JPS59141466A - Ceramic member bonding method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for joining ceramic members, and particularly to a method suitable for joining ceramic members having dense surfaces.

In recent years, silicon nitride, silicon carbide,
So-called new ceramics, such as non-oxide ceramics such as Sialon, aluminum oxide, and zirconium oxide, are rapidly attracting attention, and much research and development is being carried out. These ceramics have many uses as gas turbine rotors, diesel engine cylinders, and other high-temperature machine parts, but all of them have strict requirements for shape and dimensional accuracy, making it difficult to mold and manufacture them as a single piece from the beginning. Often.

For this reason, it is necessary to bond partial products together to create complex shapes, and it is desired to develop a method for firmly bonding ceramics to themselves or ceramics and metals.

Conventionally, a so-called hot press bonding method in which an adhesive is interposed between ceramics and high temperature pressure is applied has been commonly used as a method for bonding ceramics, but it is difficult to bond members with complex irregular shapes.

Multiple types of inorganic adhesives are still being developed,
Various products are manufactured and sold in Japan as well. However, many of these inorganic adhesives are usually made from silica, alumina, or zirconia as their main raw materials, and although they are heat resistant, they have the disadvantage of being weak against forces that would cause the bonded surface to peel off. .

Furthermore, brazing is a bonding method that has higher bonding strength than such inorganic adhesives. By the way, the conditions for brazing ceramics are that the objects to be bonded are wetted by the brazing material and that the objects to be bonded and the brazing material are tightly bonded. At present, sufficient brazing strength cannot always be obtained due to poor brazing properties (so-called wettability) and low reactivity with various substances.

The purpose of the present invention is to solve the problems of the prior art described in 2.7, and to provide a method for joining ceramic members that has extremely high joining strength and has strong resistance to impact loads including thermal stress. It's about doing.

In order to achieve this object, the method for joining ceramic members of the present invention includes a method for joining ceramic members to each other or a ceramic part and a non-ceramic member using a joining material, in which the surfaces to be joined of the ceramic members are joined together. The method involves a step of rapidly heating a part to form a large number of cracks, and then treating the surface to be joined with a liquid that dissolves the ceramic to elute the ceramic along the cracks and increase the roughness of the surface to be joined. The gist of this paper is the characteristic bonding method on the ceramic part side.

That is, in the present invention, by increasing the surface roughness of the ceramic member, a sufficient anchoring effect can be obtained and the bonding strength can be increased, and the layer of the bonding material can effectively act as a stress buffer zone, reducing thermal stress. Resistance to impact loads including Furthermore, dissolving the vicinity of the crack has the effect of rounding off the tip of the crack and preventing the propagation of the crack.

Various types of ceramics can be used as the ceramic member used in the present invention, but the present invention particularly has a dense surface and low reactivity with various substances. It is suitable for joining high-strength ceramic members that cannot be bonded. Examples of such ceramic members include silicon nitride, silicon carbide, sialon, aluminum oxide, and zirconium oxide.

Further, examples of non-ceramic members include various metals and alloy members. Note that in the present invention, it is possible to join ceramic members together, and it is also possible to join a ceramic part side to a non-ceramic member, but when joining ceramic members together, the ceramics may be of the same type, Of course, different types may be used.

Laser light irradiation, infrared heating, sunlight irradiation, etc. are suitable as heating means for partially rapidly heating the surfaces to be joined of such ceramic members, but high energy output can be easily obtained. Laser light irradiation is preferred.

In addition, the liquid used to dissolve the ceramics used to treat the surfaces to be joined where many cracks have formed may be any liquid that can dissolve the ceramics, if necessary, but specifically the following Things can be given. That is, when the ceramic is silicon carbide or silicon nitride, a boiling concentrated caustic soda (NaOH) solution may be used. If the ceramic is zirconium oxide, use hydrogen fluoride, polished ammonium (NH4IF2.) at room temperature, and if the ceramic is aluminum oxide, boiling concentrated phosphoric acid (H3PO4) solution. It will be done. Further, the depth and amount of cracks to be formed on the surfaces to be joined are varied depending on the desired joining strength.

The ceramic member whose surface roughness has been improved in this way is bonded to other members (in case C, a bonding material is used. When bonding ceramic members to each other or a ceramic member and a metal or alloy member) In this case, oxide solder or brazing filler metal can be used as the bonding material.Various kinds of brazing filler metals can be used as the brazing filler metal.
There are various types of wax such as copper solder, silver solder, nickel solder, zirconium solder, titanium solder, gold solder, palladium solder, and brass solder. The brazing method using the Tono brazing method is the same as the normal brazing method.

Examples will be described below, but the present invention is not limited to the following examples unless the gist thereof is exceeded.

Example A commercially available recrystallized alumina plate and a carbon steel plate (co, z%) were joined according to the method of the present invention. That is, as a heating means: 1.
A 2KW laser processing machine was employed, and a multi-mode continuous light was used, the focus of which was adjusted, and the crystalline alumina plate was irradiated with it. The surface was heated from room temperature to 8()0°C in 10 seconds, and then allowed to cool.

Numerous cracks were formed on the surface of the recrystallized alumina plate. After that, the surface where this crack was formed was heated to 60°C in a boiling state.
It was immersed in a phosphoric acid solution of % by weight for 1 hour to elute aluminum oxide along the crack surface. Next, after washing with water and drying, using silver solder, a recrystallized alumina plate and a carbon steel plate (C
O, 2%, ) was bonded.

On the other hand, as a comparative example, a recrystallized alumina plate and a carbon steel plate (C(
1.2%') were joined at 700°C using a pot solder without any treatment on the surface of the recrystallized alumina plate. When the bonding strength of the joined members according to the examples and comparative examples was measured, it was found that those according to the examples were extremely strongly joined, but those according to the comparative examples were extremely weakly joined. There wasn't.

Further, the bonding members according to Examples had little variation in bonding strength and were highly reliable. The cover also had sufficient resistance against impact loads.

When recrystallized alumina plates were tested, the same results as in this example were obtained.

As described above, according to the method of the present invention, ceramic members or ceramic members and non-ceramic members can be firmly joined together, and the joined members are resistant to shock loads including thermal stress. Has resistance.

Agent Tatsuyuki Unuma (2 others)

Claims (1)

[Claims] (11. In a method of bonding ceramic members to each other or a ceramic member and a non-ceramic member using a bonding material, 11) the surfaces of the ceramic members to be joined are partially heated rapidly to form a large number of cracks. A method for joining ceramic members, comprising the step of treating the surface to be joined with a liquid that dissolves the ceramic to elute the ceramic along the cracks and increase the roughness of the surface to be joined. 2) The method for joining ceramic members according to claim 1, wherein the joining material is a brazing material.