Corrosion-resistant quartz crucible and preparation process thereof

Abstract

The invention provides a corrosion-resistant quartz crucible and a preparation process thereof, and belongs to the technical field of quartz crucible preparation. The preparation process comprises the following steps: preparing a quartz crucible blank; pre-treating a quartz crucible blank body; and preparing the corrosion-resistant quartz crucible. The quartz crucible blank is prepared from the modified fused quartz powder and the silicon powder through gel casting, when the temperature rises to the melting point of Si or above, Si2N2O can be generated, in-situ generated Si2N2O grains inhibit crystallization of fused quartz at a high temperature, the crystallization rate of the quartz crucible is reduced, and then double coatings are adopted, so that the crystallization rate of the quartz crucible is increased, and the service life of the quartz crucible is prolonged. And the corrosion resistance of the quartz crucible is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of quartz crucible preparation, and particularly relates to a corrosion-resistant quartz crucible and its preparation process. Background Art

[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, good high-temperature resistance, and stable physical and chemical properties, quartz crucibles have become key containers for holding high-temperature melts, such as silicon melts. In the process of manufacturing semiconductor silicon wafers, high-purity polysilicon raw materials need to be melted in a quartz crucible and then pulled for crystal growth to produce single-crystal silicon rods that meet the requirements of semiconductor chip manufacturing; in the photovoltaic industry, quartz crucibles are also relied on to melt silicon materials and then produce single-crystal silicon ingots for solar cell manufacturing.

[0003] However, in a high-temperature melting environment, quartz crucibles face severe corrosion challenges. Taking silicon melt as an example, at high temperatures, silicon will react with silicon dioxide in the quartz crucible to cause complex chemical reactions, resulting in the gradual erosion of the inner wall of the crucible. This not only reduces the service life of the quartz crucible, increases production costs due to frequent crucible replacement, but also may cause impurities generated by corrosion to mix into the melt, seriously affecting the purity and quality of single-crystal silicon.

[0004] To address the intractable corrosion problem, many attempts have been made in the industry. Some enterprises have tried to enhance the corrosion resistance of the crucible by improving the purity of quartz raw materials. However, due to the scarcity of high-quality quartz ore resources, the purification process is complex and costly, and the actual improvement effect is difficult to meet expectations. There are also enterprises that use the method of coating a protective coating on the surface of the crucible. However, the existing coating materials have poor bonding stability with the quartz matrix in a high-temperature and strong-corrosion environment, and it is easy to have the phenomenon of coating peeling off, resulting in a significant reduction in the protective performance and being unable to effectively solve the severe corrosion problem faced by quartz crucibles in actual use.

[0005] Moreover, quartz crucibles are prone to devitrification at high temperatures. Severe devitrification will affect the quality of single-crystal silicon products. At the same time, when devitrification occurs on the inner wall of the quartz crucible, it may also damage the coating on the inner wall of the crucible, resulting in a significant reduction in its protective performance and thus reducing the corrosion resistance.

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

[0007] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a corrosion-resistant quartz crucible and its preparation process.

[0008] In a first aspect, the present application provides a preparation process for a corrosion-resistant quartz crucible, including the following steps: S1: Preparation of quartz crucible blank Modify the fused quartz powder with KH-550 silane coupling agent, then ball mill it with silicon powder, lactic acid, polyvinyl alcohol, gel mixture and deionized water, then add ammonium persulfate for curing, and finally sinter it under nitrogen atmosphere to obtain the quartz crucible blank; S2: Pretreatment of quartz crucible blank Perform plasma etching on the quartz crucible blank, then coat it with a composite slurry prepared by mixing quartz powder with a purity of 99.9%, nano-ceria and silica sol, dry it and sinter it to obtain the pretreated quartz crucible blank; S3: Preparation of corrosion-resistant quartz crucible Prepare ZrB 2 -SiC composite particles, and then mix the ZrB 2 -SiC composite particles, silica sol, Y 2 O 3 、deionized water to prepare a mixture, spray the mixture on the inner surface of the pretreated quartz crucible blank, then dry it and sinter it to prepare the corrosion-resistant quartz crucible.

[0009] Furthermore, the preparation of the quartz crucible blank in step S1 specifically includes the following steps: S1.1: Add 100-120 parts by weight of fused quartz 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 °C and stir and mix for 5-8 h, then dry and grind it to obtain the modified fused quartz 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 quartz powder, 5-8 parts by weight of silicon powder, 0.4-0.5 parts by weight of lactic acid, 0.5-1 part by weight of polyvinyl alcohol, 13-21 parts by weight of gel mixture and 29-43 parts by weight of deionized water into a polypropylene ball mill tank, add ball milling media according to the mass ratio of powder to zirconia balls of 1:2-3, then place the ball mill tank 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 mixed slurry with 0.6-1.5 parts by weight of ammonium persulfate and inject it into a mold, heat it to 50-60 °C, keep it warm for 15-18 min, gel and cure it, demold it to obtain a green body of the quartz crucible, sinter the green body of the quartz crucible under nitrogen atmosphere, and finally cool it with the furnace to obtain the quartz crucible blank.

[0010] Further, the pretreatment of the quartz crucible blank in step S2 specifically includes the following steps: S2.1: Use a mixed gas of Ar and O 2 mixed at a volume ratio of 4:1 to perform plasma etching on the inner surface of the quartz crucible blank at 500 - 600W for 20 - 30 minutes to obtain a quartz crucible blank with nano-grooves on the inner surface; S2.2: Mix 20 - 30 parts by weight of quartz powder with a purity of 99.9% and nano-ceria, and after mixing, place it in a zirconia ball milling tank with a liquid-solid mass ratio of 2 - 3:1. Ball mill at 300 - 400 r / min for 20 - 24 hours with absolute ethanol to obtain a slurry. Stir and mix 2 - 3 parts by weight of the slurry with 1 - 2 parts by weight of silica sol for 30 - 50 minutes to obtain a composite slurry; S2.3: Coat the composite slurry on the inner surface of the quartz crucible blank with nano-grooves, with a coating thickness of 0.1 - 0.3 mm. Then, naturally dry the coated quartz crucible blank at 25°C for 1 - 2 hours, and then place it at 130 - 150°C for 2 - 3 hours of drying. After drying, place it in a vacuum sintering at 800 - 820°C for 1 - 2 hours to obtain the pretreated quartz crucible blank.

[0011] Further, the preparation of the corrosion-resistant quartz crucible in step S3 specifically includes the following steps: S3.1: Mix ZrB powder with a purity of 99.5% and a particle size of 0.8 μm and SiC powder with a purity of 99.9% and a particle size of 1.2 μm at a molar ratio of 6:3 - 4. Then add 0.5 wt% phenolic resin, stir and mix to obtain a mixture, and perform spray granulation on the mixture to obtain ZrB 2 -SiC composite particles; 2 -SiC composite particles; S3.2: Put 50 - 60 parts by weight of ZrB 2 -SiC composite particles, 5 - 8 parts by weight of silica sol, 2 - 3 parts by weight of Y 2 O 3 in a zirconia ball milling tank and ball mill at 300 - 400 r / min for 20 - 24 hours to obtain a mixture. Spray the mixture on the inner surface of the pretreated quartz crucible blank, naturally dry it at 25°C for 1 - 2 hours, and then place it in a vacuum-sealed furnace. Introduce Ar with a purity of 99.99% into the furnace, and then sinter at 100 - 120 Pa, with an oxygen content in the furnace less than 0.01%, and at 1500 - 1700°C for 4 - 8 hours to obtain the corrosion-resistant quartz crucible.

[0012] Further, the sintering process in step S1.4 is specifically as follows: heating at a heating rate of 2 - 3 °C / min to 200 - 300 °C and holding for 1 - 2 h, then heating at a heating rate of 5 °C / min to 400 - 500 °C and holding for 1 - 2 h, then heating at a heating rate of 10 °C / min to 800 - 900 °C and holding for 1 - 2 h, and then heating at a heating rate of 10 °C / min to 1550 - 1600 °C and holding for 1 - 2 h.

[0013] Further, in step S2.2, nano - cerium oxide is added in a ratio of Ce / Si molar ratio of 1:20 - 22.

[0014] Further, in step S3.1, the spray granulation parameters are an inlet temperature of 180 - 200 °C, an outlet temperature of 80 - 90 °C, and an atomization pressure of 0.3 - 0.5 MPa.

[0015] In a second aspect, the present application provides a corrosion - resistant quartz crucible, which is prepared by the preparation process of a corrosion - resistant quartz crucible described in any one of the above.

[0016] Compared with the prior art, the present invention has at least the following beneficial effects: 1. In the present invention, the modified fused quartz powder and silicon powder are used for gel - casting to prepare the quartz crucible blank. The silane coupling agent hydrolyzes to generate silanol groups, which can undergo a condensation reaction with the hydroxyl groups on the surface of the fused quartz 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 binding force between the fused quartz powder and the subsequent organic substances. Then, sintering is carried out in a nitrogen atmosphere. When the temperature rises above the melting point of Si, Si 2 N 2 O is generated in - situ. The in - situ generated Si 2 N 2 O crystals inhibit the crystallization of fused quartz at high temperatures and reduce the crystallization rate of the quartz crucible.

[0017] 2. In the present invention, polyvinyl alcohol is introduced during the preparation of the quartz crucible blank. During the sintering process, intermolecular dehydration of polyvinyl alcohol occurs at 200 °C; once the temperature exceeds 200 °C, intramolecular dehydration begins, thereby forming a polymer with conjugated double bonds. Only when the temperature rises above 800 °C will polyvinyl alcohol be completely removed. During this period, polyvinyl alcohol undergoes viscous flow inside the product, which greatly strengthens the strength of the quartz network structure, inhibits the oxygen diffusion rate, and significantly reduces the crystallization amount because it is difficult to reach the Si / O stoichiometric ratio required for the precipitation of cristobalite crystals.

[0018] 3. The present invention uses Ar and O 2The mixed gas is used for plasma etching the inner surface of the quartz crucible blank to form nano-grooves, increasing the surface roughness, providing physical anchor points for subsequent coating adhesion, enhancing the bonding force between the coating and the substrate. At the same time, the chemical activity of the etched surface is improved, facilitating subsequent chemical reactions and coating adhesion. In the composite slurry of high-purity quartz powder and nano-ceria, Ce is uniformly embedded in the SiO 2 network through ball milling to form an amorphous structure, hindering the lattice rearrangement of SiO 2 , and CeO 2 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 to seal the pores. Nano-CeO 2 fills the quartz grain boundaries, thereby reducing the penetration path of molten silicon, and then effectively improving the corrosion resistance of the quartz crucible.

[0019] 4. Finally, the present invention adopts a composite coating of ZrB 2 -SiC composite particles and Y 2 O 3 . ZrB 2 has a high melting point, high hardness and good chemical stability. SiC also has excellent chemical corrosion resistance. The coating formed by the combination of the two can effectively resist the erosion of the silicon melt on the quartz crucible at high temperature and extend the service life of the quartz crucible. During the preparation of the silicon melt, the silicon melt is in a high-temperature state and has a certain chemical activity, and is prone to react with the crucible material. The ZrB 2 -SiC composite coating can form a strong barrier to prevent the direct contact between the silicon melt and the quartz crucible substrate, thereby reducing erosion. Both ZrB 2 and SiC have relatively high melting points and good high-temperature mechanical properties. The composite coating can maintain a stable structure and performance at high temperature and is not prone to deformation or damage. At the same time, the addition of Y 2 O 3 can further improve the high-temperature stability and oxidation resistance of the coating. During the nitriding sintering process, Y 2 O 3 interacts with other components to form a more dense and stable microstructure, enhancing the thermal shock resistance and oxidation resistance of the coating at high temperature, and ensuring the long-term use of the quartz crucible in a high-temperature environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings incorporated herein and constituting a part of the specification illustrate embodiments of the present invention and, together with the specification, are further used to explain the principles of the present invention and enable those skilled in the relevant art to implement and use the present invention.

[0021] Figure 1 FIG. is a process flow chart of a preparation process of a corrosion-resistant quartz crucible adopted in an embodiment of the present invention. Detailed implementation mode

[0022] The following combines the attached drawings and specific embodiments to describe in detail the preparation process of a corrosion-resistant quartz crucible provided by the present invention. At the same time, it is hereby explained that in order to make the embodiments more detailed, the following embodiments are the best and preferred embodiments. For some well-known technologies, those skilled in the art can also adopt other alternative methods for implementation; moreover, the attached drawings are only for more specifically describing the embodiments and are not intended to specifically limit the present invention.

[0023] Example 1 A preparation process of a corrosion-resistant quartz crucible is as Figure 1 shown, including the following steps: S1: Preparation of the quartz crucible blank S1.1: Add 100 parts by weight of fused quartz powder to 120 parts by weight of deionized water, then adjust the pH to 5, and then add 2 parts by weight of KH-550 silane coupling agent. After stirring and mixing evenly, a mixture is obtained. The mixture is placed at 70°C and stirred and mixed for 5 h, and then dried and ground to obtain modified fused quartz powder; S1.2: Mix 49 parts by weight of N,N-dimethylacrylamide and 1 part by weight of NN'-methylenebisacrylamide to obtain a gel mixture; S1.3: Place 69 parts by weight of modified fused quartz powder, 5 parts by weight of silicon powder, 0.4 part by weight of lactic acid, 0.5 part by weight of polyvinyl alcohol, 13 parts by weight of gel mixture and 29 parts by weight of deionized water in a polypropylene ball mill tank. Add the ball milling medium according to the mass ratio of the powder to zirconia balls of 1:2. Then place the ball mill tank in a planetary ball mill and ball mill at 600 r / min for 2 h to obtain a mixed slurry; S1.4: Mix the mixed slurry and 0.6 part by weight of ammonium persulfate and then inject them into a mold. Heat to 50°C and keep warm for 15 min. Gel curing and demolding are carried out to obtain a green body of the quartz crucible. The green body of the quartz crucible is sintered in a nitrogen atmosphere. The specific sintering process is as follows: Heat up to 200°C at a heating rate of 2°C / min and keep warm for 1 h, then heat up to 400°C at a heating rate of 5°C / min and keep warm for 1 h, then heat up to 800°C at a heating rate of 10°C / min and keep warm for 1 h, then heat up to 1550°C at a heating rate of 10°C / min and keep warm for 1 h, and finally cool with the furnace to obtain the quartz crucible blank; S2: Pretreatment of the quartz crucible blank S2.1: Use a mixed gas of Ar and O 2 mixed at a volume ratio of 4:1 to perform plasma etching on the inner surface of the quartz crucible blank at 500 W for 20 min to obtain a quartz crucible blank with nano-grooves on the inner surface; S2.2: Mix 20 parts by weight of quartz powder with a purity of 99.9% with nano-ceria, add nano-ceria in a ratio of Ce / Si molar ratio of 1:20. After mixing, place it in a zirconia ball milling tank with a liquid-solid mass ratio of 3:1, and ball mill for 20 h at 300 r / min using absolute ethanol to obtain a slurry. Stir and mix 2 parts by weight of the slurry with 1 part by weight of silica sol for 30 min to obtain a composite slurry; S2.3: Coat the inner surface of the quartz crucible blank containing nano-grooves with the composite slurry, with a coating thickness of 0.1 mm. Then, naturally dry the coated quartz crucible blank at 25 °C for 1 h, and then place it in an oven at 130 °C for 2 h. After drying, sinter it in a vacuum at 800 °C for 1 h to obtain a pretreated quartz crucible blank; S3: Preparation of corrosion-resistant quartz crucible S3.1: Mix ZrB powder with a purity of 99.5% and a particle size of 0.8 μm and SiC powder with a purity of 99.9% and a particle size of 1.2 μm in a molar ratio of 6:3. Then, add 0.5 wt% phenolic resin, stir and mix to obtain a mixture. Spray granulate the mixture at an inlet temperature of 180 °C, an outlet temperature of 80 °C, and an atomization pressure of 0.3 MPa to obtain ZrB 2 -SiC composite particles; 2 -SiC composite particles; S3.2: Place 50 parts by weight of ZrB 2 -SiC composite particles, 5 parts by weight of silica sol, 2 parts by weight of Y 2 O 3 , and 5 parts by weight of deionized water in a zirconia ball milling tank and ball mill at 300 r / min for 20 h to obtain a mixture. Spray the mixture on the inner surface of the pretreated quartz crucible blank, naturally dry it at 25 °C for 1 h, and then place it in a vacuum-sealed furnace. Introduce Ar with a purity of 99.99% into the furnace, and then sinter it at 100 Pa, with an oxygen content in the furnace less than 0.01%, and at 1500 °C for 4 h to obtain a corrosion-resistant quartz crucible.

[0024] Example 2 A preparation process for a corrosion-resistant quartz crucible, as Figure 1 shown, includes the following steps: S1: Preparation of quartz crucible blank S1.1: Add 120 parts by weight of fused quartz powder to 180 parts by weight of deionized water, then adjust the pH to 6, and then add 3 parts by weight of KH-550 silane coupling agent. After stirring and mixing evenly, obtain a mixture. Place the mixture in a stirrer at 70 °C and stir for 5 h, and then dry and grind it to obtain modified fused quartz powder; S1.2: Mix 63 parts by weight of N,N-dimethylacrylamide and 2 parts by weight of NN'-methylenebisacrylamide to obtain a gel mixture; S1.3: Place 76 parts by weight of modified fused quartz powder, 8 parts by weight of silicon powder, 0.5 part 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 into a polypropylene ball milling tank. Add ball milling media according to a mass ratio of 1:3 for the powder and zirconia balls. Then place the ball milling tank in a planetary ball mill and ball mill at 600 r / min for 2 h to obtain a mixed slurry; S1.4: Mix the mixed slurry with 1.5 parts by weight of ammonium persulfate and then inject it into a mold. Heat to 50 °C, keep warm for 15 min, gel and solidify, and demold to obtain a green body of a quartz crucible. Sinter the green body of the quartz crucible in a nitrogen atmosphere. The specific sintering process is as follows: Heat at a heating rate of 2 °C / min to 200 °C and keep warm for 1 h, then heat at a heating rate of 5 °C / min to 400 °C and keep warm for 1 h, then heat at a heating rate of 10 °C / min to 800 °C and keep warm for 1 h, then heat at a heating rate of 10 °C / min to 1550 °C and keep warm for 1 h, and finally cool with the furnace to obtain a quartz crucible blank; S2: Pretreatment of the quartz crucible blank S2.1: Use a mixed gas of Ar and O 2 mixed at a volume ratio of 4:1 to perform plasma etching on the inner surface of the quartz crucible blank at 500 W for 20 min to obtain a quartz crucible blank with nano-grooves on the inner surface; S2.2: Mix 30 parts by weight of quartz powder with a purity of 99.9% with nano-ceria, add nano-ceria according to a Ce / Si molar ratio of 1:22, place the mixture in a zirconia ball milling tank, with a liquid-solid mass ratio of 2:1, and ball mill with absolute ethanol at 300 r / min for 20 h to obtain a slurry. Stir and mix 3 parts by weight of the slurry with 2 parts by weight of silica sol for 30 min to obtain a composite slurry; S2.3: Coat the composite slurry on the inner surface of the quartz crucible blank with nano-grooves, with a coating thickness of 0.3 mm. Then naturally dry the coated quartz crucible blank at 25 °C for 1 h, then place it in an oven at 130 °C and dry for 2 h. After drying, place it in a vacuum furnace at 800 °C and sinter for 1 h to obtain a pretreated quartz crucible blank; S3: Preparation of a corrosion-resistant quartz crucible S3.1: Mix ZrB powder with a purity of 99.5% and a particle size of 0.8 μm and SiC powder with a purity of 99.9% and a particle size of 1.2 μm at a molar ratio of 6:4. Then add 0.5 wt% phenolic resin, stir and mix to obtain a mixture. Spray granulate the mixture at an inlet temperature of 180 °C, an outlet temperature of 80 °C, and an atomization pressure of 0.3 MPa to obtain ZrB 2 -SiC composite particles; 2 -SiC composite particles; S3.2: Place 60 parts by weight of ZrB2 -SiC composite particles, 8 parts by weight of silica sol, 3 parts by weight of Y 2 O 3 , 10 parts by weight of deionized water are placed in a zirconia ball mill pot and ball milled at 300 r / min for 20 h to obtain a mixed material. The mixed material is sprayed on the inner surface of the pretreated quartz crucible blank, naturally dried at 25 °C for 1 h, and then placed in a vacuum sealed furnace. Ar with a purity of 99.99% is introduced into the furnace. Then, sintering is carried out at 100 Pa, with the oxygen content in the furnace less than 0.01%, and at 1500 °C for 4 h to obtain a corrosion-resistant quartz crucible.

[0025] Example 3 A preparation process of a corrosion-resistant quartz crucible is as Figure 1 shown, including the following steps: S1: Preparation of the quartz crucible blank S1.1: Add 110 parts by weight of fused quartz powder to 150 parts by weight of deionized water, then adjust the pH to 5, and then add 2.5 parts by weight of KH-550 silane coupling agent. After stirring and mixing evenly, a mixture is obtained. The mixture is placed at 80 °C and stirred and mixed for 8 h, and then dried and ground to obtain modified fused quartz powder; 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; S1.3: Place 72 parts by weight of modified fused quartz powder, 6.5 parts by weight of silicon powder, 0.45 parts by weight of lactic acid, 0.7 parts by weight of polyvinyl alcohol, 18 parts by weight of the gel mixture, and 45 parts by weight of deionized water in a polypropylene ball mill pot. Add ball milling media according to a mass ratio of the powder to zirconia balls of 1:2.5. Then, place the ball mill pot in a planetary ball mill and ball mill at 700 r / min for 3 h to obtain a mixed slurry; S1.4: Mix the mixed slurry with 1 part by weight of ammonium persulfate and then inject it into a mold. Heat it to 60 °C, keep it warm for 18 min, gel and solidify, and demold to obtain a green body of the quartz crucible. The green body of the quartz crucible is sintered in a nitrogen atmosphere. The specific sintering process is as follows: Heat it to 300 °C at a heating rate of 3 °C / min and keep it warm for 2 h, then heat it to 500 °C at a heating rate of 5 °C / min and keep it warm for 2 h, then heat it to 900 °C at a heating rate of 10 °C / min and keep it warm for 2 h, then heat it to 1600 °C at a heating rate of 10 °C / min and keep it warm for 2 h, and finally cool it with the furnace to obtain the quartz crucible blank; S2: Pretreatment of the quartz crucible blank S2.1: Use Ar and O 2The mixed gas after mixing in a volume ratio of 4:1 is used to perform plasma etching on the inner surface of the quartz crucible blank at 600 W for 30 minutes to obtain a quartz crucible blank with nano-grooves on the inner surface; S2.2: Mix 25 parts by weight of quartz powder with a purity of 99.9% with nano-ceria, add nano-ceria in a Ce / Si molar ratio of 1:20, place the mixture in a zirconia ball milling tank, with a liquid-solid mass ratio of 2.5:1, and ball mill at 400 r / min for 24 h using absolute ethanol to obtain a slurry. Stir and mix 2.5 parts by weight of the slurry with 1.5 parts by weight of silica sol for 50 minutes to obtain a composite slurry; S2.3: Coat the composite slurry on the inner surface of the quartz crucible blank with nano-grooves, with a coating thickness of 0.1 mm. Then, naturally dry the coated quartz crucible blank at 25 °C for 2 h, and then place it in an oven at 150 °C for 3 h. After drying, sinter it in a vacuum at 820 °C for 2 h to obtain a pretreated quartz crucible blank; S3: Preparation of corrosion-resistant quartz crucible S3.1: Mix ZrB powder with a purity of 99.5% and a particle size of 0.8 μm and SiC powder with a purity of 99.9% and a particle size of 1.2 μm in a molar ratio of 6:3.5. Then, add 0.5 wt% phenolic resin, stir and mix to obtain a mixture. Spray granulate the mixture at an inlet temperature of 200 °C, an outlet temperature of 90 °C, and an atomization pressure of 0.5 MPa to obtain ZrB 2 -SiC composite particles; 2 S3.2: Place 55 parts by weight of ZrB 2 -SiC composite particles, 6.5 parts by weight of silica sol, 2.5 parts by weight of Y 2 O 3 in a zirconia ball milling tank and ball mill at 400 r / min for 24 h to obtain a mixture. Spray the mixture on the inner surface of the pretreated quartz crucible blank, naturally dry it at 25 °C for 2 h, and then place it in a vacuum-sealed furnace. Introduce Ar with a purity of 99.99% into the furnace, and then sinter it at 120 Pa, with an oxygen content in the furnace less than 0.01%, and 1700 °C for 8 h to obtain a corrosion-resistant quartz crucible.

[0026] Comparative Example 1 Compared with Example 1, the difference in Comparative Example 1 is that in Comparative Example 1, the silicon powder in step S1.3 is removed, and the sintering of the green quartz crucible in a nitrogen atmosphere in step S1.4 is modified to sintering the green quartz crucible in an argon atmosphere, and the rest of the steps remain unchanged to prepare a corrosion-resistant quartz crucible, denoted as Comparative Example 1.

[0027] Comparative Example 2 Compared with Example 1, the difference in Comparative Example 2 is that in Comparative Example 2, polyvinyl alcohol in step S1.3 was removed, and the other steps remained unchanged to prepare a corrosion-resistant quartz crucible, denoted as Comparative Example 2.

[0028] Comparative Example 3 Compared with Example 1, the difference in Comparative Example 3 is that in Comparative Example 3, step S2.1 was removed, and the quartz crucible blank containing nano-grooves in step S2.3 was replaced with a quartz crucible blank, and the other steps remained unchanged to prepare a corrosion-resistant quartz crucible, denoted as Comparative Example 3.

[0029] Comparative Example 4 Compared with Example 1, the difference in Comparative Example 4 is that in Comparative Example 4, steps S2.2 - S2.3 were removed, and the pre-treated quartz crucible blank in step S3.2 was replaced with a quartz crucible blank with nano-grooves on the inner surface, and the other steps remained unchanged to prepare a corrosion-resistant quartz crucible, denoted as Comparative Example 4.

[0030] Comparative Example 5 Compared with Example 1, the difference in Comparative Example 5 is that in Comparative Example 5, step S3 was removed, and a silicon nitride coating was sprayed on the surface of the pre-treated quartz crucible blank, and the other steps remained unchanged to prepare a corrosion-resistant quartz crucible, denoted as Comparative Example 5.

[0031] From the straight walls of the corrosion-resistant quartz crucibles prepared in Examples 1 - 3 and Comparative Examples 1 - 2, 5 quartz crucible specimens with a size of 100 mm × 100 mm were cut. The cut surfaces of the quartz crucible specimens were ground flat with silicon carbide, and then the quartz crucible specimens were soaked in 10% analytical pure hydrochloric acid for 20 min. After soaking, the quartz crucible specimens were washed 3 times with deionized water, then washed 3 times with absolute ethanol, and then wiped clean. Subsequently, the quartz crucible specimens were placed in an environment of 1500 °C and kept at a constant temperature for 8 h. After cooling to 25 °C, the specimens were observed by visual inspection, and the test results are shown in Table 1.

[0032] Table 1. Results of anti-crystallization determination

[0033] As can be seen from the data in Table 1, the corrosion-resistant quartz crucible prepared by the present invention by using the modified fused quartz powder and silicon powder through injection molding, then introducing polyvinyl alcohol, and sintering under a nitrogen atmosphere can reduce the crystallization phenomenon of the quartz crucible.

[0034] The quartz crucibles prepared in Examples 1 - 3 and Comparative Examples 3 - 5 were filled with high-temperature molten silicon melt, then heated to 1600 °C, kept for a certain time and then cooled, and then the above high-temperature melting operation was repeated 6 times, and then whether erosion, spalling or cracks appeared on the inner wall of the quartz crucible was observed. The measurement results are shown in Table 2.

[0035] Table 2. Results of the corrosion resistance measurement for Examples 1 - 3 and Comparative Examples 3 - 5

[0036] It can be seen from the data of Comparative Example 3 in Table 2 that the plasma etching of the inner surface of the quartz crucible blank with an Ar and O 2 mixed gas can enhance the bonding force between the coating and the substrate and reduce the peeling of the coating; it can be seen from the data of Comparative Example 4 and Comparative Example 5 that the coating prepared from the composite slurry of high-purity quartz powder and nano-cerium oxide effectively improves the corrosion resistance of the quartz crucible. The use of ZrB 2 -SiC composite particles and Y 2 O 3 composite coating can prevent the direct contact between the silicon melt and the quartz crucible substrate, thereby reducing erosion.

[0037] The above embodiments merely illustrate the principles and effects of the present invention and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by 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: The steps include: S1: Preparation of quartz crucible embryo The fused quartz powder was modified by KH-550 silane coupling agent, and then ball-milled with silicon powder, lactic acid, polyvinyl alcohol, gel mixture and deionized water, and then ammonium persulfate was added for solidification, and finally sintered in a nitrogen atmosphere to prepare a quartz crucible embryo; S2: Pretreatment of quartz crucible embryo Plasma etching is performed on the quartz crucible embryo body, and then a composite slurry prepared by mixing quartz powder with a purity of 99.9%, nano-cerium oxide and silica sol is coated, and then dried and sintered to obtain a pretreated quartz crucible embryo body; S3: Preparation of corrosion-resistant quartz crucible ZrB2-SiC composite particles are prepared, and then the ZrB2-SiC composite particles, silica sol, Y2O3 and deionized water are mixed to prepare a mixture, and the mixture is sprayed on the inner surface of the pretreated quartz crucible embryo, and then dried and sintered to prepare a corrosion-resistant quartz crucible.

2. The process for preparing a corrosion-resistant quartz crucible according to claim 1, characterized in that: Step S1: Preparation of a quartz crucible embryo, specifically comprising the following steps: S1.1: 100-120 parts by weight of fused quartz powder is added to 120-180 parts by weight of deionized water, and then the pH is adjusted to 5-6, and then 2-3 parts by weight of KH-550 silane coupling agent is added, and the mixture is stirred and mixed uniformly to obtain a mixture, and the mixture is placed at 70-80° C. and stirred and mixed for 5-8 hours, and then dried and ground to obtain modified fused quartz 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: 69-76 parts by weight of modified fused quartz powder, 5-8 parts by weight of silicon 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 are placed in a polypropylene ball mill, and ball milling media is added in a mass ratio of 1:2-3 between powder and zirconia ball, and then the ball mill is placed in a planetary ball mill, and ball milled at 600-700 r / min for 2-3 hours to obtain a mixed slurry; S1.4: Mix the mixed slurry and 0.6-1.5 parts by weight of ammonium persulfate and inject them into a mold, heat to 50-60°C, keep warm for 15-18 minutes, solidify the gel, demould to obtain a quartz crucible embryo, sinter the quartz crucible embryo in a nitrogen atmosphere, and finally cool it with the furnace to obtain a quartz crucible embryo.

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

4. The process for preparing a corrosion-resistant quartz crucible according to claim 3, characterized in that: Step S3: Preparation of corrosion-resistant quartz crucible, specifically comprising the following steps: S3.1: ZrB2 powder with a purity of 99.5% and a particle size of 0.8 μm and SiC powder with a purity of 99.9% and a particle size of 1.2 μm are mixed in a molar ratio of 6:3-4, and then 0.5 wt% of phenolic resin is added, and the mixture is stirred and mixed to obtain a mixture, and the mixture is spray granulated 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, and ball mill at 300-400r / min for 20-24h to obtain a mixture, spray the mixture on the inner surface of the pretreated quartz crucible blank, and naturally dry it at 25°C for 1-2h, then place it in a vacuum-tight furnace, and introduce Ar with a purity of 99.99% into the furnace, then sinter it at 100-120Pa, with an oxygen content in the furnace less than 0.01%, and 1500-1700°C for 4-8h to obtain a corrosion-resistant quartz crucible.

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

6. The process for preparing 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 process for preparing a corrosion-resistant quartz crucible according to claim 4, characterized in that: The spray granulation parameters in step S3.1 are as follows: inlet temperature 180-200°C, outlet temperature 80-90°C, and atomization pressure 0.3-0.5MPa.

8. A corrosion-resistant quartz crucible, characterized in that: The crucible is prepared by the preparation process of a corrosion-resistant quartz crucible according to any one of claims 1 to 7.

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