JPS6216896A - Brazing filler metal for ceramics - Google Patents

Abstract

PURPOSE:To obtain high brazing strength even without providing a metallized layer to ceramics by joining at least one kind of Ti and Zr at 1-12wt% ratio by the total weight to a brazing filler metal consisting of a specific ratio of Ag-Ni-Cu alloy. CONSTITUTION:At least one kind of Ti and Zr is joined at 1-12wt% ratio by the total weight to one or both surfaces of the brazing filler metal of the alloy consisting of 45-85wt% Ag, 0.3-8wt% Ni and the balance Cu. The reaction phase of the Ti, Zr and the ceramics is formed at the boundary between the brazing filler metal and the ceramics if the ceramics are brazed to each other by using such brazing filler metal, by which the ceramics are eventually joined strongly. The reaction phase of the Ti, Zr and the ceramics is formed at the boundary between the brazing filler metal and the ceramics and the Ag-Cu-Ni phase rich with Cu and Ni is formed at the boundary between the brazing filler metal and metal if the metal and ceramics are brazed by directing the brazing filler metal joined with the Ti and Zr on one surface toward the ceramic side.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a brazing material used for brazing ceramics and ceramics and ceramics and metals.

(Prior Art) Conventionally, methods for joining ceramics and metals include a high melting point metal method, an oxide solder method, an active metal method, and the like.

The high melting point metal is one in which a metallized layer is provided by coating Mo-Mn on ceramics and firing, followed by Ni plating, and bonding is mainly performed using an Ag-Cu eutectic solder.

The oxidation holder method is a method in which various mixtures of oxides are used as insert materials, and bonding is generally performed by heat treatment in air at low temperatures and in an inert or reducing atmosphere or vacuum at high temperatures.

The active metal method uses a high melting point metal (T 1
This is a method of bonding using a reaction at the interface between the ceramic and the ceramic.

(Problems to be Solved by the Invention) By the way, the above-mentioned methods for joining ceramics and metals have their own advantages and disadvantages, and there is a problem that sufficient strength cannot be obtained with sufficient brazing. A brazing filler metal having a composition such as CuTi34wt% (melting point 880℃) or Ti-Ni24.5wt% (955℃)
is used. However, these have the disadvantage that they must be brazed at high temperatures, and joining at high temperatures generates large thermal stresses. Also, Ag has a slightly low melting point.
There is a brazing filler metal made of 28ht% Cu clad with Ti, but this brazing filler metal has poor brazing strength and requires a weight of 10 to 12 kg/
It will only be about N2.

Therefore, the present invention aims to provide a brazing material for ceramics that can obtain high brazing strength without providing a metallized layer on ceramics by applying the active metal brazing method.

(Means for Solving the Problems) The brazing filler metal for ceramics of the present invention for solving the above problems contains 45 to 85% Ag and 0.3 to 8% Ni.
t%, and at least one of Ti and Zr is added to one or both sides of the brazing filler metal, the balance being Cu, in an amount of 1 to 12% based on the total amount.
It is formed by bonding at a ratio of wt%.

In the brazing material for ceramics of the present invention, Ag-N 1
-The reason for setting Ag in the Cu alloy to 45 to 85 wt% is that A
With g45wt% ungrooved, the difference between the solidus temperature and liquidus temperature of the brazing filler metal is 100°C or more, which is undesirable because the melt sometimes separates during brazing, and the temperature during brazing is also high. , Brazing sometimes has the problem of generating large thermal stress, and when the brazing temperature exceeds 85-t%, the difference between the solidus temperature and liquidus temperature of the brazing material becomes 100°C or more, resulting in the same problem as above. This is because problems will arise. N i 0.3~8
The reason why it is set as wt% is that brazing increases the strength and prevents corrosion of the joint.If it is less than 0.3wt%, the strength of brazing will not increase, and if it exceeds 8wt%, the Ag-Ni-Cu alloy When making Ni, Ni segregates and does not dissolve in solid solution, so 0.
The content is 3 to 8 wt%. Cu is necessary to lower the melting point by alloying with Ag, improve wettability to iron-based base materials, and improve wettability to some extent to ceramics.

However, Ti −,
1 to 12 wt% of at least one type of Zr based on the total amount
The reason for bonding at a ratio of
If it exceeds 2-t%, a metallized layer will be formed on the ceramics, so the content is set at 1-12-t%.

(Function) When ceramics are brazed together using a brazing filler metal for ceramics according to the present invention having the above configuration, for example, a brazing filler metal with Ti and Zr bonded to both sides, a reaction between Ti, Zr and the ceramics occurs at the interface between the brazing filler metal and the ceramics. phases are formed,
It will be firmly joined. Also, T I % on the - side
When the metal and ceramic are brazed with the Z r bonded brazing filler metal facing toward the ceramic side, a reactive phase of T I % Z r and the ceramic is formed at the interface between the brazing filler metal and the ceramic, resulting in a strong bond. Therefore, the interface between the brazing filler metal and the metal contains Cu%Ni-rich Ag-Cu.
-Ni phase is formed, and the addition of Ni results in an even stronger bond.

(Example) Specific examples of the brazing filler metal for ceramics according to the present invention will be described in comparison with conventional examples.

The brazing fillers for ceramics of Examples 1 to 7 and the brazing fillers for ceramics of Conventional Examples 1 to 3 having the component compositions shown in the left column of the table below were processed and formed into a thickness of 0.1 mm, a width of 31 m, and a length of 101 m. , brazing thickness 5mm, width 10mm, length 50cm-
One end of the ceramic or alloy joint pieces were overlapped to a length of 3 mm, and the brazing filler metals for ceramics of Examples 1 to 7 and Conventional Examples 1 to 3 were interposed between the two pieces in an Ar gas atmosphere. When a ceramic or metal joint piece was heated in a heating furnace and subjected to a shear test by pulling it in the longitudinal direction, the results shown in the right column of the table below were obtained.

(Leaving space below) As is clear from the results in the right column above, the brazing of ceramics with each other and the brazing of ceramics with metal using the brazing fillers for ceramics of Conventional Examples 1 to 3 is higher than that of Examples 1 to 7, compared to the shear strength of the parts. It can be seen that the shear strength of the parts is high when brazing ceramics together or between ceramics and metal using a brazing filler metal for ceramics.

In addition, in the brazing of Examples 1 to 7, when the cross section of the joint piece was observed, Ti was added to the interface between the brazing material and the ceramic.
It was observed that a reaction phase of Zr and ceramics was formed, resulting in a strong bond. In addition, the middle part of the brazing layer was an Ag-Cu-Ni phase containing a large amount of Ag, and it was found that this acted as a cushion for stress relaxation. Furthermore, it was observed that a Cu--Ni-rich Ag--Cu--Ni phase was formed at the interface between the brazing filler metal and the metal, and that the addition of Ni resulted in a strong bond.

(Effects of the Invention) As explained above, according to the brazing filler metal for ceramics of the present invention, brazing between ceramics and ceramics and metals can be achieved without providing a metallized layer on the ceramics, and with Ti at the interface of the ceramics. , it has the effect of forming a reactive phase between Zr and ceramics and also forming a Cu-Ni-rich Ag-Cu-Ni phase at the metal interface, resulting in a strong bond, and is different from conventional brazing filler metals for ceramics. It can be said to be an epoch-making product that can be replaced.

Claims (1)

[Claims] Ag45-85wt%, Ni0.3-8wt%, balance C
1. A brazing filler metal for ceramics, characterized in that at least one of Ti and Zr is bonded to one or both sides of an alloy brazing filler metal made of u in a proportion of 1 to 12 wt% based on the total amount.