KR100624094B1 - The method of producing carbon fiber reinforced ceramic matrix composites - Google Patents

Abstract

The present invention relates to a method for producing a carbon fiber-reinforced ceramic composite material, and a method for manufacturing a carbon fiber-reinforced ceramic composite material according to the present invention comprises the steps of: preparing a carbon fiber-reinforced resin composite molded from a mixture of carbon fibers and a carbon- Wow; Preparing carbon fiber reinforced carbon composites by depositing pyrolytic carbon in a rapid thermal gradient chemical vapor deposition process while heating the carbon fiber reinforced resin composite at a high temperature to increase the deposition rate from the inside to the outside; And infiltrating the liquid silicon into the pores of the carbon fiber-reinforced carbon composite. The method of manufacturing a carbon fiber-reinforced ceramic composite according to the present invention has an effect of improving the physical properties of a carbon fiber-reinforced ceramic composite material and is capable of depositing a pyrolytic carbon layer at a deposition rate of 5 to 10 times or more as compared with all conventional chemical vapor- So that it has a remarkably improved effect in terms of the manufacturing process, the manufacturing time and the manufacturing cost.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a carbon fiber-

1 is a block diagram showing a method of manufacturing a carbon fiber-reinforced ceramic composite using carbon fiber and carbon fiber mixture according to the present invention.

FIG. 2 is a block diagram illustrating a method of manufacturing a carbon fiber-reinforced ceramic composite using the carbon felt preform according to the present invention.

3 is a microstructure photograph of the carbon fiber-reinforced ceramic composite according to the present invention.

4 is a conceptual diagram showing a rapid thermal gradient chemical vapor deposition method according to the present invention.

Description of the Related Art [0002]

101 ... carbon fiber

102 ... pyrolysis carbon

103 ... silicon carbide

104 ... Residual silicon

The present invention relates to a method of manufacturing a carbon fiber-reinforced ceramic composite material having excellent mechanical strength at high temperature and excellent corrosion resistance, heat resistance, and friction / wear characteristics in a harsh environment such as thermal and chemical erosion.

Fiber-reinforced ceramic composites are lightweight and have excellent mechanical and thermal properties at high temperatures. With these properties, the fiber-reinforced ceramic composites can be applied to friction and wear materials such as brake discs and pads for aircraft and land vehicles, ceramic engines requiring high mechanical strength, corrosion resistance and heat resistance, and ultra-high temperature resistant materials for rocket nozzle parts. . Fiber-reinforced ceramic composites have been studied to overcome the disadvantages of brittle fracture of ceramic materials (monolithic ceramics). The pores of preforms made of carbon fiber or silicon carbide fiber are heat-decomposed by heat-resistant materials such as carbon, silicon carbide or boron nitride .

Until now, fiber-reinforced ceramic composites have been manufactured in various manufacturing processes, but most of them cause damage to the fiber due to mechanical or thermal impact during the manufacturing process. To solve this problem, ceramic composites deposit a precursor of gaseous state in a low density porous fiber preform and pyrolyze it to deposit a ceramic matrix. This process is called chemical vapor infiltration (CVD), and this fabrication process solves the problems of fiber damage caused by the fabrication of conventional ceramic composites by depositing the matrix at low temperature and pressure.

However, since these processes use expensive raw materials and manufacturing equipment, and the manufacturing process is complicated and requires a process time of several hundred hours or more, its application fields are very limited to advanced industrial fields such as space and aviation.

Unlike a chemical vapor deposition process using a gaseous raw material gas, a process of producing a carbon fiber-reinforced ceramic composite by impregnating a liquid silicon with a porous carbon preform has been developed.

Walter Krenkel et al. Prepared carbon fiber-reinforced carbon composites by high temperature heat treatment process after forming the cut carbon fiber, liquid phenol and carbon powder mixture under high temperature and high pressure conditions in US 6,308,808, US 6,358,565 and US 5,942,064. The carbon fiber-reinforced carbon composite thus obtained was infiltrated with liquid silicon to apply the carbon fiber reinforced ceramic composite material to the brake disk of the land vehicle and the heat resistant material in the space and aviation field.

However, the carbon fiber reinforced resin composite prepared by mixing the liquid carbon precursor as described above is more efficient than the chemical vapor infiltration process in terms of production cost, but it is difficult to form a uniform carbon fiber protective layer. Therefore, It is difficult to prevent the reaction of carbon fibers, which drastically reduced the mechanical properties of carbon fiber reinforced ceramic composites. In order to solve such problems, Korean Patent Application No. 1999-7008146, US Pat. Nos. 6079525, 6030913 and 6231791 repetitively impregnate a liquid organic binder or change the composition of a mixture to prepare a carbon fiber reinforced ceramic composite However, it has not been possible to prevent deterioration of mechanical properties due to carbon fiber erosion and to improve the high-temperature friction / wear characteristics.

As another process, US Patent No. 6221475 and Korean Patent Application No. 1999-7003211 disclose a process for producing a carbon fiber preform by isothermal / isobaric chemical vapor infiltration (ICVI) Then, the carbon precursor was subjected to a densification process by a liquid impregnation method to prepare a carbon fiber reinforced ceramic composite. Although this process has achieved excellent performance improvement in terms of fiber protection, it is difficult to bond different carbon fiber reinforced ceramic composites to one structure, making it difficult to manufacture a complex shaped carbon fiber reinforced ceramic composite. In particular, the manufacturing process is complicated and requires a manufacturing time of several hundred hours or more, resulting in an increase in manufacturing cost.

Comprehensively examining the problems related to the manufacturing technology of the carbon fiber reinforced ceramic composites so far, it has been found that, in most cases, the manufacturing cost of the carbon fiber reinforced carbon composites used for manufacturing the carbon fiber reinforced ceramic composites is increased, It can be seen that there is a problem. For example, conventional chemical vapor deposition processes have excellent properties as a fiber protective layer, but are not suitable for the production of carbon fiber reinforced carbon composites because of expensive raw materials and difficulties in the manufacturing process. In addition, when carbon fiber reinforced resin composites are prepared by using the impregnation process of an organic binder containing a carbon component, repetitive impregnation process is required and the effect of the fiber protection is reduced.

It is an object of the present invention to improve the thermal and mechanical properties of carbon fiber reinforced ceramic composites by improving starting materials and methods for producing carbon fiber reinforced carbon composites necessary for manufacturing carbon fiber reinforced ceramic composites. And to provide a method for manufacturing a carbon fiber-reinforced ceramic composite material which solves the above problems due to an expensive production cost and process.

In order to solve the above problems, the present inventors have developed a carbon fiber-reinforced carbon composite material having a uniform fiber protective layer at a low cost and at a low cost by using a carbon fiber preform, a sandwich structure or a carbon fiber mixture as a starting material, The present invention is to provide a method for manufacturing a carbon fiber-reinforced ceramic composite by applying a rapid thermal gradient chemical vapor infiltration process, and using a liquid silicon infiltration process.

In order to accomplish the above object, the present invention provides a method for producing a carbon fiber-reinforced ceramic composite (C _f / C-SiC) according to the present invention comprises the steps of: preparing a carbon fiber reinforced resin composite molded from a mixture of carbon fibers and a carbon- Wow; Preparing carbon fiber reinforced carbon composites by depositing pyrolytic carbon in a rapid thermal gradient chemical vapor deposition process while heating the carbon fiber reinforced resin composite at a high temperature to increase the deposition rate from the inside to the outside; And infiltrating the liquid silicon into the pores of the carbon fiber-reinforced carbon composite.

Preferably, the mixture contains 10 to 60 wt% of the carbon fibers and 30 to 60 wt% of the carbon-containing polymer precursor.

Also preferably, the mixture contains 30 wt% or less of silicon carbide powder and 30 wt% or less of carbon powder.

Preferably, the carbon fiber-reinforced resin composite is characterized in that the mixture and the carbon fabric are alternately laminated.

Also, preferably, the formed body is formed with a primary surface layer for blocking the reaction between carbon fibers and silicon by the mixture mixed in the mixing process, and the primary surface layer is chemically reacted with the liquid silicon in the step of penetrating the liquid silicon And is formed of a ceramic base layer composed of silicon carbide and silicon.

Preferably, the shaped body is heat-treated at a temperature of 900 to 2200 ° C in an inert gas atmosphere, and then a pyrolytic carbon base layer, which is a secondary surface layer, is deposited on the first surface layer in the step of depositing by the rapid thermal gradient chemical vapor deposition .

Preferably, the thermal decomposition reaction is carried out at a pyrolysis reaction temperature of 700 to 1200 ° C. and a reaction pressure of 188 to 1130 torr using hydrocarbon gas in the step of depositing by the rapid thermal gradient chemical vapor deposition process.

Preferably, in the step of depositing by the rapid thermal gradient chemical vapor deposition process, the deposition region is divided into at least a plurality of regions from the inside to the outside, and the regions are deposited at different rates in the respective regions.

Also preferably, the deposition region is deposited from the inside to the outside at a deposition rate ranging from 0.5 to 3.0 mm / hr.

Preferably, the carbon fiber-reinforced carbon composite material has an apparent density of 1.0 to 1.7 g / cm 3 and 5 to 30% of open pores used as a penetration path of the liquid silicon.

Preferably, the step of impregnating the liquid silicon is performed by laminating the carbon fiber-reinforced carbon composite on a silicon powder, heating the interior of the reactor to not more than 100 torr, and then heating the silicon fiber to a temperature of 1410 ° C or higher, And induces a chemical reaction with a plurality of carbon layers.

According to another aspect of the present invention, there is provided a method of manufacturing a carbon fiber-reinforced ceramic composite comprising: preparing a carbon felt preform; Depositing the carbon felt preform in a rapid thermal gradient chemical vapor deposition process at a rapid deposition rate from the inside to the outside to produce a carbon fiber reinforced carbon composite; And infiltrating the liquid silicon into the pores of the carbon fiber-reinforced carbon composite.

Preferably, the carbon felt preform is one of carbon fiber such as oxyphene, pen, rayon, and pitch.

Preferably, the carbon felt preform has quasi-isotropic properties such as 0 ° / + 60 ° / -60 ° in the lamination of the mat, and carbon fibers of 10 mm or less in the Z axis are reinforced.

Preferably, the pyrolytic carbon layer having a thickness of 5 to 100 μm is deposited on the carbon felt preform by the rapid thermal gradient chemical vapor deposition process.

Also preferably, the step of infiltrating the liquid silicon is characterized in that the carbon fiber reinforced carbon composite is impregnated with liquid silicon to reinforce the carbon fibers in the X, Y, and Z axes.

Preferably, the thermal decomposition reaction is carried out at a pyrolysis reaction temperature of 700 to 1200 ° C. and a reaction pressure of 188 to 1130 torr using hydrocarbon gas in the step of depositing by the rapid thermal gradient chemical vapor deposition process.

Preferably, in the step of depositing by the rapid thermal gradient chemical vapor deposition process, the deposition region is divided into at least a plurality of regions from the inside to the outside, and the regions are deposited at different rates in the respective regions.

Also preferably, the deposition region is deposited from the inside to the outside at a deposition rate ranging from 0.5 to 3.0 mm / hr.

Preferably, the carbon fiber-reinforced carbon composite material has an apparent density of 1.0 to 1.7 g / cm 3 and 5 to 30% of open pores used as a penetration path of the liquid silicon.

Preferably, the step of impregnating the liquid silicon is performed by laminating the carbon fiber-reinforced carbon composite on a silicon powder, maintaining the inside of the reactor at 100 torr or less, and then heating the liquid silicon at a temperature of 1410 ° C or higher, And permeates into the felt preform and simultaneously induces a chemical reaction with the plurality of carbon layers.

Hereinafter, a method of manufacturing a carbon fiber-reinforced ceramic composite according to the present invention will be described. The composition and the production method of each mixture in the following examples may be modified in various ways to modify a part of the constitution. However, it should be understood that the modified embodiments basically belong to the technical scope of the present invention if they include the technical elements claimed by the present invention.

First, carbon fiber preforms reinforced with carbon fibers in the directions of X, Y and Z axes are used, or carbon fibers having a length of 0.3 to 150 mm, carbon-containing polymer precursors, silicon carbide A carbon fiber reinforced resin composite (CFRP) composed of the above-mentioned mixture may be used, or a sandwich structure produced by alternately laminating a mixture of carbon powder and graphite powder and carbon fabrics may be used.

The prepared starting material is prepared by depositing a pyrolytic carbon layer by a rapid thermal gradient chemical vapor deposition process as described below to prepare a porous carbon fiber-reinforced carbon composite material. The liquid silicon is permeated into open pores in the carbon fiber- Fiber reinforced ceramic composite. The carbon fiber-reinforced ceramic composite has a bulk density of 2.2 g / cm 3 or more, an apparent porosity of 1% or less, a bending strength of 100 MPa or more, and a thermal conductivity of 35 W / mK or more.

The method of manufacturing a carbon fiber-reinforced ceramic composite according to the present invention can be divided into two processes according to the starting materials as shown in FIGS. 1 and 2. FIG.

The process shown in FIG. 1 is a process for producing a carbon fiber reinforced resin composite using a mixture of carbon fibers, a carbon-containing polymer precursor, a silicon carbide powder, and a graphite powder cut in a size of 0.3 to 150 mm and a carbon fabric.

The carbon fiber reinforced resin composites are prepared by homogenizing the carbon fibers cut into 0.3 ~ 150 mm size with carbon-containing polymer precursor, silicon carbide powder and graphite powder in distilled water and dispersing and mixing.

And the mixture is composed of carbon-containing polymer precursor, silicon carbide powder and graphite powder on the surface of the carbon fiber to form a primary surface layer. The mixture composition is 10 to 60 wt% of carbon fiber and 30 to 60 wt% of carbon-containing liquid precursor. And silicon carbide powder and carbon powder are optionally included. 0 to 30 wt% of silicon carbide powder and 0 to 30 wt% of carbon powder (S101) (S102)

The thus-prepared mixture is alternately laminated with the carbon fabric to form a sandwich green body (S110). Carbon fabrics are available in plain weave, weave weave, and twill weave. Here, another method of producing a molded body can be produced by laminating only a mixture without alternately stacking carbon fabrics.

The molded body thus prepared is charged into a molding mold, and a pressure of 1 to 20 MPa and a temperature of 80 to 250 캜 are simultaneously applied to produce a carbon fiber reinforced resin composite. The produced carbon fiber reinforced resin composite has an apparent density of 1.2 to 1.6 g / cm3 and an apparent porosity of 1 to 20% (S110) (S120) (S130)

The method of manufacturing a carbon fiber reinforced resin composite as described above can be applied to other embodiments by applying the technical contents described in Korean Patent Application No. 1995-0069130 and Korean Patent Application No. 1997-0023344 filed by the present applicant.

Next, in the step of depositing the carbon fiber-reinforced resin composite by the rapid thermal gradient chemical vapor deposition process (S140), the produced carbon fiber-reinforced resin composite is heat-treated at a temperature of 700 to 2200 ° C under an inert gas atmosphere and then subjected to a rapid thermal gradient chemical vapor deposition Carbon fiber-reinforced carbon composite.

Specifically, the rapid thermal gradient chemical vapor deposition process of the present invention is for producing a dense carbon fiber-reinforced carbon composite material having a density of 1.3 g / cm 3 or more. The rapid thermal gradient chemical vapor deposition process includes at least three regions And the deposition rate is controlled in each section so that deposition is performed more rapidly. At this time, the deposition rate control is performed by moving the thermocouple provided inside the chemical vapor deposition apparatus from the inside to the outside of the formed body at a gradually higher speed.

That is, as shown in FIG. 4, a carbon fiber reinforced resin composite 500 is installed inside the reactor 300, and a heating element 400 is installed at the center. And supplying hydrocarbon gas to the process gas. The deposition rate control is performed using a thermocouple (not shown) as described above, and the deposition is performed from the inside to the outside.

The deposition rate arrows shown in the figure indicate that the deposition rate is slow and the deposition rate is long. And the T1 portion is high temperature and the T2 portion is low temperature, which indicates that a troposphere is induced.

At this time, the deposition rate is 0.5 to 3.0 mm / hr. For example, the inside is divided into the inside, the middle, and the outside, and then the inside is deposited at 1.0 mm / hr, the middle is deposited at 1.5 mm / hr, and the outside is deposited at 2.0 mm / hr, . In this case, since the deposition rate is slowed inside, the deposition is relatively delayed from the inside of the molded body.

By controlling the deposition rate in this manner, it is possible to control the deposition rate at a high rate by controlling all of the existing methods such as isothermal / isostatic chemical vapor deposition, pressure gradient chemical vapor deposition, and conventional constant velocity thermal gradient chemical vapor deposition The manufacturing process and the manufacturing cost can be improved in comparison with the chemical vapor infiltration process.

This rapid thermal gradient chemical vapor deposition process is faster and more densified than the thermal gradient chemical vapor deposition process of Korean Patent No. 0198154, which is a patent right of the present applicant, at a deposition rate of 5 to 10 times or more, It is possible to form a pyrolytic carbon layer having a thickness of about 10 탆.

The pyrolytic carbon layer formed at this time acts as a reaction layer which reacts with the liquid silicon to form a silicon carbide matrix phase in the liquid silicon impregnation process.

The carbon fiber reinforced resin composite produced by the rapid thermal gradient chemical vapor deposition process of the present invention has an apparent density of 1.0 to 1.7 g / cm 3 and an apparent porosity value of 5 to 30%.

Next, the liquid silicon infiltration process places the carbon fiber-reinforced carbon composite produced by the rapid thermal gradient chemical vapor deposition process on the silicon powder in the range of 1 to 10 mm particle size.

The process conditions are heated to a temperature of 1410 ° C or higher, which is the melting point of silicon in a vacuum atmosphere. The silicon melted at a high temperature of 1410 ° C or higher fills most of the pores within a few minutes due to the capillary force of the pores present in the carbon fiber-reinforced carbon composite material, and at the same time, reacts with the carbon reaction layer on the carbon fiber to synthesize silicon carbide . The finally produced carbon fiber-reinforced ceramic composite body is composed of 30 to 60 wt% of carbon, 35 to 60 wt% of silicon carbide, and 5 wt% or less of unreacted silicon.

Next, as shown in FIG. 2, a carbon fiber-reinforced ceramic composite body can be manufactured using a molded body made of a carbon felt preform as a starting material.

First, a carbon felt preform reinforced in three axial directions of X, Y and Z is manufactured (S200). Specifically, a carbon fiber such as oxyphene, pen, rayon and pitch is wound around a mandrel to form a one- And the carbon mat produced by this method is laminated. The lamination method is alternately laminated with quasi-isotropy such as 0 ° / + 60 ° / -60 °.

After stacking at least two layers, each layer is reinforced in the Z-axis direction by punching using needles, and the above process is repeated to produce a felt preform having a thickness of 30 mm or more.

The fiber volume of the felt preform is about 10 to 55%, the thickness of one layer is about 0.1 mm or less, the fiber length of the Z-axis is 10 mm or less, and the fiber ratio is about 10%. And a needle of 15penetration / cm3 density can be used for the Z axis.

Then, heat treatment is performed in a vacuum atmosphere at 1700 ° C or more to remove impurities of the carbon felt preform. Regarding the method of manufacturing such a carbon felt preform, reference is made to the embodiments of U.S. Patent Application Nos. 10-180778 and 27788 filed by the present applicant.

Next, a carbon fiber-reinforced carbon composite is prepared (S210) by using a rapid thermal gradient chemical vapor deposition process. The carbon fiber-reinforced carbon composite is manufactured by using the rapid thermal gradient chemical vapor deposition process mentioned in the first process, (S220).

Then, a carbon fiber reinforced ceramic composite is manufactured by using a liquid silicon infiltration process. This liquid-phase silicon impregnation process is applied in the same manner as the first process embodiment described above.

Hereinafter, a preferred embodiment of the above method will be described.

≪ Example 1 >

A mixture of 30 wt% carbon fiber cut to a size of 30 mm, 40 wt% of a phenolic resin, 5 wt% of a carbon powder, and 5 wt% of a silicon carbide powder was alternately laminated with 20 wt% The prepared molded body was put into a molding mold and cured at a pressure of 2 MPa for 10 minutes under pressure to prepare a carbon fiber reinforced resin composite.

The above carbon fiber-reinforced resin composite was heat-treated at a high temperature in an inert gas atmosphere. And carbon fiber reinforced carbon composites were prepared by depositing pyrolysis carbon under rapid thermal gradient chemical vapor deposition process conditions.

The carbon fiber-reinforced carbon composite thus prepared was laminated on a silicon powder, and heated to a temperature of 1550 ° C in a vacuum atmosphere to impregnate the liquid silicon to prepare a carbon fiber-reinforced carbon-ceramic composite. Table 1 shows the physical properties of the carbon fiber-reinforced ceramic composite thus produced.

≪ Example 2 >

A mixture of 55 wt% of carbon fiber cut to a size of 30 mm, 35 wt% of a phenol resin, 5 wt% of a carbon powder, and 5 wt% of a silicon carbide powder was produced. In Example 2, alternate lamination using a carbon fabric was not performed. The prepared molded body was put into a molding mold and cured at a pressure of 2 MPa for 10 minutes under pressure to prepare a carbon fiber reinforced resin composite.

The above carbon fiber-reinforced resin composite was heat-treated at a high temperature in an inert gas atmosphere. And carbon fiber reinforced carbon composites were prepared by depositing pyrolysis carbon under rapid thermal gradient chemical vapor deposition process conditions.

The carbon fiber-reinforced carbon composite thus prepared was laminated on a silicon powder, and heated to a temperature of 1550 ° C in a vacuum atmosphere to impregnate the liquid silicon to prepare a carbon fiber-reinforced carbon-ceramic composite. Table 1 shows the physical properties of the carbon fiber-reinforced ceramic composite thus produced.

≪ Example 3 >

320K oxyphene fiber was wound around a mandrel to prepare a one-direction carbon mat, and the carbon mat produced by the above method was laminated. The lamination method was alternately laminated by the method of 0 ° / + 60 ° / -60 °.

At least two layers were laminated and punched using needles to reinforce each layer in the Z axis direction. The above process was repeated to prepare a 30 mm thick preform. The oxyphene fiber volume fraction of the preform was about 45%, the thickness of one layer was about 0.9 mm, and the fiber ratio of the z axis was about 10%.

The preform thus prepared was heat-treated at 1700 ° C in a vacuum atmosphere to remove impurities.

The carbon fiber reinforced carbon composites were prepared by depositing pyrolytic carbon under the conditions of rapid thermal gradient chemical vapor deposition.

The carbon fiber-reinforced carbon composite thus prepared was laminated on a silicon powder, and heated to a temperature of 1550 ° C in a vacuum atmosphere to impregnate the liquid silicon to prepare a carbon fiber-reinforced carbon-ceramic composite. Table 1 shows the physical properties of the carbon fiber-reinforced ceramic composite thus produced.

≪ Comparative Example 1 &

54 wt% of the carbon fiber cut to a size of 130 mm was mixed with 36 wt% of phenol resin and 10 wt% of carbon powder to prepare a mixture, and the mixture was put into a molding mold and cured at the same pressure with 3 MPa pressure to prepare a carbon fiber reinforced resin composite.

The above carbon fiber-reinforced resin composite was heat-treated at 900 캜 under an inert gas atmosphere to prepare a carbon fiber-reinforced resin composite. The carbon fiber-reinforced resin composite thus prepared was laminated on silicon powder, heated to a temperature of 1600 캜 in a vacuum atmosphere, and impregnated with liquid silicon to prepare a carbon fiber-reinforced carbon ceramic composite body. Table 1 shows the physical properties of the carbon fiber-reinforced ceramic composite thus produced.

Psalter Apparent density Apparent porosity Flexural strength Thermal conductivity Coefficient of friction (g / cm3) (%) (MPa) W / mK Example 1 2.3 0.5 125 40 0.45 Example 2 2.4 0.3 120 42 0.45 Example 3 2.3 0.7 140 40 0.43 Comparative Example 1 2.1 0.9 80 35 0.40

The carbon fiber-reinforced carbon composite material produced by the rapid thermal gradient chemical vapor deposition process has a uniformly deposited pyrolytic carbon layer, and the pyrolytic carbon layer Is synthesized as silicon carbide by reacting with silicon in the liquid silicon impregnation process. The pyrolytic carbon layer serves not only as a fiber protective layer which prevents the carbon fiber erosion which is the most problem in the liquid silicon impregnation process, Has excellent properties as a reaction layer and also forms a new interface between the carbon fiber and the silicon carbide base so as to improve the mechanical properties of the carbon fiber reinforced ceramic composite.

As shown in FIG. 3, the fine structure of the carbon fiber-reinforced ceramic composite produced according to the method of the present invention is such that the dark gray portion around the carbon fiber is composed of the pyrolytic carbon layer 102 and the light gray portion is the silicon carbide layer 103 ) And the brightest part is the residual silicon layer (104). It can be seen that the carbon fiber is hardly eroded by the pyrolytic carbon layer around the carbon fiber and the silicon carbide is synthesized around the pyrolytic carbon layer.

In the present invention, the rapid thermal gradient chemical vapor deposition process is performed at a deposition rate of 10 times or more as compared with a conventional chemical vapor deposition process, and a deposition rate of 5 times or more as compared with a conventional thermal gradient chemical vapor deposition process It is possible to reduce the manufacturing cost of the carbon fiber-reinforced carbon composite material.

In addition, it is possible to produce a carbon fiber-reinforced resin composite in a single step without repeated densification steps as in the case of a carbon fiber reinforced resin composite manufacturing process using a carbon-containing liquid precursor, and a rapid thermal gradient chemical vapor phase- The combination of the silicon impregnation process simplifies the manufacturing process of the carbon fiber reinforced ceramic composite material and significantly reduces the manufacturing cost, so that it is possible to apply the carbon fiber reinforced ceramic composite material in various fields.

In addition, the molded bodies prepared by mixing carbon fibers having a size of 0.3 to 150 mm with a carbon-containing polymer precursor, silicon carbide powder and carbon powder and alternately laminated or mixed with a carbon fabric are homogeneous in dispersion and mixing, And has excellent properties in forming a primary surface layer. Further, since the shrinkage hardly occurs during the high-temperature heat treatment at 1000 占 폚 or more, there is no change in the dimension, and the cost required for the dimension and shape processing can be greatly reduced.

The carbon fiber-reinforced ceramic composite according to the present invention has the effect of improving the physical properties of the carbon fiber-reinforced ceramic composite material. The carbon fiber-reinforced ceramic composite material according to the present invention has the effect of improving the physical properties of the carbon fiber- It is possible to achieve a remarkably improved effect in terms of the manufacturing process, the manufacturing time, and the manufacturing cost.

Claims (21)

Producing a carbon fiber-reinforced resin composite molded from a mixture containing carbon fibers and a carbon-containing polymer precursor; The carbon fiber-reinforced resin composite is heat-treated at a temperature of 700 to 2200 ° C to deposit pyrolytic carbon in a rapid thermal gradient chemical vapor deposition process while increasing the deposition rate from the inside to the outside of the heat-treated carbon fiber- Reinforced carbon composite; Wherein the step of penetrating the liquid silicon into the pores of the carbon fiber-reinforced carbon composite material is performed. The method of claim 1, wherein the mixture contains 10 to 60 wt% of the carbon fibers and 30 to 60 wt% of the carbon-containing polymer precursor. 3. The method of claim 2, wherein the mixture further comprises at least one of silicon carbide powder and carbon powder. The method according to claim 2 or 3, wherein the carbon fiber-reinforced resin composite comprises the mixture and the carbon fabric alternately laminated. The method according to claim 4, wherein the formed body is formed with a primary surface layer that prevents reaction between carbon fibers and silicon by the mixture mixed in the mixing process, and wherein the primary surface layer is a mixture of the liquid silicon And forming a ceramic base layer composed of silicon carbide and silicon. The method according to claim 1, wherein the formed body is heat-treated at a temperature of 900 to 2200 캜 under an inert gas atmosphere, and then the pyrolytic carbon base layer, which is a secondary surface layer, is deposited on the primary surface layer in the deposition step by the rapid thermal gradient chemical vapor deposition Wherein the carbon fiber-reinforced ceramic composite is produced by a method comprising the steps of: The carbon fiber reinforced ceramic composite material manufacturing method according to claim 1, wherein the carbon nanofibers are formed by using a hydrocarbon gas at a pyrolysis reaction temperature of 700 to 1200 ° C. and a reaction pressure of 188 to 1130 torr in the step of depositing by the rapid thermal gradient chemical vapor deposition process. Way. The method according to claim 1, wherein in the step of depositing by the rapid thermal gradient chemical vapor deposition process, the deposition region is divided into at least a plurality of regions from the inside to the outside, and the regions are vapor- Lt; / RTI > 2. The method of claim 1, wherein the deposition area is deposited from the inside to the outside in a deposition rate range of 0.5 to 3.0 mm / hr. The method of claim 1, wherein the carbon fiber-reinforced carbon composite material has an apparent density of 1.0 to 1.7 g / cm 3 and 5 to 30% of open pores used as a penetration path of the liquid silicon. . The method of claim 1, wherein the step of impregnating the liquid silicon comprises: laminating the carbon fiber-reinforced carbon composite on a silicon powder; maintaining the inside of the reactor at 100 torr or less; Is introduced into the preform and a chemical reaction with the plurality of carbon layers is induced. Producing a carbon felt preform; Depositing the carbon felt preform in a rapid thermal gradient chemical vapor deposition process at a rapid deposition rate from the inside to the outside to produce a carbon fiber reinforced carbon composite; Wherein the step of penetrating the liquid silicon into the pores of the carbon fiber-reinforced carbon composite material is performed. 13. The method of claim 12, wherein the carbon felt preform is one of carbon fiber such as oxyphene, pen, rayon, and pitch. 13. The carbon fiber preform as set forth in claim 12, wherein the carbon felt preform has quasi-isotropic properties such as 0 ° / + 60 ° / -60 ° lamination of the mat, and carbon fibers of 10 mm or less in the Z- Ceramic composite. 13. The method of claim 12, wherein a pyrolytic carbon layer having a thickness of 5 to 100 mu m is deposited on the carbon felt preform by the rapid thermal gradient chemical vapor deposition process. 13. The method of manufacturing a carbon fiber-reinforced ceramic composite material according to claim 12, wherein the step of impregnating the liquid silicon includes impregnating the carbon fiber-reinforced carbon composite with liquid silicon to reinforce the carbon fibers in the X, Y, and Z axes . [12] The method of claim 12, wherein hydrocarbon gas is used in the step of depositing by the rapid thermal gradient chemical vapor deposition, and the pyrolysis reaction temperature is 700 to 1200 DEG C and the reaction pressure is 188 to 1130 torr. Way. 13. The method of claim 12, wherein, in the step of depositing by the rapid thermal gradient chemical vapor deposition process, the deposition region is divided into at least a plurality of regions from the inside to the outside, Lt; / RTI > 13. The method of claim 12, wherein the deposition area is deposited from the inside to the outside in a deposition rate range of 0.5 to 3.0 mm / hr. 13. The method of claim 12, wherein the carbon fiber-reinforced carbon composite material has an apparent density of 1.0 to 1.7 g / cm 3 and an open pore size of 5 to 30% used as a penetration path of the liquid silicon. . 13. The method of claim 12, wherein the step of infiltrating the liquid silicon comprises: laminating the carbon fiber-reinforced carbon composite on a silicon powder, maintaining the inside of the reactor at 100 torr or less, Wherein the carbon fiber reinforced ceramic material is impregnated into the carbon felt preform and a chemical reaction is induced with a plurality of carbon layers.

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