JPS59102880A - High temperature heat resistant material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to high-temperature heat-resistant materials, and more particularly, to heat-resistant materials suitable for various high-temperature heat treatment furnaces, high-temperature heating walls, heat insulating materials, and the like.

Composite materials made of carbon materials (hereinafter referred to as carbon materials) and ceramic materials are used for a variety of purposes because of their excellent chemical properties including heat resistance and chemical resistance, and thermal insulation properties. has been done. However, the above-mentioned conventional composite materials have the drawback that when used at high temperatures, especially at temperatures close to the softening point of the ceramics that make up the composite material, they tend to crack or wear out significantly, making it impossible to use them for long periods of time. was there.

For example, FIG. 1 is a schematic cross-sectional view showing an example of an apparatus for pulling silicon single crystals, and this apparatus uses a crucible made of a graphite container lined with quartz. That is,
In Fig. 1, 1 is a crucible, 2 is a silicon melt filled in the crucible 1, 3 is a silicon crystal immersed in the silicon melt 2, 4 is a heater, 5 is a heat insulating wall, and 6 is a bimeter. , 7 is a heat treatment chamber for accommodating the above-mentioned metal 1, heater 4, heat insulating wall 5, etc., and maintaining it at a predetermined temperature; 8 is a gas inlet;
9 is a gas outlet. In Fig. 1, this device fills a crucible 1 with a silicon melt 2, immerses a silicon crystal in the silicon melt 2, and immerses the silicon crystal in nitrogen, argon, and cum, which is kept at about 1500°C. The silicon melt 2 is maintained in an inert gas atmosphere to grow crystals in the silicon melt 2.However, in such an apparatus, due to the difference in the thermal film 111 between the graphite and quartz that make up the crucible, when the temperature rises or Cracks tend to form in the crucible during cooling.In particular, recently there has been a strong demand for single crystals with large diameters, but in order to produce such single crystals, it is necessary to use a crucible with a large internal volume.
In that case, damage to the crucible increases the cost of producing single crystals, since crucibles are expensive. In addition, handling and operability during manufacturing are significantly reduced. Furthermore, in the production of the silicon single crystal,
The silicon melt that fills the crucible reaches a high temperature of approximately 1400°C or higher, and at such high temperatures, a certain chemical reaction occurs at the interface between the quartz and graphite that make up the crucible. There is also the possibility that crucible wear and tear may occur.

For example, 5t02, which is a chemical constituent of quartz, reacts as shown in the following formula at high temperature (approximately 1400° C.).

2Si02-Yu2SiO+02 S i O+ 2 C-1 → S i C+ 002 C
+02 -1→2GO 8iO2,03G, -+SiC,2GO The present inventor arrived at the present invention as a result of studying a high-temperature heat-resistant monthly rate that does not have the above-mentioned drawbacks.

That is, an object of the present invention is to provide a high-temperature heat-resistant material that solves the above-mentioned drawbacks of composite materials made of carbon materials and ceramic materials and used in various applications such as heat-resistant containers such as crucibles and high-temperature heat treatment furnaces. There is something to do.

The above-mentioned object of the present invention is to provide a high-temperature heat-resistant material comprising a laminated structure in which a carbon fiber-reinforced carbon material (hereinafter referred to as C-C composite) layer is interposed between a carbon material layer and a ceramic layer. This is achieved by

Hereinafter, the present invention will be explained in detail based on the drawings.

FIG. 2 is a schematic cross-sectional view showing an embodiment of the high temperature heat resistant material according to the present invention in a crucible, in which 1O is a ceramic layer, 11 is a C-(consolidated layer), and 12 is a carbon material layer.

As shown in FIG. 2, the heat-resistant material of the present invention is characterized in that a C--C composite layer 11 is interposed between a ceramic layer 10 and a carbon material layer 12.

In the present invention, ceramics, C-C composite J
3 and the carbon material may be in a simply laminated state (although it is preferable that they are integrally bonded).

Here, known ceramics and carbon materials are used as constituent materials of the heat-resistant material of the present invention.

For example, ceramics include alumina, silica (
Oxide ceramics such as quartz), zirconia, and titania, nitride ceramics such as silicon nitride and titanium nitride, and carbide ceramics such as silicon carbide, butane carbide, and zirconium carbide can be used. These ceramics are appropriately selected and used depending on the use of the heat-resistant material of the present invention.

Further, as the carbon material, the same material as the matrix carbon constituting the C--C composite is used, but graphitic carbon is preferable.

Further, the C-CD composite layer sandwiched between the ceramic layer and the carbon material layer is made of carbon fibers as reinforcing fibers, and these carbon fibers are bonded and integrated with 71-RiX carbon. Although it depends on the type, content, orientation state, etc. of carbon fibers, carbon fibers with a bending strength of at least 10 kg/l11 m2 are preferably used.

As the matrix carbon constituting this C--C composite layer, soft carbon, hard carbon, pyrolytic carbon, etc. are used. Examples of soft carbon include heavy petroleum oil, pitch, which carbonizes through the liquid phase.
Examples of hard carbon include polycyclic aromatic compounds such as an-1-herasene, and carbides of vinyl chloride resin. Examples of hard carbon include carbides of thermosetting resins such as phenol, furan, and acrylic resins, which are carbonized in the same phase. In addition, pyrolytic carbon is produced by bringing hydrocarbon gas such as methane, propane, bempine, acetylene, etc. into contact with a base material heated to 700 to 2000°C in a hydrogen stream, and depositing it on the surface of the base material. It is something.

Which of these 71-lix carbons to use is determined by taking into consideration the characteristics of the carbon, depending on the type of Reramix layer, the performance required of the heat-resistant material, the intended use, etc. In other words, soft carbon has individual crystallites arranged relatively regularly, and has a graphitized state compared to hard carbon.
1) It has the characteristic of being wet. In addition, pyrolytic carbon has a layered structure in which crystallites are highly oriented and has an airtight f! It is characterized by a large [. Of course, two or more types of these matrix carbons may be used in combination to exhibit intermediate properties.

The carbon fibers reinforcing the matrix carbon in the C-C composite layer may be polyacrylonitrile-based, rayon-based, or pitch-based.
It may be made of graphite. The single thread diameter of the carbon weave is 3
〜15μ, and its shape is 0.05〜15μ in length.
It may be short fibers of about 5ml1, preferably about 0.2 to 31mm, or it may be continuous 11M. In addition, C
Good too. The carbon fibers may be present in the matrix carbon as they are or in a defibrated state with completely random orientations (in the case of staple fibers, felt, or mats), or in any specific direction. (in the case of continuous fibers or woven fabrics).

The carbon forming the carbon material layer is also the soft carbon, hard carbon, pyrolytic carbon, etc. mentioned in F. Although the matrix carbon of the C--C composite layer may be different, it is usually composed of the same type of carbon.

These matrix carbon and carbon 1f (t to C-C
The method of manufacturing the composite layer is not particularly limited.

Next, let's take a look at a suitable example.

(a) Gas phase reaction method: carbon fibers of desired form are placed in a reaction apparatus and heated to 700 to 2000°C, preferably i ooo to 1
A method in which pyrolytic carbon is deposited on contact with a hydrocarbon gas such as propane or a mixed gas of that gas and hydrogen gas at a temperature of 500°C.

(0) High-pressure impregnation and firing method: carbon fibers in the desired form are placed in a pressure vessel, immersed in a carbonizable substance such as phenol resin, furan resin, pitch, etc. Using an inert gas such as
1-b/hour, preferably 50-b animals at 600-2000°C, preferably 1000-200°C
A method of carbonizing the above substance by heating it to 0°C.

(c) In the chamber impregnation atmospheric pressure sintering method, the carbonization i
The carbon fiber impregnated with the iJ-capable substance is taken out from the pressure vessel, and either as it is or after solidifying the substance, it is heated in a nitrogen gas stream and at normal pressure under the same temperature conditions as in the method 0 above to dissolve the substance. How to carbonize.

(d) Hot press method: Carbon fibers impregnated with the same carbonizable substance as in method O above, or a mixture of carbon fibers and the above substances, are heated using a Bot 1 press mold.
0 to 100 OK (J/cm2, preferably 100 to 10
600-・20 while applying a pressure of 0011 J/cm2
A method of carbonizing the above substance by heating at 00°C, preferably 1000 to 2000°C. 150-600 under the above pressure
℃, preferably 200 to 600℃, release the pressure, and further heat to 600 to 2000'C1, preferably 1
You may heat at 000-2000 degreeC.

C-G combos obtained by such a method 1~
The layer densifies the obtained C-C composite-a,
In order to further improve its mechanical properties, it is preferable to carry out the following treatments at least once.

■ Place the C-C composite in a sealed 111 container and reduce the pressure inside the container to several -4-n+mH (l or less) to expel any gas remaining inside.

(2) Next, a carbonizable substance such as a phenol resin, a run resin, and a bidi is poured into the container after being thoroughly vented, and the C--C composite is immersed in it.

In this case, the above-mentioned substance may be heated or diluted with a suitable solvent for the purpose of adjusting the viscosity.

■ Next, apply 10 to 1000 kg/cm2 inside the above container.
, preferably at a pressure of 100 to 1000 kg/cm 2 , and impregnate the above-mentioned substance into the voids inside the C-C compound body 1 .

■ Next, take out C-C Combobino 1- from the container,
The above substance is heated to 600 to 2800°C, preferably 1000 to 2500°C, in a flow of solidified non-irradiated gas such as nitrogen gas under normal pressure to carbonize the substance.

Additionally, these C-C-J bond layers can be layered to reduce voids or for mechanical reinforcement purposes.
Carbon powder having a particle diameter smaller than the single fiber diameter of the carbon fibers constituting and covering the composite layer may be filled into the gaps between the carbon fibers or the gaps between the carbon fibers and the MyJJ lux element.

In addition, the thickness of the C-C composite layer obtained by pressure molding expanded graphite is approximately 0.1 to 1 m.
It may also be a laminate or a composite in which a film or sheet graphite is interposed between the C--C composite. The C-G composite layer, which is a laminated or composite layer of flexible films or sheet graphite, can be molded and covered in various shapes, and is a heat-resistant material that is denser and has excellent heat resistance. can be obtained.

That is, for example, one graphite of film or sheet graphite commercially available from Union Carbye, Inc.
Films exhibit remarkable anisotropy in their thermal properties, with high thermal conductivity in the plane and low in the direction perpendicular to the plane. When sheet-like graphite is laminated or combined into a C--C composite layer, heat radiation from the outer surface of the heat-resistant material is effectively suppressed. In particular, at high temperatures exceeding 2000°C83, heat transfer is mainly through radiation, but heat dissipation from the surface can be further reduced by cutting this radiant heat; It is possible to reflect radiation inside and further improve the heat insulation effect.

The thickness of one layer of the C-C composite constituting the heat-resistant material of the present invention is about 0.05 to 10 mm, preferably 0.1 to 10 mm.
21IIIl range. Outside this range, the effect of preventing the ceramic layer from being worn out due to chemical reactions under high-temperature heating and cracking caused by that wearing down may not be sufficiently exhibited, and the ceramic layer and carbon material may not be sufficiently effective. The effect of stress relaxation due to the difference in thermal film rate between the layers may become insufficient.

The C--C composite layer has a density of at least about 0.50/cm2, preferably 1.50/cm2. O~2, Oq/c
By setting this density, the generation of inorganic gas from the ceramic layer during high-temperature heating is prevented, and this gas reaches the carbon material layer and reacts with carbon, forming a heat-resistant material. It becomes possible to prevent the formation of structural defects.

Furthermore, the thickness of the ceramic layer and the carbon material layer formed on both sides of the C-C combo 971 layer varies depending on the use of the heat-resistant material 1, but for example, in the case of a crucible,
It is preferable that the average thickness of the C1 ceramic layer is approximately 3 to 20 mm and the average thickness of the carbon material layer is approximately 10 to 40 mm, corresponding to the thickness of one layer of the -C composite.

Next, F! of the heat-resistant material of the present invention! 7. As for the manufacturing method, the simplest method is to separately mold the ceramic layer, C-C Combo 971 ~ layer, and carbon material layer in a predetermined shape, and then use them by laminating them! )1, but it is preferable to join these together. For example, the following method can be used to integrate the C--C composite layer and the carbon material layer.

Δ, a method in which the layer and the carbon material layer are bonded to the C-C combo body 1 prepared in advance with a carbonizable substance, and then heated to carbonize the substance and integrate the two (hereinafter referred to as A).
law).

B. A method of forming a carbon material layer on a C-C composite layer prepared in advance (hereinafter referred to as method 13).

C0 C-C of the carbon material layer prepared in advance
A method of forming a composite layer (referred to as IJ, below, C method).

D, a method of simultaneously forming a C-C composite layer and a carbon layer (hereinafter referred to as D method).

In the above method A, for example, a C-
The C composite layer and the carbon material layer are bonded with a carbonizable substance such as phenol resin, furan resin, or pitch, and then heated as is or after solidifying the above substance, in an inert gas stream such as nitrogen gas for 1 to 30 minutes. 600 to 2800°C, preferably 100°C at a heating rate of b
It is heated to 0 to 2,500°C to carbonize the above materials and materials and integrate the two. In this case, the above substance contains particles with a particle size of 0.
．． 1 carbonaceous or graphite 't9 carbon powder of 5-100μ
By mixing 0 to 100% by weight, more complete integration can be achieved. Further, when assimilating or carbonizing the above-mentioned substances, it is preferable to pressurize the adhesive surface at a pressure of about 1000 K CJ, /C1112 or less, in order to achieve more complete integration.

In method B, for example, prepared in advance lζC-C
The carbonizable material containing carbon powder in the above method may be added to the composite layer as it is, or methanol, acetic acid, etc.
The material is diluted with a solvent such as carbon, coated with carbon, and heated in the same manner as described below to carbonize the substance, thereby forming a carbon material layer on the C--C composite layer. In this case, the carbon powder may be a little larger, 0.5 to 200
A particle size of μ can be used.

Method B can also be implemented as follows.

That is, 700-2000°C, preferably 1000-2000°C
The C-C composite layer is placed in a furnace heated to a high temperature of 1500°C, and hydrocarbon gas such as propane, ethane, methane, or a mixed gas of these and hydrogen gas is flowed into the furnace to coat the surface of the C-C composite layer. Precipitates pyrolytic carbon. The thickness of the carbon material layer can be controlled by changing the gas composition, circulation time, furnace temperature, etc.

In method C, contrary to method B described above, a carbon material layer is first prepared in advance, and on top of the carbon material layer, continuous carbon fibers impregnated with carbonizable material Y4 similar to method A are formed. by filament winding method, or
Carbon ll1H fabric impregnated with the above substance, Fell 1~,
Laminating or wrapping the mats 1 - After applying the mixture with the carbon fiber short eave 1 such as the figurine Y1, heat the above substance in the same way as method A without applying pressure or with a pressurizer of 1000Kc7/cm2 or less. hardens to form a C-C composite layer. In this case, the content of the above substance is 2 for carbon IIN.
It may be 0 to 200% by weight. In addition, 10 carbonaceous or graphitic carbon powders having an average particle size of 0.5 to 10μ, preferably 1 to 3μ, which is smaller than the diameter of the carbon fiber, are added to the above substance.
By mixing up to 100% by weight, preferably 20 to 50% by weight, the carbon powder will penetrate between the carbon fibers or between the carbon fibers and the matrix carbon, resulting in a C-C composite layer with few voids. In method D, which is preferable because the mechanical strength of the heat-resistant material is further improved, a carbonizable material similar to method B is added on a layer formed in the same manner as in method C, which becomes a C-C composite when heated. and carbon powder, and heat in the same manner as in the following method to carbonize the carbonizable material in both layers, thereby simultaneously forming C-C composite layers 1 to 1 and a carbon layer. It is.

On the contrary, C may also be used by forming a layer that will become a C--C composite on a layer that will become a carbon material layer.

Furthermore, by forming the above-mentioned ceramic layer on the surface of the C-C composite layer of the composite of the C-C composite layer and the carbon material layer obtained as above by means of thermal spraying, vapor deposition, etc. It is possible to produce 1 q of heat-resistant material in which three layers are integrally bonded to each other.

Although the heat-resistant material of the present invention can be used for various purposes, it is particularly suitable as a material for high-temperature heating containers such as crucibles used in silicon single crystal pulling devices and various high-temperature heat treatment furnaces. .

1. The high temperature heat resistant monthly yield of the present invention will be explained by taking a crucible as an example.

Example Carbon fiber fabric 6343 (eye) 200G manufactured by Toshi Co., Ltd.
/m2) was coated with a 30% by weight MetaSeal solution of phenolic resin, dried at room temperature, cut into a disk shape with a diameter of about 500 mm, and divided into 3 disks to form a silicon single crystal. Place it in a metal mold that can be molded into the same bowl shape as the graphite crucible for the device, heat the stomach to 200°C at a heating rate of 100°C/hour while applying a pressure of 100K (J101112), and hold it at that temperature for 1 hour. The phenolic resin is cured, and the outer diameter is 300 mm, depth is 3 Q mm, and thickness is Q, 55 m.
A thin bowl-shaped carbon fiber-reinforced phenolic resin was used.

Next, the above carbon I! Fiber-reinforced phenolic resin at approximately 200℃
The phenol resin was kept for 100 hours to fully cure, and then heated in a nitrogen stream at a heating rate of 0°C/hour to 25°C.
The temperature was raised to 00°C, and the phenol resin was carbonized by holding it for about 1 hour.
91.

Next, put the C-C combo 1 into a pressure vessel,
The pressure inside the container was reduced to about 110l1lIllH, the above solution was injected, the pressure of about 100KO/c...2 was applied, the solution was impregnated into the above C-C composite 1~, and the solution was taken out from the container and heated at about 70℃ for 5 minutes. After heating and drying for about 20 hours,
Heat at 0°C for about 100 hours to avoid curing the phenol resin, and then raise the temperature to about 2500°C at a heating rate of about 0°C/hour in a nitrogen gas stream, and hold at that temperature for about 1 hour. The phenolic resin was carbonized. This operation was repeated three times to increase the density of the C--C composite.

The crucible for the silicon single crystal pulling device obtained in this way was placed in a graphite crucible, and a quartz crucible of the same shape was placed above it, solid crystals of silicon were placed in it, and the temperature was heated to approximately 1500°C. The single crystal was pulled up by heating. When the amount of molten silicon decreased to a certain extent, the heating test was stopped and the mixture was cooled to room temperature. This operation was repeated on the same crucible, but no abnormality was observed in the crucible.

Comparative Example When a quartz crucible was placed directly inside a graphite crucible and a silicon single crystal was pulled up in the same manner as in Example 1, the inside of the graphite crucible reacted with 3i02, and discoloration and wear due to the formation of SiC were observed. It was done.

When this operation was repeated, a slight rack was generated inside the crucible, and the crucible was worn out to a large extent, and there was a risk of breakage, so the experiment was discontinued.

[Brief explanation of the drawing]

Fig. 1 is a schematic sectional view showing an example of a silicon single crystal pulling device, and Fig. 2 is a schematic cross-sectional view showing an example of the high temperature heat resistant material of the present invention in a crucible for a silicon single crystal pulling device. FIG. 1: Crucible 2: Silicon melt 3: Silicon crystal 4: Heater 5: Heat insulation wall 0: Pyrometer 7: Heat treatment chamber E3: Gas inlet 9: Gas outlet 10: Ceramic layer 11: Carbon fiber reinforced carbon material layer 12: Carbon material Layer patent applicant Toshi Co., Ltd. Figure 1

Claims (3)

[Claims] (1) A high-temperature heat-resistant material comprising a laminated structure in which one layer of carbon fiber-reinforced carbon material is interposed between a carbon material layer and a ceramic layer. (2) The high-temperature heat-resistant material according to claim (1), wherein the ceramic layer is made of at least one selected from oxide ceramics, nitride reramixes, and carbide ceramics. (3) The density of the charcoal M mechanical fiber-reinforced carbon abrasive layer is at least 0.
, 5 g/am3, and its thickness is approximately 0°05
~lQn+m The high temperature heat resistant 1/F shrine according to claim (1).