PEEK vacuum chamber structure embedded with metal flange and manufacturing method thereof

Abstract

The application relates to a PEEK vacuum chamber structure embedded with a metal flange and a manufacturing method, wherein the PEEK vacuum chamber structure embedded with the metal flange comprises a PEEK vacuum chamber embedded with a metal flange, a first metal flange and a second metal flange located at two ends of a PEEK vacuum chamber body, and a metal flange back plate arranged at the two ends of the PEEK vacuum chamber body; and an area-expanding guide component is arranged at a contact position of the first metal flange and the second metal flange with the PEEK vacuum chamber body. The application replaces the PEEK flange with the metal flange by utilizing the characteristics that stainless steel and PEEK have strong binding force at high temperature, and realizes the manufacturing of the structure based on a mold pressing process, so that the problems that the PEEK flange structure is insufficient in strength, the sealing surface is low in hardness and reliable sealing is difficult to realize are solved.

Description

Technical Field

[0001] This invention relates to a PEEK vacuum chamber structure and manufacturing method with an embedded metal flange, belonging to the field of low eddy current vacuum cavity manufacturing technology in fast-cycle particle accelerators. Background Technology

[0002] Particle accelerators are continuously developing towards higher repetition rates, aiming to provide experimental platforms with higher energies, higher currents, and stronger beams for cutting-edge research in multiple disciplines such as nuclear physics, atomic physics, high-energy-density physics, neutron science, meson physics, and life sciences. However, with the increase in repetition rate, the eddy current effect induced by the high-frequency magnetic field on the vacuum tube wall has become a key bottleneck restricting the improvement of accelerator performance. When the repetition rate reaches 200 Hz or higher, it is usually necessary to use insulating materials to make the magnetic vacuum chamber to effectively suppress the eddy current effect. The current mainstream solution is to use alumina ceramic vacuum chambers, but it has problems such as low sintering yield, difficult brazing process, poor structural stability under high-temperature baking conditions, and fragility during transportation and installation, and its engineering reliability still needs to be improved. Polyetheretherketone (PEEK), due to its excellent mechanical strength, heat resistance, chemical stability, and good radiation resistance, is expected to replace ceramics as the main material for the next generation of magnetic component vacuum chambers.

[0003] However, the flanges of the 30% CF vacuum chambers made entirely of PEEK using injection molding and extrusion processes are also made of PEEK material. In actual sealing processes, PEEK flanges present significant problems: if silver wire seals are used, the bolt preload can easily cause flange cracking, and the silver wire seal can also undergo plastic deformation due to excessive preload; if rubber O-ring seals are used, the rubber surface has poor gas venting rate and is not heat-resistant, affecting the achievement of the chamber's ultimate vacuum; if metal C-ring seals are used, although a sealing effect can be achieved, leakage is very likely during baking, and C-rings are extremely expensive, resulting in insufficient engineering reliability and economy. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a PEEK vacuum chamber structure and manufacturing method with an embedded metal flange. It utilizes the strong bonding properties of stainless steel and PEEK at high temperatures to replace the PEEK flange with a metal flange, and manufactures the structure based on a molding process. This solves the problems of insufficient structural strength and low hardness of the sealing surface of PEEK flanges, which make it difficult to achieve reliable sealing.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A PEEK vacuum chamber structure with an embedded metal flange includes: A PEEK vacuum chamber with embedded metal flanges includes a PEEK vacuum chamber body and a first metal flange and a second metal flange located at both ends of the PEEK vacuum chamber body. Metal flange back plates are also provided at both ends of the PEEK vacuum chamber body. The first metal flange and the second metal flange are provided with enlarged guide members at the contact positions with the PEEK vacuum chamber body.

[0006] Preferably, in the PEEK vacuum chamber structure with embedded metal flange, the expanded guide member includes any one of arc-shaped protrusions, chamfers, or grooves.

[0007] A second aspect of the present invention provides a method for manufacturing a PEEK vacuum chamber structure with an embedded metal flange, comprising the following steps: Step 1: Machining of Metal Flanges and Flange Back Plates: According to the design drawings, using an advanced five-axis machining center, the blank parts are clamped and then machined sequentially using turning, drilling, and precision milling. Note that a machining allowance should be left on the flange end face to prevent damage to the sealing surface during subsequent molding and demolding processes, which could result in the flange's mechanical dimensions failing to meet requirements.

[0008] Step 2: Post-treatment of the metal flange inner cavity: To ensure sufficient contact area between the PEEK vacuum chamber body 5 and the metal flange, and to ensure the connection between the PEEK vacuum chamber body 5 and the metal flange is as stable as possible, a dry sandblasting process is first adopted. Hard abrasives (such as diamond) with a particle size of 220-300μm are selected, and the inner cavity surface of the metal flange is uniformly blasted for 2-3 minutes at a high sandblasting pressure of 0.7-0.9MPa, a close distance of 90-120mm, and a 90° vertical angle. After sandblasting, ultrasonic cleaning is required to thoroughly remove residual abrasives and oil stains from the surface to ensure an ideal mechanical anchoring structure. Further, a traditional chemical etching process is adopted, using a solution prepared from FeCl3, HCl, and H2O2 in a certain volume ratio, to chemically etch the inner cavity surface of the metal flange for 5-15 minutes at room temperature, forming a micron-level rough structure. Subsequently, electrochemical etching was performed using an electrolyte composed of HCl and HNO3 at a DC voltage of 10-15V (two-electrode system), with the processing temperature controlled at 20-40℃ for approximately 10-15 minutes, thereby forming a uniform nanoscale porous structure on the inner surface of the metal flange. After the two-step processing, ultrasonic cleaning with deionized water and drying were performed to obtain a micron-nano composite rough interface, providing a reliable anchoring structure for the subsequent high-strength bonding between the PEEK vacuum chamber body 5 and the metal flange. In addition, to further enhance the bonding between the PEEK vacuum chamber body 5 and the metal flange and reduce the risk of delamination during molding due to the difference in thermal expansion coefficients between the PEEK vacuum chamber body 5 and the metal flange, a nanoscale Ti film was further deposited in the inner cavity of the metal flange using a DC magnetron sputtering process. The deposition process parameters are as follows: working gas Ar flow rate 110–200 sccm, deposition pressure 0.2–0.5 Pa, deposition temperature 120–180°C, deposition current 10–15 A, deposition time 10–20 min, and substrate bias 50–80 V.

[0009] Step 3: Integrated Molding: Before molding, a friction-reducing layer needs to be applied to the inner and outer cores of the mold that come into contact with the PEEK vacuum chamber body 5 to facilitate smooth demolding later. Specifically, the inner core is made of mold steel (model H13 / 8407 / 2344). First, a layer of graphite is coated onto the inner core, followed by 2-3 layers of 5-micron thick polyimide film. This polyimide film must be able to withstand temperatures above 380℃ to prevent it from melting and adhering to the inner wall of the PEEK vacuum chamber body 5 during heating. The polyimide film also serves to prevent molten PEEK from flowing out from the parting line of the inner core. Similarly, the outer core of the PEEK vacuum chamber body 5 also needs to be coated with a graphite friction-reducing layer. After preparation, the PEEK raw material is dried (180-220℃, 2-6 hours) to ensure no moisture is present, preventing bubbles or other defects from appearing during the molding process of the PEEK vacuum chamber body 5. Next, the weighed PEEK raw material is loaded into the mold, and then the mold is closed. Further still, the entire mold is heated to 370~390℃ at a heating rate of 3~8℃ / min. After reaching the target temperature, pressure is applied to 8~12MPa, and the temperature and pressure are maintained for 40~60min to allow the PEEK to flow fully and fill the cavity. Further still, after the heat treatment, the mold is slowly cooled at a rate of 1~2℃ / min to prevent internal stress, warping, or cracking of the PEEK vacuum chamber body 5 due to excessive temperature difference, and to prevent the PEEK vacuum chamber body 5 from detaching from the metal flange. Further still, once the mold has cooled to below 140℃, the outer mold core is demolded first. After the outer mold core is completely removed, the inner mold core also needs to be demolded. Furthermore, the demolded PEEK vacuum chamber body 5 is annealed at a temperature of 150~200℃ for about 1 hour to eliminate residual stress generated inside the PEEK vacuum chamber during the molding process and improve dimensional stability and mechanical properties.

[0010] Step 4: Finishing: Using traditional machining methods (turning, milling, grinding, mechanical polishing, etc.), the inner and outer surfaces of the PEEK vacuum chamber body 5 are machined according to the dimensions required by the drawings, and the metal flange end face is precision machined to ensure that the roughness is less than 1.6.

[0011] Step 5: Ultra-high vacuum cleaning: rough cleaning to remove visible dirt → 65 Ultrasonic cleaning in a weakly acidic aqueous solution for approximately 15 minutes to remove oil → immerse in 65... In a weakly alkaline solution (C), ultrasonically clean for about 15 minutes to neutralize, then rinse repeatedly with flowing deionized water until no foam remains, and finally blow dry with high-purity nitrogen.

[0012] Step 6: X-ray inspection: The internal structure of the PEEK vacuum chamber body 5 is inspected using X-ray to avoid internal defects that could lead to insufficient structural strength in the final product.

[0013] Step 7: Vacuum Leak Detection: Use helium mass spectrometry to detect leaks at the metal flange sealing surface, the contact point between the metal flange and the PEEK vacuum chamber body 5, and the PEEK vacuum chamber body 5 itself. The leak rate should be less than 1×10⁻⁶. - 8 Pa.ls -1 Then it is considered qualified.

[0014] Step 8: Dimensional Inspection: Use a laser tracker (model: Leica AT 960) to measure the width, height, flatness, and perpendicularity of the flange face to the axis of the cross-section. All mechanical dimensions should be within ±0.5mm.

[0015] The present invention has the following advantages due to the adoption of the above technical solutions: The PEEK vacuum chamber structure with embedded metal flange provided by this invention effectively solves several problems caused by the insufficient strength and hardness of pure PEEK flanges, including: flange cracking caused by bolt preload; difficulty in improving the ultimate vacuum level when using rubber sealing rings; the complete scrapping of the vacuum chamber due to plastic deformation at the contact point between the silver wire and the PEEK flange when using silver wire seals; easy leakage during vacuum baking when using C-type sealing rings; and the high cost of using C-type sealing rings. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a PEEK vacuum chamber structure with an embedded metal flange provided in an embodiment of the present invention; Figure 2 This is a detailed view of the metal flange provided in this embodiment of the present invention; The attached figures are labeled as follows: 1- PEEK vacuum chamber with embedded metal flange; 2- First metal flange; 3- Back plate of first metal flange; 4- Back plate of second metal flange; 5- Main body of PEEK vacuum chamber; 6- Back plate of third metal flange; 7- Back plate of fourth metal flange; 8- Second metal flange. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention are described clearly and completely below. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0018] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," "third," "fourth," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0019] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "above," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure.

[0020] Currently, vacuum chambers made entirely of PEEK 30% CF using injection molding and extrusion processes also have flanges made of PEEK material. However, PEEK flanges present significant problems during actual sealing: if silver wire seals are used, the bolt preload can easily cause flange cracking, and the silver wire seal can also undergo plastic deformation due to excessive preload; if rubber O-ring seals are used, the rubber surface has poor gas venting rate and is not heat-resistant, affecting the achievement of ultimate vacuum in the chamber; if metal C-ring seals are used, although a sealing effect can be achieved, leakage is highly likely during baking, and C-rings are extremely expensive, resulting in insufficient engineering reliability and economy.

[0021] To address the aforementioned technical problems, this invention provides a PEEK vacuum chamber structure and manufacturing method with an embedded metal flange. It utilizes the strong bonding properties of stainless steel and PEEK at high temperatures to replace the PEEK flange with a metal flange and manufactures the structure using a molding process. This solves the problems of insufficient structural strength and low hardness of the sealing surface of PEEK flanges, which make it difficult to achieve reliable sealing.

[0022] like Figure 1 , 2As shown, the PEEK vacuum chamber structure with embedded metal flanges involved in this invention includes: a PEEK vacuum chamber 1 with embedded metal flanges, a PEEK vacuum chamber body 5 with a racetrack-shaped cross section, a first metal flange 2 and a second metal flange 8 located at both ends of the PEEK vacuum chamber body 5 and easily molded, and a first metal flange back plate 3, a second metal flange back plate 4, a third metal flange back plate 6 and a fourth metal flange back plate 7 for strengthening subsequent sealing.

[0023] The first metal flange 2 and the second metal flange 8 have specific structures (such as raised arc structures, chamfers, and grooves) designed at their contact points with the PEEK vacuum chamber body 5. These structures aim to ensure sufficient contact area between the PEEK vacuum chamber body 5 and the metal flanges, and to ensure that shrinkage during the cooling and shaping stage of the molding process occurs in a specific direction. It is worth noting that the flatness and roughness of the sealing surfaces of the first metal flange 2 and the second metal flange 8 should be as good as possible to ensure reliable sealing in the later stages. The detailed structure of the first metal flange 2 and the second metal flange 8 is as follows... Figure 2 As shown.

[0024] A second aspect of the present invention provides a method for manufacturing a PEEK vacuum chamber structure with an embedded metal flange, comprising the following specific steps: Step 1: Machining of Metal Flanges and Flange Back Plates: According to the design drawings, the first metal flange 2, the second metal flange 8, the first metal flange back plate 3, the second metal flange back plate 4, the third metal flange back plate 6, and the fourth metal flange back plate 7 are machined using an advanced five-axis machining center. The machining steps include blank clamping, turning, drilling, and precision milling. Note that a machining allowance should be left on the flange end face to prevent damage to the sealing surface during subsequent molding and demolding processes, which could result in the flange's mechanical dimensions not meeting requirements.

[0025] Step 2: Post-treatment of the metal flange inner cavity: To ensure sufficient contact area between the PEEK vacuum chamber body 5 and the metal flange, and to ensure the connection between the PEEK vacuum chamber body 5 and the metal flange is as stable as possible, a dry sandblasting process is first adopted. Hard abrasives (such as diamond) with a particle size of 280μm are selected, and the inner surface of the metal flange is uniformly blasted for 3 minutes at a high sandblasting pressure of 0.8MPa, a close distance of 90mm, and a 90° vertical angle. After sandblasting, ultrasonic cleaning is required to thoroughly remove residual abrasives and oil stains from the surface to ensure an ideal mechanical anchoring structure. Further, a traditional chemical etching process is adopted, using a solution prepared from FeCl3, HCl, and H2O2 in a volume ratio of 15:1:1, to chemically etch the inner surface of the metal flange for 5 minutes at room temperature, forming a micron-level rough structure. Subsequently, electrochemical etching was performed at a DC voltage of 12V (two-electrode system) using an electrolyte composed of 4.0% HCl and 1.3% HNO3 by volume, with the processing temperature controlled at 30°C and the time approximately 15 minutes. This resulted in the formation of a uniform nanoscale porous structure on the inner surface of the metal flange. After two-step processing, the surface was ultrasonically cleaned with deionized water and dried to obtain a micron-nano composite rough interface, providing a reliable anchoring structure for the subsequent high-strength bonding between the PEEK vacuum chamber body 5 and the metal flange. Furthermore, to further enhance the bonding between the PEEK vacuum chamber body 5 and the metal flange, and to reduce the risk of delamination during molding due to the difference in thermal expansion coefficients between the two, a DC magnetron sputtering process was used to deposit nanoscale Ti films in the inner cavities of the first metal flange 2 and the second metal flange 8. The deposition process parameters were: Ar working gas flow rate 120 sccm, deposition pressure 0.25 Pa, deposition temperature 160°C, deposition current 12 A, deposition time 15 min, and substrate bias voltage 80V.

[0026] Step 3: Integrated Molding: Before molding, a friction-reducing layer needs to be applied to the inner and outer cores of the mold that come into contact with the PEEK vacuum chamber body 5 to facilitate smooth demolding later. Specifically, the inner core is made of H13 mold steel. First, a layer of graphite is coated onto the inner core, followed by two 5-micron-thick layers of polyimide film. This polyimide film must be able to withstand temperatures above 380°C to prevent it from melting and adhering to the inner wall of the PEEK vacuum chamber body 5 during heating. The polyimide film also serves to prevent molten PEEK from flowing out from the parting line of the inner core. Similarly, the outer core of the PEEK vacuum chamber body 5 also needs to be coated with a graphite friction-reducing layer. After preparation, the PEEK raw material is dried at 200°C for 3 hours to ensure no moisture is present, preventing bubbles or other defects from appearing in the PEEK vacuum chamber body 5 during molding. Finally, the weighed PEEK raw material is loaded into the mold, and then the mold is closed. Furthermore, the entire mold is heated to 370℃ at a heating rate of 3℃ / min. After reaching the target temperature, it is pressurized to 10MPa and held at that temperature and pressure for 60 minutes to allow the PEEK to flow fully and fill the cavity. Further, after the holding period, it is slowly cooled at a rate of 1℃ / min to prevent internal stress, warping, or cracking of the PEEK vacuum chamber body 5 due to excessive temperature differences, and to prevent the PEEK vacuum chamber body 5 from detaching from the metal flange contact point. Further, once the mold has cooled to below 140℃, the outer mold core is demolded first. After the outer mold core is completely removed, the inner mold core is also demolded. Further, the demolded PEEK vacuum chamber body 5 is annealed at 180℃ for approximately 1 hour to eliminate residual stress generated during the molding process and improve dimensional stability and mechanical properties.

[0027] Step 4: Finishing: Using traditional machining methods (turning, milling, grinding, mechanical polishing, etc.), the inner and outer surfaces of the PEEK vacuum chamber body 5 are machined according to the dimensions required by the drawings, and the metal flange end face is precision machined to ensure that the roughness is less than 1.6.

[0028] Step 5: Ultra-high vacuum cleaning: rough cleaning to remove visible dirt → 65 Ultrasonic cleaning in a weakly acidic aqueous solution for approximately 15 minutes to remove oil → immerse in 65... In a weakly alkaline solution (C), ultrasonically clean for about 15 minutes to neutralize, then rinse repeatedly with flowing deionized water until no foam remains, and finally blow dry with high-purity nitrogen.

[0029] Step 6: X-ray inspection: The internal structure of the PEEK vacuum chamber body 5 is inspected using X-ray to avoid internal defects that could lead to insufficient structural strength in the final product.

[0030] Step 7: Vacuum Leak Detection: Use helium mass spectrometry to detect leaks at the metal flange sealing surface, the contact point between the metal flange and the PEEK vacuum chamber body 5, and the PEEK vacuum chamber body 5 itself. The leak rate should be less than 1×10⁻⁶. - 8 Pa.ls -1 Then it is considered qualified.

[0031] Step 8: Dimensional Inspection: Use a laser tracker (model: Leica AT 960) to measure the width, height, flatness, and perpendicularity of the flange face to the axis of the cross-section. All mechanical dimensions should be within ±0.5 mm.

[0032] The PEEK vacuum chamber structure with embedded metal flange provided by this invention effectively solves several problems caused by the insufficient strength and hardness of pure PEEK flanges, including: flange cracking under bolt preload; difficulty in improving the ultimate vacuum level when using rubber sealing rings; the complete failure of the vacuum chamber due to plastic deformation at the contact point between the silver wire and the PEEK flange when using silver wire seals; leakage during vacuum baking when using C-type sealing rings; and the high cost associated with using C-type sealing rings. Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A PEEK vacuum chamber structure with an embedded metal flange, characterized in that, include: The PEEK vacuum chamber (1) with embedded metal flanges includes a PEEK vacuum chamber body (5) and a first metal flange (2) and a second metal flange (8) located at both ends of the PEEK vacuum chamber body (5). Metal flange back plates are also provided at both ends of the PEEK vacuum chamber body (5). The first metal flange (2) and the second metal flange (8) are provided with enlarged guide members at the contact positions with the PEEK vacuum chamber body (5); The method for fabricating the PEEK vacuum chamber structure includes the following steps: Step 1: After clamping the blank, perform machining processes including turning, drilling and precision milling in sequence to obtain the metal flange and the metal flange back plate. Step 2: First, a dry sandblasting process is used, where hard abrasive is uniformly sprayed onto the inner surface of the metal flange under certain sandblasting pressure, distance, and angle. After sandblasting, the inner surface of the metal flange is ultrasonically cleaned. Then, a chemical etching process is used, where an etching solution is used to chemically etch the inner surface of the metal flange. Subsequently, electrochemical etching is performed using an electrolyte under a certain voltage. After electrochemical etching, the inner surface of the metal flange is ultrasonically cleaned with deionized water and dried to obtain a micron-nano composite rough interface. In Step 2, the particle size of the hard abrasive is 220-300μm, the sandblasting pressure is 0.7-0.9MPa, the sandblasting distance is 90-120mm, the sandblasting angle is 90° vertical, and the sandblasting time is 2-3 minutes. Step 3: Lay a friction-reducing layer on the inner core and outer core of the mold that are in contact with the PEEK vacuum chamber body (5), then dry the PEEK raw material and put it into the mold. Heat the mold to the target temperature and pressurize it to a certain pressure. Keep the temperature and pressure to allow the PEEK to flow fully and fill the cavity. After the heat preservation is completed, cool it at a certain cooling rate. After cooling to a certain temperature, demold to obtain the PEEK vacuum chamber body (5). Step 4: The inner and outer surfaces of the PEEK vacuum chamber body (5) are machined according to the dimensions required in the drawings using mechanical processing methods, and the end face of the metal flange is precision machined to ensure that the roughness is less than 1.

6. Step 5: After rough cleaning the PEEK vacuum chamber body (5) obtained in step 4 to remove visible dirt, place it in a weakly acidic water-based solution at a certain temperature for ultrasonic cleaning to remove oil. Then place it in a weakly alkaline solution at a certain temperature for ultrasonic cleaning to neutralize the weakly acidic water-based solution. Finally, rinse it repeatedly with flowing deionized water until there is no foam, and then blow dry the water stains with inert gas. Step 6: The internal structure of the PEEK vacuum chamber body (5) obtained in Step 5 is inspected using X-ray; Step 7: Use helium mass spectrometry to perform vacuum leak detection on the sealing surface of the metal flange, the contact position between the metal flange and the PEEK vacuum chamber body (5), and the PEEK vacuum chamber body (5) itself; Step 8: Use a laser tracker to measure the width, height, flatness, and perpendicularity of the flange face to the axis of the metal flange section to ensure that the metal flange has the required dimensions.

2. The PEEK vacuum chamber structure with an embedded metal flange according to claim 1, characterized in that, The expanded guide component includes any one of the following: an arc-shaped protrusion, a chamfer, or a groove.

3. The PEEK vacuum chamber structure with an embedded metal flange according to claim 1, characterized in that, In step 2, the etching solution is a FeCl3, HCl and H2O2 solution with a volume ratio of 15:1:

1.

4. The PEEK vacuum chamber structure with an embedded metal flange according to claim 1, characterized in that, In step 2, the electrolyte is a solution of 4.0% HCl and 1.3% HNO3 by volume. The electrolysis is carried out at a DC voltage of 10-15V, an electrolysis temperature of 20-40℃, and a time of 10-15 minutes.

5. The PEEK vacuum chamber structure with an embedded metal flange according to claim 1, characterized in that, Step 2 also includes the following steps: A nanoscale Ti film was deposited on the micron-nano composite rough interface inside the metal flange cavity using DC magnetron sputtering. The deposition process parameters were as follows: working gas Ar flow rate 110–200 sccm, deposition pressure 0.2–0.5 Pa, deposition temperature 120–180°C, deposition current 10–15 A, deposition time 10–20 min, and substrate bias 50–80 V.

6. The PEEK vacuum chamber structure with an embedded metal flange according to claim 1, characterized in that, In step 3, a friction-reducing layer is laid on the inner core and outer core of the mold that are in contact with the PEEK vacuum chamber body (5). The specific steps are as follows: First, a layer of graphite is coated on the inner core of the mold, and then 2 to 3 layers of 5-micron thick polyimide film are wrapped around it. A graphite anti-friction layer is also coated on the outer core of the mold.

7. The PEEK vacuum chamber structure with an embedded metal flange according to claim 1, characterized in that, In step 3, the PEEK vacuum chamber body (5) obtained by demolding is annealed at a temperature of 150~200℃ for 1-2 hours.

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