Densified anti-permeation zirconium oxide refractory part and manufacturing method thereof

Abstract

The invention belongs to the technical field of zirconium oxide refractory parts, and particularly relates to a densified anti-permeation zirconium oxide refractory part and a manufacturing method thereof. According to the scheme, raw materials with specific components and dosage are selected and subjected to the steps of pretreatment, mixing, filling forming, sintering, aftertreatment and the like. Through gradient structure design, grain boundary regulation and control and surface defect repair, the prepared zirconia refractory part has high volume density (larger than or equal to 5.76 g / cm), low apparent porosity (smaller than or equal to 0.36%), high bending strength (larger than or equal to 535 MPa) and excellent molten glass permeability resistance (the erosion depth is smaller than or equal to 0.2 mm). Wherein the gradient structure reduces the interface stress and inhibits ZrO phase change, the rare earth oxide is added to form a high-viscosity glass phase to block the diffusion path of erosion ions, the molten salt impregnation process improves the compactness and durability of the material, and the requirement of the modern industry for the high-performance refractory material is met.

Description

Technical Field

[0001] The present invention belongs to the technical field of zirconia refractory products, and particularly relates to a densified anti-permeation zirconia refractory and a manufacturing method thereof. Background Art

[0002] In many high-temperature technological processes of modern industry, refractory materials play an indispensable and crucial role. From blast furnaces and converters in steel smelting, to melting furnaces in glass manufacturing, and then to kilns in ceramic firing and many other devices, they all rely on refractory materials with excellent performance to resist high temperatures, corrosion, erosion, and other harsh working conditions, ensuring the smooth progress of the production process and the service life of the equipment. The performance of refractory materials is directly related to many important aspects such as the efficiency of industrial production, product quality, and energy consumption.

[0003] Zirconia (ZrO 2 ) refractory materials have attracted much attention and been widely used in many fields due to their unique excellent properties. It has extremely high melting point (about 2715 °C), good thermal shock stability, excellent chemical erosion resistance, and relatively high mechanical strength and other characteristics. These characteristics enable it to effectively resist the erosion of high-temperature flames, molten metal or glass liquid, etc. in some extremely harsh high-temperature environments, such as glass melting furnaces, continuous casting tundishes in the steel industry, and high-temperature sintering furnaces in the electronics industry, maintaining the integrity and stability of the structure, thus providing reliable guarantee for related industrial production.

[0004] Although traditional zirconia refractory materials have shown many advantages, with the continuous development and progress of modern industrial technology, the performance requirements for refractory materials are also increasing day by day. There are still some problems to be solved urgently in the common zirconia refractory materials on the market at present. On the one hand, its volume stability at high temperatures still needs to be improved, and microcracks or even spalling are likely to occur during long-term high-temperature use, affecting its service life and reliability. On the other hand, the anti-permeation performance of traditional zirconia refractory materials against materials such as glass melt is not ideal enough, which is likely to cause damage to the internal structure of the material, and then trigger a series of production failures, increasing the maintenance cost and production risk of enterprises.

[0005] To overcome the limitations of the above-mentioned traditional zirconia refractories, the industry has been actively exploring various modification methods and technical means. For example, by adding different oxides or compounds to optimize its microstructure, improve its high-temperature stability and erosion resistance; adopting complex forming processes or sintering techniques to improve the density and uniformity of the material; and surface treatment of the material, etc. However, how to achieve the synergistic improvement of multiple properties, such as simultaneously increasing the bulk density, reducing the apparent porosity, enhancing the flexural strength and the glass melt permeability resistance, etc., remains a challenging issue. In addition, how to ensure the feasibility, economy and stability of its preparation process while improving the material properties is also an important factor that cannot be ignored in actual production. Summary of the Invention

[0006] Aiming at the deficiencies of the existing technology, the present invention provides a densified anti-permeation zirconia refractory piece and its manufacturing method, aiming to prepare a zirconia refractory piece with high bulk density, low apparent porosity, high flexural strength and excellent glass melt permeability resistance, so as to meet the urgent needs of modern industry for high-performance refractories and provide a more reliable, durable and cost-effective refractory material solution for industrial production.

[0007] The first aspect of the present invention is to provide a manufacturing method of a densified anti-permeation zirconia refractory piece, including:

[0008] Select basic powder raw materials including the following components and dosages:

[0009]

[0010] Pretreat the raw materials:

[0011] Grind zirconia, single crystal alumina, fused silica powder, boron compound and rare earth oxide to a preset particle size respectively; calcine silicon carbide whiskers to remove surface impurities and then perform surface modification treatment with a silane coupling agent to improve the dispersibility;

[0012] Mix the raw materials:

[0013] The matrix layer mixture is composed of zirconia, single crystal alumina, fused silica powder, boron compound, rare earth oxide, silicon carbide whiskers, nano-alumina and nano-zirconia mixed according to the formula amount;

[0014] On the basis of the matrix layer formula, the surface layer mixture is additionally added with 3-8% by mass of nano-Y 2 O 6 Si 2 O 7 powder;

[0015] Load and form the raw materials:

[0016] Fill the mold with the matrix layer mixture, with a thickness of 90 - 95% of the total thickness, and then fill it with the surface layer mixture, with a thickness of 5 - 10% of the total thickness; after filling, perform cold isostatic pressing to form;

[0017] Sinter the formed green body:

[0018] Pre-sinter the formed green body to remove the binder, then perform gas pressure sintering under a protective atmosphere, and then perform hot isostatic pressing on the sintered green body to further eliminate internal defects and improve the material density;

[0019] Perform post-treatment on the sintered part:

[0020] Perform molten salt impregnation and plasma spraying treatment on the sintered part to obtain a densified and anti-permeable zirconia refractory.

[0021] As a further optimized scheme for the manufacturing method of the above-mentioned densified and anti-permeable zirconia refractory, during the pretreatment of raw materials, grind zirconia, single crystal alumina, fused silica powder, boron compound, and rare earth oxide to a particle size D50 ≤ 0.8 μm respectively, and add 0.2% of polyacrylic acid by mass of the powder as a dispersant during the grinding process; during the surface modification treatment of silicon carbide whiskers with a silane coupling agent, the concentration of the silane coupling agent used is 2 - 5%, and the dosage is 5 - 8% of the mass of silicon carbide whiskers.

[0022] As a further optimized scheme for the manufacturing method of the above-mentioned densified and anti-permeable zirconia refractory, when preparing the surface layer mixture, on the basis of the matrix layer formula, additionally add 5% by mass of nano - Y 2 O 6 Si 2 O 7 powder.

[0023] As a further optimized scheme for the manufacturing method of the above-mentioned densified and anti-permeable zirconia refractory, when preparing the matrix layer mixture, add a magnesium dihydrogen phosphate solution with a concentration of 15 - 20% during the mixing process, and the addition amount of the magnesium dihydrogen phosphate solution is 10 - 20% of the total mass of the raw materials; when preparing the surface layer mixture, add a magnesium dihydrogen phosphate solution with a concentration of 15 - 20% during the mixing process, and the addition amount of the magnesium dihydrogen phosphate solution is 10 - 20% of the total mass of the raw materials.

[0024] As a further optimized scheme for the manufacturing method of the above-mentioned densified and anti-permeable zirconia refractory, during the raw material filling and forming process, the cold isostatic pressing pressure is 250 - 350 MPa, and the pressure holding time is 2 - 5 minutes.

[0025] As a further optimized solution for the manufacturing method of the above-mentioned densified anti-permeation zirconia refractory, during the sintering process of the formed green body, the formed green body is pre-sintered at 780 - 820 °C for 1 - 5 hours with a heating rate of 2 - 4 °C / min to remove the binder; subsequently, it is subjected to gas pressure sintering at 1600 - 1700 °C for 1 - 3 hours, nitrogen gas with a pressure of 8 - 12 MPa is introduced, and the heating rate is 4 - 6 °C / min; then the sintered green body is subjected to hot isostatic pressing treatment in an argon environment at 1400 - 1600 °C and 120 - 180 MPa for 0.8 - 1.5 hours, and the cooling rate is controlled at ≤5 °C / min to further eliminate internal defects and improve the material density.

[0026] As a further optimized solution for the manufacturing method of the above-mentioned densified anti-permeation zirconia refractory, the oxygen content in the atmosphere used for pre-sintering and gas pressure sintering is ≤10 ppm.

[0027] As a further optimized solution for the manufacturing method of the above-mentioned densified anti-permeation zirconia refractory, during the post-treatment process of the sintered part, the sintered part is immersed in molten borosilicate glass at 1200 - 1250 °C for 25 - 40 minutes to fill the surface pores; after impregnation, it is naturally cooled and the residual glass phase on the surface is removed.

[0028] As a further optimized solution for the manufacturing method of the above-mentioned densified anti-permeation zirconia refractory, during the post-treatment process of the sintered part, after molten salt impregnation, a 30 - 50 μm thick Al 2 O 3 -YAG composite coating is deposited on the surface by plasma spraying.

[0029] The second aspect of the present invention is to provide a densified anti-permeation zirconia refractory, which is prepared according to the above manufacturing method.

[0030] Beneficial effects

[0031] Through gradient structure design, grain boundary regulation, and surface defect repair, the present invention significantly improves the comprehensive performance of the zirconia refractory. The obtained zirconia refractory has a high bulk density (≥5.76 g / cm 3 ), a low apparent porosity (≤0.36%), a high flexural strength (≥535 MPa), and excellent glass melt permeability resistance (erosion depth ≤0.2 mm). Among them, the gradient structure effectively reduces the interfacial stress and inhibits the ZrO 2 phase transformation, and the addition of rare earth oxides forms a high-viscosity glass phase, blocking the diffusion path of erosion ions and further enhancing the erosion resistance of the material. In addition, the molten salt impregnation process significantly reduces the surface open porosity and improves the density and durability of the material. Specific embodiments

[0032] The present invention will be further illustrated by specific embodiments below. These embodiments are exemplary and are intended to illustrate the problem and explain the present invention, rather than being a limitation.

[0033] (1) Raw materials and their specifications

[0034] Table 1 Raw materials and specifications

[0035]

[0036]

[0037] (2) Basic powder raw materials and their dosages

[0038]

[0039] (3) Preparation process steps

[0040] 1. Raw material pretreatment

[0041] The raw material pretreatment includes grinding, screening, and surface treatment of silicon carbide whiskers. First, zirconia, single-crystal alumina, fused silica powder, boron compounds, and rare earth oxides are respectively ground to the target particle size (D50 ≤ 0.8 μm). High-energy ball milling is used for grinding and dispersion treatment. The ball mill speed is 300 rpm, the ball-to-material ratio is 5:1, and 0.2% of polyacrylic acid is added as a dispersant. The ball milling time is 4 hours. All raw materials need to be sieved after grinding to ensure uniform particle size. For silicon carbide whiskers, they are first calcined at 800 °C for 2 hours to remove surface impurities, and then surface modification treatment is carried out using a silane coupling agent (KH550) to improve their dispersibility in the subsequent mixing process. The concentration of the silane coupling agent is 2 - 5% (mass fraction), and the dosage is 5 - 8% of the mass of silicon carbide whiskers.

[0042] 2. Mixing raw materials

[0043] The mixing of raw materials is divided into the preparation of the matrix layer mixture and the surface layer mixture. The matrix layer mixture is composed of zirconia, single-crystal alumina, fused silica powder, boron compounds, rare earth oxides, silicon carbide whiskers, nano-alumina, and nano-zirconia mixed according to the formula amount. During the mixing process, a magnesium dihydrogen phosphate solution with a concentration of 15 - 20% is added. The addition amount of the magnesium dihydrogen phosphate solution is 10 - 20% of the total mass of the raw materials. Wet ball milling is carried out for 6 hours to form a uniform slurry. After the slurry is dried at 80 °C for 12 hours, it is sieved through a 100-mesh sieve and reserved for use.

[0044] On the basis of the matrix layer formula, the surface layer mixture additionally adds 5% by mass of nano-Y 2 O 6 Si 2 O 7Powder, during the mixing process, add a magnesium dihydrogen phosphate solution with a concentration of 15 - 20%, and the addition amount of the magnesium dihydrogen phosphate solution is 10 - 20% of the total mass of the raw materials. Use wet ball milling for 6 hours to form a uniform slurry. After drying the slurry at 80°C for 12 hours, pass it through a 100-mesh sieve for standby.

[0045] 3. Molding

[0046] The molding process uses the technologies of layered filling and cold isostatic pressing. First, fill the matrix layer mixture in the mold, with a thickness of 90 - 95% of the total thickness, and then fill the surface layer mixture, with a thickness of 5 - 10% of the total thickness. After the filling is completed, use cold isostatic pressing, with a pressure of 300 MPa and a pressure holding time of 3 minutes to ensure the density and uniformity of the green body.

[0047] 4. Sintering

[0048] The sintering process includes three steps: pre-sintering, gas pressure sintering, and hot isostatic pressing. First, pre-sinter the molded green body at 800°C for 2 hours, with a heating rate of 3°C / min to remove the binder. Subsequently, conduct gas pressure sintering at 1600 - 1700°C for 2 hours, introduce nitrogen with a pressure of 10 MPa, and the heating rate is 5°C / min. Finally, perform hot isostatic pressing on the sintered green body in an argon environment at 1500°C and 150 MPa for 1 hour, and control the cooling rate to ≤5°C / min to further eliminate internal defects and improve the material density. The atmosphere for pre-sintering and gas pressure sintering uses high-purity inert gas (nitrogen or argon), and the oxygen content ≤10 ppm.

[0049] 5. Post-treatment

[0050] The post-treatment includes two steps: molten salt impregnation and plasma spraying. First, immerse the sintered part in molten borosilicate glass at 1200 - 1250°C for 30 minutes to fill the surface pores. After the impregnation is completed, cool it naturally and remove the residual glass phase on the surface. Subsequently, use plasma spraying technology to deposit an Al 2 O 3 -YAG composite coating with a thickness of 30 - 50 μm on the surface. The spraying parameters are: current 500 A, gas flow rate Ar / H 2 = 45 / 15 SLPM, spraying distance 80 mm, spraying speed 200 mm / s. A densified anti-permeation zirconia refractory piece is obtained.

[0051] Example 1

[0052] Basic powder raw materials and their dosages

[0053]

[0054] 1. Raw material pretreatment

[0055] The raw material pretreatment includes grinding, screening, and surface treatment of silicon carbide whiskers. First, zirconia, single-crystal alumina, fused silica powder, boron compounds, and rare earth oxides are respectively ground to the target particle size (D50 ≤ 0.8 μm). High-energy ball milling is used for grinding and dispersion treatment. The ball mill rotates at 300 rpm, the ball-to-material ratio is 5:1, and 0.2% polyacrylic acid is added as a dispersant. The ball milling time is 4 hours. All raw materials need to be sieved after grinding to ensure uniform particle size. For silicon carbide whiskers, they are first calcined at 800 °C for 2 hours to remove surface impurities, and then surface modification treatment is carried out using a silane coupling agent (KH550) to improve their dispersibility in the subsequent mixing process. The concentration of the silane coupling agent is 2% (mass fraction), and the dosage is 5% of the mass of silicon carbide whiskers.

[0056] 2. Mixing Raw Materials

[0057] The mixing of raw materials is divided into the preparation of the matrix layer mixture and the surface layer mixture. The matrix layer mixture is composed of zirconia, single-crystal alumina, fused silica powder, boron compounds, rare earth oxides, silicon carbide whiskers, nano-alumina, and nano-zirconia mixed according to the formula amount. During the mixing process, a 18% magnesium dihydrogen phosphate solution is added, and the addition amount of the magnesium dihydrogen phosphate solution is 15% of the total mass of the raw materials. Wet ball milling is carried out for 6 hours to form a uniform slurry. After the slurry is dried at 80 °C for 12 hours, it is sieved through a 100-mesh sieve for standby.

[0058] On the basis of the matrix layer formula, the surface layer mixture is additionally added with 5% by mass of nano-Y 2 O 6 Si 2 O 7 powder. During the mixing process, a 18% magnesium dihydrogen phosphate solution is added, and the addition amount of the magnesium dihydrogen phosphate solution is 15% of the total mass of the raw materials. Wet ball milling is carried out for 6 hours to form a uniform slurry. After the slurry is dried at 80 °C for 12 hours, it is sieved through a 100-mesh sieve for standby.

[0059] 3. Molding

[0060] The molding process uses the layered filling and cold isostatic pressing molding technology. First, the matrix layer mixture is filled into the mold, with a thickness of 90% of the total thickness. Subsequently, the surface layer mixture is filled, with a thickness of 10% of the total thickness. After filling, cold isostatic pressing is carried out at a pressure of 300 MPa and a holding pressure time of 3 minutes to ensure the density and uniformity of the green body.

[0061] 4. Sintering

[0062] The sintering process includes three steps: pre-sintering, gas-pressure sintering, and hot isostatic pressing. First, the formed green body is pre-sintered at 800 °C for 2 hours with a heating rate of 3 °C / min to remove the binder. Subsequently, it is gas-pressure sintered at 1600 °C for 2 hours while introducing nitrogen gas at 10 MPa with a heating rate of 5 °C / min. Finally, the sintered green body is subjected to hot isostatic pressing treatment in an argon environment at 1500 °C and 150 MPa for 1 hour, and the cooling rate is controlled at ≤5 °C / min to further eliminate internal defects and improve the material density. High-purity inert gas (nitrogen or argon) is used as the atmosphere for pre-sintering and gas-pressure sintering, and the oxygen content is ≤10 ppm.

[0063] 5. Post-treatment

[0064] The post-treatment includes two steps: molten salt impregnation and plasma spraying. First, the sintered part is immersed in molten borosilicate glass at 1200 °C for 30 minutes to fill the surface pores. After impregnation, it is naturally cooled and the residual glass phase on the surface is removed. Subsequently, a 30-μm Al 2 O 3 -YAG composite coating is deposited on the surface by plasma spraying. The spraying parameters are: current 500 A, gas flow rate Ar / H 2 = 45 / 15 SLPM, spraying distance 80 mm, spraying speed 200 mm / s. A densified anti-permeation zirconia refractory is obtained.

[0065] Example 2

[0066] Base powder raw materials and their dosages

[0067]

[0068]

[0069] 1. Raw material pretreatment

[0070] The raw material pretreatment includes grinding, screening, and surface treatment of silicon carbide whiskers. First, zirconia, single crystal alumina, fused silica powder, boron compounds, and rare earth oxides are respectively ground to the target particle size (D50 ≤ 0.8 μm). High-energy ball milling is used for grinding and dispersion treatment. The ball mill speed is 300 rpm, the ball-to-material ratio is 5:1, and 0.2% polyacrylic acid is added as a dispersant. The ball milling time is 4 hours. All raw materials need to be sieved after grinding to ensure uniform particle size. For silicon carbide whiskers, they are first calcined at 800 °C for 2 hours to remove surface impurities, and then surface modification treatment is carried out using a silane coupling agent (KH550) to improve their dispersibility in the subsequent mixing process. The concentration of the silane coupling agent is 5% (mass fraction), and the dosage is 8% of the mass of the silicon carbide whiskers.

[0071] 2. Mixed Raw Materials

[0072] The preparation of the mixed raw materials is divided into that of the matrix layer mixture and the surface layer mixture. The matrix layer mixture is formed by mixing zirconia, single crystal alumina, fused silica powder, boron compound, rare earth oxide, silicon carbide whiskers, nano-alumina and nano-zirconia according to the formula amounts. During the mixing process, a 18% magnesium dihydrogen phosphate solution is added, and the addition amount of the magnesium dihydrogen phosphate solution is 15% of the total mass of the raw materials. Wet ball milling is carried out for 6 hours to form a uniform slurry. After the slurry is dried at 80°C for 12 hours, it is sieved through a 100-mesh sieve and reserved for use.

[0073] On the basis of the matrix layer formula, the surface layer mixture is additionally added with 5% by mass of nano-Y 2 O 6 Si 2 O 7 powder. During the mixing process, a 18% magnesium dihydrogen phosphate solution is added, and the addition amount of the magnesium dihydrogen phosphate solution is 15% of the total mass of the raw materials. Wet ball milling is carried out for 6 hours to form a uniform slurry. After the slurry is dried at 80°C for 12 hours, it is sieved through a 100-mesh sieve and reserved for use.

[0074] 3. Molding

[0075] The molding process adopts the techniques of layered filling and cold isostatic pressing. First, the matrix layer mixture is filled into the mold with a thickness of 95% of the total thickness, and then the surface layer mixture is filled with a thickness of 5% of the total thickness. After the filling is completed, cold isostatic pressing is carried out at a pressure of 300 MPa and a holding time of 3 minutes to ensure the density and uniformity of the green body.

[0076] 4. Sintering

[0077] The sintering process includes three steps: pre-sintering, gas pressure sintering and hot isostatic pressing. First, the molded green body is pre-sintered at 800°C for 2 hours with a heating rate of 3°C / min to remove the binder. Subsequently, gas pressure sintering is carried out at 1700°C for 2 hours, and nitrogen with a pressure of 10 MPa is introduced with a heating rate of 5°C / min. Finally, the sintered green body is subjected to hot isostatic pressing treatment at 1500°C and 150 MPa in an argon atmosphere for 1 hour, and the cooling rate is controlled at ≤5°C / min to further eliminate internal defects and improve the material density. The atmosphere for pre-sintering and gas pressure sintering uses high-purity inert gas (nitrogen or argon) with an oxygen content of ≤10 ppm.

[0078] 5. Post-treatment

[0079] The post-treatment includes two steps: molten salt impregnation and plasma spraying. First, the sintered parts are immersed in molten borosilicate glass at 1250 °C for 30 minutes to fill the surface pores. After impregnation, they are naturally cooled and the residual glass phase on the surface is removed. Subsequently, a 50-μm Al 2 O 3 -YAG composite coating is deposited on the surface by plasma spraying. The spraying parameters are: current 500 A, gas flow rate Ar / H 2 = 45 / 15 SLPM, spraying distance 80 mm, spraying speed 200 mm / s. A densified and anti-permeable zirconia refractory is obtained.

[0080] Example 3

[0081] Base powder raw materials and their dosages

[0082]

[0083] 1. Raw material pretreatment

[0084] The raw material pretreatment includes grinding, screening, and surface treatment of silicon carbide whiskers. First, zirconia, single crystal alumina, fused silica powder, boron compounds, and rare earth oxides are respectively ground to the target particle size (D50 ≤ 0.8 μm). High-energy ball milling is used for grinding and dispersion treatment. The ball mill speed is 300 rpm, the ball-to-material ratio is 5:1, and 0.2% polyacrylic acid is added as a dispersant. The ball milling time is 4 hours. All raw materials need to be screened after grinding to ensure uniform particle size. For silicon carbide whiskers, they are first calcined at 800 °C for 2 hours to remove surface impurities, and then surface modification treatment is carried out using a silane coupling agent (KH550) to improve their dispersibility in the subsequent mixing process. The concentration of the silane coupling agent is 5% (mass fraction), and the dosage is 5% of the mass of the silicon carbide whiskers.

[0085] 2. Mixing raw materials

[0086] The mixing of raw materials is divided into the preparation of the matrix layer mixture and the surface layer mixture. The matrix layer mixture is composed of zirconia, single crystal alumina, fused silica powder, boron compounds, rare earth oxides, silicon carbide whiskers, nano-alumina, and nano-zirconia mixed according to the formula amount. During the mixing process, a 15% magnesium dihydrogen phosphate solution is added, and the addition amount of the magnesium dihydrogen phosphate solution is 20% of the total mass of the raw materials. Wet ball milling is carried out for 6 hours to form a uniform slurry. After the slurry is dried at 80 °C for 12 hours, it is sieved through a 100-mesh sieve and reserved for use.

[0087] On the basis of the matrix layer formula, the surface layer mixture is additionally added with 5% by mass of nano-Y 2 O 6 Si 2 O 7Powder, during the mixing process, add a magnesium dihydrogen phosphate solution with a concentration of 20%, and the addition amount of the magnesium dihydrogen phosphate solution is 20% of the total mass of the raw materials. Use wet ball milling for 6 hours to form a uniform slurry. After drying the slurry at 80 °C for 12 hours, pass it through a 100-mesh sieve for standby.

[0088] 3. Molding

[0089] The molding process uses the techniques of layered filling and cold isostatic pressing. First, fill the matrix layer mixture into the mold, with a thickness of 90% of the total thickness, and then fill the surface layer mixture, with a thickness of 10% of the total thickness. After filling, use cold isostatic pressing, with a pressure of 300 MPa and a pressure holding time of 3 minutes, to ensure the density and uniformity of the green body.

[0090] 4. Sintering

[0091] The sintering process includes three steps: pre-sintering, gas pressure sintering, and hot isostatic pressing. First, pre-sinter the formed green body at 800 °C for 2 hours, with a heating rate of 3 °C / min to remove the binder. Subsequently, perform gas pressure sintering at 1650 °C for 2 hours, introduce nitrogen with a pressure of 10 MPa, and the heating rate is 5 °C / min. Finally, perform hot isostatic pressing on the sintered green body in an argon atmosphere at 1500 °C and 150 MPa for 1 hour, and control the cooling rate to ≤5 °C / min to further eliminate internal defects and improve the material density. The atmosphere for pre-sintering and gas pressure sintering uses high-purity inert gas (nitrogen or argon), and the oxygen content ≤10 ppm.

[0092] 5. Post-treatment

[0093] The post-treatment includes two steps: molten salt impregnation and plasma spraying. First, immerse the sintered part in molten borosilicate glass at 1250 °C for 30 minutes to fill the surface pores. After impregnation, cool it naturally and remove the residual glass phase on the surface. Subsequently, use plasma spraying technology to deposit a 50-μm Al 2 O 3 -YAG composite coating, and the spraying parameters are: current 500 A, gas flow rate Ar / H 2 = 45 / 15 SLPM, spraying distance 80 mm, spraying speed 200 mm / s. A densified anti-permeation zirconia refractory is prepared.

[0094] Example 4

[0095] Base powder raw materials and their dosages

[0096]

[0097] 1. Raw material pretreatment

[0098] The raw material pretreatment includes grinding, screening, and surface treatment of silicon carbide whiskers. First, zirconia, single-crystal alumina, fused silica powder, boron compounds, and rare earth oxides are respectively ground to the target particle size (D50 ≤ 0.8 μm). High-energy ball milling is used for grinding and dispersion treatment. The ball mill rotates at 300 rpm, the ball-to-material ratio is 5:1, and 0.2% polyacrylic acid is added as a dispersant. The ball milling time is 4 hours. All raw materials need to be screened after grinding to ensure uniform particle size. For silicon carbide whiskers, they are first calcined at 800 °C for 2 hours to remove surface impurities, and then surface modification treatment is carried out using a silane coupling agent (KH550) to improve their dispersibility in the subsequent mixing process. The concentration of the silane coupling agent is 5% (mass fraction), and the dosage is 5% of the mass of the silicon carbide whiskers.

[0099] 2. Mixing the raw materials

[0100] The mixing of raw materials is divided into the preparation of the matrix layer mixture and the surface layer mixture. The matrix layer mixture is composed of zirconia, single-crystal alumina, fused silica powder, boron compounds, rare earth oxides, silicon carbide whiskers, nano-alumina, and nano-zirconia mixed according to the formula amount. During the mixing process, a 15% magnesium dihydrogen phosphate solution is added, and the addition amount of the magnesium dihydrogen phosphate solution is 10% of the total mass of the raw materials. Wet ball milling is carried out for 6 hours to form a uniform slurry. After the slurry is dried at 80 °C for 12 hours, it is screened through a 100-mesh sieve and reserved for use.

[0101] On the basis of the matrix layer formula, the surface layer mixture additionally adds 5% by mass of nano-Y 2 O 6 Si 2 O 7 powder. During the mixing process, a 20% magnesium dihydrogen phosphate solution is added, and the addition amount of the magnesium dihydrogen phosphate solution is 20% of the total mass of the raw materials. Wet ball milling is carried out for 6 hours to form a uniform slurry. After the slurry is dried at 80 °C for 12 hours, it is screened through a 100-mesh sieve and reserved for use.

[0102] 3. Shaping

[0103] The shaping process adopts the techniques of layered filling and cold isostatic pressing. First, the matrix layer mixture is filled into the mold, with a thickness of 95% of the total thickness, and then the surface layer mixture is filled, with a thickness of 5% of the total thickness. After the filling is completed, cold isostatic pressing is carried out at a pressure of 300 MPa and a holding pressure time of 3 minutes to ensure the density and uniformity of the green body.

[0104] 4. Sintering

[0105] The sintering process includes three steps: pre-sintering, gas pressure sintering, and hot isostatic pressing. First, the formed green body is pre-sintered at 800 °C for 2 hours with a heating rate of 3 °C / min to remove the binder. Subsequently, it is gas pressure sintered at 1600 °C for 2 hours with nitrogen gas of 10 MPa introduced and a heating rate of 5 °C / min. Finally, the sintered green body is subjected to hot isostatic pressing in an argon environment at 1500 °C and 150 MPa for 1 hour, and the cooling rate is controlled at ≤5 °C / min to further eliminate internal defects and improve the material density. High-purity inert gas (nitrogen or argon) is used as the atmosphere for pre-sintering and gas pressure sintering, with an oxygen content of ≤10 ppm.

[0106] 5. Post-treatment

[0107] The post-treatment includes two steps: molten salt impregnation and plasma spraying. First, the sintered part is immersed in molten borosilicate glass at 1250 °C for 30 minutes to fill the surface pores. After impregnation, it is naturally cooled and the residual glass phase on the surface is removed. Subsequently, a 30-μm Al 2 O 3 -YAG composite coating is deposited on the surface by plasma spraying. The spraying parameters are: current 500 A, gas flow rate Ar / H 2 = 45 / 15 SLPM, spraying distance 80 mm, spraying speed 200 mm / s. A densified anti-permeation zirconia refractory piece is obtained.

[0108] Example 5

[0109] Base powder raw materials and their dosages

[0110]

[0111] 1. Raw material pretreatment

[0112] The raw material pretreatment includes grinding, screening, and surface treatment of silicon carbide whiskers. First, zirconia, single crystal alumina, fused silica powder, boron compound, and rare earth oxide are respectively ground to the target particle size (D50 ≤ 0.8 μm). High-energy ball milling is used for grinding and dispersion treatment. The ball mill speed is 300 rpm, the ball-to-material ratio is 5:1, and 0.2% polyacrylic acid is added as a dispersant. The ball milling time is 4 hours. All raw materials need to be screened after grinding to ensure uniform particle size. For silicon carbide whiskers, they are first calcined at 800 °C for 2 hours to remove surface impurities, and then surface modification treatment is carried out using a silane coupling agent (KH550) to improve their dispersibility in the subsequent mixing process. The concentration of the silane coupling agent is 2% (mass fraction), and the dosage is 5% of the mass of the silicon carbide whiskers.

[0113] 2. Mixing raw materials

[0114] The preparation of the mixed raw materials is divided into the preparation of the matrix layer mixture and the surface layer mixture. The matrix layer mixture is composed of zirconia, single crystal alumina, fused silica powder, boron compound, rare earth oxide, silicon carbide whiskers, nano-alumina and nano-zirconia mixed according to the formula amount. During the mixing process, a 15% magnesium dihydrogen phosphate solution is added, and the addition amount of the magnesium dihydrogen phosphate solution is 10% of the total mass of the raw materials. Wet ball milling is carried out for 6 hours to form a uniform slurry. After the slurry is dried at 80 °C for 12 hours, it is sieved through a 100-mesh sieve for standby.

[0115] On the basis of the matrix layer formula, the surface layer mixture is additionally added with 5% by mass of nano-Y 2 O 6 Si 2 O 7 powder. During the mixing process, a 15% magnesium dihydrogen phosphate solution is added, and the addition amount of the magnesium dihydrogen phosphate solution is 10% of the total mass of the raw materials. Wet ball milling is carried out for 6 hours to form a uniform slurry. After the slurry is dried at 80 °C for 12 hours, it is sieved through a 100-mesh sieve for standby.

[0116] 3. Molding

[0117] The molding process adopts the technologies of layered filling and cold isostatic pressing. First, the matrix layer mixture is filled into the mold with a thickness of 95% of the total thickness, and then the surface layer mixture is filled with a thickness of 5% of the total thickness. After the filling is completed, cold isostatic pressing is carried out at a pressure of 300 MPa and a pressure holding time of 3 minutes to ensure the density and uniformity of the green body.

[0118] 4. Sintering

[0119] The sintering process includes three steps: pre-sintering, gas pressure sintering and hot isostatic pressing. First, the formed green body is pre-sintered at 800 °C for 2 hours with a heating rate of 3 °C / min to remove the binder. Subsequently, gas pressure sintering is carried out at 1700 °C for 2 hours, and nitrogen with a pressure of 10 MPa is introduced with a heating rate of 5 °C / min. Finally, the sintered green body is subjected to hot isostatic pressing treatment at 1500 °C and 150 MPa in an argon atmosphere for 1 hour, and the cooling rate is controlled at ≤5 °C / min to further eliminate internal defects and improve the material density. The atmosphere for pre-sintering and gas pressure sintering uses high-purity inert gas (nitrogen or argon) with an oxygen content of ≤10 ppm.

[0120] 5. Post-treatment

[0121] The post-treatment includes two steps: molten salt impregnation and plasma spraying. First, the sintered part is immersed in molten borosilicate glass at 1200 °C for 30 minutes to fill the surface pores. After the impregnation is completed, it is naturally cooled and the residual glass phase on the surface is removed. Subsequently, a 30-μm Al 2 O 3-YAG composite coating, spraying parameters: current 500 A, gas flow rate Ar / H 2 = 45 / 15 SLPM, spraying distance 80 mm, spraying speed 200 mm / s. A densified anti-permeation zirconia refractory was prepared.

[0122] Example 6

[0123] Base powder raw materials and their dosages

[0124]

[0125] 1. Raw material pretreatment

[0126] The raw material pretreatment includes grinding, screening and surface treatment of silicon carbide whiskers. First, zirconia, single crystal alumina, fused silica powder, boron compound and rare earth oxide are respectively ground to the target particle size (D50 ≤ 0.8 μm). High-energy ball milling is used for grinding and dispersion treatment, the ball mill speed is 300 rpm, the ball-to-material ratio is 5:1, and 0.2% polyacrylic acid is added as a dispersant, and the ball milling time is 4 hours. All raw materials need to be sieved after grinding to ensure uniform particle size. For silicon carbide whiskers, first calcine at 800 °C for 2 hours to remove surface impurities, and then use silane coupling agent (KH550) for surface modification treatment to improve its dispersibility in the subsequent mixing process. The concentration of the silane coupling agent is 2% (mass fraction), and the dosage is 8% of the mass of silicon carbide whiskers.

[0127] 2. Mixing raw materials

[0128] The mixing of raw materials is divided into the preparation of matrix layer mixture and surface layer mixture. The matrix layer mixture is composed of zirconia, single crystal alumina, fused silica powder, boron compound, rare earth oxide, silicon carbide whiskers, nano-alumina and nano-zirconia mixed according to the formula amount. During the mixing process, a 15% magnesium dihydrogen phosphate solution is added, and the addition amount of the magnesium dihydrogen phosphate solution is 10% of the total mass of the raw materials. Wet ball milling is carried out for 6 hours to form a uniform slurry. After the slurry is dried at 80 °C for 12 hours, it is sieved through a 100-mesh sieve and reserved for use.

[0129] On the basis of the matrix layer formula, the surface layer mixture is additionally added with 5% by mass of nano-Y 2 O 6 Si 2 O 7 powder, and a 15% magnesium dihydrogen phosphate solution is added during the mixing process. The addition amount of the magnesium dihydrogen phosphate solution is 10% of the total mass of the raw materials. Wet ball milling is carried out for 6 hours to form a uniform slurry. After the slurry is dried at 80 °C for 12 hours, it is sieved through a 100-mesh sieve and reserved for use.

[0130] 3. Molding

[0131] The forming process adopts the technologies of layered filling and cold isostatic pressing. First, the matrix layer mixture is filled into the mold with a thickness of 90% of the total thickness, and then the surface layer mixture is filled with a thickness of 10% of the total thickness. After filling, cold isostatic pressing is carried out at a pressure of 300 MPa and a pressure holding time of 3 minutes to ensure the density and uniformity of the green body.

[0132] 4. Sintering

[0133] The sintering process includes three steps: pre-sintering, gas pressure sintering and hot isostatic pressing. First, the formed green body is pre-sintered at 800 °C for 2 hours with a heating rate of 3 °C / min to remove the binder. Subsequently, gas pressure sintering is carried out at 1650 °C for 2 hours, introducing nitrogen gas at 10 MPa with a heating rate of 5 °C / min. Finally, the sintered green body is subjected to hot isostatic pressing treatment at 1500 °C and 150 MPa in an argon atmosphere for 1 hour, and the cooling rate is controlled at ≤5 °C / min to further eliminate internal defects and improve the material density. The atmosphere for pre-sintering and gas pressure sintering uses high-purity inert gas (nitrogen or argon) with an oxygen content ≤10 ppm.

[0134] 5. Post-treatment

[0135] The post-treatment includes two steps: molten salt impregnation and plasma spraying. First, the sintered part is immersed in molten borosilicate glass at 1200 °C for 30 minutes to fill the surface pores. After impregnation, it is naturally cooled and the residual glass phase on the surface is removed. Subsequently, a 40-μm Al 2 O 3 -YAG composite coating is deposited on the surface by plasma spraying. The spraying parameters are: current 500 A, gas flow rate Ar / H 2 = 45 / 15 SLPM, spraying distance 80 mm, spraying speed 200 mm / s. A densified anti-permeation zirconia refractory is obtained.

[0136] Comparative Example 1

[0137] Compared with Example 3, in Comparative Example 1, the matrix layer mixture and the surface layer mixture were not distinguished, but the same mixture was used for one-piece forming.

[0138] Base powder raw materials and their dosages

[0139]

[0140] 1. Raw material pretreatment

[0141] The raw material pretreatment includes grinding, screening, and surface treatment of silicon carbide whiskers. First, zirconia, single crystal alumina, fused silica powder, boron compounds, and rare earth oxides are respectively ground to the target particle size (D50 ≤ 0.8 μm). High-energy ball milling is used for grinding and dispersion treatment. The rotational speed of the ball mill is 300 rpm, the ball-to-material ratio is 5:1, and 0.2% of polyacrylic acid is added as a dispersant. The ball milling time is 4 hours. After grinding, all raw materials need to be screened to ensure uniform particle size. For silicon carbide whiskers, they are first calcined at 800 °C for 2 hours to remove surface impurities, and then surface modification treatment is carried out using a silane coupling agent (KH550) to improve their dispersibility in the subsequent mixing process. The concentration of the silane coupling agent is 5% (mass fraction), and the dosage is 5% of the mass of the silicon carbide whiskers.

[0142] 2. Mixing the raw materials

[0143] The mixed raw materials are composed of zirconia, single crystal alumina, fused silica powder, boron compounds, rare earth oxides, silicon carbide whiskers, nano-alumina, and nano-zirconia mixed according to the formula amount. During the mixing process, a 15% magnesium dihydrogen phosphate solution is added, and the addition amount of the magnesium dihydrogen phosphate solution is 20% of the total mass of the raw materials. Wet ball milling is carried out for 6 hours to form a uniform slurry. After the slurry is dried at 80 °C for 12 hours, it is sieved through a 100-mesh sieve and reserved for use.

[0144] 3. Molding

[0145] The mixed material is filled into the mold. After filling, cold isostatic pressing is carried out at a pressure of 300 MPa and a pressure holding time of 3 minutes to ensure the density and uniformity of the green body.

[0146] 4. Sintering

[0147] The sintering process includes three steps: pre-sintering, gas pressure sintering, and hot isostatic pressing. First, the formed green body is pre-sintered at 800 °C for 2 hours with a heating rate of 3 °C / min to remove the binder. Subsequently, gas pressure sintering is carried out at 1650 °C for 2 hours, and nitrogen with a pressure of 10 MPa is introduced, with a heating rate of 5 °C / min. Finally, the sintered green body is subjected to hot isostatic pressing treatment at 1500 °C and 150 MPa in an argon atmosphere for 1 hour, and the cooling rate is controlled at ≤ 5 °C / min to further eliminate internal defects and improve the material density. The atmosphere for pre-sintering and gas pressure sintering uses high-purity inert gas (nitrogen or argon), and the oxygen content is ≤ 10 ppm.

[0148] 5. Post-treatment

[0149] The post-treatment includes two steps: molten salt impregnation and plasma spraying. First, the sintered parts are immersed in molten borosilicate glass at 1250 °C for 30 minutes to fill the surface pores. After impregnation, they are naturally cooled and the residual glass phase on the surface is removed. Subsequently, a 50-μm Al 2 O 3 -YAG composite coating is deposited on the surface by plasma spraying. The spraying parameters are: current 500 A, gas flow rate Ar / H 2 = 45 / 15 SLPM, spraying distance 80 mm, spraying speed 200 mm / s. A densified and anti-permeable zirconia refractory is obtained.

[0150] Comparative Example 2

[0151] In Comparative Example 2 compared with Example 3, rare earth oxides were not added to the raw materials.

[0152] Base powder raw materials and their dosages

[0153]

[0154] 1. Raw material pretreatment

[0155] The raw material pretreatment includes grinding, screening, and surface treatment of silicon carbide whiskers. First, zirconia, single-crystal alumina, fused silica powder, and boron compounds are respectively ground to the target particle size (D50 ≤ 0.8 μm). High-energy ball milling is used for grinding and dispersion treatment. The ball mill speed is 300 rpm, the ball-to-material ratio is 5:1, and 0.2% polyacrylic acid is added as a dispersant. The ball milling time is 4 hours. All raw materials need to be sieved after grinding to ensure uniform particle size. For silicon carbide whiskers, they are first calcined at 800 °C for 2 hours to remove surface impurities, and then surface modification treatment is carried out using a silane coupling agent (KH550) to improve their dispersibility in the subsequent mixing process. The concentration of the silane coupling agent is 5% (mass fraction), and the dosage is 5% of the mass of the silicon carbide whiskers.

[0156] 2. Mixing raw materials

[0157] The mixing of raw materials is divided into the preparation of the matrix layer mixture and the surface layer mixture. The matrix layer mixture is composed of zirconia, single-crystal alumina, fused silica powder, boron compounds, silicon carbide whiskers, nano-alumina, and nano-zirconia mixed according to the formula amount. During the mixing process, a 15% magnesium dihydrogen phosphate solution is added, and the addition amount of the magnesium dihydrogen phosphate solution is 20% of the total mass of the raw materials. Wet ball milling is carried out for 6 hours to form a uniform slurry. After the slurry is dried at 80 °C for 12 hours, it is sieved through a 100-mesh sieve and reserved for use.

[0158] On the basis of the matrix layer formula, the surface layer mixture is additionally added with 5% by mass of nano-Y 2 O 6 Si2 O 7 Powder, during the mixing process, add a magnesium dihydrogen phosphate solution with a concentration of 20%, and the addition amount of the magnesium dihydrogen phosphate solution is 20% of the total mass of the raw materials. Use wet ball milling for 6 hours to form a uniform slurry. After drying the slurry at 80°C for 12 hours, pass it through a 100-mesh sieve for standby.

[0159] 3. Forming

[0160] The forming process uses the techniques of layered filling and cold isostatic pressing. First, fill the matrix layer mixture in the mold, with a thickness of 90% of the total thickness, and then fill the surface layer mixture, with a thickness of 10% of the total thickness. After filling, use cold isostatic pressing with a pressure of 300 MPa and a pressure holding time of 3 minutes to ensure the density and uniformity of the green body.

[0161] 4. Sintering

[0162] The sintering process includes three steps: pre-sintering, gas pressure sintering, and hot isostatic pressing. First, pre-sinter the formed green body at 800°C for 2 hours with a heating rate of 3°C / min to remove the binder. Subsequently, perform gas pressure sintering at 1650°C for 2 hours, introduce nitrogen with a pressure of 10 MPa, and the heating rate is 5°C / min. Finally, perform hot isostatic pressing on the sintered green body in an argon environment at 1500°C and 150 MPa for 1 hour, and control the cooling rate at ≤5°C / min to further eliminate internal defects and improve the material density. The atmosphere for pre-sintering and gas pressure sintering uses high-purity inert gas (nitrogen or argon) with an oxygen content of ≤10 ppm.

[0163] 5. Post-treatment

[0164] The post-treatment includes two steps: molten salt impregnation and plasma spraying. First, immerse the sintered part in molten borosilicate glass at 1250°C for 30 minutes to fill the surface pores. After impregnation, cool naturally and remove the residual glass phase on the surface. Subsequently, use plasma spraying technology to deposit a 50-μm Al 2 O 3 -YAG composite coating, and the spraying parameters are: current 500 A, gas flow rate Ar / H 2 = 45 / 15 SLPM, spraying distance 80 mm, spraying speed 200 mm / s. A densified anti-permeation zirconia refractory is prepared.

[0165] Comparative Example 3

[0166] Comparative Example 3 compared with Example 3 omits the molten salt impregnation step in the post-treatment process.

[0167] Basic powder raw materials and their dosages

[0168]

[0169] 1. Raw material pretreatment

[0170] The raw material pretreatment includes grinding, screening, and surface treatment of silicon carbide whiskers. First, zirconia, single-crystal alumina, fused silica powder, boron compounds, and rare earth oxides are respectively ground to the target particle size (D50 ≤ 0.8 μm). High-energy ball milling is used for grinding and dispersion treatment. The ball mill rotates at 300 rpm, the ball-to-material ratio is 5:1, and 0.2% of polyacrylic acid is added as a dispersant. The ball milling time is 4 hours. All raw materials need to be screened after grinding to ensure uniform particle size. For silicon carbide whiskers, they are first calcined at 800 °C for 2 hours to remove surface impurities, and then surface modification treatment is carried out using a silane coupling agent (KH550) to improve their dispersibility in the subsequent mixing process. The concentration of the silane coupling agent is 5% (mass fraction), and the dosage is 5% of the mass of the silicon carbide whiskers.

[0171] 2. Mixing raw materials

[0172] The mixing of raw materials is divided into the preparation of the matrix layer mixture and the surface layer mixture. The matrix layer mixture is composed of zirconia, single-crystal alumina, fused silica powder, boron compounds, rare earth oxides, silicon carbide whiskers, nano-alumina, and nano-zirconia mixed according to the formula amount. During the mixing process, a 15% magnesium dihydrogen phosphate solution is added, and the addition amount of the magnesium dihydrogen phosphate solution is 20% of the total mass of the raw materials. Wet ball milling is carried out for 6 hours to form a uniform slurry. After the slurry is dried at 80 °C for 12 hours, it is screened through a 100-mesh sieve for standby.

[0173] On the basis of the matrix layer formula, the surface layer mixture is additionally added with 5% by mass of nano-Y 2 O 6 Si 2 O 7 powder. During the mixing process, a 20% magnesium dihydrogen phosphate solution is added, and the addition amount of the magnesium dihydrogen phosphate solution is 20% of the total mass of the raw materials. Wet ball milling is carried out for 6 hours to form a uniform slurry. After the slurry is dried at 80 °C for 12 hours, it is screened through a 100-mesh sieve for standby.

[0174] 3. Molding

[0175] The molding process uses the techniques of layered filling and cold isostatic pressing. First, the matrix layer mixture is filled into the mold, with a thickness of 90% of the total thickness, and then the surface layer mixture is filled, with a thickness of 10% of the total thickness. After filling, cold isostatic pressing is carried out at a pressure of 300 MPa and a holding time of 3 minutes to ensure the density and uniformity of the green body.

[0176] 4. Sintering

[0177] The sintering process includes three steps: pre-sintering, gas-pressure sintering, and hot isostatic pressing. First, the formed green body is pre-sintered at 800 °C for 2 hours with a heating rate of 3 °C / min to remove the binder. Subsequently, it is gas-pressure sintered at 1650 °C for 2 hours with nitrogen at 10 MPa introduced, and the heating rate is 5 °C / min. Finally, the sintered green body is subjected to hot isostatic pressing in an argon atmosphere at 1500 °C and 150 MPa for 1 hour, and the cooling rate is controlled at ≤5 °C / min to further eliminate internal defects and improve the material density. High-purity inert gas (nitrogen or argon) with an oxygen content of ≤10 ppm is used as the atmosphere for pre-sintering and gas-pressure sintering.

[0178] 5. Post-treatment

[0179] The post-treatment is a plasma spraying step. A 50-μm Al 2 O 3 -YAG composite coating is deposited on the surface by plasma spraying technology, and the spraying parameters are: current 500 A, gas flow rate Ar / H 2 = 45 / 15 SLPM, spraying distance 80 mm, spraying speed 200 mm / s. A densified anti-permeation zirconia refractory is prepared.

[0180] Table 2 Performance test results

[0181]

[0182] It can be seen from the tests of the examples (Table 2) that the zirconia refractory prepared by the present invention exhibits excellent performance in terms of bulk density (≥5.76 g / cm 3 ), apparent porosity (≤0.36%), flexural strength (≥535 MPa), and resistance to glass melt penetration (erosion depth ≤0.2 mm). Among them, Example 3 has outstanding performance, with a bulk density of 5.95 g / cm 3 , an apparent porosity of 0.28%, a flexural strength of 580 Mpa, and an erosion depth of 0.12 mm for resistance to glass melt penetration. Combining with the test results of the comparative examples, it can be known that the excellent comprehensive performance is due to the combined action of the gradient structure, grain boundary regulation, and surface defect repair.

[0183] Specifically, in the surface layer of the zirconia refractory prepared by the present invention, Y 2 O 6 Si 2 O 7 forms a continuous Y-Si-O transition layer with the matrix ZrO 2 , resulting in a gradient decrease in the Y element content from the surface to the matrix. This gradient structure enables the coefficient of thermal expansion to smoothly transition from approximately 5.8×10 -6 / °C in the surface layer to 10.5×10 -6 / °C, the interfacial stress is significantly reduced. This gradient structure effectively inhibits the phase transformation of ZrO 2 phase into the monoclinic phase, endowing the material with excellent flexural strength and anti-permeation performance. In the material, Y 3 + / Ce 4 + exists in the form of solid solution at the ZrO 2 grain boundaries, forming a (Y,Ce)-O-Si-Al composite glass phase. This high-viscosity glass phase can effectively block the diffusion paths of erosion ions such as Ca 2 + / Na+, so that the material shows the minimum erosion depth in the glass melt erosion test. The erosion depth of Example 3 is 0.12 mm, which is 71.4% lower than that of Comparative Example 2 (0.42 mm) without rare earth addition. At the same time, rare earth doping also further increases the grain boundary binding energy, which helps to improve the flexural strength. During the post-treatment process of the material, after molten salt impregnation, the surface open porosity is significantly reduced, and the B 2 O 3 -SiO 2 glass phase fills the defects with a size > 1 μm through capillary action.

[0184] The above embodiments are exemplary, and their purpose is to illustrate the technical concept and characteristics of the present invention, so that those skilled in this field can understand the content of the present invention and implement it accordingly, and it should not be used to limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for manufacturing a densified impermeable zirconia refractory component, characterized in that: The basic powder raw materials including the following components and amounts are selected: Zirconium dioxide 1000-1200 parts by mass; 200-300 parts by mass of single crystal aluminum oxide; 100-200 parts by mass of fused silica powder; 40-100 parts by mass of a boron compound; 40-60 parts by mass of rare earth oxide; 20-40 parts by mass of silicon carbide whiskers; 60-100 parts by mass of nano-alumina; 20-40 parts by mass of nano zirconium oxide; Phosphate binder 100-200 parts by mass; Pretreatment of raw materials: Grinding zirconium dioxide, single crystal alumina, fused quartz powder, boron compound and rare earth oxide to preset particle sizes respectively; calcining silicon carbide whiskers to remove surface impurities and then performing surface modification treatment with a silane coupling agent to improve dispersibility; Mix the ingredients: The matrix layer mixture is prepared by mixing zirconium dioxide, single crystal alumina, fused quartz powder, boron compound, rare earth oxide, silicon carbide whisker, nano alumina and nano zirconium oxide according to a formula; The surface layer mixture is based on the base layer formula, with 3-8% by mass of nano Y2O6Si2O7 powder added; Filling and molding of raw materials: Fill the mold with the base layer mixture, the thickness of which is 90-95% of the total thickness, and then fill the surface layer mixture, the thickness of which is 5-10% of the total thickness; after filling, cold isostatic pressing is performed; Sintering the formed green body: The formed green body is pre-sintered to remove the binder, and then gas pressure sintered under a protective atmosphere, and then the sintered green body is hot isostatically pressed to further eliminate internal defects and improve material density; Post-processing of sintered parts: The sintered part is treated with molten salt impregnation and plasma spraying to obtain a densified and impermeable zirconia refractory part.

2. The method for manufacturing a densified impermeable zirconia refractory component according to claim 1, characterized in that: In the process of pretreatment of raw materials, zirconium dioxide, single crystal alumina, fused quartz powder, boron compound and rare earth oxide are respectively ground to a particle size D50≤0.8μm, and 0.2% of the mass of the powder is added as a dispersant during the grinding process; in the process of surface modification of silicon carbide whiskers with a silane coupling agent, the concentration of the silane coupling agent used is 2-5%, and the amount used is 5-8% of the mass of the silicon carbide whiskers.

3. The method for manufacturing a densified impermeable zirconia refractory component according to claim 1, characterized in that: When preparing the surface layer mixture, the surface layer mixture is additionally added with 5% by mass of nano Y2O6Si2O7 powder on the basis of the base layer formula.

4. The method for manufacturing a densified impermeable zirconia refractory component according to claim 3, characterized in that: When preparing the base layer mixture, a 15-20% magnesium dihydrogen phosphate solution is added during the mixing process, and the amount of magnesium dihydrogen phosphate solution added is 10-20% of the total mass of the raw materials; when preparing the surface layer mixture, a 15-20% magnesium dihydrogen phosphate solution is added during the mixing process, and the amount of magnesium dihydrogen phosphate solution added is 10-20% of the total mass of the raw materials.

5. The method for manufacturing a densified impermeable zirconia refractory component according to claim 1, characterized in that: During the raw material filling and molding process, the cold isostatic pressing pressure is 250-350MPa and the holding time is 2-5 minutes.

6. The method for manufacturing a densified impermeable zirconia refractory component according to claim 1, characterized in that: During the sintering process of the formed green body, the formed green body is pre-sintered at 780-820°C for 1-5 hours with a heating rate of 2-4°C / min to remove the binder; then, it is gas-pressed sintered at 1600-1700°C for 1-3 hours, 8-12MPa nitrogen is introduced, and the heating rate is 4-6°C / min; the sintered green body is then hot isostatically pressed at 1400-1600°C and 120-180MPa argon environment for 0.8-1.5 hours, and the cooling rate is controlled at ≤5°C / min to further eliminate internal defects and improve the material density.

7. The method for manufacturing a densified impermeability-proof zirconia refractory component according to claim 6, characterized in that: The oxygen content in the atmosphere used for pre-sintering and gas pressure sintering is ≤10ppm.

8. The method for manufacturing a densified impermeability-proof zirconia refractory component according to claim 1, characterized in that: During the post-processing of the sintered parts, the sintered parts are immersed in molten borosilicate glass at 1200-1250°C for 25-40 minutes to fill the surface pores; after the immersion is completed, they are naturally cooled and the residual glass phase on the surface is removed.

9. The method for manufacturing a densified impermeability-proof zirconia refractory component according to claim 8, characterized in that: During the post-processing of the sintered parts, after molten salt impregnation, a 30-50 μm Al2O3-YAG composite coating is deposited on the surface by plasma spraying.

10. A densified impermeable zirconia refractory component, characterized in that: The refractory component is manufactured according to the manufacturing method according to any one of claims 1-9.

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