JPS58212879A - Ceramic-metal composite tubular body and its manufacture - Google Patents

Abstract

PURPOSE:To obtain a composite tubular body excellent in electric insulation, heat insulation and heat resistance, by connecting closely a metallic tubular body to inside of a machinable ceramic hollow body composed mainly of mica. CONSTITUTION:Outer diameter of a metallic tubular body such as copper etc. is made slightly larger than inner diameter of a mica ceramic hollow body 2, and cold pressed into the hollow part of the mica ceramic hollow body 2. As the mica ceramic is small in coefficient of friction, unbreakable and easy to shave, the metallic tubular body 1 can be pressed into the mica ceramic hollow body 2 smoothly. After pressing in, the two are connected firmly due to difference in coefficient of thermal expansion. A welding torch for high frequency arc welding using the composite tubular body does not cause abnormalities such as breakage of insulating part or separation of the copper tubular body and mica ceramic body.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a ceramic-metal composite tubular body and a method for manufacturing the same.

For example, in order to improve the electrical insulation and heat insulation properties of the outer layer of a metal tubular body such as a copper pipe, a metal composite tubular body is provided with a thermosetting resin layer such as Bakelite resin on the outer periphery of the gold WIkwJ tubular body. This metal composite tubular body is commonly used as a welding torch or burner nozzle for frequency arc welding. However, although thermosetting resins such as Bakelite 1-based resins have excellent electrical insulation and heat insulation properties and pose no particular problems, they have a drawback in terms of heat resistance. That is, for example, since the heat resistance and temperature of Bakelite resin is 200 to 300°C, the above gold 1iIII! When using the brass tubular body as a high-frequency arc welding torch,
This has the drawback that the resin layer is scorched and degraded by heat, resulting in damage to the resin layer.

In view of the above circumstances, the present inventors obtained a metal composite tubular body that has good electrical insulation and heat insulation properties, good heat resistance, is particularly suitable as a welding torch, and is easy to manufacture. As a result of various studies, we found that a specific hollow ceramic body on the outside of a metal tubular body was avoided.
This ceramic has a high heat-resistant concentration of about 1000°C, so it has extremely good heat resistance, and it has also been found that its electrical insulation and heat insulation properties are not inferior to Bakelite resins, and the present invention has been completed.

That is, the gist of the present invention resides in a ceramic-metal composite tubular body characterized in that a metal tubular body is tightly bonded to the inside of a machinable ceramic hollow body mainly made of mica, and a method for manufacturing the same.

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

In the ceramic-metal composite tubular body of the present invention, for example, as shown in FIG. 1(C) and FIG. 2(0), a metal tubular body 1 is tightly bonded inside a ceramic hollow body 2.

The methods of tight bonding include: ■ A method of tightly bonding by press-fitting the metal tubular body 1 into the hollow part of the ceramic hollow body 2 without using adhesives or binding agents; and the corresponding screws are installed on the outside of the metal tubular body 1. [Method of fixing the connection with screws] ■ In the method of @ above, the surface where the ceramic hollow body 2 and the metal composite tubular body are in contact is bonded with, for example, glass. Examples include a method in which an agent is present.

The shape and size of the metal tubular body 1 and the ceramic hollow body 2 are determined depending on their use (appropriately determined), but for example, the average wall thickness of the ceramic hollow body 2 is about 1 to 5 cm, It is about 2 to 10 times the wall thickness of the metal tubular body 1.

Examples of the metal tubular body 1 that can be used in the present invention include steel pipes, aluminum pipes, stainless steel pipes, and soft steel pipes, and among them, steel pipes are particularly desirable. Further, this tubular body 1 may be provided with, for example, threads, curved parts, protrusions, etc. as appropriate.
It is okay to have one.

On the other hand, as the ceramic hollow body 2, a machinable ceramic mainly composed of mica (hereinafter simply referred to as 1 mica ceramic) is used, and specifically, for example, fluorine phlogopite (KMOaAisi11010F2), potassium tetrasilicon 'Ij Mother (K M Q 2.5 S 14010F2
), natural mica powder and glass, phosphoric acid or 111al
Ceramics manufactured by mixing fluorine, gold, and glass and forming the mixture under high temperature and pressure, ceramics manufactured by mixing fluorine, gold, and glass, melting the mixture, and precipitating crystals, and mixtures thereof can be mentioned.

The ceramic-metal composite tubular body of the present invention is provided with a specific ceramic having an extremely high heat resistance temperature of about 1000° C. in its outer layer, and has not only excellent electrical insulation and heat insulation properties but also excellent heat resistance.

Therefore, the ceramic-metal composite tubular body of the present invention can be used in a wide variety of applications. For example, it is particularly preferable to use it for welding torches used in frequency arc welding, burner nozzles, porcelain pipes, and the like.

The characteristics of the ceramic-metal composite tubular body of the present invention include:
For example, there is a method in which a metal tubular body 1 as shown in FIG. 1(a) is press-fitted into a hollow portion of a ceramic hollow body 2 as shown in FIG. 1(b).

In this case, the outer diameter of the metal tubular body 1 is set to the ceramic hollow body 2.
Slightly larger than the inner diameter of, for example, 0.003 to 0.0
A preferred method is to increase the size by 5em, preferably 0.005 to 0.03+am, and press-fit it into the hollow part of the ceramic hollow body 2 in a cold state at, for example, -60 to -80°C. This method takes advantage of the characteristics of mica ceramic, which has a small coefficient of friction and is easy to soak, and is also easy to scrape without breaking. Therefore, the metal tubular body 1 can be press-fitted into the ceramic hollow body 2 smoothly. It can be carried out. Further, after press-fitting, since there is a difference in coefficient of thermal expansion between mica ceramic and metal such as copper, the ceramic hollow body 2 and the metal tubular body 1 are tightly and closely connected.

Further, in the ceramic hollow body-metal composite tubular body of the present invention, as shown in FIG. 2(a), a male thread is provided on the outside of the metal tubular body 1, and on the other hand, as shown in FIG. , a corresponding male screw is provided on the inside of the ceramic hollow body 2, and
It can be manufactured by applying glass to the surfaces where the two come into contact, then fitting the two together and subjecting them to heat treatment. In this case, the glass 3 applied to the surface where the ceramic hollow body 2 and the metal tubular body 1 come into contact is usually α=95 to 15
A material having a coefficient of thermal expansion of 0x10/'C is used, and the coating surface may be either the inside of the ceramic hollow body 2, the outside of the metal tubular body 1, or both. The heat treatment temperature after the two parts are fitted together is sufficient as long as the coated glass melts, and is usually 100 to 600°C, and the treatment time is about 60 to 1200 minutes. Through this heat treatment, the glass melts and solidifies between the metal tubular body 1 and the ceramic hollow body 2, forming an intermediate layer and fixing the two, so that, in combination with the screw connection, the two are tightly and tightly bonded. .

As described above, according to the present invention, by combining a specific ceramic hollow body and a metal composite tubular body, a composite tubular body having extremely excellent heat resistance, heat insulation, and insulation properties can be obtained. For example, welding torches, burners. It can be used for various purposes such as a nozzle. In particular, when the composite tubular body of the present invention is used as a welding torch, unlike welding torches made of conventional Bakelite resin-metal composite tubular bodies, the insulating layer may deteriorate due to heat and break. This is preferable because the drawbacks mentioned above can be completely eliminated. Further, the composite tubular body of the present invention can be easily manufactured by following the above-mentioned method, and has the advantage that it can be manufactured industrially at low cost.

Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to the description of the examples unless it exceeds the gist thereof.

Example 1 In Fig. 1, a copper tubular body (outside diameter 101
11 m, inner diameter 7.8 mm) was prepared, and a mica ceramic hollow body (outer diameter 14 Il 1 m, inner diameter 9
．． The composite tubular body shown in FIG. 1(C) was manufactured by press-fitting the tube into the hollow part of the tube (99vn) under a cold temperature condition of -80°C. The copper tubular body and the mica ceramic hollow body of this composite tubular body were tightly and closely bonded.

Example 2 Glass with a coefficient of thermal expansion α-120X10-7/'C was coated on the inside of a copper tubular body (outer diameter 10IR3 inner diameter 7.81111) that held a 1°II4 screw as shown in Fig. 2(a). This is a mica ceramic hollow body with a screw (outer diameter 14 sn, inner diameter 1011) corresponding to the structure shown in Fig. 2(b).
The mica ceramic was then heated at 150° C. for 30 minutes and then cooled to produce a composite tubular body as shown in FIG. 2(C). -17981 by the powder sintering method. The copper tubular body and the mica ceramic hollow body of the composite tubular body were tightly bonded.

Application Example A welding torch for high-frequency arc welding was manufactured using the composite tubular bodies manufactured in Examples 1 and 2, and the welding torches 1 to 2 were manufactured using the composite tubular bodies manufactured in Examples 1 and 2.
A 5-hour welding test was conducted using .

After the welding test, the condition of the welding torch was observed, and there were no abnormalities such as damage to the insulation section or separation between the copper tubular body and the mica ceramic hollow body.

[Brief explanation of the drawing]

FIG. 1(a) is a sectional view showing an example of a metal tubular body used in the present invention, FIG. 1(b) is a sectional view of a ceramic hollow body, and FIG. ) and Figure 1 (b
2(a) is a sectional view showing another example of a metal tubular body used in the present invention, and FIG. 2(e) is a sectional view of a composite tubular body formed from the members of The cross-sectional view of the hollow body, Fig. 2(c) is similar to Fig. 2(a) and Fig. 2(
It is a sectional view of the metal composite tubular body formed from the member of b). 1... Metal tubular body 2... Ceramic hollow body Agent Patent attorney Tsutomu Adachi Figure 1 (0) (b) Figure 2 (a) (b > 2 (C) ( c)

Claims (1)

[Scope of Claims] 1. A ceramic-metal composite tubular body, characterized in that a metal Il tubular body is tightly bonded to the inside of a machinable relamic hollow body mainly made of mica. 2. The ceramic-metal composite tubular body according to claim m1, wherein the ceramic-metal composite tubular body is a welding torch. -3 The ceramic-metal composite tubular body according to claim 1 or 2, wherein the metal tubular body is a copper tubular body. 4. A ceramic metal characterized by cold press-fitting a gold tubular body having an outer diameter slightly larger than the inner diameter of the hollow body into the inside of a machinable ceramic hollow body mainly made of mica. Method for manufacturing a composite tubular body. 5. The method for producing a ceramic-metal composite tubular body according to claim 4, wherein the cold press-fitting temperature is -60 to -80°C. 6. Production of a ceramic-metal composite tubular body according to claim 4 or 5, wherein the outer diameter of the metal tubular body to be cold press-fitted is 0.003 to 0.051 larger than the inner diameter of the ceramic hollow body. Law. 7 Glass was applied to the outside of the metal tubular body, and a machinable ceramic hollow body mainly made of mica and having an inner diameter slightly larger than the outer diameter of the tubular body was fitted onto the outside of the glass. A method for producing a ceramic-metal composite tubular body, which is characterized by subsequent heat treatment. 8 The glass to be coated is α-95 to 150 x 10-'
8. The method for producing a ceramic-metal composite tubular body according to claim 7, which has a coefficient of thermal expansion of /°C. 9. A method for producing a ceramic-metal composite tubular body according to claim 7 or 8, wherein the temperature of the heat treatment is 100 to 50°C (5°C). 10 A patent claim in which the metal tubular body has a male thread on its outer periphery. A method for producing a ceramic-metal composite tubular body according to any one of items 7 to 9.