JPS609982B2 - Manufacturing method for ceramic sintered bodies - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a sintered body of heat-resistant ceramics.

More specifically, the present invention involves mixing polytitanocarbosilane as a known heat-resistant ceramic additive, molding the mixture,
Simultaneously with or after the forming, the heat-resistant ceramic sintered body is heated and sintered in a vacuum or in an atmosphere consisting of at least one selected from inert gas, reducing gas, and hydrocarbon gas. It is related to the manufacturing method.

Conventionally, sintered bodies that have been used in many ways as ceramics with excellent heat resistance include, for example, Yama 203 and B4.
Oxides such as 0, Mg0, Zr02, Si02, SIC
, TIC, WC "Carbide such as B4C" Si3N4
Nitrides such as BN and AIN, shelving materials such as Ti&, Zr&, silicides such as MoSi2, WSj2, CrSi2, and composite compounds thereof are known. It has been produced by molding powder and sintering at extremely high temperatures.Recently, there has been much research into producing high-density sintered bodies with fewer pores using relatively low pressure and sintering temperatures. .

That is, by using the appropriate additives, the self-sintering properties of the ceramic can be improved, and at the same time, abnormal growth of the grains of the sintered body can be suppressed to prevent pores from remaining between the grains. This is because the grain boundaries can be filled with high density by the additives, so that it is possible to economically obtain high-density compacts. Conventionally used additives include, for example, Mg0 and Ni○ for N203, and C for Zr02.
a0 and Ti02, AI203 and Y20 for Si3N4
3, B, Sj, and C for SIC, and Ni and W for TIC.
C, Zr02 and CrB2 are used as additives for ZrB2, and most of them are oxide-based additives, but other additives are added as single metal elements, and for example, other additives are used for carbides. Other shelving materials are often added to carbides and shelving materials. The reason these additives are selected is that they cause a phase reaction between the base ceramic and the additive to assist in the firing of ceramics with poor self-sintering properties, or that the additive becomes plastic at high temperatures. This is because sintering progresses more easily as the additives turn into a liquid phase or turn into a liquid phase.However, the conventional additives mentioned above have the following drawbacks:Using a solid phase reaction between the additive and the ceramic matrix In high-density sintered bodies, second and third phases appear due to the reaction between additives and ceramics, and these are mainly present at grain boundaries. ``At high temperatures, plastic deformation occurs from these grain boundary components. In many cases, it is difficult to produce a sintered body that aims for high-temperature strength. For example, Si
When Mza0 is added to 3N4, SiM is added as the second phase.
A glassy phase called g03 is formed and this fills the grain boundaries, achieving high density. However, the mechanical strength of this sintered body at high temperatures is
It has the disadvantage that it rapidly decreases from around 00oC. Furthermore, high-density sintered bodies that utilize plasticization and liquid phase formation of additives also have the disadvantage of a significant decrease in strength due to plastic deformation and liquid flow at grain boundaries at high temperatures, as described above. On the other hand, as additives that do not cause the above-mentioned reduction in high-temperature strength, it is promising to use additives that exclude oxides that tend to become glassy or simple metals that tend to turn into a liquid phase. In general, since self-sintering properties and shelving properties are poor, sufficient densification effects cannot be expected even if they are used as additives.The present invention does not cause plastic deformation at high temperatures, and furthermore, By using a new additive that has the properties of densely filling the grain boundaries in the process, improving the crystallization properties of the base ceramic, and inhibiting the growth of coarse grains in the ceramic, it is possible to improve the conventional ceramic sintered compact. The purpose of the present invention is to provide a method for manufacturing a heat-resistant ceramic body having excellent mechanical strength at room temperature and high temperature, which is equal to or higher than that of conventional ceramic body formed bodies, despite having a lower density. It is something to do.

Next, the organometallic copolymer used in the present invention and its manufacturing method are disclosed in Japanese Patent Application No. 54-8079 filed by the present inventor.
Although it is disclosed in detail in the two-word specification, it can be summarized as follows.

That is, the organometallic copolymer described above has {1) a main chain skeleton mainly composed of structural units of the formula Si-CH2, with a number average molecular weight of about 500 to 10,000, in which silicon atoms are substantially (1) a polycarbosilane having two side chain groups selected from the group consisting of a hydrogen atom, a lower alkyl group (preferably 1 to 4 carbon atoms), and a phenyl group;
It has a main chain skeleton consisting of titanoxane bonding units fTi-○ and siloxane bonding units Si-○, and the ratio of the total number of titanoxane bonding units to the total number of siloxane bonding units is within the range of 30:1 to 1:30. most of the silicon atoms of the siloxane bonding unit have one or two side chain groups selected from the group consisting of lower alkyl groups (preferably having 1 to 4 carbon atoms) and phenyl groups, Most of the titanium atoms in the titanoxane bonding unit have one or two lower alkoxy groups (preferably 1 to 4 carbon atoms) as side chain groups.
The ratio of the total number of fSi-CH2 structural units of the polycarbosilane to the total number of fTj-○ bond units and fSj-○ bond units of the polytitanosiloxane is 100:1 or less. The resulting mixture is heated in an organic solvent and under an atmosphere inert to the reaction to remove at least a portion of the silicon atoms of the polycarbosilane. A number consisting of a crosslinked polycarbosilane moiety and a polytitanosiloxane moiety, which is produced by bonding through an oxygen atom with at least a part of the silicon atoms and/or titanium atoms of the polytitanosiloxane. Average molecular weight is approximately 1
000 to 50,000 organometallic copolymer.

The organometallic copolymer used as an additive in the present invention can be obtained as a viscous liquid or powder.

Even when obtained as a powder, it can be easily made into a paper steel liquid by heating or melting, so unlike conventional powder additives, it is uniformly distributed throughout the base ceramic granules. can. Further, this organometallic copolymer is prepared in a vacuum, in an atmosphere of one or more selected from inert gas, reducing gas, and hydrocarbon gas.
By firing at a heating temperature of 00 to 2300℃,
Highly active Si, Ti, C, 0, and volatile substances are produced, and when these come into contact with the ceramic base, the competitiveness of the ceramic can be improved.

Furthermore, SIC, TIC, a solid solution of SIC and TIC produced from the highly active Si, Ti, and C, and TIC
, ~ (0 < suppresses abnormal grain growth of ceramic grains,
Furthermore, since the high melting point substance filling the grain boundaries has extremely high mechanical strength at high temperatures, excellent advantages such as not causing a decrease in the strength of the entire compact at high temperatures can be obtained. As mentioned above, ``organometallic copolymers used as additives are thermally decomposed by heating, and some carbon,
Organic substances containing hydrogen, oxygen, silicon, and titanium are dispersed as volatile components, and the remaining carbon, oxygen, silicon, and titanium react with the base ceramic to form a compound that fills the gaps between the ceramic powder particles. become.

The reaction starts at about 500°C and is completed at about 150,000°C. During this time, the ceramic particles are also self-sintered, and during this brazing, the additives not only act as a binder, but also act as a sintering aid and a grain growth inhibitor.
Since the various compounds formed at the ceramic grain boundaries during the heating process are composed of extremely small particles, usually 100A or less, the sintered body has excellent thermal shock resistance. In addition, these compounds are mainly SIC, T
Solid solution of IC, SIC and TIC and TIC, ~(0<
×<1) Sj3N4 (slightly produced when heated in N2) C, etc., so it has excellent high-temperature mechanical strength, oxidation resistance, corrosion resistance, and impact resistance, and has chemically stable properties. Therefore, these excellent properties are reflected in the entire Akatsuki Keitai. In the present invention, the above-mentioned additives are usually added and mixed in a range of 0.05 to 2% by weight to the ceramic powder.

The amount added varies depending on the pressure sintering method as described below, but if the amount added is less than 0.05% by weight, it is difficult to obtain a high-strength sintered body, and if it is added more than 20% by weight, the sintered body Since some swelling occurs and the strength deteriorates, it is advantageous that the amount added is usually within the range of 0.05 to 20% by weight. Further, in the present invention, a known heat-resistant ceramic is used as the ceramic, for example, the needle 203 "Shige○, M
Oxides such as g○, Zr02, Si02, SIC, TI
Carbide such as C, WC, B4C, Si3N4, BN, A
Examples include nitrides such as IN, shelving products such as TiB and Zr&, silicides such as MoSi2, WSj2, and CrSi2, and composite compounds thereof.

The shape of these heat-resistant ceramics is not particularly limited, but it is usually advantageous to use them by pulverizing them into powder. Furthermore, instead of the above-mentioned known heat-resistant ceramics, the organometallic copolymer itself used as an additive in the ceramics of the present invention is prepared in a vacuum using an inert gas, a reducing gas, or a hydrocarbon gas. A semi-mineralized fired product or a mineralized fired product obtained by firing in one or more atmospheres at a temperature range of 500 to 230,000 °C can be used.

Furthermore, in the present invention, the mixture of the organometallic copolymer and the ceramics is sintered in a vacuum, in an atmosphere containing at least one selected from an inert gas, a reducing gas, and a hydrocarbon gas. ~2300oo
This is done by heating.

Here, the inert gases include nitrogen gas, carbon dioxide gas, argon gas, etc., the reducing gases include hydrogen gas, carbon monoxide gas, etc., and the hydrocarbon gases include methane gas, ethane gas, propane gas, butane gas, etc., respectively.
Also, the baking temperature is preferably 800 to 2300 oo, and 80 to 2,300 oo.
If it is less than 0oo, mineralization of the mixed organometallic copolymer will not be completed, and if it is more than 2,300 qo, decomposition of SIC in the mineralized product of the mixed organometallic copolymer will occur, which is not preferable. Next, the method for performing dovetailing can be roughly divided into two methods: a method in which a mixture of ceramic particles and the organometallic copolymer is molded and then heated and hardened; or a hot press method in which the molding and hardening of the mixture are performed simultaneously. can be used.
In order to mold the mixture of ceramic powder and additives in the method in which molding and sintering are performed separately, a mold press method, a rubber press method, an extrusion method, and a sheet method are used.
It is possible to obtain a predetermined shape by applying pressure at a pressure of 0.00 to 5000 k9/ground.

Next, by competitively bonding the molded bodies, the heat-resistant ceramic competitively formed body of the present invention can be obtained. In addition, when sintering is performed using the hot press method, "graphite, alumina,
Select one that does not react with each ceramic base from among the hand-shaped ones made of nitrided shebalones, etc., and
A mixture of ceramic powder and additives can be pressed and heated at the same time to form a sintered body under a pressure of about 100 kg. In a preferred embodiment of the present invention, a mixture of an organometallic copolymer and a ceramic is heated in a vacuum with at least one gas selected from an inert gas, a reducing gas, and a hydrocarbon gas before being molded and fired. 8 in an atmosphere consisting of seeds
Preheat at below 00q0.

By carrying out such a treatment, the volumetric shrinkage of the ceramic sintered body is minimized, and a molded body with excellent dimensional accuracy can be obtained. Furthermore, as another preferred embodiment of the present invention, the method of the present invention can be used to apply a liquid organometallic copolymer to a ceramic molded body that has already been solidified by using a moat, spraying, etc.
Impregnation is carried out by operations such as coating, and if the organometallic copolymer is obtained in a solid state, it is made into a liquid by heating or dissolving in a solvent, and then impregnated by the above operation, and if necessary, by applying pressure. After increasing the degree of impregnation, a series of steps of heating in a temperature range of 80,020 to 23,000 C in vacuum or in an atmosphere of at least one selected from inert gas, reducing gas, and hydrocarbon gas. By performing the treatment at least once, a sintered compact with higher density and higher strength can be obtained.

The organometallic copolymer to be impregnated as described above must be in liquid form, so if these compounds can be obtained in liquid form at room temperature or at a relatively low heating temperature, they can be used as they are, or if necessary, the viscosity can be lowered. Therefore, a small amount of benzene, toluene, xylene, hexane, ether, tetrahydrofuraso, dioxane, chloroform, methylene chloride, petroleum ether, petroleum benzine, ligroin, chlorofluorocarbon, DMS○, DMm, and other solvents that can dissolve organometallic copolymers. In yet another embodiment of the method of the invention, the ceramic powder to be mixed with the organometallic copolymer in the step of making the initial blend of the invention As a ceramic powder obtained by firing an organometallic copolymer in a vacuum in an atmosphere consisting of at least one selected from inert gas, reducing gas, and hydrocarbon gas, and then pulverizing the organometallic copolymer, By using it, a high-density and high-strength Akatsuki formed body can be obtained.

In this case, the ceramic powder is mainly SIC, TIC
, solid solution of SIC and TIC and TIC, (0<×
<1) and also contains a small amount of C, Si3N4 (formed when heated in N2). In yet another embodiment of the method of the invention, the organometallic copolymer is The fired product obtained by firing at a temperature range of 500 to 2300 oo in an atmosphere consisting of at least one selected from medium, inert gas, and reducing gas, L hydrocarbon gas, and the above-mentioned organometallic copolymer A high-density and high-strength sintered material made of the same composite carbide as described above is produced by forming the composite without mixing and sintering it at a temperature range of 800 to 230,000 in the above atmosphere at the same time as this forming or after forming. Formation forms can be obtained.

The ceramic molded body obtained according to the present invention can be used not only for its heat resistance but also as a neutron absorbing material in the case of B4C, TiB2 and ZrB molded bodies.

In addition, {1} Building materials - panels, domes, trailer houses, walls, ceiling materials, flooring materials, cooling towers, septic tanks, sewage tanks, water supply tanks, hot water supply piping, drain pipes, heat pipes for heat conversion, etc. (2) Equipment materials for aircraft and space development - fuselages, wings, helicopter drive shafts, jet engine components.

Lesser, rotor, stator, blades, compressor casing, housing sog, nose cone, rocket nozzle, brake material, tire cord, etc. (3' Marine materials -
Boats, yachts, fishing boats, work boats, etc.'4) Road transport equipment materials - wheel fronts, side plates, water tanks, toilet units,
Seats, car bodies, containers, road equipment, guardrails, pallets, tanks for tank trucks, bicycles, motorcycles, etc. {51 Corrosion-resistant equipment materials - tussocks, tower ducts, staffs, pipes, etc. [6} Electrical materials, one-sided heating elements, Barristers, igniters, thermocouples, etc. (71 Sports equipment - boats, bows, skis, snowmobiles, water skis,
Glider aircraft, tennis rackets, golf shafts, helmets, bats, racing jackets, etc. {81 Mechanical elements - gaskets, packings, gears, brake materials, wear materials, abrasive materials, etc. [91 Medical equipment materials - prosthetic legs, artificial limbs, etc. Dish Acoustic equipment materials - Cantilever - Can be used for L tone arms, speaker cones, voice coils, etc.

The present invention will be explained below with reference to Examples.

Reference Example 1 5 Two and a half tons of anhydrous xylene and 400 tons of sodium were put into the three-necked flask, heated to the boiling point of xylene under a stream of nitrogen gas, and 1 portion of dimethyldichlorosilane was added dropwise over 1 hour.

After the dropwise addition was completed, the mixture was heated under reflux for one hour to form a precipitate.
This precipitate was treated in a furnace and washed first with methanol and then with water to obtain polydimethylsilane 420 as a white powder. On the other hand, 759 parts of diphenyldichlorosilane and 1 part of boric acid
24 days in n-butylene under nitrogen gas atmosphere, 1
The resulting white resinous material was further heated in vacuum at 40,000 °C for 1 hour to obtain polyborodiphenylsiloxane of 530 °C. Next, 250 g of the above polydimethylsilane and 8.27 g of the above polyborodiphenylsiloxane were added and mixed,
In two quartz tubes equipped with a reflux tube, under a nitrogen stream,
The mixture was heated to q0 and polymerized for 6 hours to obtain polycarbosilane to be used as a raw material for the copolymer of the present invention.

After cooling at room temperature, xylene was added to take out a solution, xylene was evaporated, and the mixture was concentrated under a nitrogen stream for 1 hour at 32.0 am to obtain a solid of 140 ml. The number average molecular weight of this polymer was 995 as measured by vapor pressure osmosis (VPO method). Reference Example 2 864 mm of diphenylsilanediol and 340 mm of titanium tetrabutoxide were weighed, xylene was added thereto, and 150,001 mm of titanium tetrabutoxide was weighed out under nitrogen gas.
A reflux reaction was carried out for a period of time.

After the completion of the reaction, the insoluble matter was filtered in an oven, and the solvent xylene was removed using an evaporator, and the obtained intermediate product was further polymerized by heating under 270 qC nitrogen gas for 3 minutes to obtain the raw material for the copolymer of the present invention. A polymer was obtained in which the ratio of the total number of titanoxane bonds to the total number of siloxane bonds was 1:4. The number average molecular weight is VP
It was 1200 by the O method. Example 1 Weigh out 40 kg of the poly-IJ carbosilane obtained in Reference Example 1 and 40 kg of the polytitanosiloxane obtained in Reference Example 2, and add Zyreso 400 to this mixture to form a homogeneous phase. A mixed solution was prepared, and a reflux reaction was carried out under a nitrogen gas atmosphere at 13,000 ℃ for 3 hours.

After the reflux reaction was completed, the temperature was further raised to 20,000, and the xylene solvent was distilled out.
■Perform polymerization. An organometallic copolymer was obtained. The number average molecular weight of this polymer was determined to be 2550 by the VPO method. Weight percent of this polymer 1 and S of 200 mesh or less
Mix 90% by weight of IC powder with an appropriate amount of benzene,
After drying, it was lightly crushed in a mortar and sized with a Tometshu 100 knot.

This mixed powder was pressure-molded at a molding pressure of 1500k9' to obtain a powder compact of 10 sides x 5 ribs x 5 sides. This compacted compact was heated at a heating rate of 200oC'hr in nitrogen gas for 12 hours.
It was heated and sintered to 00 qo. As a result, a SIC Akatsuki formed body having a high-density 2.51 ta' material and a bending strength of 12.1 kg' was obtained. Example 2 The reaction was carried out in the same manner as in Reference Example 2, except that 600 g of diphenylsilanediol and 394 g of titanium tetraisopropoxide were weighed, xylene was added thereto, the solvent was removed, and the reaction was carried out at 25 mm for 30 minutes. As a result, a polytitanosiloxane having a number average molecular weight of 960 and a ratio of the total number of titanoxane bonds to the total number of siloxane bonds of 1:2 was obtained to be used as a raw material for the copolymer of the present invention.

80 g of this polymer and 40 g of the polycarbosilane obtained in Reference Example 1 were weighed, 500 g of xylene was added to this mixture to make a mixed solution consisting of a homogeneous phase, and the mixture was incubated at 13,000 g for 2 hours under a nitrogen gas atmosphere. The reflux reaction was carried out while
After the reflux reaction was completed, the temperature was further raised to 200° C. to distill off the xylene solvent, and then polymerization was carried out at 20 pi for 2 hours to obtain an organometallic copolymer with a number average molecular weight of 5,000. Ki-Si-CH of the polycarbosilane part of this polymer
Total number of 2-na bonds versus fTi- of the polytitanosiloxane moiety
The ratio of the total number of ○chi bonds and BeSi-○chi bonds is approximately 7:4
It is. The weight percent of this polymer 1 and the weight percent of 200 mesh or less si3N4 powder 9 were mixed together with an appropriate amount of n-hexane, dried, and then heated at 100 qC'h in argon.
It was preheated and pulverized at 600° C. at a rising speed of r.

95% by weight of this powder and the above polytitanocarbosilane 5
% by weight was further mixed with an appropriate amount of n-hexane, dried, and pulverized. This mixed powder was pressure-molded at a molding pressure of 2000 kg' to obtain a green compact of 1 rib x 50 legs x 5 sides. This powder compact and 100oC' in argon
Competitive heating was achieved to 140,000 at a heating rate of hr. As a result, a Si3N4 formed body having a bulk density of 2.58 mm and a flexural strength of 10.5 k9' was obtained. 80% of titanosiloxane was weighed out, 400% benzene was added to this mixture to obtain a mixed solution consisting of a homogeneous phase, and a reflux reaction was carried out under a nitrogen atmosphere at 7000% for 5 hours.

After the reflux reaction was completed, the benzene was distilled off by further heating.2
Polymerization was carried out at 50q0 for 1 hour and the number average molecular weight was 7300.
An organometallic copolymer was obtained. The obtained polymer was a uniform transparent resinous material. The ratio of the total number of x-Si-CH2 na bonds in the polycarbosilane portion of this resin-like material to the total number of fTi-◯ bonds and tSi-◯ bonds in the polytitanosiloxane portion is about 31:1. 7% by weight of this polymer
and Q-M2039 box weight % of 200 mesh or less were mixed together with an appropriate amount of benzene, dried, and pulverized.

This mixed powder was pressure-molded at a molding pressure of 3,000 kg' to obtain a compacted powder having dimensions of 1 x 5 x 5 yanagi. This powder compact was heated to 1,000 °C at a heating rate of 200oC/hr in nitrogen.
It was heated to a temperature of 0.00. As a result, a high-density 3.0M' block,
A sintered molded body having a bending strength of 6.0k9/masu glue 203 was obtained.
Example 4 A powder compact was heated with nitrogen gas at a salting rate of 200 qC/hr.
Instead of heating to 20,000 °C, the compact was heated to 1,800 °C at a heating rate of 200 qC'hr in a mixed gas of carbon monoxide and nitrogen [CO:N2 = 1:4 (molar ratio)].
The SIC sintered body obtained by carrying out the same procedure as in Example 1, except for heating and sintering it to After drying the obtained impregnated molded body, it was soaked in a mixed gas of carbon monoxide and nitrogen [CO:N2=1:4 (molar ratio)] at 20%
It was heated and sintered to 1800°C at a salt rate of 00C/hr.

As a result of performing this series of impregnation, drying, and heating and coagulation twice, a SIC sintered body having a high density of 2.65 mm and a bending strength of 18.5 kg'' was obtained. Example 5 15% by weight of the organometallic copolymer obtained in Example 2 and 85% by weight of SIC powder of 200 mesh or less were mixed with an appropriate amount of n-hexane, dried, and heated at a heating rate of 10,000'hr in argon. It was preheated to 60,000 and ground.

This powder was set in a carbon die and hot pressed at 1800 oo for 0.5 hour under an argon stream.

As a result, the high density is 2.97 pm/earth and the bending strength is 24.5k.
A 9/m2 SIC sintered body was obtained. Example 6 The organometallic copolymer obtained in Example 1 was incubated in vacuum (10-
3 side Hg), was fired to 80,000 at an overflow rate of 100° C./hr, and the fired product was pulverized to 200 mesh or less.

Claims (1)

[Claims] 1 (1) A number average molecular weight of about 500 to 10,000,
It has a main chain skeleton mainly consisting of a structural unit of the formula -(Si-CH_2)-, and the silicon atom in the formula substantially contains a side chain group selected from the group consisting of a hydrogen atom, a lower alkyl group, and a phenyl group. a polycarbosilane having two, and (2)
Titanoxane bonding unit -(Ti-O)- and siloxane bonding unit -(
It has a main chain skeleton consisting of Si-O)-, and the ratio of the total number of titanoxane bond units to the total number of siloxane bond units is within the range of 30:1 to 1:30, and the silicon atoms of the siloxane bond units are Most of the titanium atoms in the titanoxane bonding unit have one or two side chain groups selected from the group consisting of lower alkyl groups and phenyl groups, and most of the titanium atoms in the titanoxane bonding unit have one lower alkoxy group as a side chain group. Or a polytitanosiloxane having two carbosilane, -(
Total number of Si-CH_2)- structural units versus -(Ti-O)- bonding units and -(Si-O) of the polytitanosiloxane
- mixing in a quantitative ratio such that the ratio of the total number of bonding units is within the range of 100:1 to 1:100, and heating the resulting mixture in an organic solvent and under an atmosphere inert to the reaction; , a crosslinked polyurethane produced by bonding at least a portion of the silicon atoms of the polycarbosilane with at least a portion of the silicon atoms and/or titanium atoms of the polytitanosiloxane via oxygen atoms. An organometallic copolymer having a number average molecular weight of about 1,000 to 50,000, consisting of a carbosilane part and a polytitanosiloxane part, is made of at least one selected from oxides, carbides, nitrides, borides, and silicides. and molding the resulting mixture, and at the same time or after the molding, an atmosphere consisting of at least one selected from inert gas, reducing gas, and hydrocarbon gas in a vacuum. Inside, 8
A method for producing a ceramic sintered body, characterized by heating and sintering within a temperature range of 00 to 2,300°C. 2. A mixture of the organometallic copolymer and the ceramics is heated at 800°C or lower in vacuum in an atmosphere consisting of at least one selected from inert gas, reducing gas, and hydrocarbon gas. After preheating, it is molded, and at the same time or after the molding, it is heated at 800 to 2300°C in a vacuum, in an atmosphere consisting of at least one selected from inert gas, reducing gas, and hydrocarbon gas. 2. A method according to claim 1, characterized in that heating and sintering is carried out within a temperature range. 3. As the ceramic, the organometallic copolymer is heated in vacuum in an atmosphere consisting of at least one selected from inert gas, reducing gas, and hydrocarbon gas.
The method according to claim 1 or 2, characterized in that ceramics obtained by firing within a temperature range of 00 to 2300°C are used. 4 Obtained by calcining the above-mentioned organometallic copolymer in a temperature range of 500 to 2300°C in vacuum in an atmosphere consisting of at least one selected from inert gas, reducing gas, and hydrocarbon gas. The fired product is molded, and at the same time or after the molding, in a vacuum, in an atmosphere consisting of at least one selected from inert gas, reducing gas, and hydrocarbon gas, at a temperature range of 800 to 2300 ° C. A method for producing a ceramic sintered body characterized by sintering.