JPH11130554A - Joined structure of ceramic raw materials - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joined structure of ceramic raw materials, not generating cracks on the joined interface and strongly joining both the ceramic raw materials to each other by disposing an adhesive reservoir or an air vent groove on the surface of either of the depressed portion of the first ceramic raw material and the projected portion of the second ceramic raw material, when the projected portion of the second ceramic raw material is fit into the depressed portion of the first ceramic raw material through a joining agent. SOLUTION: This joined structure of ceramic raw materials is obtained by fitting the projected pin 3 of the second ceramic raw material 3 into the depressed fitting hole 4 of the first ceramic plate raw material 2 through a ceramic joining agent, and subsequently calcining the joined product. The ceramic pin 3 is provided with an air vent groove 7. The air vent groove is single, and disposed in such a length as its one end is exposed to the upper surface. The ceramic joining agent comprises the powder of the same ceramic as that of the ceramic raw material, a binder and water, and is coated on the joining surface and subsequently calcined. The formation of plural grooves not parallel to the insertion direction on the joining surface can enlarge the joining strength.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic material joining structure.

[0002]

2. Description of the Related Art Ceramic structural materials are excellent in heat resistance and corrosion resistance and are used as various jigs. However, ceramics are difficult to process and it is difficult to integrally manufacture jigs having complicated shapes. Therefore, a material obtained by combining and joining partially manufactured materials is used.

FIG. 5 shows an example of a joining structure. The ceramic plate 22 is provided with a pin fitting hole 24 as a concave portion, and a ceramic pin 23 as a convex portion is fitted into the pin fitting hole 24. The pin insertion hole 24 is a large diameter portion 24
a and a small-diameter portion 24b, and the boundary between the two 24a and 24b is a step. In FIG. 5, the side with the large diameter portion 24a is the upper side. The ceramic pin 23 has a substantially cylindrical shape, and a circular convex portion 26 is formed on an end face on the lower half portion 25 side. The lower half portion 25 of the ceramic pin 23 as the fitting portion is joined via a ceramic joining agent in a state of being fitted into the pin fitting hole 24.

[0004] The joining structure 21 having such a configuration is manufactured, for example, in the following procedure. First, a plate-shaped molded body and a pin-shaped molded body are produced, respectively, and they are calcined at a predetermined temperature. As a result, the ceramic plate 22 and the ceramic pins 23 which have been sintered to some extent are obtained. Next, the pin fitting holes 24 are formed in the ceramic plate 22.
And the projections 2 are formed on the ceramic pins 23.
6 is formed. Then, a ceramic bonding agent prepared in advance is applied, and in this state, the ceramic pin 23 is fitted into the pin fitting hole 24. After such assembling work is completed, firing is performed again. Then, as a result of sintering the ceramic plate 22, the ceramic pin 23, and the ceramic bonding agent together, the connection structure 2 in which the ceramic plate 22 and the ceramic pin 23 are bonded and integrated.
1 is obtained.

[0005]

However, in the prior art, the strength of the joint between the ceramic plate 22 and the ceramic pin 23 was low. For this reason, when a large load or impact is applied to the joint portion, cracks occur at the interface of the joint portion, and there is a problem that the ceramic pin 23 easily comes off from the pin fitting hole 24. Therefore, a high-strength joint structure 21 could not be realized.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a joining structure of a ceramic material having excellent joining strength.

[0007]

According to the first aspect of the present invention, a concave portion provided on a first ceramic material and a convex portion provided on a second ceramic material are provided. And a fitting structure in which the fitting portion is bonded via a bonding agent, wherein a groove is formed on at least one surface of the concave portion and the convex portion of the fitting portion. The gist is a joining structure of ceramic materials.

[0008] In the invention described in claim 2, in claim 1, the groove is a bonding agent accumulation groove formed so as not to be parallel to the fitting direction of the fitting portion of the ceramic material. According to a third aspect of the present invention, in the first aspect, the groove is an air vent groove continuously provided to a non-fitting portion of the ceramic material.

Hereinafter, the "action" of the present invention will be described. According to the first to third aspects of the present invention, since the grooves are formed, an appropriate amount of the bonding agent can be held at the interface between the two ceramic materials. Therefore, both ceramic materials can be joined more firmly.

[0010] According to the second aspect of the present invention, since the bonding agent reservoir groove is formed, the two ceramic materials can be more firmly bonded to each other by the anchor effect due to the bonding agent being buried in the groove. it can.

According to the third aspect of the present invention, when the ceramic material is fitted, the air left in the fitting portion is sent out along the air vent groove, so that the bonding agent at the fitting portion is air-filled. It is not extruded. For this reason, a bonding agent is reliably present at the interface,
Both ceramic materials can be joined more firmly. In addition, when the above-mentioned bonding agent reservoir groove is formed in addition to this, since a synergistic action is exerted, the two are more strongly bonded.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment embodying a joining structure of a ceramic material according to the present invention will be described below in detail with reference to FIGS. 1 and 2 (a).

The joint structure 1 of the embodiment comprises a ceramic plate 2 as a first ceramic material and a ceramic pin 3 as a second ceramic material. FIG. 1 is a partially cutaway perspective view thereof, and FIG. 2 (a) is a partial sectional view in a joined state. At a plurality of locations of the ceramic plate 2, pin insertion holes 4 as recesses are provided. The pin insertion hole 4 has a circular cross section. Pin insertion hole 4
Is composed of a large diameter portion 4a and a small diameter portion 4b.
Border is a step. In FIGS. 1 and 2A, the side with the large diameter portion 4a is the upper side (pin insertion side). The ceramic pin 3 has a substantially cylindrical shape, and a circular convex portion 6 is formed on an end face on the lower half portion 5 side. The lower half 5 of the ceramic pin 3 is joined via a ceramic joining agent in a state of being fitted into the pin fitting hole 4.

The ceramic pin 3 has an air vent groove 7 as a groove. This air vent groove 7 is used for the ceramic pin 3
Are formed on the outer peripheral surface of. Here, the air vent groove 7 is 1
Only the book is formed parallel and linear to the fitting direction of the ceramic pin 3 (that is, the axial direction of the ceramic pin 3). The length of the air vent groove 7 is preferably set in advance so that one end thereof is partially exposed from the upper surface when completely inserted. That is, the air vent groove 7 is provided continuously to the non-fitting portion.

Ceramic plate 2 and ceramic pin 3
Can be obtained by preparing a plate-shaped molded body and a pin-shaped molded body, respectively, and calcining them at a predetermined temperature. As a starting material at that time, a material obtained by mixing a ceramic powder with a binder, a dispersant, and the like and kneading the mixture is used. Examples of the ceramic powder used include β-type silicon carbide powder, α-type silicon carbide powder, silicon nitride powder, aluminum nitride powder, boron nitride powder, zirconia powder, alumina powder, and mullite powder. The average particle size of the ceramic powder is about 0.10 μm to 0.50 μm,
Preferably, the thickness is about 0.15 μm to 0.30 μm.

For example, when silicon carbide powder is selected as the ceramic powder, the calcination temperature is 1500 ° C. to 2 ° C.
It is set to about 000 ° C. In the ceramic plate 2 and the ceramic pins 3 obtained by the preliminary firing, at least a region to be a bonding surface has a surface roughness (Rm
ax) is preferably 20 μm to 100 μm, and more preferably about 50 μm. This is because the bonding operation of the ceramic bonding agent can be maximized.

Thereafter, a pin insertion hole 4 is formed in a predetermined portion of the ceramic plate 2 by a drill or the like. A protrusion 6 is provided at one end of the ceramic pin 3.
The air vent groove 7 is formed on the outer peripheral surface of the lower half portion 5 by groove processing. The air vent groove 7 can be formed not only after the preliminary firing but also before the preliminary firing. However,
Since deformation due to heat during firing can be avoided, formation after preliminary firing is more preferable in that fine grooves can be accurately formed.

The air vent groove 7 has a depth of 0.1 mm.
２2 mm, preferably 0.5 mm０．５1.0 mm. If this depth is too shallow, the expected effect may not be sufficiently obtained. On the other hand, if this depth is too deep, it may lead to a cause of a decrease in strength of the ceramic materials 2 and 3.

Next, a ceramic bonding agent for bonding the ceramic plate 2 and the ceramic pin 3 will be described. The ceramic bonding agent used here is obtained by mixing and kneading a binder and water with ceramic powder.

As the ceramic powder, the above-listed β
Type silicon carbide powder, α-type silicon carbide powder, silicon nitride powder, aluminum nitride powder, boron nitride powder, zirconia powder, alumina powder, mullite powder, and the like. In this case, it is preferable that the same type of ceramic powder as that used for the ceramic plate 2 and the ceramic pin 3 is selected as the ceramic powder. This is because if they are of different types, the bonding strength may be reduced, or bonding may not be possible.

Further, as the ceramic powder, it is preferable to select a ceramic powder having the same average particle diameter as the ceramic powder constituting the ceramic plate 2 and the ceramic pins 3. By setting like this,
This is because a decrease in bonding strength can be prevented.

As the binder, an acrylic binder is used. In addition, for example, ethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, polyvinyl butyral, etc. are used. The binder is
0.5 parts by weight to 100 parts by weight of ceramic powder
About 5 parts by weight may be blended. This is because by setting the content in this range, a suitable viscosity as a bonding agent can be obtained.

In place of the water, an organic solvent such as α-terpineol, tetrahydrofuran or benzene may be blended as a dispersant. The water or dispersant, etc.,
30 parts by weight to 4 parts per 100 parts by weight of ceramic powder
It is preferable that about 0 parts by weight be blended.

[0024] The ceramic bonding agent is prepared by mixing and kneading the materials.
Preferably, it is sufficiently degassed during preparation. This is because such pretreatment surely has a positive effect on improving the bonding strength.

The ceramic bonding agent prepared as described above is applied to a bonding surface in advance before fitting. That is, it is applied to the inner wall surface of the pin insertion hole 4 of the ceramic plate 2 and the outer peripheral surface of the lower half portion 5 of the ceramic pin 3. The coating may be applied to both sides as described above, or may be applied to only one of the sides. However, in order to reliably supply the ceramic bonding agent, it is more preferable to adopt the former coating method.

Next, the lower half part 5 of the ceramic pin 3 is fitted into the pin fitting hole 4 from the upper opening. At this time, the air left in the fitting portion is sent out rearward (upward) along the air vent groove 7. This prevents the ceramic bonding agent in the fitting portion from being pushed out by air.
For this reason, a state is ensured in which the ceramic bonding agent is interposed at the interface. Further, since the air vent groove 7 is provided, an appropriate amount of the ceramic bonding agent is held at the interface between the pin fitting hole 4 and the lower half portion 5.

After the fitting and assembling operation is completed, the assembly including the ceramic plate 2, the ceramic pins 3, and the ceramic bonding agent is dried as necessary. The drying temperature is preferably from 80C to 200C, and more preferably from 100C to 130C. If the temperature is too high in order to shorten the drying time, cracks tend to occur at the interface. On the other hand, if the temperature is too low, the drying time may be prolonged or the drying may be insufficient. The drying time is preferably about 1 hour to 6 hours.

The assembly having undergone the heating and drying step is then subjected to main firing under normal pressure. Then, the ceramic plate 2, the ceramic pins 3 and the ceramic bonding agent are sintered together, so that the ceramic plate 2 and the ceramic pins 3 are sintered.
Are joined and integrated. As a result, the desired bonding structure 1
Can be obtained.

Here, when silicon carbide powder is selected as the ceramic powder, the firing temperature at this time is 1700.
It is preferable that the temperature is set to about 2000C to 2000C. If the firing temperature is too low, the sintering of the silicon carbide powder becomes insufficient, so that high bonding strength cannot be obtained. On the other hand, if the firing temperature is too high, the ceramic plate 2 and the ceramic pins 3 themselves may be deformed.

[0030]

Examples 1 to 4 and Comparative Examples Five types of bonding structures 1 and 21 were produced according to the above-mentioned procedure, and the results of strength measurement tests for each were described below.

Embodiment 1 shown in FIG. 1 and FIG.
Only one air vent groove 7 is formed on the outer peripheral surface of the lower half portion 5 of the ceramic pin 3. Details are as already explained.

The specific dimensions of each part in the first embodiment are as follows. The thickness of the ceramic plate 2 (that is, the length of the pin insertion hole 4) is 41 mm, the inner diameter of the large diameter portion 4a of the pin insertion hole 4 is 30 mmφ, and the inner diameter of the small diameter portion 4b is 24 mmφ.
It is. The length of the large diameter portion 4a is 19 mm, and the length of the small diameter portion 4b is 22 mmφ. The total length of the ceramic pin 3 is 43 mm,
The height of the projection 6 is 7 mm. The outer diameter of the ceramic pin 3 is 30 mmφ, and the outer diameter of the projection 6 is 24 mmφ. The length of the air vent groove 7 is 22 mm and the depth is 1.0 mm. In Example 1, β-type silicon carbide powder having an average particle diameter of 0.2 μm was selected as ceramic powder for forming the ceramic plate 2 and the ceramic pins 3. Further, as a ceramic bonding agent, β-type silicon carbide powder 100
A mixture obtained by mixing and kneading 3 parts by weight of an acrylic binder and 30 parts by weight of water with respect to parts by weight was used.

In the embodiment 2 shown in FIG. 2B, the groove 8 is formed not on the outer peripheral surface of the lower half 5 of the ceramic pin 3 but on the inner peripheral surface of the large diameter portion 4a of the pin insertion hole 4. ing. The groove 8 is a bonding agent reservoir groove 8, and the ceramic pin 3
Is perpendicular to the fitting direction of Further, the number of the bonding agent accumulation grooves 8 is three (in the figure, three), and they are formed at equal intervals. The depth of the groove 8 is 0.5 mm or more.
1.0 mm is preferable, and specifically, it is set to 0.75 mm.

In the third embodiment shown in FIG. 3A, a groove 9 is formed on the outer peripheral surface of the lower half 5 of the ceramic pin 3. The groove 9 is a bonding agent reservoir groove 9 and is orthogonal to the fitting direction of the ceramic pin 3. Further, the number of the bonding agent accumulation grooves 9 is three (in the figure, three) and formed at equal intervals. The depth of the bonding agent storing groove 9 is 0.
5 mm to 1.5 mm is preferable, and specifically, it is set to 1.0 mm.

The fourth embodiment shown in FIG. 3B has both the features of the first embodiment and the features of the third embodiment.
That is, on the outer peripheral surface of the lower half portion 5 of the ceramic pin 3, one air vent groove 7 and three bonding agent accumulation grooves 9 are formed, respectively. The air release groove 7 and the bonding agent reservoir groove 9 are in a positional relationship orthogonal to each other.

The above embodiments 2 to 4 are different from the joint structure 1 of the embodiment 1 only in the number of grooves 7, 8 and 9 and the formation positions. It is exactly the same.

The comparative example is a joining structure in the joining structure 21 shown in FIG. Comparative examples are
Embodiment 4 is different from Embodiments 1 to 4 in that no groove is formed in any of the ceramic plate 22 and the ceramic pin 23. Except that the grooves 7, 8, and 9 are not provided, the dimensions and compositions of the respective parts of the comparative example are exactly the same as those of Examples 1 to 4.

The above five types of bonding structures 1, 21
, And a strength measurement test was performed. The principle of the device is as shown in FIG. That is, the joint structures 1 and 21 as the subject are placed upside down on the pair of fixed blocks 11 arranged apart from each other. Joint structure 1,
The pressing head 12 is disposed above the ceramic plate 2 that constitutes 21. This pressing head 12
When the switch is turned on, it moves down at a predetermined speed. Here, the speed was set to 0.5 mm / min.

Then, the ceramic pin 3 was positioned at a position corresponding to the pressing head 12, and the pressing head 12 was moved downward in this state, so that a load was applied to the ceramic pin 3 in a direction opposite to the fitting direction. As a result, the magnitude (kgf / cm ² ) of the pressing force at the time when a crack entered the ceramic bonding agent at the interface of the bonding portion was measured. The fact that this value is large means that cracks are unlikely to occur, and that the strength of the joint is high.

As a result of the above test, it was found that in Example 1, 1500 kgf / cm ² , in Example 2, 1300 kgf / cm ² ,
In Example 3, 1500 kgf / cm ² , and in Example 4, 2000 kgf / cm ²
A value of kgf / cm ² was obtained. On the other hand, in Comparative Example, the value was as low as 900 kgf / cm ² . That is, Examples 1 to 4 were all superior to Comparative Examples. In particular, in Example 4, the value was twice or more the value of the comparative example, and it was clear that the strength of the bonded portion was extremely excellent. Example 1 and Example 3 had the next highest values after Example 4, and in these, almost the same bonding strength was secured.

Now, the characteristic effects of the first to fourth embodiments will be enumerated below. (1) Examples 1 to 4 all have a common feature that grooves 7, 8, and 9 are formed. Therefore, an appropriate amount of the ceramic bonding agent is held at the interface between the ceramic plate 2 and the ceramic pins 3. Therefore, both 2 and 3 can be joined more firmly. Therefore, even if a large load or impact is applied to the joint portion, a problem that a crack is immediately generated at the interface does not occur. Therefore, the problem that the ceramic pin 3 easily comes off from the pin insertion hole 4 is also solved, and the high-strength bonding structure 1 can be realized.

(2) In the second and third embodiments, a plurality of bonding agent reservoir grooves 8 and 9 are formed. For this reason, the amount of the ceramic bonding agent held at the interface increases, the anchor effect also increases, and the ceramic plate 2 and the ceramic pin 3
Can be more firmly joined.

(3) In the first embodiment, the ceramic pins 3
When air is inserted into the pin insertion hole 4, air remaining in the engagement portion is removed due to the presence of the air vent groove 7.
Therefore, the ceramic bonding agent is reliably interposed at the interface, and the ceramic plate 2 and the ceramic pin 3 can be bonded more firmly.

(4) In the fourth embodiment, the effects of (2) and (3) are synergistically achieved, so that the two and three can be more firmly joined to each other. Therefore, it is possible to realize a bonding structure 1 having better strength.

The present invention is directed to each example 1 of the above embodiment.
The number is not limited to 4, and can be changed as follows, for example. The air vent groove 7 does not have to be formed parallel to the fitting direction of the ceramic pin 3 as in the first and fourth embodiments, but may be formed diagonally.

The air vent groove 7 may be formed on the inner peripheral surface side of the pin fitting hole 4 of the ceramic plate 2. ◎ It is preferable that a plurality of (2, 3, 4, 5,...) Air vent grooves 7 are formed instead of only one.
This is because if the number is plural, the amount of the ceramic bonding agent held at the interface is further increased, and moreover, the escape of air becomes more reliable.

In the second, third and fourth embodiments, the number of the bonding agent reservoir grooves 8 and 9 may be reduced to one or two, and conversely increased to four or five. It may be configured.

In each embodiment, it is, of course, permissible to change the cross-sectional shape of the grooves 7, 8, 9 into, for example, a substantially V shape or an R shape. The air vent groove 7 and the bonding agent reservoir groove 9 are preferably formed also on the outer peripheral surface of the projection 6. Further, the bonding agent reservoir groove 8 is preferably formed not only on the inner peripheral surface of the large diameter portion 4a but also on the inner peripheral surface of the small diameter portion 4b.

The first ceramic material does not necessarily have to be plate-shaped, and the second ceramic material does not necessarily have to be pin-shaped. A resin adhesive may be used as the bonding agent.

Here, in addition to the technical ideas described in the claims, the technical ideas grasped by the above-described embodiments are listed below together with their effects. (1) The structure according to claim 3, wherein the number of the air vent grooves is plural. With this configuration, the air is reliably released by the plurality of air vent grooves, so that the strength is further improved.

(2) The structure for joining ceramic materials according to claim 3, wherein the air vent groove is formed to have a length such that one end thereof is partially exposed when completely fitted. With this configuration, since the air is surely evacuated due to the exposure, the bonding agent at the interface of the bonding portion is not extruded, and the strength is further improved.

(3) The ceramic material joining structure according to any one of claims 1 to 3, wherein the recess is a through hole for pin insertion having a step on the inner peripheral surface. (4) The structure for joining ceramic materials according to claim 2 or 3, wherein the groove is formed on a second ceramic material side. With this configuration, the forming operation can be performed more easily than in the case where a groove is formed on the first ceramic material side.

(5) The joining structure of ceramic materials according to any one of claims 1 to 3, wherein the groove is formed after calcination. With this configuration,
Since deformation due to heat at the time of firing is avoided, even a fine groove can be accurately formed.

The technical terms used in the present specification are defined as follows. “Ceramic powder: refers to β-type silicon carbide powder, α-type silicon carbide powder, silicon nitride powder, aluminum nitride powder, boron nitride powder, zirconia powder, alumina powder, mullite powder, and the like.”

[0055]

As described in detail above, according to the first to third aspects of the present invention, it is possible to provide a joining structure of a ceramic material having excellent joining strength.

In particular, according to the second aspect of the present invention, since the amount of the ceramic bonding agent held at the interface is further increased, the two ceramic materials can be bonded more firmly. According to the third aspect of the present invention, since the ceramic bonding agent is degassed at the time of fitting, both ceramic materials can be bonded more firmly.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing a ceramic pin (Example 1) and a ceramic plate of an embodiment.

FIG. 2A is a partial cross-sectional view illustrating a state when the ceramic pins according to the first embodiment are joined, and FIG. 2B is a partial cross-sectional view illustrating a state when the ceramic pins according to the second embodiment are joined.

3A is a partial cross-sectional view illustrating a state when a ceramic pin according to a third embodiment is joined, and FIG. 3B is a partial cross-sectional view illustrating a state when the ceramic pin according to the fourth embodiment is joined.

FIG. 4 is a schematic cross-sectional view for explaining a method of a strength test.

FIG. 5 is a partial cross-sectional view showing a state where a conventional ceramic pin is joined.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Connection structure, 2 ... Ceramic plate as 1st ceramic material, 3 ... Ceramic pin as 2nd ceramic base, 4 ... Pin insertion hole as concave part, 5 ... Lower half of ceramic pin as convex part Parts, 7 ... air vent grooves as grooves, 8, 9 ... bonding agent accumulation grooves as grooves.

Claims (3)

[Claims] A joint formed by fitting a concave portion provided on a first ceramic material and a convex portion provided on a second ceramic material, and connecting the fitted portion via a bonding agent. In the structure, a groove is formed on at least one of the surface of the concave portion and the convex portion of the fitting portion. 2. The ceramic material joining structure according to claim 1, wherein the groove is a joining agent accumulation groove formed so as not to be parallel to a fitting direction of the fitting portion of the ceramic material. 3. The ceramic material joining structure according to claim 1, wherein the groove is an air vent groove continuously provided to a non-fitting portion of the ceramic material.