JPH092880A - Joining method of ceramic structure - Google Patents

Abstract

PURPOSE: To provide a method for joining ceramic structures, sufficiently large in the joining strength and not causing the leakage of a gas in the joined structures. CONSTITUTION: A method for joining ceramic structures to each other comprises forming grooves 3a, 3b on the joining surfaces of the ceramic structures 1, 2, respectively, inserting a metal plate 3 larger in thermal expansion coefficient than that of the ceramic into the grooves. Since the ceramic structures 1, 2 are thus joined to each other with the metal plate 3 large in strength, the joint is strong. When the ceramic structures 1, 2 are used in a high temperature state, the metal plate is thermally expanded to closely adhere to the inner walls of the grooves 3a, 3b. Thereby, the sealability of the structures is improved, and the leakage of a gas, etc., in the joined structures can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of joining a ceramic structure which is applied to joining a solid electrolyte type high temperature steam electrolysis cell and a manifold for collecting and distributing gas.

[0002]

2. Description of the Related Art A laminated electrolysis cell 2 as shown in FIG. 2 requires a manifold 1 which distributes water vapor, produced hydrogen and oxygen to each cell 2 and collects from each cell 2.

The laminated electrolysis cell 2 and the manifold 1 are
All of them are usually made of ceramics, and the conventional joining of these ceramic structures is generally performed by an adhesive material.

[0004]

In the conventional joining of ceramic structures, sufficient joining strength is required,
That is, it is difficult to obtain sufficient bonding strength to withstand its own weight and internal pressure, and it is also difficult to prevent hydrogen gas and the like from leaking. The present invention seeks to solve the above problems.

[0005]

According to the method for joining ceramic structures of the present invention, in a ceramic structure used in a high temperature state, grooves are formed on the joining surfaces of one and the other ceramic structure to be joined. , One end of a metal plate having a coefficient of thermal expansion larger than that of ceramics is inserted into the groove of one ceramic structure, and the other end is inserted into the groove of the other ceramic structure to form a joint surface of each ceramic structure. The feature is that they are pressed against each other.

[0006]

In the above description, since the one ceramic structure and the other ceramic structure are bonded by the metal plates having high strength, they are firmly bonded, and the bonded ceramic structures do not drop out due to their own weight.

Further, when the joined ceramic structures are used and the temperature rises to a high operating temperature, the metal plate having a higher coefficient of thermal expansion than the ceramic expands in each groove and adheres to the inner wall of each groove. Since the shrink fit state is achieved, the sealing performance is improved and the internal gas and the like do not leak.

[0008]

EXAMPLE A method of joining ceramic structures according to an example of the present invention will be described with reference to FIGS. 1 (a) and 1 (b).

In the method of joining ceramic structures shown in FIGS. 1 (a) and 1 (b), grooves 3a and 3b are provided on the joining surfaces of the manifold 1 and the laminated electrolysis cell 2, which are ceramic structures, respectively, and the above-mentioned laminated layers are formed. One end of a metal insert 3 having a coefficient of thermal expansion larger than that of ceramics is inserted into the groove 3b provided in the electrolysis cell 2, and the other end of the insert 3 is inserted into the groove 3a provided in the manifold 1. The contact surface between the manifold 1 and the laminated electrolytic cell 2 is brought into pressure contact with each other.

In the above, the laminated electrolytic cell 2 is mainly made of ceramics containing zirconia as a main component and has a coefficient of thermal expansion of about 10 × 10 ^-6 ° C ^-1 . The manifold 1 is also usually made of zirconia. On the other hand, the material of the metal insert 3 is Hastelloy X or the like and has a coefficient of thermal expansion of (16 to 17) ×
At 10 ^-6 ° C ^-1 , a material larger than ceramics is used, and it has a plate shape.

Assembly is completed by pushing the metal insert 3 into the grooves 3a and 3b formed on the joint surface between the laminated electrolysis cell 2 and the manifold 1 so that the metal insert 3 fits into the groove. When it is heated up, it becomes a shrink fit state and the joint surfaces are firmly joined.

The coefficient of thermal expansion of the zirconia forming the laminated electrolysis cell 2 and the manifold 1 and the Hastelloy X forming the metal insert 3 is about 6 × 10 ^-6 ° C. ^-1.
There is a difference.

Therefore, for example, if the length between the grooves of the manifold is 200 mm, the difference between the amount of thermal expansion of the metal insert and the amount of expansion on the groove side when heated to 1000 ° C. is 6 mm.
× 10 ^-6 × 200 × 1000 = 1.2 mm. By setting the gap between the outer dimension of the metal insert and the outer dimension of the groove to 1.2 mm or less during assembly at room temperature, the zirconia and the metal insert come into contact with the inner wall of the groove.

If this gap is set to a smaller value, a stress that causes a permanent strain is applied to the metal insert, so that the contact between the zirconia and the metal insert is maintained in the groove even when the temperature is lowered, and a shrinkage fit state occurs. Bonding without gas leakage is possible.

In this embodiment, if an adhesive material is applied to the joint surfaces of the laminated electrolysis cell 2 and the manifold 1 and the joining method of this embodiment is applied, a more effective seal against gas leakage is possible. Become.

[0016]

According to the method for joining ceramic structures of the present invention, grooves are formed on the joint surfaces of one and the other ceramic structures to be joined, and metal plates having a coefficient of thermal expansion larger than that of ceramics are formed on the respective joint surfaces. By inserting into the groove and joining the respective ceramic structures, since the respective ceramic structures are joined by the metal plate having high strength, the joining is strong and the ceramics are in a high temperature state. When the structure is used, the metal plate thermally expands and comes into close contact with the inner walls of the respective grooves, so that the sealing performance is improved and it is possible to prevent the leakage of gas and the like inside.

[Brief description of drawings]

FIG. 1 is an explanatory view of a joining method according to an embodiment of the present invention,
(A) is a perspective view of the junction part of a laminated electrolysis cell and a manifold, (b) is an enlarged view of the groove in which the metal insert was inserted.

FIG. 2 is an explanatory diagram of a conventional electrolytic cell.

[Explanation of symbols]

 1 Manifold 2 Multilayer Electrolytic Cell 3 Metal Insert 3a, 3b Groove

Claims (1)

[Claims] 1. In a ceramic structure used in a high temperature state, grooves are formed respectively on the joint surfaces of one and the other ceramic structure to be joined, and one end side of a metal plate having a thermal expansion coefficient larger than that of the ceramic is attached. A method for joining ceramic structures, comprising inserting one of the ceramic structures into the groove and inserting the other end into the groove of the other ceramic structure, and pressing the joining surfaces of the respective ceramic structures.