JP7181718B2 - CERAMIC COMPOSITE AND MANUFACTURING METHOD THEREOF - Google Patents

Description

TECHNICAL FIELD The present invention relates to a ceramic composite and a method for producing the same.

Ceramic bodies made of ceramics are widely used as various structural bodies such as machine elements. The ceramic bodies are of course used singly, but sometimes they are used in combination. In particular, a ceramic composite body has been used in which a plurality of ceramic bodies can be displaced independently of each other but cannot be separated.

For example, Patent Document 1 discloses a bell-shaped capsule structure in which a core made of a sintered ceramic body is positioned in a cavity (capsule) of a shell made of a sintered ceramic body, and these can move independently. A method of manufacture is disclosed. For this structure, two types of ceramic materials with different sintering shrinkage ratios are prepared, the core is formed from a ceramic material with a large sintering shrinkage ratio, and the shell is formed from a ceramic material with a small sintering shrinkage ratio around the core. It is manufactured by firing the formed body.

Further, Patent Document 2 discloses a ceramic bearing in which a large number of ceramic spheres are rotatably embedded in a ceramic base material, and a method of manufacturing the same. This ceramic bearing is manufactured by mixing ceramic spheres coated with a resin on the surface with a ceramic material that serves as a base material, molding the mixture, and then firing the mixture to burn off the resin and form a gap.

Patent No. 4826141 Japanese Patent Publication No. 7-58097

However, in the technique disclosed in Patent Document 1, the configuration is limited to one in which the outer peripheral surface of the core and the inner peripheral surface of the hole of the shell are similar in shape. Further, in the technique disclosed in Patent Document 2, the gap between the ceramic base material and the ceramic sphere is limited to a structure in which the shape of the resin coated on the surface of the ceramic sphere is similar. Thus, in the prior art, only ceramic composites with limited structures were obtained.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a ceramic composite and a method for producing the same, which can be formed in various configurations.

The method for producing a ceramic composite of the present invention comprises the steps of: obtaining a first ceramic member comprising a ceramic sintered body or a ceramic calcined body by heat-treating a ceramic compact at a second temperature; A second ceramic member comprising a ceramic molded body that has not been heat-treated after molding, and has an internal space that communicates with the outside through a first opening and a second opening that is smaller than the first opening , preparing a second ceramic member having a shrinkage rate larger than that of the first ceramic member at a temperature of 1; and heat-treating the first and second ceramic members at the first temperature in the inserted state, whereby the heat-treated first ceramic member is the first ceramic member. The first ceramic sintered body and the heat-treated second ceramic sintered body, which is the second ceramic member , are displaceable and inseparable from each other, and function as a check valve. a heat treatment step for obtaining a composite, wherein the first temperature is equal to or lower than the second temperature, the main components of the first and second ceramic sintered bodies are the same, and the first The purity of the main component of the ceramic sintered body is higher than the purity of the main component of the second ceramic sintered body.
Further, the method for producing a ceramic composite of the present invention comprises the steps of: obtaining a first ceramic member made of a ceramic sintered body or a ceramic calcined body by heat-treating a ceramic compact at a second temperature; A second ceramics member comprising a ceramics molded body that has not been heat-treated after molding a raw material, and having an internal space communicating with the outside through an opening, the second ceramics member being larger than the first ceramics member at a first temperature. a step of preparing a second ceramic member having a shrinkage rate; an inserting step of inserting only a portion of the first ceramic member into the internal space through the opening; By heat-treating the first and second ceramic members at the first temperature, a first ceramic sintered body, which is the heat-treated first ceramic member, and the heat-treated second ceramic member. and a second ceramic sintered body, which is a ceramic member of the second ceramic member, becomes displaceable and inseparable from each other to obtain a ceramic composite that functions as a universal joint, wherein the first temperature is the first 2 or lower, the main components of the first and second ceramic sintered bodies are the same, and the purity of the main components of the first ceramic sintered body is the same as that of the second ceramic sintered body. It is characterized by having a purity higher than that of the main component.

According to the method for producing a ceramic composite of the present invention, it is possible to obtain a ceramic composite having a structure that cannot be obtained by the techniques disclosed in Patent Documents 1 and 2 above.

In the method for producing a ceramic composite of the present invention, the step of heat-treating a ceramic molded body at a second temperature to obtain the first ceramic member made of a ceramic sintered body or a ceramic calcined body, The second ceramic member consists of a ceramic molded body that is not heat-treated after molding the ceramic raw material.

As a result , the first ceramic member made of the ceramic sintered body or the ceramic calcined body does not shrink as much as the second ceramic member made of the ceramic molded body depending on the heating treatment in the heat treatment step. It becomes possible to increase the difference in shrinkage rate, and to diversify the composition of the ceramic composite.

Further, in the method for producing a ceramic composite of the present invention, the second ceramics is formed by molding the ceramics raw material by any one of cold isostatic pressing, injection molding, and slip casting. It is preferable to include a step of producing the ceramic molded body that constitutes the member.

In this case, the ceramic molded body produced by the cold isostatic pressing method, the injection molding method, or the casting method has a suppressed variation in the density of the ceramic molded body compared to the ceramic molded body molded by the uniaxial pressing method. can be As a result, it is possible to suppress a decrease in dimensional accuracy due to variations in the density of the second ceramic member, and consequently, the second ceramic member having a larger shrinkage rate in the heat treatment process than the first ceramic member. It is possible to suppress a decrease in the dimensional accuracy of the body.

Moreover, in the method for manufacturing a ceramic composite of the present invention , the first temperature is lower than or equal to the second temperature.

As a result , the first ceramic member made of the ceramic sintered body does not shrink in the heat treatment process, so that the difference in shrinkage rate in the heat treatment process can be further increased, and the composition of the ceramic composite can be diversified. becomes possible.

A first ceramic composite of the present invention comprises a first ceramic sintered body and a second ceramic sintered body having an internal space communicating with the outside through a first opening and a second opening , A ceramic composite functioning as a check valve , wherein at least part of the first ceramic sintered body is positioned within the internal space of the second ceramic sintered body, and the first The ceramic sintered body and the second ceramic sintered body are displaceable and inseparable from each other, the main components of the first and second ceramic sintered bodies are the same, and the first ceramic sintered body is The average grain size of the main component of the ceramic sintered body is equal to or larger than the average grain size of the main component of the second ceramic sintered body.

According to the first ceramic composite of the present invention, it is possible to obtain a ceramic composite having a structure that cannot be obtained in Patent Documents 1 and 2 above. The main components of the first and second ceramic sintered bodies are the same, and the average particle size of the main component of the first ceramic sintered body is the average particle size of the main component of the second ceramic sintered body. That's it. This makes it possible to bring about a difference in contraction rate between the ceramic members that will become the first and second ceramic sintered bodies during firing for producing the ceramic composite.

A second ceramic composite of the present invention includes a first ceramic sintered body and a second ceramic sintered body having an internal space communicating with the outside through an opening , and functions as a universal joint. Only a part of the first ceramic sintered body is located in the internal space of the second ceramic sintered body, and the first ceramic sintered body and the second ceramic sintered body are separated from each other. The ceramic sintered bodies are displaceable and inseparable from each other, the main components of the first and second ceramic sintered bodies are the same, and the purity of the main components of the first ceramic sintered body is higher than the purity of the main component of the second ceramic sintered body.

According to the second ceramic composite of the present invention, it is possible to obtain a ceramic composite having a structure that cannot be obtained in Patent Documents 1 and 2 above. The main components of the first and second ceramic sintered bodies are the same, and the purity of the main component of the first ceramic sintered body is higher than that of the second ceramic sintered body. In general, a ceramic molded body that becomes a ceramic sintered body has a lower firing temperature for densification due to the inclusion of a sintering aid. That is, the higher the purity, the higher the firing temperature. This makes it possible to bring about a difference in contraction rate between the ceramic members that will become the first and second ceramic sintered bodies during firing for producing the ceramic composite.

1 is a schematic perspective view of a ceramic composite according to a first embodiment of the present invention; FIG. FIG. 2 is a schematic cross-sectional view taken along line II-II of the ceramic composite according to the first embodiment; FIG. 4 is a schematic perspective view of a ceramic composite according to a second embodiment of the present invention; FIG. 4 is a schematic cross-sectional view taken along line IV-IV of the ceramic composite according to the second embodiment; 1 is a flow chart showing a method for manufacturing a ceramic composite according to an embodiment of the present invention; 1 is a schematic longitudinal sectional view of first and second ceramic members according to a first embodiment of the present invention; FIG. FIG. 5 is a schematic longitudinal sectional view of first and second ceramic members according to a second embodiment of the present invention;

A ceramic composite 100 and a method for manufacturing the same according to an embodiment of the present invention will be described with reference to the drawings. In each drawing, in order to clarify the configuration of the ceramic composite 100, each constituent element is deformed and does not represent an actual ratio.

1 to 4, a ceramics composite 100 according to an embodiment of the present invention includes a first ceramics sintered body 10 and a second ceramics sintered body 10 having an internal space 22 communicating with the outside through openings 21 and 24. and a ceramic sintered body 20 of.

At least a portion of the first ceramic sintered body 10 is positioned within an internal space 22 that is inserted through the openings 21 and 24 of the second ceramic sintered body 20 to the outside. The first ceramic sintered body 10 and the second ceramic sintered body 20 are displaceable relative to each other and cannot be separated.

In the first embodiment, referring to FIGS. 1 and 2, the first ceramic sintered body 10 is wholly located within the internal space 22 . More specifically, the first ceramic sintered body 10 is a sphere with a diameter M1. The second ceramic sintered body 20 has a rectangular parallelepiped outer shape and has a spherical internal space 22 with a diameter N1. The second ceramics sintered body 20 is formed with a cylindrical opening 21 having a circular cross section with a diameter P1 which opens in one outer surface and communicates the outside with the internal space 22 . In the second ceramic sintered body 20, there are also formed four cylindrical openings 23 having a circular cross section with a diameter Q1 that open to the other outer surface and communicate the interior space 22 with the exterior.

Here, diameter M1 is smaller than diameter N1 and larger than diameter P1 and diameter Q1. As a result, the first ceramic sintered body 10 is entirely positioned within the internal space 22 of the second ceramic sintered body 20, and the first ceramic sintered body 10 and the second ceramic sintered body are separated from each other. 20 are displaceable with respect to each other, but inseparable. That is, the movement of the first ceramic sintered body 10 from the internal space 22 to the outside is restricted by the second ceramics sintered body 20 .

In the second embodiment, with reference to FIGS. 3 and 4, only a portion of the first ceramic sintered body 10 is positioned within the internal space 22 . More specifically, the first ceramic sintered body 10 has a shape in which a spherical portion 11 having a diameter M1 and a cylindrical portion 12 are integrated. The second ceramic sintered body 20 has a rectangular parallelepiped outer shape and has a spherical internal space 22 with a diameter N1. The second ceramics sintered body 20 is formed with a tapered opening 24 having a circular cross section with a diameter S1 at the narrowest portion communicating with the inner space 22 with its one outer surface.

Here, diameter M1 is smaller than diameter N1 and larger than diameter S1. As a result, the spherical portion 11 of the first ceramic sintered body 10 is positioned within the internal space 22 of the second ceramic sintered body 20, and the first ceramic sintered body 10 and the second ceramics sintered body are separated from each other. The sintered body 20 can be displaced with respect to each other, but is inseparable. That is, movement of the spherical portion 11 from the internal space 22 to the outside is restricted by the second ceramic sintered body 20 .

For example, the first and second ceramic sintered bodies 10 and 20 have the same main component of the ceramic material, and the average particle diameter of the main component of the ceramic material of the first ceramic sintered body 10 is It is equal to or larger than the average grain size of the main component of the ceramic material of the second ceramic sintered body 20 . Here, the average particle size of the main component of the ceramic material of the first and second ceramic sintered bodies 10 and 20 was obtained by polishing the first and second ceramic sintered bodies 10 and 20 and using a scanning electron microscope. An arbitrary 30 μm square area in the photograph of the field of view expanded 2000 times to 5000 times using the method is binarized by image processing software such as Image-J, and the equivalent circle diameter of all grain sizes is calculated and obtained. Alternatively, it can be measured using a method of calculation using an intercept method for an arbitrary 30 μm square area after polishing.

Alternatively, the main components of the ceramic material of the first and second ceramic sintered bodies 10 and 20 are the same, and the purity of the main component of the ceramic material of the first ceramic sintered body 10 is the second ceramic sintered body. higher than the purity of the main component of the body 20; Here, the purities of the first and second ceramic sintered bodies 10 and 20 are measured using known techniques such as quantitative determination using an energy dispersive SEM, ICP emission spectrometry, or ICP mass spectrometry. be able to.

However, the relationship between the ceramic materials of the first and second ceramic sintered bodies 10 and 20 is not limited to that described above. For example, the first and second ceramic sintered bodies 10 and 20 may have the same or different main components, purity, and average grain size of the ceramic material.

As the ceramic material, for example, alumina (aluminum oxide), aluminum nitride, silicon nitride, or the like can be used. For example, when alumina with a purity of 99.5% by weight is used as the material for the first ceramic sintered body 10, alumina with a purity of 99.99% by weight and a purity of 99.9% are used as the material for the second ceramics sintered body 20. It is preferable to use 5% by weight alumina or 95% by weight purity alumina added with SiO ₂ —CaO—MgO as a sintering aid.

A method for manufacturing a ceramic composite 100 according to an embodiment of the present invention will be described below with reference to the drawings.

5 to 7, this manufacturing method includes a first ceramic member preparing step S10 of preparing a first ceramic member 30 made of a first ceramic, and a second ceramic member 30 made of a second ceramic. a second ceramic member preparing step S20 for preparing the member 40; an inserting step S30 for inserting at least a portion of the first ceramic member 30 into the internal space S of the second ceramic member 40; and a heat treatment step S40 for heat-treating the ceramic members 30 and 40.

In the first ceramic member preparation step S10, a ceramic raw material is molded to obtain a ceramic molded body in a molding step S11, and the ceramic molded body is heat-treated at a second temperature T2 to obtain a ceramic sintered body or a ceramic temporary body. It is preferable to include a heat treatment step S12 for obtaining the first ceramic member 30 made of a sintered body.

At this time, the first temperature T1, which is the heating temperature in the heat treatment step S40, must be lower than or equal to the second temperature T2, which is the heating temperature when the ceramic compact is heat-treated to obtain the first ceramic member 30. is preferred. Also, the ceramic molded body is preferably produced by molding a ceramic raw material by a cold isostatic pressing method, an injection molding method, or a casting method. However, the ceramic molded body may be produced by a molding method other than this.

Furthermore, the second ceramics member 40 may be a ceramics molded body that is not heat-treated after molding the ceramics raw material.

In the second ceramics member preparation step S20, the second ceramics member 40 is made of the second ceramics and has an internal space 42 communicating with the outside through the openings 41 and 43, and is made of the second ceramics member 40 at the first temperature. A second ceramic member 40 having a shrinkage rate larger than that of the ceramic member 30 is prepared.

In the first embodiment, referring to FIG. 6, specifically, the first ceramics member 30 is a sphere with a diameter of M2, and the second ceramics member 40 has a rectangular parallelepiped outer shape. The second ceramics member 40 is formed with a cylindrical opening 41 having a circular cross-section with a diameter P2 which is open on one outer surface and penetrates the outside and the inner space 42 . The second ceramic member 40 is also formed with four cylindrical openings 43 having a circular cross-section with a diameter Q2 that open to the other outer surface and communicate the interior space 42 with the exterior.

Here, diameter M2 is smaller than diameter N2 and diameter P2 and larger than diameter Q2. As a result, the first ceramic member 30 as a whole can be inserted through the opening 41 into the internal space 42 of the second ceramic member 40 .

In the second embodiment, referring to FIG. 7, specifically, a first ceramic member 30 is formed by integrating a spherical portion 31 having a diameter of M2 and a cylindrical portion 32. The second ceramic member 40 has a rectangular parallelepiped outer shape. The second ceramics member 40 is formed with a tapered opening 44 having a circular diameter S2 at its narrowest portion which is open on one outer surface and communicates the outside with the internal space 42 .

Here, diameter M2 is smaller than diameter N2 and diameter S2. Thereby, the spherical portion 31 of the first ceramics member 30 can be inserted into the internal space 42 of the second ceramics member 40 through the opening 44 .

The first ceramics and the second ceramics are different. For example, the first ceramics and the second ceramics are different in the type of ceramics as the main raw material, or different in average particle size, or the addition ratio of the auxiliary raw materials such as sintering aids and binders. different.

When the first ceramic member 30 is a sintered body, the second ceramic member 40 is preferably a ceramic compact or a calcined body. When the first ceramic member 30 is a calcined body, The second ceramic member 40 is preferably a ceramic compact.

Furthermore, both the first and second ceramic members 30 and 40 may be ceramic compacts. In this case, the shrinkage rate of the second ceramic member 40 should be larger than the shrinkage rate of the first ceramic member 30 when the heat treatment is performed at the first temperature T1 in the heat treatment step S40.

The ceramic compacts to be the first and second ceramic members 30 and 40 are preferably produced by molding ceramic raw materials by cold isostatic pressing, injection molding, or casting. As a result, variations in the density of the ceramic molded body can be suppressed compared to those molded by a uniaxial pressing method or the like. However, ceramic compacts to be the first and second ceramic members 30 and 40 may be produced by a molding method such as a uniaxial pressing method.

In the inserting step S<b>30 , at least part of the first ceramics member 30 is inserted into the internal space 42 through the openings 41 and 43 . The first ceramic member 30 may be entirely inserted into the internal space 42 or may be partially inserted into the internal space 42 . In order to insert at least part of the first ceramics member 30 into the internal space 42, the shape allows the portion of the first ceramics member 30 to be inserted into the internal space 42 to freely pass through the opening 41. It has become.

In the heat treatment step S40, the first and second ceramic members 30, 40 are heat-treated at a first temperature while at least part of the first ceramic member 30 is inserted into the internal space 42. 1 to 4, a first ceramic sintered body 10 obtained by heat-treating a first ceramic member 30, and a second ceramic sintered body 10 obtained by heat-treating a second ceramic member 40. A ceramic composite 100 is obtained in which the joint 20 is displaceable and inseparable from each other.

In addition, for example, the first ceramic member 30 is made of a ceramic sintered body containing alumina as a main component, and the purity of the alumina as the ceramic raw material is 99.5% by weight and the average particle diameter is about 0.6 μm. When the average particle diameter of alumina after firing is about 4 μm, the firing temperature at which the ceramic raw material becomes dense is about 1600°C. On the other hand, the second ceramic member 40 is made of the same ceramic raw material as the first ceramic member 30, and the average particle size of alumina obtained when this is fired at 1580° C. is about 3 μm. Further, when the second ceramic member 40 is made of a ceramic raw material mainly composed of alumina having a first purity of about 95% by weight and an average particle diameter of about 1.8 μm, the firing temperature at which the ceramic raw material is densified is It becomes about 1500°C.

Thus, when the ceramic material is the same, the higher the firing temperature, the larger the average particle size of the ceramic sintered body. When the ceramic material is different, the higher the purity, the higher the firing temperature. The average particle size of the body increases. Further, when the main components of the ceramic raw material are the same, the higher the purity of the main component, the higher the firing temperature required to densify the sintered body.

In the heat treatment step S40, by heat-treating the first and second ceramic members 30, 40 at the first temperature T1, the second ceramic member 40 has a larger shrinkage rate than the first ceramic member 30. The contraction prevents the portion inserted into the internal space 42 from slipping out through the openings 41 and 43. - 特許庁As a result, the first ceramic sintered body 10 obtained by heat-treating the first ceramic member 30 and the second ceramic sintered body 20 obtained by heat-treating the second ceramic member 40 are placed against each other. A ceramic composite 100 is obtained that is displaceable and non-separable.

The ceramic composite produced by the method for producing a ceramic composite of the present invention is not limited to the ceramic composite of the present invention. The ceramic composite 100 and the method for producing the same of the present invention are not limited to those described above. For example, the ceramic composite of the present invention is not limited to the ceramic composite 100 according to the first or second embodiment, and if it functions as a check valve or a universal joint, its configuration, shape, material, etc. are also limited. not.

(Example 1)
Referring to FIG. 6, alumina (Al ₂ O ₃ ) with a purity of 99.5% by weight is used as a ceramic raw material, and a PVA binder of 5% by weight or less is added to granulate. A mold was filled to form a spherical ceramic compact. Then, this spherical ceramic molded body was sintered by holding it at 1600° C. for 3 hours in an atmospheric atmosphere in the furnace. Then, the surface of the obtained sintered body was processed to obtain a spherical ceramic sintered body having a diameter M of 20 mm as the first ceramic member 30 . The average particle size of alumina in this ceramic sintered body was 4 μm.

Using the granulated powder, a cube having a side of 60 mm was obtained by cold isostatic pressing. An opening 41 with a diameter P of 21 mm was formed on one face of the cube, and a spherical internal space 42 with a diameter N of 40 mm was formed in the center of the cube through this hole. Furthermore, four openings 43 each having a diameter Q2 of 5 mm were formed on the other face of the cube so as to reach the internal space 43 . Thus, a second ceramic member 40 was obtained.

The first and second ceramic members 30, 40 were placed in a furnace with the entire first ceramic member 30 positioned in the internal space 42, and held at 1580° C. for 3 hours in an atmospheric atmosphere in the furnace. and baked. At this time, the first ceramics member 30 was supported by a supporting member (not shown) so that the first ceramics member 30 and the second ceramics member 40 would not come into contact with each other.

As a result of the sintering, referring to FIGS. 1 and 2, the first ceramics member 30 became the first ceramics sintered body 10 without changing its shape, size, composition, and the like. On the other hand, the second ceramic member 40 has a cubic outer shape with one side of 49.6 mm, the internal space 42 has a spherical shape with a diameter N1 of 33 mm, and the opening 21 has a diameter P1 of 17.4 mm and four Aperture 22 has shrunk to a diameter Q1 of 4.1 mm. As a result, the first ceramics sintered body 10 is entirely positioned within the internal space 22, and the first ceramics sintered body 10 is prevented from coming out of the opening 21, thereby separating the first ceramics sintered body 10 and the second ceramics sintered body 10 from the second ceramics sintered body 10. A ceramic composite 100 was obtained which was inseparable from the ceramic sintered body 20 of . The average particle size of alumina in the second ceramic sintered body 20 was 3 μm.

Furthermore, when water is allowed to flow into the internal space 22 through the openings 21, the first ceramic sintered body 10 moves inward, but the four openings 23 are not closed, and the water flows through the openings 23. was confirmed to flow out. On the other hand, it was confirmed that when water was allowed to flow into the internal space 22 from the opening 23, the first ceramic sintered body 10 moved inward and blocked the opening 21, and water did not flow out through the opening 21. rice field. From this, it was found that the ceramic composite 100 can function as a check valve.

(Example 2)
Referring to FIG. 7, alumina (Al ₂ O ₃ ) having a purity of 99.5% by weight is used as a ceramic raw material, and a PVA binder of 5% by weight or less is added to granulate. A ceramic compact ingot formed by hydrostatic pressing was processed to obtain a ceramic compact in which a spherical ceramic compact and a cylindrical ceramic compact were connected. Then, this ceramic molded body was sintered by holding it at 1600° C. for 3 hours in an atmospheric atmosphere in the furnace.

Then, the surface of the obtained sintered body is processed to integrate a spherical ceramic sintered body 31 having a diameter N2 of 20 mm and a columnar ceramic sintered body 32 having a diameter of 10 mm and a length of 60 mm. was obtained.

A cube having a side of 60 mm was obtained by cold isostatic pressing using the granulated powder. A tapered opening 44 was formed in one face of the cube, and through this opening 44, a spherical internal space 42 with a diameter N2 of 24.5 mm was formed in the center of the cube. As a result, the diameter S2 of the narrowest portion of the tapered opening 44 was 21 mm. Thus, a second ceramic member 40 was obtained.

With only the spherical portion 31 of the first ceramics member 30 positioned in the internal space 42, the first and second ceramics members 30, 40 were placed in a furnace and heated at 1600° C. with an atmospheric atmosphere in the furnace. It was baked by holding for 3 hours. At this time, the first ceramics member 30 was supported by a supporting member (not shown) so that the first ceramics member 30 and the second ceramics member 40 would not come into contact with each other.

As a result of firing, the first ceramics member 30 became the first ceramics fired body 10 as it was without changing its shape, size, composition, and the like. On the other hand, the second ceramic member 40 has a cubic outer shape with one side of 49.6 mm, the internal space 22 is spherical with a diameter N1 of 20.2 mm, and the diameter S1 of the narrowest part of the opening 24 is 17.6 mm. It was shrunk to 4 mm. As a result, the spherical portion 11 of the first ceramics sintered body 10 is positioned within the internal space 22, the first ceramics sintered body 10 cannot escape from the opening 24, and the first ceramics sintered body 10 and the second ceramics sintered body A ceramic composite 100 was obtained in which the ceramic sintered body 20 of No. 2 could not be separated.

Furthermore, the gap between the spherical portion 11 of the first ceramics sintered body 10 and the inner surface of the internal space 22 is 0.2 mm throughout, and the first ceramics sintered body 10 does not rattle. , it was confirmed that the second ceramic sintered body 20 can slide and rotate satisfactorily. As a result, it was found that the ceramic composite 100 can function as a universal joint.

DESCRIPTION OF SYMBOLS 10... First ceramic sintered body 11... Spherical portion 12... Cylindrical portion 20... Second ceramic sintered body 21... Opening 22... Internal space 23... Opening 30... First first ceramic sintered body 31... Spherical portion 32... Cylindrical portion 40... Second ceramic member 41... Opening 42... Internal space 43... Opening.

Claims (5)

obtaining a first ceramic member made of a ceramic sintered body or a ceramic calcined body by heat-treating the ceramic compact at a second temperature;
A second ceramic member comprising a ceramic molded body that has not been heat-treated after molding a ceramic raw material, and has an internal space that communicates with the outside through a first opening and a second opening that is smaller than the first opening. preparing a second ceramic member having a larger shrinkage rate than the first ceramic member at a first temperature;
an inserting step of inserting at least part of the first ceramic member into the internal space through the first opening;
a first ceramic sintered body, which is the heat-treated first ceramic member, by heat-treating the first and second ceramic members at the first temperature in the inserted state; a heat treatment step in which the second ceramic sintered body, which is the heat-treated second ceramic member , becomes displaceable and inseparable from each other to obtain a ceramic composite functioning as a check valve ; with
the first temperature is less than or equal to the second temperature;
The primary components of the first and second ceramic sintered bodies are the same, and the purity of the primary component of the first ceramic sintered body is higher than the purity of the primary component of the second ceramic sintered body. A method for producing a ceramic composite, characterized by: obtaining a first ceramic member made of a ceramic sintered body or a ceramic calcined body by heat-treating the ceramic compact at a second temperature;
A second ceramic member comprising a ceramic molded body that has not been heat-treated after molding a ceramic raw material and has an internal space that communicates with the outside through an opening, wherein the second ceramic member has a higher temperature than the first ceramic member at a first temperature. preparing a second ceramic member having a large shrinkage rate;
an inserting step of inserting only a portion of the first ceramic member into the internal space through the opening;
a first ceramic sintered body, which is the heat-treated first ceramic member, by heat-treating the first and second ceramic members at the first temperature in the inserted state; a heat treatment step in which the second ceramic sintered body, which is the heat-treated second ceramic member, becomes displaceable and inseparable from each other to obtain a ceramic composite functioning as a universal joint;
the first temperature is less than or equal to the second temperature;
The primary components of the first and second ceramic sintered bodies are the same, and the purity of the primary component of the first ceramic sintered body is higher than the purity of the primary component of the second ceramic sintered body. A method for producing a ceramic composite, characterized by: a step of forming the ceramics raw material by any one of cold isostatic pressing, injection molding, and casting to produce the ceramics compact that constitutes the second ceramics member; 3. The method for producing a ceramic composite according to claim 1, comprising: A ceramic composite functioning as a check valve, comprising a first ceramic sintered body and a second ceramic sintered body having an internal space communicating with the outside through a first opening and a second opening. hand,
At least a portion of the first ceramic sintered body is positioned within the internal space of the second ceramic sintered body, and the first ceramic sintered body and the second ceramic sintered body are separated from each other. are displaceable and inseparable with respect to each other, and
The main components of the first and second ceramic sintered bodies are the same, and the average particle size of the main component of the first ceramic sintered body is the average particle size of the main component of the second ceramic sintered body. A ceramic composite having a diameter equal to or larger than the diameter. A ceramic composite functioning as a universal joint, comprising a first ceramic sintered body and a second ceramic sintered body having an internal space communicating with the outside through an opening,
Only a part of the first ceramic sintered body is located in the internal space of the second ceramic sintered body, and the first ceramic sintered body and the second ceramic sintered body are separated from each other. are displaceable and inseparable with respect to each other, and
The primary components of the first and second ceramic sintered bodies are the same, and the purity of the primary component of the first ceramic sintered body is higher than the purity of the primary component of the second ceramic sintered body. A ceramics composite characterized by:

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