JP2018095508A - PRODUCTION METHOD OF SiC FIBER-REINFORCED SiC COMPOSITE MATERIAL - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method of a SiC fiber-reinforced SiC composite material which prevents fluffing even when SiC fibers are bent with a small radius of curvature.SOLUTION: The production method of the SiC fiber-reinforced SiC composite material includes: a substrate formation step S1 of forming a substrate 4 from a strand 3 composed of a plurality of carbon fibers 2 and a sizing agent 1; a sizing agent removal step S2 of removing the sizing agent 1 from the substrate 4; a SiC coating formation step S3 of placing the substrate 4 in a CVD furnace and forming a SiC coating 5 on its surface by using the carbon fiber 2 as a core; an interface layer formation step S4 of forming an interface layer 7 on the outside of the SiC coating 5; and a matrix formation step S5 of forming a SiC matrix 8 on the outside of the interface layer 7. As the substrate 4 is formed in the stage of the carbon fiber 2 on which strong frictional force less tends to generate, hence fluffing can be suppressed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing a SiC fiber-reinforced SiC composite material.

  Since ceramic composites have heat resistance, oxidation resistance, damage tolerance, etc., they are expected to be used in fields with severe usage environments such as the energy industry, aerospace, and nonferrous metals. Among them, silicon carbide fiber reinforced silicon carbide composite material (hereinafter referred to as SiC fiber reinforced SiC composite material) using silicon carbide fiber (hereinafter referred to as SiC fiber) as the reinforcing fiber and silicon carbide as the matrix is expected to have excellent characteristics. It is growing.

  The SiC fiber reinforced SiC composite material forms an interface layer made of a foreign substance such as BN and pyrolytic carbon between the strands of the SiC fiber, which is an aggregate, and the SiC matrix, thereby integrating the SiC fiber and the SiC matrix. Preventing and exhibiting the characteristics as a composite material. SiC fiber reinforced SiC composite materials include various forms of SiC fiber reinforced SiC composite materials such as cloth woven from strands of bundled SiC fibers and wound filament winding. Can be formed.

  Patent Document 1 discloses a method for manufacturing a polygonal tubular body, in which ceramic fibers are wound around a polygonal mandrel having an R-shaped portion on a longitudinal side, and a plurality of layers having different winding angles with respect to the axis of the mandrel are formed. A winding process for obtaining a wound body in which ceramic fiber layers are laminated; a CVD process for coating the wound body with ceramic-CVD to form a covering; and a mandrel removing process for removing a mandrel from the covering. The ceramic fiber layer is made of a ceramic / ceramic composite material in which the outermost ceramic fiber layer has a smaller winding angle with respect to the axis of the mandrel than the ceramic fiber layer immediately below the outermost ceramic fiber layer. A method for producing a polygonal tubular body is described.

  By disposing the SiC fiber layer having a small winding angle with respect to the axis of the mandrel in the outermost layer as described above, the outermost SiC fiber can be gently bent and hardly broken. That is, it is possible to cover the SiC fiber layer that is easily fluffed with the SiC fiber layer that is difficult to fluff, and to suppress the occurrence of fluff.

JP 2016-13950 A

  However, since the SiC fiber is originally a brittle material, it is cut when a force is applied locally. When a small-diameter pipe or the like is formed using a strand that is a bundle of SiC fibers, the SiC fibers break due to the brittleness of the SiC, and fuzz easily occurs. When fluffing occurs, it causes a decrease in strength. In addition, when a matrix is formed by CVD in the process of forming an SiC fiber reinforced SiC composite material, the matrix grows on the fluffed SiC fiber, which becomes a source of defects. .

  In view of the above problems, an object of the present invention is to provide a method for producing a SiC fiber-reinforced SiC composite material in which fluffing hardly occurs even when SiC fibers are bent with a small radius of curvature.

The manufacturing method of the SiC fiber reinforced SiC composite material of the present invention for solving the above-mentioned problems is as follows.
(1) A base material forming step of forming a base material using a strand composed of a plurality of carbon fibers and a sizing agent, a sizing agent removing step of removing the sizing agent from the base material, and the base material in a CVD furnace In addition, a SiC coating forming step of forming a SiC coating on the surface with the carbon fiber as a core, an interface layer forming step of forming an interface layer outside the SiC coating, and forming a SiC matrix outside the interface layer A matrix forming step.

  The manufacturing method of the SiC fiber reinforced SiC composite material of this invention forms the base material using the strand which consists of carbon fiber and a sizing agent. Since carbon has a hexagonal crystal structure in which the c-axis direction is bonded by van der Waals force, it has a lubricating action, and a strong force is not easily applied to the carbon fiber. Even if the base material is formed in a form such as cloth, the base material is formed at the carbon fiber stage where a strong frictional force is unlikely to be generated on the surface, so that the occurrence of fuzz can be reduced. Furthermore, since the strand has a sizing agent, the friction between the fibers is further reduced, making it difficult to cut.

  In the method for producing a SiC fiber reinforced SiC composite material according to the present invention, the aggregate is formed by weaving and winding at the carbon fiber stage. Therefore, at the stage of forming the aggregate, the ceramic coating serving as an interface layer is formed on the surface. There is no. For this reason, the ceramic coating on the surface is not peeled off and the ceramic fibers are not damaged, and it is possible to make it difficult to generate fuzz.

  The method for producing a SiC fiber-reinforced SiC composite material of the present invention preferably has the following aspect.

  (2) The base material forming step includes at least one of a weaving method of weaving cloth, a braiding method of knitting a braided body, or a filament winding method of winding a filament winding body.

  In the weaving method, the braiding method, and the filament winding method, an aggregate is formed by combining and bending continuous SiC fibers. For this reason, when the fiber is cut and fluffed, a gap is formed in the SiC fiber, and it becomes difficult for the SiC matrix to completely fill the gap, and a defect is easily formed in the SiC matrix. In the manufacturing method of the SiC fiber reinforced SiC composite material according to the present invention, the SiC matrix is easily filled between the aggregates because the SiC fiber is not easily cut even at a bent portion, and a strong SiC fiber reinforced SiC composite material is obtained. Can do.

  (3) The sizing agent removal step is either a cleaning method or a heating method.

  Examples of the sizing agent include epoxy resins, polypropylene, polyethylene, vinyl ester resins, silicone resins, hydrazide resins, and polyethylene oxide. By removing these sizing agents, SiC can be formed directly on the carbon fibers. The method for removing the sizing agent can be appropriately selected according to the type of the sizing agent. If it is a water-soluble sizing agent, it can be washed with water, and if it is soluble in an organic solvent, it can be washed using an organic solvent. In addition, a sizing agent that can be heated to a temperature equal to or higher than its boiling point and sublimation point, or a sizing agent that is thermally decomposed and does not leave a residue, can be removed by heating, evaporation, sublimation, or thermal decomposition.

  Moreover, the manufacturing method of the SiC fiber reinforced SiC composite material of this invention removes a sizing agent after forming a base material using several carbon fiber, forms SiC coating | cover on carbon fiber, and obtains SiC fiber. Yes. Since the SiC fiber obtained by the present invention is obtained by the CVD method, it does not contain oxygen unlike the SiC fiber obtained by spinning the precursor. When oxygen is contained, it reacts with SiC at a high temperature, decomposes into a gas such as SiO and CO, and becomes a source of forming defects in the SiC fiber. Since the SiC fiber of the present invention has CVD-SiC formed on the core of the carbon fiber, it is possible to obtain a SiC fiber-reinforced SiC composite material that does not contain oxygen and has high heat resistance.

  In the method for producing a SiC fiber-reinforced SiC composite material of the present invention, an interface layer is formed on the surface of the obtained SiC fiber. The interfacial layer prevents the integration of the SiC fiber and the SiC matrix after the SiC fiber reinforced SiC composite material is formed and acts so that the SiC fiber is pulled out of the matrix, so that the performance as a composite material is exhibited. Will be able to.

  The method for producing a SiC fiber-reinforced SiC composite material of the present invention further includes a matrix forming step of forming a SiC matrix outside the interface layer. In the matrix formation step, a CVD method in which a source gas is deposited between the SiC fibers of the aggregate, a precursor method in which the aggregate is impregnated with a precursor resin, and then thermally decomposed can be used.

  (4) The interface layer is made of BN or pyrolytic carbon.

  BN or pyrolytic carbon, which is an interface layer, is a hexagonal crystal and has a crystal structure that is easy to cleave because the c-axis direction is bonded by van der Waals force. For this reason, when the interface layer is made of these ceramics, the matrix and the SiC fiber as the aggregate prevent the integration, and the SiC fiber acts so that the SiC fiber is pulled out from the matrix. The performance can be demonstrated.

  (5) The matrix forming step includes a CVD method or a precursor method.

  In the CVD method, the matrix gap can be filled into the gaps of the aggregate by depositing the raw material gas which is a gas, and impregnating the precursor which is a liquid in the precursor method, so that it is possible to efficiently form a SiC fiber reinforced SiC composite material. it can.

  (6) The strand further contains an organic fiber and has an organic fiber removing step of removing the organic fiber between the base material forming step and the SiC coating forming step.

  In the manufacturing method of the SiC fiber reinforced SiC composite material of the present invention, when the strand contains organic fibers, the friction between the carbon fibers can be reduced when the aggregate is formed, and the breakage of the carbon fibers can be prevented. . Moreover, since the organic fiber has been removed by the SiC coating formation step, the SiC coating can be formed in a sufficient thickness in the gap after the organic fiber is removed.

  (7) The organic fiber removing step is performed simultaneously with the sizing agent removing step.

  The removal of the organic fiber and the removal of the sizing agent can be performed by the same process. For this reason, the organic fiber and the sizing agent can be simultaneously removed by the same treatment by appropriately selecting the combination of the organic fiber and the sizing agent.

  The manufacturing method of the SiC fiber reinforced SiC composite material of this invention forms the base material using the strand which consists of carbon fiber and a sizing agent. Since carbon has a hexagonal crystal structure in which the c-axis direction is bonded by van der Waals force, it has a lubricating action, and a strong force is not easily applied to the carbon fiber. For this reason, even if the base material is formed in a form such as a cloth, the base material is formed at the carbon fiber stage where a strong frictional force is unlikely to be generated on the surface, so that the occurrence of fuzz can be reduced. Furthermore, since the strand has a sizing agent, the friction between the fibers is further reduced, making it difficult to cut.

  In the method for producing a SiC fiber reinforced SiC composite material according to the present invention, the aggregate is formed by weaving and winding at the carbon fiber stage. Therefore, at the stage of forming the aggregate, the ceramic coating serving as an interface layer is formed on the surface. There is no. For this reason, the ceramic coating on the surface does not peel off and the ceramic fibers are not damaged. For this reason, it can be made difficult to generate fuzz.

(A) is process flowchart figure of the manufacturing method of the SiC fiber reinforced SiC composite material of Embodiment 1 which concerns on this invention, (b) is the manufacturing method of the SiC fiber reinforced SiC composite material of Embodiment 2 which concerns on this invention. Process flowchart figure, (c) shows the process flowchart figure of the manufacturing method of the SiC fiber reinforced SiC composite material of Embodiment 3 which concerns on this invention. In the manufacturing method of the SiC fiber reinforced SiC composite material of Embodiment 1 which concerns on this invention, it is the schematic diagram which imaged the process in which a SiC fiber reinforced SiC composite material is formed, (a) is a base-material formation process, (b ) Shows the sizing agent removal step, (c) shows the SiC coating formation step, (d) shows the interface layer formation step, and (e) shows the matrix formation step. In the manufacturing method of the SiC fiber reinforced SiC composite material of Embodiment 2 which concerns on this invention, it is the schematic diagram which imaged the process in which a SiC fiber reinforced SiC composite material is formed, (a) is a base-material formation process, (b ) Shows the sizing agent removal step, (c) shows the SiC coating formation step, (d) shows the interface layer formation step, and (e) shows the matrix formation step.

(Detailed description of the invention)
The manufacturing method of the SiC fiber reinforced SiC composite material of the present invention includes a base material forming step of forming a base material using a strand composed of a plurality of carbon fibers and a sizing agent, and a sizing that removes the sizing agent from the base material. An agent removing step, an SiC layer forming step for forming an SiC coating on the surface with the carbon fiber as a core, and an interface layer forming step for forming an interface layer outside the SiC coating; Forming a SiC matrix outside the interface layer.

  The manufacturing method of the SiC fiber reinforced SiC composite material of this invention forms the base material using the strand which consists of carbon fiber and a sizing agent. Since carbon has a hexagonal crystal structure in which the c-axis direction is bonded by van der Waals force, it has a lubricating action, and a strong force is not easily applied to the carbon fiber. Even if the base material is formed in a form such as cloth, the base material is formed at the carbon fiber stage where a strong frictional force is unlikely to be generated on the surface, so that the occurrence of fuzz can be reduced. Furthermore, since the strand has a sizing agent, the friction between the fibers is further reduced, making it difficult to cut.

  In the method for producing a SiC fiber reinforced SiC composite material according to the present invention, the aggregate is formed by weaving and winding at the carbon fiber stage. Therefore, at the stage of forming the aggregate, the ceramic coating serving as an interface layer is formed on the surface. There is no. For this reason, the ceramic coating on the surface is not peeled off and the ceramic fibers are not damaged, and it is possible to make it difficult to generate fuzz.

  The method for producing a SiC fiber-reinforced SiC composite material of the present invention preferably has the following aspect.

  The base material forming step includes at least one of a weaving method of weaving cloth, a braiding method of knitting a braided body, or a filament winding method of winding a filament winding body.

  In the weaving method, the braiding method, and the filament winding method, an aggregate is formed by combining and bending continuous SiC fibers. For this reason, when the fiber is cut and fluffed, a gap is formed in the SiC fiber, and it becomes difficult for the SiC matrix to completely fill the gap, and a defect is easily formed in the SiC matrix. In the manufacturing method of the SiC fiber reinforced SiC composite material according to the present invention, the SiC matrix is easily filled between the aggregates because the SiC fiber is not easily cut even at a bent portion, and a strong SiC fiber reinforced SiC composite material is obtained. Can do.

  The sizing agent removal step is either a cleaning method or a heating method.

  Examples of the sizing agent include epoxy resins, polypropylene, polyethylene, vinyl ester resins, silicone resins, hydrazide resins, and polyethylene oxide. By removing these sizing agents, SiC can be formed directly on the carbon fibers. The method for removing the sizing agent can be appropriately selected according to the type of the sizing agent. If it is a water-soluble sizing agent, it can be washed with water, and if it is soluble in an organic solvent, it can be washed using an organic solvent. In addition, a sizing agent that can be heated to a temperature equal to or higher than its boiling point and sublimation point, or a sizing agent that is thermally decomposed and does not leave a residue, can be removed by heating, evaporation, sublimation, or thermal decomposition.

  Moreover, the manufacturing method of the SiC fiber reinforced SiC composite material of this invention removes a sizing agent after forming a base material, forms SiC coating | cover, and obtains SiC fiber. Since the SiC fiber obtained by the present invention is obtained by the CVD method, it does not contain oxygen unlike the SiC fiber obtained by spinning the precursor. When oxygen is contained, it reacts with SiC at a high temperature, decomposes into a gas such as SiO and CO, and becomes a source of forming defects in the SiC fiber. Since the SiC fiber of the present invention has SiC formed on the core of the carbon fiber, it can contain an SiC fiber-reinforced SiC composite material that does not contain oxygen and has high heat resistance.

  In the method for producing a SiC fiber-reinforced SiC composite material of the present invention, an interface layer is formed on the surface of the obtained SiC fiber. The interface layer prevents the integration of the SiC fiber and the SiC matrix after the SiC fiber reinforced SiC composite material is formed and acts so that the SiC fiber is pulled out of the matrix, so that the performance as a composite material does not break at a stretch. Can be demonstrated.

  The method for producing a SiC fiber-reinforced SiC composite material of the present invention further includes a matrix forming step of forming a SiC matrix outside the interface layer. In the matrix formation step, a CVD method in which a source gas is deposited between the SiC fibers of the aggregate, a precursor method in which the aggregate is impregnated with a precursor resin, and then thermally decomposed can be used.

    The interface layer is made of BN or pyrolytic carbon.

  BN or pyrolytic carbon, which is an interface layer, is a hexagonal crystal and has a crystal structure that is easy to cleave because the c-axis direction is bonded by van der Waals force. Therefore, when the interface layer is made of these ceramics, the matrix and the SiC fiber as the aggregate prevent the integration, and the SiC fiber acts so that the SiC fiber is pulled out from the matrix, so that the performance as a composite material is exhibited. Will be able to. The thickness of the interface layer is not particularly limited. A preferable thickness of the interface layer is, for example, 0.3 to 10 μm. If it is 0.3 μm or more, it can be made difficult to diffuse and disappear even after long-term use. If it is 10 μm or less, the volume of the interface layer occupying the entire volume of the SiC fiber-reinforced SiC composite material can be reduced, so that a high-strength SiC fiber-reinforced SiC composite material can be obtained.

  The matrix forming step includes a CVD method or a precursor method.

  In the CVD method, the matrix gap can be filled into the gaps of the aggregate by depositing the raw material gas which is a gas, and impregnating the precursor which is a liquid in the precursor method, so that it is possible to efficiently form a SiC fiber reinforced SiC composite material. it can.

  The strand further contains an organic fiber and has an organic fiber removing step of removing the organic fiber between the base material forming step and the SiC coating forming step.

  When the strand of the manufacturing method of the SiC fiber reinforced SiC composite material of the present invention contains organic fibers, the friction between the carbon fibers can be reduced when the aggregate is formed, and the breakage of the carbon fibers can be prevented. . Moreover, since the organic fiber has been removed by the SiC coating formation step, the SiC coating can be formed in a sufficient thickness in the gap after the organic fiber is removed.

  The organic fiber removing step is performed simultaneously with the sizing agent removing step.

  The removal of the organic fiber and the removal of the sizing agent can be performed by the same process. For this reason, the organic fiber and the sizing agent can be simultaneously removed by the same treatment by appropriately selecting the combination of the organic fiber and the sizing agent.

(Mode for carrying out the invention)
The manufacturing method of the SiC fiber reinforced SiC composite material of the present invention will be described below with reference to examples.

<Embodiment 1>
Fig.1 (a) is a flowchart figure which shows the process of the manufacturing method of the SiC fiber reinforced SiC composite material of Embodiment 1 which concerns on this invention. See FIG. 2 for a schematic diagram of each process in which the SiC fiber-reinforced SiC composite material is formed.

  The first embodiment includes a base material forming step S1, a sizing agent removing step S2, a SiC coating forming step S3, an interface layer forming step S4, and a matrix forming step S5.

  The base material forming step S1 forms the base material 4 in a form in which cloth is laminated using the strands 3 of the carbon fibers 2 bundled with the sizing agent 1 (see FIG. 2A). In addition, the strand 3 consists of 200-200 carbon fibers 2 and the sizing agent 1, for example, and the organic fiber is not contained. For example, the thickness of the carbon fiber 2 is 3 to 20 μm, and the carbon fiber 2 is combined into one strand 3 by the sizing agent 1. For example, the sizing agent 1 is an epoxy resin and is a thermosetting resin, so it is insoluble in a solvent but can be thermally decomposed in an inert gas.

  The strand 3 composed of the sizing agent 1 and the carbon fiber 2 is woven into a cloth, and a plurality of sheets can be laminated to obtain the base material 4. In addition, the base material 4 is not limited to the form of a cloth, A filament winding body, a braiding body, etc. can be utilized.

  Next, the sizing agent 1 is removed in the sizing agent removing step S2 (see FIG. 2B). Depending on the type of the sizing agent 1, the process of the sizing agent removing step S2 can be appropriately selected.

  If the sizing agent 1 is a solvent-soluble sizing agent 1, it can be removed by a solvent, and if the sizing agent 1 is thermally decomposed in an inert gas, it is thermally decomposed without leaving a residue by heating in an inert gas. Can do. By removing the sizing agent 1 from the base material 4, the voids in the base material 4 can be enlarged.

  As the solvent, carboxylic acid esters such as ethyl acetate, acetone, ethers, toluene, water and the like can be used. The sizing agent 1 is removed by washing in these solvents. Further, when washing with a solvent, in order to increase the permeation power of the solvent, it may be auxiliary such as ultrasonic washing or heating. Moreover, when removing the sizing agent 1 by thermal decomposition, it can be thermally decomposed or volatilized and removed by heating in air, nitrogen gas, noble gas, or vacuum, for example. In the base material 4 from which the sizing agent 1 is removed in this way, many voids are formed around the carbon fiber 2.

  Next, the SiC coating 5 is formed around the carbon fiber 2 in the SiC coating forming step S3. That is, the SiC coating 5 is formed on the surface with the carbon fiber 2 as a core. Here, SiC fiber 6 having a carbon fiber core is formed (see FIG. 2C).

In the SiC coating forming step S3, the periphery of the carbon fiber 2 is covered with CVD-SiC (SiC coating 5). Since CVD-SiC does not contain oxygen in the source gas, it does not generate gases such as SiO and CO even at high temperatures, and the carbon fiber 2 that is the core material is stable at high temperatures, so it has high heat resistance. have.
The thickness of the SiC fiber 6 having the core of the carbon fiber 2 is, for example, 20 to 70 μm.

  In the SiC coating forming step S3, it is preferable to adjust the CVD conditions so that the CVD-SiC layer (SiC coating 5) is not formed concentrated on the surface of the substrate 4. The film-forming temperature of CVD is 1000-1500 degreeC, for example. Moreover, the pressure in a CVD furnace is 1-100 kPa, for example.

  Next, in the interface layer forming step S4, the interface layer 7 is formed on the surface of the obtained SiC fiber 6 (see FIG. 2D).

  The interface layer 7 is formed by a CVD method. The interface layer 7 is made of a ceramic different from SiC in order to prevent integration of the SiC fibers 6 and the SiC matrix 8. Examples of the interface layer 7 include BN and pyrolytic carbon. Since these compounds have a hexagonal crystal structure, they have cleavage planes that are bonded by weakly bonded van der Waals forces, preventing the integration of the SiC fiber 6 and the SiC matrix 8, as a composite material It is possible to sufficiently exhibit the pulling effect. The pulling effect is that the composite material is broken while the fibers are pulled out from the matrix, and the breakage does not proceed at a stretch, and the shape can be maintained.

  In the interface layer forming step S4, since the interface layer is formed by the CVD method, after forming the SiC coating 5 around the carbon fiber 2 in the SiC coating forming step S3, the raw material gas and the conditions are appropriately changed, and the continuous 1 Can be manufactured in one device.

  Next, in matrix formation process S5, the SiC matrix 8 is formed on the SiC fiber 6 with which the interface layer 7 was formed (refer FIG.2 (e)).

  Although the method of forming the SiC matrix 8 is not particularly limited, for example, a CVD method or a precursor method can be used. The CVD method can be performed in the same manner as the SiC coating forming step S3 while changing the conditions as appropriate so that the SiC matrix 8 can be filled in the gaps between the SiC fibers 6. In the precursor method, it can be obtained by impregnating a liquid precursor and then firing. The precursor is not particularly limited as long as SiC can be obtained by firing, and for example, polycarbosilane and derivatives thereof can be used. Of these, the CVD method is preferably used. In the CVD method, since oxygen is not contained in the source gas, gas such as SiO and CO is not generated even at a high temperature and has high heat resistance.

  The film forming temperature in the CVD method is 1000 to 1500 ° C., for example. Moreover, the pressure in a CVD furnace is 1-100 kPa, for example. Moreover, the baking temperature in a precursor method is 600-1200 degreeC.

<Embodiment 2>
FIG.1 (b) is a flowchart figure which shows the process of the manufacturing method of the SiC fiber reinforced SiC composite material of Embodiment 2 which concerns on this invention. In Embodiment 2, refer to FIG. 3 for a schematic diagram of each process in which the SiC fiber-reinforced SiC composite material is formed.

  In the second embodiment, the strand 3 includes the carbon fiber 2, the organic fiber 9, and the sizing agent 1 (see FIG. 3A). The strand 3 is organic simultaneously with the sizing agent removing step S2 in the manufacturing process of the first embodiment. The fiber removal step S6 is different from the first embodiment (see FIG. 3B).

  The organic fiber 9 is not particularly limited, and any organic fiber 9 can be used. However, the organic fiber 9 is preferably a finite-length fiber so that it can be inserted between the continuous fibers of the carbon fiber 2. For example, a bundle of carbon fibers 2 is defibrated by air blow, and organic fibers 9 are inserted therebetween. Thereafter, the sizing agent 1 is applied to obtain a strand 3 composed of the carbon fiber 2, the organic fiber 9, and the sizing agent 1. As the organic fiber 9, any material such as natural fiber and synthetic fiber can be used. Among them, synthetic fibers use a refined raw material, so that there is little mixing of impurities, and a thermoplastic resin is mainly used, so that it is easy to remove with a solvent and it is difficult to leave a residue.

Moreover, organic fiber removal process S6 is also performed simultaneously in sizing agent removal process S2.
The method of the sizing agent removal step S2 performed simultaneously with the organic fiber removal step S6 may be any method and is not particularly limited. In this case, it is necessary that the organic fiber 9 and the sizing agent 1 can be removed by the same method. .
As the removal method, a heating method can be used if thermal decomposition is possible without leaving a residue, and a cleaning method in which cleaning is performed in a solvent can be used if there is a common solvent.

<Embodiment 3>
FIG.1 (c) is a flowchart figure which shows the process of the manufacturing method of the SiC fiber reinforced SiC composite material of Embodiment 3 which concerns on this invention.
The third embodiment is different from the second embodiment in that the sizing agent removal step S2 and the organic fiber removal step S6 are not performed simultaneously, and the organic fiber removal step S6 is performed after the sizing agent removal step S2. It is.
Since the sizing agent removal step S2 and the organic fiber removal step S6 are not performed simultaneously, it is possible to select a removal method suitable for each.

  When natural fibers are used as the organic fibers 9, there are few good solvents that are easy to use. Therefore, it is preferable to use a heating method in which they are baked and thermally decomposed. When a synthetic fiber is used as the organic fiber 9, many fibers are soluble in a solvent, and therefore, a solvent can be appropriately selected and a cleaning method for removing the solvent can be used, and a heating method for thermal decomposition can also be used. Can do.

  It is not limited to the method of a present Example, The order of organic fiber removal process S6 and sizing agent removal process S2 is not specifically limited, Which may be performed first and may be performed simultaneously.

  In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably. In addition, the material, shape, dimension, numerical value, form, number, arrangement location, and the like of each component in the above-described embodiment are arbitrary and are not limited as long as the present invention can be achieved.

  The manufacturing method of the SiC fiber reinforced SiC composite material of the present invention is a field for manufacturing SiC fiber reinforced SiC composite materials used for members of jet engines and gas turbines in addition to channel boxes and fuel cladding tubes of nuclear reactor members. Can be adapted.

DESCRIPTION OF SYMBOLS 1 Sizing agent 2 Carbon fiber 3 Strand 4 Base material 5 SiC coating 6 SiC fiber 7 Interface layer 8 SiC matrix 9 Organic fiber S1 Base material formation process S2 Sizing agent removal process S3 SiC coating formation process S4 Interface layer formation process S5 Matrix formation process S6 Organic fiber removal process

Claims (7)

A base material forming step of forming a base material using a strand composed of a plurality of carbon fibers and a sizing agent;
A sizing agent removing step of removing the sizing agent from the substrate;
A SiC coating forming step of placing the base material in a CVD furnace and forming a SiC coating on the surface with the carbon fiber as a core;
An interface layer forming step of forming an interface layer outside the SiC coating;
A matrix forming step of forming a SiC matrix outside the interface layer;
The manufacturing method of the SiC fiber reinforced SiC composite material containing this.   2. The SiC fiber-reinforced SiC according to claim 1, wherein the base material forming step includes at least one of a weaving method of weaving cloth, a braiding method of knitting a braided body, or a filament winding method of winding a filament winding body. A method for producing a composite material.   The method for producing a SiC fiber-reinforced SiC composite material according to claim 1 or 2, wherein the sizing agent removing step is either a cleaning method or a heating method.   The method for producing a SiC fiber-reinforced SiC composite material according to any one of claims 1 to 3, wherein the interface layer is made of BN or pyrolytic carbon.   The said matrix formation process consists of a CVD method or a precursor method, The manufacturing method of the SiC fiber reinforced SiC composite material of any one of Claim 1 to 4.   The said strand contains an organic fiber further, and has the organic fiber removal process of removing the said organic fiber between the said base material formation process and the said SiC coating | coated formation process. The manufacturing method of the SiC fiber reinforced SiC composite material of description.   The said organic fiber removal process is a manufacturing method of the SiC fiber reinforced SiC composite material of Claim 6 performed simultaneously with the said sizing agent removal process.

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