Dome glass for space station and preparation method of dome glass

Abstract

The invention discloses dome glass for a space station and a preparation method of the dome glass, and relates to the technical field of glass preparation, the dome glass for the space station comprises the following oxides in percentage by mass: 70-80% of SiO2, 6-12% of B2O3, 3-8% of Al2O3, 2-5% of K2O, 0.5-2% of SrO, 0.4-1% of ZrO2, 0.05-0.2% of TiO2, 0.1-0.4% of La2O3 and 2-4% of Y2O3. The preparation method comprises the following steps: uniformly mixing the raw materials, melting and clarifying, pouring molten glass into a semispherical mold, carrying out ball-pressing molding to obtain semispherical glass with a certain thickness, annealing, grinding and polishing to obtain the semispherical dome glass meeting the requirements, wherein the melting temperature is 1600-1700 DEG C, the melting and clarifying time is 4-6 hours, the hydraulic punching force of a ball press is 1-5 tons, the heating temperature of the mold during ball pressing is 650-800 DEG C, and the temperature of the semispherical dome glass is 150-200 DEG C; the annealing temperature is 650-750 DEG C, and fine grinding is performed firstly and then accurate grinding is performed in the polishing process. The prepared dome glass material for the space station can keep high visible light transmittance in a space environment, has excellent thermal shock resistance and chemical stability, and provides a key material support for major aerospace engineering in China.

Description

Technical Field

[0001] This invention relates to the field of glass manufacturing technology, specifically to a dome glass for a space station and its manufacturing method. Background Technology

[0002] With the rapid development of space technology, the performance requirements for structural materials in space stations, as important bases for human exploration of the universe, are becoming increasingly stringent. The dome glass dome, as a key component of the space station, requires excellent light transmittance, radiation resistance, and thermal shock resistance to cope with the various challenges of the space environment. However, the fabrication of large-sized dome glass domes still faces many technical challenges.

[0003] To meet the operational environment of the space station, dome glass is generally hemispherical, possessing excellent thermal stability, mechanical properties, and optical protection. Quartz glass is the most common aerospace material, but its manufacturing conditions are demanding, production costs are high, its radiation protection is poor, and it is difficult to process into a hemispherical dome. These problems significantly limit the application of quartz glass. Summary of the Invention

[0004] The purpose of this invention is to provide a dome glass for space stations and its preparation method. By adjusting the glass composition and process, this invention prepares a hemispherical dome glass cover with excellent thermal stability, chemical stability, mechanical properties and optical protection properties, providing key material support for major aerospace projects.

[0005] The objective of this invention can be achieved through the following technical solutions: A dome glass for a space station, comprising the following oxide composition and mass percentages: SiO2: 70–80%, B2O3: 6–12%, Al2O3: 3–8%, K2O: 2–5%, SrO: 0.5–2%, ZrO2: 0.4%–1%, TiO2: 0.05–0.2%, La2O3: 0.1–0.4%, Y2O3: 2–4%.

[0006] As a further aspect of the present invention: the composition and mass percentage of the glass oxides used in the dome of the space station are as follows: SiO2: 72-80%, B2O3: 8-12%, Al2O3: 4-7%, K2O: 3-4%, SrO: 0.5-2%, ZrO2: 0.4%-1%, TiO2: 0.05-0.2%, La2O3: 0.1-0.4%, Y2O3: 2-3%.

[0007] As a further aspect of the present invention: the raw material of B2O3 is a mixture of B2O3 and H3BO3, and the mass ratio of B2O3 to H3BO3 is 1 to 3.

[0008] As a further aspect of the present invention: the raw material for K2O is a mixture of K2CO3 and KNO3, and the mass ratio of K2CO3 to KNO3 is 1 to 3.

[0009] As a further aspect of the present invention: the raw material for SrO is a mixture of SrCO3 and Sr(NO3)2, and the mass ratio of SrCO3 to Sr(NO3)2 is 2 to 5.

[0010] As a further aspect of the present invention: the coefficient of thermal expansion of the dome glass is 3.0 × 10⁻⁶. -6 / ℃~3.5×10 -6 / ℃, thermal shock resistance ΔT / ℃ ≥200, transmittance in the 450~780nm wavelength range ≥92%.

[0011] A method for preparing dome glass for a space station includes the following steps: mixing raw materials evenly and melting and clarifying them; pouring the molten glass into a hemispherical mold; pressing the glass into a hemispherical mold to obtain a hemispherical glass of a certain thickness; and then annealing and polishing to obtain the hemispherical dome glass.

[0012] As a further aspect of the present invention: the melting temperature is 1600℃~1700℃, the melting and clarifying time is 4h~6h, the hydraulic pressing pressure of the ball press is 1~5 tons, the mold heating temperature during ball pressing is 650~800℃, and the annealing temperature is 650℃~750℃.

[0013] As a further aspect of the present invention: the polishing process first uses diamond abrasive of different particle sizes to finely grind the inner and outer surfaces of the glass, and then uses polishing airbags of different radii to finely grind and polish the inner and outer surfaces of the dome glass.

[0014] The beneficial effects of this invention are: Suitable for use in the aerospace field, this glass possesses excellent thermal stability and mechanical properties; the coefficient of thermal expansion for the dome glass is 3.0 × 10⁻⁶. -6 / ℃~3.5×10 -6 With a thermal shock resistance of ΔT / ℃ ≥200 and a transmittance of ≥92% in the 450~780nm wavelength range, it exhibits excellent adaptability and protection against the environment during aerospace service, especially the space station environment. This application does not contain arsenic or antimony, and the provided preparation method has advantages such as simple preparation process, low production cost, and environmental friendliness. Attached Figure Description

[0015] The invention will now be further described with reference to the accompanying drawings.

[0016] Figure 1 This is a schematic diagram of the process of the present invention; Figure 2 This is a schematic diagram of the preparation equipment of the present invention. Detailed Implementation

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0018] A dome glass for a space station comprises the following raw materials in the indicated mass percentages: SiO2: 70-80%, B2O3: 6-12%, Al2O3: 3-8%, K2O: 2-5%, SrO: 0.5-2%, ZrO2: 0.4%-1%, TiO2: 0.05-0.2%, La2O3: 0.1-0.4%, Y2O3: 2-4%; In this embodiment, SiO2, as a glass network forger, is the main component constituting the glass network skeleton, effectively reducing the coefficient of thermal expansion of the glass and improving its thermal shock resistance, heat resistance, and mechanical strength. Controlling the SiO2 content range is beneficial to the thermal stability and mechanical strength of the glass in this application. Therefore, the SiO2 content is preferably 72-80%.

[0019] In this embodiment, B2O3 plays a unique role in glass, acting as a forming oxide to independently generate glass. It improves various glass properties and also possesses excellent fluxing properties, making it a good fluxing agent. When B2O3 is added to silicate glass, K2O provides free oxygen, which forms boron-oxygen tetrahedra [BO4] with boron. Since boron-oxygen tetrahedra have a framework structure, they can form a uniform glass structure with the silicon-oxygen tetrahedra [SiO4] in the glass structure, enhancing the glass's network structure. However, when the amount of boron added exceeds a certain limit, it appears in the glass structure not as boron-oxygen tetrahedra but as boron-oxygen trigonal bodies, causing the boron structure to transform from a framework structure to a layered structure, reducing the glass's network connectivity. Therefore, adjusting the B2O3 content helps reduce the viscosity of the molten glass, improves the glass's structural density, and results in a glass with good clarification and high mechanical strength. Therefore, the preferred B2O3 content is 8-12%.

[0020] In this embodiment, K2O is the network oxide of the glass, K +K₂O resides within the cavities of the glass structure network. It provides free oxygen, increasing the O / Si ratio in the glass structure and causing bond breakage, thus reducing the viscosity of the glass and making it easier to melt; it acts as a glass flux. However, excessive K₂O content reduces the chemical stability, thermal stability, and mechanical strength of the glass. The coefficient of thermal expansion and thermal shock resistance of the dome glass for the space station claimed in this invention are determined by the connectivity of the silicate subnetwork. To better balance these properties and obtain a glass material with superior overall performance, the K₂O content is preferably 3–4%.

[0021] In this embodiment, Al2O3 is an intermediate oxide. The addition of Al2O3 combines with free oxygen in the glass structure to form [AlO4], making the glass network structure more compact and improving its performance in various aspects. Therefore, the preferred Al2O3 content is 4–7%.

[0022] In this embodiment, SrO is an extracellular oxide in the glass network. SrO can improve the glass's ability to absorb radiation and its chemical stability to a certain extent. Therefore, the SrO content is 0.5%–2%.

[0023] In this embodiment, ZrO2 can significantly improve the chemical and thermal stability of glass, but its content should not be too high. Glass containing ZrO2 is prone to crystallization and difficult to melt. By adjusting the ZrO2 content within the range of this application, it is beneficial to reduce the thermal expansion coefficient of the glass and improve its thermal shock resistance. Therefore, the ZrO2 content is 0.4% to 1%.

[0024] In this embodiment, TiO2 can improve the refractive index and chemical stability of the glass, and adding an appropriate amount can improve the glass's ability to shield against radiation. However, TiO2-containing glass is prone to devitrification at low temperatures, so the TiO2 content is adjusted within the scope of this application, and the TiO2 content is 0.05% to 0.2%.

[0025] In this embodiment, La2O3 can effectively improve the chemical stability and radiation protection properties of the glass. Simultaneously, the oxygen produced by its thermal decomposition at high temperatures helps clarify the glass. However, excessive La2O3 content can also reduce the glass's stability. Therefore, the La2O3 content is 0.1–0.4%.

[0026] In this embodiment, the introduction of Y₂O₃ can form stronger chemical bonds with other oxides (such as SiO₂ and B₂O₃) in the glass network structure, making the glass structure denser, reducing its brittleness, increasing its toughness, and reducing the risk of breakage due to external impact. Simultaneously, Y₂O₃ has a certain shielding effect against some rays, giving the glass a certain degree of radiation protection, and it can also improve the chemical stability of the glass, making it more resistant to corrosion by acids, alkalis, and other chemical media. Therefore, the preferred Y₂O₃ content is 2–3%.

[0027] See Figure 1-2 As shown, the present invention also provides a method for preparing the glass material described above. It includes: mixing raw materials evenly and melting and clarifying them; pouring the molten glass into a hemispherical mold; pressing the glass into a hemispherical mold to obtain a hemispherical glass of a certain thickness; and then annealing and polishing it to obtain a hemispherical dome glass that meets the requirements. The melting temperature is 1600℃~1700℃ and the melting and clarifying time is 4h~6h.

[0028] This application relates to the preparation of hemispherical dome glass. In terms of forming, molten glass is poured into a special mold and pressed into a hemispherical shape. The hydraulic pressing pressure of the ball press is 1 to 5 tons. The mold is heated to 650 to 800°C during ball pressing. The annealing temperature of the glass after forming is 650°C to 750°C, preferably 700°C to 750°C.

[0029] This application relates to the preparation of hemispherical dome glass for aerospace applications. After pressing and molding, the glass needs to be ground and polished. The process involves first using diamond abrasive of different particle sizes to finely grind the inner and outer surfaces of the glass, and then using polishing airbags of different radii to finely grind and polish the inner and outer surfaces of the dome glass.

[0030] The dome glass provided in this application for use in space stations and other applications possesses excellent thermal stability, mechanical properties, and certain radiation protection capabilities. It can be used for observation windows, fairings, and component protective covers in spacecraft or space stations. This application does not impose any particular limitations on its application; selection can be made according to actual needs. Specific Implementation The present invention provides glass performance indicators for Examples 1-6 and Comparative Examples 1-5 as shown in Table 1. The raw materials for SiO2, B2O3, Al2O3, K2O, SrO, ZrO2, TiO2, La2O3, and Y2O3 are SiO2, B2O3+H3BO3, Al2O3, K2CO3+KNO3, SrCO3+Sr(NO3)2, ZrO2, TiO2, La2O3, and Y2O3, respectively. The above raw materials were stirred and mixed evenly, then placed in a furnace for high-temperature melting. The furnace temperature was raised to 1680℃ and held for 5 hours. After melting, the mixture was poured into a hemispherical mold for ball pressing. The ball press used a hydraulic pressing pressure of 2 tons, and the mold spray gun was heated to 700℃ during ball pressing. The ball was pressed into a hemispherical dome glass cover with a diameter of 1m. The dome glass cover was then placed in an annealing furnace at a temperature of 700℃. After annealing, the inner and outer surfaces of the glass were finely ground with diamond abrasive of different particle sizes, and then the inner and outer surfaces of the dome glass were finely polished using polishing airbags of different radii. The resulting dome glass for the space station was obtained.

[0032] Table 1: Weight percentage ratio of raw materials in Examples 1-6 As shown in Tables 1 (Examples 1-6), within the scope of the application components, the coefficient of thermal expansion of the dome glass for space stations provided by this invention is 3.0 × 10⁻⁶. -6 / ℃~3.5×10 -6 With a thermal shock resistance ΔT / ℃ ≥200 and a transmittance of ≥92% in the 450~780nm wavelength range, the dome glass for space stations and its preparation method provided by this invention not only have excellent thermal shock resistance but also high transmittance of visible light.

[0033] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A dome glass for a space station, characterized in that, The composition and mass percentage of the glass oxides used in the dome of the space station are as follows: SiO2: 70-80%, B2O3: 6-12%, Al2O3: 3-8%, K2O: 2-5%, SrO: 0.5-2%, ZrO2: 0.4%-1%, TiO2: 0.05-0.2%, La2O3: 0.1-0.4%, Y2O3: 2-4%.

2. The dome glass for a space station according to claim 1, characterized in that, The composition and mass percentage of the glass oxides used in the dome of the space station are as follows: SiO2: 72-80%, B2O3: 8-12%, Al2O3: 4-7%, K2O: 3-4%, SrO: 0.5-2%, ZrO2: 0.4%-1%, TiO2: 0.05-0.2%, La2O3: 0.1-0.4%, Y2O3: 2-3%.

3. The dome glass for a space station according to claim 1, characterized in that, The raw material for B2O3 is a mixture of B2O3 and H3BO3, with a mass ratio of B2O3 to H3BO3 of 1 to 3.

4. The dome glass for a space station according to claim 1, characterized in that, The raw material for K2O is a mixture of K2CO3 and KNO3, with a mass ratio of K2CO3 to KNO3 of 1 to 3.

5. A dome glass for a space station according to claim 1, characterized in that, The raw material for SrO is a mixture of SrCO3 and Sr(NO3)2, with a mass ratio of SrCO3 to Sr(NO3)2 of 2 to 5.

6. A dome glass for a space station according to claim 1, characterized in that, The coefficient of thermal expansion of the dome glass is 3.0 × 10⁻⁶. -6 / ℃~3.5×10 -6 / ℃, thermal shock resistance ΔT / ℃ ≥200, transmittance in the 450~780nm wavelength range ≥92%.

7. A method for preparing a space station dome glass according to any one of claims 1-5, characterized in that, Includes the following steps: The raw materials are mixed evenly and then melted and clarified. The molten glass is poured into a hemispherical mold and spherically pressed to obtain a hemispherical glass of a certain thickness. After annealing and polishing, a hemispherical dome glass is obtained.

8. A method for preparing a dome glass for a space station according to claim 7, characterized in that, The melting temperature is 1600℃~1700℃, the melting and clarifying time is 4h~6h, the hydraulic pressing pressure of the ball press is 1~5 tons, the mold heating temperature during ball pressing is 650~800℃, and the annealing temperature is 650℃~750℃.

9. A method for preparing a dome glass for a space station according to claim 7, characterized in that, The polishing process first uses diamond abrasive of different particle sizes to finely grind the inner and outer surfaces of the glass, and then uses polishing airbags of different radii to finely grind and polish the inner and outer surfaces of the dome glass.

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