JPS61215273A - Method of bonding ceramic and metal - 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 an improvement in a method for joining ceramics and metal, and particularly to a joining method in which a thermal stress relaxation body is interposed as an insert material.

[Prior art]

In general, ceramics have excellent wear resistance, heat resistance, corrosion resistance, etc., and are often used in mechanical parts, electronic parts, etc.;
Disadvantages include being difficult to process and being very expensive compared to metal. In order to solve the above-mentioned difficulty in forming and processing, desired parts can be obtained by bonding ceramics to parts obtained by forming and processing metals that are easy to form and process. ing. For this reason, various joining methods have been invented and proposed. Among them, there are pressure welding methods, including diffusion bonding methods, and brazing methods, which are very effective joining methods because they can produce strong joints, but require high temperatures during joining. .

[Problem to be solved]

However, after joining under such high temperatures, when cooled to room temperature, the bonding interface between the ceramic and the metal,
Residual stress occurs due to the difference in thermal expansion coefficients, resulting in destruction of the ceramic or peeling at the bonding interface. A problem arises in that this tendency becomes more pronounced as the joined body becomes larger. In order to solve these problems, the applicant of this invention has filed Japanese Patent Application No. 59-48086, Japanese Patent Application No. 59-112689, and Japanese Patent Application No. 59-214774.
For reference, it indicates that there is an application such as No.

[Means for solving problems]

When joining ceramics and metals, this invention forms a first metal layer of aluminum, aluminum alloy, or aluminum composite on the side that is in contact with the ceramic base material as an insert material, and then heats it to the same degree as the ceramics. A second metal layer having a coefficient of expansion is formed. Further, a third metal layer made of the same metal as the first metal layer and having a coefficient of thermal expansion intermediate between that of the second metal layer and the metal base material is interposed between the second metal layer and the metal base material. Bonding 0 [Function] By interposing the second metal layer having a coefficient of thermal expansion equivalent to that of the ceramic, thermal stress received from the metal base material is blocked and is not transmitted to the ceramic base material.

The first metal layer, which has bonding reactivity to both ceramics and metals, facilitates the bonding between the ceramic base material and the second metal layer. The second metal layer is interposed between the metal base material and the second metal layer to facilitate bonding between the second metal layer and the metal base material. Aluminum as the third metal layer,
When joining with the alloy or its composite interposed, the joining temperature of the first metal layer, that is, the melting point of aluminum, approximately 6
The temperature may be 60°C or lower, and in this case, the ceramic base material, the first metal layer, the second metal layer, the third metal layer, and the metal base material can be joined in one process.However, generally stainless steel is used as the metal base material. Steel materials such as are often used, and the joining temperature often exceeds 660°C. Even in such a case, if the second metal layer and the metal base material are metals of the same type, bonding between them is easy, and the difference in coefficient of thermal expansion between them is generally small. Therefore, it is possible to bond the ceramic base material to the second metal layer and the metal base material through the first metal layer without intervening the third metal layer, but it is difficult to obtain a strong bonded body. It is desirable to interpose a third metal layer,
Delicious. On the other hand, if the second metal layer and the metal base material are different metals, it is generally difficult to bond them together, and it is difficult to bond them unless the third metal layer is interposed therebetween. Furthermore, since the difference in thermal expansion coefficient between the two is generally large, thermal stress remains at the interface after bonding. Therefore, it is necessary to make this third metal layer a metal with a coefficient of thermal expansion intermediate between that of the second metal layer and the metal base material, thereby relieving the thermal stress of the metal base material and ensuring reliable bonding. do. In this case, generally the second metal layer,
The optimum temperature for bonding the third metal layer and the metal base material is approximately 700℃.
A step of bonding at a temperature of 0.degree.

(Example 1) Ceramic base material (silicon carbide; outer diameter 125 m, inner diameter 1
18cm, thickness 10m) 1. First metal layer (pure aluminum A1050; outer diameter 125m+, inner diameter 113cm)
Thickness: 0.6 cod) 2. Second metal layer (iron, nickel, cobalt alloy casting; 3%C11,8~2.8%St, 0.8%
Mn, 30-83%Nls number%C.

;Outer diameter 125m, inner diameter 118mm, thickness 8m) 8,
The third metal layer (same as the first metal) 4 and the metal base material (stainless steel 5uS804L; outer diameter 129cm, inner diameter 103cm, thickness 8m) 5 were ultrasonically cleaned in acetone for 10 minutes, and the first
Laminated as shown in the figure, in a vacuum of about 1O-4 Torr,
Diffusion bonding was carried out at 600° C. for 30 minutes under a pressure of 1 m2/-.

After cooling to room temperature, a good joined body was obtained without any peeling or destruction of the ceramic base material.

(Reference example school) Using the same ceramic and metal base materials as in Example 1, interposing the same first metal layer as in Example 1 and diffusion bonding under the same conditions and cooling to room temperature, the ceramic Significant destruction occurred.

(Example 2) The same second metal and metal base material as in Example 1, and another third metal layer (pure titanium JIS class 2; outer diameter 125 m, inner diameter 118 mm)
, thickness 0.5 mm) in acetone for 10 minutes, and then in a vacuum of about 107 orr under a pressure of 2 ky/mj.
, 880°C XaO diffusion bonding for minutes to form the second metal layer/third
A composite of metal layer/base metal layer was obtained. After cleaning this and the same ceramics and first metal as in Example 1, diffusion bonding was carried out under the same conditions as in Example 1. After cooling to room temperature, no abnormality occurred in the ceramic base material, and a good joined body was obtained.

(Other Examples) As another example, the ceramic base material can be an oxide ceramic such as alumina, zirconia, magnesia, or sialon, or a non-oxide ceramic such as silicon carbide or silicon nitride. The metallic base material can be stainless steel, titanium and titanium alloys, nickel and nickel alloys, and the like.

The first metal layer can be aluminum, an aluminum alloy, an aluminum matrix composite, or an aluminum alloy clad plate.

The second metal layer is made of iron, nickel, cobalt-based alloy casting or its alloy, iron, nickel-based alloy, iron, nickel,
It can be a chromium-based alloy, iron, nickel, or chromium. The third metal layer can be the first metal, or silver, titanium, nickel, zirconium, molybdenum, copper, manganese, chromium, iron, bifoil, a plate, or a thin film formed by a physical or chemical method. . However, the second metal layer is preferably plate-shaped.

Furthermore, the first and third metals may be integrated with the second metal in advance by diffusion bonding or other bonding methods, and may be interposed between the ceramic base material and the metal base material to be diffusion bonded. Further, after the ceramic base material and the first metal layer are bonded, the first metal layer and the composite of the second metal layer/third metal layer/metal base material may be bonded. Such a bonding order is appropriately selected depending on the purpose. Furthermore, the joining method is soldering,
Brazing can be other joining methods such as friction welding.

〔Effect of the invention〕

Top 2 - In bonding mix and metal, it is possible to absorb the residual stress generated due to the difference in thermal expansion coefficients between the two during thermal bonding, thereby preventing destruction of the ceramic or interfacial peeling.

[Brief explanation of drawings]

The drawings show an embodiment of the invention, with FIG. 1 being a side view and FIG. 2 being a top view. In the drawings, 1 is a ceramic base material, 2 is a first metal layer, 3 is a second metal layer, 4 is a third metal layer, and 5 is a metal base material.

Claims (7)

[Claims] (1) In a joining method of joining ceramics and metal with an insert material interposed, the insert material:
The side in contact with the ceramic base material is a first metal layer of aluminum, aluminum alloy or aluminum composite,
Next, a second metal layer having a thermal expansion coefficient comparable to that of the ceramic base material is formed, and a third metal layer is formed on the side in contact with the metal base material. A method for joining the ceramic and metal, which is a thermal stress relaxation body. . (2) The method for joining ceramics and metal according to claim 1, wherein the third metal layer is the same metal as the first metal layer. (3) The method of joining ceramics and metal according to claim 1, wherein the third metal layer is a metal having a coefficient of thermal expansion intermediate between that of the second metal layer and the metal base material. (4) The method for joining ceramics and metal according to any one of claims 1 to 3, wherein the first metal layer is a foil, a thin film, or a plate. (5) The method for joining ceramics and metal according to any one of claims 1 to 3, wherein the second metal layer is a plate. (6) The method of joining ceramics and metal according to any one of claims 1 to 3, wherein the third metal layer is a foil, a thin film, or a plate. (7) The method of joining ceramics and metal according to any one of claims 1 to 6, wherein the joining method is a diffusion joining method.