JP3588962B2 - Method for producing fiber-reinforced ceramic composite material - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a method for efficiently producing a fiber-reinforced ceramic composite material having a complex shape requiring high heat resistance, high strength, and light weight, and more particularly, to a liner for a jet engine such as an aerospace industry, The present invention relates to a method for efficiently manufacturing a fiber-reinforced ceramic composite material having a complex shape used in various fields such as an exhaust duct by a net shape.
[0002]
Problems to be solved by the prior art and the invention
Hitherto, as inorganic long fiber reinforced ceramic composite materials having high heat resistance, C / C composite materials in which carbon is reinforced by carbon fibers and SiC / SiC composite materials in which silicon carbide is reinforced by silicon carbide fibers have been put to practical use. .
These materials are formed into a complex shape using a woven fabric of inorganic long fibers as a reinforcing material, impregnated with a melt or solution of an inorganic or organic polymer serving as a matrix material, and then fired, if necessary. It is manufactured by a method of repeating the process (impregnation / firing method) or a method of depositing the matrix on the fabric by a gas phase reaction (CVI method, CVD method).
However, in these production methods, it is difficult to produce a completely dense composite material, and about 10% of pores usually remain in the obtained composite material, and the pores serve as defects. There is a problem that it is inferior in point.
[0003]
On the other hand, as a method for producing a single ceramic (mere ceramic not reinforced with fiber), there is a hot press method in which a powder is uniaxially hot-pressed to obtain a dense compact. This method is a method of obtaining ceramics by applying pressure usually at a pressure of 5 to 30 MPa. According to this method, a very dense molded body without pores can be obtained.
However, in this method, although a molded article having a simple shape such as a flat plate can be produced, it is extremely difficult to produce a complicated shape by net shape.
In addition, a method of obtaining a single ceramic by pressurizing (HIP) with a high-pressure gas under heating and hot-pressing a complex-shaped object has also been proposed. Although a compact having a complicated shape can be produced relatively easily, when applied to a fiber-reinforced ceramic composite material, the orientation direction of the fibers is disturbed, and the reinforcing effect of the inorganic fibers is not sufficiently exhibited. There is.
[0004]
In short, in the conventional manufacturing method, it was impossible to manufacture a dense and complex-shaped fiber-reinforced ceramic composite material by a net shape from a preform having many pores obtained by compounding the reinforcing fiber and the matrix powder.
[0005]
Accordingly, an object of the present invention is to provide a method for producing a fiber-reinforced ceramic composite material capable of producing a dense fiber-reinforced ceramic composite material having a complicated shape from a preform having many pores in a net shape. is there.
[0006]
[Means for Solving the Problems]
The present inventors have conducted various studies in order to solve the above problem, and as a result, at least one surface is made of an inorganic reinforcing fiber and a ceramic powder so that the other surface is in contact with the inorganic powder. A fiber-reinforced ceramic composite material can be obtained in a net shape by arranging a preform having many pores in a mold, pressing the inorganic powder at a high temperature and hot-pressing quasi-isotropically. Was found.
[0007]
The present invention has been made based on the above findings, using inorganic reinforcing fibers and ceramic powder, a method for producing a fiber-reinforced ceramic composite material in which a fiber-reinforced ceramic composite material is produced in a net shape,
Arranging a prepreg sheet comprising the inorganic reinforcing fibers and the ceramic powder in a desired shape, a preform forming step of forming a preform of a desired shape,
The preform is placed in a molding die such that at least one surface thereof is in contact with a molding die and the other surface is in contact with a pressure medium made of inorganic powder, and the pressure medium is pressed at a temperature of 1000 ° C. or more. And a hot press forming step of performing hot press forming in a pseudo isotropic manner.I
The inorganic reinforcing fibers are not oriented in the orthogonal three-dimensional direction including the pressing direction of the preform at the time of pressing.It is intended to provide a method for producing a fiber-reinforced ceramics composite material characterized by the above.
[0008]
Further, the present invention provides the above-mentioned production method, wherein the inorganic powder is a powder that does not sinter during hot forming.
Further, the present invention provides the above method, wherein the inorganic powder is a graphite powder or a BN powder.
Further, the present invention provides the above-mentioned production method, wherein the preform has an apparent density of 20% or more of the density of the obtained fiber-reinforced ceramic composite material.
Further, the present invention provides the above production method, wherein the inorganic reinforcing fiber is a carbon fiber, a silicon carbide-based fiber, a silicon nitride-based fiber, or an alumina fiber..
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the method for producing a fiber-reinforced ceramic composite material of the present invention will be described in more detail.
[0010]
As the inorganic reinforcing fibers used in the present invention, carbon fibers, silicon carbide fibers, silicon nitride fibers or alumina fibers are preferably used.
As the carbon fiber, the silicon carbide fiber, the silicon nitride fiber, and the alumina fiber, the following fibers (1) to (5) are preferably used. When used, these can be used as a mixture.
[0011]
(1) an amorphous material substantially consisting of Si, Ti and / or Zr, C, and O;
A crystalline aggregate of the amorphous and β-SiC of 500 ° or less, preferably 10 to 100 °, and TiC and / or ZrC, or
An amorphous mixed system composed of the crystalline material and SiOx present in the vicinity thereof and TiOx and / or ZrOx (0 <x ≦ 2);
The elemental composition is silicon carbide fiber in which Si is 45 to 60 wt%, Ti and / or Zr is 0.2 to 5 wt%, C is 20 to 45 wt%, and O is 0.1 to 20.0 wt%.
[0012]
(2) The elemental composition is such that Si is 30 to 80 wt%, C is 20 to 70 wt%, H is 2 wt% or less, preferably 0.5 wt% or less (H is preferably 0 wt%, although it is ideally preferable. , May be mixed during the manufacturing process), and
A silicon carbide-based fiber consisting essentially of amorphous Si and C and / or β-SiC crystalline and carbon aggregates of 10000 ° or less, preferably 10 to 2000 °.
The silicon carbide-based fiber (2) may be obtained by a CVD method using a normal carbon fiber or a tungsten fiber as a core wire.
[0013]
(3) The elemental composition is 30 to 80 wt% of Si, 10 to 65 wt% of C, 0.05 to 25 wt% of O, 2 wt% or less, preferably 0.5 wt% or less (H is 0 wt% Is ideally preferable, but may be mixed during the manufacturing process), and
An amorphous substance substantially consisting of Si, C and O, or a crystalline aggregate of β-SiC of 1000 ° or less, preferably 0.1 to 200 °, more preferably 10 to 200 °, and amorphous SiO₂And a silicon carbide fiber which is an aggregate consisting of:
[0014]
(4) Si, N and O, C, H, and metals (at least one selected from the group of metal elements of Groups II to VIII of the Periodic Table of the Elements), and the ratio of each element is atomic Expressed as a ratio
N / Si = 0.3-3
0 / Si = 15, preferably 0.01 to 1
C / Si = 7 or less, preferably 0.01 to 1
H / Si = 1 or less, preferably 0.01 to 0.2
Metals / Si = 5 or less, preferably 0.01 to 0.1
And
Nitriding with X-ray small angle disturbance intensity ratio of 1 to 20 times at 1 ° and 0.5 ° respectively
Silicon fiber.
[0015]
(5) Mullite consisting essentially of A1, Si, B and 0 and / or gamma-alumina and -alumina microcrystals and amorphous Si0₂Alumina fibers that are aggregates with
[0016]
Here, the silicon carbide of the above (1)Elementary“Near the vicinity” in the system fiber is preferably a region whose distance from the crystalline particles is 100 nm or less.
The “carbon aggregate” in the above (2) means that a plurality of crystalline and / or amorphous carbon particles having a size of 1000 ° or less exist.
Further, the “crystalline aggregate” in the above (3) means an aggregate of a plurality of crystals having a size of 0.1 to 1000 μm, and refers to “a crystalline aggregate and an amorphous aggregate”. The aggregate comprising crystalline Si02 "means that a plurality of amorphous SiO2 particles are present in the vicinity of the aggregate of crystals having a size of 0.1 to 1000 .mu.m (synonymous with" the vicinity "above). What is obtained by assembling means what is further obtained by assembling a plurality. Note that the number of crystals to be assembled is not limited.
Specific examples of the metals used in the above (4) include aluminum, titanium, and zirconium.
[0017]
The X-ray small-angle scattering intensity ratio was measured as follows.
A PSPC (Position Detection Proportional Counter) -5 is connected to "RJ-200B" manufactured by Rigaku Denki Co., Ltd., the tube voltage is 45 KV, the tube current is 95 mA, and the first and second slits are 0.2 mmφ and 0.15 mmφ, respectively. The scattering intensity was measured by accumulating 1000 seconds every 0.02 °.
In addition, as a sample, a fiber of 15 mm in length cut out from 18 mg was used, and the fiber was uniformly attached to a slit of 10 mm in length and 4 mm in width, and measured. The intensity ratio was calculated by comparing with the air scattering intensity at 1 ° and 0.5 °.
[0018]
As the inorganic reinforcing fiber, an inorganic reinforcing fiber made of Si—Ti and / or Zr—CO commercially available as “Tyranno Fiber” (registered trademark) from Ube Industries, Ltd. [the silicon carbide fiber (1) Specific examples of the above)) or inorganic reinforcing fibers made of Si—C—O commercially available as “Nicalon” (registered trademark) or “Hinicalon” (registered trademark) from Nippon Carbon Co., Ltd. Specific examples of 3)], or commercially available products such as SCS series inorganic reinforcing fibers [specific examples of the silicon carbide-based fiber (2)] of Textron, USA, or US Pat. No. 366,943, an inorganic reinforcing fiber substantially consisting of Si, C, O and B [specific examples of the silicon carbide fiber (2)] can also be used.
Also, Al₂O₃Fiber (manufactured by DuPont, 3M, manufactured by Sumitomo Chemical Co., Ltd., etc.) [Specific examples of the above alumina fiber (5)], Si-CN fiber [“HPZ fiber” trade name, Dow Corning [Specific examples of the silicon nitride-based fiber (4)], Si₃N₄Fibers (manufactured by Tonen Corp.) [specific examples of the silicon nitride-based fiber (4)] and the like can also be used.
[0019]
The fiber diameter of the inorganic reinforcing fibers is preferably 1 to 1000 μm.
Further, the fiber length of the inorganic reinforcing fiber is preferably longer than 100 μm.
[0020]
Examples of the ceramic powder used in the present invention include the following.
For example, silicon carbide, silicon nitride, alumina, mullite and the like are used, and as these ceramic powders, powders generally used for producing a sintered body of ceramics are used. A compound containing a sintering aid to be promoted is more preferably used. Further, as the ceramic powder, a ceramic powder which progresses sintering and densification via a liquid phase or a viscous region, such as glass ceramic, is also preferably used. In this case, it is preferable that a heat-resistant crystal phase is precipitated to improve heat resistance, and an aluminosilicate glass-based glass ceramic containing an alkaline earth element is more preferably used. Such glass ceramics include, for example, anorthite (CaO.Al)₂O₃・ 2SiO₂), Kinseki (2MgO.2Al)₂O₃・ 5SiO₂), Barium osmilite (BaO.2MgO.3Al)₂O₃・ 9SiO₂), Celsian (Ba (or Sr) · Al₂O₃・ 2SiO₂) Are preferably used.
[0021]
Further, as the molding die used in the present invention, a molding die generally used for manufacturing ceramics is used, and a die for performing uniaxial hot pressing is also formed of a graphite material. The material is not particularly limited as long as it is made of a material that does not react with the material constituting the preform at the temperature at the time and can sufficiently support the pressure during molding.
[0022]
The inorganic powder used in the present invention is preferably a powder that does not sinter during hot compaction, that is, a powder that does not sinter by pressure heat treatment during compaction. Graphite powder and BN powder, which are self-lubricating powders that can be easily operated such as filling the powder into the inside, are preferably used.
[0023]
Thus, the method for producing a fiber-reinforced ceramic composite material of the present invention is a method for producing a fiber-reinforced ceramic composite material in a net shape using the above-mentioned inorganic reinforcing fiber and the above-mentioned ceramic powder, A prepreg sheet composed of fibers and the ceramic powder is arranged in a desired shape, and a preform forming step of forming a preform of a desired shape, and the preform, at least one surface of which is in contact with a molding die, The other surface is placed in a molding die so as to be in contact with a pressure medium made of inorganic powder, and the pressure medium is pressed at a temperature of 1000 ° C. or higher to perform pseudo-isotropic hot pressing. It can be carried out by performing a pressing step.
Hereinafter, the above manufacturing method will be described in more detail.
[0024]
In the above-mentioned preform forming step, the prepreg sheet can be produced in the same manner as in a conventional method, but specifically, it can be produced as follows. For example, PREWO et al. MATER. SCI. 17 (1982) P1201 to 1206, the fiber can be easily manufactured by passing the spread fiber through a slurry composed of a ceramic powder, an organic binder, and a dispersant, winding and drying. The organic binder and dispersant used at this time can be used without any particular limitation as long as they are usually used for a fiber-reinforced ceramic composite material.
[0025]
There is no particular limitation on the form of use of the inorganic reinforcing fibers as a reinforcing material, and they can be used as continuous fibers. In the prepreg sheet, plain weave, satin weave, multiaxial weave, tertiary weave, and the like It can be used as a sheet-like material in which original fibers or continuous fibers are aligned in one direction.
[0026]
Further, the preform can be obtained by molding the obtained prepreg sheet into a desired shape using a mold having a desired shape.
[0027]
The porosity of the preform is not particularly limited, but the apparent density is preferably 20% or more, more preferably 50 to 80%, based on the density of the obtained fiber-reinforced ceramic composite material. If the apparent density is less than 20% with respect to the density of the obtained fiber-reinforced ceramic composite material, a composite material satisfying desired performance may not be obtained, which is not preferable.
In order to adjust the apparent density of the preform within the above range, for example, it can be performed as follows.
That is, the open pores of the preform are caused by (1) a gap between the ceramic powders generated when the matrix is filled with the ceramic powder, and (2) a gap between the reinforcing fiber and the matrix powder. Therefore, by increasing the concentration of the slurry impregnated in the reinforcing fibers, the above (1) can be reduced and the apparent density of the preform can be adjusted within the above range. Also, by increasing the opening width of the reinforcing fibers during the impregnation of the matrix slurry, the impregnation around the fibers of the slurry is facilitated, the above (2) is reduced, and the apparent density of the preform is adjusted within the above range. can do.
[0028]
In addition, in the obtained preform, the use form of the inorganic reinforcing fibers can be used as a form in which the sheet-like material is laminated, but the fiber orientation is such that the fibers are less likely to bend or shrink due to shrinkage during pressure molding. That is, it is not oriented in the orthogonal three-dimensional direction including the portion where the inorganic reinforcing fibers are oriented in the pressing direction of the preform.To do. For exampleMost fibers are oriented in an oblique three-dimensional direction in which the fibers are oriented at an angle to the pressing direction, or are oriented in a two-dimensional direction in which no fibers are oriented in the pressing direction.You.
That is, the inorganic reinforcing fibers are not oriented in the orthogonal three-dimensional direction including the pressing direction of the preform at the time of pressing.No.
[0029]
In the hot press molding step, the preform is placed in the molding die such that at least one surface thereof is in contact with the molding die and the other surface is in contact with the pressure medium made of the inorganic powder. Here, the "other surface" means a surface other than the surface in contact with the mold.
Next, the above-mentioned pressure medium is hot-press-formed in a pseudo-isotropic manner for 0.5 to 5 hours by pressing the pressure medium at a temperature of 1000 ° C. or higher, preferably 1000 to 1800 ° C., and a pressure of 5 to 150 MPa.
[0030]
The hot press molding step will be described in more detail. The preform, the pressure medium, and the mold are substantially sealed uniaxially in a state where the preform is wrapped by the pressure medium and the mold. It is placed in a die that can be hot pressed or a capsule that can be HIPed.
Then, the die or capsule is heated at the above-mentioned temperature, and is uniaxially pressed or subjected to HIP treatment by applying gas pressure to the capsule, so that the pressure medium is always in a direction perpendicular to the surface of the mold with respect to the preform. The hot pressing process is performed by applying pressure so that pressure is applied to the substrate.
As a result, a desired shape can be obtained in a net shape.
[0031]
As the capsule used at the time of the HIP treatment, a capsule made of a titanium foil or a glass capsule is generally used, but does not react with the material constituting the preform and the inorganic powder as the pressure medium at the temperature at the time of the HIP treatment. The material is not particularly limited as long as it is made of a material capable of deforming gas pressure sufficiently to transmit the gas pressure to the inorganic powder in the capsule during the HIP process.
[0032]
Next, the method for producing the fiber-reinforced ceramic composite material of the present invention will be described in more detail with reference to the drawings.
Here, FIG. 1A is a perspective view showing one embodiment of a molding die used in the manufacturing method of the present invention, and FIG. 1B is a BB cross-sectional view thereof. FIG. 2 is a schematic view showing an outline of a production method of the present invention performed using the molding die and the molding die shown in FIG.
[0033]
In order to carry out the production method of the present invention, first, as shown in FIG. 1, a plurality of prepreg sheets 1 each having inorganic reinforcing fibers 11 oriented at 45 ° are formed in a mold 2 having a desired shape. Are arranged so that their orientation directions are orthogonal to each other to form a desired complicated shape as shown in FIGS. 1 (A) and 1 (B).
The inner surface of the molding die 2 has a substantially cylindrical shape divided into an upper part, a central part, and a lower part. The diameter of the lower part is smaller than the diameter of the upper part, and the central part is constricted. It has been done. Then, this inner surface shape becomes the shape of the preform.
Then, as shown in FIG. 2, the obtained preform 6 has its outer peripheral surface in contact with the inner surface of the mold 2 and its inner peripheral surface in contact with the pressure medium 5 made of graphite powder as an inorganic powder. It is arranged in a composite material molding die 4 and is pressed by the punch rod 3 while heating.
The preform is pressurized by the pressurization from the punch bar 3 via the pressure medium 5, and a cylindrical composite material having a constricted central portion is obtained in a net shape.
[0034]
Next, another embodiment of the manufacturing method of the present invention will be described with reference to FIGS.
Here, FIG. 3 is a perspective view showing one embodiment of a molding die used in the production method of the present invention, and FIG. 4 is a production method of the present invention performed using the molding die and the molding die shown in FIG. It is the schematic which shows the outline of.
[0035]
In order to carry out the production method of the present invention, first, as shown in FIG. 3, an eight-satin weave prepreg in which inorganic reinforcing fibers 11 are oriented in a lattice on the upper surface of a mold 2 having a truncated cone shape. As shown in FIG. 3, a plurality of sheets 1 are arranged so that the seams of the prepreg sheets 1 do not overlap, and a sleeve-shaped preform 6 having a desired complicated shape is obtained.
Then, as shown in FIG. 4, the obtained preform 6 has a composite material whose inner peripheral surface is in contact with the molding die 2 and whose outer peripheral surface is in contact with the pressure medium 5 made of graphite powder as an inorganic powder. It is arranged in a molding die 4 and is pressed by the punch rod 3 while heating. A preform protection plate 7 is provided on the upper surface of the mold 2 to protect the upper edge of the preform 6.
The preform is pressurized by the pressurization from the punch bar 3 via the pressure medium 5, and a sleeve-shaped composite material is obtained in a net shape.
[0036]
Next, another embodiment of the manufacturing method of the present invention will be described with reference to FIGS.
Here, FIG. 5 is a perspective view showing one embodiment of a mold used in the manufacturing method of the present invention, and FIG. 6 performs hot press molding by HIP processing using the mold shown in FIG. It is a schematic diagram showing the outline of the manufacturing method of the present invention.
[0037]
In order to carry out the production method of the present invention, first, as shown in FIG. 5, a prepreg sheet 1 in which inorganic reinforcing fibers 11 are oriented at 0 ° / 90 ° on a mold 2 having a desired shape. A plurality of sheets are arranged so that their respective orientation directions are orthogonal to each other to form a preform having a corrugated shape as shown in FIG.
The molding die 2 is a plate-like body having a corrugated plate on one side as shown in FIG.
As shown in FIG. 6, the obtained preform 6 has a lower surface in a wavy shape and four sides thereof in contact with a die 4 having an edge for protecting the preform edge, and an upper surface formed of inorganic powder. Is placed in a glass capsule 8 for molding a composite material so as to be in contact with a pressure medium 5 made of BN powder as a material, and pressurized by applying a gas pressure by a known method.
Due to this pressurization, the preform is pressurized via the pressure medium 5, and a corrugated composite material is obtained in a net shape.
[0038]
According to the production method of the present invention, a dense fiber-reinforced ceramic composite material having a complicated shape such as a sleeve shape, a corrugated plate shape, or a cylindrical shape having a narrowed central portion can be obtained. The other configuration of such a structure is the same as that of an ordinary composite material depending on the material to be used.
Here, “dense” means that there are substantially no vacancies or the like in the matrix, and specifically, that the apparent density is 95% or more of the theoretical density.
[0039]
【Example】
Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto.
[0040]
[Example 1]
The Si-Ti-CO fiber (trade name "Tyranno fiber F grade", manufactured by Ube Industries, Ltd.) is opened and glass ceramic powder (SrO-MgO-Al) is opened.₂O₃-SiO₂) Was impregnated with a slurry dispersed in a dispersion medium composed of water and an organic binder (polyethylene oxide, hereinafter referred to as “PEO”), wound up, and dried to produce a one-way prepreg sheet.
The obtained prepreg sheets are alternately adhered to the inner surface of a split mold having a curved cylindrical shape shown in FIG. 1 on the inner surface thereof so as to have an orientation of ± 45 ° with respect to the height direction. Got a reform.
The obtained preform was set on a die 4 shown in FIG. 2, and graphite powder was filled as a pressure medium 5 as shown in FIG. The die 4 was set in a hot press and subjected to a pressure heat treatment at a temperature of 1000 ° C. and a pressure of 10 MPa for 20 minutes. A reinforced ceramic composite was obtained.
The obtained fiber-reinforced ceramic composite material was excellent in the following points. Since the obtained fiber-reinforced ceramic composite material is a net shape and does not need to be reworked, in the composite material formed into a desired shape, the reinforcing fibers are oriented along the constricted curved surface without cutting. . Therefore, it is mechanically high in strength, and in particular, the strength at the constricted portion is higher than that of a composite material manufactured by conventional rework.
[0041]
[Example 2]
The Si-Ti-CO fiber (trade name "Tyranno fiber F grade", manufactured by Ube Industries, Ltd.) is opened and glass ceramic powder (MgO-Al₂O₃-SiO₂) Was impregnated with a slurry dispersed in a dispersion medium composed of water and an organic binder (PEO), and wound on a cylindrical drum while drying to produce a prepreg wire. This wire was woven to produce an eight-satin weave fabric (prepreg sheet).
As shown in Fig. 3 of the obtained prepreg sheet, seven layers were wound around the surface of a graphite mold having a truncated cone shape to form a preform. At this time, the direction of the warp of the woven fabric is set to have an angle of 45 ° with respect to the height direction of the truncated cone, and the cuts of each layer are shifted by 45 ° so that they do not overlap each other. Wrapped around.
The forming die around which the obtained preform was wound was set on a die 4 shown in FIG. At this time, a preform protection plate 7 made of a graphite disk was placed on the truncated cone in order to prevent unnecessary pressurization of the edge of the preform. The die 4 was filled with graphite powder as a pressure medium 5.
Next, the die 4 was set in a hot press, and subjected to a pressure heat treatment at a temperature of 1400 ° C. and a pressure of 10 MPa for 5 minutes, and then cooled to 1200 ° C. at a rate of 20 ° C./min. A pressurized heat treatment was performed for a time to obtain a sleeve-shaped fiber-reinforced ceramic composite material.
The obtained fiber-reinforced ceramic composite material was excellent in the following points. The obtained fiber-reinforced ceramic composite material has a net shape and is dense, so that it has a smooth surface without rework. For this reason, it is excellent as a member in a portion accompanied by a high-speed gas flow.
[0042]
[Example 3]
Open the Si-Ti-CO fiber (trade name Tyranno fiber LoxE grade, manufactured by Ube Industries, Ltd.)₃N₄Powder and Al₂O₃And Y₂O₃The sintering aid powder was impregnated with a slurry dispersed in a dispersion medium composed of water and an organic binder (PVA), wound up, and dried to produce a one-way prepreg sheet (alignment direction 0 ° / 90 °). .
The obtained prepreg sheet was laminated on a corrugated plate shown in FIG. 5 such that 25 layers were superposed so that the fiber orientation directions were orthogonal to each other to obtain a preform.
As shown in FIG. 6, the obtained preform 6 is placed on a corrugated plate (die 4) for pressure molding, placed in a glass container, and further placed on the preform 6 as a pressure medium. The BN powder was packed, vacuum evacuation was performed for 10 hours while heating at 500 ° C., and the binder contained in the preform 6 was removed, followed by vacuum sealing and glass encapsulation as shown in FIG. This glass capsule 8 is heated to 1500 ° C. in a known HIP apparatus, then pressurized in argon to a pressure of 30 MPa, heated to 1750 ° C. under the same pressure, and further heat-treated at this temperature and pressure for 1 hour. Thus, a corrugated fiber-reinforced ceramic composite material was obtained.
The obtained fiber-reinforced ceramic composite material was excellent in the following points. The obtained fiber-reinforced ceramic composite material has a net shape and does not require rework. In addition, since the fibers are continuously oriented along the waveform, there is no anisotropy in strength in the liquid portion, and cracks and chipping hardly occur when stress is applied.
[0043]
【The invention's effect】
According to the method for producing a fiber-reinforced ceramic composite material of the present invention, a dense fiber-reinforced ceramic composite material having a complicated shape and a dense shape can be produced from a preform having many pores in a net shape.
More specifically, according to the production method of the present invention, a fiber-reinforced ceramic composite material having a dense and complicated shape can be easily obtained by a net shape. As a result, a composite material having a complicated shape, which had to go through the processing step, can be obtained without going through the processing step, which is advantageous in terms of cost and has a small cutting portion of the reinforcing fiber due to the processing. Thus, a member having higher strength than a conventional member can be obtained.
[Brief explanation of the figure]
FIG. 1A is a perspective view showing one embodiment of a molding die used in the manufacturing method of the present invention, and FIG. 1B is a sectional view taken along line BB.
FIG. 2 is a schematic view showing an outline of a production method of the present invention performed using the molding die and the molding die shown in FIG.
FIG. 3 is a perspective view showing one embodiment of a molding die used in the manufacturing method of the present invention.
FIG. 4 is a schematic view showing an outline of a production method of the present invention performed using the molding die and the molding die shown in FIG. 3;
FIG. 5 is a perspective view showing one embodiment of a molding die used in the production method of the present invention.
FIG. 6 is a schematic view showing an outline of a production method of the present invention in which hot press molding is performed by HIP using the mold shown in FIG.
FIG. 7 is a photograph showing a cylindrical composite material having a complicated shape obtained in an example (a photograph submitted in place of a drawing and showing the structure of a ceramic material).
[Explanation of symbols]
1 Pre-preg sheet
2 Mold
3 punch stick
4 dice
5 Pressure medium
6 preforms
7 Preform protection plate
8 glass capsule

Claims (6)

A method of manufacturing a fiber-reinforced ceramic composite material, wherein the fiber-reinforced ceramic composite material is manufactured in a net shape using inorganic reinforcing fibers and ceramic powder,
Arranging a prepreg sheet comprising the inorganic reinforcing fibers and the ceramic powder in a desired shape, a preform forming step of forming a preform of a desired shape,
The preform is placed in a molding die such that at least one surface thereof is in contact with a molding die and the other surface is in contact with a pressure medium made of inorganic powder, and the pressure medium is pressed at a temperature of 1000 ° C. or more. and hot pressing step of forming hot pressing in a pseudo-isotropic manner, we have rows,
The method for producing a fiber-reinforced ceramic composite material, wherein the inorganic reinforcing fibers are not oriented in a three-dimensional direction orthogonal to the pressing direction of the preform at the time of pressing . The method according to claim 1, wherein the inorganic powder is a powder that does not sinter during hot compaction. 3. The method according to claim 2, wherein the inorganic powder is graphite powder or BN powder. 2. The method according to claim 1, wherein the preform has an apparent density of 20% or more of the density of the obtained fiber-reinforced ceramic composite material. The method according to claim 4, wherein the inorganic reinforcing fibers are carbon fibers, silicon carbide fibers, silicon nitride fibers, or alumina fibers. The method according to any one of claims 1 to 5, wherein the inorganic reinforcing fiber is a continuous fiber.

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