JPH0597548A - Method for producing high-density material and apparatus therefor - Google Patents

Abstract

PURPOSE:To obtain a carbon material, etc., having high density in an extremely short time by carrying out a vapor-phase chemical reactional deposition under pressure. CONSTITUTION:A heat-insulation layer, having the shape of an inverted cup is placed in a high-pressure vessel 1 and a heater 8 is formed in the heat- insulation layer 7 to form a high-pressure high-temperature furnace chamber 10. A partition wall 11 is placed in the furnace chamber 10 to form a reactional chamber 13 in the furnace. The reactional chamber 13 has an inlet port 15 and an outlet port 16 to introduce and discharge a raw material gas for the vapor-phase chemical reaction.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to a method and apparatus for producing high density, eg, carbon / carbon composites, by vapor phase chemical infiltration.

[0002]

2. Description of the Related Art As a method for producing a high-density material, a method using pressure is generally known. Uniaxial pressure sintering by hot pressing, isotropic pressure sintering by hot isostatic pressing, and the like are widely used for densification of metals or ceramics. In addition, in the production of carbon / carbon composite materials, a method of high pressure impregnation carbonization in which pitch is impregnated and carbonized in a liquid phase under pressure is known.

On the other hand, there is known a vapor-phase chemical permeation method in which the above-mentioned impregnation is carried out under reduced pressure or atmospheric pressure in a vapor phase without using such a high pressure to increase the density.

[0004]

However, the conventional densification technique by the vapor phase chemical permeation method has a problem that it takes a very long time to densify the material (object to be treated). In view of the above-mentioned problems, it is an object of the present invention to provide a method and an apparatus capable of efficiently producing a high density material by performing a vapor phase chemical infiltration treatment under pressure.

[0005]

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention provides an inverted cup-shaped heat insulating layer 7 in a high-pressure vessel 1, and a heating body 8 in the heat insulating layer 7. A high-pressure high-temperature furnace chamber 10 is formed, and a partition wall 11 is provided in the furnace chamber 10 to define a reaction chamber 13 therein.
Is a method for increasing the density, characterized in that the source gas is introduced into and discharged from the reaction chamber 13 and vapor-phase chemical reaction vapor deposition is performed on the object to be processed 25 under pressure flow. Is.

In order to achieve the above-mentioned object, the present invention relating to the apparatus is provided with an inverted cup-shaped heat-insulating layer 7 in the high-pressure container 1, and a heating body 8 is provided in the heat-insulating layer 7 to provide a high-pressure high-temperature furnace chamber 10. And a partition wall 11 is provided in the furnace chamber 10 to form a reaction chamber inside.
It is characterized in that an inlet port 15 and an outlet port 16 for a source gas for defining 13 and for causing a gas phase chemical reaction in the reaction chamber 13 are provided.

[0007]

According to the present invention, the object to be processed 25 in the reaction chamber 13 is vapor-phase chemical reaction vapor deposition by a source gas having a pressure, that is, the gas-phase chemical reaction under pressure and further to the inside of the object to be processed 25. By utilizing the pressure as the pushing force of, the densification is efficiently performed.

[0008]

Embodiments of the present invention relating to an apparatus and embodiments of the present invention relating to a method will be described below with reference to the drawings. In FIG. 1 showing the first embodiment of the present invention relating to the apparatus, an upper lid 2 and a lower lid 3 are fitted into the upper and lower openings of a cylindrical high-pressure vessel 1, and airtightness is provided by seal members 4 and 5. The high pressure chamber 6 is formed by holding it. The axial force acting on the upper and lower lids 2 and 3 is not shown, but the upper and lower lids 2 and 3 are not shown.
It is carried by a swivel type or traveling dolly type press frame which is detachably engaged with the.

The high pressure chamber 6 has an inverted cup-shaped heat insulating layer 7
The heating element 8 is installed inside the heat insulation layer 7, and the temperature is raised and raised by introducing high-pressure gas from the passage 9 formed in the upper lid 2 and supplying electric power to the heating element 8 to raise the temperature.
A furnace chamber 10 for P treatment is formed. An inert gas such as argon is generally used as the introduction gas.

In the furnace chamber 10, an inverted cup-shaped partition wall 11 is fixedly installed on the lower lid 3 via a seal member 12 in the illustrated example, so that a reaction chamber 13 for carrying out vapor phase chemical reaction vapor deposition is formed. Well defined. In this case, it is desirable that the partition wall 11 be made of a metal material having no gas permeability in that the furnace chamber 10 and the reaction chamber 13 are strictly separated from each other. It is necessary to balance the pressure between the furnace chamber 10 that is operated and the reaction chamber 13 that performs reactive vapor deposition with a reactive gas.For example, by keeping the source gas pressure of the reaction chamber 13 constant with respect to the pressure of the furnace chamber 10. The partition wall 11 is prevented from being damaged by pressure.

The partition wall 11 has a gas-permeable material, for example,
It can also be made of porous ceramics or the like. In this case, the reaction gas (raw material gas) in the reaction chamber 13 is the heating element 8
Reaction chamber to prevent electrical contact from breaking electrical insulation.
The gas pressure inside 13 is controlled so as to be slightly lower than the pressure inside the furnace chamber 10, and the reaction gas is caused to flow while causing leakage of the inert gas through the partition wall 11.

A cylindrical heat insulating layer 14 is provided in the reaction chamber 13 on the lower lid 3.
Is provided, and in addition, the reaction to the reaction chamber 13 is
(Raw material) A gas inlet 15 and a gas outlet 16 are provided. An introduction conduit 18 screwed into the lower lid 3 via a seal member 17 is airtightly connected to the introduction port 15, and a distributor 20 having a large number of holes 19 is provided at the tip of the conduit 18. ..

On the other hand, the discharge port 16 has a lower cover 3 and a seal member 21.
A discharge conduit 22 screwed through is connected in an airtight manner, and a distributor 24 having a large number of holes 23 is provided at the upper part of the conduit 22. And the distributors 20, 24 facing each other up and down
The object to be treated 25 can be installed in between, while maintaining the pressure of the raw material gas constant with respect to the pressure in the furnace chamber 10,
In the process of introducing from the inlet 15 into the reaction chamber 13 and discharging from the outlet 16, the object to be treated 25 is densified by vapor-phase chemical reaction vapor deposition under pressure (permeation) as shown in Examples described later. ..

FIG. 2 shows a second embodiment of the present invention relating to the apparatus, in which a flat plate-shaped flange 22A is formed on the upper portion of the discharge conduit 22,
An object to be processed 25 is placed on the flange 22A via a seal member 26.
Is mounted, and the object to be processed 25 is attached by a holding plate 27 and bolts 28, etc. By adopting such an attachment member 29, not only the pressure is applied to the atmosphere but also the object to be processed 25 It is possible to increase the density by actively using it as penetration power,
This is particularly effective for the material to be treated having porosity. It should be noted that other components such as the introduction and discharge of the raw material gas are the same as those in the first embodiment, and the common parts are denoted by common reference numerals. However, the introduction and discharge of the raw material gas may be opposite to that shown in the figure.

FIG. 3 shows a third embodiment of the present invention relating to the apparatus, in which a pipe material is used as the object to be treated 25. In this case, from the outer surface to the inner surface of the pipe. , Or vapor-phase chemical reaction vapor deposition (penetration) from the inner surface to the outer surface. In addition,
The raw material gas is a gas containing a hydrocarbon-based gas such as methane gas or propane gas as a component gas, and a substance whose gas-phase chemical reaction is the synthesis of a carbon material can be given as an actual example (Example 1) In the equipment configuration shown in Fig. 1, a carbon material with a density of 1.398 (extruded material, φ60 x t6) was used as the object to be processed, and vapor phase chemical reaction vapor deposition was performed for 30 minutes under methane gas at 200 cc / min, 300 Torr and 1200 ° C. After that, when the surface vapor deposition layer was removed and the density was measured, the density was 1.403, which was a slight change.

On the other hand, the pressure is 9.5 kgf / cm ²
When the same experiment was conducted as above, the density became 1.443, and a clear density increase (effect of pressurization) was confirmed. In addition, methane gas 200cc / min, argon gas 1800c
When the pressure was set to c / min, the density was 1.441 under the pressure of 9.5 kgf / cm ^2, and it was confirmed that the same effect can be exhibited even by pressurizing with argon gas.

(Embodiment 2) The same material as in Embodiment 1 is used, with flexible graphite as a sealing member, and methane gas of 200 cc / min, 9.5 kgf / cm ² , 1 in the apparatus configuration of FIG.
After treatment for 30 minutes at 200 ° C (atmospheric pressure on the discharge side), the density after removal of the surface vapor deposition layer was 1.487, and the additional effect of pressure permeation was confirmed.

[0018]

The present invention is as described above. According to the method and apparatus of the present invention, it is possible to more efficiently pressurize, and to create a high-quality material or a material that is difficult under reduced pressure or atmospheric pressure. Therefore, it can greatly contribute to the creation of high-performance materials or new materials.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a first embodiment of the present invention relating to an apparatus.

FIG. 2 is a vertical sectional view of a second embodiment of the present invention relating to the apparatus.

FIG. 3 is a vertical sectional view of a third embodiment of the present invention relating to the apparatus.

[Explanation of symbols]

 1 High-pressure vessel 7 Heat-insulating layer 8 Heating element 10 Furnace chamber 11 Partition wall 13 Reaction chamber 15 Inlet port 16 Outlet port 29 Mounting member

Claims (5)

[Claims] 1. A high-pressure vessel (1) is provided with an inverted cup-shaped heat-insulating layer (7), and a heating body (8) is provided in the heat-insulating layer (7) to form a high-pressure high-temperature furnace chamber (10). And the partition wall (11) in the furnace chamber (10)
A method for increasing the density of the object to be treated (25) using an apparatus in which the reaction chamber (13) is defined inside the reaction chamber (13)
A method for producing a high-density material, characterized in that a raw material gas is introduced into and discharged from the inside of the material, and vapor phase chemical reaction vapor deposition is performed on the object (25) under pressure and flow. 2. A method for producing a high-density material, wherein the object to be treated (25) according to claim 1 has porosity. 3. The raw material gas according to claim 1 is a gas whose component gas is a hydrocarbon-based gas such as methane or propane,
The method for producing a high-density material according to claim 1 or 2, wherein the gas-phase chemical reaction is a synthesis of a carbon material. 4. A high-pressure vessel (1) is provided with an inverted cup-shaped heat insulation layer (7), and a heating body (8) is provided in the heat insulation layer (7) to form a high-pressure high-temperature furnace chamber (10). And the partition wall (11) in the furnace chamber (10)
Is provided to define a reaction chamber (13) inside, and an inlet port (15) for introducing a raw material gas for performing a gas phase chemical reaction in the reaction chamber (13)
And a discharge port (16) are provided. 5. Inlet (15) and outlet (16) according to claim 4.
5. The high density according to claim 4, further comprising a mounting member (29) for mounting a porous object (25) in a substantially airtight state via a seal member (26) on one side. Material manufacturing equipment.