JPH0547498B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention is characterized in that R is a combination of one or more elements selected from elements that can be divalent to trivalent cations.
A solid solution phase with the composition R _y Zr ₄ Si _x P _6-x O ₂₄ (x is a number of 0 to 2, y is a number of 2/3 to 2 that satisfies the electrical neutrality condition of the chemical formula), Regarding the heat-resistant sintered body made of the solid solution phase and its manufacturing method, more specifically, R _y Zr ₄ Si _x having excellent heat resistance and high temperature stability
The present invention relates to a solid solution phase having a P _6-x O ₂₄ composition, a heat-resistant, high-strength sintered body comprising the solid solution phase that has excellent low expansion properties and high-temperature thermal stability, and a method for producing the same. [Prior Art] In recent years, with the progress of industrial technology, there has been an increasing demand for materials with excellent heat resistance and low expansion properties. In response to these demands, zirconyl phosphate [(ZrO) ₂ P ₂ O ₇ ] has been found to be promising as a material with excellent heat resistance and low expansion. Furthermore, recently, zirconium phosphate of an alkali metal such as sodium has been proposed as a material having heat resistance and a low coefficient of thermal expansion. (Mat.Res.
Bull., Vol.19, pp.1451−1456 (1984), Journal
of Materials Science 16, 1633−1642 (1981),
and Ceramic Industry Association Journal 95 [5], pp. 531-537 (1987)) Furthermore, phosphate compounds of alkaline earth metals with specific compositions have also been proposed as having low expansion properties. (Mat.Res.Bull., Vol.20,
pp.99−106, 1985, and J.Am.Ceram.Soc., 70
[10] C-232 to C-236 (1987)) Also, in U.S. Patent No. 4,675,302, Ca _0.5
Ceramic materials having a basic composition of Ti ₂ P ₃ O ₁₂ have been proposed as having excellent low expansion properties. [Problems to be Solved by the Invention] However, although phosphate compounds such as the above-mentioned zirconyl phosphate have the advantage of having excellent low expansion properties, they undergo thermal decomposition at high temperatures of 1200°C or higher, resulting in phosphorus It is mentioned that the (P) component evaporates. For example, when heat treated at 1400°C for 100 hours, there is a problem in that zirconyl phosphate shows a weight loss of 19% and sodium zirconium phosphate shows a weight loss of 36%. Furthermore, the ceramic material proposed in U.S. Patent No. 4,675,302 is mainly used for the substrate of a low-expansion optical reflector that does not undergo deformation even with temperature changes for artificial satellites. Second
As shown in the figure, the temperature change is intended to be at most about 500°C, and no consideration is given to stability, heat resistance, etc. at high temperatures of, for example, 1200°C or higher. On the other hand, CaZr ₄ P ₆ O ₂₄ , SrZr ₄ P ₆ O ₂₄ , BaZr ₄ P ₆ O ₂₄
Compared to zirconyl phosphate, phosphate compounds such as phosphate have superior stability at high temperatures, and the weight loss after heat treatment at 1400℃ for 100 hours is less than 10%.
CaZr ₄ P ₆ O ₂₄ has a negative thermal expansion coefficient and low strength, and SrZr ₄ P ₆ O ₂₄ has high strength but a relatively high thermal expansion coefficient of 25 × 10 ^-7 /℃. can be,
Heat-resistant ceramics with high strength and low expansion properties have been desired. By the way, the method for producing phosphate compounds is as follows:
Na ₂ CO ₃ , ZrO ₂ , ZrOCl ₂・8H ₂ O, SiO ₂ ,
(NH ₄ ) ₂ HPO ₄ , H ₃ PO ₄ , Nb ₂ O ₅ , Y ₂ O ₃ , SrCO ₃ ,
A method using a combination of K ₂ CO ₃ , CaCO ₃ and the like is known. [T.Oota and I.Yamai, Journal
of the American Ceramic Society, 69 , 1.
(1986)] However, in the above production method, during the decomposition process of ammonium phosphate or H ₃ PO ₄ ,
The P ₂ O ₅ component is generated independently, forming areas with a locally high phosphorus concentration, and producing low melting point compounds during sintering. For this reason, giant pores (voids) are created in the sintered body, mainly in the low melting point compound,
A serious defect will occur. [Means for Solving the Problem] Therefore, in order to solve the problems of the above-mentioned prior art, the present inventor conducted various studies and found that R is Ca,
When it is composed of elements that _can form divalent to trivalent cations such as Sr, Ba, _and Y, the heat resistance _of the crystal phase and _high temperature thermal _stability are _excellent .
Various R _y Zr ₄ P ₆ O _{24 ( 2 /} 3≦y≦1,
(R is a combination of one or more elements that can be divalent or trivalent cations) Each compound forms a complete solid solution, and solid solution changes the properties of R _y Zr ₄ P ₆ O ₂₄ itself, such as thermal expansion behavior and It was discovered that thermal properties etc. can be controlled, and a sintered body with high strength and low expansion can be obtained while maintaining heat resistance and high temperature thermal stability. In addition, as shown in equation (1), it is possible to form a solid solution in which part of the P ions are replaced by Si ions and R ions at the same time, and by solid solution R _y Zr ₄ Si _x
It was discovered that the properties of P _6-x O ₂₄ itself, such as thermal expansion behavior and thermal properties, can be controlled, and a heat-resistant, low-expansion material with superior high-temperature thermal stability while maintaining heat resistance and strength can be obtained. This led to the completion of the present invention. R _y Zr ₄ P ₆ O ₂₄ +xSi ⁴⁺ +1/nR′ ⁿ⁺ −xP ⁵⁺ R _y R′ _1/o ZrSi _x P _6-x O ₂₄ ……(1) (n is the valence of R) That is, According to the present invention, _{R is} composed of one _or more _combinations of elements selected from elements that can be divalent to trivalent _cations . satisfies the electrical neutrality condition of the chemical formula 2/
a solid solution phase having a composition of 3 or more and 2 or less, a heat-resistant sintered body consisting of the solid solution phase, and ZrP ₂ O ₇ ,
(ZrO) ₂ P ₂ O ₇ , ZrO ₂ , Zr(OH) ₄ , ZrSiO ₄ , SiO ₂ ,
Ry by molding and firing a batch mixture selected from R phosphate, R silicate, and RO (R is an element that can be a divalent or trivalent cation) _.
R _y consisting of precipitating Zr ₄ Si _x P _6-x O ₂₄
A method for producing a heat-resistant sintered body comprising a solid solution phase having a Zr ₄ Si _x P _6-x O ₂₄ composition is provided. The solid solution phase of the present invention having a composition of R _y Zr ₄ Si _x P _6-x O ₂₄ can be applied not only as a sintered body alone but also as a composite with a heat-resistant compound such as zircon or zirconia. It can also be applied as a constituent compound. The solid solution phase of the present invention having a composition of R _y Zr ₄ Si _x P _6-x O ₂₄ is R
is a combination of one or more elements selected from elements that can become divalent or trivalent cations, and x is 0
It is necessary that the value be a value greater than or equal to 2 and y be a value greater than or equal to 2/3 and less than or equal to 2. If R contains a monovalent cation, the high temperature thermal stability will be poor, and if x exceeds 2, the heat resistance will decrease. By satisfying these conditions, a solid solution phase with excellent heat resistance and high temperature stability can be obtained. R is a combination of one or more elements that can become divalent or trivalent cations, and generally corresponds to a of the periodic table.
It is preferably composed of at least one of barium (Ba), strontium (Sr), and calcium (Ca). Furthermore, according to the sintered body of the present invention, the open porosity is
Within the range of 50% or less, the weight loss rate due to phosphorus evaporation after heat treatment at 1400℃ for 100 hours is reduced to 10%.
The bending strength can be as low as 100 Kg/cm ² or more. In other words, when the open porosity exceeds 50%, the bending strength decreases.
It becomes less than 100Kg/cm ² and does not satisfy the required strength when using ceramics as a practical material.
Furthermore, this sintered body has a softening rate under its own weight of 0.3% or less after heat treatment at 1400°C for 5 hours, which satisfies the requirements as a heat-resistant material. In addition, this sintered body has a small dimensional change rate,
When heat treated at 1400°C for 100 hours, the dimensional change rate was less than 1%, which also satisfies the requirements for a heat-resistant material. Furthermore, this sintered body has a low thermal expansion coefficient of 25×10 ^-7 /°C or less from room temperature to 1400°C, and has excellent thermal shock resistance. Therefore, the sintered body of the present invention having the above characteristics can be used in ceramic honeycomb structures such as automotive exhaust gas purification catalyst carriers, rotary regenerator type ceramic heat exchangers, heat transfer type heat exchangers, and turbocharger rotors. It is suitably applied to materials that require heat resistance and thermal stability at high temperatures, such as automobile housings, engine manifold insulation materials, diesel particulate filters, etc. Next, in the method for producing a heat-resistant sintered body according to the present invention, the raw materials are ZrP ₂ O ₇ , (ZrO) ₂ P ₂ O ₇ ,
ZrO ₂ , Zr(OH) ₄ , ZrSiO ₄ , SiO ₂ , R phosphate,
It is characterized in that it is a batch mixture of powders consisting of a substance selected from R silicate and RO (R is an element that can be a divalent or trivalent cation). That is,
ZrP ₂ O ₇ , (ZrO) ₂ P ₂ O ₇ , ZrO ₂ , Zr(OH) ₄ ,
ZrSiO ₄ , SiO ₂ , R phosphate, R silicate,
and RO are very stable compounds, hardly causing non-uniformity during the molding and firing process, and can be fired at high temperatures, making it possible to obtain ceramics with excellent heat resistance. On the other hand, when phosphoric acid, which is conventionally used, is used as a P ₂ O ₅ source, since phosphoric acid is a liquid, it becomes non-uniform during the mixing process, forming locally high-concentration areas as described above. and produces compounds with low melting points. For this reason, a serious defect occurs in which huge pores are formed in the sintered body mainly in the low melting point compound. In addition, when obtaining a honeycomb structure by extrusion molding clay containing phosphoric acid, the corrosive nature of phosphoric acid may cause the extrusion die or cylinder of the extrusion molding machine to rust or corrode, resulting in significant molding failure. It becomes difficult. Furthermore, when applied to press molding, it has the disadvantage that molding as a powder is essentially impossible due to the phosphoric acid content. Also ZrP ₂ O ₇ , (ZrO) ₂ P ₂ O ₇ , ZrO ₂ , Zr(OH) ₄ ,
ZrSiO ₄ , SiO ₂ , R phosphate, R silicate and RO usually contain 0 to 82.9% by weight of ZrP ₂ O ₇ ,
(ZrO) ₂ P ₂ O ₇ is 0-79.5% by weight, ZrO ₂ is 0-50.4%
Weight %, Zr(OH) ₄ is 0 to 56.8 weight %, ZrSiO ₄ is 0
~38.0 wt%, _SiO2 0-12.5 wt%, R phosphate 0-44.9 wt%, R silicate 0-35.5
% by weight, RO is blended at a ratio of 0 to 37.3% by weight, among which ZrP ₂ O ₇ , (ZrO) ₂ P ₂ O ₇ and one or more of R phosphates, RO, R The silicate of R or the phosphate of R must necessarily be included in the batch mixture. In addition, RO, which is a raw material component, is
It is also possible to select and use RO, ie, stable compounds such as hydroxides, carbonates, and sulfates that are converted into oxides. In addition, the average particle size of the raw material is usually 50 μm or less,
Preferably, one with a diameter of 10 μm or less is used. As the firing conditions for the sintered body of the present invention, the firing temperature is
The temperature is 1400°C or higher, preferably 1400 to 1800°C, and the firing time is 1 to 24 hours, preferably 2 to 10 hours. By setting the firing temperature to 1400℃ or higher, R _y Zr ₄ Si _x
P _6-x O ₂₄ is fully analyzed and the sintered body of the present invention can be obtained. Furthermore, if the firing time is less than 1 hour, sintering is insufficient, and if it exceeds 24 hours, strength decreases due to abnormal grain growth and precipitation of different phases occurs due to evaporation of phosphorus. The preferred embodiments of the present invention explained above are summarized as follows. (a) R _y Zr ₄ consisting of a combination of one or more elements selected from elements in which R can be a divalent or trivalent cation
P ₆ O ₂₄ (y has a value of 2/3 or more and 1 or less that satisfies the electrical neutrality condition of the chemical formula) composition solid solution phase,
and a heat-resistant sintered body comprising the solid solution phase. (b) R is composed of one or more of Ba, Sr, and Ca R _y Zr ₄ Si _x P _6-x O ₂₄ (x is a number from 0 to 2, y is a number from 1 to 2) a heat-resistant sintered body comprising a solid solution phase, and a heat-resistant sintered body comprising the solid solution phase. (c) A heat-resistant sintered body consisting of a solid solution phase with a composition of R _y Zr ₄ Si _x P _6-x O ₂₄ whose weight loss rate is 10% or less when heat treated at 1400°C for 100 hours. (d) Open porosity is 50% or less, bending strength is 100Kg/cm ²
The above heat-resistant sintered body comprises a solid solution phase with a composition of R _y Zr ₄ Si _x P _6-x O ₂₄ . (e) Self-weight softening rate after heat treatment at 1400℃ for 5 hours is 0.3
% or less, a heat-resistant sintered body consisting of a solid solution phase with a composition of R _y Zr ₄ Si _x P _6-x O ₂₄ . (f) Dimensional change rate after heat treatment at 1400℃ for 100 hours is 1%
A heat-resistant sintered body having a solid solution phase having the following composition R _y Zr ₄ Si _x P _6-x O ₂₄ . (g) Thermal expansion coefficient from room temperature to 1400℃ is 25×
10 ^-7 /℃ or less, a sintered body consisting of a solid solution phase with a composition of R _y Zr ₄ Si _x P _6-x O ₂₄ . (h) R _y used as ceramic honeycomb structure
A sintered body consisting of a solid solution phase with a composition of Zr ₄ Si _x P _6-x O ₂₄ . (i) A heat-resistant composite containing a R _y Zr ₄ Si _x P _6-x O ₂₄ composition solid solution phase as a main crystalline phase and a heat-resistant compound such as zircon or zirconia as a second crystalline phase. (j) A method for producing a sintered body in which R is a solid solution phase having a composition R _y Zr ₄ Si _x P _6-x O ₂₄ composed of one or more of Ba, Sr, and Ca. (k) A method for producing a sintered body comprising a solid solution phase with a composition of R _y Zr ₄ Si _x P _6-x O ₂₄ selected from hydroxides, carbonates, and sulfates in which RO is converted to RO during firing. (l) A method for producing a sintered body comprising a solid solution phase having a composition of R _y Zr ₄ Si _x P _6-x O ₂₄ , wherein the firing temperature is 1400°C or higher and the firing time is 1 to 24 hours. [Examples] The present invention will be explained below based on Examples.
It will be clear that the invention is not limited to these examples. (Examples, Comparative Examples) Zirconyl phosphate [(ZrO) ₂ P ₂ O ₇ ] whose particle size was adjusted in advance according to the formulation ratio listed in Table 1,
ZrP ₂ O ₇ , calcium carbonate, strontium carbonate,
Barium carbonate, ittria, zircon, sodium carbonate, ammonium hydrogen phosphate, silica, calcium phosphate, and zirconia were mixed. In Comparative Example 25, a mixture of the formulations shown in Table 1 was filled into an alumina crucible, held in an electric furnace in the atmosphere at 1000°C for 12 hours, and then pulverized to obtain a batch mixture. To adjust the particle size of zirconyl phosphate, a particle with a diameter of approximately 5 mm is used.
A vibrating mill filled with ZrO ₂ sintered cobblestones was used, but the particle size can also be adjusted using a pot mill or attritor. ZrO ₂ sintered cobblestones stabilized with MgO and Y ₂ O ₃ were used. The chemical composition of the boulders used is shown in Table 2. Further, chemical analysis values of the raw materials used are shown in Table 3. 10% in 100 parts by weight of the mixture of the formulations shown in Table 1
Add 5 parts by weight of PVA aqueous solution and mix thoroughly.
After press molding in a 25 x 80 x 6 mm mold at a pressure of 100 kg/cm ² , a rubber press was performed at a pressure of 2 tons/cm ² and dried. After drying, this molded body was fired in an electric furnace in the atmosphere under the conditions shown in Table 1. The heating rate was 5 to 1700°C/hr. After firing, this fired body is 3 x 4 x 40 mm as shown in JIS R1601 (1981).
The weight loss and dimensional change rate during heat treatment at 1400℃ for 100 hours, coefficient of thermal expansion from 40 to 1400℃, 4-point bending strength, softening under self-weight, and open porosity were measured. . A push rod differential thermal dilatometer using a high-purity alumina sintered body was used to measure the thermal expansion coefficient. The measurement temperature range is 40-1400℃. Four-point bending strength was measured according to the method shown in JIS R1601. The self-weight softening rate is calculated by placing the 3 x 4 x 40 mm bending test piece between supports with a width of 30 mm as shown in Figure 8, and heat-treating it at 1400°C for 5 hours in the air. By measuring the amount of deformation Δx, it was determined by the following formula. Self-weight softening rate=△x/l×100 (%) The open porosity was measured by the Archimedes method. The melting point is calculated using a sintered body cut into a shape of 3 x 4 x 5 mm.
It was heat-treated for 10 minutes in an electric furnace at 1700°C, and visually judged whether or not it melted. The solid solution phase with the composition R _y Zr ₄ Si _x P _6-x O ₂₄ is JCPDS33
−321 CaZr ₄ (PO ₄ ) ₆ , JCPDS33−1360 and SrZr ₄
(PO ₄ ) ₆ or BaZr ₄ (PO ₄ ) ₆ of JCPDS34-95, and when indexing was possible, it was determined that a solid solution phase was generated. Other crystal phases were identified based on the X-ray diffraction pattern based on their presence or absence. The lattice constant of the solid solution phase is R _y
(018) surface reflection peak angle 2θ of Zr ₄ Si _x P _6-x O ₂₄ ,
(208) Plane spacing d ₀₁₈ from the plane reflection peak angle, and
d ₂₀₈ was determined, and a and c were calculated according to the following simultaneous equations. 1/d ² ₀₁₈ = 4/3a ² +64/c ² 1/d ² ₀₁₈ = 16/3a ² +64/c ²

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[Table] As is clear from the results of Examples 1 to 19 and Comparative Examples 21 to 26 shown in Table 1, R is a combination of one or more elements selected from elements that can become divalent to trivalent cations, and x is By setting it to 0 or more and 2 or less, a R _y Zr ₄ Si _x P _6-x O ₂₄ composition solid solution phase according to the present invention and a heat-resistant sintered body made of the solid solution phase can be obtained. In addition, these solid solution phases and sintered bodies are ZrP ₂ O ₇ ,
(ZrO) ₂ P ₂ O ₇ , ZrO ₂ , Zr(OH) ₄ , ZrSiO ₄ , SiO ₂ ,
R phosphate, R silicate, and RO (R is 2
- Elements that can become trivalent cations) were sintered under the firing conditions shown in Table 1. Figure 1 shows the relationship between chemical composition and crystal lattice constant in the CaZr ₄ P ₆ O ₂₄ -SrZr ₄ P ₆ O ₂₄ solid solution system and the CaZr ₄ P ₆ O ₂₄ -BaZr ₄ P ₆ O ₂₄ solid solution system, and Figure 2 shows the relationship between the chemical composition and crystal lattice constant.
Figure ₃ shows the relationship between the chemical composition in the CaZr ₄ P ₆ O ₂₄ -SrZr ₄ P ₆ O ₂₄ solid solution system, _{the thermal} expansion coefficient and _the four-point bending strength of the sintered body. The relationship between the chemical composition in _{the 6} O ₂₄ solid solution system, the thermal expansion coefficient and the four-point bending strength of the sintered body is shown in Figure 4. R _y Zr ₄ Si _x
Chemical composition and sintered body in P _6-x solid solution system at 1400℃
Figure 5 shows the relationship between the weight loss rate when held for 100 hours, and the relationship between the chemical composition of the R _y Zr ₄ Si _x P _6-x O ₂₄ solid solution phase and the coefficient of thermal expansion of the sintered body. From the above, when R consists of a combination of one or more selected from elements that can be divalent to trivalent cations, the heat resistance of the crystal phase and high temperature thermal stability are excellent, and furthermore, R _y Zr ₄ P ₆ O ₂₄ (2/3≦y≦
1) Composition It is found that the properties of the solid solution phase itself can be controlled, and a high-strength, low-expansion sintered body with excellent heat resistance and high-temperature thermal stability can be obtained. In addition, the solid solution phase in which part of the P ions are replaced with Sr ions and R ions at the same time has better high-temperature thermal stability, and the properties of the solid solution phase itself with the composition R _y Zr ₄ Si _x P _6-x O ₂₄ are improved. It can be seen that a heat-resistant sintered body with excellent high-temperature thermal stability, high strength, and low expansion can be obtained. Note that FIG. 6 is a graph showing the relationship between the open porosity and the bending strength of a sintered body consisting of a solid solution phase with a composition of R _y Zr ₄ Si _x P _6-x O ₂₄ . In addition, FIG. 7 shows the powder X-ray diffraction pattern of the sintered body of Example 16 at room temperature, and shows Sr _1.5
This shows that it consists of a single solid solution phase with a composition of Zr ₄ SiP ₅ O ₂₄ . [Effect of the invention] As explained above, R of the present invention is R _y Zr ₄ Si _x P _6-x O ₂₄ (x is 0 2 or less, y has a value of 2/3 or more and 2 or less that satisfies the electrical neutrality condition of the chemical formula) Composition solid solution phase,
According to the heat-resistant sintered body consisting of the solid solution phase and its manufacturing method, it has a solid solution phase of R _y Zr ₄ Si _x P _6-x O ₂₄ composition, high strength, low expansion, and high temperature stability. A sintered body with excellent heat resistance can be obtained. Therefore, this R _y Zr ₄ Si _x P _6-x O ₂₄ composition solid solution phase and the sintered body made of the solid solution phase are required to have heat resistance, low expansion property, and high temperature stability, such as extrusion molding. When formed into a honeycomb structure by, for example, a rotating heat storage type ceramic heat exchanger, a heat transfer type heat exchanger, a diesel particulate filter, and
It can be widely applied to insulation materials in ceramic turbo charger rotor housings or engine manifolds molded by slurry casting, press molding, injection molding, etc.

[Brief explanation of the drawing]

Figure 1 shows CaZr ₄ P ₆ O ₂₄ -SrZr ₄ P ₆ O ₂₄ composition solid solution phase,
and CaZr ₄ P ₆ O ₂₄ −BaZr ₄ P ₆ O ₂₄ composition A graph showing the relationship between the chemical composition of the solid solution phase and the lattice constant, Figure 2 is
CaZr ₄ P ₆ O ₂₄ −SrZr ₄ P ₆ O ₂₄ Composition Graph showing the relationship between the chemical composition of a sintered body consisting of a solid solution phase, the coefficient of thermal expansion from room temperature to 1400°C, and the four-point bending strength, Part 3
The figure is a graph showing the relationship between the chemical composition of a sintered body consisting of a solid solution phase of CaZr ₄ P ₆ O ₂₄ -BaZr ₄ P ₆ O ₂₄ , the coefficient of thermal expansion from room temperature to 1400°C, and the four-point bending strength. The figure shows Examples 1 to 10, 14 to 18, and Comparative Examples 21 to 25.
A bar graph showing the weight loss rate during heat treatment at 1400℃ for 100 hours. Figure 5 shows the chemical composition of the sintered body consisting of a solid solution phase of R _y Zr ₄ Si _x P _6-x O ₂₄ and the weight loss rate from room temperature to 1400℃. Figure 6 is a graph showing the relationship between the thermal expansion coefficients of R _y Zr ₄
A graph showing the relationship between open porosity and four-point bending strength of a sintered body consisting of a solid solution phase with a composition of Si _x P _6-x O _24. Figure 7 is a graph showing the powder X-ray diffraction pattern of Example 16 at room temperature. , FIG. 8 is a diagram showing a method of measuring the self-weight softening rate.

Claims (1)

[Claims] R _y Zr ₄ Si _x where 1 R is a combination of one or more elements selected from elements that can be divalent to trivalent cations.
A solid solution phase with a composition of P _6-x O ₂₄ (x has a value of 0 or more and 2 or less, and y has a value of 2/3 or more and 2 or less that satisfies the electrical neutrality condition of the chemical formula). 2. A heat-resistant sintered body comprising the solid solution phase according to claim 1. 3 ZrP ₂ O ₇ , (ZrO) ₂ P ₂ O ₇ , ZrO ₂ , Zr(OH) ₄ ,
ZrSiO ₄ , SiO ₂ , R phosphate, R silicate,
and RO (R is an element that can be a divalent to trivalent cation) and calcined to precipitate the solid solution phase according to claim 1, and the main component of the crystal phase is according to claim 1. A method for producing a heat-resistant sintered body, characterized by obtaining a sintered body consisting of a solid solution phase.