JP2008120626A - Joined body and joining method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a joined body of a base material, such as a ceramic material, and a carbon material; and to provide a method for joining the same. <P>SOLUTION: The joined body has such a structure that a carbon material 1 and a carbide-based ceramic material 2 having, as one of constitutive elements, carbon on the surface to be joined with the carbon material 1 are joined by inducing a chemical reaction which produces the same compound as the carbide-based ceramic material 2. The joining process comprises depositing a film composed of constituting elements 3 except carbon of the carbide-based ceramic material 2, being an intermediate material, on at least one of the joining surface 1a of the carbon material 1 and the joining surface 2a of the carbide-based ceramic material 2, then stacking the carbon material 1 and the carbide-based ceramic material 2, setting the stacked carbon material 1 and carbide-based ceramic material 2 in a chamber 6 of a joining apparatus 5, further reducing the pressure at the inside of the chamber 6, applying pressure to the joining face between the stacked carbon material 1 and carbide-based ceramic material 2, and joining the stacked carbon material 1 and carbide-based ceramic material 2 by raising the temperature of the chamber 6. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a joined body used for an optical element such as an optical glass lens, a resin lens, and a prism, a mold for a glass magnetic disk substrate, and the like.

  The use of glassy carbon as a glass mold material is known (Patent Document 1). In the case of glass optical elements, it is not rare that the molding temperature exceeds 600 ° C, and glassy carbon is the molding material because it is difficult to cause high-temperature deterioration of the mold due to high temperature and fusion between the glass and the molded part. It is effective as

  In order to configure a glass mold used for molding an optical element with glassy carbon, it is advantageous that the glass mold has a certain physical size. This is because when the shape of the molding surface is changed, it can be easily done by additional machining. However, glassy carbon suitable for glass molding is only industrially produced in the form of a plate-like material having a thickness of 10 mm or less. Therefore, although it has long been known that glassy carbon has merits for use in glass molding, such as heat resistance, low reactivity with glass materials, and good releasability. It was not used industrially.

  Currently, glass mold materials used industrially are made of carbide or ceramics as a base material in terms of heat resistance and strength, and platinum-based alloy films or DLC (diamond-like) are used on the molding surface in contact with glass. Carbon), a carbon-based thin film is formed. However, even if a material having excellent heat resistance and strength is used as the base material of the mold, there is a problem that the life of the mold is short because the thin film on the molding surface in contact with the glass is peeled off.

Therefore, returning to the original (Patent Document 2) to (Patent Document 5), attempts have been made to use glassy carbon of a bulk material as a mold.
In (Patent Document 2), the idea is to join a base material made of a carbon-based material and glassy carbon to be a molding surface using a carbon-based adhesive. The thermal expansion coefficients of the base material, the adhesive, and the glassy carbon are relatively close, and the generation of stress due to heat is considered to be relatively small.

(Patent Document 3) (Patent Document 4) proposes brazing glassy carbon and a substrate.
In Patent Document 5, there is an example in which an intermediate material is provided on a SiC base material and bonded by a hot press method to form a glass mold.

In such a configuration, the functions can be divided between the base material and the molding material, and a higher performance molding die can be configured. The base material and the molding material can be integrally formed so that the joint portion between the base material and the molding material is continuously changed.
JP 47-11277 A Japanese Patent No. 2626880 JP-A-6-340435 JP 2005-112672 A JP 2001-335334 A

  However, as in (Patent Document 2), there is a problem in terms of mold configuration to bond a carbon material serving as a base material and glassy carbon with a carbon-based adhesive. For one thing, the strength of the substrate is too weak, which causes practical problems. Secondly, the bonding strength between the carbon-based adhesive and the glassy carbon is weak and not practically used.

  Next, it is technically difficult to braze the glassy carbon and the base metal as in (Patent Document 3). First of all, glassy carbon has low wettability, and the brazing material does not have bonding strength as it is.

In the method of (Patent Document 4), the bonding is possible and the bonding strength is sufficient, but if the bonding area is increased, the thermal stress may be increased and may be broken. This is because the thermal expansion coefficient of silicon carbide and glassy carbon as the base material is as small as 3-4 × 10 ⁻⁶ / ° C. and almost equal, whereas the thermal expansion coefficient of the brazing material is 18 × 10 ^−6. This is due to the large combination of / ° C.
When such a joined body is used for a glass mold, it can be easily inferred that thermal fatigue failure is caused by repeating molding cycles of temperature increase and temperature decrease. In particular, at the interface between the SiC and the brazing material, the stress generated due to the high Young's modulus of SiC is increased, and there is a high possibility of thermal fatigue failure at this interface.

  Next, the structure which joins a SiC base material and glassy carbon by a hot press method is not practical because the process of making a composite is too complicated. Since the intermediate material formed for the purpose of joining the base material and the functional material serving as the forming part is composed of multiple elements, it is necessary to form an expensive film forming apparatus under complicated control. And since the thickness of an intermediate material is as thick as 1 micron or more, it has the subject that time is required in implementation.

  Even if SiC and glassy carbon serving as a base material are made integrally, the firing conditions for SiC and glassy carbon are different, and even if they are made simultaneously, the respective functions are not sufficiently satisfied.

  The present invention solves the above-described conventional problems, and provides a practical joined body and a joining method thereof that can easily form a joined body of glassy carbon and a substrate such as silicon carbide as compared with the conventional art. For the purpose.

  According to a first aspect of the present invention, there is provided a bonded body comprising: a carbon-based ceramic material having carbon as one of constituent elements on a bonding surface between a carbon material and the carbon material; and a chemistry that generates the same compound as the carbide-based ceramic material. It is characterized by joining by inducing a reaction. According to this configuration, since the joined body is made of a material having substantially the same thermal expansion coefficient, distortion due to thermal stress is unlikely to occur, and separation of the joint surface is difficult to occur.

  In the joining method according to claim 2 of the present invention, when the carbon material and a carbide ceramic material having carbon as one of the constituent elements are laminated and joined to the joining surface of the carbon material and the carbon material, the carbon material and the carbide are bonded. A step of laminating a layer made of a constituent element other than carbon of the carbide-based ceramic material between the ceramic-based ceramic material, and setting the laminated carbon material and the carbide-based ceramic material in a chamber of a bonding apparatus, A step of evacuating the interior of the chamber, a step of applying pressure to the bonding surface of the laminated carbon material and the carbide-based ceramic material, and heating the chamber of the bonding apparatus to raise the temperature other than the carbon of the carbide-based ceramic material. And a step of inducing atomic diffusion between the layer made of the constituent elements and the carbide-based ceramic material. According to this structure, it can join easily and firmly.

  The bonding method according to claim 3 of the present invention is the bonding method according to claim 2, wherein a layer made of a constituent element other than carbon of the carbide ceramic material is sandwiched between the carbon material and the carbide ceramic material. Is characterized in that a layer made of a constituent element other than carbon of the carbide ceramic material is deposited on at least one of the bonding surfaces of the carbon material or the carbide ceramic material and then laminated. According to this configuration, constituent elements other than carbon of the carbide-based ceramic material can be easily sandwiched between the carbon material and the carbide-based ceramic material.

  The bonding method according to claim 4 of the present invention is characterized in that, in claim 2, the carbon material is glassy carbon, diamond, graphite or fullerene crystal.

  The bonding method according to claim 5 of the present invention is characterized in that, in claim 2, the carbide-based ceramic material is silicon carbide or boron carbide. According to this configuration, the constituent elements other than carbon of the carbide-based ceramic material serving as the intermediate material act effectively, and the carbon material and the carbide-based ceramic material of the base material can be firmly bonded.

  The bonding method according to claim 6 of the present invention is characterized in that, in claim 3, the thickness of the layer made of a constituent element other than carbon of the carbide-based ceramic material is 1 micrometer or less. According to this structure, constituent elements other than carbon of the carbide-based ceramic material and the carbon material react satisfactorily, and stronger bonding is possible.

The joining method according to claim 7 of the present invention is the joining method according to claim 2, wherein the degree of vacuum reached is at least 1 × 10 ⁻¹ Pa or more, the pressure applied to the joining surface is at least 5 MPa, and the joining temperature is 800 ° C. or more. It is characterized by that. According to this configuration, a strong bonded body can be configured.

  The forming die according to claim 8 of the present invention is characterized in that a forming surface is formed on the surface of the bonded body according to claim 1 which is not the bonding surface between the carbon material and the carbide-based ceramic material. According to this configuration, the mold is repeatedly heated / cooled each time it is molded, but a mold structure without thermal fatigue failure can be configured.

  Thus, it is possible to easily form a joined body of a carbon material and a carbide-based ceramic material base material as compared with the conventional one, and to produce a molding die for an optical element having the carbon material side of the produced joined body as a molding surface. It becomes possible. Further, according to the mold, even if the high temperature at the time of molding and the room temperature at the time of taking out are repeated, the stress generated at the joint is small, and it is practical because it can withstand thermal fatigue. Moreover, since it becomes possible to use carbon materials, such as glass-like carbon which can be obtained practically, for a molding part, it is excellent also in terms of durability at high temperatures and releasability.

Hereinafter, the joining method of the present invention will be described based on specific embodiments.
FIG. 1 is a manufacturing process flow of a joined body according to the joining method of the present invention.
Reference numeral 1 denotes glassy carbon as a carbon material. Reference numeral 2 denotes a ceramic as a base material, specifically silicon carbide as a carbide-based ceramic. It is effective at the time of bonding if the bonding surface 1a of the glassy carbon 1 and the bonding surface 2a of the ceramic 2 are polished smoothly in advance. Although it is drawn like a plane in the figure, it may be a curved surface.

  After smooth polishing, a silicon film 3 as a layer made of a constituent element other than carbon of silicon carbide as the ceramic 2 is formed on the bonding surface 2a of the silicon carbide 2 by a thin film process. The effective thickness of the silicon film 3 is 1 micrometer or less. The film forming method may be sputtering or vapor deposition.

  After the film formation, the bonding surface 2a with the bonding surface 1a is put into the bonding device 5 so as to be in contact with the silicon film 3 therebetween. The bonding apparatus 5 needs to have a function of evacuating the chamber, a function of pressurizing the sample, and a function of heating. In the actual bonding process, after the sample is put, the inside of the chamber of the bonding apparatus 5 is evacuated to a predetermined pressure.

  Thereafter, the sample is heated. It is desirable that the heating start timing is after the degree of vacuum reaches a predetermined value. This is because when the glassy carbon 1 is heated in an oxygen atmosphere, it reacts with oxygen to generate carbon monoxide and carbon dioxide. In general, the reaction with oxygen occurs at temperatures above about 400 ° C. Since the meaning of making a vacuum is the discharge of oxygen, if oxygen substitution is performed, bonding may be possible even in an inert gas atmosphere such as nitrogen or argon.

  Next, after reaching a predetermined temperature, the glassy carbon 1 and the ceramics 2 are pressurized from above and below to apply pressure to the bonding surfaces 1a and 2a and hold for a certain time. By applying pressure at a high temperature, silicon carbide is formed by an interfacial reaction between the silicon film 3 and the glassy carbon 1. That is, the layer of the silicon film 3 of the intermediate material is almost lost after the bonding is completed. Further, by applying pressure at a high temperature, the silicon film 3 reacts with carbon to partially form silicon carbide, so that the silicon carbide portion changes in the stacking direction from the bonding surface 2a and becomes silicon carbide. A mixed layer 4 in which carbon and carbon are mixed is formed.

After pressurization at this high temperature, the sample is cooled to room temperature, opened to the atmosphere, and the sample is taken out from the bonding apparatus 5.
The general process described above will be described in detail for each process.

  FIG. 2 shows the size of the sample used in the process of the present invention. Here, CG23 (Tokai Carbon Co., Ltd., trade name) having a thickness of 3 mm was used as the glassy carbon 1. As ceramic 2, silicon carbide SC1000 (Kyocera Corporation, trade name) having a thickness of 4 mm was used.

  The joining surface 1a of the glassy carbon 1 and the joining surface 2a of the ceramic 2 were processed by lapping. Both joining surfaces 1a and 2a were processed with a tin lapping machine using diamond slurry having an average particle diameter of 2 microns. 3 (a) and 3 (b) are enlarged views of the bonded surface after smooth polishing.

  The bonding surface 1a of the glassy carbon 1 was a surface having a maximum height of 29 nanometers. The joining surface 2a of the ceramics 2 applied under the same processing conditions has a maximum height of 54 nanometers. It can be seen that the bonding surface 2a is a partially recessed working surface because pores existing inside the material appear.

  Although it is unclear how much the joint surface needs to be smooth in carrying out the bonding of the present invention, in view of the mechanism of the present invention, the smoother surface has a substantial bonding area. It is expected to increase and be effective. In other words, if the roughness of the surfaces to be joined increases, the substantially contacted part can be joined, but the partially unjoined part increases, so that it may not reach the predetermined joint strength as a whole. It is done.

  Next, a silicon film 3 is formed on the bonding surface 2 a of the ceramic 2. In this process, silicon was formed by sputtering. The thickness of the silicon film 3 is sufficient to be 1 micrometer or less. Since this silicon film 3 reacts with carbon to form silicon carbide after bonding, it is considered that if it is thicker than necessary, reaction time is required and bonding becomes insufficient.

The theoretical examination of the joining will be described with reference to FIGS. 9 (a) to 9 (d).
When a carbon material (for example, glassy carbon) and a carbide-based ceramic material (for example, silicon carbide) are brought into close contact with each other through a silicon thin film in a vacuum and the temperature is raised moderately, diffusion of constituent atoms of each material becomes active. It comes to occur. However, since the bond energy between atoms (= atomic binding force: index of difficulty of movement) varies greatly depending on the material, the moving speed of atoms due to diffusion varies greatly depending on the material. Carbon and silicon in silicon carbide are very strongly covalently bonded and chemically stabilized, whereas silicon is significantly activated by raising the temperature, and atomic diffusion (self-diffusion and (Phenomenon called) becomes active. Further, it is known that both the solubility of carbon in silicon and the solubility of silicon in silicon carbide are extremely insignificant. Therefore, it is considered that almost no diffusion and dissolution of carbon into silicon and silicon into silicon carbide occurs. From the above, it can be seen that the atomic migration occurring at the bonding interface is mostly atomic diffusion from the silicon thin film to the glassy carbon.

  The silicon atoms diffused into the glassy carbon immediately form a strong covalent bond with the carbon atoms of the glassy carbon to form silicon carbide. In the region where silicon carbide is formed, subsequent atomic movement is significantly restricted. For this reason, silicon atoms reach the unreacted region of the glassy carbon by diffusing the surface of the unbonded portion (the region serving as a void) at the bonding interface, and react. In this way, the diffusion of silicon atoms in the direction perpendicular to the bonding interface is mainly performed at the very early stage of bonding, but this gradually reduces the velocity, along the unbonded portion of the interface (parallel to the interface). Atomic diffusion (in any direction) occurs predominantly.

  Glassy carbon, silicon thin film, and silicon carbide are all brittle materials that can hardly be expected to undergo plastic deformation compared to metal materials, so even if the joint surface is smooth, the area actually in contact at the initial stage is It can be seen that there is very little (FIG. 9A). The atomic diffusion in the direction parallel to the interface at the time of bonding can be regarded as such a flow of atoms toward the unbonded portion (= void). By this mechanism, the substantial bonding area is expanded by filling the gap (FIGS. 9B to 9C). Finally, the silicon thin film completely reacts with glassy carbon to become silicon carbide, and a bonding interface in which a very large gap remains is formed (FIG. 9D). The process from FIG. 9 (a) to FIG. 9 (c) proceeds at a very high speed, but the process from FIG. 9 (c) to FIG. 9 (d) takes a considerable amount of time.

FIG. 4 shows a schematic view of the bonding apparatus 5 used in the present invention.
Although the present invention can be realized without necessarily having the same configuration as that of FIG. 4, a joining apparatus used as an example will be described.

  The bonding apparatus 5 includes a chamber 6 and a vacuum pump 7 which is not described in detail in this drawing, and for making the inside of the chamber 6 have a predetermined degree of vacuum. The chamber 6 is provided with a heating device 8 for heating the sample and a hydraulic cylinder 9 for applying pressure.

  The heating device 8 induction-heats the carbon heating body 11 with the induction coil 10. A thermocouple 12 is provided in the heating body 11 and is configured to be fed back to a controller (not shown) for controlling the induction coil for temperature control. The configuration is such that the sample is placed inside the heating element 11. Further, since the heating temperature is high, a heat insulating material 13 is provided to protect the induction coil 10.

The heating device 8 operates as follows.
When control is performed based on a predetermined temperature profile, a current flows through the induction coil 10 and the heating element 11 is heated. As a result, the sample (glassy carbon 1, ceramics 2 and silicon film 3 not shown) provided further inside the heating body 11 is heated by radiation. The temperature can be controlled by measuring the temperature of the heating element 11 with the thermocouple 12.

  The pressurizing mechanism for applying pressure to the joining surfaces 1a and 2a is located above and below so as to sandwich the sample. In the case of this experimental apparatus, pressurization is performed by the hydraulic cylinder 9. The upper and lower sides of the sample are pressurized through a carbon pressing jig 14. The pressing jig 14 is preferably a carbon jig so that the pressing jig 14 is not bonded even if it is in strong contact with the sample at a high temperature.

Further, in order to measure the temperature in the vicinity of the sample, a hole is formed in the center of the press jig 14, and a thermocouple 15 is provided so that the temperature immediately below the sample can be measured.
FIG. 5 shows a conceptual diagram of a process flow by the joining apparatus of FIG. 4 as an example of the joining process of the present invention.

  First, the glassy carbon 1 and the ceramic 2 are put in the bonding apparatus 5 so that the bonding surfaces are in contact with each other through the silicon film 3. The reason why the sample pressing force is slightly higher as indicated by P1 in the figure is to prevent the sample from moving.

Next, the degree of vacuum in the chamber 6 is increased. When the degree of vacuum is approximately 1 × 10 ⁻¹ Pa or higher, heating is performed. In the experimental apparatus of FIG. 4, the temperature display value of the thermocouple 12 and that of the thermocouple 15 do not show the same value as shown in FIG. The thermocouple 12 shows a higher value than the thermocouple 15 at a certain rate. The two temperatures can be expected to vary depending on the configuration of the bonding apparatus 5 and the measurement site.

  Here, the experiment was performed based on the temperature display value of the thermocouple 12 that can be easily controlled. Although it differs depending on the set temperature, the value of the thermocouple 15 is lower by 100 to 150 ° C. than the display value of the thermocouple 12.

When the temperature reaches a predetermined value, pressurization is performed so that the set pressure is reached. Hold in that state for a certain period of time.
Thereafter, the heating is stopped. Here, natural cooling was performed while maintaining the pressure. When the temperature measurement unit reached 200 ° C. or lower, the degree of vacuum was reduced to atmospheric pressure, and the pressure on the sample was released.

A joining test was performed under the conditions shown in Table 1 below. Each experimental condition in the table is as follows, taking Condition 1 as an example. Silicon carbide having a diameter of 6 mm and glassy carbon (GC) are controlled so that the heating element 11 is 1300 ° C. in an atmosphere having a degree of vacuum of 1 × 10 ⁻³ Pa, and the stress of the bonding surface (φ6) becomes 50 MPa. Pressurize as follows. It means that an experiment was conducted by depositing silicon (Si) on the bonding surface to a thickness of 50 nm on the silicon carbide (SiC) substrate side.

（表１）中の条件２、条件３の接合時の加熱体１１の実験温度が１１００℃の条件を除き、強固に接合できた。珪素（Ｓｉ）の成膜は、条件１０，条件１１の通りガラス状カーボン側に施しても同様の効果があることが確認できた。また同表中の条件１２に示す通り接合面に珪素が無いと、全く接合できないことが確認できた。

Except for the condition that the experimental temperature of the heating element 11 at the time of joining in the conditions 2 and 3 in (Table 1) was 1100 ° C., it was possible to join firmly. It was confirmed that the silicon (Si) film had the same effect even when applied to the glassy carbon side as in conditions 10 and 11. Further, as shown in the condition 12 in the same table, it was confirmed that the bonding could not be performed at all if there was no silicon on the bonding surface.

  FIG. 6 shows an enlarged view of the SEM (scanning electron microscope) of the joint surface under the condition 1 in (Table 1). FIG. 6A shows a state in which the bonded surface after bonding is processed by FIB (Focused Ion Beam) to clarify the interface, and FIG. 6B is surrounded by a square in FIG. 6A. The interface of the area is processed with FIB in the depth direction and is seen from the direction of arrow A. The magnification of FIG. 6 (a) is 3000 times, and the magnification of FIG. 6 (b) is 7500 times.

  From FIG. 6A, a portion having a different contrast is observed over a region having a width of about 2 micrometers on the bonding surface, and this is considered to be a mixed layer 4 in which silicon carbide and carbon are mixed. That is, in the case of the sample of the condition 1, it is expected that the silicon film 3 of 50 nanometers was formed on the surface of the ceramic (silicon carbide) 2 and thus reacted with the carbon of the glassy carbon 1.

  In FIG. 6B, the presence of the mixed layer 4 was confirmed even when observed in the depth direction. The position indicated by the arrow B is the position of the bonding surface between the bonding surface 1 a of the glassy carbon 1 and the bonding surface 2 a of the ceramic 2.

FIG. 7 shows the result of elemental analysis of each part shown in the enlarged microscopic view of FIG.
A point X in FIG. 7 is a silicon carbide portion of the ceramic 2. The element ratio in silicon carbide is 50:50 for silicon and carbon. However, in this measurement, although the ratio of silicon appears to be higher than that of carbon, it is because the detection sensitivity of carbon, which is a light element, is low. Although gallium is detected, it is because it was processed by FIB, and is an element that is not originally present. Some oxygen is also detected, but details are unknown. The presence of gallium and oxygen is common to points X, Y, and Z.

  Point Y is a glassy carbon part. The main component is carbon. Point Z is the mixed layer 4. Originally, the silicon film 3 of 50 nanometers is considered to have reacted depending on the bonding conditions. Considering from the result of the composition analysis, carbon has a low peak of detection sensitivity, so carbon is considered to be the main component. However, since the peak of silicon is clear, it is considered that silicon carbide is partially generated. The abundance ratio of silicon carbide is a mixed layer that decreases from the ceramic 2 side toward the glassy carbon 1 side.

  In the above specific example, the silicon film 3 is formed on the bonding surface 2a of the silicon carbide 2 out of the bonding surface 1a of the glassy carbon 1 and the bonding surface 2a of the ceramic 2, but the bonding surface of the glassy carbon 1 The silicon film 3 may be formed on the thin film process 1a. The effective thickness of the silicon film 3 is 1 micrometer or less. The film forming method may be sputtering or vapor deposition. Alternatively, the silicon film 3 is formed on the bonding surface 1a of the glassy carbon 1 and the bonding surface 2a of the silicon carbide 2 by a thin film process, sputtering or vapor deposition, respectively.

In addition, as for each film thickness in this case, it is effective that the total value of both films is 1 micrometer or less.
In the experimental example shown in Table 1, the degree of vacuum was 1 × 10 ⁻³ Pa, the pressure applied to the joining surface was 50 to 65 MPa, and the joining temperature was 1100 to 1450 ° C., but the degree of vacuum was at least 1 ×. Good results were obtained when 10 ⁻¹ Pa or higher, the pressure applied to the bonding surface was at least 5 MPa, and the bonding temperature was 800 ° C. or higher.

  The joined body created in this way is formed, for example, by forming a molding recess (molding surface) 16 on the surface 1b opposite to the joining surface 1a of the glassy carbon 1 as shown in FIG. It can be used for optical elements such as optical glass lenses, resin lenses, and prisms, and glass magnetic disk substrate molds.

FIG. 8 shows an example of a glass lens molding machine using the joined body of the present invention.
The upper punch 17 and the lower punch 18 have a pair of structures, and are composed of the joined body according to the present invention. That is, the molding recess (molding surface) 16 of the lens 19 is formed on the surface 1 b of the glassy carbon 1.

  In the example of FIG. 8, the upper punch 17 and the lower punch 18 are inserted so as to be along the body mold 20 whose inner diameter is processed with high accuracy. And in the state which put the lens raw material in the glassy carbon mold which becomes the forming surface, in this example, the temperature is raised by the induction heating unit 21, and when the predetermined temperature is reached, the pressure shaft 22 is controlled, The upper punch 17 and the lower punch 18 are pressed between the base 23 and the mold shape is transferred to the lens surface.

  In each of the above embodiments, the case of joining glassy carbon and silicon carbide has been described as an example, but the present invention can be applied to joining various carbon materials and carbide-based ceramic materials. As a carbon material, in addition to glassy carbon, diamond, graphite, fullerene crystal, and a carbide-based ceramic material can be applied to a combination of boron carbide in addition to silicon carbide. When boron carbide is selected as the carbide-based ceramic material, an intermediate layer is formed in the step of laminating a layer made of a constituent element other than carbon of the carbide-based ceramic material between the carbon material and the carbide-based ceramic material. Bonding can be performed in the same manner by laminating boron (boron).

  The joined body of the present invention, its manufacturing method, and a mold using the joined body can provide a highly reliable mold that does not peel even in a use environment in which the temperature is raised and lowered. Therefore, the present invention is not limited to glass lens and resin lens molds, and can be widely applied as a glass hard disk manufacturing apparatus or a communication optical device manufacturing apparatus.

Process flow diagram of composite and manufacturing method thereof in an embodiment of the present invention Diagram of an example of a sample in an embodiment of the present invention The figure of the pre-processing state of the joint surface in embodiment of this invention The figure of the joining apparatus in embodiment of this invention Conceptual diagram of bonding process in an embodiment of the present invention The figure of the joint surface of the joined body in embodiment of this invention The figure of the component analysis example of the conjugate | zygote in embodiment of this invention The figure of the glass molding die using the joined object in an embodiment of the invention Theoretical illustration of the joining process of the present invention

Explanation of symbols

1 Glassy carbon 2 Ceramics (silicon carbide)
3 Silicon film (intermediate material)
4 Mixing Layer 7 Vacuum Pump 9 Hydraulic Cylinder 10 Induction Coil 11 Heating Body 12 Thermocouple 13 Heat Insulating Material 14 Pressing Jig 15 Thermocouple 17 Upper Punch 18 Lower Punch 19 Lens 20 Body Mold 21 Induction Heating Unit 22 Pressure Shaft 23 Base

Claims (8)

A joined body in which a carbide ceramic material having carbon as one of constituent elements is joined to a joining surface between a carbon material and the carbon material by inducing a chemical reaction that generates the same compound as the carbide ceramic material. When laminating and bonding a carbonaceous ceramic material having carbon as one of the constituent elements on the bonding surface between the carbon material and the carbon material,
A step of laminating a layer made of a constituent element other than carbon of the carbide ceramic material between the carbon material and the carbide ceramic material;
Setting the laminated carbon material and the carbide-based ceramic material in a chamber of a bonding apparatus and evacuating the inside of the chamber; and
Applying a pressure to the bonding surface of the laminated carbon material and the carbide-based ceramic material;
A bonding method including a step of inducing atomic diffusion between a layer made of a constituent element other than carbon of the carbide-based ceramic material by heating the chamber of the bonding apparatus and the carbide-based ceramic material. A step of laminating a layer made of a constituent element other than carbon of the carbide ceramic material between the carbon material and the carbide ceramic material,
3. The bonding according to claim 2, wherein a layer made of a constituent element other than carbon of the carbide-based ceramic material is formed on at least one of the bonding surfaces of the carbon material or the carbide-based ceramic material, and then laminated. Method. 3. The joining method according to claim 2, wherein the carbon material is glassy carbon, diamond, graphite, or fullerene crystal. The joining method according to claim 2, wherein the carbide-based ceramic material is silicon carbide or boron carbide. 4. The bonding method according to claim 3, wherein the thickness of the layer made of a constituent element other than carbon of the carbide-based ceramic material is 1 micrometer or less. The joining method according to claim 2, wherein the degree of vacuum reached is at least 1 × 10 ⁻¹ Pa, the pressure applied to the joining surface is at least 5 MPa, and the joining temperature is 800 ° C. or more. The shaping | molding die which formed the shaping | molding surface in the surface which is not a joining surface with the said carbide | carbonized_material ceramic material of the said carbon material of the joined body of Claim 1.

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