High-temperature-resistant and corrosion-resistant quartz boat and preparation process thereof

Abstract

The invention discloses a high-temperature-resistant and corrosion-resistant quartz boat and a preparation process, and relates to the field of glass manufacturing, the quartz boat comprises a base material and a surface protection layer, the base material comprises the following components by mass: 100 parts of quartz sand; 0.5 to 1.2 parts of rare earth oxide; 0.4-1.3 parts of a crystal phase stabilizer, wherein the crystal phase stabilizer comprises 0.3-0.8 part of aluminum oxide and 0.1-0.5 part of zirconium oxide; 0.08 to 0.2 part of a reinforcing phase; the surface protection layer is a non-metal nitride film, and the thickness of the surface protection layer is 50-200 nm. By accurately regulating and controlling doping materials of the inner layer and the outer layer, utilizing gradient doping of ZrO2 of the inner layer and Al2O3 of the outer layer and combining the grain boundary stabilizing effect of rare earth oxide, the problems of high-temperature crystallization and high corrosion rate of a traditional quartz boat are solved, the ZrO2 of the inner layer inhibits lattice distortion by utilizing phase change energy absorption and oxygen vacancy regulation and control, the Al2O3 of the outer layer forms a compact passivation layer to block corrosion medium permeation, and the corrosion rate of the quartz boat is improved. The structure of the quartz boat is kept stable in high-temperature, corrosion and violent temperature change environments, so that the high-temperature stability and corrosion resistance under extreme conditions are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of glass manufacturing, and particularly to a method for producing quartz, specifically a high-temperature resistant and corrosion-resistant quartz boat and its preparation process. Background Art

[0002] A quartz boat, that is, quartz glass, as a key load-bearing component in high-temperature and corrosive environments, is widely used in semiconductor manufacturing, photovoltaic material processing, etc., and needs to work stably in high-temperature and strong corrosive environments for a long time. Traditional quartz boats are mainly composed of high-purity silica (SiO2), which has excellent thermal stability (softening point about 1730 °C) and chemical inertness (almost does not react with other acids except hydrofluoric acid), and can maintain a stable physical form in high-temperature environments. Its long-term use temperature can reach 1100 °C, and it can even withstand a high temperature of up to 1450 °C for a short time.

[0003] However, with the increasing demand for extreme condition tolerance in industrial application scenarios, there are still significant technical defects in existing quartz boats under extreme conditions. In high-temperature environments, conventional quartz materials exhibit crystallization embrittlement due to the instability of the lattice structure. When the temperature exceeds 1500 °C, the crystallization rate significantly increases to more than 8%, resulting in a sharp deterioration of the mechanical properties of the material and even posing a risk of fracture. At the same time, in strong acid environments (such as 40% hydrofluoric acid), the corrosion rate of traditional quartz boats is as high as 0.15 - 0.3 mm / h, and the surface protective layer is easily damaged, leading to a significant reduction in service life and making it difficult to meet the requirements of advanced processes for device reuse.

[0004] Therefore, it is necessary to improve the deficiencies in the existing technology to solve the above problems. Summary of the Invention

[0005] The present invention overcomes the deficiencies of the existing technology and provides a high-temperature resistant and corrosion-resistant quartz boat and its preparation process. By precisely regulating the synergistic effect of rare earth oxides and gradient crystal phase stabilizers, combined with the three-dimensional network strengthening effect of nano-enhanced phases, the limitations of high-temperature crystallization and high corrosion rate of traditional quartz boats are successfully overcome, providing strong support for the quartz boat in more extensive and harsher industrial applications.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a high-temperature resistant and corrosion-resistant quartz boat, comprising a matrix material and a surface protective layer. The matrix material comprises the following components in parts by mass: Quartz sand 100 parts; Rare earth oxide 0.5 - 1.2 parts; Crystal phase stabilizer 0.4 - 1.3 parts, including 0.3 - 0.8 parts of alumina and 0.1 - 0.5 parts of zirconia; Enhanced phase 0.08 - 0.2 parts; The surface protective layer is a non-metallic nitride film with a thickness of 50-200 nm.

[0007] In a preferred embodiment of the present invention, the rare earth oxide is one of yttrium oxide or lanthanum oxide; the particle size of the zirconia is 30-80 nm.

[0008] In a preferred embodiment of the present invention, the reinforcing phase is silicon carbide nanowires with a diameter of 20-50 nm and an aspect ratio of 40-60.

[0009] In a preferred embodiment of the present invention, the non-metallic nitride film is a silicon nitride film formed by plasma chemical vapor deposition, and the surface roughness Ra≤0.1 μm.

[0010] The present invention provides a preparation process for a high-temperature resistant and corrosion-resistant quartz boat, comprising the following steps: S1. Pickle quartz sand with a mixed acid solution at 60-90 °C for 1-3 h. After pickling and drying, divide it into inner-layer quartz sand and outer-layer quartz sand according to a mass ratio of 6:4-8:2. S2. Ball-mill and disperse the inner-layer quartz sand, rare earth oxide, zirconia and reinforcing phase in a ball mill to form an inner-layer mixture, and ball-mill and disperse the outer-layer quartz sand and alumina in a ball mill to form an outer-layer mixture. S3. Use a two-channel hot-pressing die. Fill the inner-layer mixture into the central cavity and the outer-layer mixture into the annular cavity. Pre-sinter at a temperature of 1100-1300 °C, and then main-sinter at a temperature of 1400-1500 °C, and cool and form to obtain a preliminary quartz boat. S4. Form a non-metallic nitride film on the surface of the preliminary quartz boat by plasma chemical vapor deposition to obtain a high-temperature resistant and corrosion-resistant quartz boat.

[0011] In a preferred embodiment of the present invention, in the S1 step, the mixed acid solution is a mixed solution of hydrofluoric acid and nitric acid with a volume ratio of 1:1-3.

[0012] In a preferred embodiment of the present invention, in the S2 step, the ball-milling and dispersion specifically are: using ethanol as a medium, ball-milling and dispersing at a rotation speed of 200-400 rpm for 3-4 h.

[0013] In a preferred embodiment of the present invention, in the S3 step, the parameters of the pre-sintering are: pressure 3-8 MPa, time 20-40 min, vacuum degree 1×10 -2 Pa; the parameters of the main-sintering are: pressure 10-20 MPa, time 50-60 min, vacuum degree 5×10 -3 Pa.

[0014] In a preferred embodiment of the present invention, in the step S3, the heating rate of the pre-sintering is 10-15 °C / min, and the heating rate of the main sintering is 5-8 °C / min.

[0015] In a preferred embodiment of the present invention, in the step S4, the parameters of the plasma chemical vapor deposition are as follows: the reaction gases are silane and ammonia with a flow ratio of 1:3-5, the deposition temperature is 390-420 °C, the chamber pressure is 30-70 Pa, the radio frequency power is 400-600 W, and the deposition rate is 1.5-2.5 nm / min.

[0016] The present invention solves the defects existing in the background technology, and the present invention has the following beneficial effects: (1) The present invention provides a high-temperature resistant and corrosion-resistant quartz boat and its preparation process. By precisely controlling the inner and outer layer doping materials, using the gradient doping of ZrO2 in the inner layer and Al2O3 in the outer layer, combined with the grain boundary stabilizing effect of rare earth oxides, the problems of high-temperature crystallization and high corrosion rate of traditional quartz boats are solved. The inner layer ZrO2 uses phase change energy absorption and oxygen vacancy regulation to inhibit lattice distortion, and the outer layer Al2O3 forms a dense passivation layer to block the penetration of corrosive media. At the same time, the thermal expansion difference realizes the gradual release of thermal stress through gradient distribution, so that the quartz boat maintains structural stability under high temperature, corrosion and severe temperature change environments, thereby ensuring high-temperature stability and corrosion resistance under extreme conditions.

[0017] (2) In the present invention, by introducing a three-dimensional network reinforcement phase of SiC nanowires, synergistically bonding the interfaces of the matrix and the crystal phase stabilizer, the problems of uneven stress dispersion, weak interface bonding and local overheating of traditional reinforcement materials are solved. The SiC nanowires disperse thermal stress through a high-strength covalent bond framework, and the surface oxide layer on its surface forms a chemical bond with the matrix to strengthen the interface. At the same time, the high thermal conductivity equalizes the heat distribution, thereby significantly improving the thermal shock resistance, high-temperature resistance and corrosion resistance comprehensive performance of the quartz boat.

[0018] (3) In the present invention, through the silicon nitride protective layer formed by surface treatment, the Si3N4 thin film tightly covers the surface of the quartz matrix through a dense network structure of Si-N covalent bonds. Its high bond energy characteristics effectively block the diffusion of oxygen ions and high-temperature oxidation erosion. The Si-O-N gradient bonding interface formed between the surface of the thin film and the matrix relieves the interface stress caused by thermal expansion difference through chemical bond bridging. In an acidic environment, the continuous dense structure of the thin film hinders the penetration path of corrosive molecules such as hydrofluoric acid, and the low roughness further reduces the local corrosion initiation points caused by defects. At the same time, the stable crystal lattice of Si3N4 inhibits atomic migration at high temperature and maintains the integrity of the protective layer, thereby further realizing the performance of high-temperature resistance and corrosion resistance. Detailed implementation mode

[0019] The described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts belong to the scope of protection of the present invention.

[0020] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited by the specific embodiments disclosed below.

[0021] It should be noted that the raw materials, equipment, reagents, etc. used in the present invention can all be obtained through market purchase or by means of preparation in the prior art.

[0022] A high-temperature and corrosion-resistant quartz boat includes a matrix material and a surface protective layer. The matrix material includes the following components in parts by mass: Quartz sand: 100 parts; Rare earth oxide: 0.5 - 1.2 parts; Crystal phase stabilizer: 0.4 - 1.3 parts, including 0.3 - 0.8 parts of alumina (Al2O3) and 0.1 - 0.5 parts of zirconia (ZrO2); Reinforcing phase: 0.08 - 0.2 parts; The surface protective layer is a non-metallic nitride film with a thickness of 50 - 200 nm.

[0023] In some specific embodiments, the rare earth oxide is one of yttrium oxide (Y2O3) or lanthanum oxide (La2O3); the particle size of zirconia is 30 - 80 nm.

[0024] In some specific embodiments, the reinforcing phase is silicon carbide (SiC) nanowires with a diameter of 20 - 50 nm and an aspect ratio of 40 - 60.

[0025] In some specific embodiments, the non-metallic nitride film is a silicon nitride (Si3N4) film formed by plasma chemical vapor deposition, and the surface roughness Ra ≤ 0.1 μm.

[0026] The present invention provides a preparation process for a high-temperature and corrosion-resistant quartz boat, including the following steps: S1. Pickle quartz sand with a mixed acid solution at 60 - 90 °C for 1 - 3 h. After pickling and drying, divide it into inner-layer quartz sand and outer-layer quartz sand according to a mass ratio of 6:4 - 8:2; S2. Ball-mill and disperse the inner-layer quartz sand, rare earth oxide, zirconia, and reinforcing phase in a ball mill to form an inner-layer mixture, and ball-mill and disperse the outer-layer quartz sand and alumina in a ball mill to form an outer-layer mixture; S3. Adopt a double-channel hot-pressing die. The inner-layer mixture is filled into the central cavity, and the outer-layer mixture is filled into the annular cavity. Pre-sinter at a temperature of 1100 - 1300 °C, and then perform main sintering at a temperature of 1400 - 1500 °C, and cool and form to obtain a preliminary quartz boat. S4. Form a non-metallic nitride film on the surface of the preliminary quartz boat through plasma chemical vapor deposition to obtain a high-temperature and corrosion-resistant quartz boat.

[0027] It should be noted that the double-channel hot-pressing die refers to a hot-pressing die with two independent channels. The two channels can be used to convey different materials or the same material respectively, and after converging in the die, they are formed and processed. The specific structure is a general standard part or a component known to those skilled in the art, and will not be elaborated in detail here.

[0028] In some specific embodiments, in step S1, the mixed acid solution is a mixed solution of hydrofluoric acid (40% HF solution) and nitric acid (HNO3) with a volume ratio of 1:1 - 3.

[0029] In some specific embodiments, in step S2, the ball milling and dispersion are specifically as follows: using ethanol as the medium, ball milling and dispersing at a rotation speed of 200 - 400 rpm for 3 - 4 h.

[0030] In some specific embodiments, in step S3, the parameters of the pre-sintering are: pressure 3 - 8 MPa, time 20 - 40 min, vacuum degree 1×10 -2 Pa; the parameters of the main sintering are: pressure 10 - 20 MPa, time 50 - 60 min, vacuum degree 5×10 -3 Pa.

[0031] In some specific embodiments, in step S3, the heating rate of the pre-sintering is 10 - 15 °C / min, and the heating rate of the main sintering is 5 - 8 °C / min.

[0032] In some specific embodiments, in step S4, the parameters of the plasma chemical vapor deposition are: the reaction gases are silane (SiH4) and ammonia (NH3) with a flow ratio of 1:3 - 5, the deposition temperature is 390 - 420 °C, the chamber pressure is 30 - 70 Pa, the radio frequency power is 400 - 600 W, and the deposition rate is 1.5 - 2.5 nm / min.

[0033] It should be noted that by adopting PACVD, compared with traditional CVD (requiring >800 °C), PACVD can form a film at a temperature of about 400 °C, avoiding crystallization of the quartz boat body.

[0034] To further make the object and effect of the present invention simple and easy to understand, the present invention is further elaborated in combination with examples and comparative examples.

[0035] It should be noted that in the examples and comparative examples, the preparation raw materials are described as follows: Quartz sand: purity of SiO2 ≥ 99.9%, particle size of 100 mesh, density of 1.7 g / cm³, purchased from Can Chen Mine in Shijiazhuang; Y2O3: purity ≥ 99.9%, purchased from Shandong Mengxi New Materials; La2O3: purity ≥ 99.9%, purchased from Shandong Mengxi New Materials; Al2O3: purity ≥ 99.9%, purchased from Shandong Mengxi New Materials; ZrO2: purity ≥ 99.9%, particle diameter of 30 nm, purchased from Hebei Yuehan Metal Materials; SiC nanowires: purity ≥ 99.9%, CAS number 409 - 21 - 2, diameter of 30 nm, aspect ratio of 52, purchased from Shandong Xinbaiyi Metals; Si3N4: purity ≥ 99.95%, CAS number 12033 - 89 - 5, purchased from Jiuxin New Materials in Nangong City.

[0036] The raw materials of the high - temperature - resistant and corrosion - resistant quartz boat matrix materials in Examples 1 - 9, as well as the different raw material ratios, are specifically shown in Table 1, and the material consumption of the raw materials is measured in parts by mass.

[0037] Table 1: Preparation raw materials and ratios of high - temperature - resistant and corrosion - resistant quartz boat matrix materials in Examples 1 - 9

[0038] Example 1

[0039] A preparation process of a high - temperature - resistant and corrosion - resistant quartz boat includes the following steps: S1. Immerse the quartz sand in a mixed solution of hydrofluoric acid (40% HF solution) and HNO3 with a volume ratio of 1:2, and pickle it at 80 °C for 2 h. After the pickled quartz sand is washed with water until neutral, it is vacuum - dried at 105 °C for 2 h, and is divided into inner - layer quartz sand and outer - layer quartz sand according to a mass ratio of 7:3; S2. Put the inner - layer quartz sand, Y2O3, ZrO2 and SiC nanowires into a ball mill, use ethanol as the medium, and ball - mill and disperse them at a rotation speed of 300 rpm for 4 h to form an inner - layer mixture. Put the outer - layer quartz sand and Al2O3 into a ball mill, use ethanol as the medium, and ball - mill and disperse them at a rotation speed of 300 rpm for 4 h to form an outer - layer mixture; S3. Use a double - channel hot - pressing die. The inner - layer mixture is filled into the central cavity, and the outer - layer mixture is filled into the annular cavity. At a heating rate of 13 °C / min, at a temperature of 1200 °C, a pressure of 5 MPa, and a vacuum degree of 1×10 -2 Pa, pre - sinter for 30 min, and at a heating rate of 7 °C / min, at a temperature of 1450 °C, a pressure of 15 MPa, and a vacuum degree of 5×10 -3 Pa, main - sinter for 60 min, and cool and form to obtain a preliminary quartz boat; S4. Through PACVD, using SiH4 and NH3 reaction gases with a flow ratio of 1:3, a deposition temperature of 400 °C, a chamber pressure of 50 Pa, a radio frequency power of 500 W, and a deposition rate of 2 nm / min, form a Si3N4 film with a thickness of 130 nm and a surface roughness Ra ≤ 0.1 μm on the surface of the initial quartz boat to obtain a high-temperature and corrosion-resistant quartz boat.

[0040] Example 2

[0041] This example is basically the same as Example 1, the difference is: the raw material ratio is different, as shown in Table 1; the specific steps of S1 are: put the quartz sand in a mixed solution of hydrofluoric acid (40% HF solution) and HNO3 with a volume ratio of 1:2, pickling at 80 °C for 2 h. After the pickled quartz sand is rinsed with water until neutral, vacuum dry at 105 °C for 2 h, and divide it into inner-layer quartz sand and outer-layer quartz sand according to a mass ratio of 6:4.

[0042] Example 3

[0043] This example is basically the same as Example 1, the difference is: the raw materials and their ratios are different, as shown in Table 1; the specific steps of S1 are: put the quartz sand in a mixed solution of hydrofluoric acid (40% HF solution) and HNO3 with a volume ratio of 1:2, pickling at 80 °C for 2 h. After the pickled quartz sand is rinsed with water until neutral, vacuum dry at 105 °C for 2 h, and divide it into inner-layer quartz sand and outer-layer quartz sand according to a mass ratio of 8:2.

[0044] Example 4

[0045] This example is basically the same as Example 1, the difference is: the raw materials and their ratios are different, as shown in Table 1; the specific steps of S3 are: use a double-channel hot pressing mold, fill the inner-layer mixture into the central cavity and the outer-layer mixture into the annular cavity. At a heating rate of 13 °C / min, at a temperature of 1100 °C, a pressure of 5 MPa, and a vacuum degree of 1×10 -2 Pa, pre-sinter for 30 min, and at a heating rate of 7 °C / min, at a temperature of 1450 °C, a pressure of 15 MPa, and a vacuum degree of 5×10 -3 Pa, main sinter for 60 min, and cool and form to obtain the initial quartz boat.

[0046] Example 5

[0047] This example is basically the same as Example 1, the difference is: the raw materials and their ratios are different, as shown in Table 1; the specific steps of S3 are: use a double-channel hot pressing mold, fill the inner-layer mixture into the central cavity and the outer-layer mixture into the annular cavity. At a heating rate of 13 °C / min, at a temperature of 1300 °C, a pressure of 5 MPa, and a vacuum degree of 1×10 -2Under a vacuum degree of Pa, pre-sinter for 30 min, and at a heating rate of 7 °C / min, at a temperature of 1450 °C, a pressure of 15 MPa, 5×10 -3 Under a vacuum degree of Pa, main-sinter for 60 min, cool and form to obtain a preliminary quartz boat.

[0048] Example 6

[0049] This example is basically the same as Example 1, the difference is that: the raw materials and their ratios are different, as shown in Table 1; the specific steps of S3 are: adopt a double-channel hot pressing die, fill the inner layer mixture into the central cavity, and fill the outer layer mixture into the annular cavity. At a heating rate of 13 °C / min, at a temperature of 1200 °C, a pressure of 5 MPa, 1×10 -2 Under a vacuum degree of Pa, pre-sinter for 30 min, and at a heating rate of 7 °C / min, at a temperature of 1400 °C, a pressure of 15 MPa, 5×10 -3 Under a vacuum degree of Pa, main-sinter for 60 min, cool and form to obtain a preliminary quartz boat.

[0050] Example 7

[0051] This example is basically the same as Example 1, the difference is that: the raw material ratio is different, as shown in Table 1; the specific steps of S3 are: adopt a double-channel hot pressing die, fill the inner layer mixture into the central cavity, and fill the outer layer mixture into the annular cavity. At a heating rate of 13 °C / min, at a temperature of 1200 °C, a pressure of 5 MPa, 1×10 -2 Under a vacuum degree of Pa, pre-sinter for 30 min, and at a heating rate of 7 °C / min, at a temperature of 1500 °C, a pressure of 15 MPa, 5×10 -3 Under a vacuum degree of Pa, main-sinter for 60 min, cool and form to obtain a preliminary quartz boat.

[0052] Example 8

[0053] This example is basically the same as Example 1, the difference is that: the raw material ratio is different, as shown in Table 1; the specific steps of S4 are: through PACVD, use SiH4 and NH3 reaction gases with a flow ratio of 1:3, a deposition temperature of 400 °C, a chamber pressure of 50 Pa, a radio frequency power of 500 W, a deposition rate of 2 nm / min, and form a Si3N4 film with a thickness of 50 nm and a surface roughness Ra≤0.1 μm on the surface of the preliminary quartz boat to obtain a high-temperature and corrosion-resistant quartz boat.

[0054] Example 9

[0055] This embodiment is basically the same as Embodiment 1, except that: the raw material ratio is different, as shown in Table 1; the steps of S4 are specifically as follows: by PACVD, using the reaction gases of SiH4 and NH3 with a flow ratio of 1:3, a deposition temperature of 400 °C, a chamber pressure of 50 Pa, a radio frequency power of 500 W, and a deposition rate of 2 nm / min, a Si3N4 film with a thickness of 200 nm and a surface roughness Ra≤0.1 μm is formed on the surface of the initial quartz boat to obtain a high-temperature resistant and corrosion-resistant quartz boat.

[0056] Performance testing: The quartz boats obtained in the above Embodiments 1-9 were made into specimens of 50 mm×10 mm×10 mm, and the performance tests of high-temperature resistance and corrosion resistance were carried out successively, and the results are shown in Table 2.

[0057] High-temperature resistance test (1): The specimens were placed in a high-temperature furnace at 1500 °C and continuously heated for 100 h, and their crystallization rate (XRD analysis) and bending strength retention rate (three-point bending method) were measured.

[0058] High-temperature resistance test (2): The specimens were quickly immersed in normal-temperature water from a high temperature of 1200 °C, and the surface cracks were observed after 10 cycles.

[0059] Corrosion resistance test (1): The specimens were immersed in 40% hydrofluoric acid (25 °C) for 24 h, and the corrosion rate was calculated by the weight loss method.

[0060] Corrosion resistance test (2): The specimens were exposed in a chlorine gas atmosphere at 800 °C for 100 h, and the surface roughness change rate was measured by a surface profilometer.

[0061] Table 2: Performance test results of the quartz boats obtained in Embodiments 1-9

[0062] As shown in Table 2: Through the comparison of Embodiments 1-9, it can be known that: through gradient doping, the construction of a three-dimensional network of nano-reinforcing phases, and the optimization of chemical bonding of the surface protective layer, the present invention solves the defects of high-temperature crystallization, high corrosion rate, and insufficient thermal shock resistance of traditional quartz boats. The obtained quartz boats show excellent high-temperature resistance and stability, and at the same time show excellent corrosion resistance.

[0063] Specifically, ZrO2 is used as the inner layer doping material and Al2O3 is used as the outer layer doping material. The high-temperature phase change behavior of ZrO2 forms a dynamic coupling with the Si-O bonds in the SiO2 network through oxygen vacancies, inhibiting the crystallization tendency of quartz glass. At the same time, rare earth oxides (Y2O3 / La2O3) combine with ZrO2 to form a composite structure, stabilizing the grain boundaries and compensating for charge imbalance, enhancing the high-temperature structural stability of the material; Al2O3 forms Al 3It reacts with SiO2 to form a dense aluminosilicate glass phase, reducing the surface defect density. Its strong Al-O bond forms a gradient transition layer with the Si-O bond, effectively buffering thermal stress. Meanwhile, in a corrosive environment, Al2O3 will preferentially react to form a colloidal passivation film, which crosslinks with the hydroxyl groups on the surface of SiO2 to form an anti-permeation barrier. The difference in thermal expansion coefficients between ZrO2 and Al2O3 realizes the gradual release of thermal stress through gradient distribution. Furthermore, the oxygen diffusion blocking effect on the surface layer of Al2O3 and the oxygen vacancies in the inner layer of ZrO2 form a directional migration channel, jointly inhibiting the aggregation of lattice defects. Rare earth elements further form a transition layer at the interface, reducing interface defects through ion pinning and charge balance, and finally optimizing the overall high-temperature resistance, thermal shock resistance, and corrosion resistance of the material.

[0064] Furthermore, through the further synergy of the reinforcing phases, the Si-C covalent bond (bond energy 435 kJ / mol) of SiC nanowires has higher thermal stability than the Si-O bond (452 kJ / mol) in SiO2 at high temperatures. By forming a three-dimensional network skeleton in the SiO2 matrix, the reinforcing phases can effectively disperse thermal stress and inhibit the propagation of microcracks. At the same time, SiC nanowires and ZrO2 particles form local stress buffer units through Si-O-Zr bonding at the interface at high temperatures, synergistically enhancing the thermal shock resistance with the energy absorption effect of the phase transformation of ZrO2. Moreover, the aluminosilicate glass phase generated on the surface layer of Al2O3 bonds with the Si-O-Al on the surface of SiC to form a continuous and dense passivation layer, hindering the penetration of corrosive media. Furthermore, the high thermal conductivity of SiC nanowires promotes the rapid conduction of heat along the axial direction, reducing the lattice distortion caused by local overheating. Thus, the high-temperature resistance and corrosion resistance of the quartz boat are synergistically enhanced through a multi-level interfacial bonding and thermal-mechanical synergy mechanism.

[0065] Comparative Example 1 Commercially available: Quartz boat, silicon content 99.99%, grade: XZ-SYZ812, purchased from Shandong Longmei Industrial and Mining.

[0066] Comparative Example 2 This comparative example is basically the same as Example 1, except that: Al2O3 is not added to the outer layer mixture. The steps of S2 are as follows: The inner layer quartz sand, Y2O3, ZrO2, and SiC nanowires are ball-milled and dispersed in a ball mill with ethanol as the medium at a rotation speed of 300 rpm for 4 h to form an inner layer mixture. The outer layer quartz sand is ball-milled and dispersed in a ball mill with ethanol as the medium at a rotation speed of 300 rpm for 4 h to form an outer layer mixture.

[0067] Comparative Example 3 This comparative example is basically the same as Example 1, except that: ZrO2 is not added to the inner-layer mixture. The steps of S2 are as follows: The inner-layer quartz sand, Y2O3, and SiC nanowires are ball-milled and dispersed in a ball mill with ethanol as the medium at a rotation speed of 300 rpm for 4 h to form the inner-layer mixture. The outer-layer quartz sand and Al2O3 are ball-milled and dispersed in a ball mill with ethanol as the medium at a rotation speed of 300 rpm for 4 h to form the outer-layer mixture.

[0068] Comparative Example 4 This comparative example is basically the same as Example 1, except that: The distribution of the crystal phase stabilizer in the inner and outer layer mixtures is different. The steps of S2 are as follows: The inner-layer quartz sand, Y2O3, Al2O3, and SiC nanowires are ball-milled and dispersed in a ball mill with ethanol as the medium at a rotation speed of 300 rpm for 4 h to form the inner-layer mixture. The outer-layer quartz sand and ZrO2 are ball-milled and dispersed in a ball mill with ethanol as the medium at a rotation speed of 300 rpm for 4 h to form the outer-layer mixture.

[0069] Comparative Example 5 This comparative example is basically the same as Example 1, except that: It is not formed by layered gradient molding. A preparation process of a high-temperature resistant and corrosion-resistant quartz boat includes the following steps: S1. The quartz sand is pickled in a mixed solution of hydrofluoric acid (40% HF solution) and HNO3 with a volume ratio of 1:2 at 80 °C for 2 h. After the pickled quartz sand is washed with water until neutral, it is vacuum-dried at 105 °C for 2 h to obtain the quartz sand base material. S2. The quartz sand base material, Y2O3, ZrO2, Al2O3, and SiC nanowires are ball-milled and dispersed in a ball mill with ethanol as the medium at a rotation speed of 300 rpm for 4 h to form a mixture. S3. The mixture is pre-sintered at a heating rate of 13 °C / min at a temperature of 1200 °C, a pressure of 5 MPa, and a vacuum degree of 1×10 -2 Pa for 30 min, and then main-sintered at a heating rate of 7 °C / min at a temperature of 1450 °C, a pressure of 15 MPa, and a vacuum degree of 5×10 -3 Pa for 60 min, and then cooled and formed to obtain the initial quartz boat. S4. By PACVD, using the reaction gases of SiH4 and NH3 with a flow ratio of 1:3, a deposition temperature of 400 °C, a chamber pressure of 50 Pa, a radio frequency power of 500 W, and a deposition rate of 2 nm / min, a Si3N4 film with a thickness of 130 nm and a surface roughness Ra≤0.1 μm is formed on the surface of the initial quartz boat to obtain the high-temperature resistant and corrosion-resistant quartz boat.

[0070] Comparative Example 6 This comparative example is basically the same as Example 1, except that the amount of Al2O3 is different. Specifically, in terms of parts by mass, Al2O3 is 0.9 parts.

[0071] Comparative Example 7 This comparative example is basically the same as Example 1, except that the amount of Al2O3 is different. Specifically, in terms of parts by mass, Al2O3 is 0.2 parts.

[0072] Comparative Example 8 This comparative example is basically the same as Example 1, except that the amount of ZrO2 is different. Specifically, in terms of parts by mass, ZrO2 is 0.6 parts.

[0073] Comparative Example 9 This comparative example is basically the same as Example 1, except that the amount of ZrO2 is different. Specifically, in terms of parts by mass, ZrO2 is 0.05 parts.

[0074] Comparative Example 10 This comparative example is basically the same as Example 1, except that no reinforcing phase is added. The steps of S2 are as follows: Inner layer quartz sand, Y2O3 and ZrO2 are ball-milled and dispersed in a ball mill with ethanol as the medium at a rotation speed of 300 rpm for 4 h to form an inner layer mixture. Outer layer quartz sand and Al2O3 are ball-milled and dispersed in a ball mill with ethanol as the medium at a rotation speed of 300 rpm for 4 h to form an outer layer mixture.

[0075] Comparative Example 11 This comparative example is basically the same as Example 1, except that the addition position of the reinforcing phase is different. The steps of S2 are as follows: Inner layer quartz sand, Y2O3 and ZrO2 are ball-milled and dispersed in a ball mill with ethanol as the medium at a rotation speed of 300 rpm for 4 h to form an inner layer mixture. Outer layer quartz sand, Al2O3 and SiC nanowires are ball-milled and dispersed in a ball mill with ethanol as the medium at a rotation speed of 300 rpm for 4 h to form an outer layer mixture.

[0076] Comparative Example 12 This comparative example is basically the same as Example 1, except that the amount of SiC nanowires is different. Specifically, in terms of parts by mass, SiC nanowires are 0.3 parts.

[0077] Comparative Example 13 This comparative example is basically the same as Example 1, except that the amount of SiC nanowires is different. Specifically, in terms of parts by mass, SiC nanowires are 0.05 parts.

[0078] Comparative Example 14 This comparative example is basically the same as Example 1, except that: without surface treatment, a preparation process of a high-temperature resistant and corrosion-resistant quartz boat includes the following steps: S1. Put quartz sand into a mixed solution of hydrofluoric acid (40% HF solution) and HNO3 with a volume ratio of 1:2, and pickle it at 80 °C for 2 h. After the pickled quartz sand is rinsed with water until neutral, it is vacuum dried at 105 °C for 2 h, and is divided into inner-layer quartz sand and outer-layer quartz sand according to a mass ratio of 7:3; S2. Put the inner-layer quartz sand, Y2O3, ZrO2 and SiC nanowires into a ball mill, use ethanol as the medium, and ball mill and disperse them at a rotation speed of 300 rpm for 4 h to form an inner-layer mixture. Put the outer-layer quartz sand and Al2O3 into a ball mill, use ethanol as the medium, and ball mill and disperse them at a rotation speed of 300 rpm for 4 h to form an outer-layer mixture; S3. Use a double-channel hot pressing die, fill the inner-layer mixture into the central cavity, fill the outer-layer mixture into the annular cavity, and pre-sinter at a heating rate of 13 °C / min, at a temperature of 1200 °C, a pressure of 5 MPa, and a vacuum degree of 1×10 -2 Pa for 30 min, and then sinter at a heating rate of 7 °C / min, at a temperature of 1450 °C, a pressure of 15 MPa, and a vacuum degree of 5×10 -3 Pa for 60 min, and cool and form to obtain a quartz boat.

[0079] Comparative Example 15 This comparative example is basically the same as Example 1, except that: without staged sintering, the steps of S3 are specifically: use a double-channel hot pressing die, fill the inner-layer mixture into the central cavity, fill the outer-layer mixture into the annular cavity, and sinter at a heating rate of 7 °C / min, at a temperature of 1450 °C, a pressure of 15 MPa, and a vacuum degree of 5×10 -3 Pa for 90 min, and cool and form to obtain a preliminary quartz boat.

[0080] Performance detection: Make the commercially available quartz boat of Comparative Example 1 and the quartz boats obtained in Comparative Examples 2-15 into specimens of 50 mm×10 mm×10 mm, and use the same performance test method as the quartz boats obtained in Examples 1-9 to conduct high-temperature resistance and corrosion resistance performance tests in sequence, and the results are shown in Table 3.

[0081] Table 3: Performance test results of the quartz boats obtained in Comparative Examples 1-15

[0082] As shown in Table 3: It can be known from the comparison between Examples 1-9 and Comparative Example 1 that: in the traditional quartz boat, gradient doping and nano-enhanced phase are not introduced. In its pure SiO2 matrix, due to the disordered aggregation of oxygen vacancies at high temperature, the grain boundary migration is accelerated (the crystallization rate is as high as 10.64%), and there is a lack of Al2O3 passivation layer and Si3N4 protective layer. The surface Si-OH groups are directly exposed to the corrosive medium, resulting in the hydrofluoric acid corrosion rate (0.28 mm / h) far exceeding that of the examples of the present invention (0.03 mm / h).

[0083] It can be known from the comparison between Examples 1-9 and Comparative Examples 2-3 that: the absence of Al2O3 in Comparative Example 2 results in the inability to form aluminosilicate glass phase in the outer layer, and the corrosive medium directly erodes the matrix (the corrosion rate rises to 0.16 mm / h); the absence of inner layer ZrO2 in Comparative Example 3 causes the loss of grain boundary pinning effect, the crystallization rate increases to 8.18%, and the lack of energy absorption effect of ZrO2 phase transformation leads to the propagation of thermal shock cracks (the crack length is 123 μm).

[0084] It can be known from the comparison between Examples 1-9 and Comparative Example 4 that: adding Al2O3 to the inner layer and ZrO2 to the outer layer destroys the gradient thermal expansion matching mechanism. The strong bonding between inner layer Al2O3 and SiO2 leads to too high rigidity to buffer stress through phase transformation, while the outer layer ZrO2 cannot stabilize oxygen vacancies due to the lack of rare earth coordination, and the interfacial stress concentration triggers thermal shock cracks (the crack length is 78 μm).

[0085] It can be known from the comparison between Examples 1-9 and Comparative Example 5 that: the unstratified mixed sintering leads to the failure of gradient doping, the disordered distribution of Al2O3 and ZrO2, and the inability to form a gradient transition interface and a directional thermal stress release channel. The energy absorption effect of ZrO2 phase transformation in the inner layer and the passivation effect of Al2O3 in the outer layer interfere with each other, and the crystallization rate (7.19%) and the bending strength retention rate (69.94%) are significantly inferior to those of the examples.

[0086] It can be known from the comparison between Examples 1-9 and Comparative Examples 6-7 that: excessive Al2O3 (Comparative Example 6) leads to an increase in surface brittleness, and the mismatch of thermal expansion coefficients causes microcracks (the crack length is 61 μm); insufficient Al2O3 (Comparative Example 7) results in an incomplete passivation layer, and the penetration of the corrosive medium is accelerated (the corrosion rate is 0.15 mm / h). Too high or too low dosage will damage the compactness of the Al-O-Si network.

[0087] It can be known from the comparison between Examples 1-9 and Comparative Examples 8-9 that: excessive ZrO2 (Comparative Example 8) causes insufficient Y 3 + concentration at the grain boundary, resulting in excessive aggregation of oxygen vacancies and a decrease in the resistance of grain boundary migration (the crystallization rate is 5.36%); insufficient ZrO2 (Comparative Example 9) has a weak energy absorption effect of phase transformation, and the thermal stress cannot be effectively released (the crack length is 88 μm).

[0088] It can be seen from the comparison between Examples 1-9 and Comparative Example 10 that the absence of SiC nanowires causes the matrix to lack a three-dimensional reinforcement network, thermal stress concentrates in local areas (crack length 112 μm), the flexural strength and thermal shock resistance are significantly reduced, the corrosion path is more likely to penetrate along the cracks, and the uneven heat distribution exacerbates lattice distortion (crystallization rate 6.85%).

[0089] It can be seen from the comparison between Examples 1-9 and Comparative Example 11 that when SiC nanowires are placed in the outer mixture, their interfacial bonding with Al2O3 is weaker than that with inner ZrO2, and effective bonding (such as Si-O-Al bonds) cannot be formed. The stress dispersion effect of the nanowires is limited (crack length 79 μm), and the outer nanowires hinder the continuity of the Al2O3 passivation layer.

[0090] It can be seen from the comparison between Examples 1-9 and Comparative Examples 12-13 that excessive nanowires (Comparative Example 12) hinder the densification of the matrix, and the interfacial porosity increases (corrosion rate 0.15 mm / h); insufficient nanowires (Comparative Example 13) result in weak strengthening effect, and the retention rate of flexural strength drops to 75.47%.

[0091] It can be seen from the comparison between Examples 1-9 and Comparative Example 14 that the absence of the Si3N4 film allows the SiO2 matrix to directly contact the corrosive medium. The Si-OH groups react with HF to form SiF4 (corrosion rate 0.23 mm / h), and at high temperatures, the diffusion of oxygen ions accelerates the deterioration of grain boundaries, and the corrosion rate and crystallization rate increase synchronously (crystallization rate 8.35%).

[0092] It can be seen from the comparison between Examples 1-9 and Comparative Example 15 that direct single-stage high-temperature sintering leads to asynchronous densification of the inner and outer layer materials, insufficient bonding of Si-O-Zr and Si-O-Al at the interface, an increase in grain boundary defects (crystallization rate 8.12%), and a significant decrease in thermal shock resistance (crack length 62 μm).

[0093] Based on the ideal embodiments of the present invention as an inspiration, through the above description, for those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, it is intended to encompass all changes falling within the meaning and scope of the equivalent elements of the claims in the present invention.

[0094] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only includes an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A preparation process of a high-temperature resistant and corrosion-resistant quartz boat, characterized in that, It includes the following steps: S1. Pickle quartz sand with a mixed acid solution at 60 - 90 °C for 1 - 3 h. After pickling and drying, divide it into inner-layer quartz sand and outer-layer quartz sand according to a mass ratio of 6:4 - 8:

2. S2. Ball-mill and disperse the inner-layer quartz sand, rare-earth oxide, zirconia, and reinforcing phase in a ball mill to form an inner-layer mixture, and ball-mill and disperse the outer-layer quartz sand and alumina in a ball mill to form an outer-layer mixture. S3. Use a double-channel hot-press die. Fill the central cavity with the inner-layer mixture and the annular cavity with the outer-layer mixture. Pre-sinter at a temperature of 1100 - 1300 °C and main-sinter at a temperature of 1400 - 1500 °C, then cool and form to obtain a preliminary quartz boat. S4. Form a non-metallic nitride film on the surface of the preliminary quartz boat through plasma chemical vapor deposition to obtain a high-temperature and corrosion-resistant quartz boat.

2. The preparation process of a high-temperature and corrosion-resistant quartz boat according to claim 1, characterized in that: In the step S1, the mixed acid solution is a mixed solution of hydrofluoric acid and nitric acid with a volume ratio of 1:1 - 3.

3. The preparation process of a high-temperature and corrosion-resistant quartz boat according to claim 1, characterized in that: In the step S2, the ball-milling and dispersion are specifically as follows: Using ethanol as the medium, ball-mill and disperse at a rotation speed of 200 - 400 rpm for 3 - 4 h.

4. The preparation process of a high-temperature and corrosion-resistant quartz boat according to claim 1, characterized in that: In the step S3, the parameters for pre-sintering are: pressure 3 - 8 MPa, time 20 - 40 min, vacuum degree 1×10 -2 Pa; the parameters for main sintering are: pressure 10 - 20 MPa, time 50 - 60 min, vacuum degree 5×10 -3 Pa.

5. The preparation process of a high-temperature and corrosion-resistant quartz boat according to claim 1, characterized in that: In the step S3, the heating rate of the pre-sintering is 10 - 15 °C / min, and the heating rate of the main-sintering is 5 - 8 °C / min.

6. The preparation process of a high-temperature and corrosion-resistant quartz boat according to claim 1, characterized in that: In the step S4, the parameters of the plasma chemical vapor deposition are: The reaction gases are silane and ammonia with a flow ratio of 1:3 - 5, the deposition temperature is 390 - 420 °C, the chamber pressure is 30 - 70 Pa, the radio frequency power is 400 - 600 W, and the deposition rate is 1.5 - 2.5 nm / min.

7. A high-temperature and corrosion-resistant quartz boat, characterized in that: Prepared by the preparation process according to any one of claims 1 - 6, the quartz boat includes a matrix material and a surface protective layer. The matrix material includes the following components in parts by mass: Quartz sand 100 parts; Rare-earth oxide 0.5 - 1.2 parts; Crystal phase stabilizer 0.4 - 1.3 parts, including 0.3 - 0.8 parts of alumina and 0.1 - 0.5 parts of zirconia; Reinforcing phase 0.08 - 0.2 parts; The surface protective layer is a non-metallic nitride film with a thickness of 50 - 200 nm.

8. A high-temperature and corrosion-resistant quartz boat according to claim 7, characterized in that: The rare-earth oxide is one of yttrium oxide or lanthanum oxide; the particle size of the zirconia is 30 - 80 nm.

9. The high-temperature and corrosion-resistant quartz boat according to claim 7, wherein: The reinforcing phase is silicon carbide nanowires with a diameter of 20 - 50 nm and an aspect ratio of 40 - 60.

10. A high-temperature and corrosion-resistant quartz boat according to claim 7, characterized in that: The non-metallic nitride film is a silicon nitride film generated by plasma chemical vapor deposition, and the surface roughness Ra ≤ 0.1 μm.

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