Cladding glass tube for gas melt pressure forming and preparation method and application thereof

Abstract

The invention discloses a cladded glass tube for gas melt pressure forming and a preparation method and application of the cladded glass tube. The cladding glass tube composition comprises the following components by mole percent: 70.0-80.0% of SiO2; 0.5 to 2.5 percent of Al2O3; 3.0 to 8.0% of B2O3; 0.1 to 1.0 percent of Li2O; 5.0 to 10.0 percent of Na2O (sodium oxide); 5.0% to 10.0% of K2O; 0.1 to 1.0 percent of MgO; 1.0 to 6.0 percent of CaO; 0.1 to 0.7 percent of TiO2; 0.01 to 0.3 percent of SnO2; and 0 to 0.04% of Y2O3. The cladding glass tube provided by the invention has the characteristics of environmental protection and no heavy metal oxide component, and is suitable for preparing a micro-channel plate with uniform internal structure, high gain, low noise and wide dynamic response.

Description

Technical Field

[0001] The present invention relates to the field of glass material manufacturing, and in particular to a cladding glass tube for gas melting and pressing, and a preparation method and application thereof. Background Art

[0002] The micro-channel plate (MCP) is an advanced thin-film electron multiplier device with the characteristics of high gain, low noise, high resolution, long life, and self-saturation effect. It is a key component of the second, third, and currently fourth-generation low-light level image intensifiers, photomultiplier tubes, camera tubes, and particle detection devices. Its noise is the main noise source of image intensifiers. Image intensifier noise leads to low yield of Chinese image intensifiers and short detection distance of image tubes in imaging systems, affecting the international competitiveness of China's micro-channel plate back-end products. Therefore, conducting research on new micro-channel plate preparation methods or optimizing micro-channel plate blank forming technology has practical guiding significance for the development of low-noise, high-gain micro-channel plates.

[0003] In the existing preparation process and material system of microchannel plates, the melt-pressing method of microchannel plate blanks is generally mechanical melt-pressing. When the microchannel plate fiber filaments are regularly arranged and tightly stacked, the fiber bundles are arranged into hexagonal microchannel plate screen segments, which are loaded into a metal mold. The mold is placed in a well-type hot pressing furnace. After heating, pressure is applied to the upper end of the mold, the slider shrinks, and the microchannel plate screen segments are thermally fused. However, this method of preparing microchannel slabs by mechanical hot pressing not only has low processing efficiency, but also uses complex auxiliary tools and tooling equipment, and raw materials and auxiliary materials such as mica sheets are severely consumed, the production cost is high, the production efficiency is low, and the production cycle is long. The prepared microchannel slabs will have serious fiber deformation in the six directions near the slider, and will cause the internal structure to have various performance indicators such as top corner holes, multifilament misalignment, structural top-to-bottom, resistance abnormality, etc., which are unqualified. These problems seriously affect the preparation of microchannel plates with uniform internal structure, high gain, low noise, and wide dynamic response, and limit the realization of high-definition and high-sensitivity image transmission functions of low-light night vision devices.

[0004] For a long time, the most commonly used MCP (Microchannel Plate) glass in various fields, such as low-light-level night vision, has been lead silicate glass. However, the complex manufacturing process for microchannel plates (MCPs) remains a challenge, and these challenges are becoming increasingly prominent as performance indicators improve. For example, internal structural unevenness can occur. During the blanking process, variations in fiber length can cause variations in channel diameter, resulting in uneven imaging in back-end equipment. Small-aperture MCPs are limited by molds during blanking, resulting in reduced spatial resolution in back-end equipment. Heavy metals, such as lead (Pb), are particularly problematic during raw material preparation, posing a significant environmental risk. As restrictions on toxic and hazardous components and their content in electronic devices become increasingly stringent in both Chinese and international markets, the import of lead-containing glass materials or products is strictly prohibited in Europe and the United States. China has also consistently advocated for green and circular production, prioritizing employee health and environmental protection.

[0005] After the microchannel plate blank is prepared by gas melting and pressing technology, the above-mentioned mechanical melting and pressing molds, mica sheets and other raw materials and auxiliary materials are no longer needed. The auxiliary materials and consumables of the gas melting and pressing technology are converted into glass tube sleeve materials for the microchannel plate screen plate segments, so very high requirements are placed on the glass tube sleeve materials. Summary of the Invention

[0006] The purpose of the present invention is to address the defects of the above-mentioned prior art and provide a cladding glass tube for gas melting and pressing and a preparation method thereof. The glass is environmentally friendly and has no heavy metal oxide components. It is suitable for preparing microchannel slabs with uniform internal structure, high gain, low noise and wide dynamic response.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] A cladding glass tube composition for gas melting and pressing, comprising the following components in molar percentages:

[0009]

[0010] The present invention also provides a preferred technical solution, a cladding glass tube composition for gas melting and pressing, preferably comprising the following components in molar percentage:

[0011]

[0012] The present invention also provides a more preferred technical solution, a cladding glass tube composition for gas melting and pressing, preferably comprising the following components in molar percentage:

[0013]

[0014] The present invention further provides a method for preparing a cladding glass tube for gas melting and pressing using the composition, comprising the following steps:

[0015] (1) Glass melting: Quartz sand, aluminum hydroxide, boric acid or boric anhydride, lithium carbonate, sodium carbonate, potassium carbonate or potassium nitrate, basic magnesium carbonate, calcium carbonate, titanium dioxide, tin oxide and yttrium oxide are weighed and mixed uniformly according to the ingredient requirements, and then placed in a glass melting furnace and melted at 1500-1600°C for 12-24 hours;

[0016] (2) Clarification and homogenization: After the raw materials are melted into glass melt, the glass melt flows from the glass melting pool into the stirring pool and is fully stirred, and then flows into the clarification pool at 1400-1480°C. The glass melt is clarified and homogenized for 4-6 hours to remove and absorb small bubbles, and then flows into the material basin to cool down;

[0017] (3) Tube drawing: After the glass liquid is cooled to 1200-1350°C, the glass liquid flows from the material basin to the feed channel and then to the forming nozzle. After passing through the forming nozzle, the glass liquid is pulled by the tube drawing machine to form a uniformly formed glass tube; the thickness of the glass tube is controlled at 2.5±1.5mm, and the inner diameter of the glass tube is controlled at Φ30.0±3.0mm;

[0018] (4) Cutting annealing: Cut the drawn glass tube into a certain length as required, and then place the cut glass tube in an annealing furnace at 560-600°C for annealing for 24-36 hours;

[0019] (5) Bottom sealing: The annealed glass tube is sealed with a flame for a flat bottom, and the tube mouth is singed with a flame to remove burrs. The length of the glass tube after the bottom sealing is 1.5 times to 2.5 times the length of the microchannel plate screen section; it can be compatible with the gas melting and pressing molding of the microchannel plate screen section; the microchannel plate screen section is a 12-sided structure, and the length of the microchannel plate screen section is 50-150 mm.

[0020] The present invention further provides a cladding glass tube for preparing a microchannel slab by gas melting and pressing, which is prepared according to the preparation method.

[0021] The present invention further provides the use of the cladding glass tube for placing microchannel screen segments in microchannel slab blanks produced by gas melt-pressing technology. The microchannel plates produced using the cladding glass tube are used in low-light-level image intensifiers. The bottom-sealed glass tube of the present invention is suitable for producing microchannel slab blanks.

[0022] In the cladding glass composition used for preparing microchannel slabs by gas-melting pressing, SiO2 forms the main component of the glass skeleton and plays a major role in the glass framework. The molar percentage of SiO2 is 70.0-80.0 mol%, preferably 74.0-79.0 mol%. A SiO2 content below 70.0 mol% makes it difficult to obtain glass with a suitable expansion coefficient and reduces the chemical stability of the glass. A SiO2 content above 80.0 mol% increases the high-temperature viscosity of the glass, resulting in excessively high glass melting temperatures and production costs, which is detrimental to glass production.

[0023] Al2O3 is an intermediate oxide of glass. 3+ Glass has two coordination states: tetrahedral and octahedral. When the glass contains sufficient oxygen, aluminum oxide tetrahedra (AlO4) form, forming a continuous network with silicon oxide tetrahedra. When the glass contains insufficient oxygen, aluminum oxide octahedra (AlO6) form, acting as network extraneous bodies within the cavities of the silicon oxide network. Therefore, within a certain content range, Al2O3 can serve as the primary network-forming component, similar to SiO2. The molar percentage of Al2O3 is 0.5-2.5 mol%, preferably 1.0-1.5 mol%. Al2O3 is the primary component regulating the strain point temperature of the glass, enabling the glass to withstand cold nitrogen injection at high temperatures without cracking or fracturing, and to withstand thermal shock. When the Al2O3 content is lower than 0.5 mol%, the brittleness of the glass will increase, and the strain point temperature of the glass will not be high enough, which is not conducive to the hot and cold shock of the glass tube, and will cause the glass tube sleeve material to explode during the gas melting and pressing process of preparing the microchannel plate blank; when the Al2O3 content is greater than 2.5 mol%, the melting temperature of the glass will be significantly increased, and the high-temperature viscosity of the glass will be significantly increased, which is not conducive to the high-temperature softening of the glass tube, so that the glass tube sleeve material and the microchannel plate screen section cannot achieve better hot pressing fusion.

[0024] B2O3 is a glass-forming oxide and a component of the glass skeleton. It is also a flux that reduces the viscosity of the glass. Boron oxide triangles [BO3] and boron oxide tetrahedrons [BO4] are structural components. Boron may exist in the form of triangles [BO3] or boron oxide tetrahedrons [BO4] under different conditions. Under high-temperature melting conditions, it is generally difficult to form boron oxide tetrahedrons and can only exist in the form of trihedrons. However, at low temperatures, under certain conditions, B 3+B2O3 tends to capture free oxygen to form tetrahedra, compacting the structure and increasing the low-temperature viscosity of the glass. However, due to its properties of decreasing glass viscosity at high temperatures and increasing it at low temperatures, and being the primary component that reduces the glass's refractive index, the B2O3 content range is relatively small. The molar percentage of B2O3 is 3.0-8.0 mol%, preferably 4.0-5.9 mol%. A B2O3 content below 3.0 mol% fails to act as a flux and reduces the chemical stability of the glass. A B2O3 content greater than 8.0 mol% lowers the strain point temperature of the glass and prolongs the glass frit, hindering mechanical drawing of the glass tube and increasing the tendency of the glass to separate phases.

[0025] Li2O is an alkali metal oxide and an external oxide of the glass structure network. The molar percentage of Li2O is 0.1-1.0 mol.%, preferably 0.2-0.5 mol.%, and mainly plays the role of reducing the viscosity of the molten glass. A Li2O content greater than 1.0 mol.% will increase the crystallization tendency of the glass.

[0026] Na2O is an alkali metal oxide and an external oxide of the glass structure network. The molar percentage of Na2O is 5.0-10.0 mol.%, preferably 5.5-8.0 mol.%. If the content of Na2O is less than 5.0 mol.%, it will not play a role in regulating the high-temperature melting viscosity of the glass. If the content of Na2O is greater than 10 mol.%, it will increase the thermal expansion coefficient of the glass and increase the crystallization tendency of the glass.

[0027] K2O is an alkali metal oxide and an external oxide of the glass structure network. The molar percentage of K2O is 5.0-10.0 mol%. Preferably, it is 5.5-7.0 mol%. If the content of K2O is less than 5.0 mol%, it will not play a role in regulating the high-temperature melting viscosity of the glass. If the content of K2O is greater than 10.0 mol%, it will increase the thermal expansion coefficient of the glass and increase the crystallization tendency of the glass.

[0028] MgO is an alkaline earth metal oxide and an external oxide of the glass structure network. The molar percentage of MgO is 0.1-1.0 mol.%, preferably 0.1-0.8 mol.%. MgO is an important component for adjusting the soft and hard strength of glass. It can prevent the glass tube from breaking after being heated and softened and then pressurized by gas injection. If the MgO content is greater than 1.0 mol.%, it will reduce the chemical stability of the glass and increase the tendency of the glass to crystallize.

[0029] CaO is an alkaline earth metal oxide and a network oxide of the glass structure. The molar percentage of CaO is 1.0-6.0 mol%, preferably 2.0-4.9 mol%. If the CaO content is greater than 6.0 mol%, it will reduce the chemical stability of the glass and increase the crystallization tendency of the glass.

[0030] TiO2 in the glass melt presents Ti 3+ and Ti 4+ There are two valence states, usually Ti in silicate glass 4+ The valence state exists, and its 3d orbital is empty, and the "dd" transition between electrons in the d orbital cannot occur, so Ti 4+ The valence state appears colorless in glass, however, due to the Ti 4+ It can strongly absorb ultraviolet rays, and its absorption band can usually enter the purple-blue part of the visible light region, causing the glass to actually appear brownish yellow, especially Ti 4+ It has the effect of enhancing the coloring of transition elements, so that even if the glass raw materials contain a small amount of transition elements, the resulting glass will still have a darker color. This effect is particularly obvious for iron. The molar percentage of TiO2 is 0.1-0.7mol.%, preferably 0.1-0.4mol.%. TiO2 is an important component for regulating the softening point temperature of glass, which can make the glass cladding material and the microchannel plate screen section better fit and melt-press molded. When the TiO2 content is less than 0.1mol.%, there will be a gap that cannot be eliminated when the cladding glass and the microchannel plate screen section are fused at high temperature, resulting in misalignment or distortion of the internal structure. When the TiO2 content is greater than 0.7mol.%, the gas-melting and pressing temperature of the microchannel plate will be increased, resulting in abnormal resistance performance of the microchannel plate.

[0031] SnO2 is a glass clarifier and an important component in regulating the sealing between the glass cladding material and the metal flange, improving the sealing performance between the glass and the metal flange. The molar percentage of SnO2 is 0.01-0.3 mol%, preferably 0.05-0.2 mol%. A SnO2 content greater than 0.3 mol% will reduce the sealing performance between the glass and the metal flange and increase the tendency of the glass to crystallize.

[0032] Y2O3 is used to adjust the high-temperature viscosity characteristics and softening temperature of glass. The molar percentage of Y2O3 is 0-0.04 mol%. A Y2O3 content greater than 0.04 mol% will increase the melting cost of the glass and increase the crystallization tendency of the glass.

[0033] The glass of the present invention is silicate glass, and does not contain oxides of heavy metal elements such as As2O3, Sb2O3, PbO, CdO, BaO, etc. Even if it contains extremely small amounts, they are introduced from other glass raw materials. However, when introducing the glass raw materials, the content of these variable valence elements must be strictly controlled below 1ppm.

[0034] Compared with the prior art, the cladding glass for preparing microchannel slabs by gas melting and pressing of the present invention has the following beneficial effects:

[0035] (1) The glass does not contain heavy metal oxides harmful to the environment such as As2O3, Sb2O3, PbO, CdO, BaO, etc., and is an environmentally friendly glass material;

[0036] (2) The glass has excellent chemical properties and stable glass composition, making it suitable for mechanical tube drawing and mass production;

[0037] (3) The average linear thermal expansion coefficient of the glass in the range of 30-300°C is (85±3)×10 -7 / ℃, the strain point temperature of the glass is greater than 520℃, and it can withstand the temperature difference impact of cold nitrogen during gas melt pressing without bursting;

[0038] (4) The glass has good compatibility with the MCP material and can meet the thermal expansion coefficient of (75±3)×10 -7 / ℃ gas melting pressing preparation requirements for microchannel plate materials, so that the microchannel plate screen plate segment does not explode after gas melting pressing;

[0039] (5) The glass does not crystallize or separate when kept at 850-900℃ for 6 hours, and has excellent anti-crystallization performance;

[0040] (6) The glass has good compatibility with the sealing glass and metal flange, and can meet the requirements of melting and bonding the glass tube, sealing glass and metal flange without cracking at high temperatures;

[0041] (7) The glass is suitable for preparing microchannel plate blanks by gas melting and pressing technology. The glass can realize the regulation of the resistance-temperature characteristics of the microchannel plate, slow down the trend of the body resistance increasing sharply with temperature during the preparation process of the microchannel plate blank, and obtain a microchannel plate with suitable body resistance and resistance-temperature characteristics.

[0042] The present invention also provides an application of cladding glass for preparing microchannel plate blanks by gas melting and pressing, which has an important impact on reducing the noise performance of microchannel plates and meeting the application requirements of high resolution and low resistance. The cladding glass for preparing microchannel plate blanks by gas melting and pressing of the present invention has the advantage of matching the microchannel plate blank material, thereby achieving uniform internal structure, high gain, low defects, and low noise preparation of the microchannel plate. The application of this cladding material in the gas melting and pressing technology can prevent abnormal resistance of the microchannel plate. Microchannel plates are usually used under room temperature conditions, and the conventional bulk resistance is 100-200MΩ. After the cladding glass of the microchannel plate blank is prepared by gas melting and pressing, a microchannel plate with suitable bulk resistance and resistance-temperature characteristics is obtained, which improves the ability of the microchannel plate to quickly read and respond to signals, and promotes the further application of the microchannel plate in fields such as micro-signal detection.

[0043] The microchannel plate prepared by the cladding glass used for gas melting and pressing of the present invention is used in low-light-level image intensifiers, which can effectively improve the imaging clarity, sensitivity and gain performance of the low-light-level image tube. The product can meet the supporting needs of the low-light-level night vision industry, and can also replace the traditional mechanical melting and pressing method to prepare microchannel plate products, improve the comprehensive performance, and promote the development of optoelectronic devices in related fields such as space vision measurement and detection imaging towards high energy and wide field of view, and has a good prospect for application and promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 Schematic diagram of preparing a microchannel slab by gas melt pressing according to an embodiment of the present invention;

[0045] Figure 2 This is a schematic diagram of the assembly of the glass tube sleeve and the microchannel plate screen plate segment provided in an embodiment of the present invention;

[0046] Figure 3 It is a cross-sectional schematic diagram of the assembly of the glass tube sleeve and the 12-sided microchannel plate screen plate segment provided by an embodiment of the present invention.

[0047] Among them, 101 is the furnace core of the gas melting and pressing furnace, 102 is the heating zone of the gas melting and pressing furnace, 103 is the microchannel plate screen plate section, 104 is the glass tube sleeve, 105 is a detachable metal flange with a quick-change connector, 106 is a vacuum metal tube, 107 is the air injection port, and 108 is the air release port. DETAILED DESCRIPTION

[0048] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0049] See also Figure 1 A heating zone 102 of the gas melting pressing furnace is provided on the periphery of the furnace 101 of the gas melting pressing furnace. A glass tube sleeve 104 made of cladding glass is provided in the furnace 101 of the gas melting pressing furnace. A microchannel plate screen plate segment 103 is placed in the glass tube sleeve 104. The glass tube sleeve 104 and the vacuum metal tube 106 are connected by a detachable metal flange 105 with a quick-change joint. The vacuum metal tube 106 extends out of the furnace 101 of the gas melting pressing furnace. The upper end opening of the furnace 101 of the gas melting pressing furnace is provided with an air injection port 107 and an air release port 108.

[0050] See also Figure 2 and Figure 3The microchannel plate screen segment 103 has a dodecagonal structure. The dodecagonal microchannel plate screen segment structure is closer to a circle than the conventional hexagonal screen segment. The thickness of the glass tube sleeve 104 is controlled at 2.5±1.5 mm, and the inner diameter of the glass tube sleeve 104 is controlled at Φ30.0±3.0 mm. The structural design of the microchannel plate screen segment and the thickness and inner diameter design of the glass tube sleeve of the present invention are more conducive to the hot pressing fusion of the glass tube sleeve 104 and the microchannel plate screen segment 103, and can also save the use of microchannel plate fiber filaments.

[0051] The parameters, test methods, and instruments used for the cladding glass tube prepared by gas melting and pressing of the present invention are as follows:

[0052] (1) Average linear thermal expansion coefficient α at 30-300℃ 30 / 300 Measured using a horizontal dilatometer, expressed as the average linear thermal expansion coefficient, using the method specified in GB / T 7962.16-2010 "Test methods for colorless optical glass - Part 16: Linear expansion coefficient, transition temperature and relaxation temperature";

[0053] (2) The strain point temperature is measured using the method specified in SJ / T 11039-1996 “Test Method for Annealing Point and Strain Point of Electronic Glass”;

[0054] (3) The softening point temperature shall be in accordance with GB / T 28195-2011 “Test method for softening point of glass”.

[0055] Table 1 Chemical composition (mol.%) and properties of cladding glass examples for gas melting and pressing

[0056] Composition (mol.%) Example 1 Example 2 Example 3 Example 4 Example 5 <![CDATA[SiO2]]> 77.20％ 78.63％ 77.38％ 75.70％ 74.60％ <![CDATA[Al2O3]]> 1.38％ 1.19％ 1.15％ 1.11％ 1.00％ <![CDATA[B2O3]]> 4.00％ 4.59％ 4.51％ 5.90％ 4.97％ <![CDATA[Li2O]]> 0.46％ 0.50％ 0.50％ 0.20％ 0.38％ <![CDATA[Na2O]]> 7.72％ 6.54％ 7.53％ 5.52％ 8.00％ <![CDATA[K2O]]> 5.68％ 5.52％ 5.56％ 6.96％ 5.59％ MgO 0.78％ 0.69％ 0.58％ 0.39％ 0.10％ CaO 2.24％ 2.06％ 2.36％ 3.72％ 4.90％ <![CDATA[TiO2]]> 0.34％ 0.12％ 0.31％ 0.38％ 0.39％ <![CDATA[SnO2]]> 0.19％ 0.15％ 0.10％ 0.11％ 0.05％ <![CDATA[Y2O3]]> 0.01％ 0.01％ 0.02％ 0.01％ 0.02％ <![CDATA[α 30 / 300 [10 -7 / ℃]]]> 85.1 83.4 84.5 85.3 87.8 Strain point temperature (℃) 521 544 538 522 528 Glass transition temperature 543 547 549 548 546 Expansion softening temperature (℃) 631 635 638 633 634 Softening point temperature (℃) 744 746 748 745 741

[0057] Example 1

[0058] Select raw materials according to the glass composition of Example 1 in Table 1 so that the ingredients meet the glass chemical composition of Table 1, and then prepare the cladding glass tube according to the following steps:

[0059] (1) Glass melting: Quartz sand, aluminum hydroxide, boric acid or boric anhydride, lithium carbonate, sodium carbonate, potassium carbonate or potassium nitrate, basic magnesium carbonate, calcium carbonate, titanium dioxide, tin oxide and yttrium oxide are weighed and mixed uniformly according to the ingredient requirements, and then placed in a glass melting furnace and melted at 1550°C for 18 hours;

[0060] (2) Clarification and homogenization: After the raw materials are melted into glass melt, the glass melt flows from the glass melting pool into the stirring pool and is fully stirred, and then flows into the clarification pool at 1400°C. The glass melt is clarified and homogenized for 6 hours to remove and absorb small bubbles, and then flows into the material basin to cool down;

[0061] (3) Tube drawing: After the glass liquid is cooled to 1200°C, it flows from the material basin to the feed channel and then to the forming nozzle. After passing through the forming nozzle, the glass liquid is pulled by the tube drawing machine to form a uniformly formed glass tube; the thickness of the glass tube is controlled at 2.5mm, and the inner diameter of the glass tube is controlled at Φ30.0mm;

[0062] (4) Cutting annealing: Cut the drawn glass tube into a certain length as required, and then place the cut glass tube in an annealing furnace at 580°C for 30 hours;

[0063] (5) Bottom sealing: The annealed glass tube is sealed with a flame at the bottom, and the tube mouth is burned with a flame to remove burrs. The microchannel plate screen plate segment to be gas-melted and pressed is placed into the glass tube. The length of the glass tube after bottom sealing is 2.0 times the length of the microchannel plate screen plate segment, and the length of the microchannel plate screen plate segment is 70 mm.

[0064] Example 2

[0065] Select raw materials according to the glass composition of Example 2 in Table 1 so that the ingredients meet the glass chemical composition of Table 1, and then prepare the cladding glass tube according to the following steps:

[0066] (1) Glass melting: Quartz sand, aluminum hydroxide, boric acid or boric anhydride, lithium carbonate, sodium carbonate, potassium carbonate or potassium nitrate, basic magnesium carbonate, calcium carbonate, titanium dioxide, tin oxide and yttrium oxide are weighed and mixed uniformly according to the ingredient requirements, and then placed in a glass melting furnace and melted at 1500°C for 24 hours;

[0067] (2) Clarification and homogenization: After the raw materials are melted into glass melt, the glass melt flows from the glass melting pool into the stirring pool and is fully stirred, and then flows into the clarification pool at 1450°C. The glass melt is clarified and homogenized for 5 hours to remove and absorb small bubbles, and then flows into the material basin to cool down;

[0068] (3) Tube drawing: After the glass liquid is cooled to 1350°C, the glass liquid flows from the material basin to the feed channel and then to the forming nozzle. After passing through the forming nozzle, the glass liquid is pulled by the tube drawing machine to form a uniformly formed glass tube; the thickness of the glass tube is controlled to be 4.0 mm, and the inner diameter of the glass tube is controlled to be Φ32.0 mm;

[0069] (4) Cutting annealing: Cut the drawn glass tube into a certain length as required, and then place the cut glass tube in an annealing furnace at 600°C for 24 hours;

[0070] (5) Bottom sealing: The annealed glass tube is sealed with a flame at the bottom, and the tube mouth is burned with a flame to remove burrs. The microchannel plate screen plate segment to be gas-melted and pressed is placed into the glass tube. The length of the glass tube after bottom sealing is 1.5 times the length of the microchannel plate screen plate segment, and the length of the microchannel plate screen plate segment is 150 mm.

[0071] Example 3

[0072] Select raw materials according to the glass composition of Example 3 in Table 1 so that the ingredients meet the glass chemical composition of Table 1, and then prepare the cladding glass tube according to the following steps:

[0073] (1) Glass melting: Quartz sand, aluminum hydroxide, boric acid or boric anhydride, lithium carbonate, sodium carbonate, potassium carbonate or potassium nitrate, basic magnesium carbonate, calcium carbonate, titanium dioxide, tin oxide and yttrium oxide are weighed and mixed uniformly according to the ingredient requirements, and then placed in a glass melting furnace and melted at 1600°C for 12 hours;

[0074] (2) Clarification and homogenization: After the raw materials are melted into glass melt, the glass melt flows from the glass melting pool into the stirring pool and is fully stirred, and then flows into the clarification pool at 1480°C. The glass melt is clarified and homogenized for 4 hours to remove and absorb small bubbles, and then flows into the material basin to cool down;

[0075] (3) Tube drawing: After the glass liquid is cooled to 1350°C, it flows from the material basin to the feed channel and then to the forming nozzle. After passing through the forming nozzle, the glass liquid is pulled by the tube drawing machine to form a uniformly formed glass tube; the thickness of the glass tube is controlled to be 1.0 mm, and the inner diameter of the glass tube is controlled to be Φ27 mm;

[0076] (4) Cutting annealing: Cut the drawn glass tube into a certain length as required, and then place the cut glass tube in an annealing furnace at 560°C for 36 hours;

[0077] (5) Bottom sealing: The annealed glass tube is sealed with a flame at the bottom, and the tube mouth is burned with a flame to remove burrs. The microchannel plate screen plate segment to be formed by gas melting and pressing is placed into the glass tube. The length of the glass tube after bottom sealing is 2.5 times the length of the microchannel plate screen plate segment, and the length of the microchannel plate screen plate segment is 50 mm.

[0078] Example 4

[0079] Select raw materials according to the glass composition of Example 4 in Table 1 so that the ingredients meet the glass chemical composition of Table 1, and then prepare the cladding glass tube according to the following steps:

[0080] (1) Glass melting: Quartz sand, aluminum hydroxide, boric acid or boric anhydride, lithium carbonate, sodium carbonate, potassium carbonate or potassium nitrate, basic magnesium carbonate, calcium carbonate, titanium dioxide, tin oxide and yttrium oxide are weighed and mixed uniformly according to the ingredient requirements, and then placed in a glass melting furnace and melted at 1520°C for 15 hours;

[0081] (2) Clarification and homogenization: After the raw materials are melted into glass melt, the glass melt flows from the glass melting pool into the stirring pool and is fully stirred, and then flows into the clarification pool at 1460°C. The glass melt is clarified and homogenized for 4 hours to remove and absorb small bubbles, and then flows into the material basin to cool down;

[0082] (3) Tube drawing: After the glass liquid is cooled to 1280°C, the glass liquid flows from the material basin to the feed channel and then to the forming nozzle. After passing through the forming nozzle, the glass liquid is pulled by the tube drawing machine to form a uniformly formed glass tube; the thickness of the glass tube is controlled at 2.0 mm, and the inner diameter of the glass tube is controlled at Φ31 mm;

[0083] (4) Cutting annealing: Cut the drawn glass tube into a certain length as required, and then place the cut glass tube in an annealing furnace at 570°C for 26 hours;

[0084] (5) Bottom sealing: The annealed glass tube is sealed with a flame at the bottom, and the tube mouth is burned with a flame to remove burrs. The microchannel plate screen plate segment to be gas-melted and pressed is placed into the glass tube. The length of the glass tube after bottom sealing is 1.8 times the length of the microchannel plate screen plate segment, and the length of the microchannel plate screen plate segment is 120 mm.

[0085] Example 5

[0086] Select raw materials according to the glass composition of Example 5 in Table 1 so that the ingredients meet the glass chemical composition of Table 1, and then prepare the cladding glass tube according to the following steps:

[0087] (1) Glass melting: Quartz sand, aluminum hydroxide, boric acid or boric anhydride, lithium carbonate, sodium carbonate, potassium carbonate or potassium nitrate, basic magnesium carbonate, calcium carbonate, titanium dioxide, tin oxide and yttrium oxide are weighed and mixed uniformly according to the ingredient requirements, and then placed in a glass melting furnace and melted at 1540°C for 20 hours;

[0088] (2) Clarification and homogenization: After the raw materials are melted into glass melt, the glass melt flows from the glass melting pool into the stirring pool and is fully stirred, and then flows into the clarification pool at 1470°C. The glass melt is clarified and homogenized for 5 hours to remove and absorb small bubbles, and then flows into the material basin to cool down;

[0089] (3) Tube drawing: After the glass liquid is cooled to 1320°C, the glass liquid flows from the material basin to the feed channel and then to the forming nozzle. After passing through the forming nozzle, the glass liquid is pulled by the tube drawing machine to form a uniformly formed glass tube; the thickness of the glass tube is controlled at 3.0 mm, and the inner diameter of the glass tube is controlled at Φ29 mm;

[0090] (4) Cutting annealing: Cut the drawn glass tube into a certain length as required, and then place the cut glass tube in an annealing furnace at 590°C for 25 hours;

[0091] (5) Bottom sealing: The annealed glass tube is sealed flat on the bottom with a flame, and the tube mouth is burned with a flame to remove burrs. The microchannel plate screen plate segment to be gas-melted and pressed is placed into the glass tube. The length of the glass tube after bottom sealing is 2.1 times the length of the microchannel plate screen plate segment, and the length of the microchannel plate screen plate segment is 100 mm.

[0092] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A cladding glass tube composition for gas melting and pressing, characterized in that: The following components are included in mole percentage:

2. The composition according to claim 1, characterized in that The following components are included in mole percentage:

3. The composition according to claim 2, characterized in that The following components are included in mole percentage:

4. A method for preparing a cladding glass tube for gas melting and pressing using the composition according to any one of claims 1 to 3, characterized in that: The following steps are involved: (1) Glass melting: Quartz sand, aluminum hydroxide, boric acid or boric anhydride, lithium carbonate, sodium carbonate, potassium carbonate or potassium nitrate, basic magnesium carbonate, calcium carbonate, titanium dioxide, tin oxide and yttrium oxide are weighed and mixed uniformly according to the ingredient requirements, and then placed in a glass melting furnace and melted at a first preset temperature for a first preset time; (2) Clarification and homogenization: After the raw materials are melted into glass melt, the glass melt flows from the glass melting pool into the stirring pool to be fully stirred, and then flows into the clarification pool at a second preset temperature. After the glass melt is clarified and homogenized for a second preset time to remove and absorb small bubbles, it flows into the material basin to cool down; (3) Tube drawing: After the glass liquid is cooled to a third preset temperature, the glass liquid flows from the material basin to the material channel and then to the forming nozzle. After the glass liquid passes through the forming nozzle, it is pulled by the tube drawing machine to form a uniformly formed glass tube; (4) Cutting and annealing: Cut the drawn glass tube into a certain length as required, and then place the cut glass tube into an annealing furnace for annealing; (5) Bottom sealing: The annealed glass tube is sealed with a flame at the bottom, and the tube mouth is burned with a flame to remove burrs to obtain a cladding glass tube with a sealed bottom.

5. The preparation method according to claim 4, characterized in that The first preset temperature is 1500-1600° C., and the first preset time is 12-24 hours; The second preset temperature is 1400-1480° C., and the second preset time is 4-6 hours.

6. The preparation method according to claim 5, characterized in that The third preset temperature is 1200-1350° C. The annealing temperature is 560-600° C., and the annealing time is 24-36 hours.

7. The preparation method according to claim 6, characterized in that During the tube drawing process, the thickness of the glass tube is controlled within 2.5±1.5 mm, and the inner diameter of the glass tube is controlled within Φ30.0±3.0 mm.

8. The preparation method according to claim 7, characterized in that The length of the glass tube after bottom sealing is 1.5 to 2.5 times the length of the microchannel plate screen section; the microchannel plate screen section is a 12-sided structure, and the length of the microchannel plate screen section is 50 to 150 mm.

9. A cladding glass tube for preparing a microchannel slab by gas melting and pressing, characterized in that: It is prepared according to the preparation method according to any one of claims 4 to 8.

10. The cladding glass tube according to claim 9 is used for placing microchannel plate screen segments in a microchannel plate blank prepared by gas melting and pressing technology, and the microchannel plate prepared by the cladding glass tube is used in a low-light image intensifier.

Images