JPH04193763A - Non oxide sintered body having improved workability and system using the same - Google Patents

Abstract

PURPOSE:To improve workability by sintering after mixing a prescribed molar ratio of a compound of metal element having specified ionic radius and a nonoxide ceramic. CONSTITUTION:Into the nonoxide ceramic incorporating >90vol.% of more than one kinds of silicon nitride, silicon carbide and zirconium boride consisting of elements each having <0.08nm ionic radius, for example, a fluoride, carbonate, nitrate, chloride, bromide, iodide or acetate of a metal element having >0.14nm ionic radius such as Ba, Rb or Cs and a compound decomposing below sintering temp. of sintered body to form metallic ions blended as 0.1-5mol% against the total sintered body. This blend is mixed, and after molding and sintering at a prescribed condition, a nonoxide sintered body having a structure in which the metallic ions exist at the boundary phase of the sintering body, a triple boundary point of the boundary phase and deposited material or the whole or a part of the boundary face. This sintered body is exemplified by the pressure cooker test in the condition, at 121 deg.C, 2 atm., 100% relative humidity lasting for 100hrs. and the weight difference per unit area of the sintered body by the test is <10<-3>g/cm<2>.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to ceramic members that require heat resistance and wear resistance, especially those that have a complex shape and are required to be processed with high precision in a short time. The present invention relates to a method for producing ceramics suitable for use as parts, and products made from such ceramics.

[Conventional technology]

Ceramic materials, which have better heat resistance and wear resistance than metals, are expected to be applied to gas turbine parts, automobile engine parts, etc.
l2O3, ZrO2, TiO□, carbide ceramic 5i
CSTic, ZrC, nitride ceramic 5i8z
AlzOzNs-z (0<=Z<-4,2),
5iJ4, TiN.

Various types of boride ceramics such as TiB2 and ZrB2 have been found. Each of these ceramics has its own characteristics, such as high strength, excellent abrasion resistance, and high hardness, and many inventions have been made to improve these characteristics. For example, with regard to nitride ceramic 5isN4, there are many inventions such as Japanese Patent Publication No. 58-1073 that improve the sinterability of 5isN4.Also, as an invention to improve the strength of these ceramics, ceramic fibers of the same type or different types are used as ceramic fibers. Method of blending into the matrix (Japanese Patent Publication No. 14637/1983)
Alternatively, there is a method of blending ceramic whiskers into the matrix (Japanese Patent Publication No. 54675/1983).

However, despite its excellent properties, ceramics have not yet been put into practical use as automotive engine parts, gas turbine parts, etc., due to their poor machinability, which contradicts their high strength and wear resistance. The main cause is high cost. In other words, if you try to process ceramic materials in the same way as ordinary metal materials, ceramic materials are brittle materials, so there will be many chips and dimensional accuracy cannot be achieved.
The machining unit (cutting allowance) per cycle must be reduced. For this reason, when processing metal or the like, the processing time is significantly increased and the heating cost is increased.

Of course, in order to overcome these drawbacks, attempts have been made to improve the workability of ceramics. These attempts are discussed, for example, in the February 1986 issue of Metals, pages 20 to 24.

[Problem to be solved by the invention]

The above-mentioned conventional techniques for improving workability have focused on improving the machinability of ceramics, so workability has certainly improved, but ceramics have poor heat resistance, abrasion resistance, high strength, etc. It has lost its characteristics and is suitable for use in heat insulating materials, etc., but cannot be applied to mechanical parts.

An object of the present invention is to provide a ceramic material suitable for mechanical parts such as engine parts and gas turbine parts, which has high workability while maintaining the heat resistance, abrasion resistance, and high strength of ceramics. be.

[Means to solve the problem]

In order to achieve the above object, the present inventors have conducted extensive research and found that a sintered body containing a metal element with an ionic radius of 0.14 nm or more in a proportion of O, 1 mol% or more and 5 mol% or less of the whole. Ionic radius of 0.08 nm, such as those present in grain boundary phases, grain boundary precipitates, triple points of grain boundaries, or grain boundaries.
Composed of the following elements, and 121'C12 atm,
A non-oxide material characterized by a weight change per unit area of a sintered body of 10-2 g/cm2 or less after 100 hours of PCT (pressure cooker test) conducted under conditions of 100% relative humidity. We discovered that sintered bodies have excellent properties, and we also performed mechanical processing such as grinding, cutting, and polishing on this material, molded it into a desired shape, and created ceramic parts, which were then used to manufacture engines, etc. The present invention was completed by configuring the system. In the present invention, the term "ion radius" is based on the value determined by Pauling's measurement.

If the metal element having an ionic radius of 0.14 nm or more is less than 0.1 mol % of the entire metal element, the effect of improving workability is not sufficient. In addition, if it exceeds 5mo1%, heat resistance, abrasion resistance, strength, etc. will deteriorate, so 0.1mol%
It is desirable that the content be 5 mol% or less.

Further, the ionic radius of the non-oxide sintered body serving as the matrix is 0.
It is desirable that the thickness be 0.08 nm or less. The reason for this will be explained in detail later, but it is due to the ionic radius ratio of 0.14 nm or more to a metal element that is added to improve workability. This is because a non-oxide sintered body having an ionic radius of 0.8 nm or more does not have a sufficient effect of improving workability.

Furthermore, since the non-oxide sintered bodies that serve as the base layer are used as structural materials for systems such as engines, they must have excellent environmental resistance. In other words, PCT (Pressure Cooker) is an accelerated environmental resistance test.
Even when the test) was conducted for 100 hours at 121°C, 12 atm, and 100% relative humidity, the components of the sintered body did not undergo decomposition, oxidation, or other changes, and the weight change per unit area was 10-3 g/ cff must be less than or equal to 12. A
Since IN, Ca3N3, etc. are unstable, when this test is performed, the weight changes greatly, making them unsuitable as structural ceramics.

As a metal element with an ionic radius of 0.14 nm or more, B
a, Rb, and Cs are suitable. Since other elements are radioactive, there are problems with their normal use. It has been confirmed that any non-oxide sintered body composed of an element with an ionic radius of 0.08 nm or less is effective, but nitride ceramics such as 516-zAl, 0□
N8z (0<=Z<=4.2), Si3N4, Ti
N, carbide ceramics such as 5iCSTiC and ZrC, and boride ceramics such as TiB2 and ZrB2 are particularly effective in improving workability.

Also, 0. The fact that the proportion of non-oxide sintered bodies having an ionic radius of 0.08 nm or more is 90% by volume or more means that Si
This is because materials such as 3N4 require the addition of a sintering aid. Unless the density of the sintered body is 90% or more of the theoretical density, it is difficult to process with high precision.

The ionic radius added to improve workability is 0, 14
As a method for causing metal elements of nm or larger to exist in the grain boundary phase, grain boundary precipitates, triple points of grain boundaries, or grain interfaces of a sintered body, these elements can be mixed with fluorides, carbonates, nitrates, chlorides, bromides,
An effective method is to mix and add an inorganic compound such as an iodide or an organic compound such as an acetic acid compound in the form of a compound that decomposes below the sintering temperature of the sintered body to form metal ions.

Compounds that do not decompose below the sintering temperature, such as BaS
Even if O4 and the like are added, they do not exist in grain boundary phases, grain boundary precipitates, triple points of grain boundaries, or grain interfaces, but instead exist in granular form, and do not exhibit any effect of improving workability.

The sintered body produced as described above has excellent heat resistance and abrasion resistance, and is suitable as a member that is required to have high strength, high precision, and low cost.

For example, it was possible to commercialize gas turbine blades and cylinders for automobile reciprocating engines using conventional technology, but the processing costs accounted for a very large proportion of the product, so the overall cost was high. It had not yet been commercialized. By using the ceramic material of the present invention, the proportion of processing costs in the product can be reduced without reducing the performance required for gas turbine blades and cylinders for automobile reciprocating engines, such as heat resistance and wear resistance. It is fully possible to

Mechanical seals for automobiles, home appliance pumps, petrochemicals,
Even when the present invention is applied to parts that require wear resistance, such as valves for the pharmaceutical industry and thread guides for textile machinery, it is possible to reduce product costs while taking advantage of the wear resistance and environmental resistance of ceramic materials. Therefore, it is possible to provide inexpensive and high-performance members. In addition, setters for semiconductor manufacturing jigs,
The same effect can be obtained when applied to crucibles, furnace core tubes, cutting tool thrower tips, etc. As shown in these examples, by applying the present invention, all parts that are put into practical use by being formed into a desired shape through mechanical processing such as grinding, cutting, and polishing can be processed to reduce the amount of processing that accounts for the total cost of the product. The cost ratio can be reduced. Therefore, it becomes possible to produce ceramic parts that were previously impossible to commercialize due to high costs. Therefore, the systems themselves, such as engines and machine tools, that use these parts,
We will be able to provide products with high performance and low prices.

[Function] Regarding the mechanism of the effect of improving workability when a metallic element with an ionic radius of 0.14 nm or more is present in the grain boundary phase, grain boundary precipitate, triple point of the grain boundary, or grain interface of the sintered body, It's not clear yet. What I am currently considering is the following.

■ To improve workability, we added many types of metal elements to the same non-oxide sintered body and observed changes in workability, and found that alkali metal and alkaline earth metal elements were effective. Ta. Even within the same group, elements with particularly large atomic weights have a remarkable processability-E effect, and an examination of their ionic radius revealed that elements with an ionic radius of 0.14 nm or more have a sufficient effect for practical use.

■ When the same alkaline earth metal element was added to many non-oxide sintered bodies and the change in workability was observed, it was found that the smaller the ionic radius of the constituent element, the more pronounced the effect of improving workability. Ta.

■ When observing with a transmission electron microscope the above items ■ and ■ that had a remarkable effect of improving workability, it was found that metallic elements were present in the grain boundary phase, grain boundary precipitates, triple points of grain boundaries, or grain boundaries. I found out that it was.

In addition, the above-mentioned phenomenon was not observed in the products in which almost no effect of improving workability was observed.

■ Observation of the fracture surface of the fractured specimens that had a remarkable effect of improving workability in ■ and The rate of internal destruction is high.

(2) Even for the metal elements that had a remarkable effect of improving workability in (1) and (2) above, the effect of improving workability differs depending on the method of addition. These elements are decomposed into metal ions using inorganic compounds such as fluorides, carbonates, nitrates, chlorides, bromides, and iodides, or organic compounds such as acetic acid compounds, and at a temperature below the sintering temperature of the sintered body. When mixed and added in the form of such compounds, there is an effect of improving processability, but when mixed and added in the form of stable compounds such as sulfates and oxides, the effect is small. When we etched the materials that were less effective with sulfuric acid etc., we found that the added metal elements were scattered in granular form.

From the above, the mechanism for improving workability can be inferred as follows.

i.e. fluorides, carbonates, nitrates, chlorides, bromides,
A metal element having an ionic radius of 0.14 nm or more mixed and added in the form of an inorganic compound such as an iodide or an organic compound such as an acetate compound is decomposed during sintering to liberate the metal element.

These metal elements are impurities for the non-oxide sintered body of the matrix. Impurities are more energetically stable if they exist in grain boundary phases, grain boundary precipitates, triple points of grain boundaries, or grain interfaces. Therefore, impurities generally tend to exist in grain boundary phases, grain boundary precipitates, triple points of grain boundaries, or grain boundaries.

However, this ease of existence is thought to be related to the ratio of the ionic radius of the non-oxide sintered body of the matrix to the ionic radius of the added metal element.

In other words, when the size of the latter is smaller than that of the former, the constituent elements of the non-oxide sintered body of the matrix are more likely to exist in grain boundary phases, grain boundary precipitates, triple points of grain boundaries, or grain boundaries. Since a substitutional solid solution is more likely to be energetically stable, if the latter is larger than the former, grain boundary phases, grain boundary precipitates, triple points of grain boundaries, or grain boundaries exist. It is thought that then.

According to our experiments, the ionic radius size ratio is 1.5.
It has been found that when the amount is more than twice as large, grain boundary phases, grain boundary precipitates, grain boundary triple points, or grain interfaces are particularly likely to be formed. Forming grain boundary phases improves workability because the grain boundary phases formed in this way are weaker than the strength within the crystal grains of the parent phase. When such a sintered body is ground or cut, this grain boundary phase is selectively destroyed. In other words, grain boundary destruction increases.

Generally, in the case of intragranular fracture, the crack that occurs once in the material during cutting progresses linearly through the crystal grains, so the crack propagation distance becomes longer, and as a result, the cracked part of the material becomes larger. .

In many cases, machining with high dimensional accuracy is not possible because there are many large pieces of material, that is, large chips, on the surface of the machined surface. Furthermore, since grinding and cutting are performed while destroying the inside of the grain, which has high strength, the energy required for processing, that is, the processing resistance, increases, resulting in increased wear of the grindstone used for processing.

On the other hand, in the case of grain boundary fracture, when grinding or cutting is performed, the crack passes through the grain boundaries and progresses while bending. Since a crack loses crack propagation energy each time it changes its direction of propagation, the distance the crack propagates is shorter than if the crack propagates linearly due to intragranular fracture. In other words, since chipping is reduced, processing with high dimensional accuracy becomes possible. In addition, since the grain boundaries, which have a lower strength than the inside of the grains, are selectively destroyed, the energy required for grinding is reduced, and the grindstone used for grinding and cutting requires less wear, resulting in lower processing costs.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to Examples.

Examples: Ba element fluoride BaF 2 powder, carbonate BaC0+ powder, carbide ceramic SiC (added 2 wt% AIN), nitride ceramic Si 5.5A1o, 500
．． Each powder of 6N7.5.5i3N4 (added with 5Wt96 MgO) was added with 0. Imo1%, 2mo1%
, 5 mol %, 10 mol % added and those without addition were weighed, mixed for 24 hours using a ball mill, granulated and compacted, and this compact was I
1 hour in a vacuum of X 10'Torr, 300kg/
Hot press sintering was carried out under the pressure of CRJ. The density of these sintered bodies was measured by the water displacement method. In addition, in order to quantitatively compare the workability, the sintered body thus obtained was processed into a test piece with a width of 4 mm, a height of 3 mm, and a length of 35 mm.
Using a diamond blade with a diameter of 300 mm and a blade thickness of 0.2 mm, cutting was performed 10 times at right angles to the longitudinal direction, and the grinding resistance and the maximum chip size were measured.

The measurement results are summarized in Table 1. Note that the density is expressed as a relative value to the theoretical density.

It can be seen that the grinding resistance and maximum cutting dimension of the Ba compound, BaF2, BaC (L + non-added ones (test Na1, 10.19) are larger than those with Ba compound added.BaP 2, BaCO3 respectively 0.1
When mol% or more is added, both the grinding resistance and the maximum cut size become smaller, but when 10mol% or more is added, the thickness becomes thick again.Also, the density is also 10m
o1% added (Test N (L5.9.14.23.
It can be seen that 27) has become extremely bad. From this, in order to improve workability and obtain a healthy sintered body with sufficiently high sintered density, the amount of Ba compound added is 0°1 mo.
It can be seen that 1% to 5mo1% is desirable.

(Margins below this page) Table 1 Example 2 Nitride ceramics Si3N4 (5wt as sintering aid)
% of MgO) to BaO1Ba(NOa)2, Ba
Compared to Br2, BaC12, Ba12, and Ba(OH)2, the Sr compound 5rP2, which is an element in the same group as Ba and has one cycle smaller (therefore, the ionic radius is also smaller), is 0 and 0, respectively.
1. 2. Weighed the one with 5.10 mo1% added and the one without additive for comparison, mixed for 24 hours using a ball mill, granulated and compacted, and this compact was
Sintered at 00°C for 1 hour under nitrogen. The density of these sintered bodies was measured by the water displacement method. In addition, in order to quantitatively compare the workability, the sintered body thus obtained was cut into 4mm width and 3m height.
After processing into a test piece with a length of 35 mm, the particle size was #300.
The specimen was cut 10 times at right angles to the longitudinal direction using a diamond blade with a blade thickness of 0.2 mm, and the grinding resistance and the maximum chip size were measured. The measurement results are summarized in Table 2. The density is shown as a relative value to the theoretical density. In this table, the one without additives (test Nα28) and Ba
Added compounds other than elements (test Nα53-5G
) is one to which a compound of Ba element is added (test Nα29~
It can be seen that both the grinding resistance and the maximum grinding size are larger than those of 52). Even if Ba compound is added, the amount of addition is 10
When mo1% is reached (Test N (L32.36.40°44
, 48.52) There is a tendency for the density to decrease and for both the grinding resistance and the maximum cut size to increase again. From this, Ba
It is considered desirable that the amount of the element added is 0.1 mol% to 5m01%.

(Margin below this page) Table 2 Example 3 Nitride ceramics 5isN4 (5wt as sintering aid)
% MgO) SiC, TiC, ZrC, B4C to improve the fracture toughness value of the powder and make it a tough material.
Furthermore, BaCO was added to each powder by aowt%.
2 powder to 0.1. 2. 5. Weighed the one with 1% lOmo added and the one without BaC0s added for comparison,
Mixing was carried out for 24 hours using a ball mill, followed by granulation and compacting, and the compact was hot pressed at 1800°C for 1 hour under a pressure of aookg/al in 2A fine nitrogen to form a sintered compact. Created. The sintered body thus obtained was used in Example 1.
In the same manner as above, the density, grinding resistance, and maximum cutting dimension were measured. The results are summarized in Table 3.

(Margins below this page) Table 3: The fracture toughness of the materials added with SiC, TiC, ZrC, and B4C is improved, so the grinding resistance is almost unchanged compared to the materials without the addition of SiC, TiC, ZrC, and B4C (Test Nα19 in Example 1). However, the maximum hanging size is smaller.

In addition to these systems, 0.1 mol% or more of BaC (L+
By adding , the grinding resistance becomes smaller and the maximum cutting size becomes smaller. Even in these systems, Bact
When the amount of 3 added is 10mo1%, the density decreases rapidly,
Grinding resistance and maximum cutting size also tend to increase.

Example 4 2 mo1% B was added to ceramic powder as shown in Table 4.
Those with and without aC0a added were weighed, mixed for 24 hours using a ball mill, granulated and compacted, and the compacts were hot pressed under a pressure of 300 kg/- in 1 atm of nitrogen. A sintered body was produced.

The sintered body thus obtained was subjected to measurements of density, grinding resistance, and maximum cut size in the same manner as in Example 1. In addition, to examine the environmental resistance, we also examined the weight change per unit area of the sintered body after 100 hours of PCT (pressure cooker test) conducted at 121°C, 2 atmospheres, and 100% relative humidity. . From these results, it can be seen that the samples to which BaC03 is added have a slightly lower sintered density than those without BaC03, but both the grinding resistance and the crack size are smaller, and the workability is improved.

However, it can be seen that AIN is not suitable as a structural ceramic because the weight change per unit area of the sintered body after 100 hours of PCT is around 10-''g/cm2. -'g/cm2 or less, and it is considered that there is almost no change in weight.

(Margin below this page) Table 4 Example 5 2 mo1 in Si6, 5AlO, 500, 5N75 powder
% of BaCO5 powder and as a comparison,
Weigh the CO5 powder without additives and use a ball mill to measure 2.
The mixture was mixed for 4 hours, granulated, and compacted, and the compact was fired in nitrogen in IATM to obtain a sintered body. These sintered bodies were processed into rotor blades for gas turbines as shown in Fig. 1. Si6, 5A10.5 with BaCO5 added
00.5N? , s has good workability, so the processing was completed in about A time compared to the additive-free material. In addition, the wear of the grindstone used for processing was less than that of products processed without BaCO5 additives.

Example 6 Nitride ceramics S! 5 as a sintering aid to 3N4 powder
A sample to which wt% of MgO was added and 2 mo1% of barium acetate powder to the Si3N4 powder was weighed, and a sample to which no barium acetate powder was added for comparison were weighed, mixed in pure water for 24 hours using a wet ball mill, and then granulated. , perform green compact molding,
This molded body was fired in nitrogen at 1 atm to obtain a sintered body. These sintered bodies were processed into valves for the petrochemical industry as shown in FIG.

At this time, the time required for processing was approximately 172 hours with the addition of 2 mo1% barium acetate powder compared to the time required without addition. We also compared the amount of wear on the pulp after opening and closing the valve 100,000 times, and found that there was almost no difference in the amount of wear between the pulp with and without 2mol1% barium acetate powder added. .

〔Effect of the invention〕

Since the present invention is configured as described above, it is possible to manufacture ceramic parts with good dimensional accuracy in a short time, and it is possible to manufacture ceramic parts with good dimensional accuracy in a short time. Ceramics can now be applied to parts with complex shapes. As a result, highly functional ceramic parts can be manufactured at low cost. Therefore, by adopting these ceramic parts,
It will be possible to supply systems such as engines and machine tools that are inexpensive, have high performance, and are highly durable.

[Brief explanation of the drawing]

FIG. 1 shows a rotor blade for a gas turbine manufactured from a Si5.5Alo, sho, 5Nv5 sintered body to which BaCO5 is added in Example 5 of the present invention. FIG. 2 shows a pulp for the petrochemical industry produced from the Si2N4 sintered body to which notrium acetate powder was added in Example 6 of the present invention.

Claims (25)

[Claims] 1. Metal elements with an ionic radius of 0.14 nm or more are present in the grain boundary phase, grain boundary precipitates, triple points of grain boundaries, or grain boundaries of the sintered body at a ratio of 0.1 mol% to 5 mol% of the whole. Or a part of it is composed of existing elements with an ionic radius of 0.08 nm or less, and 12
PCT performed under conditions of 1°C, 2 atm, and 100% relative humidity.
The weight change per unit area of the sintered body after 100 hours of (pressure cooker test) was 10^-^3
A non-oxide sintered body characterized in that it is less than g/cm^2. 2. In the non-oxide sintered body according to claim 1, the metal element having an ionic radius of 0.14 nm or more is Ba, Rb, or Cs.
A sintered body characterized by: 3. The non-oxide sintered body according to claim 1, wherein the non-oxide sintered body composed of an element having an ionic radius of 0.08 nm or less contains SiC in an amount of 90% or more by volume. sintered body. 4. The non-oxide sintered body according to claim 1, wherein the non-oxide sintered body composed of an element with an ion diameter of 0.08 nm or less contains Si_3N_4 in an amount of 90% by volume or more. sintered body. 5. In the non-oxide sintered body according to claim 1, the non-oxide sintered body composed of an element having an ionic radius of 0.08 nm or less has the general formula Si_6_-_zAl_zO_zN_8_
The composition represented by z (0<=Z<=4.2) is
A sintered body characterized by containing at least % by volume. 6. The non-oxide sintered body according to claim 1, wherein the non-oxide sintered body composed of an element with an ionic radius of 0.08 nm or less contains Tic in an amount of 90% or more by volume. sintered body. 7. The non-oxide sintered body according to claim 1, wherein the non-oxide sintered body composed of an element with an ionic radius of 0.08 nm or less contains B_4C at 90% by volume or more of the total. sintered body. 8. The non-oxide sintered body according to claim 1, wherein the non-oxide sintered body composed of an element with an ionic radius of 0.08 nm or less contains TaC at 90% by volume or more of the total. sintered body. 9. The non-oxide sintered body according to claim 1, wherein the non-oxide sintered body composed of an element with an ionic radius of 0.08 nm or less contains TiB_2 at 90% by volume or more of the whole. sintered body. 10. The non-oxide sintered body according to claim 1, wherein the non-oxide sintered body composed of an element with an ionic radius of 0.08 nm or less contains WC at 90% by volume or more of the total. sintered body. 11. In the non-oxide sintered body according to claim 1, the non-oxide sintered body composed of an element having an ionic radius of 0.08 nm or less is one or two of ZrC, VC, HfC, and NbC.
A sintered body characterized in that it contains at least 90% by volume of at least one species. 12. In the non-oxide sintered body according to claim 1, the non-oxide sintered body composed of an element having an ionic radius of 0.08 nm or less is one or more of VN, NbN, TaN, HfN, and ZrN. A sintered body characterized by containing 90% or more by volume of the whole. 13. In the non-oxide sintered body according to claim 1, the non-oxide sintered body composed of an element having an ionic radius of 0.08 nm or less contains one or more of CaB_6, TaB_2, and ZrB_2 in a total of 90% of the total. A sintered body characterized by containing at least % by volume. 14. A sintered body comprising two or more of the sintered bodies according to claims 1 to 12. 15. The sintered body according to claim 1, wherein the density of the sintered body is 90% or more of the theoretical density. 16. A metal element with an ionic radius of 0.14 nm or more is in a proportion of 0.1 mol% or more and 5 mol% or less of the whole,
As a method of making these elements exist in the grain boundary phase, grain boundary precipitates, triple points of grain boundaries, or grain interfaces of the sintered body, these elements can be added to fluoride,
Inorganic compounds such as carbonates, nitrates, chlorides, bromides, and iodides, or organic compounds such as acetic acid compounds, mixed in the form of compounds that decompose below the sintering temperature of the sintered body and become metal ions. A method for producing a sintered body, characterized by adding the following: 17. Grinding, cutting the sintered body according to claims 1 to 12,
A gas turbine blade characterized by being formed into a desired shape by machining such as polishing. 18. Grinding, cutting the sintered body according to claims 1 to 12,
A cylinder for an automobile reciprocating engine characterized by being formed into a desired shape by machining such as polishing. 19. Grinding, cutting the sintered body according to claims 1 to 12,
A mechanical seal characterized by being formed into a desired shape through mechanical processing such as polishing. 20. Grinding, cutting the sintered body according to claims 1 to 12,
A valve for the petrochemical and pharmaceutical industries that is formed into a desired shape through mechanical processing such as polishing. 21. Grinding, cutting the sintered body according to claims 1 to 12,
A thread guide for textile machinery characterized by being formed into a desired shape by mechanical processing such as polishing. 22. Grinding, cutting the sintered body according to claims 1 to 12,
Semiconductor manufacturing jigs, such as setters, crucibles, and furnace core tubes, characterized by being formed into desired shapes by mechanical processing such as polishing. 23. Grinding, cutting the sintered body according to claims 1 to 12,
A throw-away tip for a cutting tool that is formed into a desired shape by machining such as polishing. 24. Grinding, cutting the sintered body according to claims 1 to 12,
A ceramic member characterized by being formed into a desired shape by machining such as polishing. 25. A system such as an engine, a machine tool, etc. constructed using the ceramic member according to claim 17 to 23.