JP3501834B2 - Manufacturing method of joined body of ceramic material and metal material - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is suitable for joining a ceramic material and a metal material, particularly for joining a tubular body (including a tubular body) in general, and has excellent airtightness, electrical insulation and joining. It can be used in all fields where strength and the like are required, such as a lead-out terminal, an airtight container, and an insulator tube.

[0002]

2. Description of the Related Art A method of joining a ceramic material and a metal material by brazing has been conventionally practiced. However, satisfactory results have been obtained in terms of airtightness, bonding strength, etc., because the thermal expansion coefficient of Fernico alloys and 42Ni-Fe alloys known by the trade name "Kovar" is relatively close to that of ceramics. It is limited to metal materials such as alloys and copper that are very flexible and easily plastically deformed. Then, when a metal material having a large thermal expansion coefficient such as stainless steel and high rigidity is brazed to the ceramic material, the shrinkage stress generated during cooling after brazing causes cracks in the brazing portion of the ceramic material, Good results have not been obtained due to scratches and the like.

[0003]

DISCLOSURE OF THE INVENTION The present invention solves the above problems, and has excellent airtightness even if it is a metal material having a large difference in coefficient of thermal expansion from a ceramic material such as stainless steel. An object of the present invention is to provide a method of manufacturing a bonded body of a ceramic material and a metal material, which realizes bonding strength, magnetic properties, durability, and the like, and in which internal stress hardly remains in the bonded body .

[0004]

DISCLOSURE OF THE INVENTION As a result of various investigations by the inventors of the present invention, various methods of joining a ceramic material and a metal material, in particular, a method for producing a joined body of a ceramic material and a metal material having a large difference in coefficient of thermal expansion. , At the time of heat bonding, a brazing material layer made of a brazing material,
By forming on the ceramic material surface of the overlapping portion of the ceramic material and the metal material, and the protruding portion beyond it, and by joining by thinning the wall thickness of the metal material in the vicinity of the joining portion,
The inventors have found that this drawback is eliminated, and have completed the present invention.

That is, the method for producing a joined body of a ceramic material and a metal material according to the first aspect of the present invention is a method for producing a joined ceramic material that is a tubular body.
A method for joining a metallic material, which is a tubular body made of stainless steel, by using a brazing material, the method comprising:
The peripheral surface is superposed on the inner peripheral surface of the end of the metal body, and at the time of heating and joining , the brazing material layer made of the brazing material has a superposed portion of the ceramic material and the metallic material, and a protruding portion beyond the superposed portion ( (Length; 1.0 mm or more) is formed so as to cover the surface of the ceramic material, and the metal material is joined.
The thickness of the portion is 0.5 mm or less. A second aspect of the invention is characterized in that a metallized layer is formed on the surface of the ceramic material in the overlapping portion and the protruding portion.

The length of the "protruding portion" may be determined by the difference in the coefficient of thermal expansion between the ceramic material and the metal material, the rigidity of the metal material, etc. The larger the difference in the coefficient of thermal expansion, the higher the rigidity. It is preferable that the length is as long as possible. This length needs to be 1.0 mm or more, and if it is less than that, stress is not sufficiently dispersed. Also, about 5 mm is sufficient for practical use, but depending on the size and shape of the material to be joined, it may be 10 to 20 m.
It may be in the range of m. If it exceeds 20 mm, no particular problem occurs, but no further effect can be obtained. In the method for manufacturing a joined body according to the present invention, the raw material may be the minimum amount necessary to secure the length of the protruding portion, and by reducing the low volume of the joined portion from the usual case. , The amount of the brazing material layer formed on the surface of the ceramic material beyond the end of the joining surface of the metal material is minimized, and the flow of the brazing material to unnecessary portions is suppressed to prevent the ceramic material from breaking. It is preferable to prevent the occurrence more reliably.

Further, in order to make the protruding portion have the above length, the ceramic material and the ceramic material are considered in consideration of the kind of the brazing material, the brazing temperature, the degree of wetting between the brazing material and the ceramic material, the gap between the materials to be joined, and the like. The volume of the raw material provided on the bonding surface of the metal material may be adjusted. In addition, in the case of the second invention, since the raw material wets the metallization layer very well, the tip of the raw material is located at substantially the same position as the tip of the metallized layer, and the length of the protruding portion depends on the length of the metallized layer. I can decide.

The above-mentioned "wall thickness at the joint portion of the metal material" is "0.5 mm or less". If the thickness exceeds 0.5 mm, the metal material is less likely to be plastically deformed, and the shrinkage stress generated during cooling after brazing cannot be sufficiently absorbed. A thinner metal material is preferable in terms of stress absorption, but if it is too thin, the strength as a structural material cannot be maintained, so even a highly rigid metal material such as stainless steel has a thickness of about 0.2 mm or more. In addition, since a metal material having low rigidity such as copper is easily plastically deformed, it may be thicker than stainless steel or the like in consideration of the strength of the structural material.

Further, in the first invention, the ceramic material and the metal material are cylindrical bodies, the metal material is made of stainless steel, and the outer peripheral surface of the end portion of the ceramic body is inside the end portion of the metal body. Characterized by being polymerized and bonded to the peripheral surface,
In a third aspect of the invention, the ceramic material is mainly composed of Al ₂ O ₃ , the metal material is made of stainless steel,
The metallized layer applied to the surface of the ceramic material,
A joint portion of the metal material formed so as to cover the ceramic material surface of the ceramic material and the metal material, and the protruding portion (length: 1.0 mm or more) beyond the polymerized portion. Has a wall thickness of 0.2 to 0.5 mm, the ceramic material and the metal material are tubular bodies, and the outer peripheral surface of the end portion of the ceramic body is superposed on the inner peripheral surface of the end portion of the metal body. , Which are joined together. The length of the protruding part and the joint part of the metal material
The reason for limiting the wall thickness is the same as in the case of the first invention.

As the material of the above-mentioned "ceramic material" to which the method for manufacturing a joined body of the present invention can be applied, oxide ceramic materials such as alumina and mullite, nitride ceramic materials such as silicon nitride and sialon, and silicon carbide. Examples of such a ceramic material include a ceramic material such as a carbide-based ceramic material and a single crystal such as sapphire.
Further, as the above-mentioned “metal material”, a material having a large coefficient of thermal expansion such as stainless steel (the coefficient of thermal expansion at 20 ° C. is 1 ×
^{10 -5} ~2 × 10 ^-5 ℃ about ^-1) and the like.

As the above-mentioned "raw material", those which are usually used can be used without particular limitation. For example, A
l, Ag-Cu, Au-Cu, Pt-Cu, Pd-C
u, Pb—Sn—Zn—Sb system or other metal material system, or T
i-Ni, Ti-Cu, Zr-Ni, the active metal material systems such as _{Be-Cu, TiH 2 -Ni,} TiH 2 -Cu, ZrH
_In addition to hydrides such as _2- Ni, B ₂ O ₃ -P
_{bO-ZnO, B 2 O 3} -PbO-SiO 2, B 2 O 3
-ZnO-SiO ₂ , low melting point oxide system, Al ₂ O ₃ , M
Examples thereof include highly heat-resistant oxides containing gO, CaO, ZrO ₂ or the like as a main component.

As the metallizing material for forming the above-mentioned "metallized layer", those which are usually used can be used without any particular limitation. For example, Mo-Mn, Mo-Mn-T.
i, W-Mn, W- Mn-Ti, Mo-SiO 2, Mo
_{-CaO-SiO 2, Mo-MnO} 2 -TiO 2, W-
_{SiO 2, W-CaO-SiO} 2, W-MnO 2 -Ti
_{O 2, Mo-MnO 2 -TiO} 2 -SiO 2, W-Re
Include those of the series of such -MnO ₂ -TiO _2.
In the present invention, the raw material and the metallized material may be appropriately selected and used depending on the types of the ceramic material and the metal material.

[0013]

According to the method of the present invention, the brazing material layer is formed on the surface of the ceramic material beyond the portion where the ceramic material and the metal material are superposed, and that portion is, as shown in FIG. The portion has a substantially triangular cross-section formed by the surface of the ceramic material and the tip of the brazing material layer facing it. Therefore, during cooling, the stress generated due to the difference in thermal expansion coefficient is not concentrated in the vicinity of the tip of the metal material, but is widely dispersed in the brazing material layer. In addition, the thickness of the metal material should be made as thin as 0.5 mm or less at least in the vicinity of the joint, and should be a thickness that can absorb the shrinkage stress generated during cooling after brazing, depending on the rigidity of each metal material. With this, in combination with the effect of stress dispersion of the brazing material layer, cracks, cracks and the like at the brazing part of the ceramic material are prevented from occurring, and a bonded body excellent in airtightness, strength, durability and the like can be obtained.

The material to be joined by the method of the present invention is not particularly limited, but especially when the difference in the coefficient of thermal expansion between the ceramic material and the metal material is large, or the rigidity of the metal material is high. It is suitable. When the difference in the coefficient of thermal expansion between the ceramic material and the metal material is small, for example, when a Fernico alloy or a 42Ni—Fe alloy is used as the metal material, cracks, cracks, etc. do not occur even with the conventional method. rare. However, the stress generated at the time of shrinkage remains, which has a considerable adverse effect on the durability and the like of the bonded body, and it is preferable to apply the method of the present invention because the residual stress is reduced. In addition, when the metal material has low rigidity like copper, stress is absorbed by plastic deformation of itself, so that cracks and the like are less likely to occur even without the method of the present invention. Also, since stress remains in the bonded portion, the durability of the bonded body is deteriorated as in the above case, and it is preferable to bond by the method of the present invention.

Further, the method of the present invention exerts a particularly great effect when the ceramic material and the metal material are tubular bodies. If both are flat, it is relatively easy to deform and displace, and strain and stress are easily absorbed, so joining is relatively easy, but both are cylindrical bodies, especially the outer peripheral surface of the end of the ceramic body. When a metal body, especially stainless steel, has a large difference in coefficient of thermal expansion from a ceramic material and is superposed on the inner peripheral surface of the end of a cylindrical body made of a metal material having high rigidity, the metal is cooled during cooling. Since the inner diameter of the body becomes small and the ceramic body is tightened, a large external force is applied to the ceramic body, and the ceramic body is apt to be cracked or broken, so that the present invention is preferably applied.

[0016]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples. 1 is a vertical cross-sectional view of a joined portion of a joined body of Example 1, and FIG. 2 is that of a joined body of Comparative Example 2. 1 and 2 and 3, reference numeral 1 denotes a joint portion, 2
Is a ceramic tubular body, 3 is a stainless steel tubular body, 4
Is a polymerized portion, and 5 is a brazing material layer. In FIGS. 1 and 3, 6 represents the brazing material layer in the protruding portion, and L represents the length of the protruding portion. [Brazed test] Ceramic material with an outer diameter of 40 mm (main component:
A Mo—Mn-based metallizing paste was applied to a required portion of the outer peripheral surface at one end of a tubular body 2 made of Al ₂ O ₃ (92%), and the paste was baked in a hydrogen furnace. Then, Ni plating (neither is shown) was applied to the surface of the generated metallized layer. Next, stainless steel with an inner diameter of about 40 mm (SU
The metallized portion of the above ceramic body is inserted into the tubular body 3 made of S316) with brazing (raw material: 72Ag-C).
u). Table 1 shows the thickness of the stainless steel body at the joint portion 1 at this time, the length L of the brazing material layer protruding from the end portion, and the result of brazing. Brazing under each condition was performed 10 times.

[0017]

[Table 1]

According to the results shown in Table 1, the thickness of the stainless steel body at the joint was 0.3 mm, and the length of the protruding portion of the brazing material layer on the surface of the ceramic body was 1.5 mm. Then, as shown in FIG. 1, the thickness of the metal body at the joint portion is thinner than other portions, and the brazing material layer crosses over the polymerized portion and is formed on the surface of the ceramic body in a cross section as shown in FIG. Since it is formed in a triangular shape, the ceramic body is not cracked at all. On the other hand, in Comparative Example 1 in which the thickness is 0.5 mm and the thickness is as it is, cracking occurs 6 times, and as shown in FIG. 2, the thickness of the metal body is completely different between the joined portion and other portions. In Comparative Example 2 where the protrusion length of the brazing material layer was 0.5 mm and the protrusion length was slightly over 0.5 mm, cracks occurred in all 10 times. In addition, the protruding length is 1.5 m as in the embodiment.
Although the thickness is m, in Comparative Example 3 in which the metal body has a large thickness of 0.8 mm, four cracks occurred.

From the above results, in the method for manufacturing a joined body according to the present invention, the wall thickness of the metal body in the joined portion is made small, and the brazing material layer has a required length on the surface of the ceramic body. It can be seen that the ceramic material is prevented from cracking, breaking and the like by forming the ceramic material by leaving it. The present invention is not limited to the specific examples described above, and various modifications may be made within the scope of the present invention depending on the purpose and application.

[0020]

EFFECTS OF THE INVENTION Conventionally, a metal material which can be directly brazed to a ceramic material is one having a thermal expansion coefficient relatively close to that of a ceramic material such as Fernico alloy, 42Ni-Fe, or a very soft plastic material such as copper. Although it is limited to the one that is easily deformed, according to the method for manufacturing a joined body of the present invention, a metal material that has a large coefficient of thermal expansion as compared with a ceramic material such as stainless steel and that has high rigidity and is not easily plastically deformed. Even in this case, it is possible to obtain a bonded body having excellent airtightness, bonding strength, magnetic properties, heat resistance and the like.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a joint portion between a tubular body made of a ceramic material and a tubular body made of stainless steel joined by the method of the present invention.

FIG. 2 is a vertical cross-sectional view of a joint portion between a tubular body made of a ceramic material and a tubular body made of stainless steel joined by a conventional method.

FIG. 3 is an enlarged vertical sectional view of the vicinity of a protruding portion of the brazing material layer of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1; Joining part, 2; Cylindrical body made of ceramic material, 3; Cylindrical body made of stainless steel, 4; Polymerization part, 5; Brazing material layer provided in the polymerization part, 6; Brazing material layer, L; length of the brazing material layer formed beyond the overlapping portion

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References Japanese Patent Laid-Open No. 2-196074 (JP, A) Japanese Patent Laid-Open No. 3-261669 (JP, A) Actually Opening 4-89527 (JP, U) Actual Public Sho-46- 29954 (JP, Y1) (58) Fields investigated (Int. Cl. ⁷ , DB name) C04B 37/00-37/04 B23K 1/00-7/10

Claims (3)

(57) [Claims] 1. A cylindrical ceramic material and stainless steel.
A method for manufacturing a joined body, in which a metal material, which is a tubular body made of steel, is joined by using a raw material, wherein an outer peripheral surface of an end portion of the ceramic body is inside an end portion of the metal body.
The brazing material layer, which is polymerized on the peripheral surface and is bonded by heating, is a superposed portion of the ceramic material and the metallic material,
A protruding portion (length: 1.0 mm beyond the above-mentioned overlapping portion
The above is formed so as to cover the surface of the ceramic material and the thickness of the joint portion of the metal material is 0.5 mm.
Of the ceramic material and the metal material characterized by the following
Method for manufacturing joined body . 2. A joined body of a ceramic material and a metal material according to claim 1, wherein a metallized layer is formed on the surface of the ceramic material in the overlapping portion and the protruding portion .
Build method. 3. The ceramic material is mainly composed of Al ₂ O ₃ .
The above metal material is made of stainless steel.
The metallization layer applied to the surface of the ceramic material
Is a polymerized portion of the ceramic material and the metal material, and the polymerized portion
The above-mentioned protrusion beyond the minute (length: 1.0 mm or more)
Formed to cover the surface of the ceramic material,
The thickness of the joint portion of the metal material is 0.2 to 0.5 mm
And the ceramic material and the metal material are tubular bodies.
And the outer peripheral surface of the end of the ceramic body is the end of the metal body.
The method for producing a joined body of a ceramic material and a metal material according to claim 1, wherein the joined body is polymerized and joined to the inner peripheral surface .