JPH0333070A - Production of fiber reinforced ceramic composite material - Google Patents

Abstract

PURPOSE:To easily obtain the fiber reinforced ceramic composite material having high performance by impregnating an org. metallic polymer which is the precursor of a carbide-, nitride- or oxide-based ceramics in the tow of heat resistant fibers, putting the tow into an open type vessel and heat treating the same with a hot isostatic pressurization device. CONSTITUTION:The org. metallic polymer which is the precursor of the ceramics selected from carbide ceramics, nitride ceramics and oxide ceramics is prepd. The more specific examples of the org. metallic polymer include polycarbosilane, polysilazane, polysilastyrene, etc. This org. metallic polymer is then impregnated in the tow of the heat resistant fibers (e.g.; carbon fibers of a pitch). The tow is put into the open type treating material vessel and is heat treated in the hot isostatic pressurization device with a discharge mechanism. The tow is further heat treated under atm. pressure at need, by which the fiber reinforced ceramic composite material adequate for engine parts, etc., is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing a fiber-reinforced ceramic composite material.

(Problems to be solved by conventional technology and invention) 1! A ceramic composite material is a material in which ceramics, which is a matrix lath, is reinforced using carbon fibers. 41-fiber-reinforced Hiseramisox Asai material is a material with high fracture toughness that makes up for the shortcomings of morishic ceramics, which exhibit brittle fracture behavior, and is expected to be used in engine parts that require specific strength and heat resistance. has been done. However, its production method is based on the so-called CV I method, in which the ceramics are deposited by vapor phase vapor deposition into the fibers.
(Chemical Vapor Infiltrat
ion) method, etc., which requires an extremely long processing time and therefore increases manufacturing costs.

(Means for Solving the Problems) The present inventors have solved the above-mentioned problems and have completed the present invention as a result of research into a manufacturing process for ILI!! and high-performance annulus fibrosus ceramic composite materials. It's arrived.

The present invention includes (1) impregnating one part of a heat-resistant fiber with an organometallic polymer which is a precursor of at least one ceramic selected from the group consisting of carbide ceramics, nitrogen arsenide ceramics, and oxide ceramics; was placed in an open container and heat-treated in a hot isostatic presser.
A method for producing a fiber-reinforced ceramic composite material, which is further heat-treated at normal pressure if necessary, and (21)
For a carbon fiber-reinforced carbon composite material having an open porosity of 5 to 50%, an organic metal that is a precursor of at least one ceramic selected from the group consisting of carbide ceramics, nitride ceramics, and Pi (arsenic ceramics) is used. A method for producing a fiber-reinforced ceramic composite material, which comprises impregnating a polymer, placing the impregnated material in an open container, heat-treating it in a hot isostatic pressure device, and, if necessary, further heat-treating it at normal pressure.

The I-fiber-reinforced ceramic composite material according to the present invention will be described in detail below.

The organometallic polymer as used in the present invention is a precursor of at least one ceramic selected from the group consisting of carbide ceramics, nitrogen arsenide ceramics, and oxide ceramics. Specifically, they include polycarbosilane, polysilazane, polysilastyrene, metal alkoxide, alkyl metal, etc., and have a softening point of -50 to 400. 'C1
Preferably it is 0 to 350°C.

The heat-resistant fiber referred to in the present invention is carbon #! Fibers and Ceramics* Indicates fibers. The carbon fibers refer to pitch-based, polyacrylonitrile silicon, or rayon-based fibers, and pitch-based carbon AI fibers are particularly preferred. The pitch-based carbon fiber referred to here refers to carbon fiber obtained by melt-spinning carbonaceous pitch, making it infusible, carbonizing it, and graphitizing it if necessary.
It is. Ceramic fibers include charcoal such as SiC and TiC, nitrous ceramics such as Si3N4, or mixtures thereof. Even carbon! I! After coating the ceramic on the surface of the weed, it is then included.

In addition, heat-resistant fiber tow is a heat-resistant Il male with a diameter of 5 to 100 mm.
500,100,000 fiber bundles of 0 μm were formed into two-dimensional or three-dimensional products such as unidirectional laminates, two-dimensional fabrics or their i1-layer products, three-dimensional or more woven fabrics, mat-like molded products, felt-like preformed products, etc. say something Also, long fiber or short I
l! This includes both fiber and fiber.

In the present invention, the heat-resistant III fiber tow thus obtained is impregnated with an organometallic polymer, the impregnated product is placed in an open container, and the tow is placed in a hot isostatic pressing (HIP) device, preferably an exhaust mechanism. Heat treatment is performed in a HIP device. Impregnation is distantly related to heating and melting the organometallic polymer under vacuum and/or pressure, but it can also be cut back with a solvent to reduce the viscosity during impregnation. As a solvent, aromatic hydrocarbons, pyridine, and quinol can be used.

An open container is a container without a sealing function. Materials include metals such as aluminum, mild steel, and stainless steel.
Glass, graphite, ceramics, etc. can be selected as appropriate depending on the operating temperature or purpose of use. As long as it is an open type, the shape is not particularly limited, and it may be with or without a lid, and the object to be processed may be simply wrapped in metal foil.

According to the study results of the present inventors, when the organometallic polymer is heat-treated by hot isostatic pressing,
By using an open container and controlling the temperature inside the furnace or the temperature inside the furnace and the exhaust speed under limited conditions, the shape of the object to be processed can be maintained, and the dirt inside the furnace can be kept to a minimum, so it is not possible to use a closed container. It turns out that there is no need to use a mold container.

Moreover, when an open container is used, the internal pressure of the generated gas can prevent cracks from forming in the processed material. The open container may be filled with a material that physically captures the product, such as carbon felt, refractory felt, iron, titanium, or the like in the form of fibers.

A HIP device with an exhaust mechanism is a device that has a mechanism that can continuously control and exhaust the gas components generated from the object to be processed during HIP. This device is equipped with an exhaust mechanism that can adjust the removal amount depending on the speed. This gas exhaust mechanism includes a heat exchanger with the pressure medium gas inside the furnace, a cooler outside the furnace, a pressure reducing device, a flow rate control valve, and the like. More specifically, this device is described in Japanese Patent Application No. 1983-25317, which was filed by one of the applicants of the present application.

The conditions for pressurized heat treatment in a HIP device or a HIP device with an exhaust mechanism are 50 to 10,000 k with inert gas.
g/cnf, preferably 200-2000 kg/'
- pressurized to 100-3000℃, preferably 400℃
It can be carried out at 2000°C. As the pressure medium gas, an inert gas such as argon, nitrogen, helium, etc. can be used. The heat treatment under normal pressure following the pressurized heat treatment can be carried out at 400 to 2000°C in an inert gas atmosphere. Furthermore, when using a HIP device with an exhaust mechanism, a major feature is that it can be operated while analyzing the gas generated during heat treatment, and according to the results of the study by the inventors, It is desirable to carry out the heat treatment until the gas is substantially no longer produced. Here, "substantially no longer produced" means that the concentration in the exhaust gas is 10
ppm, preferably 5 ppm or less.

In the present invention, the production rate of each of H2 and CH4 in the exhaust gas is 10% per 100g of organometallic polymer.
Conditions such as not exceeding mol/hour, preferably 5.0 m
ol/hour, more preferably 2.0 mol 7 hours, most preferably 5.0 mol/hour. The temperature profile or temperature profile and pumping speed are controlled under conditions such that the temperature does not exceed Omol/hour, and heat treatment is performed under hot isostatic pressure.

Further, for densification, cycles of impregnation and HIP treatment can be performed as many times as necessary. The volume content of heat-resistant fibers in the composite material is arbitrarily determined depending on the purpose, but is usually 5 to 75 mo1%.

In order to further improve the oxidation resistance of the fiber-reinforced ceramic composite material obtained by the present invention, the surface thereof can be coated with ceramics.

The coating material is preferably at least one ceramic selected from the group consisting of carbide ceramics, nitride ceramics, and oxide ceramics, and the material to be cleaned is preferably CVD, PVD, etc.

EXAMPLES The present invention will be specifically explained with reference to Examples below, but the present invention is not limited thereto.

(Example 1) A two-dimensional fabric (plain weave) of 2,000 bundles of pitch-based carbon fibers with a diameter of 10 μm was laminated, and this was impregnated with polysilastyrene having a soft f-h point of 220°C. The impregnated material was wrapped in carbon felt and heated in a HIP apparatus with argon gas for 10 min.
It was pressurized to 00 kg/Cf11 and subjected to pressure conversion treatment at 800°C. The yield of impregnated polysilastyrene is about 70%, which is about 25% of that of the normal pressure conversion process.
significantly improved compared to. Following the pressurization plate 1H, heat treatment was performed at 1700° C. under normal pressure and an inert atmosphere. When the carbon fiber-strength ceramic composite material was examined using a scanning electron microscope, no cracks were observed within or between the fiber bundles, and the ceramic matrix was well filled. Further, no deformation or damage to the carbon fiber fabric was observed.

(Example 2) A two-dimensional fabric (plain weave) consisting of 2,000 bundles of pitch-based carbon fibers with a diameter of 10 μm was laminated, and this was impregnated with polysilastyrene having a softening point of 220°C.The impregnated material was wrapped in carbon felt. , pressurized to 1000 kg/cn! with argon gas in a hot isostatic pressure device with an exhaust mechanism, and
Pressure conversion treatment was carried out at ``C.Exhaust speed was 1.ONm.
'／It was time. The conversion yield of impregnated polysilastyrene is about 70%, which is about 25% of that of the normal pressure conversion process.
significantly improved compared to. When the equipment was opened and inspected after operation, it was found that there was very little dirt inside the furnace. Following the pressure conversion, heat treatment was performed at 1700° C. under normal pressure and an inert atmosphere. When the carbon fiber reinforced ceramic composite material was observed using a scanning electron microscope, no cracks were observed within or between the fiber bundles, and the ceramic matrix was well filled. Further, no deformation or damage to the carbon fiber fabric was observed.

(Example 3) A two-dimensional fabric (plain weave) consisting of 2,000 bundles of pitch-based carbon fibers with a diameter of 10 μm was laminated, and this was impregnated with polysilastyrene having a soft f point of 220°C.The impregnated material was covered with carbon felt. Then, it was pressurized to 1000 kg/cnl with argon gas in a hot isostatic pressure device with an exhaust mechanism, and the temperature was raised to 800°C at a rate of 2°C/min, and the pressure conversion treatment was performed at 800°C.The exhaust speed was 1, ON m. The production rate of H2 and CH4 in the produced gas was 0.58 mol/hour and 0.9 mol/hour per 100 g of polysilastyrene, respectively.
It was 6 mol at 7 o'clock. The obtained rolled product had many cracks. When the equipment was opened and inspected after operation, it was found that there was very little dirt inside the furnace. Following the pressure plate 1hi,
Heat treatment was performed at 1700° C. under normal pressure and inert atmosphere.

When the carbon fiber-strength 1-hyceramics composite material was observed using a scanning electron microscope, no cracks were observed within or between the fiber bundles, and the ceramic matrix was well filled. Further, no deformation or damage to the carbon fiber fabric was observed.

(Implementation ρ14) Carbon fiber whose surface was coated with SiC (manufactured by AVCO, USA)
5C3-6, diameter 14 μm) were laminated in one direction, and polysilastyrene having a soft f-h point of 220° C. was dissolved in xylene and impregnated therewith. The impregnated material is covered with carbon felt, and H
1000kg/c with argon gas in IP equipment
ut and subjected to pressure conversion treatment at 1000°C. The conversion yield of the impregnated polysilastyrene is approximately 70%, which is significantly improved compared to approximately 25% of that obtained by normal pressure rolling treatment. Heat treatment was performed at 1200°C. When the fiber strength 1 Hiserami-lux composite material was observed with a scanning electron microscope, no cracks were observed within the fiber bundles or between the 11-wire bundles, and the ceramic matrix was well filled.

Also, no deformation or damage to the carbon fiber fabric was observed.

<Example 5> Ceramic fiber (Si-C-Ti-0
1,600 bundles of Tyranno Fiber (manufactured by Ube Industries, Ltd.) and Cerami Nox 41 fiber (SiC type, manufactured by Ube Industries, Ltd.) with a diameter of 15 μm.
A bundle of 800 pieces of Nicalon (manufactured by Nippon Carbon Co., Ltd.) was treated in the same manner as in Example 4. When the obtained fiber-reinforced ceramic composite material was observed with a scanning electron microscope, no cracks were observed between the fiber bundles and the fiber bundles, and the ceramic matrix was well filled. Further, no deformation or damage to the carbon fiber fabric was observed.

(Actual example 6) Wealth 2s 1^sr ff1)', 7 handiwork Kishiryosuke no 2
A three-dimensional orthogonal fabric of 000 thick bundle was impregnated with an optically anisotropic pitch having a soft f-hit point of 280°C. The impregnated material was wrapped in a stainless steel foil, pressurized to 1000 kg/- with nitrogen gas in a HIP device with an exhaust mechanism, and heated at 0.5°C/min to 400°C at 1ooo°C while exhausting at 1.5 Nrd/h.
The temperature was raised at a rate of 2° C./min until the temperature reached 2° C., and the sample was treated with pressurized charcoal. The obtained carbon/carbon composite material had a porosity of 20%. This was impregnated with polysilastyrene with a softening point of 220°C, pressurized to 1000 kg/cut with argon gas in a HIP device, and treated with press paper at 1000''C.The obtained carbon fiber strong ceramic composite material was scanned. When observed using an electron microscope, it was found that the voids in the carbon/carbon composite material were well filled with a ceramic matrix.

No peeling of the matrix was observed.

(Example 7) A bundle of 2,000 pitch-based carbon fibers with a diameter of 10 μm was impregnated with a three-dimensional orthogonal 4a material having an optically anisotropic pi-sochi having a soft f-h point of 280°C.The impregnated material was wrapped in a stainless steel foil. ,
It was pressurized to 1000 kg/cnf in a HIP device with an exhaust mechanism, and treated with pressurized carbon at 1000°C. The obtained carbon/carbon composite material had a porosity of 20%. This was impregnated with polycarbosilane having a softening point of 232°C, pressurized to 1000 kg/- with argon gas in a HIP apparatus, and subjected to pressure conversion treatment at 1000°C. Following the pressure conversion, heat treatment was performed at 1350° C. under normal pressure and an inert atmosphere. When the obtained carbon fiber reinforced ceramic composite material was observed using a scanning electron microscope, it was found that the voids of the carbon/carbon composite material were well filled with the ceramic matrix, and no peeling of the matrix was observed.

(Example 8) A three-dimensional orthogonal fabric of 2,000 bundles of pitch-based carbon fibers with a diameter of 10 μm was impregnated with optically anisotropic pitch having a softening point of 280° C. The impregnated material was wrapped in a stainless steel foil, pressurized to 1000 kg/- in a HIP device with an exhaust mechanism, and
Pressure carbonization treatment was performed at 000°C. The obtained carbon/carbon composite material had a porosity of 20%. This is a soft "hi point 8"
Impregnated with polysilazane at 7°C, pressurized to 1000 kg/cnf with argon gas in a HIP device,
The sample was treated with pressure paper at 0°C.

Following pressure rotation, 1350° under normal pressure and inert atmosphere.
Heat treatment of C was performed. When the obtained carbon fiber strong ceramic composite material was observed using a scanning electron microscope (ISR), it was found that the voids of the carbon fiber composite material were well filled with the ceramic matrix, and no peeling of the 7-trix was observed. Ta.

<Example 9> Two bundles of 2000 pitch-based carbon 41 fibers with a diameter of 10 μm
Dimensional plain weave impregnated with phenolic resin. The impregnated product was dried and cured at 150°C to obtain a CFRP blow molded body. The blown body was heated at 1500°C in nitrogen for 1
A carbon composite material with a porosity of 25% was obtained by carbonization for a period of time. This was impregnated with polycarbosilane with a soft point of 232°C, wrapped in stainless steel foil, and pressurized to 1000 kg/cnl in an exhaust HIP device.The 10/carbon composite material had a porosity of 20%. there were.

Following the pressure conversion, heat treatment was performed at 1350° C. under normal pressure and an inert atmosphere. Carbon l obtained! When the fiber-reinforced ceramic composite material was observed with a scanning electron microscope, it was found that carbon 7
/ The voids of the carbon composite material were well filled with the ceramic matrix, and no peeling of the matrix was observed.

Claims (6)

[Claims] (1) A heat-resistant fiber tow is impregnated with an organometallic polymer, which is a precursor of at least one ceramic selected from the group consisting of carbide ceramics, nitride ceramics, and oxide ceramics, and the tow is placed in an open processing material container. A method for producing a fiber-reinforced ceramic composite material, which comprises heat-treating in a hot isostatic pressurizing device and, if necessary, further heat-treating at normal pressure. (2) The method for producing a fiber-reinforced ceramic composite material according to claim 1, wherein the hot isostatic pressure device is equipped with an exhaust mechanism. (3) A claim characterized in that the heat treatment in the hot isostatic pressurization device is performed under conditions such that the production rate of each of H_2 and CH_4 in the generated gas does not exceed 10 mol/hour per 100 g of organometallic polymer. A method for producing a fiber-reinforced ceramic composite material according to item 1. (4) For a carbon fiber-reinforced carbon composite material having an open porosity of 5 to 50%, an organic material that is a precursor of at least one ceramic selected from the group consisting of carbide ceramics, nitride ceramics, and oxide ceramics A method for producing a fiber-reinforced ceramic composite material, which comprises impregnating a metal polymer, placing the impregnated material in an open treatment container, heat-treating it in a hot isostatic pressure device, and, if necessary, further heat-treating it at normal pressure. (5) The method for producing a fiber-reinforced ceramic composite material according to claim 4, wherein the hot isostatic pressure device is equipped with an exhaust mechanism. (6) The heat treatment in the hot isostatic pressure apparatus is carried out under conditions such that the production rate of each of H_2 and CH_4 in the produced gas does not exceed 10 mol/hour per 100 g of organometallic polymer. A method for producing a fiber-reinforced ceramic composite material according to item 1.