JPH09132473A - Brazing filler metal for ceramics - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brazing filler metal fit to carry out satisfactory joining of ceramics not accompanied by cracking without metallizing the ceramics by specifying a compsn. consisting of at least Cu, Ag, Ti and Zr. SOLUTION: This brazing filler metal consists of 2-10wt.% Ti, 1-8wt.% Zr and the balance Cu and Ag. It is fit to join ceramics to ceramics, a metal, etc., at 950 deg.C brazing temp. in vacuum.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brazing material for ceramics suitable for joining ceramics to ceramics, ceramics to metal and the like.

[0002]

2. Description of the Related Art In recent years, ceramics technology has made great progress, and various products using ceramics materials have come to the forefront. However, if a product is completed with ceramics alone, there is no problem at all, but it has become more common to braze the same ceramics to ceramics to complete the product, or braze metal to ceramics to complete the product. . However, the coefficient of thermal expansion of ceramics is smaller than that of metal, and cracks often occur in ceramics due to the thermal stress generated due to the difference in expansion coefficient when brazing with metal.

Conventionally, a refractory metal method, an active metal method, an oxide solder method, or the like has been used as a method for joining the above-described materials, one of which is made of ceramics. Among them, the refractory metal method is a method in which a metal film of Mo—Mn is applied on ceramics and baked, that is, the surface of the ceramics is metallized in advance to form a metal film.
After that, it is a method of joining using Ag—Cu eutectic brazing. The oxide solder method is a method in which various oxide mixtures are sandwiched between materials to be bonded as an insert agent, and heat treatment is performed in an inert gas atmosphere, a reducing gas atmosphere, a vacuum, or the like to perform bonding.

The active metal method is active with respect to oxygen (T
(i, Zr, etc.) are joined by utilizing the reaction of refractory metal and ceramics. The conventional joining method using the active metal method will be described with reference to Table 1. As a sample, a ceramic plate having a length of 15 mm × width of 15 mm × thickness of 0.
55 mm Al 2 O 3 (hereinafter referred to as sample 1) was used, and SUS304 (hereinafter referred to as sample 2) having a length of 15 mm × width of 15 mm × thickness of 0.5 mm was used as a metal plate.

[0005]

[Table 1]

(Conventional Example 1) As shown in Conventional Example 1, Ag
When a brazing material of 70, Cu28, and Ti2 (unit: wt%) was sandwiched between Sample 1 and Sample 2 and joined at a temperature of 950 ° C. in vacuum, the ceramics cracked and became unusable.

(Conventional Example 2) As shown in Conventional Example 2, Ag
70, Cu25, Ti3, In2 (unit wt%) brazing filler metal is sandwiched between sample 1 and sample 2, and similarly in vacuum at 950 ° C.
When joined at the temperature of 1, the ceramics cracked and became unusable.

[0008]

The refractory metal method has a drawback that the process is complicated and the cost is high because there is a metallizing step before joining. The oxide solder method has a low melting point and a high melting point, but the low melting point lowers the heat resistant temperature of the joint at a working temperature of 300 to 400 ° C, and conversely the high melting point is 1200 to 2000 ° C. There is a drawback that the working temperature becomes too high and the energy cost rises.

Further, the active metal method is Ag-Cu-Ti, A
There are brazing materials such as g-Cu and they are widely used. According to this method, metal-ceramics or ceramics-ceramics can be directly joined without metalizing, but thermal stress is generated due to the difference in thermal expansion coefficient. Therefore, as shown in Table 1, when joining dissimilar materials including a thin non-bonding material, the thickness is particularly 1 m.
With ceramics of m or less, cracks were generated and it was difficult to bond them.

The present invention has been made in view of the above circumstances, and an object of the present invention is to apply the above-mentioned active metal method to the ceramic material without metalizing and without causing cracking of the ceramic material, one of which is a ceramic material. The present invention provides a brazing material for ceramics, which is composed of

[0011]

In order to solve the above problems, the gist of the present invention is at least Cu, Ag, Ti, Z.
It is a brazing material for ceramics consisting of four components of r, Ti
It is characterized by containing 2 to 10 wt% and Zr 1 to 8 wt%.

[0012]

Embodiments of the present invention will be described below. The brazing material for ceramics according to the present invention is C
It is composed of four components of u, Ag, Ti, and Zr, of which Ti is 2 to 10 wt% and Zr is 1 to 8 wt%.
And Cu and Ag are contained as the remaining components.

The reason for setting Ti2 to 10 wt% is 2 wt
% Or less, the brazing filler metal does not react with the ceramics 10
This is because Ti that has not reacted with the ceramics produces a hard and brittle alloy at a content of more than wt% and causes a decrease in the bonding strength.

On the other hand, the reason why Zr is set to Zr1 to 8 wt% is that if the content is 1 wt% or less, the wetting of the brazing material to the ceramics will be poor. This leads to a decrease in bonding strength.

(Embodiment) An embodiment of the present invention will be described below using Table 2 in order to prove the reason for the above numerical values. As the sample, the same samples as those in the conventional example were used for sample 1 and sample 2, and as sample 3, the length of the ceramic plate was 15 mm × width 15
ZrO2 (hereinafter referred to as sample 3) having a size of 0.5 mm and a thickness of 0.55 mm was used.

[0016]

[Table 2]

(Example 1) As shown in Example 1 of Table 2, Ag70, Cu25, Ti2, Zr1 (unit: wt)
%) Brazing filler metal between sample 1 and sample 2
When bonded at a temperature of 0 ° C., no cracks were found in the ceramics and it was usable.

Example 2 As shown in Example 2 of Table 2, Ag36, Cu53, Ti6, Zr5 (unit: wt)
%) Brazing filler metal between sample 1 and sample 2
When bonded at a temperature of 0 ° C., no cracks were found in the ceramics and it was usable.

(Example 3) As shown in Example 3 of Table 2, Ag49, Cu35, Ti9, Zr7 (unit: wt)
%) Brazing filler metal between sample 1 and sample 2
When bonded at a temperature of 0 ° C., no cracks were found in the ceramics and it was usable.

Example 4 As shown in Example 4 of Table 2, Ag47, Cu35, Ti10, Zr8 (unit: wt)
%) Brazing filler metal between sample 1 and sample 2
When bonded at a temperature of 0 ° C., no cracks were found in the ceramics and it was usable.

Example 5 As shown in Example 5 of Table 2, Ag41, Cu54, Ti3, Zr2 (unit: wt)
%) Brazing filler metal between sample 2 and sample 3
When bonded at a temperature of 0 ° C., no cracks were found in the ceramics and it was usable.

Example 6 As shown in Example 6 of Table 2, Ag47, Cu35, Ti10, Zr8 (unit: wt)
%) Brazing filler metal between sample 2 and sample 3
When bonded at a temperature of 0 ° C., no cracks were found in the ceramics and it was usable.

Reference Example 1 As shown in Reference Example 1 of Table 2, Ag47, Cu35, Ti12, Zr10 (unit w
t%) brazing filler metal is sandwiched between sample 1 and sample 2,
When bonded at a temperature of 50 ° C, cracks occur in the ceramics and the bonding strength is 0.05 kg due to the destruction of the bonding interface.
/ Mm2 was weak and could not be used.

[0024]

As described above, the brazing material for ceramics of the present invention does not require a metalizing step and can perform good joining without cracking of the ceramics.

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Claims (1)

[Claims] 1. At least 4 of Cu, Ag, Ti and Zr
A brazing filler metal composed of components, of which Ti is 2 to 10
wt%, containing 1-8 wt% Zr, the balance Cu and Ag
A brazing material for ceramics, which is characterized by being composed of