JPS62137170A - Brazing method - Google Patents

Abstract

PURPOSE:To obtain a sufficient joining strength without a restriction of a kind of a brazing filler metal, by forming an active metal, and a metallic protective layer which does not form an active metal and an intermetallic compound, from a ceramic side, and executing the brazing. CONSTITUTION:On the surface of ceramics 1, an active metal 2 is formed, and on said metal, a metallic protective layer 3 which does not form an active metal and an intermetallic compound and consists of a combination of one kind or two kinds or more of silver, copper, and chrome is provided, and it is brazed to a metallic material 5 by a brazing filler metal 4. In this case, the active metal 2 and the brazing filler metal 4 are separated by the metallic protective layer 3, and no intermetallic compound is formed. Accordingly, even if a brazing filler metal for forming an active metal and an intermetallic compound is used, no intermetallic compound is formed, being different from a conventional metallization, therefore, a sufficient joining strength for a practical use is obtained. Also, since a brazing filler metal which is composed mainly of gold can be used, the corrosion resistance of the joined part also becomed extremely better than that of a joined part which has used silver brazing filler metal, and it can be applied to that which requires a corrosion resistance in the joined part, as well.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a structure of a metallized portion on a ceramic surface in a method for joining ceramic materials.

[Summary of the invention]

In ceramic-ceramic and ceramic-metal bonding, the structure of the metallized part on the ceramic surface is made from the ceramic side with an active metal and a metal protective layer that does not form intermetallic compounds with the active metal, achieving sufficient bonding strength without the constraints of the bonding filler metal. I made it possible to obtain.

[Conventional technology]

Conventionally, when using active metals to metalize and bond ceramic surfaces, it is important to avoid forming intermetallic compounds with the active metals.
Silver solder was used.

[The shortcomings that the invention attempts to solve]

Conventionally, when a ceramic surface is metallized using an active metal and then brazed directly, the problem has been that the strength of the joint is insufficient if a brazing material that forms an intermetallic compound with the active metal is used. Therefore, the object of the present invention is to solve these conventional drawbacks and to obtain sufficient strength without forming an intermetallic compound with the active metal even if a brazing material other than wax is used.

[Means for solving problems]

In order to solve the above problem, the present invention arranges a metal protective layer that does not form an intermetallic compound with the active metal on the surface of the active metal, thereby preventing a decrease in bonding strength without saving brazing material.

[Effect]

When metallized ceramics having the above configuration are bonded using a brazing material, the ceramic and the metallized part are bonded by the active metal, and the active metal and the metal protective layer that does not form an intermetallic compound are bonded by diffusion, and the active metal and the metal are bonded by diffusion. A metal protective layer that does not form an intermediate compound blocks contact between the brazing material and the active metal, and is bonded to the brazing material by liquid phase diffusion, thereby providing strong bonding strength.

〔Example〕

Embodiments of the present invention will be described below based on the drawings. 1st
In the figure, an active metal 2 is placed on the surface of a ceramic 1.
A metal protective layer 3 that does not form an intermetallic compound with an active metal is provided thereon by means such as PVD or CVD, and is brazed with a metal material 5 using a brazing material 4 . With such a configuration, the active metal 2 and the brazing material 4 are
It is isolated by the metal protection N3 and cannot form intermetallic compounds. Therefore, even if a brazing material that forms an intermetallic compound with an active metal (for example, a brazing material mainly composed of gold) is used,
Unlike the conventional metallization shown in FIG. 2, since no intermetallic compound is formed, a bonding strength suitable for practical use can be obtained.

Table 2 shows the bonding strength when the metallization of the present invention and the conventional metallization were bonded using a brazing material containing gold as a main component.

It is clearly seen that the bonding strength is improved by this invention. Furthermore, since it is possible to use a brazing material mainly made of gold, the corrosion resistance of the joint is much better than that of conventional joints using silver brazing material, making it suitable for use in items that require corrosion resistance in joints such as watch cases. Can be applied.

〔Effect of the invention〕

As explained above, in metallizing a ceramic surface, this invention provides a metal protective layer on the surface of an active metal, thereby making it possible to bond without forming an intermetallic compound even if any brazing material is used. This has the effect of preventing a decrease in bonding strength. Furthermore, since it is possible to use a brazing material mainly composed of gold, there is an effect that the corrosion resistance of the joint portion is also improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the structure of a metal layer according to the present invention, and FIG. 2 is a sectional view showing the structure of a conventional metallized portion. ■... Ceramics 2... Active metal 3... Metal layer: 1Jffl 4... Brazing material 5... Metal material or more

Claims (1)

[Claims] In products where the ceramic surface is metallized and bonded to other ceramics or metals by brazing or the like, the metallized part is made of an active metal from the ceramic side, one type of silver, copper, chromium that does not form an intermetallic compound with the active metal, or , a method of forming a metal layer consisting of a combination of two or more types and brazing the ceramic.