JPH059084A - Method for joining ceramics - Google Patents

Abstract

(57) [Abstract] [Purpose] To facilitate the method of joining ceramics to ceramics or metal, especially to metallize the surface of ceramics. [Structure] After adding 2 to 20% by weight of Ni powder in a metallized layer mainly composed of Mo powder or W powder and heating and firing at 1300 ° C. to 1375 ° C. in a reducing atmosphere to perform metallization Braze. [Effect] Compared with the conventional method, since the metallized layer does not contain glass, the quality control and process control associated therewith can be omitted, and the economical effect is large.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for joining ceramics and ceramics, or ceramics and metal.

[0002]

2. Description of the Related Art For joining ceramics, particularly alumina ceramics, to Kovar, Ni-Fe alloy, iron, copper, stainless steel, etc., a method is known in which the surface of the ceramic is once metalized and then brazed to the other metal. ing. Figure 2
Shows the composition of the conventional metallization layer of ceramics disclosed in Japanese Patent Laid-Open No. 2-124787, in which 1 is a ceramic, 2 is a metallization layer, and 2c is a tungsten-glass first layer. The metallization layer, 2d, is a second metallization layer made of nickel.

Next, the metallization process will be described. A mixed powder of tungsten powder and glass powder is applied to the surface of the ceramic 1 and then dried to form a first layer 2c. Next, a powder of any one of nickel, nickel oxide, and nickel salt, or a combination of two or more thereof, is applied onto the first layer and then dried to form the second layer 2d. After that, in the temperature range of 1200 to 1400 ° C., and 1 <H ₂
/ H ₂ O <100,000 is fired in a mixed atmosphere.

[0004]

Glass powder is used in the composition forming the first layer of the metallized layer. The glass powder is used depending on its melting point, particle size and weight ratio to the tungsten powder. The characteristics of the chemical conversion layer itself change greatly. The firing temperature and firing atmosphere are also limited depending on the composition of the glass. For this reason, there has been a problem that a great deal of cost is required for quality control and manufacturing process control required by using glass.

The present invention has been made to solve the above problems, and an object thereof is to provide a method for metallizing ceramics which does not use glass powder in the metallizing composition.

[0006]

The method for joining ceramics according to the present invention is characterized in that a metallized composition mainly containing molybdenum powder or tungsten powder is used as a first layer, and then the metallized composition is limited to this metallized composition. A metallized composition to which a specified amount of nickel powder has been added is used as a second layer, and this is fired to metallize the ceramics, and then brazed using a brazing material such as an Ag-Cu eutectic braze. Is.

[0007]

The first metallization layer according to the present invention provides a strong bond with the ceramics, the second metallization layer bonds well with the first metallization layer, and at the same time improves the wettability by the brazing material.

[0008]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a 10 × 10 × 30 mm alumina ceramic containing 92% by weight of Al ₂ O ₃ . 80% by weight of Mo powder and 20 on the surface of this square
Approximately 30 μ of the first metallization layer 2a composed of Mn powder of weight%
It was applied by printing at a thickness of m. Furthermore, 3.5 wt% Ni powder, 77.2 wt% Mo powder and 19.3 wt%
The second metallization layer 2b made of Mn powder of No. 2 was printed and applied in a thickness of about 1.5 μm. N ₂ -H ₂ dew point it is about 30 ° C.
Firing was performed at 1325 ° C. for 30 minutes in a mixed gas atmosphere. An Ag—Cu eutectic braze was placed on the metallized surface treated in this way, and heated at 800 ° C. for 15 minutes in H ₂ gas to melt the brazing filler metal. After cooling to room temperature, the sample was cut to observe the extent of braze flow and the contact angle between the metallized surface and the braze was measured to be 35 °.

On the other hand, an Ag-Cu eutectic brazing material is sandwiched between two metallized ceramic test pieces as described above, and H
Brazing was performed by heating at 800 ° C. for 15 minutes in ₂ gases. When the mechanical bonding strength of this bonded body was measured by three-point bending, it was 16.5 kg / mm ² . When the joint of the test piece after the strength test was cut and the cross section of the joint was observed with a scanning electron microscope, it was confirmed that the Ag-Cu eutectic braze was well flowing on the good metallization layer. It was

Embodiment 2. On top of the first metallization layer of Example 1, 20 wt% Ni, 64 wt% Mo and 16 wt%
The second metallization layer made of Mn was printed and applied in a thickness of about 15 μm, and this was fired at 1300 ° C. for 30 minutes in a N ₂ —H ₂ mixed gas atmosphere with a dew point of 30 ° C. to metallize the ceramics. .. Using this metallized ceramic, the contact angle showing the flow degree of the brazing material on the metallized surface and the mechanical bonding strength were measured in the same manner as in Example 1, and the contact angle was 0 °. The strength was 20.4 kg / mm ² . Further, when the cross section of the joint portion was observed in the same manner as in Example 1, it was found that the metal crystals in the portion of the second metallization layer were coarsened, and that the second metallization layer contained more Ni. Turned out to be unfavorable.

Embodiment 3. The composition of the second metallization layer is 2
Wt% Ni, 78.4 wt% Mo and 19.6 wt%
When the same treatment as in Example 1 was performed using Mn of, the contact angle was 127 ° and the bonding strength was 17.5 kg / mm ² .

Embodiment 4. The composition of the first metallization layer is 9
A composition consisting of 0 wt% W powder and 10 wt% Fe powder was used, with 5 wt% Ni and 8 as the second metallization layer.
A composition consisting of 5.5 wt% W and 9.5 wt% Fe was used in an N ₂ —H ₂ gas atmosphere with a dew point of about 30 ° C.
In the case where metallization baking was performed at 375 ° C. for 30 minutes, the contact angle was 33 ° and the bonding strength was 17.3 kg / mm ² .

As a comparative example, the strength of the jointed parts was measured by a method which is a standard specification of metallization. 80% by weight of Mo-20 on the surface of the alumina ceramics of Example 1.
It applied by printing wt% of Mn, dew point of about 30 ℃ N ₂ -H ₂
The mixture is baked in a mixed gas atmosphere at 1450 ° C. for 30 minutes, Ni is plated on the surface, and 900 ° C. in H ₂ gas at 30 ° C.
After sintering for a minute, they were brazed with Ag-Cu eutectic brazing. The bonding strength was 17.2 kg / mm ² .

[0014]

As described above, according to the present invention, since the metallized composition does not contain glass, the quality control and manufacturing process control associated therewith are simplified, and the same level as in the prior art is obtained. There is an effect that the bonding strength can be obtained.

[Brief description of drawings]

1 is a cross-sectional view showing the composition of a metallization layer according to Example 1 of the present invention.

FIG. 2 is a cross-sectional view showing the composition of a conventional metallization layer.

[Explanation of symbols]

 1 Ceramics 2 Metallized Layer 2a Mo-Mn Layer 2b Mo-Mn-Ni Layer 2c W-Glass Layer 2d Ni Layer

Front page continuation (72) Inventor Kazuo Kawahara 8-1-1 Tsukaguchihonmachi, Amagasaki City Mitsubishi Electric Corporation Materials Research Laboratory (72) Inventor Kimoto Moriwaki 8-1-1 Tsukaguchihonmachi, Amagasaki Materials Mitsubishi Electric Corporation In the laboratory

Claims (1)

Claim: What is claimed is: 1. A first metallization composition comprising molybdenum powder or tungsten powder as a main component is applied to a ceramic surface, and 2 to 20% by weight of nickel powder is added to the metallization composition. The method for joining ceramics, comprising applying the second metallized composition described above, heating at 1300 to 1375 ° C. in a reducing atmosphere to metallize the surfaces of the ceramics, and then performing a brazing operation to perform the joining.