Large-size special-shaped quartz porous ceramic antenna inner cover based on 3D printing and preparation method thereof

Abstract

The present invention relates to a large-sized, special-shaped quartz porous ceramic antenna inner cover based on 3D printing and a preparation method thereof. The method comprises the following steps: uniformly mixing, by weight, 20-30 parts of silica aerogel microspheres, 5-10 parts of quartz chopped fibers, 10-20 parts of aluminum dihydrogen phosphate solution, 5-10 parts of clay, and 60-80 parts of deionized water to obtain a 3D printing clay material capable of low-temperature sintering; aging and vacuum-kneading the 3D printing clay material, pressing the clay material into a barrel of a 3D printing device, and 3D printing a blank; and air-drying the blank, sintering it at a temperature of 500-600° C., and cooling it to obtain a large-sized, special-shaped quartz porous ceramic antenna inner cover. The method for preparing the large-sized, special-shaped quartz porous ceramic antenna inner cover based on 3D printing solves the problem in the prior art of large-sized, special-shaped porous quartz ceramic antenna inner covers caused by excessively high sintering temperatures.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printing porous ceramic materials, and in particular to a large-sized, special-shaped quartz porous ceramic antenna inner cover based on 3D printing and a preparation method thereof. Background Art

[0002] Porous quartz ceramics have a rich micro-nanopore structure, which gives the material excellent thermal insulation properties, a low dielectric constant, and low dielectric loss. Therefore, in the aerospace field, it is widely used to prepare antenna inner covers with multifunctional integration such as light weight, high temperature resistance, heat insulation, and wave transmission. At present, porous quartz ceramic wave-transmitting antenna inner covers with integrated functions such as light weight, high temperature resistance, heat insulation, and wave transmission used in the aerospace field are generally prepared by a molding process. The molding process for preparing porous quartz ceramic antenna inner covers requires the preparation of molds, which has a long production cycle and high production costs. Moreover, due to the high brittleness of the material, the product is easily damaged during the production process, the yield rate is low, and the overall cost is high.

[0003] 3D printing technology offers three advantages: First, it can manufacture complex components that are difficult or impossible to achieve using traditional methods. Second, it offers high molding efficiency, eliminating the need for pre-molding, shortening production cycles and reducing costs. Third, it allows for full process monitoring and stable control of the material's microstructure and properties. However, existing methods for producing porous quartz ceramic antenna inner covers using 3D printing suffer from significant shrinkage due to excessively high sintering temperatures (generally above 1300°C). For simple, small-sized porous quartz ceramic antenna inner covers or thermal insulation tiles, dimensional accuracy can be achieved through appropriate dimensional design compensation or grinding. However, for larger, irregular-shaped porous quartz ceramic antenna inner covers, this approach struggles to meet dimensional control requirements.

[0004] Therefore, in order to solve the above problems, the present invention urgently needs to provide a large-sized special-shaped quartz porous ceramic antenna inner cover based on 3D printing and a preparation method thereof. Summary of the Invention

[0005] The purpose of the present invention is to provide a large-sized special-shaped quartz porous ceramic antenna inner cover based on 3D printing and a preparation method thereof. By proposing a preparation method of a large-sized special-shaped quartz porous ceramic antenna inner cover based on 3D printing, the problem that the 3D printed large-sized special-shaped porous quartz ceramic antenna inner cover products in the prior art are large shrinkage caused by the high sintering temperature (generally above 1300°C) and the inability to meet the product size control requirements is solved.

[0006] The present invention provides a method for preparing a large-sized, special-shaped quartz porous ceramic antenna inner cover based on 3D printing, comprising the following steps:

[0007] According to the weight ratio, 20-30 parts of silica aerogel microspheres, 5-10 parts of quartz chopped fibers, 10-20 parts of aluminum dihydrogen phosphate solution, 5-10 parts of clay, and 60-80 parts of deionized water are mixed evenly to obtain a 3D printing mud material that can be sintered at a low temperature.

[0008] The 3D printing clay is aged and vacuum-kneaded, then pressed into the barrel of the 3D printing equipment to produce a 3D printed body.

[0009] After the embryo is dried in the shade, it is sintered at a low temperature of 500-600°C and cooled to obtain a large-sized special-shaped quartz porous ceramic antenna inner cover.

[0010] Preferably, the silica aerogel microspheres have a diameter of 2-3 μm.

[0011] Preferably, during the low-temperature sintering process, the temperature is raised from room temperature to 500-600°C at a heating rate of 3-5°C / min, kept for 240-300 minutes, and cooled naturally. Oxygen is introduced during the sintering process to ensure that trace organic matter in the green body is completely oxidized and removed.

[0012] Preferably, the large-sized special-shaped quartz porous ceramic antenna inner cover is a body of revolution or a special-shaped body with plane symmetry.

[0013] Preferably, when the large-sized special-shaped quartz porous ceramic antenna inner cover is a body of revolution, the diameter of the large end of the large-sized special-shaped quartz porous ceramic antenna inner cover is greater than 300 mm, the height is greater than 400 mm, and the wall thickness is greater than 10 mm;

[0014] When the large-sized special-shaped quartz porous ceramic antenna inner cover is a face-symmetrical special-shaped body, the large end of the large-sized special-shaped quartz porous ceramic antenna inner cover includes a long diameter and a short diameter, the long diameter is greater than 300mm, the short diameter is greater than 250mm, the height is greater than 400mm, and the wall thickness is greater than 10mm.

[0015] Preferably, the embryos are placed in a constant temperature and humidity chamber for shade drying, with an ambient temperature of 35-45° C., an ambient humidity of 40-50%, and a shade drying time of 8-10 days.

[0016] Preferably, during the shade drying process, the embryos need to be placed upside down once on the 4th to 5th day.

[0017] Preferably, the 3D printing rate is 2100-2500 mm / min, the nozzle diameter is 2.0-3.5 mm, and the printing layer height is 1.5-2.5 mm.

[0018] Preferably, the 3D printing clay is kneaded for 60-120 minutes, sealed and aged for 5-7 days, and vacuum-mixed for 3-5 times.

[0019] The present invention also provides a large-sized special-shaped quartz porous ceramic antenna inner cover obtained based on the preparation method of the large-sized special-shaped quartz porous ceramic antenna inner cover based on 3D printing as described in any one of the above.

[0020] The present invention provides a large-scale, special-shaped quartz porous ceramic antenna inner cover based on 3D printing and a preparation method thereof, which has the following improvements over the prior art:

[0021] 1. The present invention provides a method for preparing large-scale, irregularly shaped quartz porous ceramic antenna inner covers based on 3D printing. By using aluminum dihydrogen phosphate as a low-temperature sintering aid in the low-temperature sintering 3D printing clay, the sintering temperature can be reduced from the previously required temperature of over 1300°C to 500-600°C, and the product's sintering linear shrinkage can be reduced from over 5% to under 0.5%. This effectively suppresses sintering shrinkage during production and significantly improves the dimensional qualification rate of large-scale, irregularly shaped quartz porous ceramic antenna inner covers. This method enables the 3D printing and low-temperature sintering of large-scale, irregularly shaped quartz porous ceramic antenna inner covers. Furthermore, by using clay instead of an organic binder, the problem of incomplete removal of residual carbon from the original organic binder during low-temperature sintering in the antenna inner cover product is overcome, ensuring that the material retains its excellent dielectric and wave transmission properties.

[0022] 2. The preparation method of the large-sized special-shaped quartz porous ceramic antenna inner cover based on 3D printing provided by the present invention, through the reasonable proportion of the porous quartz ceramic clay material for 3D printing that can be sintered at low temperature, the clay material has suitable viscosity and plasticity, and can be used for direct writing 3D printing to prepare large-sized special-shaped porous quartz ceramic antenna inner cover blanks, thereby overcoming the problems of the traditional molding process for preparing porous quartz ceramic antenna inner cover, which requires mold opening, has a long production cycle, is brittle, the product is easily damaged during the production process, has a low yield rate, and has a high overall cost.

[0023] 3. The present invention provides a method for preparing a large-scale, irregularly shaped quartz porous ceramic antenna inner dome using 3D printing. Silica aerogel microspheres are commercially available at a price of 1,000-2,000 yuan / kg; quartz chopped fiber is commercially available at a price of 800-1,200 yuan / kg; aluminum dihydrogen phosphate solution is commercially available at a price of 30-50 yuan / kg; and kaolin (clay) is commercially available at a price of 10-15 yuan / kg. Deionized water is homemade, and the material preparation cost is controlled within 3,000 yuan / kg. Compared to porous quartz ceramic antenna inner domes prepared using existing molding processes, the method for preparing large-scale, irregularly shaped quartz porous ceramic antenna inner domes using 3D printing of the present invention can save approximately 7,000 yuan / kg. Furthermore, since all of the above raw materials are directly commercially available, no preparation or mold making is required, resulting in a high product yield and significantly shortening the production cycle by over 50%. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 This is a flow chart of the steps for preparing a large-scale, special-shaped quartz porous ceramic antenna inner cover based on 3D printing;

[0026] Figure 2 Schematic diagram of the inner cover structure of a large-scale, special-shaped quartz porous ceramic antenna (side view);

[0027] Figure 3 Schematic diagram of the inner cover structure of a large-sized, special-shaped quartz porous ceramic antenna (bottom view). DETAILED DESCRIPTION

[0028] The technical solution of the present invention will be described clearly and completely below. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0029] The present invention provides a method for preparing a large-sized, special-shaped quartz porous ceramic antenna inner cover based on 3D printing, comprising the following steps:

[0030] S1) uniformly mixing, by weight, 20-30 parts of silica aerogel microspheres, 5-10 parts of quartz chopped fibers, 10-20 parts of aluminum dihydrogen phosphate solution, 5-10 parts of clay, and 60-80 parts of deionized water to obtain a 3D printing mud material that can be sintered at a low temperature;

[0031] S2) The 3D printing clay material is aged and vacuum-mixed, and then pressed into the barrel of the 3D printing device to 3D print the embryo;

[0032] S3) After the embryo is dried in the shade, it is sintered at a low temperature of 500-600° C. and cooled to obtain a large-sized, special-shaped quartz porous ceramic antenna inner cover.

[0033] Specifically, the silica aerogel microspheres have a diameter of 2-3 μm.

[0034] Specifically, during the low-temperature sintering process, the temperature is raised from room temperature to 500-600°C at a heating rate of 3-5°C / min, kept for 240-300 minutes, and naturally cooled. Oxygen is introduced during the sintering process to ensure that trace organic matter in the green body is completely oxidized and removed.

[0035] Specifically, the large-sized special-shaped quartz porous ceramic antenna inner cover is a body of revolution or a special-shaped body with plane symmetry.

[0036] Specifically, when the large-sized special-shaped quartz porous ceramic antenna inner cover is a rotating body, the diameter of the large end of the large-sized special-shaped quartz porous ceramic antenna inner cover is greater than 300 mm, the height is greater than 400 mm, and the wall thickness is greater than 10 mm;

[0037] When the large-sized special-shaped quartz porous ceramic antenna inner cover is a face-symmetrical special-shaped body, the large end of the large-sized special-shaped quartz porous ceramic antenna inner cover includes a long diameter and a short diameter, the long diameter is greater than 300mm, the short diameter is greater than 250mm, the height is greater than 400mm, and the wall thickness is greater than 10mm.

[0038] Specifically, the embryos are placed in a constant temperature and humidity chamber for shade drying, with an ambient temperature of 35-45° C., an ambient humidity of 40-50%, and a shade drying time of 8-10 days.

[0039] Specifically, during the shade drying process, the embryo needs to be placed upside down on the 4th to 5th day.

[0040] Specifically, the 3D printing rate is 2100-2500mm / min, the nozzle diameter is 2.0-3.5mm, and the printing layer height is 1.5-2.5mm.

[0041] Specifically, the 3D printing clay material is mixed for 60-120 minutes, sealed and aged for 5-7 days, and vacuum-kneaded for 3-5 times.

[0042] Specifically, before 3D printing, the 3D image of the large-scale special-shaped antenna inner cover is imported into the Simplify 3D program, the printing process parameters are set, the 3D printing program code is generated, the 3D printing equipment is connected, and the embryo is 3D printed.

[0043] Specifically, the density of the large-sized special-shaped quartz porous ceramic antenna inner cover is 0.35-0.55g / cm 3 , dielectric constant 1.4-1.6, dielectric loss <0.008, material tensile strength >0.5MPa, compressive strength >1.5MPa.

[0044] The present invention also provides a large-sized special-shaped quartz porous ceramic antenna inner cover obtained based on the preparation method of the large-sized special-shaped quartz porous ceramic antenna inner cover based on 3D printing as described in any one of the above.

[0045] The present invention provides a method for preparing a large-scale, special-shaped quartz porous ceramic antenna inner cover based on 3D printing. Aluminum dihydrogen phosphate is used as a low-temperature sintering aid in the 3D printing clay material capable of low-temperature sintering. The sintering temperature can be reduced from the original required temperature of over 1300°C to 500-600°C, and the product's sintering linear shrinkage can be reduced from over 5% to under 0.5%. This effectively suppresses sintering shrinkage during product production and significantly improves the dimensional qualification rate of large-scale, special-shaped quartz porous ceramic antenna inner covers. This method enables 3D printing and low-temperature sintering of large-scale, special-shaped quartz porous ceramic antenna inner covers. The use of clay instead of an organic binder overcomes the problem of incomplete removal of residual carbon from the original organic binder during low-temperature sintering, ensuring that the material retains excellent dielectric and wave-transmitting properties. Furthermore, the silica aerogel microspheres act as a low-density filler, providing both thermal insulation and wave-transmitting properties, ensuring the material's excellent dielectric and wave-transmitting properties.

[0046] The present invention provides a method for preparing a large-sized, special-shaped quartz porous ceramic antenna inner cover based on 3D printing. By rationally proportioning porous quartz ceramic clay materials that can be sintered at low temperatures and have suitable viscosity and plasticity, the method can be used for direct writing 3D printing to prepare large-sized, special-shaped porous quartz ceramic antenna inner cover blanks. This overcomes the problems of traditional molding processes for preparing porous quartz ceramic antenna inner covers, which require mold opening, have a long production cycle, are brittle, are easily damaged during the production process, have a low yield rate, and have a high overall cost.

[0047] The existing molding process for porous quartz ceramic antenna inner covers, a product of the present invention, is not suitable for producing large-scale, irregularly shaped porous quartz ceramic antenna inner covers. Furthermore, the production process requires molds, resulting in a long production cycle. The product is easily damaged during demolding and processing, resulting in a low yield and a high manufacturing cost of 10,000-12,000 yuan per kilogram. However, the present invention provides a method for producing large-scale, irregularly shaped porous quartz ceramic antenna inner covers using 3D printing. The silica aerogel microspheres available on the market cost 1,000-2,000 yuan per kilogram, quartz chopped fibers cost 800-1,200 yuan per kilogram, aluminum dihydrogen phosphate solution cost 30-50 yuan per kilogram, and kaolin (clay) costs 10-15 yuan per kilogram. Deionized water is homemade, keeping the material preparation cost within 3,000 yuan per kilogram. Compared with the porous quartz ceramic antenna inner cover prepared by the existing molding process, the large-size special-shaped quartz porous ceramic antenna inner cover obtained by the preparation method of the large-size special-shaped quartz porous ceramic antenna inner cover printed by 3D printing of the present invention can save about 7,000 yuan / kg in cost. At the same time, the above raw materials are directly obtained from the market, and no preparation or mold making is required. The product qualification rate is high, and the product production cycle can be significantly shortened by more than 50%.

[0048] Example 1

[0049] A method for preparing a large-sized, special-shaped quartz porous ceramic antenna inner cover based on 3D printing includes the following steps:

[0050] 101) According to parts by weight, 25 parts of silica aerogel microspheres, 5 parts of quartz chopped fibers, 15 parts of aluminum dihydrogen phosphate solution, 8 parts of clay, and 65 parts of deionized water were mixed and kneaded for 80 minutes to obtain a 3D printing mud material that can be sintered at low temperature;

[0051] 102) The 3D printing clay was sealed and aged for 5 days, vacuum-kneaded for 5 times, and then pressed into the barrel of a 3D printing device to 3D print the body. Prior to 3D printing, the 3D image of the antenna inner cover was imported into the Simplify 3D program, the printing process parameters were set, the 3D printing program code was generated, the 3D printing device was connected, and the body was 3D printed. The 3D printing speed was 2300 mm / min, the nozzle diameter was 2.5 mm, and the print layer height was 1.8 mm.

[0052] 103) The embryo is placed in a constant temperature and humidity chamber for shade drying at an ambient temperature of 40°C and a humidity of 40% for 8 days. During the shade drying process, the embryo is placed upside down on the 4th day. After sintering at 600°C and cooling, a large-sized, special-shaped quartz porous ceramic antenna inner cover is obtained.

[0053] The silica aerogel microspheres in this embodiment have a diameter of 2-3 μm.

[0054] During the low-temperature sintering process of this embodiment, the temperature was raised from room temperature to 600°C at a heating rate of 4°C / min, kept at that temperature for 240 minutes, and naturally cooled. Oxygen was introduced during the sintering process to ensure that trace organic matter in the green body was completely oxidized and removed.

[0055] The large-sized, special-shaped quartz porous ceramic antenna inner cover of this embodiment is a body of revolution.

[0056] The dimensions of the large-sized, special-shaped quartz porous ceramic antenna inner cover of this embodiment are: a large end diameter of 320 mm, a total height of 450 mm, and a wall thickness of 11 mm.

[0057] The density of the large-sized special-shaped quartz porous ceramic antenna inner cover obtained in this embodiment is 0.44g / cm 3 , thermal conductivity 0.056W / m·K, dielectric constant 1.55, dielectric loss tangent 7.5×10 -3 , compression strength 2.5MPa, tensile strength 0.7MPa.

[0058] According to the preparation method of large-scale special-shaped quartz porous ceramic antenna inner cover based on 3D printing, a test piece was prepared. The size of the test piece was 27×27×30 mm. The shrinkage rate of the test piece was tested. The test results are shown in Table 1.

[0059] Example 2

[0060] A method for preparing a large-sized, special-shaped quartz porous ceramic antenna inner cover based on 3D printing includes the following steps:

[0061] 201) According to parts by weight, 20 parts of silica aerogel microspheres, 10 parts of quartz chopped fibers, 20 parts of aluminum dihydrogen phosphate solution, 10 parts of clay, and 80 parts of deionized water were mixed and kneaded for 120 minutes to obtain a 3D printing mud material that can be sintered at low temperature;

[0062] 202) The 3D printing clay was sealed and aged for 7 days, vacuum-kneaded for 3 times, and then pressed into the barrel of a 3D printing device to 3D print the body. Prior to 3D printing, the 3D image of the antenna inner cover was imported into the Simplify 3D program, the printing process parameters were set, the 3D printing program code was generated, the 3D printing device was connected, and the body was 3D printed. The 3D printing speed was 2100 mm / min, the nozzle diameter was 3.5 mm, and the printing layer height was 2.5 mm.

[0063] 203) The embryo is placed in a constant temperature and humidity chamber for shade drying at an ambient temperature of 35°C and a humidity of 50% for 10 days. During the shade drying process, the embryo is placed upside down on the fifth day. After sintering at 500°C and cooling, a large-sized, special-shaped quartz porous ceramic antenna inner cover is obtained.

[0064] The silica aerogel microspheres in this embodiment have a diameter of 2-3 μm.

[0065] During the low-temperature sintering process of this embodiment, the temperature was raised from room temperature to 500°C at a heating rate of 5°C / min, kept at that temperature for 300 minutes, and naturally cooled. Oxygen was introduced during the sintering process to ensure that trace organic matter in the green body was completely oxidized and removed.

[0066] The large-sized special-shaped quartz porous ceramic antenna inner cover of this embodiment is a special-shaped body with plane symmetry, such as Figure 2 and Figure 3 shown.

[0067] The dimensions of the large-sized special-shaped quartz porous ceramic antenna inner cover of this embodiment are: large end long diameter 320mm, large end short diameter 260mm, total height 460mm, and wall thickness 12mm.

[0068] The density of the large-sized special-shaped quartz porous ceramic antenna inner cover obtained in this embodiment is 0.46g / cm 3, thermal conductivity is 0.061 W / m·K, dielectric constant is 1.58, and dielectric loss tangent is less than 7.8×10 -3 , compression strength 2.7MPa, tensile strength 0.8MPa.

[0069] According to the preparation method of large-scale special-shaped quartz porous ceramic antenna inner cover based on 3D printing, a test piece was prepared. The size of the test piece was 27×27×30 mm. The shrinkage rate of the test piece was tested. The test results are shown in Table 1.

[0070] Example 3

[0071] A method for preparing a large-sized, special-shaped quartz porous ceramic antenna inner cover based on 3D printing includes the following steps:

[0072] 301) According to parts by weight, 30 parts of silica aerogel microspheres, 8 parts of quartz chopped fibers, 10 parts of aluminum dihydrogen phosphate solution, 5 parts of clay, and 60 parts of deionized water were mixed and kneaded for 60-120 minutes to obtain a 3D printing mud material that can be sintered at low temperature;

[0073] 302) The 3D printing clay was sealed and aged for 6 days, vacuum-kneaded 4 times, and then pressed into the barrel of a 3D printing device to produce a 3D printed body. Prior to 3D printing, a 3D image of a large-scale, irregularly shaped antenna inner cover was imported into the Simplify 3D program, printing process parameters were set, 3D printing program code was generated, and the 3D printing device was connected to produce the 3D printed body. The 3D printing speed was 2500 mm / min, the nozzle diameter was 2.0 mm, and the printing layer height was 1.8 mm.

[0074] 303) The embryo is placed in a constant temperature and humidity chamber for shade drying at an ambient temperature of 40°C and a humidity of 40% for 10 days. During the shade drying process, the embryo is placed upside down on the fifth day and sintered at 600°C and cooled to obtain a large-sized, special-shaped quartz porous ceramic antenna inner cover.

[0075] The silica aerogel microspheres in this embodiment have a diameter of 2-3 μm.

[0076] During the low-temperature sintering process of this embodiment, the temperature was raised from room temperature to 600°C at a heating rate of 4°C / min, kept at that temperature for 300 minutes, and naturally cooled. Oxygen was introduced during the sintering process to ensure that trace organic matter in the green body was completely oxidized and removed.

[0077] The large-sized special-shaped quartz porous ceramic antenna inner cover of this embodiment is a special-shaped body with plane symmetry, such as Figure 2 and Figure 3 shown.

[0078] The dimensions of the large-sized special-shaped quartz porous ceramic antenna inner cover of this embodiment are: the large end long diameter is 320mm, the large end short diameter is 300mm, the total height is 480mm, and the wall thickness is 12mm.

[0079] The density of the large-sized special-shaped quartz porous ceramic antenna inner cover obtained in this embodiment is 0.43g / cm 3 , thermal conductivity 0.053 W / m·K, dielectric constant 1.45, dielectric loss tangent less than 6.3×10 -3 , compression strength is greater than 2.3MPa, and tensile strength is 0.6MPa.

[0080] The silica aerogel microspheres used in the present invention are provided by Hangzhou Nanosilicon Microsphere Technology Co., Ltd., with an average diameter of 2-3 μm and a bulk density of 0.24 g / cm 3 The quartz chopped fibers were 300-500 μm in length and were obtained by sieving spheroidal graphite from quartz fibers provided by Hubei Feilihua Quartz Glass Co., Ltd. The aluminum dihydrogen phosphate solution was provided by Henan Jieyang New Materials Co., Ltd. with an effective content of 40-50%; the clay was provided by Zibo Jinchi Clay Processing Plant with a sand content of <30%; and the deionized water was homemade.

[0081] According to the preparation method of large-scale special-shaped quartz porous ceramic antenna inner cover based on 3D printing, a test piece was prepared. The size of the test piece was 27×27×30 mm. The shrinkage rate of the test piece was tested. The test results are shown in Table 1.

[0082] Comparative Example 1

[0083] The only difference between this comparative example and Example 1 is that the conventional silica sol is used instead of the aluminum dihydrogen phosphate solution as the high-temperature sintering aid, and the sintering temperature is set to 1350°C.

[0084] According to the preparation method of large-scale special-shaped quartz porous ceramic antenna inner cover based on 3D printing, a test piece with a size of 27×27×30mm was prepared. The sintering linear shrinkage, density, mechanical, thermal and electrical properties of the test piece were tested. The results are shown in Table 1.

[0085] Comparative Example 2

[0086] The only difference between this comparative example and Example 1 is that a traditional organic binder 3D printing molding aid is used instead of clay. The organic binder is hydroxypropyl methylcellulose. A test piece is prepared according to the preparation method of a large-size, special-shaped quartz porous ceramic antenna inner cover based on 3D printing. The size of the test piece is 27×27×30 mm. The test piece is tested for shrinkage, density, mechanical, thermal, and electrical properties. The results are shown in Table 1.

[0087] Table 1 Physical properties of large-scale special-shaped quartz porous ceramic antenna inner cover based on 3D printing

[0088]

[0089] The data of Comparative Example 1 show that in Comparative Example 1, no aluminum dihydrogen phosphate solution is added. When silica sol is selected as a high-temperature sintering aid, the mechanical, thermal, and electrical properties of the material can meet the design requirements only when sintered at 1350°C. However, due to the high-temperature sintering, the obtained test piece has obvious shrinkage problems compared with the test piece obtained in Example 1, and cannot meet the size control requirements of the large-sized special-shaped quartz porous ceramic antenna inner cover.

[0090] The data of Comparative Example 2 show that, compared with Example 1, the use of aluminum dihydrogen phosphate as a sintering aid can achieve low-temperature sintering to prepare a large-sized, special-shaped quartz porous ceramic antenna inner cover, and the sintering line shrinkage meets the product size control requirements. However, when a traditional organic binder is used as the binder for 3D printing of the material, the dielectric constant and dielectric loss of the obtained material are significantly higher, which cannot meet the design requirements of the material's electrical properties.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a large-scale, special-shaped quartz porous ceramic antenna inner cover based on 3D printing, characterized by: The steps include: According to the weight ratio, 20-30 parts of silica aerogel microspheres, 5-10 parts of quartz chopped fibers, 10-20 parts of aluminum dihydrogen phosphate solution, 5-10 parts of clay, and 60-80 parts of deionized water are mixed evenly to obtain a 3D printing mud material that can be sintered at a low temperature. The 3D printing clay is aged and vacuum-kneaded, then pressed into the barrel of the 3D printing equipment to produce a 3D printed body. After the embryo is dried in the shade, it is sintered at 500-600℃ and cooled to obtain a large-sized, special-shaped quartz porous ceramic antenna inner cover; The diameter of silica aerogel microspheres is 2-3 μm.

2. The method for preparing a large-sized, special-shaped quartz porous ceramic antenna inner cover based on 3D printing according to claim 1, characterized in that: During the low-temperature sintering process, the temperature is raised from room temperature to 500-600°C at a heating rate of 3-5°C / min, kept for 240-300 minutes, and cooled naturally. Oxygen is introduced during the sintering process to ensure that trace organic matter in the green body is completely oxidized and removed.

3. The method for preparing a large-sized, special-shaped quartz porous ceramic antenna inner cover based on 3D printing according to claim 1, characterized in that: The inner cover of the large-sized special-shaped quartz porous ceramic antenna is a rotational body or a special-shaped body with plane symmetry.

4. The method for preparing a large-sized, special-shaped quartz porous ceramic antenna inner cover based on 3D printing according to claim 3, characterized in that: When the inner cover of the large-sized special-shaped quartz porous ceramic antenna is a rotating body, the diameter of the large end of the inner cover of the large-sized special-shaped quartz porous ceramic antenna is greater than 300mm, the height is greater than 400mm, and the wall thickness is greater than 10mm; When the large-sized special-shaped quartz porous ceramic antenna inner cover is a face-symmetrical special-shaped body, the large end of the large-sized special-shaped quartz porous ceramic antenna inner cover includes a long diameter and a short diameter, the long diameter is greater than 300mm, the short diameter is greater than 250mm, the height is greater than 400mm, and the wall thickness is greater than 10mm.

5. The method for preparing a large-sized, special-shaped quartz porous ceramic antenna inner cover based on 3D printing according to claim 1, characterized in that: The embryos are placed in a constant temperature and humidity chamber for shade drying at an ambient temperature of 35-45°C and a humidity of 40-50%. The shade drying time is 8-10 days.

6. The method for preparing a large-sized, special-shaped quartz porous ceramic antenna inner cover based on 3D printing according to claim 1, characterized in that: During the shade drying process, the embryo needs to be placed upside down on the 4th to 5th day.

7. The method for preparing a large-sized, special-shaped quartz porous ceramic antenna inner cover based on 3D printing according to claim 1, characterized in that: The 3D printing speed is 2100-2500mm / min, the nozzle diameter is 2.0-3.5mm, and the printing layer height is 1.5-2.5mm.

8. The method for preparing a large-sized, special-shaped quartz porous ceramic antenna inner cover based on 3D printing according to claim 1, characterized in that: The 3D printing clay material is mixed for 60-120 minutes, sealed and aged for 5-7 days, and vacuum-kneaded for 3-5 times.

9. A large-sized, special-shaped, porous quartz ceramic antenna inner cover obtained by the method for preparing a large-sized, special-shaped, porous quartz ceramic antenna inner cover based on 3D printing according to any one of claims 1 to 8.

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