JP3004379B2 - Joining method of ceramics and metal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of joining ceramics and metal, and more particularly to a joined body of ceramics and metal used in Na, for example, an insulating part of a fast breeder reactor, a Na battery,
The present invention relates to a method for joining a ceramic and a metal which can be advantageously applied to the production of an electrode portion of a Na thermoelectric power generation system.

[0002]

2. Description of the Related Art Conventionally, there has been the following method for producing a joined body of ceramic and metal used in Na. (1) After metallizing the ceramic surface by the Mo · Mn method, it is joined to the metal with a brazing material mainly composed of Ni. (2) Ceramics and metal are joined with a brazing filler metal containing Ti as a main component.

[0003]

In the Mo · Mn method, Mo and Mn are used.
The powder was mixed with an organic binder, applied to the ceramic surface, and heated to 1400 to 1500 ° C. in a humidified hydrogen atmosphere to form a Mo, Mn film and then Ni plating.
Although it is a method of brazing to a metal, such a process is complicated, and since there is a process of passing through moisture or a plating solution, β, β ″ -Al ₂ O ₃ that reacts with water has I can not use it.

[0004] The melting point of the brazing material containing Ti as a main component is 11
Since the temperature is as high as 00 ° C. or higher, a large thermal stress is generated between the ceramic and the metal, and the ceramic may be cracked.
Further, since Cu is generally contained, a phenomenon in which Na and Cu react and the brazing material is eluted is also observed.

The present invention has been made in view of the above-mentioned state of the art, and has as its object to provide a method of joining ceramics and metal, which does not cause problems as in the conventional method.

[0006]

The present invention is used in Na.
In producing a joined body of ceramic and metal,
An active metal foil is placed on the surface in contact with the ceramic to be joined, and Ni is placed between the active metal foil and the metal to be joined.
After placing a brazing filler metal containing no Au, Ag, and Cu as main components, these members are heated to a temperature equal to or higher than the melting point of the brazing filler metal in a vacuum or inert gas atmosphere. It is a joining method.

That is, according to the present invention, when manufacturing a joined body of ceramic and metal used in Na, an active metal foil such as Ti is arranged on a surface in contact with the ceramic,
A brazing material is disposed between the active metal foil and the metal, and the brazing material is composed of Ni as a main component and containing no Au, Ag, and Cu at all. The heating is performed in a vacuum or an inert gas at a temperature higher than the melting point of the brazing material to melt the brazing material and join the ceramic and the metal.

In the present invention, the surface in contact with the ceramic is made of Ti
An active metal foil such as that described above is arranged, and this plays a role in improving the bondability between the brazing material and the ceramic. In other words, the active metal has a strong reducing property, and when heated above the melting point of the brazing material while in contact with the ceramic in a non-oxidizing atmosphere such as vacuum or an inert gas, only the very surface of the ceramic is reduced and the brazing material is reduced. Creates a condition that is easy to get wet.

As a brazing material for joining ceramics and metal, a material mainly containing Au, Ag and Cu is usually used. In the present invention, Ni is used as a main component and A is used as an additional component.
Contains no u, Ag, or Cu. This is Au, Ag, C
Since u has a high solubility in Na, when a brazing filler metal containing these elements is used, a phenomenon in which the brazing filler component dissolves during use in Na and then peels off is observed, as in the present invention. By using a brazing material containing Ni as a main component and containing no Au, Ag, or Cu, it can withstand long-term use in Na.

A specific embodiment of the present invention will be described with reference to FIG. In FIG. 1, an active metal foil 3 and a brazing material 4 are arranged between a ceramic 1 and a metal 2 which are members to be joined from the ceramic side. Al ₂ as ceramics 1
In addition to oxide ceramics such as O ₃ and ZrO ₂ , Si
₃ N _4, SiC, etc. non-oxide ceramics may also be used. As the active metal foil 3, metals made of an element having a strong affinity for oxygen, such as Ti and Zr, and alloy foils containing these as main components can be used. The brazing filler metal 4 is mainly composed of Ni, Au,
A brazing alloy containing no Ag or Cu. For example, Ni-
Ni-P system such as 11% P, Ni-7% Cr-4.5% Si-3
Ni-Cr-Si-Fe-B system such as% Fe-3% B, Ni-19%
A Ni-Cr-Si system such as Cr-10% Si can be used.

When the combination thus obtained is heated in a vacuum or inert gas to a temperature higher than the melting point of the brazing material 4 by the heater 5, the active metal foil 3 reduces only the very surface of the bonding surface of the ceramics 1. As a result, the molten brazing material 4 wets the surface in the activated state, so that good wettability is exhibited and bonding is performed over the entire bonding surface.

At this time, it is needless to say that the thickness of the active metal foil 3 is important, and it is needless to say that the thickness of the active metal foil 3 is not less than the amount required for reducing the ceramics 1, but the excess amount of the active metal foil 3 is not less than the amount necessary for reducing the ceramics 1. Must be dissolved in the brazing material 4, so the upper limit is determined from this point. Considering this point, the active metal foil 3 needs to be 1 μm or more, and the thickness of the brazing material 4 is 2 μm.
Desirably, it is 0% or less.

Hereinafter, the present invention will be described in detail with reference to examples.

【Example】

(Example 1) 99.5% pure Al as ceramics
Using Fe ₂ O ₃ (diameter 20 mm, thickness 10 mm) as metal
A 29% Ni-17% Co alloy (diameter 20 mm, thickness 10 mm) was used for joining. A pure Ti foil having a thickness of 6 μm and a diameter of 20 mm is provided on the side in contact with the ceramic, and a Ni-7% Cr-4.5% Si-3% Fe-3% B component is provided between the metal and this. A brazing material having a thickness of 50 μm and a diameter of 20 mm was arranged and set in a vacuum furnace. The joined body was brazed in a vacuum of 1 × 10 ⁻⁵ Torr at 1050 ° C., which is 50 ° C. higher than the melting point of the brazing material, for 10 minutes. The brazing portion had good external appearance with good wettability of the brazing material, and no defect was observed in the cross-sectional inspection.

Such a conjugate is placed in Na at 500 ° C. for 10 minutes.
After immersion for 00 hours and removal, no peeling or melting of the brazing material was observed, and the shear strength at the brazed portion was 5 kg / mm ² or more.

(Example 2) ZrO ₂ as ceramics
-8% Y ₂ O ₃ component, outer diameter 24mm, inner diameter 18mm, length 1
A pipe with a diameter of 00 mm and a closed end was used. The metal was Fe-29% Ni-17% Co alloy, having an outer diameter of 24 mm and an inner diameter of 1 mm.
It was used for joining using a pipe of 8 mm and a length of 50 mm. Between them, on the side in contact with the ceramic, a thickness of 10 μm and an outer diameter of 24
mm, Zr foil with an inner diameter of 18 mm and Ni-19 between this and metal
A brazing material having a composition of% Cr-10% Si, a thickness of 100 μm, an outer diameter of 24 mm and an inner diameter of 18 mm was arranged and set in a vacuum furnace. After evacuating the vacuum furnace to 1 × 10 ⁻⁵ Torr, Ar was sealed at 1 atm and heated at 1200 ° C. for 50 minutes higher than the melting point of the brazing material for 10 minutes while flowing at a flow rate of 5 l / min. Was done. The brazing portion had good wettability of the brazing material in appearance, and a He leak test was performed. As a result, 1 × 10 ⁻⁹ A · cc was obtained.
/ Sec or less.

The outside of such a joined body is immersed in Na,
It was used for 500 hours at 500 ° C. with N ₂ flowing inside, but no leak was seen and the condition was sound.

[0017]

According to the present invention, the following effects are obtained. This is a simple method that can be joined in one step. Na
Since it does not contain Au, Ag, and Cu that dissolve in water, it is stable even when used in high-temperature Na for a long time. Since there is no process of passing through moisture and liquid, it can be used for β or β ″ alumina that reacts with moisture. The present invention is applicable not only to the joining of ceramics and metal, but also to the joining of ceramics together. I can do it.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an embodiment of the present invention.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C04B 37/02

Claims (1)

(57) [Claims] 1. A ceramic and a metal used in Na
In manufacturing the joined body , an active metal foil is arranged on a surface in contact with ceramics to be joined, Ni is a main component between the active metal foil and the metal to be joined, and Au, Ag, Cu
A method of joining ceramics and metal, comprising: arranging a brazing material that does not include any brazing material, and then heating these members in a vacuum or an inert gas atmosphere to a temperature equal to or higher than the melting point of the brazing material.