JPH02171203A - Manufacture of ceramic product - Google Patents

Abstract

PURPOSE:To prevent positional deviation of a molded parts, by a method wherein at a stage of the molded parts comprised of a ceramic molding material, protrusion formed on the molded parts is fitted in a through hole and after the molded parts are assembled into a final product form by caulking the tip of the protrusion, the same is burnt. CONSTITUTION:A vessel part 10 constituting five faces of a rectangular parallelepiped excluding the top and a lid part 20 constituting the remaining one face are molded of a ceramic molding material as separate parts from each other. A plurality of protrusions 11 projecting in a pinlike state are formed on the top of the vessel part 10 and a through 21 in which the protrusion 11 is fit is kept formed on a position of the lid parts corresponding to the protrusion 11 when the lid part is put over the vessel part 10. Then when the lid part 20 is put over the vessel part 10 and the through hole 21 is fitted over the protrusion 11, they become a state where the tip of the protrusion 11 is projected a little upward of the through hole 21. Then the protrusion 11 is caulked by pressing a processing horn 30 of an ultrasonic welder against the tip of the protrusion. A molded product whose assembly ad caulking process are completed is burnt by putting into a furnace. With this construction, a matter where joining strength between the molded parts is high and unification of a plurality of constituent parts is high can be manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a ceramic product, and more particularly, to a method of manufacturing a ceramic product constructed by integrally joining a plurality of parts.

[Conventional technology]

Ceramic with excellent heat resistance, wear resistance, corrosion resistance, etc.

These products are used as various structural members, and their applications are also expanding.

The following method is generally used to manufacture such ceramic products.

That is, a ceramic molding material is produced by mixing pre-exploded ceramic powder with an organic binder and other additives, thoroughly kneading the material, molding the ceramic molding material into a predetermined shape, and then firing it. This is a method of manufacturing ceramic products with a desired product shape.

In this method, when producing a ceramic product with a complicated shape or structure, it is necessary to match the shape and structure of the original ceramic molded product to the shape of the final product. However, it is difficult to integrally mold a very complex ceramic molded product due to limitations imposed by the strength of the ceramic molding material and the molding method. Further, it is impossible to integrally mold a hollow molded product.

Therefore, conventionally, i! ! In order to manufacture ceramic products, ceramic products were manufactured by disassembling them into multiple component parts, which were then joined together to obtain the final ceramic product. For joining ceramic parts,
Various joining methods using adhesives, brazing materials, etc. are being considered.

FIG. 3 shows an example of a conventional manufacturing method for a ceramic product consisting of a plurality of component parts as described above. The figure shows a case where a ceramic product having a rectangular parallelepiped outer shape and a hollow interior is manufactured.

In step (a), a molded part made of the ceramic molding material as described above is manufactured. That is, since it is difficult to integrally mold a hollow rectangular parallelepiped that is the shape of the final product, the outer shell of the rectangular parallelepiped is divided into a container portion 1a excluding the lid portion, and a lid portion 1b that closes the upper surface of the container portion 1a. Molding is in progress.

In step (b), each molded part 1a and lb is fired using a normal firing method. Ceramic molding material shrinks when fired, so the fired ceramic part 1a
' and lb' are the original molded parts 1a and tb
It's a little smaller than.

In step (e), the container part la' and the lid part 1b' are assembled into the final product shape with the brazing material 2 interposed therebetween. Note that the fired container part 1a1 and lid part 1b' have dirt, etc. attached to them from the previous processes, and if dirt etc. remain attached, sufficient bonding with the brazing material 2 will not be possible. ,
Clean each part in advance.

In the process (dl), the brazing material 2 is heated and melted, and the container part 1a is
' and the lid part 1b' are integrally joined. Note that the assembled container part 1a' and lid part lb' are surrounded by a positioning jig 3, and the brazing material 2 is heated and bonded with the pressing jig 4 pressed from above the lid part 1b'. By doing so, the parts can be positioned accurately and the adhesion at the joints can be ensured.

[Problem to be solved by the invention]

The conventional manufacturing method as described above has the following problems.

(1) Separately from the firing process of the ceramic product, a heating process is required for bonding with the brazing filler metal 2.

(2) When bonding with the brazing filler metal 2, a positioning jig 3 and a pressure jig 4 are required to prevent the assembled ceramic products from moving or deforming and to obtain sufficient bonding strength. However, it is troublesome to prepare these positioning jigs 3 and the like according to the shape and structure of the ceramic product.

(3) For the positioning jig 3 and pressure jig 4, it is necessary to use a heat-resistant material that can withstand the bonding temperature of the brazing filler metal 2 (usually 700 to 1200°C), such as carbon, graphite, etc. are used, but they are difficult to manufacture and expensive.

(4) Even in cases where multiple component parts can be joined by simply joining parts with a relatively simple structure, it is necessary to heat the entire ceramic product while surrounding it with the above-mentioned positioning jig 3, etc. , manufacturing efficiency is poor and there is a lot of waste in terms of cost.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method that solves the problems of the conventional manufacturing method as described above and can easily manufacture a ceramic product consisting of a plurality of component parts.

[Means to solve the problem]

The method of manufacturing a ceramic product of the present invention which solves the above problems is a method of manufacturing a ceramic product by firing a molded product made of a ceramic molding material in which ceramic powder, an organic binder, etc. are mixed and kneaded. , a method for manufacturing a ceramic product in which a plurality of molded parts made of the ceramic molding material are integrally joined, comprising the following steps (1).
) to (3) are included.

(1) As a plurality of molded parts made of a ceramic molding material, at the joining point of each molded part, one molded part is formed with a protrusion for positioning and caulking, and the other molded part is formed with a protrusion that fits into the protrusion. A process of molding a product with a through hole for positioning.

(2) A process of fitting the protrusions of each molded part into the through-holes, combining the plurality of molded parts, and caulking the tips of the protrusions protruding from the through-holes.

(3) A step of firing the assembled molded parts to obtain a ceramic product.

[For production]

Before firing, the molded parts made of ceramic molding material are assembled into the final product shape by fitting the protrusions formed on the molded parts with the through holes and caulking the tips of the protrusions. By simply firing the assembled molded parts, the desired ceramic product in which each component is integrated can be obtained. In the firing process, the ceramic materials themselves at the joints are integrated with each other due to the firing reaction, so the joint strength and airtightness of the joints are extremely high, and the joints of multiple molded parts are bonded in the caulking process. Since they are integrally joined mechanically, there is no fear that the molded parts will shift during firing. [Example] Next, the present invention will be described in detail below with reference to drawings showing examples.

FIG. 1 shows the process order for manufacturing a ceramic product in the shape of a hollow rectangular parallelepiped similar to the conventional example shown in FIG. 3 described above.

In step fal, similarly to the conventional example described above, the container portion 10 that constitutes five sides of the rectangular parallelepiped except for the top surface, and the lid portion 20 that constitutes the remaining one side are molded as separate parts using a ceramic molding material. Raw materials for ceramic molding materials include various ceramic powders such as alumina and zirconia.
A suitable organic binder and other additives are mixed and kneaded, and it is similar to the ceramic molding material used in ordinary ceramic products. General 92-9
In the case of alumina ceramics with a purity of 9.99, 15 to 25 parts by weight of an organic binder is mixed with 100 parts by weight of alumina.

A plurality of pin-shaped protrusions 11 are formed on the upper surface of the container portion 10. A through hole 21 into which the projection 11 fits is formed in the lid section 20 at a position corresponding to the projection 11 when the lid section 20 is placed over the container section 10. The inner diameter d' of this through hole 21 is formed to a size that allows it to fit snugly into the outer diameter d of the protrusion 11. Further, the height 1 of the protrusion 11 is formed to be slightly larger than the thickness of the through hole 21, that is, the lid part 20. Specifically, the height 1 of the protrusion 11 is
1 is set to be approximately the sum of the thickness of the lid portion 20 and the outer diameter d of the protrusion 11.

In step fbl, the container part IO and the lid part 20 are assembled. When the lid 20 is placed over the container 1O and the through hole 21 is fitted onto the projection 11, the container 1O and the lid 20 are accurately positioned and assembled, and the tip of the projection 11 is positioned above the through hole 21. It will stand out a little.

Step (C1) The processing pawn 30 of the ultrasonic welding device is pressed against the tip of the protrusion 11 to caulk the protrusion 11. The ultrasonic welding device is used for welding and joining various synthetic resins. , and the number + kll is added to the processing horn 30 at the tip.
By transmitting ultrasonic vibrations of about z and heating the joint surface of the member against which the processing horn 30 is pressed by ultrasonic vibrations,
The joining surfaces are fused and joined. In this process, when the processing horn 30 having a hemispherical recess is pressed against the projection 11 made of ceramic molding material, the organic binder contained in the ceramic molding material is melted and softened by ultrasonic vibration, and the processing horn 30 is pressed against the protrusion 11 made of ceramic molding material. The hemispherical caulking part 12 corresponding to the tip shape of the container part 30 is bulged and molded, and the lid part 20 and the container part IO are joined (dl). Put it in a furnace etc. and fire it.

The specific firing method and firing conditions are carried out in the same manner as in the production of ordinary ceramic products, and firing reactions such as degreasing of the organic binder contained in the ceramic molding material and sintering of the ceramic powder proceed. Specifically, for example, in the case of the alumina ceramics, the organic binder is
After heat degreasing in the range of 800"C, 1550~170
Sinter at around 0°C. As a result of this firing reaction, the ceramic materials of the lid part 20 and the container part 1O are fired together at the joint surface where they are in contact with each other, so that the lid part 20
The joint surfaces of 0 and container portion 10 are completely integrated.

The ceramic product C manufactured in this way has component members 10' and 20' corresponding to the respective molded parts 10 and 20 at the caulking part 12, as shown in FIG.
By the mechanical bonding caused by ' and the bonding caused by the firing reaction, they are completely integrated with a sealed space S formed inside. In addition, since the ceramic molding material contracts during the firing process, the ceramic product C after firing is
has shrunk smaller than before firing. therefore,
In order to obtain the ceramic product C with the desired dimensions, it is necessary to set the dimensions of the ceramic molded product 10.20 thick in advance.

In the manufacturing method described above, the shape and structure of the ceramic product C can be any shape and structure other than those shown in the drawings, and the ceramic molding material can be used in accordance with the structure of the ceramic product C to be manufactured. Molding the molded part 10 by dividing it into a plurality of parts that are easy to mold,
It is only necessary to form an appropriate number of protrusions 11 and through holes 21 at the joints between the molded products 10.

It is easier to fire the plurality of molded parts 10 if they are all made of the same ceramic molding material, but the thermal expansion at the beginning of the firing stage and the contraction during the firing process are the same or at approximately the same level. If so, molded parts 10 made of different ceramic molding materials can be used in combination. It should be noted that large differences in thermal expansion coefficients and contraction coefficients are not preferable because internal distortions and cracks will occur due to thermal shrinkage distortion during firing.

After assembling the plurality of molded products 10 and fitting the protrusions 11 and the through holes 21, the tip of the protrusion 11 can be caulked using the above-mentioned ultrasonic welding method, which is a simple and reliable method. However, heating means or molding means other than those described above may be used as long as the predetermined caulked portion 12 can be molded by heating and softening the organic binder of the ceramic molding material. The shape of the protrusion II and the N through hole 21 is not limited to the illustrated embodiment, but can be implemented in any shape by appropriately setting the shape of the machining horn 30, etc.

When assembling a plurality of molded parts 10, if a suitable foil or paste of a brazing material made of a metal material is sandwiched between the bonding surfaces of the molded parts 10, the brazing material will be removed during the firing process. By being heated and melted, the bonding strength or airtightness at the bonding surface can be further enhanced. In this case, unlike conventional manufacturing methods, there is no need to perform a heating and melting process for the brazing filler metal separately from the firing process, so even if the brazing filler metal is used, the number of production steps is not increased. However, when using a brazing filler metal, there are problems with oxidation of the brazing filler metal and heat resistance at firing temperatures, but if the firing step is performed in a vacuum atmosphere, oxidation of the brazing filler metal can be prevented. In addition, 1lJ (with regard to thermal properties, we use a material that becomes liquid crystal at 1550 to 1700°C, which is the firing temperature of ordinary ceramics, and has a coefficient of thermal expansion and contraction similar to that of ceramics such as alumina) as the material for the brazing filler metal. An example of such a material is pure titanium material.

〔Effect of the invention〕

According to the above-described method of manufacturing a ceramic product according to the present invention, at the stage of forming a molded part made of a ceramic molding material, the projections are accurately positioned using the projections and through holes, and the molded parts are caulked together. By firing the assembled molded parts in such an accurately positioned state, in addition to the mechanical joining by caulking, the molded parts can be joined and integrated by the firing reaction. As a result, it is possible to manufacture ceramic products with extremely high bonding strength between molded parts (and extremely high integrity of multiple component parts).

Unlike conventional manufacturing methods, there is no need to perform a joining process using brazing filler metal etc. after the firing of individual molded parts is completed.
Since bonding is performed simultaneously with the firing process, the manufacturing process can be simplified and shortened.

Since the projections and the through holes are accurately positioned and integrated during the firing process, positioning jigs and pressure jigs that are required during the soldering process are no longer required. , the effort and cost of manufacturing these jigs, which are complicated to assemble, can be saved. Furthermore, if a bonding process is performed after the firing process is completed, sufficient bonding strength cannot be obtained unless the bonding surfaces of the fired ceramic parts are cleaned. Since the bonding surfaces are aligned in a step and integrated by firing, the cleaning step as described above is not necessary.

As described above, compared to conventional manufacturing methods, by eliminating the joining process using brazing metal, etc. for ceramic parts after firing, manufacturing equipment and work processes can be simplified and costs can be reduced, and the joining points can be reduced. It will also be possible to improve the quality and performance of ceramic and ceramic products by improving the joint integrity.

[Brief explanation of the drawing]

Claims (1)

[Scope of Claims] 1. A method for manufacturing a ceramic product by firing a molded product made of a ceramic molding material in which ceramic powder, an organic binder, etc. are mixed and kneaded, comprising: a plurality of molded parts made of the ceramic molding material; A method of manufacturing a ceramic product in which are integrally bonded, the method includes the following steps (1) to (
3) A method for manufacturing a ceramic product, comprising: (1) As a plurality of molded parts made of ceramic molding material, at the joining point of each molded part, one molded part is formed with a protrusion for positioning and caulking, and the other molded part is fitted with the protrusion. A process of molding a product with a through hole for positioning. (2) A process of fitting the protrusions of each molded part into the through-holes, combining the plurality of molded parts, and caulking the tips of the protrusions protruding from the through-holes. (3) A step of firing the assembled molded parts to obtain a ceramic product.