JP2684427B2 - Composite ceramic structure - Google Patents

Description

TECHNICAL FIELD The present invention relates to a composite ceramic structure, and particularly to a porous composite ceramic having high strength.

[Conventional technology]

In general, SiC and Si ₃ N ₄ having excellent heat resistance are known as engineering ceramics suitable for structural materials such as engines and turbines. However, SiC and Si ₃ N ₄
Is a compound having a strong covalent bond, so that it is difficult to sinter by itself, and a sintering aid is required to obtain a sintered body.

For example, when Si ₃ N ₄ is pressure-sintered, Y ₂ O ₃ , Al ₂ O ₃
It is known that a high-density sintered body can be obtained by adding. However, since the glass phase formed by these sintering aids is softened at high temperature, the mechanical properties of the sintered body at high temperature are significantly deteriorated. In order to prevent this decrease in strength at high temperatures, studies have been conducted to reduce the amount of sintering aid as much as possible, and to crystallize the glass phase of the grain boundary caused by the sintering aid. It has not been resolved.

On the other hand, a fiber reinforced method for increasing high temperature strength by compounding with whiskers such as SiC and Si ₃ N ₄ is also considered (ceramics society academic journal, 91, [11], 1983, P491). Since a sintering aid is used, the mechanical properties of the sintered body at high temperatures are significantly reduced.

As a method of sintering a ceramics composite composed of two or more kinds of inorganic compounds having different characteristics without using a sintering aid, a method using a reaction bonding method is known (for example, Japanese Patent Laid-Open No. 61- No. 101465). However, since this conventional material uses particles having an average particle size of metallic Si of 0.5 μm or more, the space of the SiC particles is bonded by a relatively large Si-based nitride and the maximum pore size is 30 μm or more. Only a sintered body having a large pore shape has been studied. For this reason, there is a limit to the increase in strength. Moreover, the method of supplying Si-based nitride from a gas source has not been studied. Up to now, in a ceramic composite composed of two or more kinds of inorganic compounds, the condition for bonding with high strength is unknown, and high strength porous ceramics have not been obtained.

[Problems to be solved by the invention]

An object of the present invention is to provide a composite ceramic structure,
The inorganic compound is strongly bonded with a Si-based nitride having an average particle size of 0.2 μm or less and / or the maximum pore size is 10 μm or less,
By providing a sintered body having a porosity of 5 to 40 vol%, it is an object to provide an unprecedented high-strength porous composite ceramic structure.

[Means for solving the problem]

In order to achieve the above object, in the present invention, A element and B
Inorganic compound AB whose electronegativity scale difference is 1.7 or less
Particles and / or whiskers of at least one of carbides, nitrides and oxides having an average particle size of 0.2 μm
A composite ceramic structure characterized by being a sintered body having the following porosities of 5 to 40 vol% and composed of Si-based nitrides, or electronegativity of A element and B element The difference in scale of the inorganic compound AB is 1.7 or less, particles of at least one of carbides, nitrides and oxides and / or whiskers are particles of Si-based nitride, and the maximum pore size is 10 μm. Porosity below 5
To 40 vol% of a sintered body, or a carbide which is an inorganic compound AB having a scale difference of electronegativity between A element and B element of 1.7 or less, nitriding Of particles and / or whiskers of oxides and oxides having an average particle size of 0.2 μm or less
The maximum pore size of particles that are made of a system nitride and are bonded to each other.
A composite ceramic structure characterized by being a sintered body having a porosity of 5 to 40 vol% of 10 μm or less.

In order to achieve another object, in the present invention, particles of at least one inorganic compound of carbide, nitride and oxide and / or whiskers are a measure of electronegativity formed on the surface of the inorganic compound. The difference is that the particles are made of Si-based nitride having an average particle size of 0.2 μm or less, with an inorganic compound layer made of elements having a difference of 1.7 or less interposed between them, and the sintered bodies have a porosity of 5 to 40 vol%. A composite ceramic structure characterized by, or, at least one kind of inorganic compound particles of carbide, nitride and oxide and / or whiskers, the scale difference of the electronegativity formed on the surface of the inorganic compound, A composite characterized by being a sintered body having a maximum porosity of 10 μm or less and a porosity of 5 to 40 vol%, which are bonded to each other by particles of Si-based nitride with an inorganic compound layer composed of an element of 1.7 or less interposed therebetween. ceramic Structure, or at least one kind of inorganic compound particles and / or whiskers of carbide, nitride and oxide, the electronegativity scale difference formed on the surface of the inorganic compound, the element of 1.7 or less An average particle size of 0.2
A composite ceramic structure characterized in that it is a sintered body having particles having a maximum pore diameter of 10 μm or less and having a porosity of 5 to 40 vol%, which are particles of Si-based nitride having a diameter of μm or less.

In the present invention, the electronegativity of the A element and the B element is adjusted by setting the average particle diameter of metallic Si used as a raw material to 0.3 μm or less, or by supplying the Si-based nitride from the gas source instead of the raw material. Inorganic compound AB with a scale difference of 1.7 or less
The surface of an inorganic compound such as a carbide, a nitride, an oxide, or an oxynitride is firmly bonded with particles or whiskers made of a Si-based nitride having an average particle size of 0.2 μm or less, and the strength can be increased. Is. As a result, it was possible to obtain a high-strength porous composite ceramic structure that has never been obtained.

 Next, the present invention will be described in detail.

The average particle size of the Si-based nitride that binds the inorganic compound is 0.2
The reason why the particle size is less than or equal to μm is that by using a Si-based nitride having an average particle size of less than or equal to 0.2 μm for binding the inorganic compound, it is possible to obtain a uniform distribution state in which the pore size between particles is less than or equal to several μm. It was found that the mechanical strength was significantly improved.

FIG. 1 shows Si _{3 having a} constant porosity of 10 vol% obtained in Example 38.
The relationship between the average grain size of Si-based nitrides and bending strength in N ₄ / SiC sintered bodies is shown. From this, it was found that when the average particle size of Si ₃ N ₄ was 0.2 μm, the strength sharply improved and nearly doubled. This is because if the average particle diameter is larger than 0.2 μm, the pore diameter becomes large, and the maximum pore diameter becomes the starting point of fracture, resulting in a decrease in strength. FIG. 2 shows the relationship between the maximum porosity and the bending strength of the Si ₃ N ₄ / TiN sintered body obtained in Example 39 and having a constant porosity of 20 vol%. From this, it was found that the strength rapidly increased when the maximum pore diameter was 10 μm or less, and was almost doubled. This is because the maximum pore size is the starting point of fracture. Therefore, it is extremely important to set the maximum pore diameter to 10 μm or less, and for that reason, it is necessary to set the average particle diameter of the Si-based nitride as the binder to 0.2 μm or less.

In the present invention, in order to make the average particle diameter of the Si-based nitride binding the inorganic compound 0.2 μm or less and the maximum pore diameter 10 μm or less, for example, a metal mixed with the inorganic compound is used.
The average grain size of Si powder is 0.3μm or less, and the crystal temperature is 1250.
It can be achieved by setting the temperature to ° C. As the metal Si powder, one having a surface formed with a film of hydroxide or the like may be used.

Further, a molded body made of the inorganic compound or a metal Si powder having an average particle size of 0.3 μm or less is used as
It can also be obtained by heating in an atmosphere containing, for example, an atmosphere of ammonia and silane gas. It can also be obtained by epitaxially growing an amorphous Si-based nitride and then crystallizing it by heat treatment. It can also be obtained by heating a compact made of a Si-based nitride having an average particle diameter of 0.2 μm or less, which serves as the inorganic compound and a binder, in an atmosphere containing Si and N.

In the present invention, the Si-based nitride that binds the inorganic compound is preferably a Si-based nitride produced by epitaxial growth. This is because most of the particles have a size of 0.1 μm or less, and if they are small, particles of the order of several nm can be obtained, and the pore diameter can be made small and uniform. The particles and whiskers grown epitaxially are centered on the Si-based nitride phase, and preferably the Si-based nitride content is 70 vol% or more. This is because when a large amount of oxynitride phase is generated, the binding force with the inorganic compound is reduced.

In the present invention, the reason why the inorganic compound AB has an electronegativity scale difference of 1.7 or less between the element A and the element B is that the electronegativity scale difference of each element is L. Pauling (L. Pauling). ), The scale difference of electronegativity is larger than 1.7, that is, in an inorganic compound having a strong ionic bond degree, particles or whiskers made of Si-based nitride are difficult to epitaxially grow on the surface of the inorganic compound, and thus the bond is formed. This is because it was found by experiments by the inventors that the strength was small.

Here, the electronegativity refers to the ability to attract electrons when atoms form a chemical bond, and is a value calculated and defined by the following formula by Elle and Pauling.

Δ _AB = D _AB − (1/2) (D _AB + D _BB ) where, D: binding energy, and inorganic compounds with electronegativity scale difference of 1.7 or less, especially Si, Ti, Zr, Cr, Al and Mo nitrides and carbides are preferred because of their high bonding strength. The electronegativity values determined by Elle and Pauling are shown in Table 1. In the method of bonding an inorganic compound with a Si-based nitride by using a sintering aid, a shrinkage from a compact to a sintered body causes a large deformation and the like, and a liquid phase that softens at a high temperature in the sintered body ( (Alloy phase) remains and causes a decrease in strength, whereas in the present invention, at least one of an inorganic compound having a scale difference of electronegativity of 1.7 or less is crystalline, The particles made of Si-based nitride, or particles and whiskers that combine with each other by epitaxial growth do not have a liquid phase part that softens at high temperature, so there is no strength decrease at high temperature and dimensional shrinkage during sintering. It can be sintered with almost nothing.

In the present invention, the reason why the inorganic compound is a carbide, nitride, or oxide having a scale difference of electronegativity between the A element and the B element of 1.7 or less is that boride, silicon oxide reacts with Si-based nitride. Therefore, it is difficult to reduce the average particle size to 0.2 μm or less.

For inorganic compounds with a scale difference of electronegativity larger than 1.7, the inorganic compound is oxidized or nitrided to form a film with a scale difference of electronegativity of 1.7 or less on the surface of the inorganic compound. , Particles made of crystalline Si-based nitride, or particles and whiskers can be bonded to each other by epitaxial growth.

As shown in FIG. 10, the crossing angle difference θ between the lattice of the inorganic compound and the Si-based nitride epitaxially grown is preferably 70 degrees or less. This is because if it exceeds 70 degrees, the shearing and tensile strengths between the particles are reduced and the mechanical strength is reduced.

In the present invention, the reason why the porosity is 5 to 40% is as follows.
This is because when the porosity exceeds 40%, the strength rapidly decreases. Further, it is difficult to reduce the porosity to less than 5% for epitaxial growth by the vapor phase reaction. This is because the pores through which the gas passes are necessary. However, after completing the epitaxial growth process, HP, HI
It is also possible to make it denser by P. As a result, a dense sintered body having no glass layer at the grain boundaries can be obtained. As the inorganic compound, particles having an average particle size of 20 μm or less and / or whiskers having an aspect ratio of 100 or less and a length of 100 μm or less are preferably used. This is because when the average particle size exceeds 20 μm, the aspect ratio exceeds 100, and the length exceeds 100 μm, it is difficult to mix and the dispersed state is not good, so the maximum pore size is
This is because it is difficult to reduce the thickness to 10 μm or less. As the inorganic compound, a commercially available product can be used as it is. Alternatively, rounded particles crushed by a mill may be used. In particular, round particles have more uniform pores in the sintered body and have higher strength.

Raw material inorganic compound content in the sintered body is 5 to 80 vol%
It is preferable to set it in the range. This is because when the content is more than 80 vol%, the amount of bonding due to the epitaxial growth of the Si-based nitride decreases and the mechanical properties of the ceramic sintered body deteriorate. On the other hand, if it is less than 5 vol%, the effect of preventing the crack growth due to the inorganic compound particles cannot be obtained, so that the mechanical strength is lowered.

Further, a method for epitaxially growing a crystalline Si-based nitride on the surface of the inorganic compound is such that a molded body made of the inorganic compound exists in an atmosphere containing Si and N, and
If the potential energy of the inorganic compound is low with respect to the reaction between Si and N, Si-based nitride grows and stacks on the surface and bonds between the particles. It can also be obtained by epitaxially growing an amorphous Si-based nitride and then crystallizing it by heat treatment. Methods such as molecular beam are also effective.

Resin, particles, oil,
It is also possible to impregnate a solid lubricant or the like. By impregnating uniform small pores with the above substance, a sliding material having a low coefficient of friction can be obtained.

As the molding method, various molding methods such as injection molding, press molding, casting molding, rubber press molding, extrusion molding, and die powder molding are selected according to the shape and required characteristics. It is also possible to take out the fine-grained Si raw material in the glow box, mold it, and sinter it.

It is also possible to obtain various properties by adjusting the type of the inorganic compound and the compounding ratio of Si-based nitride. For example, when a conductive inorganic compound is used, a ceramic composite having conductivity can be obtained. Depending on the type and blending ratio of inorganic compounds, the electrical resistivity will be in the order of 10 ^-7 Ωm to 10 ¹⁵ Ωm.
A ceramic composite having characteristics of the order is obtained.

(Operation)

The average particle size of at least one of carbide, nitride and oxide, which are inorganic compounds with electronegativity scale difference of 1.7 or less.
A high-strength porous composite ceramic structure can be obtained by firmly bonding each other with particles or whiskers of Si-based nitride of 0.2 μm or less to obtain a sintered body having a maximum pore diameter of 10 μm or less.

〔Example〕

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples.

Example 1 SiC particles having an average particle size of 5 μm (scale difference of electronegativity: 0.
7) Polyvinyl alcohol (PV
2 parts by weight of A) were added and mixed to prepare a test raw material. Material is mechanically pressed using a molding pressure of 100 kgf / cm ² and a diameter of 50 m
It was molded to have a thickness of m and a thickness of 20 mm. The degreased body obtained by removing the molding binder from this molded body was installed in the core of a ring furnace with a diameter of 50 mm in such a manner as to block the inside of the furnace, and a mixed gas of SiH ₄ and NH ₃ was made to flow at 1300 ° C for a long time Heated. From this, Si
A sintered body was obtained in which Si ₃ N ₄ whiskers / particles were epitaxially grown on C particles. The composition ratio of the obtained sintered body was SiC: Si ₃ N ₄
It was 45:55 vol%.

An example of observing the process of epitaxial growth of Si ₃ N ₄ whiskers and particles on SiC particles with a scanning electron microscope (SEM) is shown in FIGS. 3 and 4. This allows S on the SiC particles.
It can be clearly seen that i ₃ N ₄ whiskers and particles are epitaxially grown.

FIG. 5 shows an example of dense epitaxial growth of Si ₃ N ₄ particles on the surface of SiC particles. From this, Si ₃ N ₄ particles are 0.2μ
It can be seen that it is composed of fine particles of m or less.

An example of the SEM image of the finally obtained sintered body is shown in FIG. From this, it is understood that the surroundings of the SiC particles are bonded by the epitaxially grown Si ₃ N ₄ whiskers / particles, and the maximum pore diameter is 10 μm or less.

An example of observing the vicinity of the grain boundary with a transmission electron microscope (TEM) is shown in FIG. The lattice crossing angle between SiC particles and Si ₃ N ₄ is approximately
It is 25 degrees. As a result of examining this grain boundary by energy dispersive X-ray analysis, it was confirmed that inclusions such as oxygen were not present. From this, it is understood that in the product of the present invention, SiC particles are bonded by epitaxially grown Si ₃ N ₄ whiskers / particles. The bending strength of the obtained sintered body at 1200 ° C is
480MPa, Weibull coefficient was 18.3, and a good and reliable sintered body was obtained.

Next, for comparison, Si ₃ N ₄ 62 vol%, SiC ₃ vol%, Al ₂ O ₃
A mixed powder having a composition of ₃ vol% and Y ₂ O _{3 5} vol% was prepared. This was molded in the same manner as above and hot-press sintered at 1700 ° C. for 3 hours at 29 MPa to obtain a sintered body.

The STEM image of the obtained sintered body is shown in FIG. The results of energy dispersive X-ray spectroscopy (EDX) analysis are shown in FIG.
From this, Si ₃ N ₄ and SiC are bonded in the glass phase containing Al ₂ O ₃ and Y ₂ O ₃ in the grain boundary portion, and the present invention is not bonded in Si ₃ N ₄ particles. It turns out to be different. The bending strength at 1200 ° C. of the obtained sintered body was 180 MPa, and the Weibull coefficient was 7.3, so that only a sintered body with low reliability was obtained.

Examples 2 to 29 In the same manner as in Example 1, in place of the SiC particles, an inorganic compound having an average particle size of 2 μm shown in Table 2 was added, and molding was performed in the same manner.
Sintered. As a result, S with an average particle size of 0.2 μm or less
A sintered body having a maximum pore diameter of 10 μm or less, which was bonded by i ₃ N ₄ particles, was obtained. Also, for the sintered body, on the inorganic compound particles
Whether Si ₃ N ₄ particles or Si ₃ N ₄ whiskers and particles are grown epitaxially SEM and TEM as in Example 1.
Confirmed by

The results are shown in Table 2 for Examples 2 to 25. For comparison, inorganic compounds having electronegativity scale values of more than 1.7 are shown in Examples 26 to 29. It was confirmed that the Si ₃ N ₄ whiskers / particles were not epitaxially grown in the inorganic compound having an electronegativity difference of more than 1.7.

Examples 30 to 37 TiN particles having an average particle size of 2 μm (scale difference of electronegativity: 1.
5) and 10 parts by weight of a polyethylene-based binder as a molding binder were added to and mixed with metal Si powder having an average particle size of 0.05 μm with a narrow particle size distribution to prepare a test raw material. 50 mm diameter and 20 mm thickness at a molding pressure of 1000 kgf / cm ² using a mechanical press
It was molded into one. The degreased body from which the molding binder had been removed was heated in an atmosphere of NH ₃ at 1350 ° C. for a long time.

As a result, a sintered body was obtained in which Si ₃ N ₄ particles were epitaxially grown on the TiN particles. Table 3 shows the relationship between the amount of TiN powder and the properties. From this, when the TiN amount is less than 5 vol%, there is no effect of preventing crack growth, so the strength decreases and the Weibull coefficient also decreases, making it impossible to obtain a reliable and good sintered body. Further, it can be seen that when the TiN amount is more than 80 vol%, the Si ₃ N ₄ particles that grow epitaxially do not bond sufficiently, so that only a sintered body with low strength can be obtained and the Weibull coefficient becomes small. From the above, the TiN amount was set to 5
It can be seen that the Weibull coefficient is particularly large and the reliability is high in the range from 80 vol% to 80 vol%.

Example 38 SiC particles having an average particle size of 2 μm (scale difference of electronegativity: 0.
7) and various metal Si powders having an average particle size of 0.02 μm to 5 μm were added and mixed with 9 parts by weight of a polyethylene-based binder as a molding binder to prepare a test raw material. 50 mm diameter and 20 mm thickness at a molding pressure of 1000 kgf / cm ² using a mechanical press
It was molded into one. The degreased body from which the molding binder in this molded body was removed was heated at 1350 ° C. for a long time in an N ₂ atmosphere.

As a result, sintered bodies having different Si ₃ N ₄ average particle diameters obtained by epitaxially growing Si ₃ N ₄ particles on SiC particles were obtained. First
The figure shows the relationship between the average particle size of Si ₃ N ₄ and bending strength. As a result, it can be seen that the average particle size of Si ₃ N ₄ is 0.2 μm and the strength is rapidly improved, and is nearly doubled. This is because if the average particle size of the Si powder is larger than 0.2 μm, the pore size becomes large, and the maximum pore size becomes the starting point of fracture, resulting in a decrease in strength.

Example 39 TiN particles having an average particle size of 3 μm (scale difference of electronegativity: 1.
5) and 9 parts by weight of a polyethylene-based binder as a molding binder were added to and mixed with various metal Si powders having an average particle diameter of 0.02 μm to 3 μm to prepare test materials. 50 mm diameter and 20 mm thickness at a molding pressure of 1000 kgf / cm ² using a mechanical press
It was molded into one. The degreased body from which the molding binder was removed was heated in an N ₂ + H ₂ atmosphere at 1350 ° C. for a long time.

As a result, sintered bodies having different maximum pore diameters, in which Si ₃ N ₄ particles were epitaxially grown on TiN particles, were obtained. In FIG.
The relationship between the maximum pore size and bending strength is shown. From this, it was found that the strength rapidly increased when the maximum pore diameter was 10 μm or less and nearly doubled. This is because the maximum pore system is the starting point of fracture. Therefore, the maximum pore size is 10μ
It means that it is extremely important to be less than or equal to m.

Example 10 TiO ₂ particles having an average particle diameter of 2 μm (scale difference of electronegativity: 2.
0) under nitrogen, for 1 h at 1700 ° C., T to TiO ₂ particle surface
After forming an iN film (scale difference of electronegativity: 1.5) to about 100 Å, a polystyrene binder was added together with metal Si powder having an average particle size of 0.05 μm at a compounding ratio of TiO ₂ : Si = 30: 70 wt%. 8 parts by weight were added and mixed to obtain a test raw material. Material is mechanically pressed using a molding pressure of 1000 kgf / cm ² with a diameter of 50 m
It was molded to have a thickness of m and a thickness of 20 mm. The degreased body from which the molding binder had been removed was heated in an NH ₃ atmosphere at 1400 ° C. for a long time.

As a result, a sintered body was obtained in which Si ₃ N ₄ particles were epitaxially grown on the TiN film on the surface of the TiO ₂ particles. The bending strength of the obtained sintered body was 400 MPa, and the Weibull coefficient was 18.8, which was a reliable and good sintered body.

Examples 41 to 45 In the same manner as in Example 1, instead of the SiC powder, an inorganic compound having an average particle size of 2 μm shown in Table 4 was added, and molding was performed in the same manner.
Sintered. As a result, S with an average particle size of 0.2 μm or less
A sintered body having a maximum pore diameter of 10 μm or less, which was bonded by i ₃ N ₄ particles, was obtained. Further, it was confirmed that the sintered body had a wide range of electrical resistivity from insulating property to conductive property.

[Effects of the Invention] In the present invention, the average difference in the electronegativity between the inorganic compound particles having a scale difference of 1.7 or less and / or whiskers is 0.2 μm.
The strength of the porous ceramics was improved because they were strongly bonded with Si-based nitrides of m or less, and materials having various properties were obtained. This will expand the application range of ceramics to fields such as structural parts such as engines, turbines and sliding agents, as well as aviation, space, steel and marine development.

[Brief description of the drawings]

Fig. 1 is a graph showing the relationship between the average grain size of Si-based nitrides and bending strength, Fig. 2 is a graph showing the relationship between the maximum pore size and bending strength, and Figs. 3 and 4 are on SiC particles. Si ₃ N ₄ whiskers / grain structure photograph of the process of epitaxial growth of particles observed by scanning electron microscope (SEM), Fig. 5 is a SEM grain structure photograph of dense Si ₃ N ₄ grains epitaxially grown on the surface of SiC particles, FIG. 6 is a photograph of an SEM grain structure showing Si ₃ N ₄ grains being epitaxially grown around the SiC grains. FIG. 7 is a TEM crystal structure photograph showing that Si ₃ N ₄ particles are epitaxially grown on the SiC particles. FIG. 8 is a STEM particle structure photograph of a Si ₃ N ₄ / SiC composite material as a comparative example. FIG. 9 is an X-ray photograph of the Si ₃ N ₄ / SiC grain boundary portion in FIG.
FIG. 10 is a schematic diagram showing a lattice intersection angle between an inorganic compound and a crystalline Si-based nitride.

Continuation of front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location C04B 35/80 A (72) Inventor Akio Chiba 4026 Kujicho, Hitachi City, Ibaraki Hitachi Research Laboratory, Hitachi, Ltd. ( 56) References JP 62-21769 (JP, A) JP 2-44078 (JP, A)

Claims (6)

(57) [Claims] 1. A scale difference in electronegativity between the A element and the B element is 1.
Particles and / or whiskers of at least one of carbides, nitrides and oxides, which are inorganic compounds AB of 7 or less, and particles of Si-based nitride having an average particle size of 0.2 μm or less, which are bonded to each other. A composite ceramic structure characterized by the following. 2. The difference in scale of electronegativity between element A and element B is 1.
Particles of at least one of carbides, nitrides and oxides, which are inorganic compounds AB of 7 or less, and / or whiskers are particles of Si-based nitride, which are bonded to each other and have a maximum pore diameter of 10 μm or less. A composite ceramic structure characterized by: 3. The electronegativity scale difference between the A element and the B element is 1.
Particles of at least one of carbides, nitrides and oxides which are inorganic compounds AB of 7 or less and / or whiskers are particles of Si-based nitride having an average particle size of 0.2 μm or less, and are bonded together to form a maximum gas. Porosity less than 10μm 5
To 40 vol% of a sintered body, a composite ceramic structure. 4. The inorganic compound according to any one of claims 1 to 3, wherein the inorganic compound is a particle made of a crystalline Si-based nitride epitaxially grown from the surface of the inorganic compound and bonded to each other. Composite ceramic structure. 5. The scale difference in electronegativity between element A and element B is 1.
A molded body comprising at least one kind of particles and / or whiskers of a carbide, a nitride and an oxide which is an inorganic compound AB of 7 or less, and a metal Si powder having an average particle size of 0.3 μm or less,
By sintering in a nitriding atmosphere, particles of Si-based nitride having an average particle diameter of 0.2 μm or less are grown on the surface of the inorganic compound, and pores having a maximum pore diameter of 10 μm or less that bond the inorganic compounds to each other. A method for producing a composite ceramic structure, characterized in that the sintered body has a rate of 5 to 40 vol%. 6. An inorganic compound layer and / or whiskers of at least one kind of carbide, nitride and oxide, on the surface of which an inorganic compound layer having an electronegativity difference of 1.7 or less is formed, and an average particle size. A compact made of metal Si powder having a particle size of 0.3 μm or less is sintered in a nitriding atmosphere to grow Si-based nitride particles having an average particle size of 0.2 μm or less on the surface of the inorganic compound. Porosity of 5 to 40 vol with maximum pore diameter of less than 10 μm, where inorganic compounds are bonded to each other
% Of a sintered body, a method for producing a composite ceramic structure.