KR20050113090A - The method of producing carbon fiber reinforced ceramic matrix composites - Google Patents

Abstract

The present invention relates to a method of manufacturing a carbon fiber reinforced ceramic composite, the method of manufacturing a carbon fiber reinforced ceramic composite according to the present invention comprises the steps of preparing a carbon fiber reinforced resin composite molded into a mixture of carbon fiber and a carbon-containing polymer precursor Wow; Manufacturing a carbon fiber reinforced carbon composite by depositing pyrolytic carbon by a rapid thermal gradient chemical vapor permeation process while increasing the deposition rate from the inside to the outside by high temperature heat treatment of the carbon fiber reinforced resin composite; It characterized in that the step of penetrating 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 the carbon fiber reinforced ceramic composite, and deposits a pyrolytic carbon layer at a deposition rate of 5 to 10 times or more than all conventional chemical vapor penetration processes. This greatly improves the manufacturing process, manufacturing time and manufacturing cost.

Description

The method of producing carbon fiber reinforced ceramic matrix composites

The present invention relates to a method for producing a carbon fiber reinforced ceramic composite having excellent mechanical strength at high temperatures and having excellent corrosion resistance, heat resistance, and friction and abrasion properties in harsh environments such as thermal and chemical erosion.

Fiber matrix ceramics composites are lightweight and have good mechanical and thermal properties at high temperatures. Due to these characteristics, fiber-reinforced ceramic composites are applied to friction and abrasion materials such as brake discs and pads for aircraft and land vehicles, ceramic engines requiring mechanical strength, corrosion resistance and heat resistance at high temperatures, and ultra-high heat resistance materials for rocket nozzle parts. It is becoming. Fiber-reinforced ceramic composites have been studied to overcome the drawbacks of brittle fracture of ceramic materials, and heat-resistant materials such as pyrolytic carbon, silicon carbide or boron nitride can be used to break pores of preforms made of carbon or silicon carbide fibers. Prepared by filling with

Until now, fiber-reinforced ceramic composites have been manufactured in various manufacturing processes, but in most cases, fiber damage is caused by mechanical and thermal shocks during the manufacturing process. To solve this problem, the ceramic composite deposits a ceramic matrix by thermal decomposition after injecting a gaseous precursor into a low density porous fiber preform. This process is called chemical vapor infiltration, and this manufacturing process solves the problem of fiber damage caused by conventional ceramic composites by depositing matrix phase at low temperature and pressure conditions.

However, these processes use expensive raw materials and manufacturing equipment, and because their manufacturing processes are complex and require more than several hundred hours of processing time, their applications are very limited to advanced industries such as space and aerospace.

Unlike the chemical vapor permeation process using gaseous raw gas, a process for producing a carbon fiber reinforced ceramic composite by impregnating liquid silicon into a porous carbon preform has been developed.

Walter Krenkel et al., In US Pat. Nos. 6,308,808, 6,358,565 and 5,942,064, prepared carbon fiber reinforced carbon composites by molding a cut carbon fiber, liquid phenol and carbon powder mixture under high temperature and high pressure. Liquid silicon was infiltrated into the carbon fiber reinforced carbon composite thus prepared to apply the carbon fiber reinforced ceramic composite to brake discs of land vehicles and heat-resistant materials for aerospace and aviation.

However, the carbon fiber reinforced resin composite prepared by mixing the liquid carbon precursor as described above is more efficient than the conventional chemical vapor infiltration process in terms of manufacturing cost, but it is difficult to form a uniform carbon fiber protective layer. It is difficult to prevent the carbon fiber reaction, which drastically reduced the mechanical properties of the carbon fiber reinforced ceramic composite. In order to solve such a problem, Korean Patent Application No. 1999-7008146 and US Patent Nos. 6079525, US 6030913 and US 6231791 repeatedly manufacture the carbon fiber reinforced ceramic composite by impregnating the liquid organic binder or changing the composition of the mixture. However, it was not possible to prevent mechanical property deterioration and to improve the high temperature friction and wear characteristics by carbon fiber erosion.

In a process different from that described in US Pat. No. 6,221,475 and Korean Patent Application No. 1999-7003211, pyrolyzed carbon is deposited by isothermal / isobaric chemical vapor infiltration (ICVI). After the carbon precursor was further densified by the liquid phase impregnation method to prepare a carbon fiber reinforced ceramic composite. This process has achieved excellent performance in terms of fiber protection, but it is difficult to combine different carbon fiber reinforced ceramic composites into one structure, which makes it difficult to manufacture a complex carbon fiber reinforced ceramic composite. In particular, the manufacturing process is complicated, and the manufacturing time takes more than several hundred hours, resulting in an increase in manufacturing cost.

Considering the problems related to the manufacturing technology of the carbon fiber reinforced ceramic composites up to now, in most cases, a large amount of manufacturing cost is put into the manufacturing process of the carbon fiber reinforced carbon composites used for the production of the carbon fiber reinforced ceramic composites. It can be seen that there is a problem. For example, the conventional chemical vapor permeation process has excellent properties as a fiber protective layer, but is not suitable for the production of carbon fiber reinforced carbon composites due to the expensive raw materials and difficulties in the manufacturing process. In addition, when the carbon fiber reinforced resin composite is manufactured using the impregnation process of the organic binder containing the carbon component, it can be seen that the repeated impregnation process is required and its efficacy is reduced in terms of fiber protection.

The present invention is to solve the above problems, an object of the present invention is to improve the thermal and mechanical properties of the carbon fiber reinforced ceramic composite by improving the starting material and carbon fiber reinforced carbon composite manufacturing method required for the production of carbon fiber reinforced ceramic composite And to provide a carbon fiber reinforced ceramic composite manufacturing method that solves the above problems due to expensive manufacturing costs and processes.

In order to solve the above problems, the present inventors simplified the manufacturing process using a carbon felt preform, a sandwich structure or a carbon fiber mixture as a starting material, and a carbon fiber reinforced carbon composite having a uniform fiber protective layer in a fast and inexpensive process. In order to provide a rapid thermal gradient chemical vapor permeation process, and together with the liquid silicon infiltration process to provide a method for producing a carbon fiber reinforced ceramic composite.

Carbon fiber reinforced ceramic composite (C _f / C-SiC) manufacturing method according to the present invention for achieving the above object is a step of preparing a carbon fiber reinforced resin composite molded from a mixture of carbon fiber and carbon-containing polymer precursor Wow; Manufacturing a carbon fiber reinforced carbon composite by depositing pyrolytic carbon by a rapid thermal gradient chemical vapor permeation process while increasing the deposition rate from the inside to the outside by high temperature heat treatment of the carbon fiber reinforced resin composite; It characterized in that the step of penetrating the liquid silicon into the pores of the carbon fiber reinforced carbon composite.

And preferably the mixture is characterized in that the carbon fiber is contained 10 to 60w%, the carbon-containing polymer precursor 30 to 60wt%.

In addition, the mixture is preferably characterized in that the silicon carbide powder 30wt% or less, carbon powder 30wt% or less.

In addition, the carbon fiber reinforced resin composite is characterized in that the mixture and the carbon fabric is laminated alternately.

Also preferably in the molded body is formed a first surface layer to prevent the reaction of carbon fibers and silicon by the mixture mixed in the mixing process, the first surface layer is a chemical reaction with the liquid silicon in the step of infiltrating the liquid silicon To form a ceramic base layer consisting of silicon carbide and silicon.

Also preferably, the molded body is heat-treated at a temperature of 900 to 2200 ° C. under an inert gas atmosphere, and then a pyrolytic carbon matrix layer, which is a secondary surface layer, is deposited on the primary surface layer in the deposition by the rapid thermal gradient chemical vapor penetration process. It features.

In addition, the pyrolysis reaction temperature is 700 to 1200 ℃ using a hydrocarbon gas in the step of depositing in the rapid thermal gradient chemical vapor infiltration process, characterized in that the reaction pressure is made in the range of 188 ~ 1130torr.

Also preferably in the step of depositing in the rapid thermal gradient chemical vapor penetration process, the deposition region is divided into at least a plurality from the inside to the outside, and characterized in that the deposition at different rates in each region.

In addition, the deposition region is characterized in that the deposition from the inside to the outside in the deposition rate range of 0.5 ~ 3.0 mm / hr.

Also preferably, the carbon fiber reinforced carbon composite 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.

Also preferably, the step of infiltrating the liquid silicon is to laminate the carbon fiber reinforced carbon composite on the silicon powder, and maintain the inside of the reactor to 100torr or less and then heated to a temperature above 1410 ℃, the melting point of the silicon liquid silicon inside the preform While infiltrating into and inducing a chemical reaction with the plurality of carbon layers.

Carbon fiber reinforced ceramic composite manufacturing method according to the present invention for achieving the above object comprises the steps of preparing a carbon felt preform; Preparing a carbon fiber-reinforced carbon composite by depositing the carbon felt preform in a rapid thermal gradient chemical vapor penetration process while increasing the deposition rate from the inside to the outside; It characterized in that the step of penetrating the liquid silicon into the pores of the carbon fiber reinforced carbon composite.

And preferably the carbon felt preform is characterized in that it is made of any one of carbon-based fibers, such as oxyphen, pen, rayon, pitch system.

In addition, the carbon felt preform is preferably a quasi isotropic lamination of the mat, such as 0 ° / +60 ° / -60 °, characterized in that the carbon fiber of less than 10mm in the Z axis.

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

Also preferably, the carbon fiber is reinforced by X, Y, Z triaxial by impregnating the liquid silicon in the carbon fiber reinforced carbon composite in the step of penetrating the liquid silicon.

In addition, the pyrolysis reaction temperature is 700 to 1200 ℃ using a hydrocarbon gas in the step of depositing in the rapid thermal gradient chemical vapor infiltration process, characterized in that the reaction pressure is made in the range of 188 ~ 1130torr.

Also preferably in the step of depositing by the rapid thermal gradient chemical vapor penetration process, the deposition region is divided into at least a plurality from the inside to the outside, and characterized in that the deposition at different rates in each region.

In addition, the deposition region is characterized in that the deposition from the inside to the outside in the deposition rate range of 0.5 ~ 3.0 mm / hr.

Also preferably, the carbon fiber reinforced carbon composite 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.

Also preferably, the step of infiltrating the liquid silicon is to laminate the carbon fiber reinforced carbon composite on the silicon powder, and to maintain the inside of the reactor to 100torr or less and then heated to a temperature above 1410 ℃, the melting point of silicon to the liquid silicon to the carbon It penetrates 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 production method of each mixture in the following examples may be modified in more various ways by modifying a part of its configuration. However, if the modified embodiments include basically the technical components claimed in the present invention, it should be considered that they all fall within the technical scope of the present invention.

First, in terms of starting materials, carbon felt preforms in which carbon fibers are reinforced in X, Y, Z triaxial directions, or carbon fibers having a length of 0.3 to 150 mm, carbon-containing polymer precursors, and silicon carbide A sandwich structure prepared by alternately stacking a mixture of powder and graphite powder and carbon fabrics may be applied, or a carbon fiber reinforced resin composite (CFRP) consisting of the above mixture may be used.

The prepared starting material is a pyrolytic carbon layer deposited by a rapid thermal gradient chemical vapor permeation process to be described below to prepare a porous carbon fiber reinforced carbon composite, and infiltrate liquid silicon into open pores in the carbon fiber reinforced carbon composite to obtain carbon. Prepare fiber reinforced ceramic composites. The carbon fiber-reinforced ceramic composite has a physical 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.

Method for producing a carbon fiber reinforced ceramic composite according to the present invention can be divided into two processes according to the starting material as shown in Figure 1 and FIG.

First, the process illustrated in FIG. 1 is a process of preparing a carbon fiber reinforced resin composite using a carbon fabric and a mixture of carbon fiber, carbon-containing polymer precursor, silicon carbide powder, and graphite powder cut into a size of 0.3 to 150 mm.

In the carbon fiber reinforced resin composite manufacturing step, a carbon fiber cut to a size of 0.3 ~ 150 mm is put in distilled water together with a carbon-containing polymer precursor, silicon carbide powder and graphite powder to prepare a uniform mixture through a process of dispersion and mixing.

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

The mixture thus prepared is alternately laminated together with the carbon fabric to form a green body of a sandwich structure (S110). Carbon fabrics can be plain, runner or twill. Here, as another method of producing a molded article, it is possible to manufacture by only laminating the mixture without alternating laminating the carbon fabric.

Thereafter, the prepared molded product is charged into a molding mold, and then a carbon fiber reinforced resin composite is prepared by simultaneously applying 80 to 250 ° C. heat and a pressure of 1 to 20 MPa. At this time, the carbon fiber reinforced resin composite prepared had a value of an apparent density of 1.2 to 1.6 g / cm 3 and an apparent porosity of 1 to 20%. (S110) (S120) (S130)

The above method for producing a carbon fiber reinforced resin composite may be applied by applying the technical details described in Korean Patent Application No. 1995-0069130 and Korean Patent Application No. 1997-0023344 filed by the present applicant in another embodiment.

Next, the step (S140) of depositing by a rapid thermal gradient chemical vapor infiltration process heat-treats the prepared carbon fiber reinforced resin composite at a temperature of 700 to 2200 ° C. under an inert gas atmosphere, and then performs a rapid thermal gradient chemical vapor penetration process. A step of preparing a carbon fiber reinforced carbon composite.

Specifically, the rapid thermal gradient chemical vapor penetration process of the present invention is for producing a dense carbon fiber-reinforced carbon composite having a density of 1.3 g / cm 3 or more, and the rapid thermal gradient chemical vapor penetration process includes at least three regions to be deposited. By dividing the above, the deposition rate is controlled in each section so that the deposition is performed more rapidly. At this time, the deposition rate control is performed by moving the thermocouple installed inside the chemical vapor deposition apparatus at a high speed gradually from the inside of the molded body to the outside.

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

In addition, the deposition rate arrow shown in the drawing indicates that the shorter one indicates that the deposition rate is slower, and the longer one indicates that the deposition rate is faster. And the T1 portion is hot and the T2 portion is cold, indicating that a thermal gradient is induced.

The deposition rate at this time is deposited from the inside to the outside in the range of 0.5 ~ 3.0 mm / hr. For example, after dividing the area into the inside, the middle part, and the outside, the inside is deposited at 1.0 mm / hr, the middle part is deposited at 1.5 mm / hr, and the outside is deposited at 2.0 mm / hr for faster deposition. . At this time, the deposition rate is slowed in the inside because the deposition in the molded body is relatively slower than the outside.

By controlling the deposition rate in this way, all of the existing methods, such as isothermal / isopressure chemical vapor permeation, pressure gradient chemical vapor permeation, and conventional isothermal thermal gradient chemical vapor permeation, which require high manufacturing costs due to complex processes and long production times. Compared to chemical vapor infiltration process, manufacturing process and manufacturing cost can be improved.

This rapid thermal gradient chemical vapor permeation process is 5 to 10 times faster and denser than the thermal gradient chemical vapor permeation process of Korean Patent No. 0198154, which is the applicant's patent. It is possible to form a pyrolytic carbon layer on the order of μm.

And the pyrolysis carbon layer formed at this time acts as a reaction layer to form a silicon carbide matrix phase by reacting with the liquid silicon in the liquid silicon impregnation process.

The carbon fiber reinforced resin composite prepared by the rapid thermal gradient chemical vapor penetration 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 a carbon fiber reinforced carbon composite prepared by a rapid thermal gradient chemical vapor permeation process on silicon powder in a particle size range of 1 μm to 10 mm.

Process conditions at this time are heated to the temperature of 1410 degreeC or more which is the melting point of silicon in a vacuum atmosphere. Silicon melted at a high temperature of 1410 ° C. or higher fills most of the pores in only a few minutes by capillary force of pores present in the carbon fiber reinforced carbon composite, and at the same time, it is synthesized into silicon carbide by reacting with the carbon reaction layer on the carbon fiber. . The final carbon fiber reinforced ceramic composite thus prepared is composed of 30 to 60 wt% carbon, 35 to 60 wt% silicon carbide and 5 wt% or less unreacted silicon.

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

First, the carbon felt preform reinforced in the X, Y, Z triaxial directions is manufactured (S200). Specifically, the carbon fiber such as oxyphen, pen, rayon, and pitch system is wound around the mandrel to form a one-way carbon mat. To produce a carbon mat laminated in this manner. The lamination method alternately laminates in anisotropic manner, such as 0 ° / + 60 ° / -60 °.

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

The fiber volume of this felt preform is about 10-55%, the thickness of one layer is about 0.1mm or less, the Z-axis fiber length is 10mm or less, and the fiber ratio is about 10%. In addition, the Z axis may use a needle having a density of 15 penetration / cm 3.

Then, to remove impurities of the carbon felt preform, heat treatment is performed at 1700 ° C. or above in a vacuum atmosphere. For a method of manufacturing the carbon felt preform, reference is made to the examples of the US patent application US 10-180778 and Korean Patent No. 27788 filed by the applicant.

Next, a carbon fiber-reinforced carbon composite is manufactured by using a rapid thermal gradient chemical vapor penetration process (S210), wherein the carbon fiber-reinforced carbon using the rapid thermal gradient chemical vapor penetration process mentioned in the first process described above. To prepare a composite (S220).

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

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

<Example 1>

A mixture of 30 wt% carbon fiber cut to 30 mm, 40 wt% phenol resin, 5 wt% carbon powder, and 5 wt% silicon carbide powder was made and alternately laminated with a 20 wt% carbon fiber in the form of a main fabric. The prepared molded article was placed in a molding mold and cured simultaneously with pressing at a pressure of 2 MPa for 10 minutes to prepare a carbon fiber reinforced resin composite.

The carbon fiber reinforced resin composite was subjected to high temperature heat treatment under an inert gas atmosphere. And carbon fiber reinforced carbon composite was prepared by depositing pyrolysis carbon under rapid thermal gradient chemical vapor permeation process conditions.

The carbon fiber reinforced carbon composite prepared as described above was laminated on silicon powder, and heated to 1550 ° C. under vacuum atmosphere to impregnate liquid silicon to prepare a carbon fiber reinforced carbon ceramic composite. At this time, the physical properties of the prepared carbon fiber reinforced ceramic composite are shown in Table 1.

<Example 2>

A molded article was made by making a mixture of 55 wt% carbon fiber, 35 wt% phenol resin, 5 wt% carbon powder, and 5 wt% silicon carbide powder cut into a size of 30 mm. In Example 2, alternating lamination using a carbon fabric was not performed. The prepared molded article was placed in a molding mold and cured simultaneously with pressing at a pressure of 2 MPa for 10 minutes to prepare a carbon fiber reinforced resin composite.

The carbon fiber reinforced resin composite was subjected to high temperature heat treatment under an inert gas atmosphere. And carbon fiber reinforced carbon composite was prepared by depositing pyrolysis carbon under rapid thermal gradient chemical vapor permeation process conditions.

The carbon fiber reinforced carbon composite prepared as described above was laminated on silicon powder, and heated to 1550 ° C. under vacuum atmosphere to impregnate liquid silicon to prepare a carbon fiber reinforced carbon ceramic composite. Physical properties of the prepared carbon fiber reinforced ceramic composite are shown in Table 1.

Example 3

A 320K oxyphene fiber was wound around the mandrel to produce a unidirectional carbon mat, and the carbon mat produced by the above method was laminated. The lamination method alternately laminated by the method of 0 degrees / + 60 degrees / -60 degrees.

After stacking at least two layers, punching was performed using a needle to reinforce each layer in the Z-axis direction, and the above process was repeated to prepare a preform having a thickness of 30 mm. The oxyphene fiber volume ratio of the preform was made to about 45%, the thickness of one layer was about 0.9mm, the fiber ratio of the z-axis was made to about 10%.

The preform prepared as described above was heat treated under vacuum atmosphere at 1700 ° C. to remove impurities.

Carbon fiber reinforced carbon composites were prepared by depositing pyrolyzed carbon on the prepared carbon felt preform under rapid thermal gradient chemical vapor permeation process conditions.

The carbon fiber reinforced carbon composite prepared as described above was laminated on silicon powder, and heated to 1550 ° C. under vacuum atmosphere to impregnate liquid silicon to prepare a carbon fiber reinforced carbon ceramic composite. Physical properties of the prepared carbon fiber reinforced ceramic composite are shown in Table 1.

<Comparative Example 1>

A carbon fiber reinforced resin composite was prepared by mixing 54 wt% of carbon fiber cut to 130 mm in size with 36 wt% of phenol resin and 10 wt% of carbon powder, putting the mixture into a molding mold and curing it under pressure at a pressure of 3 MPa.

The carbon fiber reinforced resin composite was heat-treated at 900 ° C. 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, and heated to 1600 ° C. under vacuum atmosphere to impregnate liquid silicon to prepare a carbon fiber reinforced carbon ceramic composite. Physical properties of the prepared carbon fiber reinforced ceramic composite are shown in Table 1.

Psalter Apparent density Apparent porosity Flexural strength Thermal conductivity Coefficient of friction (g / cm 3) (%) (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 ceramic composite manufacturing method according to the present invention as described above, the carbon fiber of the carbon fiber reinforced carbon composite prepared by the rapid thermal gradient chemical vapor permeation process has a uniformly deposited pyrolytic carbon layer, such a pyrolytic carbon layer Silver is synthesized into silicon carbide by reacting with silicon in the liquid silicon impregnation process. The pyrolytic carbon layer is used to synthesize silicon carbide as well as a fiber protective layer that prevents the erosion of carbon fibers, which is the most problematic problem in the liquid silicon impregnation process. It has excellent properties as a reaction layer and also improves the mechanical properties of the carbon fiber reinforced ceramic composite by forming a new interface between the carbon fiber and the silicon carbide matrix.

As shown in FIG. 3, the microstructure of the carbon fiber-reinforced ceramic composite prepared according to the method of the present invention is a dark gray portion around the carbon fiber pyrolysis carbon layer 102, the light gray portion is a silicon carbide layer 103 And the brightest part is the residual silicon layer 104. There is little erosion of the carbon fiber by the pyrolytic carbon layer around the carbon fiber, and it can be seen that silicon carbide is synthesized around the pyrolytic carbon layer.

In the present invention, the rapid thermal gradient chemical vapor infiltration process has a deposition rate of 10 times or more compared to the conventional chemical vapor infiltration process and 5 times or more than the conventional thermal gradient chemical infiltration process, considering the manufacturing time of the carbon fiber reinforced carbon composite. Since the pyrolysis carbon layer can be deposited, the manufacturing cost of the carbon fiber reinforced carbon composite material can be significantly reduced.

In addition, the carbon fiber reinforced resin composite can be produced in a single process without the repetitive density process as in the carbon fiber reinforced resin composite manufacturing process using the carbon-containing liquid precursor, and the rapid thermal gradient chemical vapor penetration process and liquid phase Since the combination of the silicon impregnation process can simplify the manufacturing process of the carbon fiber reinforced ceramic composite and significantly reduce the manufacturing cost, it is possible to apply the carbon fiber reinforced ceramic composite in various fields.

In addition, a molded article prepared by mixing carbon fibers having a size of 0.3 to 150 mm with a carbon-containing polymer precursor, a silicon carbide powder, and a carbon powder, and then alternately laminating the carbon fabric or using only a mixture is homogeneous in dispersion and mixing. It has excellent properties in forming the primary surface layer. In addition, since shrinkage hardly occurs during the high temperature heat treatment of 1000 ° C. or higher, there is no change in dimensions, thereby greatly reducing the cost required for dimension and shape processing.

Carbon fiber reinforced ceramic composite according to the present invention as described above has the effect of improving the physical properties of the carbon fiber reinforced ceramic composite manufacturing method, compared to all conventional chemical vapor penetration process 5 to 10 times more than the deposition rate of the pyrolysis carbon layer It can be deposited, which greatly improves the manufacturing process, manufacturing time and manufacturing cost.

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

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

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

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

* Description of the symbols for the main parts of the drawings *

101 ... Carbon Fiber

102 ... Pyrolysis Carbon

103.Silicon Carbide

104 ... residual silicon

Claims (21)

Preparing a carbon fiber reinforced resin composite molded into a mixture of carbon fibers and a carbon-containing polymer precursor; Manufacturing a carbon fiber reinforced carbon composite by depositing pyrolytic carbon by a rapid thermal gradient chemical vapor permeation process while increasing the deposition rate from the inside to the outside by high temperature heat treatment of the carbon fiber reinforced resin composite; Method for producing a carbon fiber reinforced ceramic composite, characterized in that the step of infiltrating the liquid silicon into the pores of the carbon fiber reinforced carbon composite. The method of claim 1, wherein the mixture comprises 10 to 60 w% of the carbon fiber and 30 to 60 wt% of the carbon-containing polymer precursor. The method of claim 2, wherein the mixture contains 30 wt% or less of silicon carbide powder and 30 wt% or less of carbon powder. The method of claim 2 or 3, wherein the carbon fiber reinforced resin composite is a carbon fiber reinforced ceramic composite manufacturing method characterized in that the mixture and the carbon fabric laminated alternately. The liquid crystal of claim 4, wherein a primary surface layer is formed on the molded body to prevent reaction between carbon fibers and silicon by the mixture mixed in a mixing process, and the primary surface layer is infiltrated with the liquid silicon. And chemically reacting with each other to form a ceramic matrix layer made of silicon carbide and silicon. The method of claim 1, wherein the molded body is heat-treated at a temperature of 900 ~ 2200 ℃ under an inert gas atmosphere, the pyrolysis carbon base layer is a secondary surface layer on the primary surface layer in the step of depositing by the rapid thermal gradient chemical vapor penetration process Carbon fiber reinforced ceramic composite manufacturing method characterized in that the deposition. The carbon fiber reinforced ceramic composite according to claim 1, wherein the pyrolysis reaction temperature is 700 to 1200 ° C and a reaction pressure of 188 to 1130 torr using hydrocarbon gas in the rapid thermal gradient chemical vapor infiltration process. Way. The method of claim 1, wherein in the step of depositing by the rapid thermal gradient chemical vapor infiltration process, at least a plurality of deposition areas are divided from inside to outside, and carbon fiber reinforced ceramics are deposited at different rates in each area. Composite manufacturing method. The method of claim 1, wherein the deposition region 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 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 infiltration of the liquid silicon is carried out by laminating the carbon fiber-reinforced carbon composite on the silicon powder, maintaining the inside of the reactor at 100torr or less, and then heating the liquid silicon to a temperature of at least 1410 ° C, which is the melting point of silicon. The method of manufacturing a carbon fiber reinforced ceramic composite, which infiltrates into the preform and induces a chemical reaction with the plurality of carbon layers. Preparing a carbon felt preform; Preparing a carbon fiber-reinforced carbon composite by depositing the carbon felt preform in a rapid thermal gradient chemical vapor penetration process while increasing the deposition rate from the inside to the outside; Method for producing a carbon fiber reinforced ceramic composite, characterized in that the step of infiltrating the liquid silicon into the pores of the carbon fiber reinforced carbon composite. 13. The method of claim 12, wherein the carbon felt preform is made of any one of carbon-based fibers such as oxyphen, pen, rayon, and pitch system. 13. The carbon felt preform according to claim 12, wherein the carbon felt preform has quasi-isotropy such as 0 ° / + 60 ° / -60 °, and carbon fiber reinforcement of 10 mm or less in the Z axis is reinforced. Ceramic composite manufacturing method. 13. The method of claim 12, wherein the carbon felt preform is deposited with a pyrolytic carbon layer having a thickness of 5 to 100 µm by the deposition by the rapid thermal gradient chemical vapor penetration process. The method of claim 12, wherein impregnating the carbon fiber reinforced carbon composite with liquid silicon in the step of infiltrating the liquid silicon, the carbon fiber reinforced ceramic composite is characterized in that the carbon fiber reinforced by X, Y, Z triaxial. . The carbon fiber reinforced ceramic composite according to claim 12, wherein the pyrolysis reaction temperature is 700 to 1200 ° C and a reaction pressure of 188 to 1130 torr using hydrocarbon gas in the rapid thermal gradient chemical vapor infiltration process. Way. 13. The method of claim 12, wherein in the step of depositing by the rapid thermal gradient chemical vapor infiltration process, the deposition region is divided into at least a plurality from inside to outside, and carbon fiber reinforced ceramics are deposited at different speeds in each region. Composite manufacturing method. The method of claim 12, wherein the deposition region 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 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 12, wherein the infiltration of the liquid silicon is carried out by laminating the carbon fiber-reinforced carbon composite on the silicon powder, maintaining the inside of the reactor at 100torr or less, and then heating the liquid silicon to a temperature of at least 1410 ° C, which is the melting point of silicon. Infiltrating the inside of the carbon felt preform and at the same time induce a chemical reaction with a plurality of carbon layer carbon fiber reinforced ceramic composite manufacturing method.