JP6875195B2 - Ceramic composite manufacturing method and combination - Google Patents

Description

The present invention relates to a method for producing a ceramic composite material and a combination thereof.

Ceramic composite materials such as carbon fiber / carbon composite material and SiC fiber / SiC composite material have high heat resistance and high strength, and are therefore expected to be used in various fields. Carbon fiber / carbon composite materials have particularly high heat resistance and high purity, and are therefore used in semiconductor manufacturing equipment, high temperature furnaces, and the like. On the other hand, since the SiC fiber / SiC composite material has oxidation resistance, it is expected to be used for high temperature parts of gas turbines, members of nuclear reactors, and the like.

Patent Document 1 states that workability during cross lamination and shape retention in the carbon / carbon composite molding process are improved to reduce costs and prevent the occurrence of structural defects such as delamination. In order to prevent this, a plurality of carbon fiber cloths are wound around a mandrel with a water-soluble adhesive interposed between them, laminated and adhered to each other, and then dried to form a dry preform, which is pitched on the dry preform. Each of these treatments is repeated multiple times as a firing treatment in the order of impregnation, carbonization treatment, and graphitization treatment, and prior to the firing treatment, a sewing treatment is performed to sew the carbon fiber cloths to the dry preform demolded from the mandrel. A method for producing a carbon / carbon composite material is described in which the dry preform after the sewing treatment is set in another mold and then fired. Further, in the embodiment, the rocket nozzle having a conical shape is described, and the dry preform which is the source of the carbon / carbon composite material is set in a graphite firing mold composed of an upper mold and a lower mold, and pitch impregnated with carbon. It is described that the conversion treatment and the graphitization treatment are repeated.

Japanese Unexamined Patent Publication No. 2000-219577

In Patent Document 1, a rocket nozzle having a conical shape is described as an example. In the case of the conical shape, even if the dry preform contracts, it can move to the tip side of the cone to relax the tension while maintaining the overall shape. However, in the case of complicated three-dimensional shapes such as cylindrical and square pipe shapes, the force is received from the mold as it shrinks, which hinders shrinkage and causes cracks in the ceramic composite material or causes deformation. It becomes.

In view of the above problems, it is an object of the present invention to provide a method for producing a ceramic composite material to be fired without causing deformation or cracking, and a combination including a molded body suitable for firing.

A method for producing a ceramic composite material for solving the above problems is as follows.
(1) A burying step of burying a molded product made of an aggregate made of ceramic fibers and a ceramic precursor in a resin foam, and firing of the molded product together with the foam to make the ceramic precursor ceramic. The step includes a step of removing the foam and a step of removing the foam.

In the method for producing a ceramic composite material of the present invention, a molded product is embedded in a resin foam and then fired together with the foam to make a ceramic precursor ceramic. Therefore, the resin foam softly holds the molded product and the molded product. However, even if the ceramic composite material is fired and shrunk, the ceramic composite material can be prevented from being deformed without receiving a large force from the foam.

(2) The foam is a thermosetting resin.

Since the thermosetting resin is carbonized while maintaining the original foamed state without being softened in the firing process, it can be fired while maintaining the state of holding the molded product.

(3) In the burying step, a liquid resin is foamed and the molded product is embedded in the foam through a film.

Since the liquid resin is foamed, a foam that is in close contact with the molded product can be obtained. Further, since the molded body and the foam are in contact with each other via the film, the molded body and the foam do not adhere to each other and can be easily separated after firing.

(4) The ceramic precursor is characterized by containing ceramic particles.

Since the ceramic precursor contains ceramic particles, the content of the ceramic precursor can be reduced, shrinkage of the molded product during firing can be suppressed, and the force received from the foam can be further reduced.

(5) The ceramic particles are characterized by being carbon and / or SiC.

When the ceramic particles are carbon and / or SiC, they have high heat resistance, so that a ceramic composite material having a high heat resistant temperature can be obtained.

(6) The ceramic fiber is a SiC fiber.

When the ceramic fiber is a SiC fiber, it has high heat resistance and high strength, so that a ceramic composite material having a high heat resistant temperature and high strength can be obtained.

(7) The ceramic precursor is at least one resin selected from pitch, phenol resin, silane resin, furan resin, copna resin, epoxy resin, urethane resin, urea resin, polycarbonate resin, and polyacrylonitrile.

When the ceramic precursor is at least one of the above resins, the obtained ceramic matrix is carbon or SiC, so that a ceramic composite material having a high heat resistant temperature can be obtained.

The combination for solving the above problems is
(8) It is composed of a molded body made of an aggregate made of ceramic fibers and a ceramic precursor, and a resin foam in which the molded body is embedded.

When the combination is composed of a molded body made of an aggregate made of ceramic fibers and a ceramic precursor and a resin foam in which the molded body is embedded, the resin foam is formed into the molded body when the combination is fired. Since the molded product is softly held and ceramicized together, it is possible to prevent the ceramic composite material from being deformed without receiving a large force from the foam even if the molded product is fired and shrunk.

(9) The foam is a thermosetting resin.

When the foam is a thermosetting resin, when the combination is fired, it does not soften, is carbonized while maintaining the original foamed state, and is fired while maintaining the molded body. be able to.

(10) The combination has a film between the molded product and the foam.

When a liquid resin is foamed to obtain a foam that is in close contact with the molded body, the molded body and the foam are in contact with each other via a film, so that the molded body and the foam do not adhere to each other and are easily separated after firing. can do.

(11) The ceramic precursor contains ceramic particles.

When the ceramic precursor contains ceramic particles, the shrinkage of the molded product during firing can be suppressed, and the force received from the foam can be further reduced.

(12) The ceramic particles are carbon and / or SiC.

When the ceramic particles are carbon and / or SiC, they have high heat resistance, so that a ceramic composite material having a high heat resistant temperature can be obtained.

(13) The ceramic fiber is a SiC fiber.

When the ceramic fiber is a SiC fiber, it has high heat resistance and high strength, so that a ceramic composite material having a high heat resistant temperature and high strength can be obtained.

(14) The ceramic precursor is at least one resin selected from pitch, phenol resin, silane resin, furan resin, copna resin, epoxy resin, urethane resin, urea resin, polycarbonate resin, and polyacrylonitrile.

When the ceramic precursor is at least one of the above resins, the obtained ceramic matrix is carbon or SiC, so that a ceramic composite material having a high heat resistant temperature can be obtained.

According to the method for producing a ceramic composite material of the present invention, the molded product is embedded in a foam of resin and then fired together with the foam to make a ceramic precursor ceramic, so that the foam of resin holds the molded product softly. Even if the molded product is fired and shrunk, the ceramic composite material can be prevented from being deformed without receiving a large force from the foam. Further, according to the combination of the present invention, since it is composed of a molded body made of an aggregate made of ceramic fibers and a ceramic precursor and a foam of a resin in which the molded body is embedded, when the combination is fired. , The foam of the resin is ceramicized together while holding the molded body softly, and even if the molded body is fired and shrunk, deformation of the ceramic composite material can be prevented without receiving a large force from the foam.

The front perspective view which shows the appearance of the molded article which concerns on this invention. The flow chart which shows the process flow of this invention. It is a conceptual diagram of the process flow of Example 1 to obtain the ceramic composite material of this invention, (a) the figure which shows the molded body, (b) the conceptual diagram corresponding to the embedding process S1 of FIG. 2, (c) FIG. A conceptual diagram corresponding to the firing step S2, and (d) a conceptual diagram corresponding to the mold release step S3 of FIG. It is a conceptual diagram which shows the detail of the embedding process of Example 1, (a) the figure which shows the process of covering an uncured foam with a resin film, (b) the molded article is placed on the resin film, and the foam is cured. The figure which shows the process, (c) the figure which shows the process of covering a molded body with a resin film, (d) the figure which shows the process of covering a molded body with a foam, and fixing in a foam. A conceptual diagram of the burying process of Example 2 for obtaining the ceramic composite material of the present invention, (a) a developed view of a molded body and a foam (upper mold and lower mold), and (b) a combination diagram of the molded body and the foam. The conceptual diagram of the embedding process of Example 3 to obtain the ceramic composite material of this invention, (a) the molded article and the uncured foam, and (b) the molded article submerged in the foam.

(Detailed description of the invention)
The method for producing a ceramic composite material of the present invention includes a burying step of burying a molded product made of an aggregate made of ceramic fibers and a ceramic precursor in a resin foam, and firing the molded product together with the foam. It includes a firing step of ceramicizing the ceramic precursor and a molding step of removing the foam.

In the method for producing a ceramic composite material of the present invention, a molded product is embedded in a resin foam and then fired together with the foam to make a ceramic precursor ceramic. Therefore, the resin foam softly holds the molded product and the molded product. However, even if the ceramic composite material is fired and shrunk, the ceramic composite material can be prevented from being deformed without receiving a large force from the foam.

The foam is a thermosetting resin.

Since the thermosetting resin is carbonized while maintaining the original foamed state without being softened in the firing process, it can be fired while maintaining the state of holding the molded product.

In the burying step, a liquid resin is foamed and the molded product is embedded in the foam through a film.

Since the liquid resin is foamed, a foam that is in close contact with the molded product can be obtained. Further, since the molded body and the foam are in contact with each other via the film, the molded body and the foam do not adhere to each other and can be easily separated after firing.

The ceramic precursor is characterized by containing ceramic particles.

Since the ceramic precursor contains ceramic particles, shrinkage of the molded product during firing can be suppressed, and the force received from the foam can be further reduced.

The ceramic particles are characterized by being carbon and / or SiC.

When the ceramic particles are carbon and / or SiC, they have high heat resistance, so that a ceramic composite material having a high heat resistant temperature can be obtained. Here, the ceramic particles may be either a mixture of carbon and SiC, or one of them.

The ceramic fiber is characterized by being a SiC fiber.

When the ceramic fiber is a SiC fiber, it has high heat resistance and high strength, so that a ceramic composite material having a high heat resistant temperature and high strength can be obtained.

The ceramic precursor is at least one resin selected from pitch, phenol resin, silane resin, furan resin, copna resin, epoxy resin, urethane resin, urea resin, polycarbonate resin, and polyacrylonitrile.

When the ceramic precursor is at least one of the above resins, the obtained ceramic matrix is carbon or SiC, so that a ceramic composite material having a high heat resistant temperature can be obtained.

The combination of the present invention comprises a molded product made of an aggregate made of ceramic fibers and a ceramic precursor, and a resin foam in which the molded product is embedded.

When the combination is composed of a molded body made of an aggregate made of ceramic fibers and a ceramic precursor and a resin foam in which the molded body is embedded, the resin foam is formed into the molded body when the combination is fired. Since the molded product is softly held and ceramicized together, it is possible to prevent the ceramic composite material from being deformed without receiving a large force from the foam even if the molded product is fired and shrunk.

The foam is a thermosetting resin.

When the foam is a thermosetting resin, when the combination is fired, it does not soften, is carbonized while maintaining the original foamed state, and is fired while maintaining the molded body. be able to.

The combination has a film between the molded product and the foam.

When a liquid resin is foamed to obtain a foam that is in close contact with the molded body, the molded body and the foam are in contact with each other via a film, so that the molded body and the foam do not adhere to each other and are easily separated after firing. can do.

The ceramic precursor contains ceramic particles.

When the ceramic precursor contains ceramic particles, the shrinkage of the molded product during firing can be suppressed, and the force received from the foam can be further reduced.

The ceramic particles are carbon and / or SiC.

When the ceramic particles are carbon and / or SiC, they have high heat resistance, so that a ceramic composite material having a high heat resistant temperature can be obtained. Here, the ceramic particles may be either a mixture of carbon and SiC, or one of them.

The ceramic fiber is a SiC fiber.

When the ceramic fiber is a SiC fiber, it has high heat resistance and high strength, so that a ceramic composite material having a high heat resistant temperature and high strength can be obtained.

The ceramic precursor is at least one resin selected from pitch, phenol resin, silane resin, furan resin, copna resin, epoxy resin, urethane resin, urea resin, polycarbonate resin, and polyacrylonitrile.

When the ceramic precursor is at least one of the above resins, the obtained ceramic matrix is carbon or SiC, so that a ceramic composite material having a high heat resistant temperature can be obtained.

The foam of the resin used in the burying step is not particularly limited, but polyurethane, phenol resin, styrene, polypropylene, melamine, EVA (ethylene vinyl acetate copolymer), polyacrylonitrile, EPDM (ethylene propylene diene rubber) and the like can be used. .. Since these resins can easily obtain foams, they can be used as foams used in the production of the ceramic composite material of the present invention.

Above all, it is preferable to use a foam of a thermosetting resin. The thermoplastic resin is a linear polymer, and the thermosetting resin has a network-like molecular structure. A thermosetting resin is a resin that is synthesized in a network shape using a trifunctional or higher functional monomer and does not melt even when heat is applied. In the present invention, a crosslinked thermoplastic resin can also be used. Since the resin obtained by cross-linking the linear polymer does not melt even when heat is applied, it can also be used as a foam used in the production of the ceramic composite material of the present invention. When the foam of the thermoplastic resin is crosslinked and used, a method of irradiating the foam with an electron beam, radiation or the like to crosslink, a method of adding a crosslinking agent, or the like can be used.

Further, in the burying step, any method may be used for burying. For example, a molded body may be sandwiched and embedded using a set of foams that have been molded and cured using a mold in advance.
Alternatively, the molded product may be embedded in the foam by submerging the molded product in the foam of a liquid resin expanded with gas and curing it as it is. In this case, in order to prevent the molded product from adhering to the resin of the foam, it is preferable to wrap the molded product with a film and then submerge it in the foam of the liquid resin.

A film may be placed on the surface of the liquid resin foam expanded with gas, and the molded product may be pressed from above to cure the liquid resin foam so as to have the shape of the molded product. After the liquid resin foam is cured, the molded product can be completely embedded by further covering the molded product with a film and then covering the molded product with the resin foam.

The film used in the burying process is not particularly limited, but may be impermeable or insoluble in the liquid resin that is the raw material of the foam so that the molded product and the foam do not adhere to each other in the burying process. preferable.

Further, it is desirable that the film used in the firing step does not leave any harmful residue. Harmful residues include those that adhere to the surface after melting, and residues that are thermally decomposed by a resin containing chlorine and contain dioxin. Examples of the film that is impermeable to and insoluble in a liquid resin without leaving such a residue include polyethylene, polypropylene, and cellophane. Cellophane is a film made of cellulose and can be preferably used because it is difficult to dissolve in a solvent and does not soften even when heat is applied. Olefin-based resins such as polyethylene and polypropylene are resins that decompose in the main chain when heat is applied, so that almost no residue remains and chlorine is not contained in the structure, so that they can be preferably used.

(Form for carrying out the invention)
Based on each example, a burying step S1 in which a molded body 1 made of an aggregate made of ceramic fibers and a ceramic precursor is embedded in a resin foam 2, and a molding 1 is fired together with the foam 2 to form a ceramic precursor. The firing step S2 for ceramicizing the body and the mold removal step S3 for removing the foam 2 to obtain the ceramic composite material 5 will be described. The appearance of the molded body 1 is shown in FIG. The flow chart of each step is shown in FIG.

(Example 1)
The first embodiment will be described with reference to FIGS. 3 and 4. 3A and 3B are conceptual diagrams of a process flow corresponding to the flow diagram of FIG. 2, where FIG. 3A shows a molded body 1 and FIG. 3B shows a conceptual diagram corresponding to the burying process S1 of FIG. ) Shows a conceptual diagram corresponding to the firing step S2 of FIG. 2, and FIG. 2D shows a conceptual diagram corresponding to the mold release step S3 of FIG. FIG. 4 is a conceptual diagram showing the details of the burial process.

First, a plain weave cloth woven using strands made of carbon fibers is three-dimensionally laminated so as to have a cone shape to obtain an aggregate. Next, the cone-shaped aggregate is impregnated with a phenol resin containing ceramic particles made of carbon as a ceramic precursor to obtain the molded product 1 shown in FIGS. 1 and 3 (a).

<Buried process: S1>
Next, the box is filled with urethane foam, which is an uncured foam 2, and is covered with a first resin film 3 made of polyethylene (see FIG. 4A). The obtained molded product 1 is placed on the first resin film 3 and slightly submerged so that the urethane foam spreads in the cavity inside the cone. Leave it as it is until the urethane foam is cured (see FIG. 4 (b)). After the urethane foam is cured, the second resin film 4 is further covered (see FIG. 4C), and the uncured urethane foam (foam 2) is sprayed so that no gap is formed. Further, it waits until the urethane foam is cured, and the molded body 1 is fixed in the urethane foam which is the foam 2 (see FIG. 4D).

<Baking process: S2>
Next, the ceramic precursor is carbonized by firing together with the foam 2 to form a carbon matrix.

<Release process: S3>
The ceramic composite material (carbon fiber / carbon composite material) 5 can be obtained by separating from the carbonized foam 2.

(Example 2)
The second embodiment will be described with reference to FIG.

A strand of SiC fiber is wound to obtain a cone-shaped aggregate. The obtained aggregate is impregnated with polycarbosilane to obtain a molded product 1. The surface of the SiC fiber is coated with pyrolytic carbon in advance. The coating of pyrolytic carbon has an important function in preventing the integration of the SiC of the matrix with the SiC fiber and exhibiting the properties as a composite material. The foam 2 is composed of a combination of an upper mold 2a and a lower mold 2b having the same cavity as the cone shape of the aggregate (see FIG. 5A). Since the foam 2 is made of phenol foam and is carbonized while maintaining its shape when fired, the molded product can be retained even after firing.

<Buried process: S1>
The obtained molded product 1 is set in the cavity, the upper mold 2a and the lower mold 2b are combined, and the molded product 1 is embedded in the foam 2 (see FIG. 5 (b)).

<Baking process: S2>
Next, the molded body 1 is fired together with the foam 2 to ceramicize the ceramic precursor to form a SiC matrix.

<Release process: S3>
The ceramic composite (SiC fiber / SiC composite) 5 can be obtained by separating from the carbonized foam.

(Example 3)
The third embodiment will be described with reference to FIG.

<Buried process: S1>
The surface of the cylindrical molded product obtained in the same manner as in Example 1 was covered with a polyethylene film and then submerged in the foam of urethane foam, which is an uncured foam 2, (see FIG. 6A). , Leave until the urethane foam is cured (see FIG. 6 (b)).

Next, after firing in the firing step S2 in the same manner as in Example 1, the foam 2 can be separated in the mold release step S3 to obtain the ceramic composite material 5.

The present invention is not limited to the above-described embodiment, and can be appropriately modified, improved, and the like. In addition, the material, shape, size, numerical value, form, number, arrangement location, etc. of each component in the above-described embodiment are arbitrary and are not limited as long as the present invention can be achieved.

The ceramic composite manufacturing method and combination of the present invention use a ceramic composite that does not cause deformation or cracking, and are required to have high heat resistance, such as a heating furnace member, a semiconductor manufacturing apparatus, and a jet engine component. It can be adapted to such fields.

1 Molded body 2 Foam 3 1st resin film 4 2nd resin film 5 Ceramic composite material

Claims (12)

An embedding process in which a molded body composed of an aggregate made of ceramic fibers and a ceramic precursor is embedded in a foam of a thermosetting resin, and
A firing step of firing the molded product together with the foam to ceramicize the ceramic precursor.
A mold release step for removing the foam and
A method for producing a ceramic composite including. The method for producing a ceramic composite material according to claim 1, wherein the burying step is a method of foaming a liquid resin and burying the molded product in the foam through a film. The method for producing a ceramic composite material according to claim 1 or 2 , wherein the ceramic precursor contains ceramic particles. The method for producing a ceramic composite material according to claim 3 , wherein the ceramic particles are carbon and / or SiC. The method for producing a ceramic composite material according to any one of claims 1 to 4 , wherein the ceramic fiber is a SiC fiber. The ceramic precursor is a pitch, phenolic resins, silane resins, furan resins, COPNA resin, epoxy resin, urethane resin, urea resin, polycarbonate resin, claim 1 is at least one resin selected from polyacrylonitrile 5 The method for producing a ceramic composite material according to any one of the above. A combination of a molded product made of an aggregate made of ceramic fibers and a ceramic precursor, and a foam of a thermosetting resin in which the molded product is embedded. The combination according to claim 7 , wherein the combination has a film between the molded body and the foam. The combination according to claim 7 or 8 , wherein the ceramic precursor contains ceramic particles. The combination according to claim 9 , wherein the ceramic particles are carbon and / or SiC. The combination according to any one of claims 7 to 10 , wherein the ceramic fiber is a SiC fiber. The ceramic precursor is a pitch, phenolic resins, silane resins, furan resins, COPNA resin, epoxy resin, urethane resin, urea resin, polycarbonate resin, claim 7 is at least one resin selected from polyacrylonitrile 11 The combination according to any one of the above items.

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