A 3D-printed insulator, its fabrication method, and its application.

Abstract

This application discloses a 3D-printed insulator, its fabrication method, and its application, belonging to the field of high-voltage insulation technology. The insulator is fabricated using an insulating medium via 3D printing. Multiple through-holes are formed on the first surface of the insulator, and a cavity is formed inside the insulator. All the through-holes communicate with the cavity. The first surface is a surface along the electric field. Because multiple through-holes are formed on the surface of the insulator along the electric field, during flashover, electrons pass through the through-holes into the cavity. Electrons excited at the bottom of the cavity are difficult to pass through the through-holes and return to the insulator surface, thus giving the insulator better surface secondary electron avalanche suppression effect and higher vacuum surface dielectric strength.

Description

Technical Field

[0001] This application relates to an insulator based on 3D printing, its preparation method and application, belonging to the field of high voltage insulation technology. Background Technology

[0002] Solid insulators are indispensable key components in vacuum insulation systems, primarily serving to isolate high and low potentials and provide mechanical support. However, the surface breakdown voltage of an insulator in a vacuum is far lower than the volume breakdown voltage of a vacuum gap or material of equal spacing, making it a weak link in vacuum insulation systems. This has become one of the key technological bottlenecks restricting the development of equipment such as spacecraft, pulsed power equipment, high-energy particle accelerators, and semiconductor manufacturing and processing towards high power, miniaturization, and integration. Therefore, developing insulators with high vacuum surface dielectric strength is of great significance for the safe operation, reliability, and performance improvement of related equipment in vacuum insulation systems.

[0003] Vacuum surface flashover is a phenomenon caused by secondary electron avalanches leading to low-pressure plasma discharge along the surface of a solid dielectric. Its development can be divided into three stages: the initial stage (cathode-induced electron emission), the development stage (secondary electron multiplication), and the breakdown stage (gas desorption ionization and breakdown). Therefore, to improve the surface dielectric strength of a vacuum insulation system, it is necessary to suppress the development of at least one stage of the flashover process. Based on this theory, researchers both domestically and internationally have proposed numerous methods to suppress flashover.

[0004] To suppress the development of flashover initiation, methods such as optimizing the insulation structure and using bulk / surface functionally graded materials (FGMs) have been proposed to suppress cathode field-induced electron emission. Among these, FGMs, by controlling the spatial distribution of the dielectric parameters (conductivity and dielectric constant) of the insulating material to actively homogenize the electric field and alleviate local electric field distortion, are considered the most promising method for improving overall dielectric strength. However, despite numerous attempts (such as lamination, centrifugation, flexible casting, and 3D printing), the preparation of FGMs remains a critical technical challenge for their engineering applications. To suppress the development of flashover and reduce the secondary electron multiplication process, methods including matrix modification (such as nanocomposites, chemical grafting, and molecular modification) and surface treatment (such as fluorination, plasma treatment, composite coatings, film deposition, and surface microstructures) have been proposed. However, most of these methods suffer from limited improvement effects, complex processes, and limitations in mass production, hindering large-scale industrial applications. To suppress the breakdown stage of flashover, the main methods used are high vacuum or heat treatment to remove surface-adsorbed gases, reducing the amount of gas desorption and ionization during the breakdown stage. While this method is simple, its improvement effect is relatively limited. Therefore, there is still a need to develop new surface dielectric enhancement technologies that offer significant improvement, good mechanical properties, simple processes, large-scale fabrication capabilities, and are suitable for practical applications.

[0005] 3D printing technology offers advantages such as eliminating the need for molds, enabling the printing of irregularly shaped structures, and providing high printing precision, demonstrating great potential in the fabrication of high-performance insulators. However, the surface dielectric strength of conventional 3D-printed insulator structures remains relatively low, severely hindering the application of 3D printing technology in the field of electrical insulation. Summary of the Invention

[0006] To address the aforementioned issues, a 3D-printed insulator is provided. This insulator has multiple through holes along its surface in the electric field. During flashover, electrons pass through these through holes into the cavity. Electrons excited at the bottom of the cavity are unlikely to pass through the through holes and return to the insulator surface. This results in the insulator having better surface secondary electron avalanche suppression and higher vacuum surface dielectric strength.

[0007] According to one aspect of this application, a 3D-printed insulator is provided, wherein the insulator is made of an insulating medium and prepared by 3D printing, wherein the insulator has a plurality of through holes on a first surface and a cavity is provided inside the insulator, wherein the plurality of through holes are connected to the cavity, and the first surface is a surface along an electric field.

[0008] This insulator is manufactured using 3D printing. During the manufacturing process, an insulator with through holes and cavities is directly produced. When this insulator is used in an electric field, because the insulator has through holes along the surface of the electric field, electrons in the electron avalanche during flashover will pass through the through holes and enter the cavity. The electrons entering the cavity bombard the bottom surface of the cavity and excite fewer electrons. The electrons entering the cavity have low energy and are difficult to pass through the through holes and return to the surface of the insulator, thus achieving the purpose of significantly suppressing the electron multiplication process. Finally, an insulator with high surface dielectric strength is obtained.

[0009] Optionally, the depth of the cavity is 1–10 mm, preferably 3–5 mm. The deeper the cavity, the more difficult it is for electrons within the cavity to return to the insulator surface, resulting in higher vacuum surface dielectric strength of the insulator. If the cavity depth is greater than 10 mm, it will cause a decrease in the mechanical strength of the insulator. A cavity depth of 3–5 mm can achieve the best effect of suppressing electron multiplication and maintaining the mechanical strength of the insulator.

[0010] Optionally, the opening area of ​​the through hole is 0.25 mm. 2 -25mm 2 The spacing between adjacent through holes is 0.5-5 mm, and the depth of each through hole is no greater than 5 mm. The combination of the through hole opening area and the spacing between adjacent through holes facilitates the 3D printing of the insulator, ensuring the through holes are clearly visible after 3D printing. It also ensures that electrons fall into the cavity while preventing electrons from returning to the insulator surface, further improving the suppression of electron multiplication. If the through hole opening area is too small, electrons in the electric field will bypass the hole, preventing them from entering the cavity and thus failing to suppress electron multiplication.

[0011] Optionally, the through holes on the first surface are a periodic or aperiodic array, and the shape of the through holes is selected from any one or more of the following: circular, square, rectangular, polygonal, or irregular shapes.

[0012] Optionally, the total opening area of ​​the plurality of through holes accounts for 30-80% of the total area of ​​the first surface. This proportion of the total area of ​​the through holes ensures that most of the electrons fall into the cavity, and, in conjunction with the depth of the cavity, keeps the electrons inside the cavity, thereby suppressing the development of electron avalanche during flashover on the insulator surface.

[0013] Optionally, the insulator is a flat plate insulator or a post insulator.

[0014] Optionally, the surface of the insulator and at least the bottom surface of the cavity are covered with a thin film with a low secondary electron emission coefficient.

[0015] During flashover, electrons from electron avalanches bombard the bottom surface of the cavity and the surface of the insulator, which have a low secondary electron emission coefficient. This can excite fewer electrons, reducing the number of electrons and further decreasing the probability of secondary electrons returning to the insulator surface. This significantly suppresses electron multiplication and ultimately results in an insulator with higher surface dielectric strength.

[0016] Preferably, the thickness of the thin film is 20-1000 nm. This thickness can reduce the probability of electron excitation. If the film thickness is less than 20 nm, the effect of suppressing electron excitation in the cavity is not obvious. If the film thickness is greater than 1000 nm, the film is prone to local peeling, which cannot guarantee the long-term use of the insulator.

[0017] Optionally, the thin film comprises any one or more of metal oxides, inorganic non-metals, or fluorine-containing materials.

[0018] Preferably, the thin film is selected from any one or more of copper oxide, cobalt oxide, zinc oxide, chromium oxide, and titanium nitride. These materials have relatively simple preparation processes and also possess lower secondary electron emission coefficients, resulting in a more significant suppression of electron excitation.

[0019] More preferably, the thin film is selected from chromium oxide and titanium nitride, wherein the proportion of titanium nitride in the overall thin film is 10%-15%. Under this setting, titanium nitride can be uniformly dispersed in chromium oxide to form a dense and uniform thin film. After multiple experiments, it has been verified that the number of electrons bombarded on chromium oxide and titanium nitride decreases most significantly. Under the same specifications of through holes and cavities, the vacuum surface dielectric strength of the insulator using this material thin film reaches the highest level.

[0020] Optionally, the coating method for the thin film is selected from any one or more of magnetron sputtering, spraying, atomic layer deposition, chemical vapor deposition, and physical vapor deposition.

[0021] Preferably, the film coating method adopts magnetron sputtering. The thin film layer on the bottom surface of the cavity is prepared by magnetron sputtering. This method is mature and simple, with low cost, uniform film thickness, good film material dispersion, and can be mass-produced, showing good prospects for large-scale industrial preparation.

[0022] Optionally, the 3D printing is selected from any one of stereolithography (SLA), selective laser fusion (SLS), and fused deposition modeling (FDM).

[0023] According to another aspect of this application, a method for fabricating an insulator based on 3D printing as described in any of the above claims is provided, comprising the following steps:

[0024] (1) Construct a geometric CAD model of the insulator, divide the model into multiple geometric units and generate an STL file of the model, and use slicing software to convert the STL file into manufacturing data for the 3D printing device.

[0025] (2) The manufacturing data in step (1) is sent to the 3D printing equipment, the insulating medium is used to print the insulator print, and the uncured medium on the surface of the insulator print is cleaned off and then dried.

[0026] (3) Post-process the insulator print after drying in step (2) to obtain post-processed insulators;

[0027] (4) Cover the surface of the post-processed insulator and at least the bottom surface of the cavity with a thin film with a low secondary electron emission coefficient, and dry it to obtain the 3D printed insulator.

[0028] The insulator print in step (2) will be partially cured during printing. Therefore, after printing, the uncured medium on the surface of the insulator print is washed away in at least one aqueous solution of anhydrous ethanol or acetone. Then, in step (3), the insulator print can be completely cured to obtain an insulator with a fixed shape and a certain mechanical strength.

[0029] Optionally, when the insulating medium is a photocurable resin, the post-treatment temperature in step (3) is 20–80°C, and the curing time is 2–5 hours. When the insulating medium is a photocurable resin, stereolithography 3D printing technology is used. This technology produces insulators with high precision, and the edges and sidewalls of each through hole can be clearly printed, resulting in insulators with high dimensional consistency with the model. This treatment temperature and time can achieve complete curing of the printed insulator parts and avoid plastic deformation of the printed insulator parts during the curing process, while improving the curing efficiency of the printed insulator parts.

[0030] Optionally, the drying in step (4) involves placing the insulator covered with the film in a vacuum oven and drying it at 30–80°C for 1–5 hours. Drying after covering with the film can improve the bonding strength between the film and the insulator, improve the adhesion of the film, thereby preventing the film from falling off. At the same time, it can also remove adsorbed gases on the surface of the insulator, which is beneficial to improving the vacuum surface electrical resistance of the insulator.

[0031] According to one aspect of this application, the 3D-printed insulators described in any of the preceding claims or the 3D-printed insulators prepared by any of the preceding claims are provided for use in insulating components in high-energy particle accelerators, spacecraft, vacuum circuit breakers, pulsed power equipment, and semiconductor manufacturing and processing equipment.

[0032] Optionally, depending on the selected 3D printing technology, the insulating medium is selected from any one or more of epoxy acrylate resin, polyurethane acrylate resin, polyester acrylate resin, amino acrylate resin, nylon, polycarbonate, polyphenylsulfone, polylactic acid, polyimide, and ceramics.

[0033] The beneficial effects of this application include, but are not limited to:

[0034] 1. According to the 3D-printed insulator of this application, structurally, the through holes and cavities can capture electrons in the electron avalanche during flashover, thus significantly suppressing the multiplication of secondary electrons; in terms of chemical composition, the low secondary electron emission film covering the surface of the insulator and the bottom surface of the cavity can effectively reduce the secondary electron emission coefficient of the material surface, thereby achieving dual suppression of the development of electron avalanche during flashover on the insulator surface from both structural and compositional perspectives, ultimately greatly improving the vacuum surface dielectric strength of the insulator.

[0035] 2. According to the 3D-printed insulator of this application, the low secondary electron emission coefficient thin film on the bottom surface of the cavity is not subject to external wear, so the thin film can maintain the function of exciting fewer secondary electrons for a long time.

[0036] 3. According to the 3D-printed insulator of this application, the designed cavity structure has a size in the millimeter range, which is negligible compared to the size of the insulator body. Therefore, the overall mechanical properties of the insulator are well maintained.

[0037] 4. According to the method for preparing insulators based on 3D printing in this application, 3D printing technology can be used to prepare complex structures, and the printing accuracy of the insulators is high. It is suitable for large-scale preparation of insulators with through holes and cavities. Attached Figure Description

[0038] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0039] Figure 1 This is a schematic diagram of the structure of the flat plate insulator provided in this application;

[0040] Figure 2 This is a schematic diagram of the structure of the post-type insulator provided in this application;

[0041] Figure 3 This is a flowchart of the method for preparing the surface-perforated cavity insulator provided in this application;

[0042] Figure 4 This is a perforated printed topographic image of the cavity insulator of this application;

[0043] Figure 5 These are comparative diagrams showing the surface charge accumulation behavior of Embodiments 1, 8, and Comparative Example 1 of this application;

[0044] List of components and reference numerals:

[0045] 1. Top surface of a flat plate insulator; 2. Through hole of a flat plate insulator; 3. Bottom surface of the cavity of a flat plate insulator; 4. Cavity of a flat plate insulator; 5. Post insulator; 6. Through hole of a post insulator; 7. Bottom surface of the cavity of a post insulator; 8. Cavity of a post insulator. Detailed Implementation

[0046] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0047] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.

[0048] Currently, the two typical structures of insulators include flat plate insulators and post insulators, as shown below: Figure 1 and Figure 2 As shown. Figure 1 This is a schematic diagram of a flat plate insulator. The surface of the flat plate insulator along the electric field is the upper surface 1 of the flat plate insulator. Therefore, multiple through holes 2 of the flat plate insulator are opened on the upper surface 1 of the flat plate insulator, and a cavity 4 of the flat plate insulator is provided inside the flat plate insulator. The surface of the flat plate insulator and at least the bottom surface 3 of the cavity of the flat plate insulator are covered with a thin film with a low secondary electron emission coefficient. Figure 2 This is a schematic diagram of a post-type insulator 5. The surface of the post-type insulator 5 along the electric field is the circumferential surface of the post-type insulator 5. Therefore, multiple through holes 6 of the post-type insulator are opened on the circumferential surface of the post-type insulator 5, and a cavity 8 of the post-type insulator is provided inside the circumferential surface of the post-type insulator. The surface of the post-type insulator and at least the bottom surface 7 of the cavity of the post-type insulator are covered with a thin film with a low secondary electron emission coefficient.

[0049] Regardless of the structure, the insulator involves constructing through-holes and cavities communicating with them on its surface along the electric field. Simultaneously, a thin film with a low secondary electron emission coefficient is deposited on the bottom surface of the cavity. In the following embodiments and comparative examples, the selected 3D printing technology is stereolithography 3D printing, and the coating technology used is magnetron sputtering. Furthermore, the following embodiments and comparative examples use flat insulators with square through-holes arranged in a periodic matrix. The specific process of the 3D-printed insulator fabrication method provided in this application is as follows: Figure 3As shown, a geometric CAD model of an insulator with through holes and cavities is first constructed, and an STL printing file is generated. Then, the insulator is printed using stereolithography 3D printing technology with photocurable resin. After cleaning off excess resin from the printed parts, they are dried. The dried printed parts are then post-cured in a curing chamber. Finally, a coating is applied to the surface of the cured insulator and the bottom of the cavity to obtain an insulator with openings along the electric field surface and cavities inside.

[0050] The photocurable resins used in the following examples and comparative examples are all High Temp type acrylic photocurable resins manufactured by Formlabs.

[0051] Example 1

[0052] This embodiment relates to a 3D-printed insulator, which is prepared using the following steps:

[0053] (1) Design a flat plate insulator with a size of 5cm×5cm square, a thickness of 15mm, a side length W of 1mm for the square through hole, a spacing Q of 0.5mm between adjacent through holes, a depth of 1mm for the through hole, and a cavity depth L of 3mm. Divide the designed CAD model into multiple geometric units and generate an STL file of the model. Use slicing software to convert the STL file into manufacturing data for the 3D printing device.

[0054] (2) Import the model and manufacturing data designed in step (1) into the stereolithography 3D printer, set the single-layer printing thickness to 25 micrometers, the printing temperature to 30°C, use acrylic resin to print the insulator print, and clean the insulator print in an aqueous solution of acetone to remove the attached uncured photopolymer resin. Then dry it in a vacuum oven at 60°C for 2 hours before use.

[0055] (3) The dried insulator printouts from step (2) are placed in a curing chamber for post-curing treatment. The curing light source is 405nm ultraviolet light, the curing temperature is 60℃, and the curing time is 2h to obtain the cured insulators.

[0056] (4) The post-cured insulator is coated in a magnetron sputtering equipment. The target material is chromium oxide and titanium nitride. The sputtering time is 10 minutes and the titanium nitride content is controlled to be 10%. After the coating is completed, the insulator covered with the film is placed in a vacuum oven and dried at 60°C for 2 hours to obtain an insulator with a film covering the surface of the insulator and the bottom of the cavity. The thickness of the film is 100 nm.

[0057] Example 2

[0058] The difference between this embodiment and Embodiment 1 is that the spacing Q between adjacent through holes is 3mm, while the parameters and preparation methods of the other insulators are the same as in Embodiment 1.

[0059] Example 3

[0060] The difference between this embodiment and Embodiment 1 is that the spacing Q between adjacent through holes is 5mm, while the parameters and preparation methods of the other insulators are the same as in Embodiment 1.

[0061] Example 4

[0062] The difference between this embodiment and Embodiment 1 is that the side length W of the square through hole is 0.5 mm, while the parameters and preparation methods of the other insulators are the same as those in Embodiment 1.

[0063] Example 5

[0064] The difference between this embodiment and Embodiment 1 is that the side length W of the square through hole is 5mm, while the parameters and preparation methods of the other insulators are the same as in Embodiment 1.

[0065] Example 6

[0066] The difference between this embodiment and Embodiment 1 is that the cavity depth L of the square through hole is 1 mm, while the parameters and preparation methods of the other insulators are the same as those in Embodiment 1.

[0067] Example 7

[0068] The difference between this embodiment and Embodiment 1 is that the cavity depth L of the square through hole is 10mm, while the parameters and preparation methods of the other insulators are the same as those in Embodiment 1.

[0069] Example 8

[0070] The difference between this embodiment and embodiment 1 is that the surface of the insulator and the bottom surface of the cavity are not coated in step (4), while the parameters and preparation methods of the other insulators are the same as those in embodiment 1.

[0071] Example 9

[0072] The difference between this embodiment and embodiment 1 is that the target material in step (4) is selected as chromium oxide and titanium nitride, and the content of titanium nitride in the film is controlled to be 15%. The parameters and preparation methods of the other insulators are the same as those in embodiment 1.

[0073] Example 10

[0074] The difference between this embodiment and embodiment 1 is that the target material in step (4) is selected as chromium oxide and titanium nitride, and the content of titanium nitride in the film is controlled to be 50%. The parameters and preparation methods of the other insulators are the same as those in embodiment 1.

[0075] Example 11

[0076] The difference between this embodiment and embodiment 1 is that the target material in step (4) is chromium oxide, while the parameters and preparation methods of the other insulators are the same as in embodiment 1.

[0077] Example 12

[0078] The difference between this embodiment and embodiment 1 is that zinc oxide is selected as the target material in step (4), while the parameters and preparation methods of the other insulators are the same as in embodiment 1.

[0079] Example 13

[0080] The difference between this embodiment and embodiment 1 is that the target material in step (4) is titanium nitride, while the parameters and preparation methods of the other insulators are the same as in embodiment 1.

[0081] Example 14

[0082] The difference between this embodiment and Embodiment 1 is that the thickness of the film is 10 nm, while the parameters and preparation methods of the other insulators are the same as in Embodiment 1.

[0083] Example 15

[0084] The difference between this embodiment and Embodiment 1 is that the thickness of the film is 300 nm, while the parameters and preparation methods of the other insulators are the same as in Embodiment 1.

[0085] Example 16

[0086] The difference between this embodiment and Embodiment 1 is that the thickness of the film is 500 nm, while the parameters and preparation methods of the other insulators are the same as in Embodiment 1.

[0087] Example 17

[0088] The difference between this embodiment and Embodiment 1 is that the thickness of the film is 1000 nm, while the parameters and preparation methods of the other insulators are the same as in Embodiment 1.

[0089] Example 18

[0090] The difference between this embodiment and embodiment 1 is that after the coating is completed in step (4), no drying process is performed, and an insulator with a thin film covering the surface of the insulator and the bottom surface of the cavity is directly obtained. The parameters and preparation methods of the other insulators are the same as those in embodiment 1.

[0091] Comparative Example 1

[0092] Comparative Example 1 relates to a single 3D printed smooth insulator with no pores on the surface and no cavities inside. The preparation steps are as follows: the insulator is set to a square with a size of 5cm×5cm and a thickness of 15mm. The CAD model of the design is divided into multiple geometric units and an STL file of the model is generated. The STL file is converted into manufacturing data of the 3D printing device using slicing software. The insulator is printed, cleaned and cured using the same steps (2) and (3) as in Example 1.

[0093] Comparative Example 2

[0094] The difference between Comparative Example 2 and Example 1 is that the insulator model only has through holes and no cavity. The depth of the through holes is the same as in Example 1. In this case, the through holes are blind holes. In Comparative Example 2, the surface of the insulator and the bottom surface of the through holes are also coated. The parameters and preparation methods of the other insulators are the same as in Example 1.

[0095] Test case

[0096] The first surface of the 3D insulator was characterized using scanning electron microscopy, such as... Figure 4 (a) shows the first surface of the insulator in Example 4, with a through-hole side length W = 0.5 mm and a spacing Q = 0.5 mm between adjacent through holes. Figure 4 (b) is the first surface of the insulator of Example 1, with a through hole side length W = 1 mm.

[0097] The surface flashover voltage of the insulators prepared in the above embodiments and comparative examples was tested using a self-built vacuum surface flashover voltage testing system under vacuum impulse voltage. The results are shown in Table 1. The surface charge accumulation behavior of the insulators of Embodiment 1, Embodiment 8, and Comparative Example 1 under different impulse voltages (applied voltage of -30kV) was characterized using a self-built surface charge accumulation behavior device. The surface charge accumulation behavior of Embodiment 1 is shown in Table 1. Figure 5 As shown in (c), the surface charge accumulation behavior of Example 8 is as follows Figure 5 As shown in (b), the surface charge accumulation behavior of Comparative Example 1 is as follows: Figure 5 As shown in (a).

[0098] Table 1

[0099]

[0100]

[0101] Depend on Figure 4The results show that stereolithography 3D printing technology can achieve precise printing of millimeter-level openings. Data from Examples 1-5 in Table 1 shows that the side length and spacing between adjacent through-holes affect the total opening area of ​​all through-holes, thus affecting the number of electrons falling into the cavity and the number of electrons returning to the insulator surface, thereby affecting the flashover voltage increase. The longer the side length of the through-hole (i.e., the larger the opening area) and the shorter the spacing between adjacent through-holes, the more significant the flashover voltage increase; conversely, the shorter the side length of the through-hole (i.e., the smaller the opening area) and the longer the spacing between adjacent through-holes, the worse the flashover voltage increase. Comparing Examples 6 and 7 with Example 1, the cavity depth affects the number of electrons returning to the insulator surface. The shallower the cavity, the worse the flashover voltage increase; the deeper the cavity, the lower the probability of electrons returning to the insulator surface, and the more significant the flashover voltage increase. However, the improvement effect of Example 7 compared to Example 1 is not particularly significant. Considering the mechanical properties of the insulator, setting the cavity depth to 3-5mm is optimal. Comparative Example 2 does not contain a cavity, so electrons enter the through-hole (i.e., blind hole). Since the depth of the through-hole is 1mm, the electrons entering it will escape back to the insulator surface to participate in the subsequent electron multiplication process. Therefore, the electron escape probability of Comparative Example 2 increases, and the improvement effect on flashover voltage is not obvious. According to the test results of Examples 9-13 and Example 1, among the coating materials of chromium oxide and titanium nitride, the improvement effect is best when the titanium nitride content is 15%. Simple chromium oxide, zinc oxide, and titanium nitride will also improve flashover voltage, but the improvement effect is not as good as that of the coating material of chromium oxide and titanium nitride. Moreover, the improvement effect of titanium nitride film on flashover voltage is better than that of chromium oxide. According to the test results of Examples 14-17 and Example 1, the lower the film thickness, the worse the improvement effect on flashover voltage. When the film thickness reaches 300 nm, further increases in film thickness do not significantly improve the flashover voltage. However, excessive film thickness can actually reduce the flashover voltage improvement. This is because excessively thick films tend to block the vias during film formation, reducing the opening area and decreasing the probability of electrons entering the cavity, thus worsening the flashover voltage improvement. Test results from Examples 18 and 1 show that the absence of film drying treatment negatively impacts the flashover voltage improvement of the insulator. Data from Comparative Example 1 and Example 8 show that, compared to insulators without vias, insulators with surface vias and internal cavities exhibit significantly improved flashover voltage. The aging flashover voltage of Example 8 is 74.7% higher than that of Comparative Example 1. Data from Examples 1 and 8 show that after surface coating, the flashover voltage of the insulator in Example 1 is further improved, with the aging voltage of Example 1 increasing by nearly 130% compared to Example 8.

[0102] from Figure 5 It can be seen that the insulators of Examples 1 and 8 exhibit better surface charge accumulation suppression capabilities compared to the insulators without openings and cavities in Comparative Example 1. Furthermore, the ability to suppress surface charge accumulation is further enhanced when the insulator surface and the bottom surface of the cavity are covered with thin films.

[0103] The above description is merely an embodiment of this application, and the scope of protection of this application is not limited to these specific embodiments, but is determined by the claims of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the technical concept and principles of this application should be included within the scope of protection of this application.

Claims

1. An insulator based on 3D printing, characterized in that, The insulator is made of an insulating medium and is prepared by 3D printing. The insulator has multiple through holes on its first surface and a cavity inside the insulator. The multiple through holes are all connected to the cavity. The first surface is a surface along the electric field. The 3D-printed insulator has a surface and at least the bottom surface of the cavity covered with a thin film with a low secondary electron emission coefficient. The thickness of the thin film is 20-1000 nm, and the thin film is selected from any one or more of copper oxide, cobalt oxide, zinc oxide, chromium oxide, and titanium nitride.

2. The 3D-printed insulator according to claim 1, characterized in that, The depth of the cavity is 1~10mm.

3. The 3D-printed insulator according to claim 1, characterized in that, The opening area of ​​the through hole is 0.25 mm. 2 -25mm 2 The spacing between adjacent through holes is 0.5-5mm, and the depth of the through holes is no greater than 5mm.

4. The 3D-printed insulator according to claim 1, characterized in that, The total opening area of ​​the plurality of through holes accounts for 30-80% of the total area of ​​the first surface; and / or The insulator is a flat plate insulator or a post insulator.

5. The method for preparing an insulator based on 3D printing according to any one of claims 1-4, characterized in that, Includes the following steps: (1) Construct a CAD model of the insulator's geometric shape, divide the model into multiple geometric units and generate an STL file of the model, and use slicing software to convert the STL file into manufacturing data for the 3D printing device; (2) The manufacturing data in step (1) is sent to the 3D printing equipment, the insulating medium is used to print the insulator print, and the uncured medium on the surface of the insulator print is cleaned off and then dried. (3) Post-process the insulator print after drying in step (2) to obtain post-processed insulators; (4) Cover the surface of the post-processed insulator and at least the bottom surface of the cavity with a thin film with a low secondary electron emission coefficient, and dry it to obtain the 3D printed insulator.

6. The preparation method according to claim 5, characterized in that, When the insulating medium is a photocurable resin, the post-treatment temperature in step (3) is 20~80℃ and the curing time is 2~5h.

7. The preparation method according to claim 5, characterized in that, The drying process in step (4) involves placing the insulator covered with the film in a vacuum oven and drying it at 30-80°C for 1-5 hours.

8. The application of a 3D-printed insulator according to any one of claims 1-4 or a 3D-printed insulator prepared by the preparation method according to any one of claims 5-7 in insulating components in high-energy particle accelerators, spacecraft, vacuum circuit breakers, pulsed power equipment, and semiconductor manufacturing and processing equipment.

Images