JPH06340475A - Fiber reinforced ceramic composite material and its production - Google Patents

Abstract

(57) [Summary] (Modified) [Objective] To provide a fiber-reinforced ceramic composite material capable of forming a composite material having a complicated shape and having improved fracture toughness and strength, and a method for producing the same. [Structure] 60 ceramic fibers having a diameter of 3 μm or more and 150 μm or less and a length of 0.1 mm or more and 20 mm or less with respect to the ceramic powder constituting the matrix
A raw material mixture prepared by adding and mixing additives or a dispersion medium at a ratio of less than or equal to volume% is prepared by a casting method,
Molded by any method selected from extrusion molding method, doctor blade method, injection molding method and self-hardening molding method, or cast molding into a preformed body (preform) made of ceramic short fibers molded into a predetermined shape Method, injection molding method, and self-hardening molding method, the matrix is impregnated and injection molded, and degreased and then sintered to manufacture.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber-reinforced ceramic composite material and a method for manufacturing the same, and particularly to a fiber-reinforced ceramic composite material having excellent toughness and reliability and capable of being easily manufactured even in a complicated shape. And a manufacturing method thereof.

[0002]

2. Description of the Related Art Ceramic raw material powders of nitrides, carbides, borides, silicides, etc. of AlN, SiC, Si ₃ N _4, etc. are molded into a predetermined shape, and then the obtained ceramic molded body is formed. Sintered ceramics sintered bodies are generally superior in properties such as hardness, electrical insulation, wear resistance, heat resistance, corrosion resistance, and lightness compared to conventional metal materials, and It is used in a wide range of fields as electronic materials and structural materials such as equipment parts, aircraft parts, automobile parts, electronic devices, precision machine parts, and semiconductor device materials.

However, the ceramics sintered body is inherently weak to tensile stress and has a drawback of so-called brittleness, in which destruction progresses at once. For this reason, in order to enable the application of the ceramic component to the site where high reliability is required, it is strongly required to increase the toughness and increase the fracture energy of the ceramic sintered body.

That is, gas turbine parts, aircraft parts,
Reinforcing fibers made of inorganic substances and metals, whiskers, plates, reinforced materials such as particles are used as ceramic structural parts that require high reliability in addition to heat resistance and high temperature strength, such as ceramic structural parts used for automobile parts. Practical application of ceramic composite materials in which the toughness value, the fracture energy value, etc. have been improved by dispersing and compounding them in a matrix sintered body has been promoted.

Among the above-mentioned ceramic composite materials, those using long fibers as a reinforcing material are excellent in the effect of increasing fracture toughness and fracture energy, and show a great effect in improving reliability, but long fibers are used. Has a problem that it is not easy to form a desired part shape, and anisotropy occurs in material properties by simply arranging one-dimensional single fibers or fiber bundles.

On the other hand, a ceramics composite material using whiskers, plates, particles, etc. as a reinforcing material is excellent in performance of imparting a desired shape, but on the other hand, a significant property improving effect can be obtained as in the case of combining long fibers. There is a problem that there is no. Moreover, the one using short fibers as a reinforcing material has a larger effect of improving the characteristics than whiskers, plates, particles, etc., and is relatively easy to give a shape, and is close to the one using long fibers as a reinforcing material. Improvement of characteristics can be expected.

[0007]

However, the above-mentioned ceramic composite material is an unfinished material as compared with the conventional FRP (fiber reinforced plastic), FRM (fiber reinforced metal) or ceramic monolithic material. In addition, the fibers to be compounded generally hinder shrinkage and densification during sintering,
Since it has the property of deteriorating the strength of the entire composite, it cannot be densified simply by sintering by atmospheric pressure sintering or atmospheric pressure sintering, and it is difficult to manufacture a composite material having high toughness. It was Therefore, in order to form a dense composite material, a method has been adopted in which an external force is applied in a uniaxial direction of a molded body by a hot pressing method to promote densification and to achieve high toughness.

However, since the hot pressing method is a method of sintering while pressing a molded body in a uniaxial direction, the shape of a sample that can be sintered is limited to a small shape having a simple shape such as a flat plate shape. Turbine blades,
There is a problem that it cannot be applied to large products such as vanes and combustors that have different cross-sectional shapes in the pressing direction.

Further, in the conventional fiber-reinforced ceramics composite material, when long fibers are used as a reinforcing material, there is a problem that it is difficult to give a shape and anisotropy is easily generated in material characteristics. When fibers, whiskers, plates, particles, etc. are used as the reinforcing material, there has been a problem in that the characteristic improvement as much as that of long fibers cannot be obtained.

The present invention has been made to solve the above-mentioned problems, and is capable of dealing with the formation of complicated shaped parts, and has a dense fiber-reinforced ceramics composite material with greatly improved fracture toughness and strength. The purpose is to provide.

Another object of the present invention is to make it possible to easily produce various shapes and to further improve the fracture toughness and fracture energy of the fiber-reinforced composite ceramics. It is an object to provide a method for manufacturing a ceramic composite material.

[0012]

In order to achieve the above object, the present inventors have studied various fiber shapes and molding methods for satisfactorily dispersing ceramic fibers by various experiments,
The strength characteristics and the like of the obtained composite materials were compared. as a result,
A ceramic raw material mixture containing ceramic short fibers of a predetermined shape is formed into a predetermined shape by any one of a molding method selected from a casting molding method, an extrusion molding method, a doctor blade method, an injection molding method and a self-hardening molding method. As a result, it has been found that it is possible to obtain a densified fiber-reinforced ceramics composite material that can cope with the formation of complicated shaped parts, has excellent toughness and strength characteristics.

As a result of various studies on fiber composite reinforcement of ceramic materials, ceramic fibers having a specific shape are used, and the packing ratio of the matrix material between the ceramic fibers is increased to densify the matrix. Even when using short ceramic fibers,
It has been found that a significant improvement in characteristics is achieved.

The present invention has been completed based on the above findings.

That is, the fiber-reinforced ceramic composite material according to the present invention comprises 6 ceramic fibers having a diameter of 3 μm or more and 150 μm or less and a length of 0.1 mm or more and 20 mm or less in a matrix composed of a ceramic sintered body.
It is characterized by being dispersed at a ratio of 0% by volume or less.

The material of the ceramic fiber is not particularly limited, and the same ceramic material as the constituent material of the matrix can be used. Specific examples of such ceramic fibers include carbon-silicon fibers (SiC, Si-C-O, Si-Ti-C-O, etc.), S
iC coated fiber (core wire is C, for example), alumina fiber, zirconia fiber, carbon fiber, boron fiber, silicon nitride fiber, Si ₃ N ₄ coated fiber (core wire is C) and mullite (3Al ₂ O ₃ .2SiO _2). ~ 2Al ₂ O ₃ · Si
O ₂ ) It is preferable to use at least one selected from fibers and the like. Further, a coating layer made of C or BN may be formed on the surface of the fiber in order to prevent the reaction between the fiber and the matrix or to improve the slippage at the interface between the two.

Further, in the first method for producing a fiber-reinforced ceramic composite material according to the present invention, the diameter of the ceramic powder constituting the matrix is 3 μm or more and 150 μm or more.
A raw material mixture prepared by adding ceramic fibers having a length of 0.1 mm or more and a length of 0.1 mm or more and 20 mm or less at a ratio of 60% by volume or less and further adding and mixing the additives in a dispersion medium is cast-molded. Method, extrusion molding method, doctor blade method, injection molding method, and self-hardening molding method, the molded body is molded into a predetermined shape, the resulting molded body is degreased, and then sintered. Characterize.

As a second manufacturing method, a raw material slurry whose main component is a starting material of a matrix made of ceramics has a diameter of 3 to 150 μm and a length of 0.1 to 150 μm.
A step of casting into a molding die in which a preform of 20 mm of ceramic fiber is placed to produce a fiber-containing ceramic compact having a desired shape, and the fiber-containing ceramic compact under the conditions according to the constituent material of the matrix. And a step of producing a fiber-containing ceramic composite sintered body by firing. The casting method in the above manufacturing method includes a pressure casting method, a reduced pressure casting method,
Or you may use the casting method which combined both.

Various ceramic materials can be used as the ceramic raw material powder forming the matrix of the above-mentioned ceramic compact and ceramic sintered body. For example, silicon carbide (SiC), aluminum nitride (AlN), nitride Non-oxide general-purpose ceramic materials such as silicon (Si ₃ N ₄ ) and boron nitride (BN), alumina, zirconia, titania, mullite, beryllia,
One or a mixture of two or more oxide-based ceramic raw materials such as cordierite, zircon and sialon is used. Especially for sialon, the composition formula: Si _6-z Al
_z O _z N _8-z (where 0 <z ≦ 4.5) is used. If necessary, a sintering aid or additive such as yttrium oxide, cerium oxide, magnesium carbonate, calcium carbonate or silicic acid is added to the ceramic raw material powder. It is also possible to form the matrix during the reactive sintering process.

Further, the ceramic fibers are dispersed in a matrix composed of a ceramics sintered body, and the ceramics fibers are added to enhance the toughness of the matrix matrix. Specific examples thereof include carbon silicon fibers, alumina fibers, zirconia fibers, and carbon fibers. At least one selected from fibers, boron fibers, silicon nitride fibers and mullite fibers may be used. These ceramic fibers are preferably added in a proportion of 5% by volume or more and 60% by volume or less with respect to the whole composite material. If the added amount exceeds 60% by volume,
It becomes difficult to dispose the matrix matrix uniformly around each fiber, and the strength characteristics of the composite material are rapidly deteriorated due to the occurrence of defects. The preferred amount of addition that produces a combined effect is in the range of 20 to 45% by volume.

The diameter and length of the ceramic fiber have a great influence on the dispersibility and orientation of the fiber in the molded body and the strength characteristics of the composite material. In the present invention, the diameter is 3 to 150 μm and the length is Use short fibers in the range of 0.1 mm to 20 mm. When the diameter is less than 3 μm, the reinforcing effect of the matrix matrix is small, and the diameter is 15
With thick fibers exceeding 0 μm, stress due to the difference in thermal expansion is likely to occur at the boundary interface between the fibers and the matrix matrix, and cracks are likely to occur. In either case, it is difficult to significantly improve the composite effect of the reinforcing fibers. Become.

When the fiber length is less than 0.1 mm, the effect of suppressing the progress of cracks is small and the effect of improving the toughness is also small. On the other hand, when a long fiber having a length of more than 20 mm is used, it is difficult to uniformly disperse the fiber, it is difficult to densify, and the shape-imparting performance is deteriorated. For example, a preform made of ceramic fiber (preform) The ability to form is reduced. In addition, agglomeration of fibers, which is a starting point of breakage, is easily formed, and this agglomeration becomes a defect, resulting in deterioration of strength characteristics.

That is, by using ceramic fibers having a diameter of 3 to 150 μm and a length of 0.1 to 20 mm, it is possible to significantly improve the composite effect of the reinforcing fibers while maintaining good shape imparting performance. Is possible. However, if the content of such ceramic fibers is less than 5% by volume, the shape imparting performance is deteriorated, so the content of ceramic fibers is preferably 5% by volume or more.

The fiber-reinforced ceramics composite material in which the above ceramics fibers are dispersed in a matrix matrix is manufactured, for example, by the following steps. That is, a predetermined amount of ceramic fibers, a sintering aid, and an organic binder are added to a ceramic raw material powder and mixed to prepare a raw material mixture, and the obtained raw material mixture is placed in a dispersion medium such as water or a solvent. Disperse to prepare a slurry, and cast this slurry by a casting method (including reduced pressure, normal pressure and pressure forming method),
A molded product having a predetermined shape is prepared by using an extrusion molding method, a doctor blade method, an injection molding method, and a self-curing molding method.

Here, the self-curing molding method (gel casting method)
Is a method in which an organic binder having a self-curing property is added, and a curing action by polymerization of this organic binder is utilized to form a molded product having a predetermined shape.

In particular, by using the above-mentioned cast molding method, extrusion molding method, self-hardening molding method or injection molding method,
A so-called near net shape molded body having a shape close to the final product shape can be obtained. Further, according to the casting method, it is possible to obtain a molded body in which the ceramic fibers are two-dimensionally oriented on the surface of the molded body along the flow of the dispersion medium absorbed by the water absorbing surface of the molding die. Further, by using the extrusion molding method, the doctor blade method, or the injection molding method, the ceramic fibers are oriented along the extrusion direction or the injection direction of the raw material mixture, so that the formation of the composite material molded body utilizing the orientation of the ceramic fibers is performed. Is also possible.

After drying and degreasing the obtained composite material molded body, in the case of using non-oxide ceramics, in an atmosphere of an inert gas such as N ₂ gas or argon gas, or in the case of oxides, the atmosphere. A fiber-reinforced ceramics composite material as a final product is manufactured by sintering in a temperature range of 1300 to 2100 ° C. for about 1 to 10 hours.

In another method for producing a fiber-reinforced ceramic composite material according to the present invention, first, a raw material slurry having a matrix starting material as a main component is prepared, and the raw material slurry is used as a preform (pre-formed body) made of ceramic fibers. A fiber-containing ceramic compact having a desired shape is produced by performing pressure casting or reduced pressure casting in a forming die in which a reform) is arranged.

Here, the starting material of the matrix in the above-mentioned manufacturing method is the ceramic powder (which may contain a sintering aid, etc.) when the usual sintered ceramics are applied, and the reaction sintered ceramics. When using a starting material, for example, in the case of reaction sintered SiC, Si is used.
If C and carbon, and reaction-sintered Si ₃ N ₄ , silicon or the like is used.

Further, in the molding step of the above-mentioned manufacturing method, the preform made of ceramic fiber can be manufactured by, for example, press molding, cast molding, pressure cast molding, injection molding, extrusion molding, doctor blade molding, self-hardening molding and the like. it can. By applying these molding methods, molding into a desired part shape becomes easy. For example, when producing a thin plate-shaped composite sintered body,
By making a preform by doctor blade molding, a preform having a component shape can be obtained with good reproducibility.

By applying pressure casting to fill the matrix constituent material as in the above manufacturing method, the filling rate of the matrix material between the ceramic fibers can be increased and the density of the ceramic compact is improved. Therefore, it becomes possible to easily densify the matrix in the subsequent firing step. In order to increase the filling rate between the ceramic fibers, it is also effective to modify the fiber surface by performing heat treatment, applying a wetting agent, or the like.

After that, the fiber-containing ceramics composite sintered body (fiber-reinforced ceramics composite material) is obtained by firing the fiber-containing ceramics compact under the conditions depending on the constituent material of the matrix.

[0033]

According to the fiber-reinforced ceramics composite material and the method for producing the same according to the above-mentioned constitution, the raw material mixture prepared by adding and mixing the ceramics short fibers of the predetermined shape to the ceramics powder is cast molding method, extrusion molding method. Method, doctor blade method, injection molding method, or self-curing molding method, it is possible to easily cope with the formation of complicated shaped parts and obtain a dense composite material molded body. Therefore, when the obtained composite material compact is degreased and then sintered, a denser sintered body is obtained, and as a result, a fiber-reinforced ceramic composite material having high strength and excellent toughness is obtained.

Further, by using the above-mentioned casting molding method, injection molding method or self-hardening molding method, a so-called near net shape molded body close to the final product shape can be obtained, and the secondary processing of the composite material is extremely performed. It will be easier.

[0035]

EXAMPLES The present invention will be described more concretely based on the following examples.

Examples 1 to 3 A raw material mixture obtained by adding 5 to 40% by weight of carbon black (C) as a carbon source and a binder to a SiC raw material powder having an average particle size of 4 μm was used as a dispersion medium (solvent). To be dispersed in water and mixed in a pot mixer for 15 hours to prepare a uniform slurry (slip, slurry). Further, as shown in Table 1, chopped SiC with a diameter of 15 μm and a length of 2 mm.
1 fiber each (Si-C-O, trade name: Nicalon)
0% by volume (Example 1), 20% by volume (Example 2), 30
Volume% (Example 3) was added and mixed.

Next, based on the cast molding method (slip casting method), each sludge is cast into a plaster mold with a pressure of 5 kg.
A rectangular columnar SiC compact having a length and width of 50 mm and a height of 30 mm was prepared by injecting / cm ² . Next, this SiC molded body was naturally dried, degreased in a N ₂ gas atmosphere at a temperature of 600 ° C. for 2 hours, and then reactively sintered in a vacuum or an argon gas atmosphere at a temperature of 1400 to 1500 ° C. for 2 to 5 hours. The SiC fiber-reinforced ceramic composite materials according to Examples 1 to 3 were manufactured.

Examples 4 to 6 Si ₃ N ₄ raw powder having an average particle size of 0.4 μm was added with Al ₂ O ₃ and HfO ₂ as sintering aids so that the z value in the Sialon composition formula was 1. To prepare a Sialon raw material powder, and then add a dispersant and an epoxy curing binder to this Sialon raw material powder to disperse it in water as a dispersion medium (solvent), and use a pot mixer. To prepare a uniform slurry (slip, slurry) by mixing for 15 hours at a diameter of 8.5.
μm, 2mm long chopped SiC short fiber (Si-Ti
10% by volume (Example 4), 20% by volume (Example 5), and 30% by volume (Example 6) of -CO, trade name: Tyranno, respectively, were added and mixed.

Next, based on the self-hardening molding method,
Curing initiator was added and mixed for an additional 15 minutes. Then, it is cast in a predetermined mold and the curing is completed in about 2 hours,
A prismatic Sialon compact having a length and width of 50 mm and a height of 30 mm was prepared. Next, after drying this Sialon compact, it was degreased in an N ₂ gas atmosphere at a temperature of 600 ° C. for 2 hours, and then in an argon gas atmosphere at a temperature of 1500 to 1800, respectively.
The SiC fiber-reinforced ceramics composite materials according to Examples 4 to 6 were manufactured by hot press sintering at a temperature of about 100 to 400 kgf / cm ² for ² to 5 hours.

Example 7 Si ₃ N ₄ raw material powder having an average particle size of 0.4 μm was mixed with Al ₂ O ₃ and HfO ₂ as sintering aids so that the z value of the Sialon composition formula was 1. Sialon raw material powder was prepared by mixing, and 20 volume% of chopped carbon (C) short fibers having a diameter of 10 μm and a length of 2 mm were added to the Sialon raw material powder as shown in Table 1, an organic binder and a plasticizer. 5 wt% of dibutyl phthalate (DBP) as an agent was added and uniformly kneaded, and a raw material mixture was injected at a molding temperature of 150 ° C. and a molding pressure of 5 kg / cm ² based on the injection molding method, and the vertical and horizontal dimensions were 5 mm.
A prismatic Sialon compact having a size of 0 mm and a height of 30 mm was prepared. Next, after naturally drying this Sialon molded body, it was degreased in an N ₂ gas atmosphere at a temperature of 600 ° C. for 2 hours, and then in a 6 atm argon gas atmosphere at a temperature of 1700 to 1900 ° C. for 2 to 2.
Sialon fiber reinforced ceramics composite material according to Example 7 was manufactured by pressure sintering for 5 hours.

Example 8 As shown in Table 1, 20% by volume of chopped carbon (C) short fibers having a diameter of 10 μm and a length of 2 mm was added to a SiC raw material powder having an average particle size of 0.4 μm as a sintering aid. 1% by weight with respect to the SiC raw material powder, 2% by weight of carbon black (C) as a sintering aid, and 5% by weight of polyvinyl alcohol as an organic binder and a plasticizer. Based on the extrusion molding method, the raw material mixture added and uniformly kneaded is extruded at a molding temperature of 150 ° C., and the vertical and horizontal dimensions are 50 mm
A prismatic SiC compact having a height of 30 mm was prepared. Next, after the SiC molded body is naturally dried and degreased in a N ₂ gas atmosphere at a temperature of 600 ° C. for 2 hours, the temperature is 1800 to 2000 ° C. and a pressure of 100 to 100 ° C. in an argon gas atmosphere of 6 atm.
Hot-press sintering was performed at 400 kgf / cm ² for ² to 5 hours to manufacture a C fiber-reinforced ceramics composite material according to Example 8.

Comparative Examples 1 to 3 SiC raw material powder having an average particle size of 4 μm was added with 5 to 5 as a carbon source.
40% by weight of carbon black (C), a binder,
As shown in Table 1, 2 pieces of chopped SiC short fibers (Si—C—O, trade name: Nicalon) having a diameter of 15 μm and a length of 2 mm are used.
0% by volume (Comparative Example 1), 20 vol% SiC continuous fiber (Si—C—O, trade name: Nicalon) with a diameter of 15 μm (Comparative Example 2), SiC whiskers with a diameter of 1 μm and a length of 45 μm (trade name: 20% by volume of Toka Whiskers (Comparative Example 3) was added and mixed in a pot mixer for 15 hours to prepare uniform raw material mixtures.

Next, based on the press molding method, the above Comparative Example 1 was used.
After granulating the above raw material mixture, press-molding it at a pressure of 600 kgf / cm ² to form a prismatic column having a vertical and horizontal dimensions of 50 mm and a height of 30 mm.
A SiC compact was prepared. Moreover, the raw material mixture slurries of Comparative Examples 2 and 3 were prepared, and the slurry was subjected to pressure casting in a mold at a pressure of 40 kgf / cm ² , so that the vertical and horizontal dimensions were 50.
A prismatic SiC compact having a size of 30 mm and a height of 30 mm was formed.
Next, after naturally drying each of the SiC molded bodies, degreasing is performed in a N ₂ gas atmosphere at a temperature of 600 ° C. for 2 hours, and then in a vacuum or in an argon gas atmosphere at a temperature of 1400 to 1500 ° C. for 2 to 5
After time-reaction sintering, SiC fiber-reinforced ceramic composite materials according to Comparative Examples 1 to 3 were manufactured.

With respect to each of the fiber-reinforced ceramic composite materials according to Examples 1 to 8 and Comparative Examples 1 to 3 thus prepared, their density, 3-point bending strength and fracture toughness value were measured and shown in the right column of Table 1 below. I got the result.

[0045]

[Table 1]

As is clear from the results shown in Table 1, a raw material mixture obtained by mixing ceramic powder with ceramic short fibers having a predetermined shape was formed by a casting method, an injection molding method or an extrusion molding method. The fiber-reinforced ceramic composite materials of Examples 1 to 8 manufactured by degreasing and sintering the molded body have a higher density and promoted densification as compared with Comparative Examples 1 to 3, and have three-point bending strength and It was confirmed that the fracture toughness value had extremely excellent characteristics.
Further, when the structure structure of each composite material was observed using an optical microscope, ceramic short fibers were oriented in the longitudinal direction or the surface portion in the matrix made of the ceramic sintered body, and the orientation of these fibers was observed. It can be confirmed that the composite can be densified and brings high toughness and strength to the composite material.

On the other hand, as shown in Comparative Examples 1 to 3, the above raw material mixture was press-molded or cast-molded to obtain a molded body.
The fiber-reinforced ceramic composite materials of Comparative Examples 1 to 3 produced by degreasing and sintering this molded body have isotropic density of the ceramic fibers dispersed in the molded body, and the shrinkage due to sintering is hindered. However, the strength and the fracture toughness were relatively low, and the reinforcing effect of the fibers was also small.

In the above examples, SiC is used as the ceramic raw material for forming the matrix, and SiC chops (Si-C-O, S) are used as the ceramic fibers.
i-Ti-CO), an example using carbon fiber chops is shown, but the present invention is not limited to the above raw materials. That is, as a ceramic raw material, Si ₃ N ₄ , Al ₂ O ₃ ,
Even when AlN or the like is used and alumina fiber, zirconia fiber, boron fiber, Si ₃ N ₄ or mullite is used as the ceramic fiber, the same densification effect and toughness effect as the results shown in Table 1 are obtained. It was confirmed by experiments that it could be demonstrated.

As for the molding method, a so-called near net shape molded body having a complex shape close to the final product shape can be obtained by adopting a casting molding method, an injection molding method, an extrusion molding method or a self-hardening molding method. It was possible to mass-produce, and it was possible to efficiently manufacture a densified fiber-reinforced ceramics composite material even if it had a complicated shape.
Further, in addition to the above molding method, the same effect was obtained when the molded body was formed by using the doctor blade method and the self-curing molding method.

Example 9 First, a SiC short fiber (Si-) having a diameter of 15 μm and a length of 5 mm was used.
C-O, trade name: Nicalon) was blended in paraffin wax at 30% by volume and dispersed by heating and kneading. Next, this short fiber-blended wax was applied to a part shape (gas turbine blade, rough dimensions: width 40
mm × height 70 mm × wall thickness 5 mm), and then degreased in nitrogen at 400 ° C. The degreased body was a preform composed of the above-mentioned SiC short fibers and having sound and shape-retaining strength.

On the other hand, as a starting material for the matrix, sialon powder having an average particle size of 1.1 μm was prepared and wet-mixed in water to prepare a raw material slurry (powder concentration: 50% by volume).

Next, a preform made of the above-mentioned SiC short fibers is placed in a resin mold of a pressure casting machine having the same shape as that of the above-mentioned gas turbine component, and the above-mentioned raw material slurry is pressed at a pressure of 40 kg / cm ² from above. Was pressure-filled, and the pressure was maintained for 5 minutes to prepare a short fiber preform-containing sialon molded body.

[0053] After this, the short fiber preform containing sialon molded product was dried and degreased, were embedded in BN powder under a pressure of 400 kg / cm ^2, at 1550 ° C. 2
Hold for time and hot press sinter.

A 3 × 4 × 40 mm test piece was cut out from the thus obtained component-shaped fiber-reinforced sialon composite sintered body, and the three-point bending strength at room temperature to 1200 ° C. was measured. The maximum stress was 520 MPa, It was confirmed that the material displacement up to breakage was about 1000 μm, which was a good value, and the fracture mode did not show catastrophic fracture, and was excellent in reliability.

Example 10 As a reinforcing fiber, diameter 85 μm, length 10 mm and 20
mm short SiC fiber (SiC coated fiber, trade name: SCS-
9) was prepared. This SiC short fiber was mixed with sialon powder having an average particle size of 1.1 μm as a starting material of a matrix so as to be 30% by weight, and this was wet mixed in water to obtain a raw material slurry (powder and short fiber concentration). : 50
Volume%).

40 kg of this raw material slurry was placed in a resin mold of a pressure casting machine having the same part shape as in Example 9.
It was pressure-filled at a pressure of / cm ² and held at that pressure for 5 minutes to prepare a short fiber-containing sialon molded body.

Thereafter, the short fiber-containing sialon compact was dried and degreased, and then embedded in BN powder to obtain 40
It was held at 1550 ° C. for 2 hours under a pressure of 0 kg / cm ² to perform hot press sintering.

The characteristics of the fiber-reinforced sialon composite sintered body in the shape of the component thus obtained were measured in the same manner as in Example 9, and the same result as in Example 9 was obtained.

Example 11 As a reinforcing fiber, a SiC short fiber (SiC coated fiber, trade name: SCS-9) having a diameter of 85 μm and a length of 5 mm was prepared. The matrix was reaction-sintered SiC, and C powder and SiC powder were prepared as starting materials for this reaction-sintered SiC. Then, these are wet-mixed in water so that the Si—C—O short fibers are 30% by weight, the C powder is 20% by weight, and the SiC powder is 50% by weight, and a raw material slurry (powder and short fiber concentration : 50% by volume).

Next, the above raw material slurry was placed in a resin mold of a pressure casting machine having the same part shape as in Example 9.
A short fiber-containing molded body was produced by pressure filling at a pressure of 40 kg / cm ² and holding at that pressure for 5 minutes.

Thereafter, the above-mentioned short fiber-containing molded body was treated with Ar.
Inside, it was subjected to Si impregnation reaction sintering under the conditions of 1430 ° C. × 2 hours.

The characteristics of the fiber-reinforced composite sintered body having the reaction-sintered SiC as the matrix thus obtained were measured in the same manner as in Example 9, and similar good results were obtained.

Example 12 In place of the reaction-sintered Si ₃ N ₄ matrix in Example 9, a fiber-reinforced SiC composite sintered body (using a preform made of SiC short fibers) having a similar part shape was prepared. When the characteristics were measured in the same manner as in Example 9, the maximum stress was 450 MPa, and the material displacement before fracture was up to 800 μm.
m was a good value.

As described above, according to the method for producing the fiber-reinforced ceramics of this embodiment, the ceramic fiber of the specific shape is used and the pressure casting is applied to the filling of the matrix constituent material. Various component shapes can be easily produced, and the fracture toughness and fracture energy of the obtained fiber-reinforced ceramic composite material can be further improved.

[0065]

As described above, according to the fiber-reinforced ceramic composite material and the method for producing the same according to the present invention,
A raw material mixture prepared by adding and mixing ceramics short fibers of a predetermined shape to ceramics powder is cast molding method, extrusion molding method, doctor blade method, injection molding method,
Since it is molded into a predetermined shape by the self-curing molding method,
Alternatively, since a matrix is impregnated and injection-molded by a casting method, an injection molding method, a self-hardening molding method, etc. into a preformed body (preform) made of ceramic short fibers molded into a predetermined shape, a complicated part shape is formed. A composite molding that can be accommodated is obtained. Therefore, even when the obtained composite material compact is degreased and then sintered by various sintering methods, a dense and high-strength fiber-reinforced ceramic composite material is obtained, which is excellent in toughness.

In particular, it is possible to provide a high-density fiber-reinforced ceramic composite material having a complicated shape with less restrictions on the product shape which has been a problem with the conventional long-fiber composite ceramics.

Further, the above-mentioned cast molding method, extrusion molding method,
By using the self-curing molding method or the injection molding method, a so-called near net shape molded body close to the final product shape can be obtained, and the secondary processing of the composite material becomes extremely easy.

Claims (6)

[Claims] 1. A ceramic sintered body having 6 matrixes of ceramic fibers having a diameter of 3 μm or more and 150 μm or less and a length of 0.1 mm or more and 20 mm or less.
A fiber-reinforced ceramics composite material characterized by being dispersed in a proportion of 0% by volume or less. 2. A ceramic powder constituting a matrix, having a diameter of 3 μm or more and 150 μm or less,
A raw material mixture prepared by adding ceramic fibers having a length of 0.1 mm or more and 20 mm or less at a ratio of 60% by volume or less, and further adding and mixing an additive or a dispersion medium is used. Manufacture of a fiber-reinforced ceramics composite material characterized by forming into a predetermined shape by any one of a molding method selected from a doctor blade method, an injection molding method and a self-hardening molding method, and degreasing and sintering the obtained molded body. Method. 3. The fiber reinforced according to claim 2, wherein the molded body is sintered by an atmospheric pressure sintering method, an atmosphere pressure sintering method, a hot pressing method, a reaction sintering method, or a combination thereof. Manufacturing method of ceramic composite material. 4. A raw material slurry containing a starting material of a matrix made of ceramics as a main component and having a diameter of 3 to 15
A fiber-containing ceramic molded body having a desired shape is cast by a pressure casting method and / or a reduced pressure casting method into a molding die in which a preformed body made of ceramic fiber having a length of 0 to 20 mm and a length of 0.1 to 20 mm is arranged. A fiber-reinforced ceramic composite comprising: a step of producing the fiber-containing ceramics compact, and a step of producing the fiber-containing ceramics composite sintered body by firing the fiber-containing ceramics compact under a condition according to a constituent material of the matrix. Material manufacturing method. 5. The method for producing a fiber-reinforced ceramic composite material according to claim 4, wherein the ceramic fiber is
A method for producing a fiber-reinforced ceramic composite material, characterized in that the ceramic composite sintered body contains 5% by volume or more. 6. The method for producing a fiber-reinforced ceramic composite material according to claim 4, wherein the preform made of the ceramic fiber is cast, pressure cast, injection molded, extruded, self-curing or doctor blade molded. A method for producing a fiber-reinforced ceramic composite material, comprising: