High temperature resistant special ceramic and its preparation method

Abstract

This invention belongs to the field of special ceramics preparation technology, specifically relating to a high-temperature resistant special ceramic and its preparation method. The high-temperature resistant special ceramic, by weight, comprises the following raw materials: 22-24 parts calcined kaolin, 20-22 parts andalusite, 30-32 parts tabular corundum, 2.5-4.5 parts calcite, 1.3-2.3 parts cerium phosphate, 15-17 parts calcium zirconate, 3.7-4.7 parts yttrium oxide, 2-3 parts titanium diboride, and 1.2-2.2 parts gadolinium trioxide. The high-temperature resistant special ceramic of this invention uses tabular corundum, calcined kaolin, and andalusite as main raw materials, calcite and cerium phosphate as sintering aids, and calcium zirconate, yttrium oxide, titanium diboride, and gadolinium trioxide as fillers, ensuring that the prepared special ceramic exhibits excellent flexural strength and fracture toughness at high temperatures.

Description

Technical Field

[0001] This invention belongs to the field of special ceramics preparation technology, specifically relating to a high-temperature resistant special ceramic and its preparation method. Background Technology

[0002] Specialty ceramics (also known as high-performance ceramics, advanced ceramics, fine ceramics, etc.) are a component of new materials. They possess various superior properties not found in other materials, such as high temperature resistance, high strength, light weight, wear resistance, corrosion resistance, and excellent electrical, magnetic, acoustic, optical, and thermal properties.

[0003] Currently, the high-temperature and mechanical properties of special ceramics are improved by adding sintering aids or fillers. However, due to poor raw material selection and process control, the addition of these aids or fillers often leads to defects such as poor mixing between ceramic raw materials, abnormal grain growth, and numerous sintering pores. This results in limited improvement in the strength and thermal stability of special ceramic materials, such as excessive brittleness, low strength, and insufficient heat resistance. Therefore, developing a method to improve the high-temperature resistance and mechanical properties of special ceramics, thereby extending their service life, is of paramount importance. Summary of the Invention

[0004] The purpose of this invention is to provide a high-temperature resistant special ceramic, which has excellent high-temperature resistance and mechanical properties. This invention also provides a method for its preparation.

[0005] The high-temperature resistant special ceramic of the present invention has the following raw material composition by weight: 22-24 parts calcined kaolin, 20-22 parts andalusite, 30-32 parts tabular corundum, 2.5-4.5 parts calcite, 1.3-2.3 parts cerium phosphate, 15-17 parts calcium zirconate, 3.7-4.7 parts yttrium oxide, 2-3 parts titanium diboride, and 1.2-2.2 parts gadolinium trioxide.

[0006] in:

[0007] The chemical composition of calcined kaolin, by mass percentage, is as follows: Al2O3 33.6%, SiO2 55.1%, Fe2O3 2.2%, MgO 2.8%, K2O 3.7%, and loss on ignition 2.6%.

[0008] Andalusite, by mass percentage, has the following chemical composition: Al2O3 61.29%, SiO2 37.45%, Fe2O3 0.42%, MgO 0.21%, TiO2 0.05%, and loss on ignition 0.58%.

[0009] The chemical composition of tabular corundum, by mass percentage, is as follows: Al2O3 99.290%, Na2O 0.478%, K2O 0.005%, SiO2 0.070%, Fe2O3 0.030%, CaO 0.026%, MgO 0.092%, TiO2 0.009%.

[0010] The method for preparing high-temperature resistant special ceramics according to the present invention comprises the following steps:

[0011] (1) Weigh out calcined kaolin, andalusite, tabular corundum, calcite, cerium phosphate, calcium zirconate, yttrium oxide, titanium diboride and gadolinium trioxide in a certain weight ratio and mix them evenly;

[0012] (2) The high-temperature resistant special ceramic raw materials, zirconium balls and water weighed in step (1) are added to a ball mill jar for wet ball milling. The resulting slurry is then sieved once, vacuum dried, sieved twice and granulated to prepare powder. The powder is then isostatically pressed to prepare green body.

[0013] (3) The green body prepared in step (2) is first heated to 600℃ at a heating rate of 5℃ / min and held for 30-33min. Then it is sintered in an argon atmosphere sintering furnace. After sintering, it is first cooled to 1000℃ at a cooling rate of 2℃ / min and then naturally cooled to room temperature with the furnace to obtain high temperature resistant special ceramics.

[0014] In step (2), the mass ratio of the high-temperature resistant special ceramic raw material, zirconium balls, and water is 1:1.7:0.8.

[0015] In step (2), the wet ball milling speed is 250-300 r / min and the ball milling time is 24 h.

[0016] In step (2), the obtained slurry is sieved once through a 200-mesh sieve, vacuum dried at 85°C, and then sieved a second time through an 80-mesh sieve before granulation.

[0017] In step (2), the isostatic pressing pressure is 250 MPa and the isostatic pressing time is 3 min.

[0018] The sintering process described in step (3) involves first heating the temperature to 900℃ at a rate of 2℃ / min and holding it for 80-90 min, then heating the temperature to 1350℃ at a rate of 4℃ / min and holding it for 60-65 min, and finally heating the temperature to 1700-1720℃ at a rate of 5℃ / min and holding it for 2.5 h.

[0019] In step (3), pre-firing is first performed to remove adsorbed water and other impurities, and then sintering is carried out in an Ar atmosphere. Segmented temperature control sintering is adopted. First, the temperature is raised to 900℃ to ensure that calcite decomposes in this temperature range and carbon dioxide gas can be completely removed to avoid the generation of bubbles and cracks. Then, the temperature is raised to 1350℃ to ensure the formation of mullite. Finally, the temperature is raised to 1700-1720℃ to ensure the final densification of high temperature resistant special ceramics.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) The high-temperature resistant special ceramic of the present invention uses tabular corundum, calcined kaolin, and andalusite as the main raw materials. The calcined kaolin and andalusite form a mullite phase during subsequent sintering. The mullite phase generated by the transformation of calcined kaolin and andalusite improves the high-temperature creep resistance of the material. At the same time, the transformation characteristics of andalusite help to reduce the mullite formation energy barrier and promote the formation of interlocking structures of needle-like mullite. After sintering, a multiphase ceramic matrix mainly composed of corundum and mullite is formed. The corundum phase provides extremely high high-temperature strength and hardness, while the mullite phase has excellent thermal stability and low coefficient of thermal expansion, so that the prepared high-temperature resistant special ceramic has excellent high-temperature resistance and flexural strength. Calcite and cerium phosphate are added as sintering aids. The calcium oxide produced by the decomposition of calcite and cerium phosphate begin to form a liquid phase at a lower temperature. Through the liquid phase sintering mechanism, the transport of materials and particle rearrangement are promoted, the sintering temperature is significantly reduced, and densification is promoted. The presence of cerium phosphate can also improve the high-temperature oxidation resistance of the ceramic. Adding calcium zirconate, yttrium oxide, titanium diboride, and gadolinium trioxide as fillers improves the high-temperature performance and mechanical properties of the prepared ceramics.

[0022] (2) The high-temperature resistant special ceramics of the present invention have a synergistic effect among the fillers calcium zirconate, yttrium oxide, titanium diboride, and gadolinium trioxide. Among them, calcium zirconate, as an inert filler, is uniformly dispersed in the matrix, which can optimize the overall thermal expansion coefficient of the ceramic, inhibit the abnormal growth of matrix grains, and improve the thermal stability of the ceramic. Yttrium oxide reacts with Al2O3 in the matrix at high temperature to form yttrium aluminum garnet in situ. The yttrium aluminum garnet phase has an ultra-high melting point and excellent high-temperature strength. The formed yttrium aluminum garnet phase exists in the intergranular form, which can "pin" the grain boundaries, purify and strengthen the grain boundaries, eliminate the adverse effects of the low-melting-point glass phase, and improve the creep resistance and high-temperature bending strength of the ceramic at high temperatures. The introduction of titanium diboride can improve the hardness of the ceramic. Its high thermal conductivity helps the heat to spread rapidly, avoids cracking due to local thermal stress, and improves the fracture toughness of the ceramic. Gadolinium trioxide can dissolve in the grain boundary glass phase, improve its viscosity and high-temperature stability, thereby achieving grain boundary strengthening. Thus, the synergistic effect of these four factors results in high-temperature resistant special ceramics with excellent high-temperature stability, flexural strength, and fracture toughness.

[0023] (3) The method for preparing high-temperature resistant special ceramics described in this invention ensures uniform mixing of raw materials through high ball-to-material ratio, long-term wet ball milling and secondary sieving and granulation. High isostatic pressing pressure reduces sintering difficulty and shrinkage deformation risk. The segmented sintering process ensures the densification of the structure of the high-temperature resistant special ceramics.

[0024] (4) The high-temperature resistant special ceramics prepared by the preparation method described in this invention have excellent bending strength and fracture toughness at high temperatures. Detailed Implementation

[0025] Example 1

[0026] The high-temperature resistant special ceramic described in Example 1 has the following raw material composition by weight: 23 parts calcined kaolin, 21 parts andalusite, 31 parts tabular corundum, 3.5 parts calcite, 1.8 parts cerium phosphate, 16 parts calcium zirconate, 4.2 parts yttrium oxide, 2.5 parts titanium diboride, and 1.7 parts gadolinium trioxide.

[0027] The chemical composition of calcined kaolin, by mass percentage, is as follows: Al2O3 33.6%, SiO2 55.1%, Fe2O3 2.2%, MgO 2.8%, K2O 3.7%, and loss on ignition 2.6%.

[0028] Andalusite, by mass percentage, has the following chemical composition: Al2O3 61.29%, SiO2 37.45%, Fe2O3 0.42%, MgO 0.21%, TiO2 0.05%, and loss on ignition 0.58%.

[0029] The chemical composition of tabular corundum, by mass percentage, is as follows: Al2O3 99.290%, Na2O 0.478%, K2O 0.005%, SiO2 0.070%, Fe2O3 0.030%, CaO 0.026%, MgO 0.092%, TiO2 0.009%.

[0030] The preparation method of the high-temperature resistant special ceramics described in Example 1 consists of the following steps:

[0031] (1) Weigh out calcined kaolin, andalusite, tabular corundum, calcite, cerium phosphate, calcium zirconate, yttrium oxide, titanium diboride and gadolinium trioxide in a certain weight ratio and mix them evenly;

[0032] (2) The high-temperature resistant special ceramic raw materials, zirconium balls and water weighed in step (1) are added to a ball mill jar for wet ball milling. The resulting slurry is then sieved once, vacuum dried, sieved twice and granulated to prepare powder. The powder is then isostatically pressed to prepare green body.

[0033] (3) The green body prepared in step (2) is first heated to 600℃ at a heating rate of 5℃ / min and held for 31min. Then it is sintered in an argon atmosphere sintering furnace. After sintering, it is first cooled to 1000℃ at a cooling rate of 2℃ / min and then naturally cooled to room temperature with the furnace to obtain high temperature resistant special ceramics.

[0034] In step (2), the mass ratio of the high-temperature resistant special ceramic raw material, zirconium balls, and water is 1:1.7:0.8.

[0035] In step (2), the wet ball milling speed is 270 r / min and the ball milling time is 24 h.

[0036] In step (2), the obtained slurry is sieved once through a 200-mesh sieve, vacuum dried at 85°C, and then sieved a second time through an 80-mesh sieve before granulation.

[0037] In step (2), the isostatic pressing pressure is 250 MPa and the isostatic pressing time is 3 min.

[0038] The sintering process described in step (3) involves first heating the temperature to 900℃ at a rate of 2℃ / min and holding it for 85 min, then heating the temperature to 1350℃ at a rate of 4℃ / min and holding it for 63 min, and finally heating the temperature to 1710℃ at a rate of 5℃ / min and holding it for 2.5 h.

[0039] Example 2

[0040] The high-temperature resistant special ceramic described in Example 2 has the following raw material composition by weight: 24 parts calcined kaolin, 20 parts andalusite, 32 parts tabular corundum, 4.5 parts calcite, 1.3 parts cerium phosphate, 15 parts calcium zirconate, 3.7 parts yttrium oxide, 3 parts titanium diboride, and 2.2 parts gadolinium trioxide.

[0041] in:

[0042] The chemical composition of calcined kaolin, by mass percentage, is as follows: Al2O3 33.6%, SiO2 55.1%, Fe2O3 2.2%, MgO 2.8%, K2O 3.7%, and loss on ignition 2.6%.

[0043] Andalusite, by mass percentage, has the following chemical composition: Al2O3 61.29%, SiO2 37.45%, Fe2O3 0.42%, MgO 0.21%, TiO2 0.05%, and loss on ignition 0.58%.

[0044] The chemical composition of tabular corundum, by mass percentage, is as follows: Al2O3 99.290%, Na2O 0.478%, K2O 0.005%, SiO2 0.070%, Fe2O3 0.030%, CaO 0.026%, MgO 0.092%, TiO2 0.009%.

[0045] The preparation method of the high-temperature resistant special ceramics described in Example 2 consists of the following steps:

[0046] (1) Weigh out calcined kaolin, andalusite, tabular corundum, calcite, cerium phosphate, calcium zirconate, yttrium oxide, titanium diboride and gadolinium trioxide in a certain weight ratio and mix them evenly;

[0047] (2) The high-temperature resistant special ceramic raw materials, zirconium balls and water weighed in step (1) are added to a ball mill jar for wet ball milling. The resulting slurry is then sieved once, vacuum dried, sieved twice and granulated to prepare powder. The powder is then isostatically pressed to prepare green body.

[0048] (3) The green body prepared in step (2) is first heated to 600℃ at a heating rate of 5℃ / min and held for 33min. Then it is sintered in an argon atmosphere sintering furnace. After sintering, it is first cooled to 1000℃ at a cooling rate of 2℃ / min and then naturally cooled to room temperature with the furnace to obtain high temperature resistant special ceramics.

[0049] In step (2), the mass ratio of the high-temperature resistant special ceramic raw material, zirconium balls, and water is 1:1.7:0.8.

[0050] In step (2), the wet ball milling speed is 300 r / min and the ball milling time is 24 h.

[0051] In step (2), the obtained slurry is sieved once through a 200-mesh sieve, vacuum dried at 85°C, and then sieved a second time through an 80-mesh sieve before granulation.

[0052] In step (2), the isostatic pressing pressure is 250 MPa and the isostatic pressing time is 3 min.

[0053] The sintering process described in step (3) involves first heating the temperature to 900℃ at a rate of 2℃ / min and holding it for 80min, then heating the temperature to 1350℃ at a rate of 4℃ / min and holding it for 65min, and finally heating the temperature to 1720℃ at a rate of 5℃ / min and holding it for 2.5h.

[0054] Example 3

[0055] The high-temperature resistant special ceramic described in Example 3 has the following raw material composition by weight: 22 parts calcined kaolin, 22 parts andalusite, 30 parts tabular corundum, 2.5 parts calcite, 2.3 parts cerium phosphate, 17 parts calcium zirconate, 4.7 parts yttrium oxide, 2 parts titanium diboride, and 1.2 parts gadolinium trioxide.

[0056] The chemical composition of calcined kaolin, by mass percentage, is as follows: Al2O3 33.6%, SiO2 55.1%, Fe2O3 2.2%, MgO 2.8%, K2O 3.7%, and loss on ignition 2.6%.

[0057] Andalusite, by mass percentage, has the following chemical composition: Al2O3 61.29%, SiO2 37.45%, Fe2O3 0.42%, MgO 0.21%, TiO2 0.05%, and loss on ignition 0.58%.

[0058] The chemical composition of tabular corundum, by mass percentage, is as follows: Al2O3 99.290%, Na2O 0.478%, K2O 0.005%, SiO2 0.070%, Fe2O3 0.030%, CaO 0.026%, MgO 0.092%, TiO2 0.009%.

[0059] The preparation method of the high-temperature resistant special ceramics described in Example 3 consists of the following steps:

[0060] (1) Weigh out calcined kaolin, andalusite, tabular corundum, calcite, cerium phosphate, calcium zirconate, yttrium oxide, titanium diboride and gadolinium trioxide in a certain weight ratio and mix them evenly;

[0061] (2) The high-temperature resistant special ceramic raw materials, zirconium balls and water weighed in step (1) are added to a ball mill jar for wet ball milling. The resulting slurry is then sieved once, vacuum dried, sieved twice and granulated to prepare powder. The powder is then isostatically pressed to prepare green body.

[0062] (3) The green body prepared in step (2) is first heated to 600℃ at a heating rate of 5℃ / min and held for 30min. Then it is sintered in an argon atmosphere sintering furnace. After sintering, it is first cooled to 1000℃ at a cooling rate of 2℃ / min and then naturally cooled to room temperature with the furnace to obtain high temperature resistant special ceramics.

[0063] In step (2), the mass ratio of the high-temperature resistant special ceramic raw material, zirconium balls, and water is 1:1.7:0.8.

[0064] In step (2), the wet ball milling speed is 250 r / min and the ball milling time is 24 h.

[0065] In step (2), the obtained slurry is sieved once through a 200-mesh sieve, vacuum dried at 85°C, and then sieved a second time through an 80-mesh sieve before granulation.

[0066] In step (2), the isostatic pressing pressure is 250 MPa and the isostatic pressing time is 3 min.

[0067] The sintering process described in step (3) involves first heating the temperature to 900℃ at a rate of 2℃ / min and holding it for 90min, then heating the temperature to 1350℃ at a rate of 4℃ / min and holding it for 60min, and finally heating the temperature to 1700℃ at a rate of 5℃ / min and holding it for 2.5h.

[0068] Comparative Example 1

[0069] The preparation method of the high-temperature resistant special ceramic described in Comparative Example 1 is the same as that in Example 1, the only difference being the raw material composition. The high-temperature resistant special ceramic described in Comparative Example 1, by weight, has the following raw material composition: 23 parts calcined kaolin, 21 parts andalusite, 31 parts tabular corundum, 3.5 parts calcite, 1.8 parts cerium phosphate, 4.2 parts yttrium oxide, 2.5 parts titanium diboride, and 1.7 parts gadolinium trioxide.

[0070] Comparative Example 2

[0071] The preparation method of the high-temperature resistant special ceramic described in Comparative Example 2 is the same as that in Example 1, the only difference being the raw material composition. The high-temperature resistant special ceramic described in Comparative Example 2, by weight, has the following raw material composition: 23 parts calcined kaolin, 21 parts andalusite, 31 parts tabular corundum, 3.5 parts calcite, 1.8 parts cerium phosphate, 16 parts calcium zirconate, 2.5 parts titanium diboride, and 1.7 parts gadolinium trioxide.

[0072] Comparative Example 3

[0073] The preparation method of the high-temperature resistant special ceramic described in Comparative Example 3 is the same as that in Example 1, the only difference being the raw material composition. The high-temperature resistant special ceramic described in Comparative Example 3, by weight, has the following raw material composition: 23 parts calcined kaolin, 21 parts andalusite, 31 parts tabular corundum, 3.5 parts calcite, 1.8 parts cerium phosphate, 16 parts calcium zirconate, 4.2 parts yttrium oxide, and 1.7 parts gadolinium trioxide.

[0074] Comparative Example 4

[0075] The preparation method of the high-temperature resistant special ceramic described in Comparative Example 4 is the same as that in Example 1, the only difference being the raw material composition. The high-temperature resistant special ceramic described in Comparative Example 4, by weight, has the following raw material composition: 23 parts calcined kaolin, 21 parts andalusite, 31 parts tabular corundum, 3.5 parts calcite, 1.8 parts cerium phosphate, 16 parts calcium zirconate, 4.2 parts yttrium oxide, and 2.5 parts titanium diboride.

[0076] The high-temperature resistant special ceramics prepared in Examples 1-3 and Comparative Examples 1-4 were subjected to performance tests. The room temperature flexural strength of the high-temperature resistant special ceramics was tested according to GB / T 6569-2006. For the high-temperature performance test, the special ceramics were heated to 1500℃ at a heating rate of 10℃ / min, held at that temperature for 4 hours, and then cooled in the furnace. The flexural strength was then tested according to GB / T 6569-2006, and the flexural strength retention rate was calculated. The fracture toughness of the high-temperature resistant special ceramics was tested according to GB / T 23806-2009. The results are shown in Table 1 below.

[0077] Table 1. Test results of high-temperature resistant special ceramics

[0078]

[0079] As shown in Table 1 above, the high-temperature resistant special ceramics prepared in Examples 1-3 exhibit excellent flexural strength, high-temperature resistance, and fracture toughness. Comparing Example 1 with Comparative Examples 1-4 reveals a synergistic effect among calcium zirconate, yttrium oxide, titanium diboride, and gadolinium trioxide in the raw materials for the high-temperature resistant special ceramics, resulting in excellent high-temperature resistance and mechanical properties.

[0080] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A high temperature resistant specialty ceramic, characterized by: The raw material composition by weight is as follows: calcined kaolin 22-24 parts, andalusite 20-22 parts, tabular corundum 30-32 parts, calcite 2.5-4.5 parts, cerium phosphate 1.3-2.3 parts, calcium zirconate 15-17 parts, yttrium oxide 3.7-4.7 parts, titanium diboride 2-3 parts, gadolinium trioxide 1.2-2.2 parts; The calcined kaolin, by mass percentage, has the following chemical composition: Al2O3 33.6%, SiO2 55.1%, Fe2O3 2.2%, MgO 2.8%, K2O 3.7%, and loss on ignition 2.6%. Andalusite, by mass percentage, has the following chemical composition: Al₂O₃ 61.29%, SiO₂ 37.45%, Fe₂O₃ 0.42%, MgO 0.21%, TiO₂ 0.05%, and loss on ignition 0.58%. The chemical composition of tabular corundum, by mass percentage, is as follows: Al₂O₃ 99.290%, Na₂O 0.478%, K₂O 0.005%, SiO₂ 0.070%, Fe₂O₃ 0.030%, CaO 0.026%, MgO 0.092%, TiO₂ 0.009%; The preparation method of the high-temperature resistant special ceramics comprises the following steps: (1) Weigh out calcined kaolin, andalusite, tabular corundum, calcite, cerium phosphate, calcium zirconate, yttrium oxide, titanium diboride and gadolinium trioxide in a certain weight ratio and mix them evenly; (2) The high-temperature resistant special ceramic raw materials, zirconium balls and water weighed in step (1) are added to a ball mill jar for wet ball milling. The resulting slurry is then sieved once, vacuum dried, sieved twice and granulated to prepare powder. The powder is then isostatically pressed to prepare green body. (3) The green body prepared in step (2) is first heated to 600℃ at a heating rate of 5℃ / min and held for 30-33min. Then it is sintered in an argon atmosphere sintering furnace. After sintering, it is first cooled to 1000℃ at a cooling rate of 2℃ / min and then naturally cooled to room temperature with the furnace to obtain high temperature resistant special ceramics.

2. A method of making the high temperature resistant specialty ceramic of claim 1, characterized by: It consists of the following steps: (1) Weigh out calcined kaolin, andalusite, tabular corundum, calcite, cerium phosphate, calcium zirconate, yttrium oxide, titanium diboride and gadolinium trioxide in a certain weight ratio and mix them evenly; (2) The high-temperature resistant special ceramic raw materials, zirconium balls and water weighed in step (1) are added to a ball mill jar for wet ball milling. The resulting slurry is then sieved once, vacuum dried, sieved twice and granulated to prepare powder. The powder is then isostatically pressed to prepare green body. (3) The green body prepared in step (2) is first heated to 600℃ at a heating rate of 5℃ / min and held for 30-33min. Then it is sintered in an argon atmosphere sintering furnace. After sintering, it is first cooled to 1000℃ at a cooling rate of 2℃ / min and then naturally cooled to room temperature with the furnace to obtain high temperature resistant special ceramics.

3. The method of claim 2, wherein the method further comprises: In step (2), the mass ratio of the high-temperature resistant special ceramic raw material, zirconium balls, and water is 1:1.7:0.

8.

4. The method of claim 2, wherein the method further comprises: In step (2), the wet ball milling speed is 250-300 r / min and the ball milling time is 24 h.

5. The method of claim 2, wherein the method further comprises: In step (2), the obtained slurry is sieved once through a 200-mesh sieve, vacuum dried at 85°C, and then sieved a second time through an 80-mesh sieve before granulation.

6. The method of making high temperature resistant specialty ceramic according to claim 2, wherein: In step (2), the isostatic pressing pressure is 250 MPa and the isostatic pressing time is 3 min.

7. The method of making high temperature resistant specialty ceramic according to claim 2, wherein: The sintering process described in step (3) involves first heating the temperature to 900℃ at a rate of 2℃ / min and holding it for 80-90 min, then heating the temperature to 1350℃ at a rate of 4℃ / min and holding it for 60-65 min, and finally heating the temperature to 1700-1720℃ at a rate of 5℃ / min and holding it for 2.5 h.

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