JPS62289396A - Joining method for ceramics - Google Patents

Abstract

PURPOSE:To improve the reliability of the joint between ceramics and material to be welded and to improve the corrosion resistance of the joint part by using a 4-component brazing filler metal consisting of Ag, Cu, Sn, and Ti. CONSTITUTION:The ceramics and ceramics or the ceramics and metal are joined in an inert atmosphere or reducing atmosphere by using the brazing filler metal consisting of the four components; Ag, Cu, Sn, and Ti. The compsn. ratios of the brazing filler metal by weight are preferably 10-40% Ag, 8-56% Cu, 8-56% Sn, and 5-25% Ti; furthermore, the Cu and Sn are preferably 20-80% Cu and 80-20% Sn. The bonding of non-oxide ceramics such as SiN is made possible by using such brazing filler metal. The joining with the high reliability and corrosion resistance is executed with decreased variance.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a low-temperature bonding method for ceramics, and in particular,
The present invention relates to a method for joining ceramics or ceramics and metals in an inert atmosphere or a reducing atmosphere.

[Conventional technology]

BACKGROUND ART Conventionally, when bonding ceramics together or metals and ceramics, the Telefunken method, the active metal method, the copper compound method, and the like have been used as joining methods.

However, the Telefunken method and the copper compound method require multiple bonding steps, and
When joining, it is necessary to heat it to over 1000℃,
The drawback was that it could not be bonded at low temperatures. on the other hand,
According to the above active metal method, it is possible to join in only one process, but when ceramics such as A203, ZrO2, or SiC and metals such as SS or SUS are joined in one operation. The higher the bonding temperature, the more ceramics are used. There is a drawback that the stress generated due to the difference in thermal expansion between the bonding material and the material to be bonded cannot be alleviated, and reliable bonding may not be possible.

Therefore, in order to buffer the stress generated due to the difference in thermal expansion during such joining, a buffer material may be inserted between the joining material and the materials to be joined. In order to join the bonding material made of ceramics, the buffer material, and the material to be bonded in step -, the bonding temperature between the bonding material made of ceramics and the buffer material, and the bonding temperature between the buffer material and the material to be bonded must be adjusted. It is necessary to keep them the same, and when using a commercially available silver solder brazing material as a buffer material, it is not preferable to solder at high temperatures, and it is preferable to join at 850 ° C or less.
On the other hand, brazing materials commonly used in the active metal method include ^g-Cu-Ti, Ag-Ni-Ti, etc., and N1cholas (USP No. 4,4
71,028) also developed a Cu-5n-Ti brazing material.

However, the general joining temperature of these three-component brazing materials is 850°C to 1050°C, which is high and cannot sufficiently buffer the stress when joining the materials to be joined, causing cracks in the ceramics. There were disadvantages such as peeling after bonding. Furthermore, conventional bonding methods lack tactility and are inferior in reliability.

Therefore, a technical object of the present invention is to provide a method for joining ceramics that is capable of joining ceramics and materials to be joined in a simple process at low temperatures, and is highly reliable and highly corrosion resistant.

[Technical means and effects of the present invention]

In order to achieve this object, the present invention uses silver (A
s), copper (Cu), tin (Sn), and titanium (T
It is configured to join ceramics and materials to be joined using a brazing material consisting of the four components i).

That is, the tin (Sn) contributes to improving the wettability of the ceramic bonding layer and is effective in lowering the melting point of the brazing material.
Furthermore, when used in combination with a brazing material such as silver solder, it can also be used to bond ultra-hard materials such as tungsten carbide and boron nitride. In addition, for copper (Cu), silver (Ag)
The eutectic with tin (Sn) helps lower the melting point and is excellent in malleability, and the alloy with tin (Sn) also improves corrosion resistance. Furthermore, titanium is a type of active metal that is concentrated at the ceramic interface and ensures reliable bonding. On the other hand, silver (Ag) is concentrated near the bonding interface, forms a buffer layer in the bonding layer, and contributes to stress relaxation due to expansion and contraction. Also, copper (
When Cu) and tin (Ag) are made into an alloy, they are solid dissolved in titanium (Ti) and are thought to lower the melting point and improve wettability of the brazing material.

The metals of the above four components may be in the form of powder, foil or plate, and titanium may be in the form of hydride (TiN2). In addition, for tj4 (Cu) and tin (Sn), an alloy of both is preferable, and the weight composition ratio is copper (Cu):tin (Sn) =
(20-80%): (80-20%) is required. In such a Cu-Sn alloy, the melting temperature is about 920°C when the weight composition ratio Cu:Sn=80:20, and the weight composition ratio Cu:S
When n=20:80, the melting temperature is about 550°C. In addition, in addition, Ag-Cu type, Ag-5n type, A
g Various Cu-3ol alloys may be used.

In addition, when using a buffer material that contains each of the four component metals that make up the brazing material, or a material that includes each of the four components, the composition of the brazing material may be affected by diffusion in the bonding layer. However, the effect is that the part added to the composition is also included as one of the states of each of the four component metals. When used as a brazing material, a reaction layer of lθ to 40 AL is generated from the surface due to factors such as temperature and time, and Cu is eluted into other components (3 to 4 components) and becomes part of the brazing material component. The eluted portion is also considered to be in a metal state similar to the above-mentioned powder, foil, etc., and is also included in the composition range of the brazing material in the present invention.

Note that components other than the above four components, such as Fe and Mn.

Co or Cr'3 may be included in the buffer material. In addition, unavoidable impurities related to the purity of each of the four component metals may be added, and the fourth component may be affected in the bonding layer due to the diffusion of the ceramic components or auxiliary components that are the bonding base material. sell.

Regarding the heating atmosphere, since Ti is easily oxidized, 10-"
In a vacuum above tarr, in an orphan atmosphere or in hydrogen gas,
An inert atmosphere such as nitrogen gas or argon gas is required.

The heating temperature varies depending on the composition of the brazing material, but in the present invention, a range of 750 to 1000°C is suitable. In addition, there are no particular restrictions on the heating rate and cooling rate conditions in the present invention, and rapid heating and cooling (50°C/50°C, respectively)
(win or higher) is not supported, however, 10-20℃ at a temperature of 500-600℃ for removal and degassing.
It is desirable to provide a step of heating for a minute.

In the present invention, materials to be joined made of ceramics include metal oxide ceramics such as alumina ceramics, nitride ceramics such as silicon nitride, carbides, borides, spinels, forsterites, and the like. In addition, materials to be joined made of metal include ss, sc
, SK, SOS and other steels or special steels, as well as Xi-Cr, Fe-Ni, Fe-Ni
-Alloys such as Go and superhard materials (for example, WC) are also widely targeted. In addition, in joining the above ceramics,
It is not necessary to use it together with other brazing materials such as silver solder, and it is sufficient to use only the brazing material in the present invention, and the above-mentioned 4.
A copper buffer may be used, which is one of the following:

Based on the above, we conducted various experiments and summarized the results.
The weight composition of the brazing material is Ag: 10-40%, Cu:
8-58%, Sn: 8-58%, Ti: 5-25
The results showed that % was optimal.

〔Example〕

Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.

The ceramic plate and metal were joined in one operation.

As shown in Figure 1, the ceramic plate is 30×1
5X 5■/1 alumina plate (purity 33.5%, surface roughness 1-2 gRa) l, metal 545 with a thickness of 5 m/m
A C plate 2 was used, and a Cu plate 3 having a thickness of 2 mm and 111 mm was used as an insert material. First, metal powders of silver, copper, tin, and titanium (throughout 240 layers of esh) are weighed out to a predetermined mixing ratio and mixed thoroughly. Then, 1023.1 part of screen oil is mixed for 100 ii parts of the mixed powder. Next, the surface of the alumina plate 1 was excessively dried with ethanol, and then a paste was applied to the surface to a thickness of 60 gm. This is then processed into Cu as an insert material in a vacuum dryer.
Sandwich the plate 3 and place it in a vacuum (at about 950℃, use Cu-3n
In the case of soldering at 800° C., soldering material 4 of silver soldering (BAg-8) was used. The state of the bond at that time is shown in Figure 1.
FIG. 2 shows the results of EPMA of the cross section of the bonding layer.

In addition, in the figure, reference numeral 5 indicates a Ti and Sn concentrated area, and 6 indicates a Ti and Sn concentrated area.
In the Ag and Sn concentrated portion 7, the main rate of Cu regeneration is 0.51/win.

〔Effect of the invention〕

Since the present invention has the above configuration, it has become possible to join ceramics and materials to be joined at a low temperature. In addition, it is now possible to omit the plating process that was previously required, and it is possible to join with only -1 steps, making it possible to join with fewer steps than before. . Furthermore, it has become possible to join non-oxide ceramics such as silicon nitride, making it possible to join a wider variety of members to be joined. In addition, there is an effect that a bond with little variation and high reliability and corrosion resistance can be used.

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[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing a state in which ceramics and metal are bonded using the ceramic bonding method according to the present invention, and FIG. 2 is a bonding layer between the ceramic and the buffer material in the cross-sectional view shown in FIG. This is an EPMA composition image showing the crystal structure of , and is a photograph showing the distribution state of each component element. , l... Ceramics 2... Material to be joined (545C board) 4... Brazing material Patent applicant Sumitomo Cement Co., Ltd. S45C) 3--Lower wood (Cu version) 4--Raw wood (Koitomerikahosho (method) % formula % 1. Indication of incident 1985 Patent Application No. 257265 2. Invention Name of Hikoji Imayo (7519) Patent attorney Tsuchihashi Ko 5, Date of amendment order March 31, 1985 (old shipping date) 6, Number of inventions increased by amendment None 7, Amendment Target of
Contents of amendment in the column “Brief explanation of drawings” of the specification In lines 4 to 7 of page 11 of the specification, “Cross-sectional view shown,
FIG. 2 is an EPMA composition image showing the crystal structure of the bonding layer between the ceramic and the buffer material in the cross-sectional view shown in FIG. 1, and is a photograph showing the distribution state of each component element. " is corrected to "This is a sectional view shown."

Claims (1)

[Claims] 1) Ceramics and materials to be joined are bonded using a brazing material consisting of four components: silver (Ag), copper (Cu), tin (Sn), and titanium (Ti). Ceramics joining method. 2) The weight composition of the four components constituting the brazing material is silver (A
g) 10-40%, copper (Cu) 8-58%, tin (Sn)
8 to 56%, titanium (Ti) 5 to 25%, the method for joining ceramics according to claim 1. 3) Copper (Cu) and tin (Sn) among the four components constituting the brazing material are 20 to 80% copper (Cu) and tin (Sn).
n) The method for joining ceramics according to claim 1, wherein the ceramic and the material to be joined are joined using a Cu-Sn alloy having a weight composition ratio of 8.0 to 20%.