Corrosion-resistant and high-temperature-resistant composite quartz crucible and preparation method thereof

Abstract

The invention provides a corrosion-resistant and high-temperature-resistant composite quartz crucible and a preparation method thereof. The quartz crucible sequentially comprises the following laminated layers in parts by weight from inside to outside: 50-100 parts of an inner layer, 200-400 parts of a transition layer, 150-250 parts of a reinforcing layer and 40-80 parts of an outer layer, the preparation method comprises the following steps: forming layer by layer: sequentially adding inner-layer slurry, transition-layer powder, a reinforcement-layer prefabricated member and outer-layer slurry into a mold for forming; gradient drying is conducted, specifically, the formed crucible blank is put into a drying box to be subjected to gradient drying; and step-by-step sintering: putting the dried crucible blank into a high-temperature sintering furnace, carrying out step-by-step sintering, and cooling and demolding to obtain a crucible product. A composite protection system is designed and constructed through four layers of functionally graded materials, the prepared composite quartz crucible has excellent high temperature resistance, corrosion resistance and structural stability and can be applied to large-size semiconductor single crystal furnaces, and the engineering advantage of the preparation process is remarkable.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor single crystal growth equipment, in particular to a corrosion-resistant and high-temperature-resistant composite quartz crucible and a preparation method thereof. BACKGROUND

[0002] In the fields of semiconductors, photovoltaics, and high-temperature metallurgy, quartz crucibles, as core containers for holding molten silicon liquid, molten salt and other media, directly affect production efficiency and product quality in terms of high-temperature resistance, corrosion resistance and structural stability.

[0003] Traditional quartz crucibles mainly use high-purity quartz sand as raw material, and the crystal form is prone to phase change (such as quartz→cristobalite) at high temperatures, resulting in volume expansion (about 16%) and structural cracking. The long-term use temperature of conventional quartz crucibles is usually not more than 1550℃, and when repeatedly heated above 1000℃, the number of thermal shock cycles is only 2-3 times. In addition, alkali metal ions (such as Na + , K + ) in molten silicon liquid easily penetrate into the interior through pores, causing interfacial corrosion.

[0004] During the growth of semiconductor single crystals, impurities (such as boron, phosphorus) in the molten silicon liquid react with the quartz crucible to form volatile compounds, causing erosion of the inner wall of the crucible and contamination of the silicon material. In photovoltaic ingot furnaces, the corrosion rate of high-temperature molten salt (such as fluoride) on the crucible can reach 1.2% / 24h, significantly shortening the service life. The apparent porosity of conventional crucibles is generally ≥10%, which cannot effectively block the intrusion of corrosive media.

[0005] Multi-layer structure crucibles often have interfacial stress at high temperatures due to the mismatch of the thermal expansion coefficients of each layer (such as the difference in thermal expansion coefficient between the inner quartz layer and the outer ceramic layer >10%), leading to interlayer peeling. Traditional processes use simple physical stacking, and the interfacial bonding strength is ≤10MPa, which cannot meet the long-term high-temperature service requirements.

[0006] Pure quartz structure crucibles have a sharp drop in flexural strength at temperatures above 1200℃, and are prone to deformation or rupture. The service life of a 36-inch crucible commonly used in the photovoltaic field is only 300-400 hours, and the replacement cost accounts for more than 2% of the cost of silicon wafer production. In addition, the structural stability problem brought about by large size (such as 40 inches) further exacerbates this contradiction.

[0007] Therefore, the present application is proposed. SUMMARY

[0008] The purpose of this invention is to address the technical problems of crystal transformation, interlayer delamination, and structural deformation of traditional quartz crucibles under high-temperature corrosive environments. It provides a corrosion-resistant and high-temperature resistant composite quartz crucible and its preparation method. By designing and constructing a composite protection system through four layers of functionally graded materials, the resulting composite quartz crucible has excellent high-temperature resistance, corrosion resistance, and structural stability. It can be adapted to large-size semiconductor single crystal furnace applications, and the preparation process has significant engineering advantages.

[0009] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: A corrosion-resistant and high-temperature resistant composite quartz crucible comprises, from the inside out, the following layers in parts by weight: an inner layer of 50-100 parts, a transition layer of 200-400 parts, a reinforcing layer of 150-250 parts, and an outer layer of 40-80 parts.

[0010] Furthermore, the raw materials of the inner layer include the following components by weight: 5-10 parts nano ZrO2, 3-5 parts B4C, 2-4 parts SiC, 80-85 parts high-purity quartz sand, 8-12 parts silica sol, and 1-3 parts BaSiO3.

[0011] Furthermore, the raw materials of the transition layer include the following components by weight: 75-80 parts quartz sand, 10-15 parts H3BO3, 5-8 parts Al2O3, and 3-5 parts BaB2O4.

[0012] Furthermore, the reinforcing layer is a quartz fiber cloth that has been impregnated with resin and then laminated.

[0013] Furthermore, the raw materials of the outer layer include the following components by weight: 70-80 parts of quartz sand, 30-34.3 parts of composite filler, and 15-20 parts of silica sol; the composite filler includes the following components by weight: 5-10 parts of carbon powder, 5-8 parts of BN, and 5-8 parts of BP.

[0014] A method for preparing a corrosion-resistant and high-temperature-resistant composite quartz crucible includes the following steps: Step S1: Layer-by-layer molding. The inner layer slurry, transition layer powder, reinforcing layer preform, and outer layer slurry are sequentially added into the mold to form a crucible blank. Step S2, Gradient Drying: Place the formed crucible blank into a drying oven for gradient drying; Step S3, Segmented sintering: The dried crucible blank is placed in a high-temperature sintering furnace for segmented sintering. Finally, it is cooled to room temperature with the furnace and demolded to obtain the crucible product.

[0015] Furthermore, the layer-by-layer forming method in step S1 is as follows: Step S1.1: First, pour the inner layer slurry into the mold and vibrate it to form the shape; Step S1.2: Evenly spread the transition layer powder on the inner surface, with a thickness of 2~3mm, and gently compact it; Step S1.3: Cover the reinforcing layer preform onto the transition layer powder, ensuring close adhesion between the preform and the transition layer powder; Step S1.4: Pour the outer layer slurry into the mold, cover it on the reinforcing layer preform, and vibrate it again to form the mold.

[0016] Furthermore, the preparation method of the inner layer slurry includes the following steps: a. Add 5-10 parts of nano ZrO2, 3-5 parts of B4C, and 2-4 parts of SiC to deionized water and ultrasonically disperse to form a uniform pre-dispersed slurry with a particle size ≤100nm. b. Add 80-85 parts of high-purity quartz sand to a planetary ball mill, pour in the pre-dispersed slurry prepared in step a, and 8-12 parts of silica sol and 1-3 parts of BaSiO3. Ball mill to make the dispersion uniformity of each component ≥98%. c. The mixture is transferred to a constant temperature aging kettle and left to stand, forming a thixotropic paste-like inner layer slurry with a viscosity of 5000~8000 mPa•s.

[0017] Furthermore, the method for preparing the transition layer powder includes the following steps: a. Add 75-80 parts of quartz sand, 10-15 parts of H3BO3, 5-8 parts of Al2O3, and 3-5 parts of BaB2O4 to a high-speed mixer and mix until the particle size D90 ≤ 100 μm and the composition uniformity deviation < 2%; b. Add granulating agent and spray dry to form spherical particles of 0.3~0.8mm; c. Pre-calcine the spherical particles prepared in step b in a muffle furnace to allow boric acid to initially soften and coat the quartz particles. d. After cooling the pre-burned particles from step c, spray the surface with KH-560 ethanol solution and dry at room temperature to form a micron-level interfacial active layer, thus obtaining the transition layer powder.

[0018] Furthermore, the method for preparing the reinforcing layer preform includes the following steps: a. Immerse and dry the quartz fiber cloth in KH-550 ethanol solution to graft silane coupling agent onto the fiber surface. b. Impregnation and Lamination: The activated fiber cloth is passed through an impregnation tank. The viscosity of the silicone resin adhesive in the impregnation tank is 300~500 mPa•s, and the adhesive application rate is controlled at 90~110 g / m. 2 The solvent is removed in an infrared drying oven until it reaches a semi-cured state; 3 to 5 layers are stacked in a 0° / 90° cross pattern to form a reinforcing layer preform. c. Hot pressing and curing molding: The blank is placed in a hot press and hot-pressed for 5 hours. The curing process is carried out by raising the temperature in stages and then keeping it at a constant temperature to form a preform with a reinforcing layer thickness of 0.4~0.6mm and a fiber volume fraction of ≥60%.

[0019] Furthermore, the method for preparing the outer layer slurry includes the following steps: a. Add 70-80 parts of quartz sand to KH-570 ethanol solution and stir at a constant temperature to graft silane coupling agent onto the surface of the quartz sand. b. Dry until the moisture content is <0.3% to form an active surface; c. Prepare composite filler: Add 5-10 parts carbon powder, 5-8 parts BN, and 5-8 parts BP to a high-speed disperser to form a composite filler with an average particle size ≤8μm; add stearic acid at 2% of the mass of the composite filler as a dispersing aid. d. Mix modified quartz sand and composite filler in a 7:3 ratio, add 15-20 parts silica sol and deionized water, and stir until the viscosity of the Forecast 4 cup is 60-80s to form an outer slurry with a solid content ≥75%.

[0020] Furthermore, the gradient drying method in step S2 is as follows: first, dry at 50~80℃ for 2~4 hours to remove surface moisture; then dry at 100~150℃ for 4~6 hours to allow the moisture in the blank to fully evaporate.

[0021] Furthermore, in step S3, the segmented sintering adopts gradient sintering. The gradient sintering method is as follows: first, heat to 600-800℃ at a heating rate of 5-10℃ / min and hold for 1-2 hours to remove organic matter and binder from the green body; then heat to 1600-1700℃ at a heating rate of 10-15℃ / min and hold for 3-5 hours.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention relates to a corrosion-resistant and high-temperature-resistant composite quartz crucible and its preparation method. Through four-layer gradient material and process innovation, a high-performance composite quartz crucible is constructed: Material design: The inner layer is based on high-purity quartz sand, with the addition of nano-zirconia (30% improvement in thermal shock resistance), boron carbide (45% reduction in corrosion resistance), and silica sol (60% increase in strength); The transition layer uses a boric acid-alumina system to reduce the sintering temperature by 200℃, improving the interfacial bonding force by 60%; The reinforcing layer uses quartz fiber cloth (80% improvement in deformation resistance) combined with segmented curing, achieving a high-temperature strength retention rate of ≥90%; The outer layer is modified with silane and composited with carbon powder / BN / BP to form a double corrosion-resistant layer (60% reduction in alkali metal penetration); Process innovation: The "layer-by-layer forming-gradient sintering" process is adopted to achieve a four-layer nested structure. During sintering, a mullite composite crystal phase is generated (thermal shock resistance ≥5 times). Combined with interfacial sandblasting and gradient composition technology between layers, the interlayer bonding force is improved by 120%, solving the peeling problem.

[0023] 2. This invention relates to a corrosion-resistant and high-temperature resistant composite quartz crucible, which constructs a composite protection system through a four-layer functionally graded material design: the inner layer uses high-purity quartz sand as a base, introducing zirconium dioxide (inhibiting crystal transformation and improving thermal shock resistance by 30%) and boron carbide (forming a high-temperature protective film and reducing the erosion rate by 45%), combined with a silica sol bonding system (apparent porosity ≤4%, flexural strength increased by 60%), to create a high-purity corrosion-resistant core layer; the transition layer uses a boric acid-alumina-barium borate system (sintering temperature reduced by 200℃, interface bonding strength increased by 60%) to solve the interlayer stress problem; the reinforcing layer uses quartz fiber cloth to construct a three-dimensional skeleton (deformation resistance increased by 80%), and the segmented curing process ensures a high-temperature strength retention rate ≥90%; the outer layer uses silane-modified quartz sand and carbon powder / BN / BP composite filler (apparent porosity ≤7%, alkali metal ion penetration depth reduced by 60%) to form a dual corrosion-resistant layer of "physical barrier + chemical protection".

[0024] 3. The method for preparing corrosion-resistant and high-temperature resistant composite quartz crucibles of the present invention adopts a process chain of "layer-by-layer forming - gradient sintering - interface strengthening": vibration forming of inner layer slurry, roughening of the interface of transition layer powder, preforming of orthogonal stacking of reinforcing layer, and molding of outer layer high solid content slurry, realizing a four-layer physical nesting of "slurry-powder-fiber-slurry"; the sintering process uses low-temperature slow glue removal, medium-temperature glass phase formation, and high-temperature eutectic sintering to generate mullite / barium feldspar composite crystal phase at the interface (resistant to thermal shock cycles ≥5 times); supplemented by interlayer interface sandblasting and gradient composition transition technology, the interlayer element diffusion depth is increased from 10μm to 50μm, the interface damage load is increased by 120%, and the problem of interlayer delamination in traditional crucibles is solved.

[0025] 4. The present invention provides a corrosion-resistant and high-temperature resistant composite quartz crucible with improved crucible reusability (from 3 times to 8 times), a maximum operating temperature of 1700℃ (long-term), acid resistance weight loss ≤0.3% (75% reduction), thermal shock resistance ≥5 cycles (66.7% increase), interlayer bonding strength ≥25MPa (150% improvement), and semiconductor application lifespan exceeding 500 hours (150% improvement).

[0026] 5. The method for preparing corrosion-resistant and high-temperature resistant composite quartz crucible of the present invention has significant engineering advantages: sintering energy consumption is reduced by 20%, batch performance fluctuation is ≤5%, it is compatible with high-end equipment such as semiconductor single crystal furnace (dimensional accuracy error ≤0.5%) and photovoltaic ingot casting furnace, and by reducing the impurity contamination rate (from 0.1% to 0.03%), it helps downstream industries improve the yield rate by 5% and reduce costs by 40%.

[0027] 6. The corrosion-resistant and high-temperature resistant composite quartz crucible of the present invention can be adapted to semiconductor single crystal furnaces (including large-size single crystal furnaces) with high precision, and can be extended to extreme scenarios such as high-temperature molten salt electrolysis and strong corrosion catalysis, filling the application gap of traditional quartz crucibles. Attached Figure Description

[0028] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the cross-sectional structure of the corrosion-resistant and high-temperature-resistant composite quartz crucible of the present invention. Detailed Implementation

[0030] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0031] A corrosion-resistant and high-temperature resistant composite quartz crucible comprises, from the inside out, the following layers in parts by weight: inner layer 50-100 parts, transition layer 200-400 parts, reinforcing layer 150-250 parts, and outer layer 40-80 parts; Preferably, the raw materials of the inner layer include the following components by weight: 5-10 parts nano ZrO2, 3-5 parts B4C, 2-4 parts SiC, 80-85 parts high-purity quartz sand, 8-12 parts silica sol, and 1-3 parts BaSiO3. The inner layer comprises zirconium dioxide, boron carbide, silica sol, silicon carbide, and barium silicate. High-purity quartz sand ensures the high purity of the inner layer of the crucible, reducing the impact of impurities on the crucible's performance. Nano-sized zirconium dioxide particles have excellent high-temperature resistance and chemical stability, which can improve the high-temperature resistance and corrosion resistance of the inner layer. Boron carbide particles have high hardness and good wear resistance, which can enhance the wear resistance of the inner layer. At the same time, they can form a protective film at high temperatures, further improving corrosion resistance. Preferably, the method for preparing the inner layer slurry includes the following steps: a. Add 5-10 parts of nano ZrO2, 3-5 parts of B4C, and 2-4 parts of SiC to deionized water at a solid-liquid ratio of 1:3, and disperse using an ultrasonic disperser (1000W power) for 40 minutes to form a uniform pre-dispersed slurry with a particle size ≤100nm. b. Add 80-85 parts of high-purity quartz sand to a planetary ball mill, pour in the pre-dispersed slurry prepared in step a, 8-12 parts of silica sol, and 1-3 parts of BaSiO3, and ball mill at 250 rpm for 6 hours. Use zirconia ball milling media and a ball-to-material ratio of 4:1 to ensure that the dispersion uniformity of each component is ≥98%. c. The mixture is transferred to a 45°C constant temperature aging kettle and left to stand for 16 hours to promote the full hydrolysis and condensation of the silica sol, forming a thixotropic paste-like inner layer slurry with a viscosity of 5000~8000 mPa•s, including but not limited to 5000 mPa•s, 6000 mPa•s, 7000 mPa•s, and 8000 mPa•s. Preferably, the raw materials for the transition layer include the following components by weight: 75-80 parts quartz sand, 10-15 parts H3BO3, 5-8 parts Al2O3, and 3-5 parts BaB2O4; The transition layer powder is composed of quartz sand, boric acid (H3BO3), alumina (Al2O3), and barium borate (BaB2O4). Boric acid, as a sintering aid, can lower the sintering temperature of quartz sand and promote the bonding between particles. Alumina can improve the high-temperature resistance and mechanical strength of the transition layer, and at the same time, it plays a role in connecting the inner layer and the reinforcing layer, making the bonding between the layers tighter and reducing the possibility of interlayer delamination. Preferably, the method for preparing the transition layer powder includes the following steps: a. Add 75-80 parts of quartz sand, 10-15 parts of H3BO3, 5-8 parts of Al2O3, and 3-5 parts of BaB2O4 to a high-speed mixer, and mix at 2000 rpm for 30 minutes until the particle size D90 ≤ 100 μm and the composition uniformity deviation < 2%; b. Add 5% polyvinyl alcohol aqueous solution by weight of powder as a granulating agent, and dry it in a spray dryer with an inlet air temperature of 150℃ to make spherical particles of 0.3~0.8mm, including but not limited to 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, and 0.8mm. c. Pre-calcine the spherical particles prepared in step b in a muffle furnace at 850°C for 2 hours to allow boric acid to initially soften and coat the quartz particles. d. After cooling the pre-burned particles in step c, spray the surface with 0.5wt% silane coupling agent (KH-560, γ―(2,3-epoxypropoxy)propyltrimethoxysilane) ethanol solution, and dry at room temperature for 2 hours to form a micron-level interfacial active layer, reducing the contact angle by 40° to obtain the transition layer powder. Preferably, the reinforcing layer is a quartz fiber cloth that has been impregnated with resin and then laminated; Preferably, the method for preparing the reinforcing layer preform includes the following steps: a. Immerse the quartz fiber cloth in a 5wt% KH-550 (γ-aminopropyltriethoxysilane) ethanol solution (ethanol:water (mass ratio) = 8:2) for 20 minutes, and dry it at 130℃ for 40 minutes to graft silane coupling agent onto the fiber surface, increasing the surface hydroxyl density by 3 times, thus obtaining activated fiber cloth. b. Impregnation and Lamination: The activated fiber cloth is passed through an impregnation tank. The viscosity of the silicone resin adhesive in the impregnation tank is 300-500 mPa•s, including but not limited to 300 mPa•s, 400 mPa•s, and 500 mPa•s. The amount of adhesive applied is controlled at 90-110 g / m. 2 including but not limited to 90g / m 2 100g / m 2 110g / m 2 The material is dried in an infrared drying oven at 80°C for 5 minutes to remove the solvent and reach a semi-cured state; then 3 to 5 layers are stacked in a 0° / 90° cross pattern, including but not limited to 3, 4, and 5 layers, to form a reinforcing layer preform. c. Hot pressing and curing: The preform is placed in a hot press and cured at 160℃ and 2.0MPa pressure for 5 hours. The curing process is divided into three stages: 50℃ for 1 hour, 100℃ for 1 hour, and 160℃ for 1 hour, forming a reinforcing layer preform with a thickness of 0.4~0.6mm (including but not limited to 0.4mm, 0.5mm, and 0.6mm) and a fiber volume fraction ≥60%. The reinforcing layer includes quartz fiber, silicone resin adhesive, and silane coupling agent. The quartz fiber cloth has the characteristics of high strength and high temperature resistance, which can improve the overall mechanical strength of the crucible and prevent the crucible from deforming at high temperature. The silicone resin adhesive has good high temperature resistance and adhesion, which firmly bonds the quartz fiber cloth together to form a tough reinforcing layer. Preferably, the raw materials for the outer layer include the following components by weight: 70-80 parts quartz sand, 30-34.3 parts composite filler, and 15-20 parts silica sol; The composite filler comprises the following components by weight: 5-10 parts carbon powder, 5-8 parts BN, and 5-8 parts BP; The outer layer contains quartz sand, carbon powder, silane coupling agent, boron nitride (BN), and boron phosphide (BP). The silane coupling agent modifies the surface of the quartz sand, improving the compatibility and adhesion between the quartz sand and other components, making the outer layer denser and effectively blocking the intrusion of corrosive media, while also enhancing the high-temperature resistance of the outer layer. Preferably, the method for preparing the outer layer slurry includes the following steps: a. Add 70-80 parts of quartz sand to 3-5 parts of KH-570 (γ-methacryloyloxypropyltrimethoxysilane) ethanol solution (concentration 3%) and treat in a constant temperature stirred tank at 65℃ for 2.5 hours to graft silane coupling agent onto the surface of the quartz sand. b. Dry at 110℃ until the moisture content is <0.3% to form an active surface, increasing the surface energy by 25%; c. Prepare composite filler: Add 5-10 parts carbon powder, 5-8 parts BN, and 5-8 parts BP to a high-speed disperser and disperse at 2500 rpm for 20 minutes to form a composite filler with an average particle size ≤8μm; add 2% stearic acid by mass of the composite filler as a dispersing aid to prevent agglomeration. d. Mix modified quartz sand and composite filler in a 7:3 ratio, add 15-20 parts silica sol (40% solid content) and an appropriate amount of deionized water, and stir until the mixture has suitable fluidity. The viscosity at Forecast cup 4 should be 60-80s, including but not limited to 60s, 70s, and 80s, to form an outer slurry with a solid content ≥75%. A method for preparing a corrosion-resistant and high-temperature-resistant composite quartz crucible includes the following steps: Step S1, Mold preparation: Use a stainless steel mold, and coat the inner wall of the mold with a layer of release agent, such as silicone oil, to facilitate the demolding of the crucible product; Step S2: Layer-by-layer molding. The inner layer slurry, transition layer powder, reinforcing layer preform, and outer layer slurry are sequentially added into the mold to form a crucible blank. Step S3, Gradient Drying: Place the formed crucible blank into a drying oven for gradient drying. First, dry at 50~80℃ (including but not limited to 50℃, 60℃, 70℃, 80℃) for 2~4 hours (including but not limited to 2 hours, 3 hours, 4 hours) to remove surface moisture; then dry at 100~150℃ (including but not limited to 100℃, 110℃, 120℃, 130℃, 140℃, 150℃) for 4~6 hours (including but not limited to 4 hours, 5 hours, 6 hours) to allow the moisture inside the blank to fully evaporate. Step S4, Segmented Sintering: Segmented sintering adopts gradient sintering. The dried crucible blank is placed in a high-temperature sintering furnace for segmented sintering: First, it is heated to 600~800℃ (including but not limited to 600℃, 700℃, 800℃, 9℃, 10℃) at a heating rate of 5~10℃ / min (including but not limited to 5℃ / min, 6℃ / min, 7℃ / min, 8℃ / min, 9℃ / min, 10℃ / min), and held at that temperature for 1~2 hours (including but not limited to 1 hour, 1.5 hours, 2 hours). Remove organic matter and binder from the green body; then heat to 1600~1700℃ at a heating rate of 10~15℃ / min (including but not limited to 10℃ / min, 11℃ / min, 12℃ / min, 13℃ / min, 14℃ / min, 15℃ / min), including but not limited to 1600℃, 1650℃, 1700℃, and hold for 3~5 hours, including but not limited to 3 hours, 4 hours, 5 hours, to fully sinter and fuse the materials of each layer; finally, cool to room temperature in the furnace. Step S5, Demolding and Cleaning: Remove the sintered crucible product from the mold, perform surface trimming, and remove burrs and uneven parts from the edges; then perform ultrasonic cleaning to remove impurities and residues from the surface; finally, conduct quality inspection on the crucible product to ensure that the product meets the requirements. Preferably, the layer-by-layer forming method in step S2 is as follows: Step S2.1: First, pour the inner layer slurry into the mold and vibrate it to form the mold. The vibration frequency is 50~100Hz, including but not limited to 50Hz, 60Hz, 70Hz, 80Hz, 90Hz, and 100Hz. The vibration time is 5~10 minutes, including but not limited to 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, and 10 minutes, so that the inner layer slurry fills the mold and removes air bubbles. Step S2.2: Evenly spread the transition layer powder on the inner surface, with a thickness of 2~3mm, and gently compact it; Step S2.3: Cover the reinforcing layer preform onto the transition layer powder, ensuring close adhesion between the preform and the transition layer powder; Step S2.4: Pour the outer layer slurry into the mold, cover it on the reinforcing layer preform, and vibrate it again to form the mold. The vibration frequency is 50~100Hz, including but not limited to 50Hz, 60Hz, 70Hz, 80Hz, 90Hz, and 100Hz. The vibration time is 5~10 minutes, including but not limited to 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, and 10 minutes. Preferably, the quality inspection includes visual inspection, dimensional measurement, high temperature resistance test, and corrosion resistance test.

[0032] Example 1 A method for preparing a corrosion-resistant and high-temperature-resistant composite quartz crucible includes the following steps: 1. Preparation of the inner layer slurry, including the following steps: a. Add 5 parts nano ZrO2, 3 parts B4C, and 2 parts SiC to deionized water at a solid-liquid ratio of 1:3, and disperse using an ultrasonic disperser (1000W power) for 40 minutes to form a uniform pre-dispersed slurry with a particle size ≤100nm. b. Add 80 parts of high-purity quartz sand to a planetary ball mill, pour in the pre-dispersed slurry prepared in step a, 8 parts of silica sol, and 1 part of BaSiO3, and ball mill at 250 rpm for 6 hours. Use zirconia ball milling media and a ball-to-material ratio of 4:1 to ensure that the dispersion uniformity of each component is ≥98%. c. The mixture is transferred to a 45°C constant temperature aging kettle and left to stand for 16 hours to promote the full hydrolysis and condensation of the silica sol, forming a thixotropic paste-like inner layer slurry with a viscosity of 5000 mPa•s. 2. Preparation of transition layer powder, including the following steps: a. Add 75 parts of quartz sand, 10 parts of H3BO3, 5 parts of Al2O3, and 3 parts of BaB2O4 to a high-speed mixer, mix at 2000 rpm for 30 minutes until the particle size D90 ≤ 100 μm and the composition uniformity deviation < 2%; b. Add 5% (by weight of powder) of polyvinyl alcohol aqueous solution as a granulating agent, and dry it in a spray dryer with an inlet air temperature of 150℃ to produce 0.3mm spherical granules. c. Pre-calcine the spherical particles prepared in step b in a muffle furnace at 850°C for 2 hours to allow boric acid to initially soften and coat the quartz particles. d. After cooling the pre-burned particles in step c, spray the surface with 0.5wt% silane coupling agent KH-560 ethanol solution and dry at room temperature for 2 hours to form a micron-level interfacial active layer, reducing the contact angle by 40° to obtain the transition layer powder. 3. Prepare the reinforcing layer preform, including the following steps: a. Immerse the quartz fiber cloth in a 5wt% KH-550 ethanol solution (ethanol:water (mass ratio) = 8:2) for 20 minutes, and dry it at 130℃ for 40 minutes to graft silane coupling agent onto the fiber surface, increasing the surface hydroxyl density by 3 times, thus obtaining activated fiber cloth. b. Impregnation and Lamination: The activated fiber cloth is passed through an impregnation tank. The viscosity of the silicone resin adhesive in the impregnation tank is 300 mPa•s, and the amount of adhesive applied is controlled at 110 g / m. 2 The material is dried in an infrared drying oven at 80°C for 5 minutes to remove the solvent and reach a semi-cured state; then three layers are stacked in a 0° / 90° cross pattern to form a reinforcing layer preform. c. Hot pressing and curing: The preform is placed in a hot press and cured at 160℃ and 2.0MPa for 5 hours. The curing process is divided into three stages: 50℃ for 1 hour, 100℃ for 1 hour, and 160℃ for 1 hour, forming a preform with a 0.4mm thick reinforcing layer and a fiber volume fraction ≥60%. 4. Preparation of the outer layer slurry, including the following steps: a. Add 70 parts of quartz sand to 3 parts of KH-570 ethanol solution (concentration 3%) and treat in a constant temperature stirred tank at 65℃ for 2.5 hours to graft silane coupling agent onto the surface of the quartz sand. b. Dry at 110℃ until the moisture content is <0.3% to form an active surface, increasing the surface energy by 25%; c. Prepare composite filler: Add 5 parts carbon powder, 5 parts BN, and 5 parts BP to a high-speed disperser and disperse at 2500 rpm for 20 minutes to form a composite filler with an average particle size ≤8μm; add 2% stearic acid by mass of the composite filler as a dispersing aid to prevent agglomeration. d. Mix modified quartz sand and composite filler in a 7:3 ratio, add 15 parts silica sol (40% solid content) and an appropriate amount of deionized water, stir until the mixture has suitable fluidity, and the viscosity at Forte 4 cup is 60s, to form an outer slurry with a solid content ≥75%; 5. Mold preparation: Stainless steel molds are used, and the inner wall of the mold is coated with a release agent, such as silicone oil, to facilitate the demolding of the crucible products; 6. Layer-by-layer molding: The inner layer slurry, transition layer powder, reinforcing layer preform, and outer layer slurry are sequentially added into the mold to form the crucible blank. 7. Gradient drying: Place the formed crucible blank into a drying oven for gradient drying. First, dry at 50℃ for 4 hours to remove surface moisture; then dry at 100℃ for 6 hours to allow the moisture inside the blank to evaporate completely. 8. Segmented sintering: The dried crucible blank is placed in a high-temperature sintering furnace for segmented sintering: First, it is heated to 600℃ at a heating rate of 5℃ / min and held for 2 hours to remove organic matter and binder from the blank; then it is heated to 1600℃ at a heating rate of 10℃ / min and held for 5 hours to fully sinter and fuse the materials of each layer; finally, it is cooled to room temperature with the furnace. 9. Demolding and Cleaning: Remove the sintered crucible product from the mold, perform surface trimming, and remove burrs and uneven parts from the edges; then perform ultrasonic cleaning to remove impurities and residues from the surface; finally, conduct quality inspection on the crucible product to ensure that the product meets the requirements.

[0033] Example 2 A method for preparing a corrosion-resistant and high-temperature-resistant composite quartz crucible includes the following steps: 1. Preparation of the inner layer slurry, including the following steps: a. Add 8 parts nano ZrO2, 4 parts B4C, and 3 parts SiC to deionized water at a solid-liquid ratio of 1:3, and disperse using an ultrasonic disperser (1000W power) for 40 minutes to form a uniform pre-dispersed slurry with a particle size ≤100nm. b. Add 82 parts of high-purity quartz sand to a planetary ball mill, pour in the pre-dispersed slurry prepared in step a, 10 parts of silica sol, and 2 parts of BaSiO3, and ball mill at 250 rpm for 6 hours. Use zirconia ball milling media and a ball-to-material ratio of 4:1 to ensure that the dispersion uniformity of each component is ≥98%. c. The mixture is transferred to a 45°C constant temperature aging kettle and left to stand for 16 hours to promote the full hydrolysis and condensation of the silica sol, forming a thixotropic paste-like inner layer slurry with a viscosity of 6000 mPa•s. 2. Preparation of transition layer powder, including the following steps: a. Add 78 parts of quartz sand, 13 parts of H3BO3, 7 parts of Al2O3, and 4 parts of BaB2O4 to a high-speed mixer, mix at 2000 rpm for 30 minutes until the particle size D90 ≤ 100 μm and the composition uniformity deviation < 2%; b. Add 5% (by weight of powder) of polyvinyl alcohol aqueous solution as a granulating agent, and dry it in a spray dryer with an inlet air temperature of 150℃ to form 0.5mm spherical granules. c. Pre-calcine the spherical particles prepared in step b in a muffle furnace at 850°C for 2 hours to allow boric acid to initially soften and coat the quartz particles. d. After cooling the pre-burned particles in step c, spray the surface with 0.5wt% silane coupling agent KH-560 ethanol solution and dry at room temperature for 2 hours to form a micron-level interfacial active layer, reducing the contact angle by 40° to obtain the transition layer powder. 3. Prepare the reinforcing layer preform, including the following steps: a. Immerse the quartz fiber cloth in a 5wt% KH-550 ethanol solution (ethanol:water (mass ratio) = 8:2) for 20 minutes, and dry it at 130℃ for 40 minutes to graft silane coupling agent onto the fiber surface, increasing the surface hydroxyl density by 3 times, thus obtaining activated fiber cloth. b. Impregnation and Lamination: The activated fiber cloth is passed through an impregnation tank. The viscosity of the silicone resin adhesive in the impregnation tank is 400 mPa•s, and the adhesive application rate is controlled at 100 g / m. 2 The material is dried in an infrared drying oven at 80°C for 5 minutes to remove the solvent and reach a semi-cured state; then four layers are stacked in a 0° / 90° cross pattern to form a reinforcing layer preform. c. Hot pressing and curing: The preform is placed in a hot press and cured at 160℃ and 2.0MPa pressure for 5 hours. The curing process is divided into three stages: 50℃ for 1 hour, 100℃ for 1 hour, and 160℃ for 1 hour, forming a 0.5mm thick reinforcing layer preform with a fiber volume fraction ≥60%. 4. Preparation of the outer layer slurry, including the following steps: a. Add 75 parts of quartz sand to 4 parts of KH-570 ethanol solution (concentration 3%) and treat in a constant temperature stirred tank at 65℃ for 2.5 hours to graft silane coupling agent onto the surface of the quartz sand. b. Dry at 110℃ until the moisture content is <0.3% to form an active surface, increasing the surface energy by 25%; c. Prepare composite filler: Add 8 parts carbon powder, 6 parts BN and 7 parts BP to a high-speed disperser and disperse at 2500 rpm for 20 minutes to form a composite filler with an average particle size ≤8μm; add 2% stearic acid by mass of the composite filler as a dispersing aid to prevent agglomeration. d. Mix modified quartz sand and composite filler in a 7:3 ratio, add 18 parts silica sol (40% solid content) and an appropriate amount of deionized water, stir until the mixture has suitable fluidity, and the viscosity at Forte 4 cup is 70s, to form an outer slurry with a solid content ≥75%; 5. Mold preparation: Stainless steel molds are used, and the inner wall of the mold is coated with a release agent, such as silicone oil, to facilitate the demolding of the crucible products; 6. Layer-by-layer molding: The inner layer slurry, transition layer powder, reinforcing layer preform, and outer layer slurry are sequentially added into the mold to form the crucible blank. 7. Gradient drying: Place the formed crucible blank into a drying oven for gradient drying. First, dry at 70℃ for 3 hours to remove surface moisture; then dry at 120℃ for 5 hours to allow the moisture inside the blank to evaporate completely. 8. Segmented sintering: The dried crucible blank is placed in a high-temperature sintering furnace for segmented sintering: First, it is heated to 700℃ at a heating rate of 7℃ / min and held for 1.5 hours to remove organic matter and binder from the blank; then, it is heated to 1650℃ at a heating rate of 11℃ / min and held for 4 hours to fully sinter and fuse the materials of each layer; finally, it is cooled to room temperature with the furnace. 9. Demolding and Cleaning: Remove the sintered crucible product from the mold, perform surface trimming, and remove burrs and uneven parts from the edges; then perform ultrasonic cleaning to remove impurities and residues from the surface; finally, conduct quality inspection on the crucible product to ensure that the product meets the requirements.

[0034] Example 3 A method for preparing a corrosion-resistant and high-temperature-resistant composite quartz crucible includes the following steps: 1. Preparation of the inner layer slurry, including the following steps: a. Add 10 parts nano ZrO2, 5 parts B4C, and 4 parts SiC to deionized water at a solid-liquid ratio of 1:3, and disperse using an ultrasonic disperser (1000W power) for 40 minutes to form a uniform pre-dispersed slurry with a particle size ≤100nm. b. Add 85 parts of high-purity quartz sand to a planetary ball mill, pour in the pre-dispersed slurry prepared in step a, 12 parts of silica sol, and 3 parts of BaSiO3, and ball mill at 250 rpm for 6 hours. Use zirconia ball milling media and a ball-to-material ratio of 4:1 to ensure that the dispersion uniformity of each component is ≥98%. c. The mixture is transferred to a 45℃ constant temperature aging kettle and left to stand for 16 hours to promote the full hydrolysis and condensation of silica sol, forming a thixotropic paste-like inner layer slurry with a viscosity of 8000 mPa•s. 2. Preparation of transition layer powder, including the following steps: a. Add 80 parts of quartz sand, 15 parts of H3BO3, 8 parts of Al2O3, and 5 parts of BaB2O4 to a high-speed mixer, mix at 2000 rpm for 30 minutes until the particle size D90 ≤ 100 μm and the composition uniformity deviation < 2%; b. Add 5% (by weight of powder) of polyvinyl alcohol aqueous solution as a granulating agent, and dry it in a spray dryer with an inlet air temperature of 150℃ to produce 0.8mm spherical granules. c. Pre-calcine the spherical particles prepared in step b in a muffle furnace at 850°C for 2 hours to allow boric acid to initially soften and coat the quartz particles. d. After cooling the pre-burned particles in step c, spray the surface with 0.5wt% silane coupling agent KH-560 ethanol solution and dry at room temperature for 2 hours to form a micron-level interfacial active layer, reducing the contact angle by 40° to obtain the transition layer powder. 3. Prepare the reinforcing layer preform, including the following steps: a. Immerse the quartz fiber cloth in a 5wt% KH-550 ethanol solution (ethanol:water (mass ratio) = 8:2) for 20 minutes, and dry it at 130℃ for 40 minutes to graft silane coupling agent onto the fiber surface, increasing the surface hydroxyl density by 3 times, thus obtaining activated fiber cloth. b. Impregnation and Lamination: The activated fiber cloth is passed through an impregnation tank. The viscosity of the silicone resin adhesive in the impregnation tank is 500 mPa•s, and the adhesive application rate is controlled at 90 g / m. 2 The material is dried in an infrared drying oven at 80°C for 5 minutes to remove the solvent and reach a semi-cured state; then 5 layers are stacked in a 0° / 90° cross pattern to form a reinforcing layer preform. c. Hot pressing and curing: The preform is placed in a hot press and cured at 160℃ and 2.0MPa pressure for 5 hours. The curing process is divided into three stages: 50℃ for 1 hour, 100℃ for 1 hour, and 160℃ for 1 hour, forming a preform with a 0.6mm thick reinforcing layer and a fiber volume fraction ≥60%. 4. Preparation of the outer layer slurry, including the following steps: a. Add 80 parts of quartz sand to 5 parts of KH-570 ethanol solution (concentration 3%) and treat in a constant temperature stirred tank at 65℃ for 2.5 hours to graft silane coupling agent onto the surface of the quartz sand. b. Dry at 110℃ until the moisture content is <0.3% to form an active surface, increasing the surface energy by 25%; c. Prepare composite filler: Add 10 parts carbon powder, 8 parts BN, and 8 parts BP to a high-speed disperser and disperse at 2500 rpm for 20 minutes to form a composite filler with an average particle size ≤8μm; add 2% stearic acid by mass of the composite filler as a dispersing aid to prevent agglomeration. d. Mix modified quartz sand and composite filler in a 7:3 ratio, add 20 parts silica sol (40% solid content) and an appropriate amount of deionized water, stir until the mixture has suitable fluidity, and the viscosity at Forecast 4 cup is 80s, to form an outer slurry with a solid content ≥75%; 5. Mold preparation: Stainless steel molds are used, and the inner wall of the mold is coated with a release agent, such as silicone oil, to facilitate the demolding of the crucible products; 6. Layer-by-layer molding: The inner layer slurry, transition layer powder, reinforcing layer preform, and outer layer slurry are sequentially added into the mold to form the crucible blank. 7. Gradient drying: Place the formed crucible blank into a drying oven for gradient drying. First, dry at 80℃ for 2 hours to remove surface moisture; then dry at 150℃ for 4 hours to allow the moisture inside the blank to evaporate completely. 8. Segmented sintering: The dried crucible blank is placed in a high-temperature sintering furnace for segmented sintering: First, it is heated to 800℃ at a heating rate of 10℃ / min and held for 1 hour to remove organic matter and binder from the blank; then it is heated to 1700℃ at a heating rate of 15℃ / min and held for 3 hours to fully sinter and fuse the materials of each layer; finally, it is cooled to room temperature with the furnace. 9. Demolding and Cleaning: Remove the sintered crucible product from the mold, perform surface trimming, and remove burrs and uneven parts from the edges; then perform ultrasonic cleaning to remove impurities and residues from the surface; finally, conduct quality inspection on the crucible product to ensure that the product meets the requirements.

[0035] Comparative Example 1 The difference between this comparative example and Example 2 is that step 1 is omitted, and the inner layer slurry is not added in step 6. The remaining steps are the same as in Example 2.

[0036] Comparative Example 2 The difference between this comparative example and Example 2 is that step 2 is omitted, and the transition layer powder is not added in step 6. The remaining steps are the same as in Example 2.

[0037] Comparative Example 3 The difference between this comparative example and Example 2 is that step 3 is omitted, and the reinforcing layer prefabricated component is not added in step 6. The remaining steps are the same as in Example 2.

[0038] Comparative Example 4 The difference between this comparative example and Example 2 is that step 4 is omitted, and the outer layer slurry is not added in step 6. The remaining steps are the same as in Example 2.

[0039] Comparative Example 5 Traditional quartz crucibles, without any special treatment.

[0040] Experimental example: Table 1 shows the performance test results of the composite quartz crucibles prepared in Examples 1-3, the composite quartz crucibles prepared in Comparative Examples 1-4, and the conventional quartz crucible in Comparative Example 5.

[0041] Table 1 Performance test results of the composite quartz crucibles prepared in Examples 1-3, the composite quartz crucibles prepared in Comparative Examples 1-4, and the conventional quartz crucible in Comparative Example 5.

Claims

1. A corrosion-resistant and high-temperature-resistant composite quartz crucible, characterized in that, The laminate consists of the following weight parts from the inside out: inner layer 50-100 parts, transition layer 200-400 parts, reinforcing layer 150-250 parts, and outer layer 40-80 parts.

2. The corrosion-resistant and high-temperature-resistant composite quartz crucible according to claim 1, characterized in that, It should include at least one of the following technical features: (1) The raw materials of the inner layer include the following components by weight: 5-10 parts nano ZrO2, 3-5 parts B4C, 2-4 parts SiC, 80-85 parts high-purity quartz sand, 8-12 parts silica sol, and 1-3 parts BaSiO3. (2) The raw materials of the transition layer include the following components by weight: 75-80 parts of quartz sand, 10-15 parts of H3BO3, 5-8 parts of Al2O3, and 3-5 parts of BaB2O4; (3) The reinforcing layer is a quartz fiber cloth that has been impregnated with resin and then laminated; (4) The raw materials of the outer layer include the following components by weight: 70-80 parts of quartz sand, 30-34.3 parts of composite filler, and 15-20 parts of silica sol; the composite filler includes the following components by weight: 5-10 parts of carbon powder, 5-8 parts of BN, and 5-8 parts of BP.

3. A method for preparing a corrosion-resistant and high-temperature resistant composite quartz crucible, characterized in that, Includes the following steps: Step S1: Layer-by-layer molding. The inner layer slurry, transition layer powder, reinforcing layer preform, and outer layer slurry are sequentially added into the mold to form a crucible blank. Step S2, Gradient Drying: Place the formed crucible blank into a drying oven for gradient drying; Step S3, Segmented sintering: The dried crucible blank is placed in a high-temperature sintering furnace for segmented sintering. Finally, it is cooled to room temperature with the furnace and demolded to obtain the crucible product.

4. The method for preparing the corrosion-resistant and high-temperature resistant composite quartz crucible according to claim 3, characterized in that, The layer-by-layer forming method in step S1 is as follows: Step S1.1: First, pour the inner layer slurry into the mold and vibrate it to form the shape; Step S1.2: Evenly spread the transition layer powder on the inner surface, with a thickness of 2~3mm, and gently compact it; Step S1.3: Cover the reinforcing layer preform onto the transition layer powder, ensuring close adhesion between the preform and the transition layer powder; Step S1.4: Pour the outer layer slurry into the mold, cover it on the reinforcing layer preform, and vibrate it again to form the mold.

5. The method for preparing the corrosion-resistant and high-temperature-resistant composite quartz crucible according to claim 3, characterized in that, The preparation method of the inner layer slurry includes the following steps: a. Add 5-10 parts of nano ZrO2, 3-5 parts of B4C, and 2-4 parts of SiC to deionized water and ultrasonically disperse to form a uniform pre-dispersed slurry with a particle size ≤100nm. b. Add 80-85 parts of high-purity quartz sand to a planetary ball mill, pour in the pre-dispersed slurry prepared in step a, and 8-12 parts of silica sol and 1-3 parts of BaSiO3. Ball mill to make the dispersion uniformity of each component ≥98%. c. The mixture is transferred to a constant temperature aging kettle and left to stand, forming a thixotropic paste-like inner layer slurry with a viscosity of 5000~8000 mPa•s.

6. The method for preparing the corrosion-resistant and high-temperature-resistant composite quartz crucible according to claim 3, characterized in that, The method for preparing the transition layer powder includes the following steps: a. Add 75-80 parts of quartz sand, 10-15 parts of H3BO3, 5-8 parts of Al2O3, and 3-5 parts of BaB2O4 to a high-speed mixer and mix until the particle size D90 ≤ 100 μm and the composition uniformity deviation < 2%; b. Add granulating agent and spray dry to form spherical particles of 0.3~0.8mm; c. Pre-calcine the spherical particles prepared in step b in a muffle furnace to allow boric acid to initially soften and coat the quartz particles. d. After cooling the pre-burned particles from step c, spray the surface with KH-560 ethanol solution and dry at room temperature to form a micron-level interfacial active layer, thus obtaining the transition layer powder.

7. The method for preparing the corrosion-resistant and high-temperature-resistant composite quartz crucible according to claim 3, characterized in that, The method for preparing the reinforcing layer preform includes the following steps: a. Immerse and dry the quartz fiber cloth in KH-550 ethanol solution to graft silane coupling agent onto the fiber surface. b. Impregnation and Lamination: The activated fiber cloth is passed through an impregnation tank. The viscosity of the silicone resin adhesive in the impregnation tank is 300~500 mPa•s, and the adhesive application rate is controlled at 90~110 g / m. 2 The solvent is removed in an infrared drying oven until it reaches a semi-cured state; 3 to 5 layers are stacked in a 0° / 90° cross pattern to form a reinforcing layer preform. c. Hot pressing and curing molding: The blank is placed in a hot press and hot-pressed for 5 hours. The curing process is carried out by raising the temperature in stages and then keeping it at a constant temperature to form a preform with a reinforcing layer thickness of 0.4~0.6mm and a fiber volume fraction of ≥60%.

8. The method for preparing the corrosion-resistant and high-temperature-resistant composite quartz crucible according to claim 3, characterized in that, The method for preparing the outer layer slurry includes the following steps: a. Add 70-80 parts of quartz sand to KH-570 ethanol solution and stir at a constant temperature to graft silane coupling agent onto the surface of the quartz sand. b. Dry until the moisture content is <0.3% to form an active surface; c. Prepare composite filler: Add 5-10 parts carbon powder, 5-8 parts BN, and 5-8 parts BP to a high-speed disperser to form a composite filler with an average particle size ≤8μm; add stearic acid at 2% of the mass of the composite filler as a dispersing aid. d. Mix modified quartz sand and composite filler in a 7:3 ratio, add 15-20 parts silica sol and deionized water, and stir until the viscosity of the Forecast 4 cup is 60-80s to form an outer slurry with a solid content ≥75%.

9. The method for preparing the corrosion-resistant and high-temperature-resistant composite quartz crucible according to claim 3, characterized in that, The gradient drying method in step S2 is as follows: first, dry at 50~80℃ for 2~4 hours to remove surface moisture; then dry at 100~150℃ for 4~6 hours to allow the moisture in the blank to fully evaporate.

10. The method for preparing the corrosion-resistant and high-temperature-resistant composite quartz crucible according to claim 3, characterized in that, In step S3, the segmented sintering adopts gradient sintering. The gradient sintering method is as follows: first, heat to 600-800℃ at a heating rate of 5-10℃ / min and hold for 1-2 hours to remove organic matter and binder from the green body; then heat to 1600-1700℃ at a heating rate of 10-15℃ / min and hold for 3-5 hours.

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