JPH07286982A - Life prediction method and maintenance inspection method for ceramic structural parts - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a method of predicting the life of a ceramic structural component with improved reliability, or a method of diagnosing the life of various plants using this ceramic structural component, and further diagnosing and predicting the life directly. A possible ceramic structural component and its manufacturing method are provided. [Structure] A conductive circuit is provided on or near the surface of the ceramic structural component, an induced current is passed through the conductive circuit, and the life of the ceramic structural component is predicted based on the voltage change. Further, the amount of change in voltage change is compared with a threshold value, which is determined in advance, by the amount of voltage change indicating the life of the ceramic structural component, and when the amount of change in voltage change reaches the threshold value, the ceramic Maintain and inspect structural parts. Furthermore, this was applied to the life diagnosis of various plants. The present invention also relates to a ceramic structural component provided with the conductive circuit and a method for manufacturing the same.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for predicting the life of ceramic structural parts and a method for maintenance and inspection, which can judge the life under actual operating conditions, and further a gas turbine, a nuclear power plant, a fusion plant, an electromagnetic system. The present invention relates to a method for diagnosing the life of a plant that monitors the life of various plants such as a fluid power plant in the actual operating state, or a ceramic structural component capable of predicting the life and performing maintenance and inspection in the actual operating state, and a manufacturing method thereof.

[0002]

2. Description of the Related Art A major problem in applying conventional structural ceramics to actual structural parts is low reliability. Ceramics are superior in heat resistance, oxidation resistance, and wear resistance to metals, but their reliability is low due to their small fracture toughness (no stickiness), making them difficult to apply to actual structural components. There is. Up to now, as a method for solving this problem, a method of improving toughness (reference: “Si ₃ N ₄ —SiC whisker-based composite ceramics”, Ceramics, No. 12, 19)
83) or a method for confirming the progress of cracks by ultrasonic waves (reference; "Nondestructive evaluation technology for ceramics", ceramics,
No. 10, 1985) is being conducted.

As a method of determining the maintenance time of a gas turbine plant, for example, the life is calculated (Japanese Patent Laid-Open No. 59-3335), and the material to be measured is provided beside the actual machine structural parts. For example, there is a diagnosis by measuring the life (JP-A-57-113360). None of these methods directly diagnose the service life of the actual structural component itself, and are not accurate service life diagnosis methods. As a measuring means provided on the actual machine structural component itself, an electric measuring means mounted on the surface of the actual machine structural part is used to monitor the change over time in the crack depth (JP-A-56-75907). It has been known.

[0004]

In the above-mentioned prior art, no consideration is given to the life diagnosis of the actual structural components themselves, and there is a limit to the high reliability and the life diagnosis. Because, in the conventional method of improving the toughness, even if the particles are dispersed or the fiber is reinforced, the physical properties of the ceramic itself cannot be fundamentally changed, and the toughness is apparently improved, but the value is It is 1/5, and the reliability is still low. In addition, the method of confirming the crack development by ultrasonic waves, etc. can be measured at the test piece level, but to apply it to the actual machine structural parts, attach the sensor to the ceramic structural parts, add a measuring device, etc. However, it was not applicable in a heat resistant environment. Further, the method of not directly diagnosing the service life of the actual structural component itself has low reliability in using ceramics.

A first object of the present invention is to directly diagnose and predict the service life of a ceramic structural part which is an actual machine structural part, thereby predicting the service life of the ceramic structural part and predicting the service life of the ceramic structural part. Method and maintenance inspection method.

A second object of the present invention is to directly diagnose and predict the lifespan of structural parts made of a ceramic sintered body among the structural parts constituting various plants, and thereby to diagnose the lifespan of the plants. It is to provide a diagnostic method.

A third object of the present invention is to provide a ceramic structural component and its manufacturing method, which can directly diagnose and predict the life of the ceramic sintered body used in the ceramic structural component which is the actual structural component. .

[0008]

In order to solve the above-mentioned problems, the first aspect of the present invention is to provide a conductive circuit on or near the surface of a ceramic structural component, apply an induced current to the conductive circuit, and based on the voltage change thereof. To predict the life of the ceramic structural component.

According to the second aspect of the present invention, a conductive circuit having conductive ceramics is provided on or near the surface of the ceramic structural component, an induced current is passed through the conductive circuit, and the life of the ceramic structural component is extended based on the voltage change. To predict.

According to the third aspect of the present invention, a conductive circuit having carbon is provided on or near the surface of the ceramic structural component, an induced current is passed through the conductive circuit, and the life of the ceramic structural component is predicted based on the voltage change. That is.

According to the fourth aspect of the present invention, a conductive circuit having a metal is provided on or near the surface of the ceramic structural component, an induced current is passed through the conductive circuit, and the life of the ceramic structural component is predicted based on the voltage change. That is.

According to the fifth aspect of the present invention, a conductive circuit is provided on or near the surface of the ceramic structural component, an induced current is passed through the conductive circuit, the voltage change thereof is measured, and the change amount of the voltage change is determined in advance. By comparing with a threshold value represented by a voltage change amount indicating the life of the ceramic structural component, when the change amount of the voltage change reaches the threshold value, maintenance and inspection of the ceramic structural component can be performed. is there.

According to a sixth aspect of the present invention, in a gas turbine in which a turbine is rotated by combustion gas, at least one of a plurality of structural parts constituting the gas turbine is made of a ceramics sintered body, and the surface or the surface of the ceramics sintered body. A conductive circuit is provided in the vicinity, an induced current is passed through the conductive circuit, and the life of the ceramic sintered body is monitored based on the voltage change.

A seventh aspect of the present invention is, in a nuclear power plant utilizing energy generated by nuclear fission, at least one of a plurality of structural parts constituting the nuclear power plant.
And a conductive circuit provided on or near the surface of the ceramic sintered body, an induced current is passed through the conductive circuit, and the life of the ceramic sintered body is monitored based on the voltage change. Is.

According to the eighth aspect of the present invention, in a nuclear fusion plant that generates energy by nuclear fusion, a ceramic sintered body is provided on the side of at least one plasma of a plurality of structural parts constituting the nuclear fusion plant, Provide a conductive circuit on or near the surface of the ceramic sintered body,
An induced current is passed through the conductive circuit, and the life of the ceramic sintered body is monitored based on the voltage change.

According to the ninth aspect of the present invention, in a magnetohydrodynamic power generation plant in which high temperature gas plasma flows at high speed across a magnetic field to generate electric energy, the inner wall of the high temperature gas exhaust duct constituting the magnetohydrodynamic power generation plant is made of ceramics. A ceramics sintered body is provided with a conductive circuit on or near the surface thereof, an induced current is passed through the conductive circuit, and the life of the ceramics sintered body is monitored based on the voltage change.

The tenth aspect of the present invention is, in a ceramic structural part having a ceramics sintered body, a conductive material for generating an induced current, which is composed of at least one of carbon, ceramics and metal on or near the surface of the ceramics sintered body. The circuit is provided.

According to the eleventh aspect of the present invention, in a ceramic structural component having a ceramics sintered body, an induced current is formed on the surface of the ceramics sintered body or in the vicinity of the surface by at least one of carbon fiber, ceramic fiber and metal fiber. Is to provide a conductive circuit for.

The twelfth invention is the tenth invention or the eleventh invention.
In the invention, the conductive circuit has a terminal electrically connected to an external circuit of the conductive circuit.

The thirteenth invention is the tenth invention or the eleventh invention.
In the invention, the conductive circuit has a resistance value capable of being heated to a sufficient temperature for relaxing the thermal stress of the ceramic sintered body.

The fourteenth invention is the tenth invention or the eleventh invention.
In the invention, the relative permittivity of the conductive circuit is 30 or more, or the magnetic permeability of the conductive circuit is 1 or more.

The fifteenth invention is the tenth invention or the eleventh invention.
In the invention, the ceramic sintered body is made of at least one of oxide, nitride, carbide, carbonitride, oxynitride, boride, and silicide.

The sixteenth aspect of the present invention is, in a ceramic structural component having a ceramics sintered body, a conductive circuit is provided on or near the surface of the ceramics sintered body, and the conductive circuit is C and / or Si, Ti, A simple substance or a nitride, a carbide, a carbonitride made of any one of Zr, Cr, W and Mo,
It is composed of at least one of boride and silicide.

In the seventeenth aspect of the present invention, a composition for forming a conductive circuit for generating an induced current, which comprises carbon fibers and / or conductive ceramics, is provided on or near the surface of a molded body containing ceramic powder, and the molded body and Sintering the forming composition at the same time.

In the eighteenth aspect of the present invention, a composition for forming a conductive circuit for generating an induced current, which comprises carbon fibers and / or conductive ceramics, is provided on or near the surface of a molded body containing metal powder, and the molded body and Simultaneously sintering the forming composition in a nitriding, carbonizing, carbonitriding gas atmosphere.

The nineteenth aspect of the present invention is to provide a conductive circuit for generating an induced current, which is made of carbon fibers and / or conductive ceramics, on or near the surface of the ceramics sintered body after sintering.

[0027]

According to the first to fourth aspects of the present invention, a conductive circuit is provided on or near the surface of the ceramic structural component, an induced current is passed through the conductive circuit, and the life of the ceramic structural component is changed based on the voltage change. Therefore, when an alternating current is passed through the conductive circuit, there is no simple uniformity, and the current density becomes larger near the outer surface than the central part, which is caused by this induced current. The skin effect can reach the surface layer of the ceramic structural component. The magnitude of the non-uniformity of this induced current increases with increasing frequency. The skin effect is primarily due to the different self-induced electromotive forces that follow different paths in the conductor. Since these self-induced electromotive forces depend on the magnetic flux change rate, they increase with frequency. The electromotive force of the path that intersects with the minimum magnetic flux is the minimum. The number of internal crosslinks decreases as the frequency increases, making it possible to increase the skin effect. The resistance and voltage increase as the frequency increases. Now, when a crack is formed on the surface of the ceramic structural component, the distance due to the skin effect changes, so that the voltage changes.

Further, the present invention is provided with a conductive circuit containing conductive ceramics, carbon, metal, etc., and an induced current is generated on the surface of the conductive circuit or in the vicinity of the surface, which is caused by cracking, deformation, temperature, oxidation, corrosion, etc. Since it measures the voltage change,
A general conductive circuit material can be used to provide a conductive circuit having a large skin effect.

By arranging a plurality of rows of conductive circuits for generating an induced current in the ceramic structural component, the entire surface of the ceramic structural component can be detected. Further, this method of predicting the life of a ceramic structural component can be applied to a ceramic structural component having a complicated shape.

According to the fifth aspect of the present invention, a conductive circuit is provided on or near the surface of the ceramic structural component, an induced current is passed through the conductive circuit, the voltage change thereof is measured, and the change amount of this voltage change is obtained in advance. Compared with the threshold value represented by the amount of voltage change that indicates the life of the ceramic structure parts,
When the amount of change in voltage change reaches a threshold value, maintenance and inspection of the ceramic structural component are performed, so the change in voltage of the conductive circuit that generates the induced current is caused by the crack generated on the surface of the ceramic structural component. Measure this change,
Maintenance and inspection can be performed by comparing with the threshold value. If cracks occur on the surface of the ceramic structural component,
This causes the voltage to change. This value is read and compared with a threshold value by a computer provided outside, and when this threshold value is exceeded, maintenance and inspection of this ceramic structural component is performed. It is possible to prevent damage in advance, and this maintenance and inspection method greatly improves the reliability of ceramics.

According to the sixth to ninth aspects of the present invention, at least one of a plurality of structural parts constituting various plants is made of a ceramic sintered body, and a conductive circuit is provided on the surface of the ceramic sintered body or in the vicinity of the surface. , Since the induction current is passed through this conductive circuit and the life of the ceramics sintered body is diagnosed based on the voltage change, even if the conductive circuit is not provided for each structural component of the plant, the maximum stress is generated near the area and wear. The life can be monitored simply by installing it in the structural parts where
Further, since the conductive circuit is provided on the surface or in the vicinity of the surface, the skin effect is sufficiently generated on the surface of the structural component or in the vicinity of the surface. When a voltage fluctuation occurs due to a crack generated on the surface and the set threshold value is exceeded, it is determined that maintenance is required, the facility can be stopped, and the structural component can be replaced.

According to the tenth and eleventh aspects of the present invention, an induced current is formed on the surface of the ceramic sintered body or in the vicinity of the surface by at least one of carbon, ceramics, metal, or carbon fiber, ceramic fiber, and metal fiber. Since the conductive circuit for generation is provided, the skin effect generated in this conductive circuit can be fully exerted, and carbon, ceramics, metal or carbon fiber, ceramic fiber, metal fiber of this conductive circuit strengthens the ceramic sintered body. Has a function as a material.

According to the twelfth invention, in the tenth invention or the eleventh invention, the conductive circuit has a terminal electrically connected to an external circuit of the conductive circuit.
With the operation of the invention or the eleventh invention, it becomes easy to electrically connect to the external power source of the conductive circuit.

According to the thirteenth invention, in the tenth invention or the eleventh invention, since the conductive circuit has a resistance value capable of being heated to a sufficient temperature for relaxing the thermal stress of the ceramic sintered body, With the operation of the tenth invention or the eleventh invention,
It is possible to sufficiently heat the ceramics sintered body to have a function of relaxing thermal stress from the outside, and in particular, it is extremely effective for stress relaxation when sudden thermal stress occurs.

According to the fourteenth invention, in the tenth invention or the eleventh invention, since the relative permittivity of the conductive circuit is 30 or more or the magnetic permeability of the conductive circuit is 1 or more, the tenth invention or the eleventh invention. In addition to the action of the invention, a sufficient skin effect of the ceramic sintered body can be brought about.

According to the fifteenth invention, in the tenth invention or the eleventh invention, the ceramic sintered body is an oxide,
Since it is composed of at least one of nitride, carbide, carbonitride, oxynitride, boride, and silicide, the ceramic sintered body can be formed from a compact to a sintered body together with the action of the tenth invention or the eleventh invention. The dimensional change rate during sintering is as small as 1% or less, and the conductive circuit for generating induced current for life measurement oriented in the compact is oriented in the ceramic sintered body without deformation or cutting, No residual stress remains on the circuit itself.
Further, since the ceramics sintered body is porous, it becomes possible to coat and impregnate the surface and the inside with a substance satisfying the required characteristics when it is used for a structural part.
Furthermore, the surface of the ceramics sintered body is made of a dense wear-resistant material,
It can be made of a heat resistant material, a corrosion resistant material, or the like. The conductive circuit of SiC is effective for detecting surface cracks in heat resistant parts. In addition, rigidity can be increased as compared with a single substance by compounding and strengthening particle dispersion.

According to the sixteenth invention, a conductive circuit is provided on or near the surface of the ceramic sintered body, and the conductive circuit is any one of C and / or Si, Ti, Zr, Cr, W or Mo. Simple substance or nitride, carbide, carbonitride,
Since the ceramic sintered body is made of at least one of boride and silicide, the dimensional change rate at the time of sintering from the compact to the sintered body is as small as 1% or less, The conductive circuit is oriented in the ceramic sintered body without being deformed or cut, and no residual stress remains in the conductive circuit itself. Further, since the ceramics sintered body is porous, it becomes possible to coat and impregnate the surface and the inside with a substance satisfying the required characteristics when it is used for a structural part. Further, the surface of the ceramic sintered body can be made of a dense wear resistant material, heat resistant material, corrosion resistant material, or the like. Si
The conductive circuit of C is effective for detecting the surface crack of the heat resistant component.

According to the seventeenth aspect of the present invention, a composition for forming a conductive circuit for generating an induced current, which comprises carbon fibers and / or conductive ceramics, is provided on the surface or in the vicinity of the surface of the molded body containing ceramic powder, and the molded body is provided. Also, since the forming composition is sintered at the same time, it is possible to easily obtain a strengthened sintered ceramic sintered body at the same time.

According to the eighteenth aspect of the present invention, a composition for forming a conductive circuit for generating an induced current, which is composed of carbon fibers and / or conductive ceramics, is provided on or near the surface of a molded body containing metal powder, And since the forming composition is simultaneously sintered in a nitriding, carbonizing, carbonitriding gas atmosphere, the metal powder reacts with the reactive gas to produce a product,
By bonding this inorganic compound or this conductive circuit with the product, it is possible to manufacture a reaction-sintered ceramics sintered body in which a conductive circuit for generating an induced current having a porosity of 5 to 30 vol% is oriented.

According to the nineteenth aspect of the present invention, since the conductive circuit for generating an induced current made of carbon fibers and / or conductive ceramics is provided on or near the surface of the sintered ceramic body after sintering, the sintering treatment This makes it possible to provide a conductive circuit for generating an induced current that cannot withstand the sintering temperature as a conductive circuit.

[0041]

EXAMPLES Examples of the present invention will be described in detail below. The present invention provides a ceramic structural part with a conductive circuit having a one-dimensional or more-oriented orientation and a resistivity of 1 × 10 ¹ Ωcm or less, and an induced current is generated on the surface of the structural part by this conductive circuit to cause cracking, deformation, temperature, oxidation. The purpose of the present invention is to provide a life prediction method for predicting the life of this ceramic structural part by measuring the voltage change due to corrosion or the like, or a maintenance inspection method for performing maintenance and inspection.

The present invention allows high frequency current or electromagnetic waves to flow in the surface layer of the conductive circuit. The present invention can be achieved by allowing the skin effect generated in the conductor circuit to reach the surface layer of the ceramic structural component. When an alternating current is passed through the conductive circuit, there is no simple uniformity, and the current density is greater near the outer surface than at the center. The magnitude of this non-uniformity increases with increasing frequency. The skin effect is primarily due to the different self-induced electromotive forces that follow different paths in the conductor. Since these self-induced electromotive forces depend on the magnetic flux change rate, they increase with frequency. The electromotive force of the path that intersects with the minimum magnetic flux is the minimum. The number of internal crosslinks decreases as the frequency increases, making it possible to increase the skin effect. The resistance and voltage increase as the frequency increases.

FIG. 1 is a sectional view for explaining the skin effect generated around the conductive circuit. A conductive circuit for generating an induced current is provided in the sample 2, which is a ceramic matrix, and a skin effect 14 is generated around the conductive circuit 3. When a crack 10 is formed on the sample surface 12, the distance of the skin effect is changed, so that the voltage is changed. Changes occur. In this way, by arranging the conductive circuit 3 for generating an induced current in the sample 2, the entire sample surface can be detected. At this time, with respect to the portion where the skin effect 14 causes interference, the detection accuracy can be improved by taking this into consideration and correcting it by the controller.

FIG. 2 is a sectional view for explaining the skin effect that occurs around another conductive circuit. As shown in this figure, the conductive circuit 3 for generating an induced current in the ceramic matrix 1
By forming the surface layer 15 with a material composition having a relative dielectric constant of 30 or more or a magnetic permeability of 1 or more, a sufficient skin effect 14 can be provided. The relative permittivity and magnetic permeability can also be configured to be inclined from the surface layer 15. As a material composition having a high magnetic permeability, a ferrite compound, Cr
There are O ₂ , SrCoO ₃ , MnP, MoO, NiO and the like. Further, as a material composition having a large relative dielectric constant, SiC,
Examples include PZT type, PbTiO ₃ , LiTaO ₃ , and LiNbO ₃ .

According to the present invention, a conductive circuit for generating an induced current for life measurement provided in a ceramic structural part is made of C, Si.
It is composed of a continuous body such as C, TiN, TiC, ZrN, Cr ₂ N, W, Mo or the like having a low resistivity, particles or a thin film. It is also possible to combine conductive fibers and particles with heat-resistant insulating fibers and particles. Further, it is also effective for the life diagnosis to be composed of two or more kinds of fibers and particles having different elastic moduli. It is important that the conductive circuit for life measurement also serves as a reinforcing material for the ceramic structural parts. Materials include C, SiC, TiN, TiC, Z
In addition to simple substances such as rN and Cr ₂ N, C / SiC, C / Al ₂
O ₃ , C / Si ₃ N ₄ , C / Si ₂ N ₂ O, SiC / Si ₃ N
₄ , SiC / Si ₂ N ₂ O, SiC / Al ₂ O ₃ , TiN /
Composite of Al ₂ O ₃ , TiN / Si ₃ N ₄ , and TiN / Si ₂ N ₂ O is effective. In particular, in order to enhance the detection sensitivity, it is effective to form a ribbon or to combine a plurality of fibers together to make the skin effect uniform. Further, in order to bring a skin effect to the outermost surface layer, it is preferable to provide a conductive circuit for generating an induced current on the surface of the structural component or in the vicinity of the surface and to provide an environment-resistant coating having conductivity such as SiC. As a result, the skin effect can be brought up to the surface layer of the structural component.

Here, the combination of glass fiber and the above-mentioned conductive material is not applicable because of the problem that the glass fiber deteriorates due to the heat generated by the induced current. Therefore, it is important to composite the structure of the conductive circuit for measuring the life with the heat-resistant conductive fiber / particle and the heat-resistant insulating fiber / particle.

In the present invention, since a conductive circuit for measuring the life can be provided on the surface of the structural part or in the vicinity of the surface, it is possible to deal with a product having a complicated shape. Further, by using SiC as a conductive circuit for measuring the life, it is effective for detecting cracks on the surface of the heat resistant component.

In the present invention, the change in the voltage of the conductive circuit for generating the induced current for measuring the life is caused by the crack generated on the surface of the structural component, and the change is measured and compared with the threshold value to determine the life. Prediction, life diagnosis, maintenance diagnosis, etc. are possible. For example, when a crack is formed on the surface of the ceramic component, the voltage changes accordingly. Read this value, compare it with the threshold value by an external computer,
When the threshold is exceeded, a stop signal will be output automatically. This makes it possible to stop the equipment and replace the structural component before the ceramic structural component is destroyed.
In the present invention, this conductive circuit for life diagnosis can also serve as a reinforcing function of the ceramic structural component.

With the functionally fused structural component of the present invention, a change in voltage appears before the ceramic structural component is destroyed, and it is possible to prevent destruction and perform life diagnosis. This diagnosis can significantly improve the reliability of the ceramic structural component. This change in voltage is sent to the system, and when this value exceeds a predetermined threshold value, the system is automatically stopped and maintenance is performed. The conductive circuit for generating the induced current for life diagnosis in various machine structural parts need not be provided in all the various mechanical structure parts, but may be provided only in the vicinity where maximum stress occurs or on the surface where wear occurs. In addition, the conductive circuit for generating the induced current for the life diagnosis is on or near the surface (15 from the surface).
It must be provided within (mm). This is because the skin effect does not occur on the surface of the structural component when it is far from the surface. When a voltage fluctuation occurs due to a crack on the surface and it exceeds the set threshold value, it is judged that maintenance is required,
The equipment is stopped and parts are replaced.

The present invention further relates to oxides, carbides, nitrides,
By using a conductive circuit for generating an induced current for life measurement, which is configured in a mechanical structural part of a ceramic sintered body made of at least one type of carbonitride, as a heater for heating, it has a function of relaxing thermal stress from the outside. Found that it is possible. In particular, it is extremely effective for stress relaxation when a rapid thermal stress occurs.

The production method of this new functional ceramics sintered body is atmospheric pressure sintering, reaction sintering, HP, HIP, CVD, PV.
D, thermal spraying, etc. can be used. Particularly, atmospheric pressure sintering and reaction sintering are effective in terms of cost. As the ceramic sintered body, a ceramic sintered body having higher rigidity than that of a simple substance can be used by compounding and strengthening particle dispersion.

The present invention can be easily achieved especially by using the above-mentioned ceramics sintered body as a reaction-sintered ceramics sintered body made of at least one of oxide, carbide, nitride and carbonitride. The reason for this is that the reaction-sintered ceramics sintered body has a small dimensional change rate of 1% or less during sintering from the compact to the sintered compact. This is because the conductive circuit is oriented in the sintered body without being deformed or cut, and residual stress does not remain in the conductive circuit itself. Further, since the reaction-sintered ceramics sintered body is porous, it is possible to coat or impregnate the surface or the inside with a substance satisfying the required characteristics when it is used for a structural part. Various coating and impregnating methods such as CVD, CVI, PVD, ion implantation, and laser can be used. As a result, a conductive circuit for generating an induced current for life measurement is oriented inside, and a ceramic structural component in which the surface of a reaction-sintered ceramic sintered body is composed of a dense wear-resistant material, heat-resistant material, corrosion-resistant material, etc. I can.
Further, by using HIP together, densification can be achieved after reaction sintering.

The reaction-sintering ceramic structural component can be manufactured by molding a metal powder (Si, Al, etc.) or a molded product of the metal powder and at least one inorganic compound of oxide, carbide, nitride and carbonitride. A conductive circuit for generating an induced current having a resistivity of 1 × 10 ¹ Ωcm or less, which has a one-dimensional or more orientation, and is at least one of nitriding property, carbonizing property, carbonitriding property, oxidizing property, and oxynitriding property. The metal powder reacts with the reactive gas to produce a product by heating in a reactive gas atmosphere consisting of, and the porosity of 5 is obtained by binding the inorganic compound and the conductive circuit with the product. ~
It is possible to manufacture a reaction-sintered ceramic structural component in which a conductive circuit for generating an induced current of 30 vol% is oriented. Cutting, deformation, temperature, oxidation of the surface of this ceramics sintered body,
By measuring the voltage change due to corrosion or the like, it is possible to diagnose the life of this ceramic sintered body.

As another manufacturing method of the present invention, a green sheet molding method is advantageous for a low cost manufacturing method. This is a method of forming a green sheet with a doctor blade using a slurry composed of an organic binder and ceramic powder, cutting it into an arbitrary shape by punching, and sintering. A suitable thickness of the green sheet is 1 mm to 5 mm, but an arbitrary thickness is possible depending on the shape of the parts, and the green sheets are stacked. After sintering, finish processing is performed if necessary.

The induction current circuit provided in the ceramic sintered body and the wiring can be connected by brazing, laser, ultrasonic wave or the like. Also, by coating the surface of metal wiring such as copper, tungsten, platinum, etc. with ceramic,
The wiring itself can have heat resistance.

Next, a specific application example will be described in more detail with reference to the drawings.

[Embodiment 1] FIG. 3 shows a voltage measuring circuit for life monitoring of a first wall structural component of a fusion reactor in a nuclear power plant system, (A) is a principle diagram of the voltage measuring circuit, and (B).
FIG. 3A is a sectional view taken along line I-I of FIG. 100 parts by weight of SiC powder having an average particle diameter of 1 μm and B ₄ C as raw materials of the ceramic matrix 1 which is a ceramic structural component constituting the first wall of the fusion reactor in the nuclear power plant system 18
13 parts by weight of a mixture of polyethylene, stearic acid and synthetic wax was added to 3 parts by weight of the powder and kneaded to obtain a raw material.
Using an extrusion molding machine, this raw material is 2 mm thick and 100 m thick.
An m-square plate was prepared. Carbon fiber (diameter 1
0 μm, length 1000 μm) (bundle diameter 5 mm) are arranged at intervals of 5 mm as the conductive circuit 3 for measuring voltage for life diagnosis.
A test piece was prepared. As described above, it is necessary to form the conductive circuit for generating the induced current in accordance with the distance reached by the high frequency current due to the skin effect generated by the induced current. This makes it possible to search for cracks wherever they occur by means of voltage fluctuations. Also, the wire diameter of the conductive circuit 3 for generating the induced current for life diagnosis is preferably 0.1 mm or more in terms of handling. Reference numeral 5 is a high frequency power source, and 6 is a voltage change measuring device.

The above-mentioned molded body was heated in an Ar atmosphere furnace to 2050 ° C. at a temperature rising rate of 5 ° C./min, and allowed to cool in the furnace to burn SiC ceramics having a conductive circuit for measuring voltage for life diagnosis. I got a union. The degreasing of the binder and the like is performed during the temperature rising process. Then, a copper wiring was silver brazed to the end portion of the internal circuit, wiring was performed to an external power source and a measuring instrument, and the wiring was connected to the nuclear power plant system 18.

This ceramic structural component was applied to a fusion reactor first wall structural component simulated test by a simulated plasma device. As a result, the surface of the ceramic structural component is destroyed by neutron irradiation, and a voltage change appears as shown by the relationship curve 21 between the neutron irradiation time and the voltage change rate shown in FIG. Life diagnosis of parts is possible. This change in voltage is applied to the nuclear power plant system 1
8 and when this change exceeds a predetermined threshold value 4, the nuclear plant system 18 is automatically stopped,
Perform maintenance.

FIG. 5 is a sectional view of a ceramics sintered body for life monitoring of the first wall structural component of the fusion reactor. As shown in this figure, a conductive circuit 3 is formed on the surface of the fusion reactor first wall structural component 1.
It is also possible to arrange. The life diagnosis can be performed from both the detection of the voltage change due to the induced current and the change of the resistivity of the diagnostic circuit.

The ceramics sintered body of the present invention can be molded according to various parts shapes such as doctor blade, mold powder molding, CIP, injection molding, casting molding, extrusion molding and the like.

The molding binder such as the green sheet is generally used as a binder for molding ceramics such as a polymer material such as polyvinyl butyral and polyethylene, a silicone compound and a polysilane compound. Things can be used. The degreasing method of these binders is not particularly limited, but degreasing can be performed by controlling the temperature rising rate during sintering.

The method of this embodiment can also be applied to an insulating wall for MHD power generation.

[Embodiment 2] FIG. 6 shows another voltage measuring circuit for life monitoring of the first wall structural component of the fusion reactor, (A) is a principle diagram of the voltage measuring circuit, and (B) is (A). 2 is a sectional view taken along line II-II of FIG. As raw materials for the ceramic matrix 1 which is the new functional ceramic structural component of Example 2, 97 parts by weight of AlN powder having an average particle size of 0.1 μm and a sintering aid Y ₂ O ₃ :
13 parts by weight of a mixture of polyethylene, stearic acid and synthetic wax was added to 3 parts by weight and kneaded to obtain a raw material. A plate having a thickness of 2 mm and a 100 mm square was produced from this raw material using an extrusion molding machine. Carbon fiber (diameter 100
μm, length 1000 μm) and Al ₂ O ₃ fiber (diameter 100 μm
m, length 1000 μm) of composite long fibers (diameter 8 mm) were molded and formed at intervals of 5 mm as the conductive circuit 3 for generating induced current for life diagnosis. Carbon fiber and Al used in the circuit
The compounding ratio of ₂ O ₃ fiber is 70:30 vol%.

The above molded body was heated to 1800 ° C. at a temperature rising rate of 1 ° C./min in a nitrogen atmosphere, held for 3 hours, and then allowed to cool in a furnace to carry out pressureless sintering having a voltage measuring circuit for life diagnosis. An AlN ceramic matrix 1 was obtained. The degreasing of the binder and the like is performed during the temperature rising process. On the surface layer portion of the obtained pressureless sintered AlN ceramics, a film 0.5 mm of a dense coating layer 8 of SiC was formed by plasma spraying to have neutron resistance. Then, a copper wiring was silver brazed to the end portion of the internal circuit, wiring was performed to an external measuring device, and connection was made to the nuclear power plant system 18.

The ceramic matrix 1 which is the present ceramic structural component was applied to the fusion reactor first wall structural component of the simulated plasma device. The conductive circuit 3 for induced current for life diagnosis was provided inside the surface SiC film of the first wall structural component. The life diagnostic circuit was extended to the cooled substrate and connected to the copper wire. The area around the connection between the copper wire and the life diagnosis circuit is Al ₂ O ₃
Covered with a protective tube.

As a result, the SiC film of the ceramic matrix 1 is destroyed by neutron irradiation, and a voltage change as shown in FIG. 4 appears, so that the life of the fusion reactor first wall structural component can be diagnosed. This change in voltage is sent to the nuclear power plant system 18, and when this voltage exceeds a predetermined threshold value 4 (FIG. 4), the nuclear power plant system 18 is automatically stopped and maintenance inspection is performed. Not limited to the present embodiment, it is extremely effective as nondestructive detection when the outermost environmental resistance layer is destroyed.

Instead of the above AlN powder, Si ₃ N ₄ , S
_{i 2 N 2 O, Al 2} O 3, ZrO 2, B 4 C, BN, new functional ceramics having a voltage measuring circuit for life diagnosis in the same manner by using a mullite powder and the like _{(Si 3 N 4, Si 2} N 2 O, Si
C, Al ₂ O ₃ , ZrO ₂ , B ₄ C, BN, mullite, Si
₃ N ₄ / SiC composite material, Al ₂ O ₃ / ZrO ₂ composite material, SiC /
Al ₂ O ₃ composite material, Si ₃ N ₄ / ZrO ₂ composite material, Si ₃ N ₄ /
Al ₂ O ₃ composite material, Si ₃ N ₄ / BN composite material, mullite / Si
C composite material and ZrO ₂ / BN composite material) were produced by an atmospheric pressure sintering method and applied to the first wall structural component of the fusion reactor. as a result,
The same results as in FIG. 4 were obtained, and it was found that life diagnosis was possible. Reference numerals 5 and 6 in FIG. 6 are a high frequency power source and a voltage change measuring device, respectively.

[Embodiment 3] FIG. 7 shows a voltage measuring circuit for monitoring the life of a stationary component for a gas turbine. (A) is a principle diagram of the voltage measuring circuit, (B) is III-III of (A). It is a line sectional view. A study was carried out on a gas turbine moving blade component of the ceramic matrix 1 which is a ceramic structural component in the thermal power plant system 19. 100 parts by weight of Si ₃ N ₄ powder having an average particle size of 0.5 μm was used as a raw material of the ceramic matrix 1 which constitutes a moving blade part for gas turbine
Y ₂ O ₃ 5 parts by weight, Al ₂ O ₃ 5 parts by weight, polyvinyl butyral 6 parts by weight, trichloroethylene 24 parts by weight, tetrachloroethylene 32 parts by weight, n-butyl alcohol 4
108 parts by weight of a binder composed of 4 parts by weight and 2 parts by weight of butyl phthalylglycoyl butylate were added, and 2 parts were added by a ball mill.
Mix for 4 hours to make a slurry.

The slurry was vacuum degassed to remove air bubbles, and then the slurry was poured into a rubber mold having a stationary blade shape of a gas turbine by a casting molding method and dried for 10 hours to prepare a molded body. . In addition, a predetermined pattern is
A carbon / SiC composite fiber (diameter 3 mm) was formed on the outermost surface layer as a conductive circuit 3 for generating an induced current, and the slurry was poured around it.

The molded body was heated in a nitrogen atmosphere furnace to 1750 ° C. at a temperature rising rate of 5 ° C./min, allowed to cool in the furnace, and Si having a conductive circuit for measuring life monitoring voltage near the surface. _{A 3} N ₄ ceramics sintered body was obtained. On the surface layer portion of the obtained ceramics sintered body, a film 1 mm of a dense coating layer 8 of SiC / ZrO ₂ (80/20 vol%) was formed by thermal spraying to have a skin effect. Then, the life diagnosis circuit was extended to the turbine disk, the tungsten wiring was brazed to the end of the circuit, the wiring was connected to an external measuring instrument, and the circuit was connected to the thermal power plant system 19. Reference numerals 5 and 6 represent a high frequency power source and a voltage change measuring device, respectively. Reference numerals 5 and 6 in FIG. 7 are a high frequency power source and a voltage change measuring device, respectively.

FIG. 8 is a relationship curve diagram between the gas turbine operating time and the voltage change rate. The ceramic matrix 1 which is this functional ceramic structural component was applied to a gas turbine moving blade component. The change in voltage as shown by the curve 22 appears, and the life diagnosis becomes possible before the ceramic matrix 1 is destroyed. Due to this life diagnosis, the reliability of ceramics was significantly improved. This change in voltage is sent to the thermal power plant system 19, and when the rate of change in voltage exceeds a predetermined threshold value 4 (FIG. 8), the thermal power plant system 19 is automatically stopped and maintenance inspection is performed.

In the present invention, the film of the coating layer 8 for densifying the surface layer portion of the ceramic is SiC,
BN, TiN, ZrO ₂ , diamond, ZrB _{2 and the} like can be provided with an arbitrary multilayer film depending on the use environment and purpose.

[Embodiment 4] The turbine vane parts for the gas turbine in the thermal power plant system were examined. Polyvinyl butyral was added to 96 parts by weight of SiC powder having an average particle size of 0.5 μm, 4 parts by weight of B ₄ C powder having an average particle size of 0.2 μm, as a raw material of ceramic structural parts constituting a stationary blade part for a gas turbine. 6 parts by weight, 24 parts by weight of trichloroethylene, 32 parts by weight of tetrachloroethylene, 44 parts by weight of n-butyl alcohol, 108 parts by weight of a binder composed of 2 parts by weight of butyl phthalylglycoyl butylate were added and mixed in a ball mill for 24 hours. And make a slurry.

The slurry was vacuum degassed to remove air bubbles, and then the slurry was poured into a rubber mold having a vane shape of a gas turbine by using a casting method, and carbon / SiC composite fiber was used as in Example 3. (Diameter 3 mm) was formed as a conductive circuit for life diagnosis, and slurry was poured around it.

The molded body was placed in a furnace in an argon atmosphere,
SiC with a conductive circuit for measuring lifespan voltage by heating to 2250 ° C at a heating rate of 5 ° C / min and allowing to cool in a furnace
A ceramic sintered body was obtained. The surface layer portion of the obtained ceramics sintered body was sprayed with Z to obtain heat resistance.
A dense coating layer film of 500 μm of rO ₂ was formed. Then, a tungsten wiring was brazed to the circuit end portion, wiring was performed to an external measuring device, and the wiring was connected to the thermal power plant system.

The functional ceramic structural part was applied to a stationary blade part for a gas turbine. As a result, before the ceramic structural component is destroyed, as shown by the curve 22 in FIG. 8 described above, a change in voltage appears, and the life can be diagnosed. By this diagnosis, the reliability of the ceramic sintered body was significantly improved. It is possible to send this change in voltage to the thermal power plant system, automatically stop the thermal power plant system when the resistance value exceeds a predetermined threshold value, and perform maintenance inspection. The conductive circuit for diagnosing the life of the blade may not be provided on the entire blade, but may be provided only near the maximum stress. Further, it is necessary to provide the conductive circuit for life diagnosis on the surface or in the vicinity of the surface (within 5 mm from the surface). Because ceramic structural parts
This is because it is necessary to sensitively detect the occurrence of cracks on the surface because cracks form from the surface and linear fracture occurs.

[Embodiment 5] As raw materials for a ceramic matrix which is a new functional ceramic structural component, 95 parts by weight of Si ₃ N ₄ powder having an average particle diameter of 0.1 μm and a sintering aid Y ₂ O are used.
₃ : 3 parts by weight, AlN: 2 parts by weight, polyvinyl butyral 6 parts by weight, trichloroethylene 24 parts by weight, tetrachloroethylene 32 parts by weight, n-butyl alcohol 44
And 108 parts by weight of a binder composed of 2 parts by weight of butyl phthalyl glycol-butylate and 24 parts by ball mill.
Mix for time to make a slurry.

This slurry was vacuum degassed to remove air bubbles, and then the slurry was poured into a rubber mold having a shroud segment shape of a gas turbine by using a casting method.
It dried for 10 hours and created the molded object. In the rubber mold, a C / Al ₂ O ₃ composite fiber bundle (diameter 5
mm) was formed as a conductive circuit for generating an induced current for life diagnosis, and the slurry was poured around it.

The molded body was heated to 1750 ° C. at a temperature rising rate of 5 ° C./min in a furnace in a nitrogen atmosphere, held for 3 hours, and then allowed to cool in the furnace to produce a conductive material for generating an induced current for life diagnosis. An atmospheric pressure sintered Si ₃ N ₄ ceramics sintered body having a circuit was obtained. On the surface of the obtained pressureless sintered Si ₃ N ₄ ceramics sintered body, a film having a dense coating layer of SiC of 10 μm was formed by thermal spraying so as to have heat resistance. Then, the life diagnosis circuit was extended to the outside of the turbine casing, copper wiring was brazed to the end of the turbine casing, wiring was performed to an external measuring instrument, and connection was made to the thermal power plant system. The life diagnostic circuit and the copper wiring were insulated with an alumina protective tube.

The functional ceramic structural part was applied to a shroud part for a gas turbine. As a result, before the ceramic structural parts are destroyed, the curve 22 in FIG.
As described above, a change in voltage occurs, and life diagnosis can be performed.
By this diagnosis, the reliability of the ceramic sintered body was significantly improved.

Furthermore, instead of the above Si ₃ N ₄ powder, Si
C, Si ₂ N ₂ O, AlN, Al ₂ O ₃ , ZrO ₂ , B ₄ C,
BN, mullite powder, etc. are also used for the functional fusion structure ceramics (Si ₃
N ₄ , Si ₂ N ₂ O, AlN, Al ₂ O ₃ , ZrO ₂ , B
₄ C, BN, mullite, Si ₃ N ₄ / SiC composite material, Al ₂
O ₃ / ZrO ₂ composite material, SiC / Al ₂ O ₃ composite material, Si ₃ N ₄
/ ZrO ₂ composite material, Si ₃ N ₄ / Al ₂ O ₃ composite material, Si ₃ N ₄ /
A BN composite material, a mullite / SiC composite material, and a ZrO ₂ / BN composite material) were produced by the HIP sintering method and applied to a shroud part for a gas turbine. As a result, a result similar to the curve 22 in FIG. 8 was obtained, and it was found that the life diagnosis was possible, and it was also found that the HIP could manufacture a new functional ceramic structural component. This embodiment is also applicable to gas turbine engine parts.

[Embodiment 6] FIG. 9 is a principle diagram showing a voltage measuring circuit for monitoring the life of parts for corrosion resistant piping.

As a raw material for the ceramic matrix 1 which is a new functional ceramic structural part, the average particle size is 0.1 μm.
m SiC powder 97 parts by weight and sintering aid B ₄ C: 3 parts by weight, AlN: 2 parts by weight, polyvinyl butyral 6 parts by weight, trichloroethylene 24 parts by weight, tetrachloroethylene 32 parts by weight, n-butyl alcohol. 108 parts by weight of a binder composed of 44 parts by weight of butyl phthalylglycolate and 2 parts by weight of butyl phthalyl glycolate butylate are added and mixed in a ball mill for 24 hours to obtain a slurry.

The slurry was vacuum degassed to remove air bubbles, and then the slurry was poured into a porous mold (gypsum), and a pipe having a thickness of 10 mm and a diameter of 150 mm was produced using a centrifugal molding machine. The porous type surface has a predetermined pattern of 90 vol% carbon and 10 vol% SiC composite fiber.
(Diameter 5 mm) was formed as the conductive circuit 3 for measuring the voltage for life diagnosis, and the slurry was adhered around it. After removing the wax content in the molded body, 210 in Ar gas
Heat treatment was performed at 0 ° C. for 3 hours. As a result, the conductive circuit 3 for measuring the voltage for life diagnosis can be provided in the pipe.

The ceramic matrix 1, which is the functional ceramic structural component, was applied to a corrosion-resistant piping component of a thermal power plant. As a result, before the ceramic structural component is corroded and broken, as shown in the relationship curve 23 between the chemical (alkali, acid) corrosion time and the voltage change rate in FIG. 10, the voltage change appears and the voltage change rate is When the threshold value reaches 4, maintenance and inspection can be performed and life diagnosis can be performed. This life diagnosis greatly improved the reliability of the ceramic sintered body. Further, as shown in the embodiment of the conductive circuit installation of the ceramic matrix 1 which is the pipe-shaped component in FIG. 11, it is possible to provide the conductive circuit 3 for measurement on the inner diameter side of the pipe.

Instead of the above SiC powder, Si ₃ N ₄ , S
i ₂ N ₂ O, AlN, Al ₂ O ₃ , ZrO ₂ , B ₄ C, BN,
A new functional ceramics sintered body (Si ₃ N ₄ , Si) having a conductive circuit for life diagnosis similarly using mullite powder or the like.
₂ N ₂ O, AlN, Al ₂ O ₃ , ZrO ₂ , B ₄ C, BN, mullite, Si ₃ N ₄ / SiC composite material, Al ₂ O ₃ / ZrO ₂ composite material, SiC / Al ₂ O ₃ composite material , Si ₃ N ₄ / ZrO ₂ composite material, Si ₃ N ₄ / Al ₂ O ₃ composite material, Si ₃ N ₄ / BN composite material,
A mullite / SiC composite material and a ZrO ₂ / BN composite material) were produced by an atmospheric pressure sintering method and applied to a corrosion-resistant pipe component. As a result, the same result as that shown in FIG. 10 was obtained, and it was found that life diagnosis was possible.

The above-mentioned new functional ceramic structural parts were applied to chemical resistant piping. As a result, before the ceramic structural parts are corroded and destroyed by chemicals (alkali, acid), a change in voltage appears as shown in FIG. 10 and the service life can be diagnosed. By this diagnosis, the reliability of the ceramic sintered body was significantly improved.

As a method of providing a voltage measuring circuit on a cylindrical part such as a pipe, a method of orienting the measuring circuit in a mold in advance or a measuring circuit composed of a fiber such as carbon and a medium on the surface of a ceramic green sheet is used. With
After stacking this green sheet, it is molded into a cylinder,
Various methods such as sintering, coating a conductive film on the surface of the ceramic green sheet, laminating this green sheet, forming it into a cylinder, and sintering, etc. The measurement circuit of can be provided.

The method of the sixth embodiment includes a pump stator,
It can also be applied to pump casings, powder / particle transport pipes, cock valves, nozzles, valves, crucibles, and the like.

[Embodiment 7] As a raw material for a functionally fused ceramic structural part, 13 parts by weight of a mixture of polyethylene, stearic acid and synthetic wax was added to 100 parts by weight of metal Si powder having an average particle diameter of 1 μm and kneaded to obtain a raw material. . A plate having a thickness of 10 mm and a size of 100 mm square was produced from this raw material using an extrusion molding machine. Carbon fiber (diameter 10 μm,
Length 1000μm) and Al ₂ O ₃ fiber (diameter 5μm, length 1
000 μm) and SiC fiber (diameter 10 μm, length 100 μm
The composite long fiber (diameter 5.5 mm) of m) was molded and formed as a conductive circuit for measuring voltage for life diagnosis. The compounding ratio of carbon fiber, Al ₂ O ₃ fiber and SiC fiber used for the conductive circuit for life diagnosis is 30:50:20 vol%.

The above molded body was heated in a furnace in a nitrogen atmosphere at a temperature rising rate of 1 ° C./min to 1350 ° C., and allowed to cool in the furnace to carry out reaction sintering Si having a conductive circuit for measuring voltage for life diagnosis. ₃
An N ₄ ceramics sintered body was obtained. The surface layer of the obtained reaction-sintered ceramics sintered body was subjected to plasma spraying in order to have heat resistance by SiC / ZrO ₂ (80/20 vol).
%) Dense coating layer film 0.3 mm was formed.
Since the surface layer of the reaction-sintered material is porous, SiC / ZrO ₂ also penetrates into the pores of the material to obtain a film having high adhesive strength. Then, copper wiring was brazed to the end of the conductive circuit, and the wiring was connected to an external measuring device.

The ceramic structural component was applied to a combustor lining component of a gas turbine. As a result, the ceramic structural component is cracked in the SiC / ZrO ₂ film by the combustion test, and a change in voltage appears, so that the life of the combustor lining component can be diagnosed.

A new functional AlN ceramics sintered body having a voltage measuring circuit for life diagnosis was produced by the reaction sintering method by using the metal Al powder instead of the metal Si powder described above and applied to the combustor lining parts. did. As a result, the same result was obtained, and it was found that life diagnosis was possible.

Further, Si ₃ N ₄ and Si ₂ N are added to the above Si powder.
₂ O, AlN, Al ₂ O ₃ , ZrO ₂ , B ₄ C, BN, powders such as mullite, whiskers, etc. are mixed to form a new functional composite ceramics sintered body having a conductive circuit for voltage measurement for life diagnosis ( Si ₃ N ₄ / Si ₃ N ₄ , Si ₃ N ₄ / Si ₂ N ₂ O, Si ₃ N ₄ / A
1N, Si ₃ N ₄ / Al ₂ O ₃ , Si ₃ N ₄ / ZrO ₂ , Si ₃ N ₄ / B
₄ C, Si ₃ N ₄ / BN, Si ₃ N ₄ / Mullite, Si ₃ N ₄ / SiC
Etc.) were produced by the reaction sintering method and applied to combustor lining parts. As a result, the same result was obtained, and it was found that life diagnosis was possible.

The ceramics of the present invention can be molded according to various component shapes such as doctor blade, mold powder molding, CIP, injection molding, cast molding and extrusion molding.

The molding binder such as the green sheet is generally used as a binder for molding ceramics such as polymer materials such as polyvinyl butyral and polyethylene, silicone compounds and polysilane compounds. Things can be used. The degreasing method of these binders is not particularly limited, but degreasing can be performed by controlling the temperature rising rate during sintering.

Here, the following method can be considered as a method of forming the voltage measuring circuit. Possible by various methods such as a method of forming a circuit pattern on the surface of a ceramic molded body by an ink jet method using a slurry composed of fibers such as carbon and a medium, and a method of forming a circuit pattern by printing a slurry composed of fibers such as carbon and a medium. Is.

[Embodiment 8] New Functional Ceramics Structure Section
As a raw material for products, ZrO₂Powder: 50 parts by weight and SiO ₂Powder:
30 parts by weight, Al₂O₃Powder: 20 parts by weight of triethano
Amine: 1 part by weight, distilled water: 65 parts by weight, mixed
And used as raw material. For molten metal by casting this raw material
Make tundish, refractory for mold inlet, mold
It was C fiber bundles (diameter 100 μm,
Voltage measurement for life diagnosis using a length of 50 cm (1000 pieces)
It was formed as a constant conductive circuit.

The above-mentioned molded body was heated in an oxidizing atmosphere at a temperature rising rate of 5 ° C./min to 1650 ° C., held for 2 hours, and then allowed to cool in a furnace to burn a ceramic having a conductive circuit for measuring voltage for life diagnosis. I got a union. The degreasing of the binder, etc.
This is done in the process of raising the temperature. Then, the end of the conductive circuit for life diagnosis was wired to an external measuring device using copper wiring.
Also, the conductive circuit for life diagnosis was kept insulated by a SiC protective tube.

This ceramic structural part was applied to a continuous casting facility. As a result of the test, the ceramic structural parts are deteriorated and cracks are generated, and at the same time, the voltage is changed, and the change can be detected to inform the driver of the life of the parts. Thereby, the continuous casting equipment can be efficiently maintained.

Instead of the above ceramic powder, Si
C, Si ₂ N ₂ O, AlN, Al ₂ O ₃ , ZrO ₂ , B ₄ C, B
A new functional ceramics sintered body (Si ₃ N ₄ , which has a voltage measuring circuit for life diagnosis similarly using N, mullite powder, etc.)
Si ₂ N ₂ O, AlN, Al ₂ O ₃ , ZrO ₂ , B ₄ C, BN,
Mullite, Si ₃ N ₄ / SiC composite material, Al ₂ O ₃ / ZrO ₂ composite material, SiC / Al ₂ O ₃ composite material, Si ₃ N ₄ / ZrO ₂ composite material, S
i ₃ N ₄ / Al ₂ O ₃ composite material, Si ₃ N ₄ / BN composite material, mullite
/ SiC composite material, ZrO ₂ / BN composite material) were produced by an atmospheric pressure sintering method and applied to continuous casting equipment parts. Test results,
Similar changes in voltage appear, life diagnosis is possible, and maintenance is easy.

According to the present invention, the ceramic structural part of the ceramic or the ceramic sintered body itself is provided with the conductive circuit for generating the induced current for life diagnosis, and the life of the structural part is judged under the actual use condition to perform maintenance. The life diagnosis method to be determined improves the reliability of the ceramic structural parts, and can be easily applied to parts of various plants, structural parts such as engines and the like.

Then, an induced current is generated in a conductive circuit having one-dimensional or more orientation in the ceramics or ceramics sintered body, and a voltage change due to cracking, deformation, temperature, oxidation, etc. on the surface of the ceramics or ceramics sintered body. Since the reliability of ceramics or ceramic structural parts of ceramics sintered body can be improved by measuring, the first wall for fusion reactor, wear resistant wall for piping, corrosion resistant wall for piping, chemical resistant wall for piping, gas Turbine blade, gas turbine stationary blade, gas turbine nozzle, gas turbine shroud, combustor,
Ducts, heat exchangers, bearings, turbocharger rotors for automobile engines, refractory materials for molten metal, ladle for molten metal,
The reliability of ceramics or ceramics sintered bodies such as a tundish for molten metal, a mechanical seal ring, a chemical seal ring, a plunger, a sandblast nozzle, a welding tip cover, and a catalyst carrier can be remarkably improved.

Although the present invention has been described in detail with respect to the above-described embodiments, the present invention is not limited to these embodiments by the above, and various modifications can be made without departing from the spirit of the present invention. In addition, it goes without saying that various modifications can be made.

[0106]

EFFECTS OF THE INVENTION According to the method of predicting the life of ceramic structural parts of the first to fourth aspects of the present invention, it is possible to predict the life of a ceramic structural part that is actually operating, and to predict the life of a highly reliable ceramic structural part. A method can be provided. Furthermore, by arranging conductive circuits that generate an induced current in the ceramic structural component, the entire surface of the ceramic structural component can be detected, and the reliability of the method for predicting the life of the ceramic structural component is further increased. The method of predicting the life of a ceramic structural component can be applied to a ceramic structural component having a complicated shape. Further, by providing a conductive circuit containing conductive ceramics, carbon, metal or the like, a conductive circuit having a large skin effect can be provided by using a material of a general conductive circuit.

According to the maintenance / inspection method for ceramic structural parts of the fifth aspect of the present invention, destruction can be prevented in advance, and the reliability of ceramics is greatly improved by this maintenance / inspection method.

According to the method for diagnosing life of various plants of the sixth invention to the ninth invention, at least one of a plurality of structural parts constituting various plants is made of a ceramic sintered body, and the conductive circuit of the ceramic sintered body is used. Since the life of the ceramics sintered body is predicted based on the voltage change, the life can be monitored simply by installing it in the vicinity of the maximum stress and in the structural parts where wear occurs without providing a conductive circuit for all parts of the plant. I can. Since the skin effect is sufficiently generated on or near the surface of structural parts, when it is judged that maintenance is required by comparing the voltage fluctuation due to cracks generated on the surface with the set threshold value, the equipment is stopped and the structural parts Can be exchanged.

According to the ceramic structural parts of the tenth invention and the eleventh invention, carbon, ceramics, metal, or carbon fiber, ceramic fiber,
Since the conductive circuit constituted by at least one of the metal fibers is provided, the skin effect generated in this conductive circuit can be sufficiently exerted, and carbon, ceramics, metal, or carbon fiber, ceramic fiber, metal of this conductive circuit is provided. The fiber functions as a reinforcing material for the ceramic sintered body.

According to the ceramic structure component of the twelfth invention, in the tenth invention or the eleventh invention, the conductive circuit has a terminal electrically connected to an external circuit of the conductive circuit. In addition to the effects of the tenth invention or the eleventh invention, it becomes easy to electrically connect to the external power source of this conductive circuit.

According to the ceramic structural part of the thirteenth invention, in the tenth invention or the eleventh invention, the conductive circuit has a resistance value capable of being heated to a sufficient temperature for relaxing the thermal stress of the ceramic sintered body. Therefore, in addition to the effects of the tenth invention or the eleventh invention, it is possible to sufficiently heat the ceramics sintered body to relax the thermal stress from the outside. It is extremely effective in relaxing the stress when it occurs.

According to the ceramic structure component of the fourteenth invention, in the tenth invention or the eleventh invention, the conductive circuit has a relative permittivity of 30 or more or the conductive circuit has a magnetic permeability of 1 or more. In addition to the effects of the invention or the eleventh invention,
It is possible to bring about a sufficient skin effect of the ceramics sintered body.

According to the ceramic structural component of the fifteenth invention, in the tenth invention or the eleventh invention, the ceramic sintered body is an oxide, a nitride, a carbide, a carbonitride, an oxynitride, a boride, In addition to the effects of the tenth invention or the eleventh invention, the ceramic sintered body has a small dimensional change rate of 1% or less during sintering from a molded body to a sintered body, since it comprises at least one silicide. The conductive circuit for generating an induced current for life measurement oriented in the molded body is oriented in the ceramic sintered body without being deformed or cut, and no residual stress remains in the conductive circuit itself. Further, since the ceramic sintered body is porous, it becomes possible to coat or impregnate the surface or the inside with a substance satisfying the required characteristics when it is used for a structural part. Further, the surface of the ceramic sintered body can be made of a dense wear resistant material, heat resistant material, corrosion resistant material, or the like. The conductive circuit of SiC is effective for detecting surface cracks in heat resistant parts. Then, the rigidity can be increased more than that of the simple substance by compounding and strengthening the particle dispersion.

According to the ceramic structural component of the 16th aspect of the invention, the conductive circuit comprises C and / or Si, Ti, Zr, Cr,
This ceramic sintered body is a compact or a sintered body because it is a simple substance made of any one of W and Mo or at least one of nitride, carbide, carbonitride, boride, and silicide. The dimensional change rate at the time of sintering is as small as 1% or less, the conductive circuit provided therein is oriented in the ceramic sintered body without being deformed or cut, and no residual stress remains in the conductive circuit itself. Furthermore, since the ceramic sintered body is porous, when used for structural parts, it becomes possible to coat or impregnate the surface or inside with a substance that satisfies the required properties. Further, the surface of the ceramic sintered body can be made of a dense wear resistant material, heat resistant material, corrosion resistant material, or the like. The SiC conductive circuit is effective for detecting surface cracks in the heat resistant component.

According to the method for manufacturing a ceramic structural component of the seventeenth aspect of the present invention, it is possible to easily obtain a reinforced sintered ceramic sintered body at the same time.

According to the method for producing a ceramic structural part of the eighteenth aspect of the present invention, the metal powder reacts with the reactive gas to produce a product, and at the same time, the inorganic compound and the conductive circuit are bound by the product. Has a porosity of 5 to 30 vo
It is possible to manufacture a reaction-sintered ceramics sintered body in which a conductive circuit for generating an induction current of 1% is oriented.

According to the method for manufacturing a ceramic structural part of the nineteenth aspect of the present invention, it becomes possible to provide, as a conductive circuit, a conductive material for generating an induced current that cannot withstand the sintering temperature by the sintering process. .

[Brief description of drawings]

FIG. 1 is a sectional view illustrating a skin effect generated around a conductive circuit.

FIG. 2 is a cross-sectional view illustrating a skin effect generated around another conductive circuit.

FIG. 3 shows a voltage measuring circuit for monitoring the life of the first wall component of the fusion reactor, (A) is a principle diagram of the voltage measuring circuit, and (B) is a sectional view taken along line I-I of (A).

FIG. 4 is a relationship curve diagram between a neutron irradiation time and a voltage change rate of the first wall component of the fusion reactor.

FIG. 5 is a sectional view of a ceramics sintered body for life monitoring of the first wall component of the fusion reactor.

FIG. 6 shows another voltage measuring circuit for monitoring the life of the first wall component of the fusion reactor, (A) is a principle diagram of the voltage measuring circuit, and (B) is a sectional view taken along line II-II of (A). .

FIG. 7 shows a voltage measuring circuit for life monitoring of a gas turbine stationary blade component, (A) is a principle view of the voltage measuring circuit, and (B) is a sectional view taken along line III-III of (A).

FIG. 8 is a relationship curve diagram between a gas turbine operating time and a voltage change rate.

FIG. 9 is a principle diagram showing a voltage measuring circuit for monitoring the life of corrosion-resistant pipe parts.

FIG. 10 is a relationship curve diagram between chemical (alkali, acid) corrosion time and voltage change rate.

FIG. 11 is a cross-sectional view showing an example of installation of a conductive circuit for a pipe-shaped component.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ceramic matrix (ceramic structural component) 2 Sample 3 Conductive circuit 5 High frequency power supply 6 Voltage change measuring instrument 8 Coating layer 10 Crack 12 Sample surface 14 Skin effect 15 Surface layer 17 Terminal 18 Nuclear power plant system 19 Thermal power plant system 20 Chemical plant system

Claims (19)

[Claims] 1. A ceramic structure characterized in that a conductive circuit is provided on or near the surface of the ceramic structural component, an induced current is passed through the conductive circuit, and the life of the ceramic structural component is predicted based on the voltage change. How to predict the life of parts. 2. A ceramic circuit is provided with a conductive circuit having conductive ceramics on or near the surface thereof, an induced current is passed through the conductive circuit, and the life of the ceramic structural part is predicted based on the voltage change. A method for predicting the life of ceramic structural parts. 3. A ceramic structural part is provided with a conductive circuit having carbon on or near the surface thereof, an induced current is passed through the conductive circuit, and the life of the ceramic structural part is predicted based on the voltage change. Life prediction method for ceramic structural parts. 4. A ceramic structure part is provided with a conductive circuit having a metal on or near the surface, an induced current is passed through the conductive circuit, and the life of the ceramic structure part is predicted based on the voltage change. Life prediction method for ceramic structural parts. 5. A ceramic structure part is provided with a conductive circuit on or near the surface thereof, an induced current is passed through the conductive circuit, the voltage change thereof is measured, and the change amount of the voltage change and the ceramic structure part previously obtained. And a threshold value represented by a voltage change amount indicating the life of the ceramic structure component, and when the change amount of the voltage change reaches the threshold value, maintenance and inspection of the ceramic structural component are performed. How to maintain and inspect structural parts. 6. In a gas turbine for rotating a turbine by combustion gas, at least one of a plurality of structural parts constituting the gas turbine is made of a ceramics sintered body, and a conductive circuit is provided on or near the surface of the ceramics sintered body. Is provided, an induction current is caused to flow through the conductive circuit, and the life of the ceramics sintered body is monitored based on the voltage change thereof. 7. In a nuclear power plant using energy generated by nuclear fission, at least one of a plurality of structural parts constituting the nuclear power plant is made of a ceramics sintered body, and the ceramics sintered body is provided on or near the surface thereof. A life diagnostic method for a nuclear power plant, comprising providing a conductive circuit, flowing an induced current in the conductive circuit, and monitoring the life of the ceramic sintered body based on a voltage change thereof. 8. In a nuclear fusion plant that generates energy by nuclear fusion, a ceramic sintered body is provided on the side of at least one plasma facing a plurality of structural parts constituting the nuclear fusion plant, and the ceramic sintered body is provided. A method for diagnosing the life of a nuclear fusion plant, characterized in that a conductive circuit is provided on the surface of or near the surface, an induced current is passed through the conductive circuit, and the life of the ceramic sintered body is monitored based on the voltage change. 9. In a magnetohydrodynamic power plant that generates electrical energy by high-temperature gas plasma flowing at high speed across a magnetic field, a hot gas exhaust duct inner wall constituting the magnetohydrodynamic power plant is made of a ceramic sintered body, A magnetohydrodynamic power plant characterized in that a conductive circuit is provided on or near the surface of the ceramic sintered body, an induced current is passed through the conductive circuit, and the life of the ceramic sintered body is monitored based on the voltage change. Life diagnosis method. 10. A ceramic structural component having a ceramics sintered body, wherein at least one of carbon, ceramics, and metal is provided on or near the surface of the ceramics sintered body.
A ceramic structural part characterized by comprising a conductive circuit for generating an induced current, which is composed of two parts. 11. A ceramic structural part having a ceramics sintered body, wherein a conductive circuit for generating an induced current is formed on the surface of the ceramics sintered body or in the vicinity thereof by at least one of carbon fiber, ceramics fiber and metal fiber. A ceramic structural part characterized by being provided with. 12. The ceramic structural component according to claim 10 or 11, wherein the conductive circuit has a terminal electrically connected to an external circuit of the conductive circuit. 13. The ceramic structural component according to claim 10, wherein the conductive circuit has a resistance value capable of being heated to a temperature sufficient to relieve the thermal stress of the ceramic sintered body. 14. The ceramic structural component according to claim 10, wherein the conductive circuit has a relative permittivity of 30 or more, or the conductive circuit has a magnetic permeability of 1 or more. 15. The ceramic sintered body according to claim 10 or 11, comprising at least one of oxide, nitride, carbide, carbonitride, oxynitride, boride, and silicide. Ceramic structural parts characterized by: 16. A ceramic structural part having a ceramics sintered body, wherein a conductive circuit is provided on or near the surface of the ceramics sintered body, and the conductive circuit comprises C and / or
Alternatively, it is characterized in that it is made of any one of Si, Ti, Zr, Cr, W, and Mo, or at least one of nitride, carbide, carbonitride, boride, and silicide. Ceramic structure parts. 17. A molded body having the ceramic powder is provided on the surface or in the vicinity of the molded body with a composition for forming a conductive circuit for generating an induced current, the composition comprising carbon fibers and / or conductive ceramics, and the molded body and the composition for forming. 1. A method for manufacturing a ceramic structural part, which comprises simultaneously sintering objects. 18. A composition for forming a conductive circuit for generating an induced current, comprising carbon fibers and / or conductive ceramics, is provided on or near the surface of a molded product containing a metal powder, and the molded product and the forming composition are provided. 1. A method for manufacturing a ceramic structural part, which comprises simultaneously sintering an object in a nitriding, carbonizing, carbonitriding gas atmosphere. 19. A method for manufacturing a ceramic structural component, characterized in that a conductive circuit for generating an induced current made of carbon fibers and / or conductive ceramics is provided on or near the surface of a sintered ceramics body after sintering. .