JPH0632869B2 - Brazing method for ceramics and metal - Google Patents

Description

TECHNICAL FIELD The present invention relates to an improved brazing method using a composite brazing material.

(Prior art and problems) Generally, when brazing ceramics and ceramics,
Utilizing active properties such as Ti, Zr and Hf, a brazing material containing these elements is often used, but a brazing material containing these Ti, Zr and Hf produces a brittle alloy phase, Due to poor workability, it is not possible to obtain dimensions and shapes suitable for brazing.

Therefore, a composite brazing material that does not form a brittle alloy phase, has good workability, and can obtain a size and shape suitable for brazing is widely used.

However, ceramics are widely used in combination with metal, and when joining ceramics and metal, a composite brazing material in which Ti or the like is placed in the middle and a brazing material of the same component is pasted on both surfaces is used. When used, there was a problem that Ti and metal components formed a brittle alloy phase in the vicinity of the brazing interface on the metal side, and a good brazing state could not be obtained.

(Object of the Invention) The present invention has been made to solve the above-mentioned problems, and in brazing ceramics and metal, an intermediate material such as Ti is preferentially diffused to the interface on the side of the ceramics, It is an object of the present invention to provide a brazing method using a composite brazing material in which the reaction at the interface with and is eliminated and only the Ti-free brittle material component controls brazing with the metal.

(Structure of the Invention) The method of brazing ceramics and metal of the present invention is
A composite brazing material in which one of i, Zr, and Hf is used as an intermediate material, and different brazing materials having a melting point difference of 100 ° C. or less are attached to both surfaces thereof. It is characterized in that brazing materials having a high melting point are opposed to each other for brazing.

(Operation) According to such a brazing method, when the brazing temperature is raised, the brazing material having a lower melting point first melts, and at the same time, the intermediate material preferentially melts into the brazing material, and then the melting point When the high brazing material melts, there is no intermediate material that melts into the high melting point brazing material. Therefore, when a brazing material having a low melting point and a brazing material having a high melting point are opposed to each other on the ceramic side and the metal side, respectively, the intermediate material is preferentially gathered at the interface on the ceramic side to obtain strong brazing. At the same time, one of the metals reacts only with the brazing filler metal component having a high melting point, and strong brazing is obtained.

Here, as the brazing material to be bonded to any one of the intermediate materials of Ti, Zr and Hf, a brazing material having excellent wettability with a metal is desirable, and Ag—Cu type and Ag—Cu—Pd type are suitable. Further, it is preferable that the difference in melting point between the brazing materials having different melting points, which are attached to both surfaces of the intermediate material, is within 100 ° C.

Further, since the composite brazing material used in the present invention does not include a brittle alloy layer, it is easy to perform plastic working, and in brazing ceramics and metal, it is preferable that the brazing alloy phase does not form a metal and brittle alloy phase. It is something that can be attached.

(Example) A specific example of the method of brazing ceramics and metal with the composite brazing material of the present invention will be described together with a conventional example.

Example-1 In the composite brazing material 1 shown in the figure, T was used as the intermediate material 2.
i, Ag-Cu28 as the brazing filler metal 3 having a low melting point on the upper surface
%, Ag-Cu 15% as the brazing material 4 having a high melting point on the lower surface.
We made a composite brazing material using and rolled it to 0.07mm.
Finished to a thick plate.

When brazing ceramics and Kovar using this composite brazing material, brazing material of Ag-Cu 28% and ceramics of Ag-Cu 15% and brazing material of Ag-Cu 15% are opposed to Kovar, and brazing is performed in an argon atmosphere. As a result, no brittle alloy phase was formed at the brazing interface with Kovar, and a good brazing state with high joint strength was obtained.

Example-2 In the composite brazing material 1 as shown in the figure, Z was used as the intermediate material 2.
r, Ag-Cu 27% as the brazing filler metal 3 having a low melting point on the upper surface
-In10%, Ag as the brazing material 4 having a high melting point on the lower surface-
A composite brazing material using 28% Cu was prepared and rolled to form a 0.07 mm thick plate material.

When brazing ceramics and Kovar using this composite brazing material, Ag-Cu27% -In10% is made to face ceramics, and Ag-Cu28% is made to face Kovar, and brazing is performed in an argon atmosphere. No brittle alloy phase was formed at the brazing interface with Kovar, and a good brazing state with high joint strength was obtained.

Example-3 As shown in the figure, in the composite brazing material 1, H was used as the intermediate material 2.
f, Ag-Cu28 as the brazing filler metal 3 having a low melting point on the upper surface
%, Ag-Cu31.5% as the brazing material 4 with a high melting point on the lower surface
A composite brazing material using -Pd of 10% was prepared, and this was rolled into a 0.07 mm phase plate material.

Using this composite brazing material, ceramics and Fe-Ni42
% Brazing, Ag-Cu 28% is ceramics, Ag-Cu 31.5% -Pd 10% is Fe-Ni.
As a result of brazing in an argon atmosphere while facing 42%, a brittle alloy phase was not generated at the brazing interface with Fe-Ni 42%, and a good brazing state with high bonding strength was obtained. It was

Conventional Example Using Ti as an intermediate material, a composite brazing material in which Ag-Cu 28% is bonded to both surfaces of the material is made, and then rolled to 0.07.
Finished to a plate thickness of mm.

As a result of brazing ceramics and Kovar in an argon atmosphere using this composite brazing material, a brittle alloy layer composed of Ti, Fe, Co, and Ni was formed at and near the interface between the brazing material and Kovar, and the expected joining strength was obtained. I couldn't get it.

(Effects of the Invention) As described in detail above, the method of brazing ceramics and metal of the present invention provides a composite brazing material having sufficient plastic workability and laminating brazing materials having different melting points on both sides of an intermediate material. When brazing ceramics and metal, the brazing material having a low melting point and the ceramics, and the brazing material having a high melting point and the metal are brazed against each other, so that strong brazing can be obtained and a brittle alloy phase is generated. There is an effect that it can be brazed satisfactorily without.

[Brief description of drawings]

 The figure is a cross-sectional perspective view of the composite brazing material of the present invention.

Claims (1)

[Claims] 1. A composite brazing material in which any one of Ti, Zr, and Hf is used as an intermediate material, and different brazing materials having a melting point difference of 100 ° C. or less are bonded to both surfaces of the compound material. A brazing method for ceramics and a metal, characterized in that a brazing material having a high melting point is faced to the metal or metal side for brazing.