JPS62130843A - Metallic ceramics joining body - 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 <Industrial Application Field> The present invention relates to a joined body of ceramics and metal that is applied to heat-resistant, corrosion-resistant structural parts, etc.

<Conventional technology and its problems> Automotive engine parts, heat resistance and corrosion resistance for chemical plants H
Various ceramics such as M2O3, 5L3N4, and SLC have been developed as A-building materials. These ceramics have high melting points and are in the latter group of heat resistance and corrosion resistance, but when it comes to mechanical strength, they are inferior to ordinary metals and alloys and are often restricted in the field of use. For this reason, it has been proposed to use it as a composite of ceramics and metal bonded together.

It goes without saying that the bonding between ceramic and metal requires high bonding strength, but it is particularly important to eliminate the difference in coefficient of thermal expansion.

A possible solution to this problem is to bond the bonding surfaces via an intermediate layer. Examples of the intermediate layer include ■ soft metal layer (such as aluminum foil), ■ foam metal layer, and ■ composite material layer. The idea is to eliminate expansion strain, and method (2) is a method in which the intermediate layer has a coefficient of thermal expansion intermediate between that of ceramics and metal, and is used as a buffer layer. However, FIG. 2 with a conventional intermediate layer (
A composite with a structure like (a) has insufficient bonding strength and cannot be put to practical use.

<Means to Solve the Problem> In order to solve the problem of thermal expansion strain in the above-mentioned ceramic-metal composite, this invention attempts to analyze the stress of the bonding intermediate layer, and experimentally calculates the strain. It serves a purpose.

The ceramic-metal composite of the present invention has the configuration shown in FIG. Deformable Nj, Tj, N
b, CLLS The objective can be achieved by using a soft metal or alloy such as Mo, Ta, Fa, etc., and using a metal or alloy such as W, which has a thermal expansion coefficient α close to that of the ceramic 1, as the second intermediate figure 4 in contact with the metal 2. This is what I found out.

In the joined body with the configuration shown in Fig. 2 (a), ceramic 1
5L3N4 was used for metal 2, and stainless steel i1Q (S
US 405L), the temperature difference was 975℃ (1000'C→
The maximum tensile stress generated in the intermediate layer when a temperature of 25°C was applied was investigated.

First, when there is no intermediate layer, the maximum tensile stress in 5j3N4 in Figure 2 (b) is measured to be 105 kg in the direction of the arrow in the figure.
This is the value of the load. Next, by inserting an intermediate layer as shown in FIG. 2(a), the e< element of the maximum tensile stress changes somewhat, but there is no large deviation. Although the stress can be reduced by changing the thickness of the intermediate layer, it is practically necessary to make the thickness of this intermediate layer as small as possible.

As a result of various studies, it was found that it was sufficient to apply thermal expansion stress in the radial direction to the interface of the intermediate layer, and the invention of a joined body having the above-mentioned structure was achieved.

Next, the effects will be explained using examples.

<Example> A comparison was made by joining 5L3N4 and stainless steel (SUS 405L) using only Nb 1 mm and Nb-w as an intermediate layer.

5L3N4 with a diameter of 5# and a thickness of 2m was brought into contact with 5L3N4 plates with different Nb/w ratios and a thickness of 1 or 2), and the plates were vacuum sealed in a Pyrex glass container. This bonded pair was bonded using a HIP (hot isostatic press) at 1300° C. for 30 minutes at 100 MPa. Next, a piece of stainless steel (diameter 5#, thickness 21M1) was sealed in contact with W of this joined body, and bonded under the conditions of U < HI Pte 900'C, 100 MPa, 30 minutes S.
A joined body of L3N4/Nb/W/stainless steel was obtained.

As a comparative example, a bonded body of SL3 N4 /W/stainless steel was prepared by sandwiching one layer of W with a thickness of 1fIIIr1.

The maximum tensile stress of the obtained joined body is shown in FIG.

From the figure, it can be seen that the stress is lower when the intermediate layer is a Nb/w2 layer than when the intermediate layer is a single layer, and a minimum stress exists. Next, increase the bonding strength to 0.5 layer M1/m! When a tensile test was performed at n speed, the W single layer was 0.5 to 1 to 34, whereas
In the case of 2 layers b/w, the number was 5 layers g4 or more.

Further, even when the structure near the bonded interface was observed by SEX, no cracks due to thermal strain or the like were found.

[Brief explanation of drawings]

FIG. 1 is a front sectional view of a composite body of the present invention, FIG. 2 is a front sectional view of a conventional composite body, and FIG. 3 is a diagram showing the results of an embodiment of the present invention. 1...Ceramics 2...Metals 3.4...
・Middle class

Claims (1)

[Claims] In a composite body in which a metal and a ceramic are bonded via an intermediate layer, the intermediate layer is composed of two layers, and the intermediate layer in contact with the ceramic is made of Ni, Ti, Nb, Cu, Mo, Ta, Fe.
A metal-ceramic joined body characterized in that the intermediate layer in contact with the metal is a metal or alloy having a coefficient of thermal expansion close to that of the ceramic.