Corrosion-resistant quartz crucible and process for producing the same

Abstract

This invention provides a corrosion-resistant quartz crucible and its preparation process, belonging to the field of quartz crucible preparation technology. The preparation process includes the following steps: preparation of a quartz crucible blank; pretreatment of the quartz crucible blank; and preparation of the corrosion-resistant quartz crucible. This invention prepares the quartz crucible blank by injection molding modified fused silica powder and silicon powder. When the temperature rises above the melting point of Si, Si₂N₂O is generated. The in-situ generated Si₂N₂O grains inhibit the crystallization of fused silica at high temperatures, reducing the crystallization rate of the quartz crucible. Subsequently, a double coating is applied, effectively improving the corrosion resistance of the quartz crucible.

Description

Technical Field

[0001] This invention relates to the field of quartz crucible preparation technology, specifically to a corrosion-resistant quartz crucible and its preparation process. Background Technology

[0002] In modern industrial production, especially in high-end manufacturing fields such as semiconductors and photovoltaics, quartz crucibles play a crucial role. Due to their high purity, excellent high-temperature resistance, and stable physicochemical properties, quartz crucibles are key containers for holding high-temperature molten materials, such as molten silicon. In the semiconductor silicon wafer manufacturing process, high-purity polycrystalline silicon raw materials are melted in a quartz crucible and then pulled to grow crystals, producing single-crystal silicon rods that meet the requirements of semiconductor chip manufacturing. Similarly, the photovoltaic industry relies on quartz crucibles to melt silicon materials to produce single-crystal silicon ingots for solar cell manufacturing.

[0003] However, quartz crucibles face severe corrosion challenges in high-temperature melting environments. Taking silicon melt as an example, at high temperatures, silicon undergoes complex chemical reactions with the silicon dioxide in the quartz crucible, leading to gradual erosion of the crucible's inner wall. This not only reduces the service life of the quartz crucible and increases production costs due to frequent crucible replacements, but also may cause impurities generated by corrosion to enter the melt, severely affecting the purity and quality of monocrystalline silicon.

[0004] To address the challenging problem of corrosion resistance, the industry has undertaken numerous attempts. Some companies have tried to enhance the corrosion resistance of crucibles by improving the purity of quartz raw materials; however, due to the scarcity of high-quality quartz ore resources and the complexity and high cost of purification processes, the actual improvement effect is difficult to achieve as expected. Other companies have adopted the method of coating the crucible surface with protective coatings, but existing coating materials have poor bonding stability with the quartz matrix under high temperature and strong corrosive environments, easily leading to coating peeling and a significant reduction in protective performance. This fails to effectively solve the severe corrosion problem faced by quartz crucibles in actual use.

[0005] Furthermore, quartz crucibles are prone to crystallization at high temperatures. Severe crystallization can affect the quality of the finished monocrystalline silicon product. At the same time, crystallization on the inner wall of the quartz crucible may also damage the coating on the inner wall, resulting in a significant reduction in its protective performance and thus reducing its corrosion resistance.

[0006] Therefore, it is necessary to develop a preparation process that reduces crystallization and improves the corrosion resistance of quartz crucibles in order to solve the defects of quartz crucibles. Summary of the Invention

[0007] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a corrosion-resistant quartz crucible and its preparation process.

[0008] In a first aspect, this application provides a process for preparing a corrosion-resistant quartz crucible, comprising the following steps:

[0009] S1: Preparation of quartz crucible blank

[0010] Fused quartz powder was modified with KH-550 silane coupling agent, then ball-milled with silicon powder, lactic acid, polyvinyl alcohol, gel mixture and deionized water, then solidified with ammonium persulfate, and finally sintered under nitrogen atmosphere to prepare quartz crucible blanks.

[0011] S2: Pretreatment of quartz crucible blank

[0012] The quartz crucible blank was subjected to plasma etching, and then coated with a composite slurry prepared by mixing quartz powder with a purity of 99.9%, nano-cerium oxide and silica sol. After drying, it was sintered to obtain the pretreated quartz crucible blank.

[0013] S3: Preparation of corrosion-resistant quartz crucibles

[0014] ZrB2-SiC composite particles were prepared, and then ZrB2-SiC composite particles, silica sol, Y2O3 and deionized water were mixed to prepare a mixture. The mixture was sprayed onto the inner surface of the pretreated quartz crucible blank, and then dried and sintered to prepare a corrosion-resistant quartz crucible.

[0015] Furthermore, the preparation of the quartz crucible blank in step S1 specifically includes the following steps:

[0016] S1.1: Add 100-120 parts by weight of fused silica powder to 120-180 parts by weight of deionized water, then adjust the pH to 5-6, then add 2-3 parts by weight of KH-550 silane coupling agent, stir and mix evenly to obtain a mixture, place the mixture at 70-80℃ and stir for 5-8 hours, then dry and grind to obtain modified fused silica powder;

[0017] S1.2: Mix 49-63 parts by weight of N,N-dimethylacrylamide and 1-2 parts by weight of NN'-methylenebisacrylamide to obtain a gel mixture;

[0018] S1.3: Place 69-76 parts by weight of modified fused silica powder, 5-8 parts by weight of silica powder, 0.4-0.5 parts by weight of lactic acid, 0.5-1 parts by weight of polyvinyl alcohol, 13-21 parts by weight of gel mixture and 29-43 parts by weight of deionized water in a polypropylene ball mill jar. Add ball milling media at a mass ratio of powder to zirconia balls of 1:2-3. Then place the ball mill jar in a planetary ball mill and ball mill at 600-700 r / min for 2-3 h to obtain a mixed slurry.

[0019] S1.4: Mix the slurry with 0.6-1.5 parts by weight of ammonium persulfate and pour it into the mold. Heat to 50-60℃ and hold for 15-18 minutes to gel and solidify. Demold to obtain a quartz crucible preform. Sinter the quartz crucible preform under a nitrogen atmosphere and finally cool it in the furnace to obtain the quartz crucible blank.

[0020] Furthermore, the pretreatment of the quartz crucible blank in step S2 specifically includes the following steps:

[0021] S2.1: The inner surface of the quartz crucible blank is plasma etched at 500-600W for 20-30 minutes using a mixed gas of Ar and O2 at a volume ratio of 4:1 to obtain a quartz crucible blank with nanogrooves on the inner surface.

[0022] S2.2: Mix 20-30 parts by weight of quartz powder with a purity of 99.9% with nano-cerium oxide, place the mixture in a zirconia ball mill jar, with a liquid-solid mass ratio of 2-3:1, and ball mill with anhydrous ethanol at 300-400 r / min for 20-24 h to obtain a slurry. Mix 2-3 parts by weight of the slurry with 1-2 parts by weight of silica sol for 30-50 min to obtain a composite slurry.

[0023] S2.3: The composite slurry is coated on the inner surface of the quartz crucible blank containing nanogrooves, with a coating thickness of 0.1-0.3 mm. The coated quartz crucible blank is then naturally dried at 25°C for 1-2 h, and then dried at 130-150°C for 2-3 h. After drying, it is vacuum sintered at 800-820°C for 1-2 h to obtain the pretreated quartz crucible blank.

[0024] Furthermore, the preparation of the corrosion-resistant quartz crucible in step S3 specifically includes the following steps:

[0025] S3.1: Mix ZrB2 powder with a purity of 99.5% and a particle size of 0.8μm with SiC powder with a purity of 99.9% and a particle size of 1.2μm at a molar ratio of 6:3-4, then add 0.5wt% phenolic resin, stir and mix to obtain a mixture, and spray granulate the mixture to obtain ZrB2-SiC composite particles.

[0026] S3.2: Place 50-60 parts by weight of ZrB2-SiC composite particles, 5-8 parts by weight of silica sol, 2-3 parts by weight of Y2O3, and 5-10 parts by weight of deionized water in a zirconia ball mill jar and ball mill at 300-400 r / min for 20-24 h to obtain a mixture. Spray the mixture onto the inner surface of the pretreated quartz crucible blank and allow it to dry naturally at 25℃ for 1-2 h. Then place it in a vacuum-sealed furnace, introduce 99.99% pure Ar into the furnace, and sinter at 1500-1700℃ for 4-8 h at 100-120 Pa and with an oxygen content of less than 0.01% in the furnace to obtain a corrosion-resistant quartz crucible.

[0027] Further, the sintering process in step S1.4 is as follows: the temperature is increased to 200-300℃ at a heating rate of 2-3℃ / min and held for 1-2 hours, then increased to 400-500℃ at a heating rate of 5℃ / min and held for 1-2 hours, then increased to 800-900℃ at a heating rate of 10℃ / min and held for 1-2 hours, and then increased to 1550-1600℃ at a heating rate of 10℃ / min and held for 1-2 hours.

[0028] Furthermore, in step S2.2, nano-cerium oxide is added at a Ce / Si molar ratio of 1:20-22.

[0029] Furthermore, in step S3.1, the spray granulation parameters are: inlet temperature 180-200℃, outlet temperature 80-90℃, and atomization pressure 0.3-0.5MPa.

[0030] Secondly, this application provides a corrosion-resistant quartz crucible, which is prepared by the preparation process of a corrosion-resistant quartz crucible as described in any one of the claims.

[0031] Compared with the prior art, the present invention has at least the following beneficial effects:

[0032] 1. In this invention, modified fused silica powder and silicon powder are injection molded to prepare a quartz crucible blank. The silane coupling agent is hydrolyzed to generate silanol groups, which can undergo a condensation reaction with the hydroxyl groups on the surface of the fused silica powder to form stable chemical bonds. At the same time, the organic groups at the other end can better combine with other organic components, thereby enhancing the compatibility and bonding force between the fused silica powder and subsequent organic materials. Then, sintering is carried out under a nitrogen atmosphere. When the temperature rises above the melting point of Si, Si2N2O will be generated. The in-situ generated Si2N2O grains inhibit the crystallization of fused silica at high temperature and reduce the crystallization rate of the quartz crucible.

[0033] 2. This invention introduces polyvinyl alcohol (PVA) during the preparation of the quartz crucible blank. During the sintering process, PVA undergoes intermolecular dehydration at 200°C; once the temperature exceeds 200°C, intramolecular dehydration begins, forming a polymer with conjugated double bonds. Only when the temperature rises above 800°C is PVA completely eliminated. During this period, PVA exhibits viscous flow within the product, which significantly strengthens the quartz network structure, inhibiting oxygen diffusion. Because it is difficult to achieve the Si / O stoichiometric ratio required for the precipitation of cristobalite crystals, the amount of crystallization is significantly reduced.

[0034] 3. This invention uses a mixture of Ar and O2 gas to perform plasma etching on the inner surface of the quartz crucible blank, forming nanogrooves, increasing surface roughness, providing physical anchors for subsequent coating adhesion, and enhancing the adhesion between the coating and the substrate. At the same time, the surface chemical activity is improved after etching, which is beneficial to subsequent chemical reactions and coating adhesion. In the composite slurry of high-purity quartz powder and nano-cerium oxide, Ce is uniformly embedded in the SiO2 network through ball milling to form an amorphous structure, which hinders the rearrangement of SiO2 lattice. Furthermore, CeO2 acts as a grain boundary pinning agent to inhibit the β-cristobalite phase transformation. After the silica sol is combined with the slurry, a dense amorphous layer is formed at high temperature, sealing the pores. Nano-CeO2 fills the quartz grain boundaries, thereby reducing the penetration path of molten silicon and effectively improving the corrosion resistance of the quartz crucible.

[0035] 4. Finally, this invention employs a composite coating of ZrB2-SiC composite particles and Y2O3. ZrB2 possesses a high melting point, high hardness, and good chemical stability, while SiC exhibits excellent chemical corrosion resistance. The coating formed by these two composites effectively resists the erosion of the quartz crucible by the silicon melt at high temperatures, extending the crucible's service life. During the preparation of the silicon melt, the melt is at a high temperature and possesses certain chemical activity, readily reacting with the crucible material. The ZrB2-SiC composite coating forms a robust barrier, preventing direct contact between the silicon melt and the quartz crucible substrate, thereby reducing erosion. Both ZrB2 and SiC have high melting points and good high-temperature mechanical properties, allowing the composite coating to maintain a stable structure and performance at high temperatures, making it less prone to deformation or damage. Furthermore, the addition of Y2O3 further enhances the coating's high-temperature stability and oxidation resistance. During the nitriding sintering process, Y2O3 interacts with other components to form a denser and more stable microstructure, which enhances the coating's resistance to thermal shock and oxidation at high temperatures, ensuring that the quartz crucible can be used for a long time in high-temperature environments. Attached Figure Description

[0036] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate embodiments of the invention and, together with the specification, further serve to explain the principles of the invention and enable those skilled in the art to practice and use the invention.

[0037] Figure 1 This is a process flow diagram of the preparation process of a corrosion-resistant quartz crucible used in an embodiment of the present invention. Detailed Implementation

[0038] The preparation process of a corrosion-resistant quartz crucible provided by the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, to make the embodiments more detailed, the following embodiments are the best and preferred embodiments, and those skilled in the art can use other alternative methods to implement some known technologies; moreover, the accompanying drawings are only for more specific description of the embodiments and are not intended to specifically limit the present invention.

[0039] Example 1

[0040] A process for preparing a corrosion-resistant quartz crucible, such as... Figure 1 As shown, it includes the following steps:

[0041] S1: Preparation of quartz crucible blank

[0042] S1.1: Add 100 parts by weight of fused silica powder to 120 parts by weight of deionized water, then adjust the pH to 5, then add 2 parts by weight of KH-550 silane coupling agent, stir and mix evenly to obtain a mixture, place the mixture at 70℃ and stir for 5 hours, then dry and grind to obtain modified fused silica powder.

[0043] S1.2: Mix 49 parts by weight of N,N-dimethylacrylamide and 1 part by weight of NN'-methylenebisacrylamide to obtain a gel mixture;

[0044] S1.3: 69 parts by weight of modified fused silica powder, 5 parts by weight of silica powder, 0.4 parts by weight of lactic acid, 0.5 parts by weight of polyvinyl alcohol, 13 parts by weight of gel mixture and 29 parts by weight of deionized water were placed in a polypropylene ball mill jar. The ball milling media were added at a mass ratio of powder to zirconia balls of 1:2. Then the ball mill jar was placed in a planetary ball mill and ball milled at 600 r / min for 2 h to obtain a mixed slurry.

[0045] S1.4: Mix the slurry with 0.6 parts by weight of ammonium persulfate and pour it into the mold. Heat to 50°C and hold for 15 min to gel solidify. Demold to obtain a quartz crucible preform. Sinter the quartz crucible preform under a nitrogen atmosphere. The sintering process is as follows: heat to 200°C at a heating rate of 2°C / min and hold for 1 h, then heat to 400°C at a heating rate of 5°C / min and hold for 1 h, then heat to 800°C at a heating rate of 10°C / min and hold for 1 h, then heat to 1550°C at a heating rate of 10°C / min and hold for 1 h, and finally cool with the furnace to obtain the quartz crucible preform.

[0046] S2: Pretreatment of quartz crucible blank

[0047] S2.1: The inner surface of the quartz crucible blank was plasma etched at 500W for 20 minutes using a mixed gas of Ar and O2 at a volume ratio of 4:1 to obtain a quartz crucible blank with nanogrooves on the inner surface.

[0048] S2.2: Mix 20 parts by weight of quartz powder with a purity of 99.9% with nano-cerium oxide, add nano-cerium oxide at a Ce / Si molar ratio of 1:20, place the mixture in a zirconia ball mill jar, with a liquid-solid mass ratio of 3:1, and ball mill at 300 r / min for 20 h with anhydrous ethanol to obtain a slurry. Mix 2 parts by weight of the slurry with 1 part by weight of silica sol for 30 min to obtain a composite slurry.

[0049] S2.3: The composite slurry is coated on the inner surface of the quartz crucible blank containing nanogrooves, with a coating thickness of 0.1 mm. The coated quartz crucible blank is then naturally dried at 25°C for 1 h, then dried at 130°C for 2 h, and finally vacuum sintered at 800°C for 1 h to obtain the pretreated quartz crucible blank.

[0050] S3: Preparation of corrosion-resistant quartz crucibles

[0051] S3.1: ZrB2 powder with a purity of 99.5% and a particle size of 0.8μm and SiC powder with a purity of 99.9% and a particle size of 1.2μm are mixed at a molar ratio of 6:3. Then, 0.5wt% phenolic resin is added and stirred to obtain a mixture. The mixture is spray granulated at an inlet temperature of 180℃, an outlet temperature of 80℃, and an atomization pressure of 0.3MPa to obtain ZrB2-SiC composite particles.

[0052] S3.2: 50 parts by weight of ZrB2-SiC composite particles, 5 parts by weight of silica sol, 2 parts by weight of Y2O3, and 5 parts by weight of deionized water were placed in a zirconia ball mill jar and ball-milled at 300 r / min for 20 h to obtain a mixture. The mixture was sprayed onto the inner surface of the pretreated quartz crucible blank and dried naturally at 25 °C for 1 h. Then it was placed in a vacuum-sealed furnace, and Ar with a purity of 99.99% was introduced into the furnace. After that, it was sintered at 1500 °C for 4 h at 100 Pa and with an oxygen content of less than 0.01% in the furnace to obtain a corrosion-resistant quartz crucible.

[0053] Example 2

[0054] A process for preparing a corrosion-resistant quartz crucible, such as... Figure 1 As shown, it includes the following steps:

[0055] S1: Preparation of quartz crucible blank

[0056] S1.1: Add 120 parts by weight of fused silica powder to 180 parts by weight of deionized water, then adjust the pH to 6, then add 3 parts by weight of KH-550 silane coupling agent, stir and mix evenly to obtain a mixture, place the mixture at 70℃ and stir for 5 hours, then dry and grind to obtain modified fused silica powder.

[0057] S1.2: Mix 63 parts by weight of N,N-dimethylacrylamide and 2 parts by weight of NN'-methylenebisacrylamide to obtain a gel mixture;

[0058] S1.3: 76 parts by weight of modified fused silica powder, 8 parts by weight of silica powder, 0.5 parts by weight of lactic acid, 1 part by weight of polyvinyl alcohol, 21 parts by weight of gel mixture and 43 parts by weight of deionized water were placed in a polypropylene ball mill jar. The ball milling media were added at a mass ratio of powder to zirconia balls of 1:3. Then the ball mill jar was placed in a planetary ball mill and ball milled at 600 r / min for 2 h to obtain a mixed slurry.

[0059] S1.4: Mix the slurry with 1.5 parts by weight of ammonium persulfate and pour it into the mold. Heat to 50°C and hold for 15 min to gel solidify. Demold to obtain a quartz crucible preform. Sinter the quartz crucible preform under a nitrogen atmosphere. The sintering process is as follows: heat to 200°C at a heating rate of 2°C / min and hold for 1 h, then heat to 400°C at a heating rate of 5°C / min and hold for 1 h, then heat to 800°C at a heating rate of 10°C / min and hold for 1 h, then heat to 1550°C at a heating rate of 10°C / min and hold for 1 h, and finally cool with the furnace to obtain the quartz crucible preform.

[0060] S2: Pretreatment of quartz crucible blank

[0061] S2.1: The inner surface of the quartz crucible blank was plasma etched at 500W for 20 minutes using a mixed gas of Ar and O2 at a volume ratio of 4:1 to obtain a quartz crucible blank with nanogrooves on the inner surface.

[0062] S2.2: Mix 30 parts by weight of quartz powder with a purity of 99.9% with nano-cerium oxide, add nano-cerium oxide at a Ce / Si molar ratio of 1:22, place the mixture in a zirconia ball mill jar, with a liquid-solid mass ratio of 2:1, and ball mill at 300 r / min for 20 h with anhydrous ethanol to obtain a slurry. Mix 3 parts by weight of the slurry with 2 parts by weight of silica sol for 30 min to obtain a composite slurry.

[0063] S2.3: The composite slurry is coated on the inner surface of the quartz crucible blank containing nanogrooves, with a coating thickness of 0.3 mm. The coated quartz crucible blank is then naturally dried at 25°C for 1 h, then dried at 130°C for 2 h, and finally vacuum sintered at 800°C for 1 h to obtain the pretreated quartz crucible blank.

[0064] S3: Preparation of corrosion-resistant quartz crucibles

[0065] S3.1: ZrB2 powder with a purity of 99.5% and a particle size of 0.8μm and SiC powder with a purity of 99.9% and a particle size of 1.2μm are mixed at a molar ratio of 6:4. Then, 0.5wt% phenolic resin is added and stirred to obtain a mixture. The mixture is spray granulated at an inlet temperature of 180℃, an outlet temperature of 80℃, and an atomization pressure of 0.3MPa to obtain ZrB2-SiC composite particles.

[0066] S3.2: 60 parts by weight of ZrB2-SiC composite particles, 8 parts by weight of silica sol, 3 parts by weight of Y2O3, and 10 parts by weight of deionized water were placed in a zirconia ball mill jar and ball-milled at 300 r / min for 20 h to obtain a mixture. The mixture was sprayed onto the inner surface of the pretreated quartz crucible blank and dried naturally at 25 °C for 1 h. Then it was placed in a vacuum-sealed furnace, and Ar with a purity of 99.99% was introduced into the furnace. After that, it was sintered at 1500 °C for 4 h at 100 Pa and with an oxygen content of less than 0.01% in the furnace to obtain a corrosion-resistant quartz crucible.

[0067] Example 3

[0068] A process for preparing a corrosion-resistant quartz crucible, such as... Figure 1 As shown, it includes the following steps:

[0069] S1: Preparation of quartz crucible blank

[0070] S1.1: Add 110 parts by weight of fused silica powder to 150 parts by weight of deionized water, then adjust the pH to 5, then add 2.5 parts by weight of KH-550 silane coupling agent, stir and mix evenly to obtain a mixture, place the mixture at 80℃ and stir for 8 hours, then dry and grind to obtain modified fused silica powder.

[0071] S1.2: Mix 55 parts by weight of N,N-dimethylacrylamide and 1.5 parts by weight of NN'-methylenebisacrylamide to obtain a gel mixture;

[0072] S1.3: 72 parts by weight of modified fused silica powder, 6.5 parts by weight of silica powder, 0.45 parts by weight of lactic acid, 0.7 parts by weight of polyvinyl alcohol, 18 parts by weight of gel mixture and 45 parts by weight of deionized water were placed in a polypropylene ball mill jar. The ball milling media were added at a mass ratio of powder to zirconia balls of 1:2.5. Then the ball mill jar was placed in a planetary ball mill and ball milled at 700 r / min for 3 h to obtain a mixed slurry.

[0073] S1.4: Mix the slurry with 1 part by weight of ammonium persulfate and pour it into the mold. Heat to 60°C and hold for 18 min to gel solidify. Demold to obtain a quartz crucible preform. Sinter the quartz crucible preform under a nitrogen atmosphere. The sintering process is as follows: heat to 300°C at a heating rate of 3°C / min and hold for 2 h, then heat to 500°C at a heating rate of 5°C / min and hold for 2 h, then heat to 900°C at a heating rate of 10°C / min and hold for 2 h, then heat to 1600°C at a heating rate of 10°C / min and hold for 2 h, and finally cool with the furnace to obtain the quartz crucible preform.

[0074] S2: Pretreatment of quartz crucible blank

[0075] S2.1: The inner surface of the quartz crucible blank was plasma etched at 600W for 30 minutes using a mixed gas of Ar and O2 at a volume ratio of 4:1 to obtain a quartz crucible blank with nanogrooves on the inner surface.

[0076] S2.2: Mix 25 parts by weight of quartz powder with a purity of 99.9% with nano-cerium oxide, add nano-cerium oxide at a Ce / Si molar ratio of 1:20, place the mixture in a zirconia ball mill jar, with a liquid-solid mass ratio of 2.5:1, and ball mill at 400 r / min for 24 h with anhydrous ethanol to obtain a slurry. Mix 2.5 parts by weight of the slurry with 1.5 parts by weight of silica sol for 50 min to obtain a composite slurry.

[0077] S2.3: The composite slurry is coated on the inner surface of the quartz crucible blank containing nanogrooves, with a coating thickness of 0.1 mm. The coated quartz crucible blank is then naturally dried at 25°C for 2 h, then dried at 150°C for 3 h, and finally vacuum sintered at 820°C for 2 h to obtain the pretreated quartz crucible blank.

[0078] S3: Preparation of corrosion-resistant quartz crucibles

[0079] S3.1: ZrB2 powder with a purity of 99.5% and a particle size of 0.8μm and SiC powder with a purity of 99.9% and a particle size of 1.2μm are mixed at a molar ratio of 6:3.5. Then, 0.5wt% phenolic resin is added and stirred to obtain a mixture. The mixture is spray granulated at an inlet temperature of 200℃, an outlet temperature of 90℃, and an atomization pressure of 0.5MPa to obtain ZrB2-SiC composite particles.

[0080] S3.2: 55 parts by weight of ZrB2-SiC composite particles, 6.5 parts by weight of silica sol, 2.5 parts by weight of Y2O3, and 7.5 parts by weight of deionized water were placed in a zirconia ball mill jar and ball-milled at 400 r / min for 24 h to obtain a mixture. The mixture was sprayed onto the inner surface of the pretreated quartz crucible blank and dried naturally at 25 °C for 2 h. Then it was placed in a vacuum-sealed furnace, and Ar with a purity of 99.99% was introduced into the furnace. After that, it was sintered at 1700 °C for 8 h at 120 Pa and with an oxygen content of less than 0.01% in the furnace to obtain a corrosion-resistant quartz crucible.

[0081] Comparative Example 1

[0082] Compared with Example 1, the difference of Comparative Example 1 is that the silicon powder in step S1.3 is removed, and the sintering of the quartz crucible green in step S1.4 under a nitrogen atmosphere is changed to sintering the quartz crucible green in an argon atmosphere. The other steps remain unchanged to prepare a corrosion-resistant quartz crucible, and it is referred to as Comparative Example 1.

[0083] Comparative Example 2

[0084] Compared with Example 1, Comparative Example 2 differs in that the polyvinyl alcohol in step S1.3 is removed in Comparative Example 2, while the remaining steps remain unchanged to prepare a corrosion-resistant quartz crucible, and is referred to as Comparative Example 2.

[0085] Comparative Example 3

[0086] Compared with Example 1, Comparative Example 3 differs in that step S2.1 is removed, and the quartz crucible blank containing nanogrooves in step S2.3 is replaced with a quartz crucible blank, while the remaining steps remain unchanged to prepare a corrosion-resistant quartz crucible. This is referred to as Comparative Example 3.

[0087] Comparative Example 4

[0088] Compared with Example 1, the difference of Comparative Example 4 is that steps S2.2-S2.3 are removed in Comparative Example 4, and the pretreated quartz crucible blank in step S3.2 is replaced with a quartz crucible blank with nanogrooves on the inner surface. The remaining steps are unchanged to prepare a corrosion-resistant quartz crucible, and it is referred to as Comparative Example 4.

[0089] Comparative Example 5

[0090] Compared with Example 1, Comparative Example 5 differs in that step S3 is removed in Comparative Example 5, and a silicon nitride coating is sprayed on the surface of the pretreated quartz crucible blank. The remaining steps are unchanged to prepare a corrosion-resistant quartz crucible, and it is referred to as Comparative Example 5.

[0091] Five quartz crucible samples, each measuring 100 mm × 100 mm, were cut from the straight walls of the corrosion-resistant quartz crucibles prepared in Examples 1-3 and Comparative Examples 1-2. The cut edges of the quartz crucible samples were smoothed with silicon carbide, and then the samples were immersed in 10% analytical grade hydrochloric acid for 20 minutes. After immersion, the samples were rinsed three times with deionized water, and then three times with anhydrous ethanol, followed by wiping clean. The samples were then placed at 1500°C for 8 hours. After cooling to 25°C, the samples were visually inspected, and the results are shown in Table 1.

[0092] Table 1. Results of Anti-crystallization Test

[0093]

[0094] As can be seen from the data in Table 1, the corrosion-resistant quartz crucible prepared by the present invention, which uses modified fused silica powder and silicon powder to form a solidification molding process, then introduces polyvinyl alcohol, and sintersulates under a nitrogen atmosphere, can reduce the crystallization phenomenon of the quartz crucible.

[0095] High-temperature molten silicon was placed into the quartz crucibles prepared in Examples 1-3 and Comparative Examples 3-5, and then heated to 1600°C. After holding at this temperature for a certain period of time, the crucibles were cooled. This high-temperature melting operation was repeated six times. Afterward, the inner wall of the quartz crucibles was observed to see if erosion, peeling, or cracks appeared. The measurement results are shown in Table 2.

[0096] Table 2. Results of corrosion resistance tests for Examples 1-3 and Comparative Examples 3-5

[0097]

[0098] The data from Comparative Example 3 in Table 2 show that plasma etching of the inner surface of the quartz crucible blank using a mixture of Ar and O2 gas can enhance the adhesion between the coating and the substrate and reduce coating peeling. The data from Comparative Examples 4 and 5 show that the coating prepared by the composite slurry of high-purity quartz powder and nano-cerium oxide effectively improves the corrosion resistance of the quartz crucible. The composite coating using ZrB2-SiC composite particles and Y2O3 can prevent direct contact between the silicon melt and the quartz crucible substrate, thereby reducing erosion.

[0099] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A process for preparing a corrosion-resistant quartz crucible, characterized in that, Includes the following steps: S1: Preparation of quartz crucible blank Fused quartz powder was modified with KH-550 silane coupling agent, then ball-milled with silicon powder, lactic acid, polyvinyl alcohol, gel mixture and deionized water, then solidified with ammonium persulfate, and finally sintered under nitrogen atmosphere to prepare quartz crucible blanks. S2: Pretreatment of quartz crucible blank The quartz crucible blank was subjected to plasma etching, and then coated with a composite slurry prepared by mixing quartz powder with a purity of 99.9%, nano-cerium oxide and silica sol. After drying, it was sintered to obtain the pretreated quartz crucible blank. S3: Preparation of corrosion-resistant quartz crucibles ZrB2-SiC composite particles were prepared, and then ZrB2-SiC composite particles, silica sol, Y2O3 and deionized water were mixed to prepare a mixture. The mixture was sprayed onto the inner surface of the pretreated quartz crucible blank, and then dried and sintered to prepare a corrosion-resistant quartz crucible.

2. The preparation process of a corrosion-resistant quartz crucible according to claim 1, characterized in that, Step S1, the preparation of the quartz crucible blank, specifically includes the following steps: S1.1: Add 100-120 parts by weight of fused silica powder to 120-180 parts by weight of deionized water, then adjust the pH to 5-6, then add 2-3 parts by weight of KH-550 silane coupling agent, stir and mix evenly to obtain a mixture, place the mixture at 70-80℃ and stir for 5-8 hours, then dry and grind to obtain modified fused silica powder; S1.2: Mix 49-63 parts by weight of N,N-dimethylacrylamide and 1-2 parts by weight of NN'-methylenebisacrylamide to obtain a gel mixture; S1.3: Place 69-76 parts by weight of modified fused silica powder, 5-8 parts by weight of silica powder, 0.4-0.5 parts by weight of lactic acid, 0.5-1 parts by weight of polyvinyl alcohol, 13-21 parts by weight of gel mixture and 29-43 parts by weight of deionized water in a polypropylene ball mill jar. Add ball milling media at a mass ratio of powder to zirconia balls of 1:2-3. Then place the ball mill jar in a planetary ball mill and ball mill at 600-700 r / min for 2-3 h to obtain a mixed slurry. S1.4: Mix the slurry with 0.6-1.5 parts by weight of ammonium persulfate and pour it into the mold. Heat to 50-60℃ and hold for 15-18 minutes to gel and solidify. Demold to obtain a quartz crucible preform. Sinter the quartz crucible preform under a nitrogen atmosphere and finally cool it in the furnace to obtain the quartz crucible blank.

3. The preparation process of a corrosion-resistant quartz crucible according to claim 2, characterized in that, Step S2, the pretreatment of the quartz crucible blank, specifically includes the following steps: S2.1: The inner surface of the quartz crucible blank is plasma etched at 500-600W for 20-30 minutes using a mixed gas of Ar and O2 at a volume ratio of 4:1 to obtain a quartz crucible blank with nanogrooves on the inner surface. S2.2: Mix 20-30 parts by weight of quartz powder with a purity of 99.9% with nano-cerium oxide, place the mixture in a zirconia ball mill jar, with a liquid-solid mass ratio of 2-3:1, and ball mill with anhydrous ethanol at 300-400 r / min for 20-24 h to obtain a slurry. Mix 2-3 parts by weight of the slurry with 1-2 parts by weight of silica sol for 30-50 min to obtain a composite slurry. S2.3: The composite slurry is coated on the inner surface of the quartz crucible blank containing nanogrooves, with a coating thickness of 0.1-0.3 mm. The coated quartz crucible blank is then naturally dried at 25°C for 1-2 h, and then dried at 130-150°C for 2-3 h. After drying, it is vacuum sintered at 800-820°C for 1-2 h to obtain the pretreated quartz crucible blank.

4. The preparation process of a corrosion-resistant quartz crucible according to claim 3, characterized in that, Step S3, the preparation of the corrosion-resistant quartz crucible, specifically includes the following steps: S3.1: Mix ZrB2 powder with a purity of 99.5% and a particle size of 0.8μm with SiC powder with a purity of 99.9% and a particle size of 1.2μm at a molar ratio of 6:3-4, then add 0.5wt% phenolic resin, stir and mix to obtain a mixture, and spray granulate the mixture to obtain ZrB2-SiC composite particles. S3.2: Place 50-60 parts by weight of ZrB2-SiC composite particles, 5-8 parts by weight of silica sol, 2-3 parts by weight of Y2O3, and 5-10 parts by weight of deionized water in a zirconia ball mill jar and ball mill at 300-400 r / min for 20-24 h to obtain a mixture. Spray the mixture onto the inner surface of the pretreated quartz crucible blank and allow it to dry naturally at 25℃ for 1-2 h. Then place it in a vacuum-sealed furnace, introduce 99.99% pure Ar into the furnace, and sinter at 1500-1700℃ for 4-8 h at 100-120 Pa and with an oxygen content of less than 0.01% in the furnace to obtain a corrosion-resistant quartz crucible.

5. The preparation process of a corrosion-resistant quartz crucible according to claim 2, characterized in that, The sintering process in step S1.4 is as follows: the temperature is increased to 200-300℃ at a heating rate of 2-3℃ / min and held for 1-2 hours, then increased to 400-500℃ at a heating rate of 5℃ / min and held for 1-2 hours, then increased to 800-900℃ at a heating rate of 10℃ / min and held for 1-2 hours, and then increased to 1550-1600℃ at a heating rate of 10℃ / min and held for 1-2 hours.

6. The preparation process of a corrosion-resistant quartz crucible according to claim 3, characterized in that, In step S2.2, nano-cerium oxide is added at a Ce / Si molar ratio of 1:20-22.

7. The preparation process of a corrosion-resistant quartz crucible according to claim 4, characterized in that, In step S3.1, the spray granulation parameters are: inlet temperature 180-200℃, outlet temperature 80-90℃, and atomization pressure 0.3-0.5MPa.

8. A corrosion-resistant quartz crucible, characterized in that, It is prepared by the preparation process of a corrosion-resistant quartz crucible as described in any one of claims 1-7.

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