JPH07108824B2 - How to join carbon materials - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for joining carbon materials, and more particularly to a carbon-based material containing 0.2% by weight or more of free carbon, such as carbon materials, carbides and metals (hereinafter referred to as “carbon materials”). Abbreviated as carbon material),
The present invention relates to a method for joining the carbon material, the carbide or the metal.

[Conventional technology]

Carbon materials have wide characteristics and are widely used in industrial applications.

The form is generally defined as a carbon material, but more specifically, as graphite alone, carbon alone, a carbide with various metals, or a composite material containing these or a metal containing a large amount of carbon. It is usually used.

For example, graphite alone is used as a structural material for nuclear fission reactors and fusion reactors because of its excellent heat resistance and thermal shock resistance at high temperatures, and has high thermal conductivity and good lubricity. From a certain point of view, it is used as a casting mold sleeve, a hot press mold because of its excellent high-temperature strength, and a sputtering target and a material for internal structure of a semiconductor manufacturing apparatus because of its high conductivity.

In addition, the carbon-only material is used as a lining material of a chemical device due to its corrosion resistance, or as an electric brush material suitable for its electric resistance. However, in these applications, metal fittings that attach such carbon materials in place,
There is a problem such as joining with metal wiring for passing electricity.

As the carbide, for example, titanium carbide is used as a main component of hard heat-resistant alloys such as cermet in that it is excellent in high-temperature strength, silicon carbide pays attention to its corrosion resistance, heat exchanger partition walls, and tans stencarbite is Because of its high hardness, it is used for chip materials, cam contact parts, die materials, piston heads and the like.

Further, in the case of a composite material, a carbon base is impregnated with a metal having a high electric conductivity to form an electric brush utilizing lubricity and conductivity, or carbon and a resin are combined to form a sealing material or an electric discharge machining electrode material. It is used as

In this way, the applications of carbon materials are wide and steady.
Although it is expanding, there are still some problems to be solved before actually promoting industrialization.

In general, the demand for large-scale and high-performance industrial equipment is increasing day by day.
It is not always easy because there are restrictions on the characteristics of the manufacturing equipment or the functions of each material. Further, even if a casting mold having a complicated shape is made by a so-called near shave, there is a limitation in its work forming.

In addition, even if the characteristics of carbon materials are fully utilized, there are many cases where even higher characteristics are required. For example, in nuclear fuel reactors and structural materials for fusion reactors, the thermal load on graphite as a structural material is large, Although forced water cooling may be necessary, water cooling of the graphite material itself is impossible due to its water permeability,
Combination with water cooling metal pipes is required.

In many cases, the characteristics of a carbon material that is expected during use need only be in the front (back) surface layer, and in the base layer below (upper) the front (back) surface layer, A material different from the (back) surface layer may be used. Further, it may be necessary to join metal fittings for attaching the carbon material at a predetermined position or metal wiring for passing electricity to the carbon material.

The most common means for satisfying such a requirement is to bond a carbon material and another metal material, or carbon materials together, and to provide the above-mentioned functions by this bonding and to deal with them by a comprehensive composite function.

From such a demand, various methods have been conventionally proposed for joining materials of the same kind.

However, all of the various conventional joining methods have insufficient joining strength, or there are restrictions on the heating temperature or the like depending on the joining material, or many operations require complicated labor and time, Especially when joining large materials (generally having a small linear expansion coefficient), due to the difference in expansion coefficient between carbon material and large metal material, cracks and the like do not necessarily spread as a general-purpose technology and are still satisfactory. There are very few ways to do it.

[Problems to be Solved by the Invention]

The problem to be solved by the present invention is that this kind of carbon material or carbon material and metal material can be bonded to each other with great ease in bonding strength, heat resistance, impact resistance and corrosion resistance, and particularly large materials. However, it is to develop a new joining method capable of joining.

[Means for Solving the Problems]

When joining (A) a carbon material containing 0.2% by weight or more of carbon, and (B) a metal or the above carbon material (excluding the joining of carbon steels), (C) the linear expansion coefficient is 7 × 10. ^A metal or (and) a metal alloy having a temperature of ^-6 / ° C or less is used as an insert material, and (D) a carbon material and an insert material (C) are interposed with iron or an iron alloy, and (E) copper is added. The problem is solved by using copper or a copper alloy containing at least 25% by weight or more as a joining material for joining.

[Operation and Configuration of Invention]

In the present invention, in the joining of the carbon material (A) and the carbon material (B) or the carbon material (A) and the metal (B), a linear expansion coefficient (hereinafter abbreviated as CTE) is provided between them. Use an insert material (C) in which an iron layer (film) is deposited on the surface of a metal material of 7 × 10 ⁻⁶ or less, and further in joining, at least copper is provided on both surfaces of the insert material (C). A bonding material (E) made of copper or a copper alloy, which is contained in an amount of 25% by weight or more, is interposed, that is, heating is performed in a state of a combination of AEDECEDB, and (A) and (B) are It is based on joining.

Further, the operation and configuration of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an example of joining a carbon material (A) and a carbon material (B), using an insert material (C) having iron layers (1) and (2) on both sides and copper on both sides. It is what simulatedly illustrated the example which joins by interposing the containing bonding material (D).

FIG. 2 is an example of joining a carbon material (A) and a metal (B). An insert material (C) having an iron layer (1) on the surface facing the carbon material is used, and copper is contained on both sides. This is an example of joining with the joining material (D). In this case, even if iron layers are formed on both surfaces of the insert material (C), the same effect is exhibited.

In this case, the carbon materials (A) and (B) are carbon materials containing 0.2% by weight, preferably 0.5% by weight or more of free carbon, and of course do not include hydrous carbon or hydrocarbons. Here, the carbon material containing 0.2% by weight or more of free carbon is a carbon material that substantially contains 0.2% by weight or more of free carbon at the time of joining, and does not necessarily contain the above amount of free carbon before joining. Both good. For joining, the difference from the carbon content in the iron foil requires a concentration difference of at least 0.2% by weight or more, so if it is 0.2% by weight or less, there is no bridging effect with the carbon body and it is weak. , Sufficient bonding strength is not exhibited.

Specific examples thereof include graphite alone, carbon alone, a mixture of both, carbides of various metals, and composite materials with other materials containing at least one of these as other components, and other various ceramics. It is also possible to use a metal containing a predetermined amount of free carbon. The free carbon is not a compound but a single carbon.

As carbides of various metals, tungsten carbide,
In addition to titanium carbide and silicon carbide, other examples such as carbon steel and various alloy steels can be exemplified as preferable examples, and as the composite, carbon material reinforced with carbon fiber, so-called c / c composite material, carbon material Preferred specific examples include those impregnated and permeated with a metal, for example, those obtained by melting and impregnating a carbon material with iron, steel or the like at high temperature, or by mixing and pressing.

Next, a wide variety of metals are included as the metal material (B) to be bonded, and alloys are also included as the metals. Preferred metals include, for example, copper, tansten, molybdenum,
Examples include iron, silicon, stainless steel, Hastelloy, Inconel, carbon steel, various alloy steels, and iron alloys.

The carbon material and the metal material to be bonded are not limited in shape and size as long as the materials are those described above, and those having an appropriate shape and size are used.

The insert material (C) is used in joining these carbon materials together or in joining the carbon material and the metal material.

The insert material (C) may be any metal material having a CTE of 7 × 10 ^-6 ℃ or less, and for example, molybdenum, iron-molybdenum alloy plate, piece, thin plate, foil, etc. are used. A material having an iron layer on at least one surface thereof is preferably used as the material. The thickness of the insert material (C) is made thicker as the difference in expansion coefficient between the mating material, that is, (A) and (B), becomes larger, and sometimes becomes 1 m / m or more.

In the present invention, it is not always necessary to previously form the iron layer, and an iron foil piece may be simply interposed, but it is preferable to previously form the iron layer on the metal in terms of work efficiency.

As this iron layer, if it is in a state of being adhered uniformly,
It may be attached by any method. For example, an electroplating method, a chemical plating method, a vapor deposition method, a CVD method, a metal spraying method and the like can be mentioned.

The thickness of this iron layer is usually 1 m / m or less, particularly preferably 0.2 m / m.
It is the following.

When joining a carbon material (low CTE) and a metal material (high CTE), a molybdenum foil that is very close to the CTE of the carbon material should be interposed as a buffer layer between the two to make a joint.
No. 258155. However, when only molybdenum is used as in this known method, there is no bonding effect or the bonding effect is weak, and practically low. Therefore, a brazing foil such as nickel, titanium, or copper, a thin plate, or the like is further used above and below the molybdenum to cause a bridging effect, which is a practical joining technique. On the other hand, the present invention is characterized in that a metal having a CTE of 7 × 10 ⁻⁶ ° C. or less, for example, a metal such as molybdenum, is used in combination with iron, and a copper layer is further provided.

Although this iron layer is technically good even if it uses a foil-like one, it improves the work efficiency, reliability, and
It is particularly preferable to previously provide an iron layer on molybdenum or the like as described above in order to reduce costs. In particular, when a curved surface material, a profiled material, a precision processed material, or the like is bonded, it is extremely important to provide an iron layer in advance, and the iron layer can be reliably provided.

In the joining work, the insert material (C) with the iron layer provided or with the iron layer interposed is further coated with copper such as copper plate or copper foil.
% In the presence of the bonding material (D), preferably sandwiching both surfaces and heating under reduced pressure. That is, in the above work, the carbon material (A) -copper-iron-Mo-iron-copper- (B) is joined in an array, and especially the iron layer is a [carbon-copper-iron- (copper) alloy. Are crystallized and a strong bond is maintained. In this case, the iron foil can be provided with a large number of pores, and there is also a method in which copper flows between the Mo and iron through the pores to directly form a strong bonding layer.

The present inventors have previously stated that "when joining a carbon material containing 0.2% by weight or more of free carbon and the carbon material or a metal material, an interposing of a joining material containing at least 25% by weight of copper is used. , And a patent has already been filed (Japanese Patent Application No. 63-120105).

This invention is [carbon material-copper-iron foil-copper-carbon material or metal]
The main idea is to join the carbon materials by the arrangement of, and it is extremely useful industrially.However, for large-scale materials, especially for the full-scale joining of materials whose long side exceeds 50 cm, the joining surface The strain due to the difference in expansion between the metallic portion and the carbonaceous portion cannot be fully absorbed, and sometimes cracks and a peeling phenomenon at the joint surface may occur.

The present invention has been developed and improved for the purpose of compensating for the drawbacks that may occur in the above-mentioned prior application, particularly for the purpose of joining large-sized joint surfaces or materials used at relatively high temperatures. There is a big difference. That is, the basic aspect of the present invention is
[Carbon material-Cu-Fe-Mo-Fe-Cu-carbon material] or [Carbon material-Cu-Fe ^* -Mo-Fe-Cu-metal material] (However, in the case of metal material, omit the Fe ^* layer. It is also possible), and carbon material-Cu-F
The e-Mo part is an essential part of the configuration of the present invention, and this part is significantly different from the prior application.

The joined body joined by the method of the present invention or the method of the present invention is widely used in various fields. For example, the zygote may be a member of a fusion reactor, in particular the first wall or limiter, or an aircraft,
It is extremely useful as a material for rockets and space equipment. In addition, in the method of the present invention, the joining of the electrode copper and the graphite material or the joining of the carbon electrode and the copper conducting wire is carried out by attaching the water cooling mechanism of the electrode, the reflecting mirror, and the silicon carbide reflecting mirror, and the sliding of the submersible pump and the mechanical seal. It is also effectively used for dynamic surface adhesion.

〔effect〕

According to the present invention, even in a large-area joining operation, almost no cracking or peeling phenomenon occurs on the joining surface, and strong joining can be performed, and a new application aspect can be opened up.

〔Example〕

Hereinafter, embodiments of the present invention will be specifically illustrated by examples.

Example 1 (Example of joining graphite material and copper) The joining operation was performed in the following two steps.

(A) First, carbon material (isotropic graphite material made by Toyo Tanso: "IG-4
3 ") and the metal molybdenum plate as shown in FIG.
Bonded via a copper (acid-free copper) foil and an iron plate. However, these sizes are as follows.

Carbon material: 28 x 28 x 15 m / m, Fig. 3 (11) Copper foil: 0.1 m / m, Fig. 3 (12) Iron plate: 0.1 m / m, Fig. 3 (13) Molybdenum plate : 0.6m / m, (14) in Fig. 3 (14) After stacking the above, put about 500g of weight on top of the carbon material (11), heat up to 1200 ° C in nitrogen atmosphere and hold for 4 minutes. Gradually cooled.

(B) Next, place the sample obtained in (a) above on a copper plate (16) (30 x 30 x 25 m / m) through a gold braze as shown in Fig. 4, and place it in a nitrogen atmosphere at 950 Increase the temperature to ℃, hold for 4 minutes,
Gradually cooled.

After heating the joined body of the carbon material (11) and the copper plate (16) obtained by the above (a) and (b) to about 500 ° C, it was put into water and rapidly cooled, but peeling and cracking occurred. It was a strong joined body without cracks and the like.

The brazing filler metal used in the step (b) is an alloy having a composition of [Cu66 / Au34% by weight] and has a melting point of 950 to 990 ° C. Therefore, the melting point of pure copper (1040 ℃) is 50 ~
It can be joined without damaging the copper plate, which is the object to be joined, at a temperature 100 ° C lower. In this example, the joining process is (a),
The reason why the process is divided into two steps (b) is to take the above into consideration.

Example 2 As a carbon material (carbon / carbon) composite material [CX- manufactured by Toyo Tanso Co., Ltd.
2002 ”] was used to obtain a joined body under substantially the same conditions and operations as in Example 1.

However, in this example, carbon material: 28 × 28 × 15 m / m (CX-2002) to be joined Gold brazing foil: 0.1 m / m (Cu66%, Au34 wt%) Iron foil: 0.1 m / m molybdenum Foil: 0.6 m / m Gold brazing foil: 0.1 m / m (same as above) Copper: 28 × 28 × 25 m / m (material to be joined) without dividing the joining operation into two steps in order, 950 ℃ in nitrogen gas at once After heating up to 4 minutes and holding for 4 minutes, it was gradually cooled to complete the joining operation.

The obtained joined body was left at room temperature for about 1 month, but did not show any change in quality such as peeling, and when heated to 500 ° C and put in water, no phenomenon such as peeling or cracking was observed. .

Comparative Example 1 The joint obtained in Example 2 except that the Mo layer was treated in exactly the same manner was peeled and destroyed at the carbon-face-side joint surface when the joint was taken out at room temperature. This is (carbon / carbon)
The coefficient of thermal expansion (CTE) of the composite material "CX-2002" is 2 × 10 ^-6 /
This is because the CTE of copper is 17 × 10 ^-6 / ° C, and there is a marked difference between the two.

Example 3 In the same manner as in Example 2, stainless steel (200 × 50 × 1
A bonded body of 0 m / m, SUS316) and a (carbon / carbon) composite “CX-2002” was obtained.

However, in this example, since the metal side to be joined is stainless steel (about 1400 ° C) having a relatively high melting point, copper (acid-free copper) (melting point 10
80 ° C.) can be used.

Therefore, the order of the bonding material is as follows.

However, * 1 was an iron foil as it was, and * 2 was an iron foil which was previously coated with copper by electroplating.

The samples were stacked in the above order, a weight was placed from the top, the atmosphere in the furnace was set to a nitrogen atmosphere, the temperature was raised, the temperature was maintained at 1100 ° C. for 4 minutes, and then gradually cooled.

This example is a comparatively long material and is an example of joining between materials with a large CTE difference, and it has caused cracking, peeling and cracking phenomena in many experiments by the conventional method. According to the method of the invention, it was possible to carry out bonding without any peeling or cracking.

Example 4 Example 4 is a production example of a test member for evaluating whether or not the joined body obtained by the method described in Example 3 can be used as a material for a fusion reactor.

When used as a heat-resistant interior material in a furnace, especially for the first wall that requires the most strict heat-resistant properties, its strength properties at high temperatures, low outgas properties, and chemical erosion resistance properties due to Hz gas are required.

The carbon fiber / carbon matrix composite material (“CX-2002”: made by Toyo Tanso Co., Ltd.) is made to face the reaction atmosphere side, and the metal (stainless steel) side is made the back surface, and the carbon fiber / carbon matrix composite material is attached to the furnace body. The composite material itself has the above-mentioned characteristics and has been conventionally used for the first wall. Example 3
Since the joined body of No. 1 is formed by strongly joining a metal to this, it becomes easy to mount other members when used as the first wall, that is, the joined body obtained by the method of Example 3 has a back surface. Since it is a metal material, it is possible to freely and firmly attach a mounting vault or the like to the main body, and it is also possible to freely perform welding, drilling, etc. of the water cooling pipe on this metal. In addition, Example 7 is referred to for the method of mounting the water cooling pipe.

Example 5 The joined body obtained by the method described in Example 3 can be used as a member for aircraft.

That is, recently, due to its ultra-light weight and high strength properties, carbon fiber / carbon matrix composite materials are being used as space equipment and aircraft components, but the most technically problematic ones at present are This is a method of attaching this kind of composite material to the strength structure.

Fig. 5 (a) shows some examples of the places where aircraft are used, and (21) in the figure shows the outer tail plate (Out Bo).
ard Tail), (22) is the lavatory mogile section (Lavato
ry Module), (23) are inboard flaps (Inboard
Flap), and the joining method of the present invention can be effectively applied to the attachment of these members. An example of the mounting method is shown in Fig. 5 (b), which shows that the strength structural skeleton (3
When attaching the carbon fiber / carbon matrix composite material (32) to 1), a metal is used for the joining surface (33), and the method of the present invention is applied to this joining. Note that (34) indicates a mounting bolt.

Since the method of the present invention enables strong large-area joining, it can be applied to an aircraft requiring the highest safety for the first time.

Example 6 (Jointing Example of Electrode Copper and Graphite Material) The graphite material is used as an electrode for metal smelting (for example, aluminum) or electrolysis of hydrogen halide (for example, hydrogen chloride or hydrogen fluoride).

The main reason why the carbon material is used for this purpose is that the carbon material has high heat resistance, high corrosion resistance to chemicals, and high electric conductivity. However, the connectivity with a copper material, which is a wiring material, often becomes a problem.

Conventionally, carbon material and copper material are polished well on both sides,
A method of mechanically integrating with a vault, a nut, etc. is generally adopted, but there is a drawback that vapor and water drops of chemical substances penetrate into the mating surfaces due to continuous use and the contact resistance gradually increases.

By the method of the present invention, the joining area can be increased, and since the carbon material and the metal material are completely and firmly integrated, the connection resistance is small and the failure due to continuous use is small.

FIG. 6 shows an example of joining a carbon material (electrode) and a copper material (wiring wire).

In FIG. 6, (41) is a copper material (wiring), (42) is a copper bolt, and (43) is a flexible graphite sheet (Toyo Tanso "PE8").
0 ”) and (44) are graphite materials (graphite electrode,“ IG-1 ”manufactured by Toyo Tanso Co., Ltd.)
1 ”), and (45) are joint surfaces.

According to the form shown in FIG. 6, the graphite material (44) and the copper material (wiring) (41) were joined by the method of the second embodiment. A flexible graphite sheet (43) was interposed in order to accommodate expansion and contraction of the copper bolt (42).

Example 7 (Example of joining SiC and copper material) A reflecting mirror for short wavelength light (wavelength 100 nm or less) is
Particularly, heat resistance is required.

In this wavelength region, the theoretical reflectance is low, and unreflected light remains in the mirror body. Therefore, a material having high heat resistance (for example, silicon carbide) is used as the mirror body forming material. In order to avoid optical axis distortion due to temperature rise, a water cooling mechanism is provided on the surface opposite to the mirror surface. An example of this is shown in FIG. However, (51) in FIG. 7 is a material for a reflecting mirror, the inside is a carbon material, and the outside is a SiC coated surface. Further, (52) is a joint surface, and (53) is a cooling mechanism, which is entirely made of copper. (53
-1) shows a copper pipe for cooling water, and (53-2) shows a strain absorbing groove.

Bonding conditions: SiC material for reflector (SiC12 made by Toyo Tanso Co., Ltd. was used as the core material, and a silicon carbide layer was deposited on the surface by approximately 300μ CVD method) [100 × 50 × 15m / m] However, the intermediate layer was used Bonding was performed in the same order as in Example 1, and the two-step bonding method was used. The conditions for the copper material (140 × 50 × 50 m / m) oxygen-free copper bonding reaction are also the same as in Example 1.

Result: The bonded body was heated to about 700 ° C, put into water and rapidly cooled.
It was found to be very resistant to peeling, cracking, and thermal shock.

However, after cooling, we carefully examined the deviation of the optical axis on the reflecting surface,
Since a slight bowing change of the bonded body due to the difference in thermal expansion between the carbon material and the copper material was recognized, as shown in Fig. 7, the strain absorbing groove (53-2) was placed in the direction transverse to the long axis. When I set it up, I was able to prevent this.

[Brief description of drawings]

1 to 2 are schematic structural diagrams for explaining the method of the present invention, and FIGS. 3 to 4 are schematic structural diagrams for explaining the method of the present invention. FIG. 5 is an explanatory diagram when the method of the present invention is applied to a member of an aircraft, and FIG. 6 is a drawing for explaining an example of joining electrode copper and a graphite material. Further, FIG. 7 shows an explanatory view when a cooling device is joined to the reflecting mirror by the method of the present invention. 11 ... Carbon material, 41 ... Copper material (for wiring) 12 ... Copper foil, 42 ... Copper bolt 13 ... Iron plate, 43 ... Flexible graphite sheet 14 ... Molybdenum plate, 44 ... Graphite material (electrode) 15 ... Gold solder, 45 ... Bonding surface 16 ... Copper plate, 51 ... Reflector material 21 ... External tail plate, 51-1 ... Carbon material 22 ... Lavatory module, 51-2 ... SiC coating layer 23 ... Inboard flap, 52 ... Bonding surface 31 … Strength structural skeleton material, 53… Cooling mechanism 32… Composite material, 53-1… Copper tube 33… Joint surface, 53-2… Groove 34… Bolt

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Teruhisa Kondo, 5-7-12 Takeshima, Nishiyodogawa-ku, Osaka City, Osaka Prefecture Examiner Masahiro Hiratsuka, Toyo Carbon Co., Ltd. (56) Reference JP-A-1-290567 (JP, A)

Claims (14)

[Claims] 1. In the joining of (A) a carbon material containing 0.2% by weight or more of carbon, and (B) a metal or the above carbon material (excluding joining of carbon steels), (C) linear expansion A metal or (and) a metal alloy having a coefficient of 7 × 10 ⁻⁶ / ° C. or less is used as an insert material, and (D) a carbon material (A) and an insert material (C) are provided with iron or an iron alloy, ( E) A method for joining carbonaceous materials, characterized in that copper or copper alloy containing at least 25% by weight of copper is used as a joining material for joining. 2. The joining method according to claim 1, wherein at least one surface of the metal or (and) metal alloy (C) having a linear expansion coefficient of 7 × 10 ⁻⁶ / ° C. or less is iron or iron alloy ( E)
A joining method, characterized in that a preformed layer is used. 3. The joining method according to claim 1,
A joining method comprising using iron or an iron alloy (D) and a copper or copper alloy layer (E) further containing copper in an amount of at least 25% by weight in advance. 4. The metal or (and) metal alloy (C) having a thermal expansion coefficient of 7 × 10 ⁻⁶ / ° C. or less according to at least one of claims (1) to (3) is molybdenum. Joining method characterized by. 5. At least 25% copper as claimed in claim 1.
A method for joining carbon materials, characterized in that the copper or copper alloy (E) containing more than one weight is a gold solder and / or a silver solder. 6. The carbon material (A) or (B) according to claim 1, wherein the carbon content (A) or (B) contains 0.2% by weight or more of carbon, includes an isotropic carbon material, an anisotropic carbon material and free carbon. At least one of carbon fiber-carbon matrix composite material such as metal carbide, cemented carbide, and cermet, composite material in which carbon is mixed or impregnated with metal, and composite material in which carbon is mixed with ceramic
A joining method characterized by being a seed. 7. The metal (B) according to claim 1 is copper,
Tungsten, molybdenum, iron, silicon, stainless steel,
A joining method comprising at least one of Hastelloy, Inconel, various alloy steels and iron alloys. 8. A joined body joined by the joining method according to claim 1. 9. A fusion reactor using the joined body according to claim 8 as an internal heat-resistant member. 10. An aircraft using the joined body according to claim 8 as at least a part of its members. 11. A member for an electrode, wherein the joined body according to claim 8 is used as at least a part of the member. 12. A reflecting mirror body using the joined body according to claim 8 as at least a part thereof. 13. A reflecting mirror body using the bonded body according to claim 8 on two side surfaces. 14. A pump using the joined body according to claim 8 as a sliding member for a liquid sealing portion.