JP2878923B2 - Manufacturing method of ceramic joined body - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a joined body of a ceramic porous plate and a ceramic tubular body.

[0002]

2. Description of the Related Art Ceramics have a high degree of heat and heat insulation irrespective of the composition of oxides and non-oxides, and have electrical and electronic properties such as insulation, conductivity, magnetic and dielectric properties. It has a function and also has excellent mechanical properties such as abrasion resistance, and has already been used as a material for various structures and has been researched and developed. When ceramics are used as mechanical part materials or structural materials, mechanical parts and structural members of various shapes are required, and combinations of parts and members are also required. As a result, it is necessary to bond and fix ceramics in all parts.

[0003] Among various components and members, a joined body in which a plate-shaped member and a member having another shape are combined is often used as a mechanical part or a structural member, and is formed by drilling a plurality of holes in a flat plate and penetrating and fixing a tubular body. There are many examples of use. For example, in a ceramic heat exchanger of an industrial furnace as disclosed in Japanese Patent Application Laid-Open No. 60-62592 by the applicant, a member in which a number of ceramic tubular bodies are fixed to a plate-like body is used.

As described above, many attempts have been made to apply ceramics as parts and members of a heat exchanger. As a method of inserting and fixing a ceramic tubular body into a hole formed in a ceramic plate-like body, there are several methods. A porous plate, which is a ceramic unsintered body having perforated holes, and a tubular body, which is a ceramic sintered body, are heated and fired in a state where the tubular body is inserted into each of the perforated holes of the perforated plate. There is known a method of integrally joining by utilizing a difference in shrinkage. In this method, a tubular body made of a sintered body having a small firing shrinkage and hardly shrinking is shrunk by firing shrinkage of perforated holes formed in a perforated plate made of an unsintered body having a large firing shrinkage. , Both will be integrated.

[0005]

However, in the above method, a central portion of the perforated plate 1 where a plurality of perforations 3 are formed as shown in FIG. There is a problem that a difference in firing shrinkage ratio occurs between the non-collar portion 5 and the brim portion 5, which causes a crack in the porous plate.
That is, the firing shrinkage of the perforated hole formed in the perforated plate is partially hindered by the tubular body inserted into the perforated hole. The stress becomes smaller than the brim portion, and the stress generated inside the perforated plate due to the difference in firing shrinkage causes cracks in the perforated plate and deterioration in the airtightness of the joint.

[0006] The present invention has been made in view of such problems of the prior art.
In the production of a joined body of a ceramic porous plate and a ceramic tubular body using the difference in firing shrinkage, the difference in firing shrinkage between the perforated hole forming portion of the porous plate and the surrounding brim portion is reduced, and cracks in the porous plate are reduced. An object of the present invention is to provide a method for manufacturing an excellent joined body without deterioration of the airtightness of a joined portion.

[0007]

In order to achieve the above object,
According to the present invention, a porous plate that is a ceramic unsintered body having a plurality of perforated holes, and a tubular body that is a ceramic sintered body, and the tubular body is inserted into each perforated hole of the perforated plate. In the method for producing a ceramic joined body, which is heated and fired in a state, and is integrally joined by utilizing a difference in firing shrinkage between the two, a hole diameter of the perforated hole is formed at a collar portion around a perforated hole forming portion of the perforated plate. A dummy hole having a diameter equal to that of the tubular body is provided, and a pin-shaped ceramic sintered body having substantially the same outer diameter and firing shrinkage as the tubular body is inserted into the dummy hole, followed by heating and firing, and integrally joining. The present invention provides a method for manufacturing a ceramic joined body characterized by the following.

[0008]

The present invention is constructed as described above. As shown in FIG. 1, a dummy hole 4 is provided in a flange portion 5 of a perforated plate 1 and a pin-shaped ceramic sintered body 6 is inserted into the hole. By firing, like the drilled hole in which the tubular body was inserted,
The firing shrinkage of the dummy hole 4 is reduced to a pin-shaped ceramic sintered body 6.
Will be hindered in part. In this case, the hole diameter 4 of the dummy hole and the hole diameter of the perforated hole 3 into which the tubular body is inserted are equal, and the outer diameter and the firing shrinkage of the pin-shaped ceramic sintered body 6 and the tubular body are almost the same. Since they are equal, the difference in the firing shrinkage between the perforated hole forming portion of the perforated plate 1 and the brim portion 5 is eliminated or extremely small. Therefore, the stress inside the perforated plate due to the difference in firing shrinkage between the perforated hole forming portion and the brim portion is also eliminated,
An excellent joined body free from cracks in the perforated plate and deterioration in the airtightness of the joint is obtained.

As the ceramics used in the present invention, any ceramics such as oxide and non-oxide compounds may be used. May be selected as appropriate. For example, when used for engines, industrial machines, heat exchangers, etc., silicon nitride or silicon carbide having high strength and high heat resistance is used. The perforated plate and the tubular body are usually made of the same type of ceramics. The shape, thickness and size of the perforated plate are not particularly limited, and may be selected according to the purpose of use and conditions. The number of holes, the shape of holes and the arrangement of holes are not particularly limited, and the shape of a tubular body to be inserted,
It may be determined according to the size and the number of insertions.

The perforated hole and the dummy hole of the perforated plate may be provided at the same time as forming the plate-shaped body having the basic shape of the perforated plate, or may be formed by punching or ultrasonic processing after forming. Is also good. The pin-shaped ceramic sintered body is required to have a firing shrinkage rate substantially equal to the firing shrinkage rate of the tubular body, and is usually preferably a sintered body of the same type of ceramic as the tubular body.

[0011]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

(Example) To 1000 g of silicon nitride powder, 10 g of Y ₂ O _3, 10 g of MgO, and ZrO ₃ 5 as sintering aids
g, 1 g of polyvinyl alcohol as an organic binder, and 1000 g of water,
mm) using an attritor for 4 hours. The obtained finely pulverized mixture was dried and granulated by a spray drier, and a powder was obtained as a raw material, a tubular molded body was produced by extrusion molding, and dried at 110 ° C. for 10 hours. After drying, calcinate the binder at 500 ° C for 5 hours,
Baking at 1650 ° C for 1 hour, outer diameter 8mm, inner diameter 6m
m, a tubular body having a length of 300 mm was obtained.

Further, a plate-like molded body was produced by applying a pressure of 7 ton / cm ² by isostatic pressing using the same raw materials as those used for producing the tubular body. This was dried and calcined under the same conditions as in the production of the tubular body, and calcined at 1350 ° C. for 3 hours in a nitrogen atmosphere. A plurality of perforated holes having a hole diameter of 9.3 mm for inserting and joining a tubular body were formed by ultrasonic processing on the obtained calcined body having a size of 350 × 170 mm and a thickness of 20 mm. Drill a 9.3mm diameter hole in the same part,
A perforated plate was obtained.

Next, as shown in FIG. 1, a silicon nitride sintered pin 6 having an outer diameter of 8 mm is inserted into each dummy hole 4 formed in the flange portion 5 of the perforated plate 1, and is inserted into the other perforated holes 3. Is inserted into each of the tubular bodies so that the ends thereof coincide with one surface of the perforated plate 1, and heated and fired at 1650 ° C. for 3 hours in a nitrogen atmosphere to be joined and integrated to form a tubular body 2 as shown in FIG. A ceramic joined body in which the porous plate 1 was joined to the upper and lower ends of the ceramic body was obtained. Note that the interference of the firing bonding was 0.2 mm.

No crack in the perforated plate was observed in the obtained ceramic joined body. Further, a sample in which only one of the upper end and the lower end of the porous body was joined to one tubular body was cut out from the ceramic joined body, and FIG.
The airtightness of the joint was examined using an airtightness test apparatus shown in FIG. In FIG. 3, the sample 11 is held by a holding jig 7 installed in a water tank 8, and the space between the holding jig 7 and the sample 11 is sealed by an O-ring 9. Then, in this state, 7 kg / cm ² of air was loaded through the air passage 10 to examine the presence or absence of air leakage from the joint. No leakage was found.

(Comparative Example) As shown in FIG. 4, only a perforated hole 3 for inserting and joining a tubular body into a perforated plate 1 is formed.
A ceramic joined body was produced in the same manner as in the above example, except that no dummy hole was formed in the brim portion 5.
Cracks occurred in the perforated plate. In addition, about this joint,
As a result of examining the airtightness of the joint in the same manner as in the example, a considerable amount of air leakage was observed.

[0017]

As described above, according to the present invention,
In the production of a joined body of a ceramic porous plate and a ceramic tubular body using the difference in firing shrinkage, the difference in firing shrinkage between the perforated hole forming portion of the porous plate and the surrounding brim portion is reduced, and cracks in the porous plate are reduced. An excellent joined body without deterioration of the airtightness of the joined portion can be manufactured.

[Brief description of the drawings]

FIG. 1 is an explanatory plan view of a perforated plate having dummy holes used in the manufacturing method of the present invention.

FIG. 2 is an explanatory side view showing an example of a ceramic joined body obtained by the manufacturing method of the present invention.

FIG. 3 is an explanatory view showing an airtightness test device.

FIG. 4 is an explanatory plan view of a perforated plate used in a conventional method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Perforated plate 2 Tubular body 3 Drilling hole 4 Dummy hole 5 Flange part 6 Pin-shaped ceramics sintered body 7 Holding jig 8 Water tank 9 O-ring 10 Air passage 11 Sample

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) C04B 37/00 B28B 11/02

Claims (1)

(57) [Claims] 1. A state in which a porous plate which is a ceramic unsintered body having a plurality of perforated holes and a tubular body which is a ceramic sintered body are inserted into each perforated hole of the perforated plate. In the method for manufacturing a ceramic joined body integrally joined by utilizing the difference in firing shrinkage between the two, the hole diameter of the perforated hole and the diameter of the perforated hole around the perforated hole forming portion of the perforated plate Providing a dummy hole having an equal hole diameter, heating and firing in a state in which a pin-shaped ceramic sintered body having an outer diameter and a firing shrinkage ratio substantially equal to the tubular body is inserted into the dummy hole, and integrally joining. Characteristic method of manufacturing a ceramic joined body.