be confirmed that the porous silicon carbide prepared according to the present example has a high specific surface area and porosity. The porosity derived from the adsorption isotherm is shown in the table below with specific surface area, average pore diameter, BJH total pore volume, and HK micropore volume.

Sample name BET specific surface area
(m ² / g) Average pore diameter
(nm) BJH Firearm Volume
(cm ³ / g) HK micropore volume
(cm ³ / g) 3C / Si 4.5 20.1 0.045 0.003 4C / Si 5.5 23.0 0.066 0.003 5C / Si 93.7 17.3 0.461 0.033 6C / Si 97.1 16.5 0.467 0.033

The pore size distribution of the porous silicon carbide according to the present embodiment obtained by using the information from the adsorption isotherm and the DFT theory is shown in FIG. 6.

Example  2: at high temperature Oxidation resistance  Have Fibrous  Preparation of Porous Nano Silicon Carbide

Polyacrylonitrile and silicon dioxide were dissolved in dimethylformaldehyde to prepare precursor solutions at various carbon and silicon molar ratios. The composition ratio of each component is as follows.

Sample Name Polyacrylonitrile Silicon dioxide Dimethylformaldehyde Molar ratio (C / Si) 3C / Si F 3 g 3.4 g 27 g 3 4C / Si F 3 g 2.5g 27 g 4 5C / Si F 3 g 2.0 g 27 g 5 6C / Si F 3 g 1.7 g 27 g 6 7C / Si F 3 g 1.5 g 27 g 7

The precursor solution was electrospun using an electrospinning device as shown in FIG. 1.

The conditions of electrospinning were a voltage of 20 kV, a distance between the concentrator and the radiator tip (TCD) 20 cm, a radiation dose of 15.0 ml / h, a rotation speed of the concentrator 300 rpm, and a radiator tip 18 gauge needle (inner diameter 1.27 mm).

The electrospinning result was stabilized at 250 ° C. for 5 hours in an air atmosphere, and then heated under an argon atmosphere at a temperature rising rate of 20 ° C./min, and finally heat treated at 1,600 ° C. for 1 hour.

Through the above process, a fibrous porous nano silicon carbide having oxidation resistance at high temperature was prepared.

In order to investigate the surface characteristics of the silicon carbide according to the present embodiment, a scanning electron microscope (SEM) image was taken and double 7C / Si is illustrated in FIG. 7. As shown in the figure it can be confirmed that the porous and nano-sized silicon carbide was formed into a fibrous form.

8 is a graph showing an X-ray diffraction (XRD) of the porous silicon carbide prepared according to the present embodiment, and it was confirmed that the prepared sample had the structure of β-SiC. In addition, the crystal size and lattice constant of the diffraction angle of β-SiC (220) were calculated using the XRD data and the Scherrer and Bragg equations, and are shown in the following table.

Sample Name Center (2e) FWHM (θ) Crystallite size (nm) Lattice parameter 3C / Si F 60.02 0.30 22.9 4.3596 4C / Si F 59.96 0.24 28.7 4.3635 5C / Si F 60.02 0.26 26.5 4.3596 6C / Si F 59.98 0.27 25.5 4.3622 7C / Si F 60.06 0.31 22.2 4.3569

Figure 9 shows the results of thermogravimetric analysis (TGA: thermo gravimetric analysis) in the air atmosphere, it was confirmed that the oxidation resistance at high temperature of the porous silicon carbide prepared by this embodiment. Porous silicon carbide such as 3C / Si F, 4C / Si F, 5C / Si F showed very high oxidation resistance because there was almost no change in weight up to 1,000 ℃ in air atmosphere, and 6C / Si, 7C Porous silicon carbide such as / Si can be confirmed to have oxidation resistance up to a high temperature of about 600 ℃.

In order to confirm the porosity of the porous silicon carbide prepared according to the present embodiment, the nitrogen adsorption isotherm at 77K is shown in FIG. 10. 10, it was confirmed that the porous silicon carbide prepared according to the present example had a high specific surface area and porosity. The porosity derived from the adsorption isotherm is shown in the table below with specific surface area, average pore diameter, BJH total pore volume, and HK micropore volume.

Sample Name BET specific surface area (m ² / g) Average pore diameter (nm) BJH Total Pore Volume (cm ³ / g) HK Micropore Volume (cm ³ / g) 3C / Si F 9.2 90.0 0.055 0.003 4C / Si F 9.8 66.3 0.069 0.003 5C / Si F 13.4 20.4 0.037 0.002 6C / Si F 34.1 37.7 0.144 0.029 7C / Si F 42.8 21.1 0.157 0.008

In addition, the pore size distribution of the porous silicon carbide according to the present embodiment obtained using the information from the adsorption isotherm and the DFT theory is shown in FIG. 11.

Although the present invention has been described with reference to the above-described embodiments and the accompanying drawings, different embodiments may be configured without departing from the spirit and scope of the invention. Therefore, the scope of the present invention is defined by the appended claims and equivalents thereof, and is not limited by the specific embodiments described herein.

1 is a schematic view showing an electrospinning apparatus.

FIG. 2 is an SEM image of 20,000 magnification of 4C / Si in silicon carbide prepared by Example 1 of the present invention. FIG.

3 is XRD lattice analysis data of silicon carbide prepared according to Example 1 of the present invention.

4 is TGA analysis data in an air atmosphere of silicon carbide prepared according to Example 1 of the present invention.

5 is a nitrogen adsorption and desorption isotherm at 77K of silicon carbide prepared by Example 1 of the present invention.

6 is a pore size analysis result of silicon carbide prepared according to Example 1 of the present invention.

7 is an SEM image of 5,000 magnification of 7C / Si F in silicon carbide prepared according to Example 2 of the present invention.

8 is XRD lattice analysis data of silicon carbide prepared according to Example 2 of the present invention.

9 is TGA analysis data in an air atmosphere of silicon carbide prepared according to Example 2 of the present invention.

10 is a nitrogen adsorption and desorption isotherm at 77K of silicon carbide prepared by Example 2 of the present invention.

11 is a pore size analysis result of silicon carbide prepared by Example 2 of the present invention.

Claims (10)

(1) mixing a polymer precursor and a silicon compound with a solvent; (2) electrospinning the mixture obtained through the process of 'step (1)' into a spherical or fibrous form; And (3) A method of producing porous nanosilicon carbide having oxidation resistance at high temperature comprising the step of heat-treating the result of electrospinning obtained through the process of 'step (2)'. The method of claim 1, The polymer precursor used in the 'step (1)' is petroleum pitch, coal pitch, polyimide, polybenzimidazole, polyacrylonitrile, polyaramid, polyaniline, mesophase pitch, furryl alcohol, phenol, cellulose And sucrose, polyvinyl chloride, and a mixture thereof. A method for producing porous nano silicon carbide having oxidation resistance at high temperature, characterized in that the above-mentioned. The method of claim 1, The solvent used in the 'step (1)' is selected from the group consisting of dimethylformamide, chloroform, N-methylpyrrolidone tetrahydrofuran, sulfuric acid, nitric acid, acetic acid, hydrochloric acid, ammonia, distilled water and mixtures thereof Method for producing a porous nano silicon carbide having oxidation resistance at a high temperature, characterized in that. The method of claim 1, Method for producing porous nano silicon carbide having oxidation resistance at high temperature, characterized in that the molar ratio of carbon (C) and silicon (Si) in the mixture obtained through the process of 'step (1)' is 3 to 7: 1. The method of claim 1, Method for producing a porous nano silicon carbide having oxidation resistance at high temperature, characterized in that the viscosity of the mixture obtained through the process of 'step (1)' is 100 to 800 cP. The method of claim 1, Electrospinning conditions in the electrospinning process of the 'step (2)', Method for producing porous nano silicon carbide having oxidation resistance at high temperature, characterized in that the voltage of 5 to 50kV, radiation amount 1 to 20 ml / h. The method of claim 1, The viscosity of the mixture obtained through the process of 'step (1)' is 100 to 500 cP, Electroporation having a high oxidation resistance at high temperature, characterized in that the electrospinning conditions in the step (2) of the electrospinning to obtain a spherical electrospun silicon carbide at a voltage of 20 to 50kV, radiation amount 1 to 10 ml / h Method for producing nano silicon carbide. The method of claim 1, The viscosity of the mixture obtained through the process of 'step (1)' is 400 to 800 cP, Porous having oxidation resistance at high temperature, characterized in that the electrospinning conditions in the step (2) of the electrospinning to obtain a fibrous electrospun silicon carbide at a voltage of 5 to 30kV, radiation amount 10 to 20 ml / h Method for producing nano silicon carbide. The method of claim 1, The step of heat treatment of the 'step (3)', the method of producing porous nano silicon carbide having oxidation resistance at high temperature, characterized in that made for 0.5 to 10 hours at a temperature range of 1,500 to 2,000 ℃. A porous nano silicon carbide having oxidation resistance at a high temperature produced by the method according to any one of claims 1 to 9.

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