Method of manufacturing a coupler ceramic window assembly

Abstract

The application discloses a manufacturing method of a coupler ceramic window assembly, and relates to the field of coupler ceramic window assembly manufacturing.The manufacturing method comprises the following steps: step 1, positioning and welding a ceramic, a ceramic inner window frame, a ceramic outer window frame and a window water jacket by using a first tooling to obtain a first ceramic window assembly; and step 2, welding an inner conductor vacuum side and an inner conductor atmospheric side to the first ceramic window assembly by using a second tooling to obtain the coupler ceramic window assembly; wherein, DHLAgCuPd28-20 is used as solder for brazing welding in step 1, and electron beam welding is used in step 2.The manufacturing method can solve the problem of ceramic cracking in the welding of the ceramic window assembly, is simple to operate and easy to implement, ensures the vacuum degree and strength after the welding of the ceramic and metal, makes the ceramic window assembly more reliable, and is high in production success rate, short in cycle, and large in production cost saving.

Description

Technical Field

[0001] This invention relates to the field of accelerator technology, and more specifically, to a method for manufacturing a coupler ceramic window assembly. Background Technology

[0002] Couplers are critical components in accelerator systems, serving functions such as vacuum isolation, coupler power transmission, insulation of inner and outer conductors, and matching coupling. The ceramic window is a core component of the coupler. Its primary function is to achieve microwave power transmission through ceramic-metal welding technology. In addition, it must ensure vacuum isolation between the high-vacuum side and the atmospheric side of the coupler, while simultaneously guaranteeing the structural strength of the product.

[0003] As power transmission devices, the quality of the ceramic-metal seal in couplers directly determines whether the coupler can function properly. Therefore, couplers have strict requirements for the seal strength, vacuum leakage rate, and water circuit sealing after ceramic-metal sealing.

[0004] Currently, the manufacturing process for ceramic windows involves two brazing processes, both at temperatures exceeding 800℃. However, during the second brazing, the ceramic material in the window is highly susceptible to cracking under the stress generated during the welding process, making it difficult to guarantee a tight seal and maintain the window's integrity. Summary of the Invention

[0005] The purpose of this invention is to provide a method for manufacturing a coupler ceramic window assembly. This method can solve the problem of ceramic breakage during the welding of ceramic window assemblies. It is simple to operate and easy to implement, ensuring the vacuum degree and strength after the ceramic and metal are welded, making the ceramic window assembly more reliable. At the same time, it has a high production success rate, short cycle, and saves a lot of production costs.

[0006] To achieve the above objectives, the present invention provides a method for manufacturing a coupler ceramic window assembly, the method comprising:

[0007] Step 1: Use the first tooling to position and weld the ceramic, the inner ceramic window frame, the outer ceramic window frame, and the window water jacket to obtain the first ceramic window assembly;

[0008] Step 2: Using the second tooling, weld the vacuum side and atmospheric side of the inner conductor to the first ceramic window assembly to obtain the coupler ceramic window assembly; wherein,

[0009] In step 1, DHLAgCuPd28-20 was used as the solder for brazing, and in step 2, electron beam welding was used.

[0010] Preferably, the first tooling is configured to simultaneously position the ceramic, the inner ceramic window frame, the outer ceramic window frame, and the window water jacket.

[0011] Preferably, the second tooling is configured to simultaneously position the vacuum side of the inner conductor, the atmospheric side of the inner conductor, and the water pipe.

[0012] Preferably, the metal parts are degreased and pickled before welding in step 1, and then assembled after drying.

[0013] Preferably, in step 1, the ceramic and the inner ceramic window frame are welded with 0.05mm thick DHLAgCuPd28-20 solder sheet, the ceramic and the outer ceramic window frame are welded with 0.5mm diameter DHLAgCuPd28-20 solder wire, and the remaining welds are welded with 0.8mm diameter DHLAgCuPd28-20 solder wire.

[0014] Preferably, a vacuum furnace is used for brazing in step 1.

[0015] Preferably, the metal parts are degreased and pickled before welding in step 2.

[0016] Preferably, aluminum foil is used to cover the ceramic surface of the first ceramic window assembly during welding in step 2.

[0017] According to the above technical solution, this invention performs only one brazing operation to reduce the thermal shock to the ceramic during brazing. The structure involves the ceramic, as an insulating material, being brazed to the inner and outer conductors of the ceramic window in the first step, using DHLAgCuPd28-20 solder. Then, the brazed first ceramic window assembly is electron-beam welded to the vacuum side and atmospheric side of the inner conductor to ensure watertightness after welding. Thus, the ceramic window assembly is manufactured through one step of brazing and one step of electron-beam welding.

[0018] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0020] Figure 1 This is a schematic diagram of the structure of the first ceramic window assembly in this invention;

[0021] Figure 2 This is a welding schematic diagram of the first ceramic window assembly in this invention;

[0022] Figure 3 This is a schematic diagram of the structure of the coupler ceramic window assembly in this invention;

[0023] Figure 4 This is a schematic diagram of the welding of the coupler ceramic window assembly in this invention. Detailed Implementation

[0024] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0025] In this invention, unless otherwise stated, directional terms such as "inner" and "outer" in the terminology represent only the orientation of the term in its normal use or are common terms understood by those skilled in the art, and should not be regarded as limitations on the term.

[0026] See Figures 1 to 4 The present invention provides a method for manufacturing a coupler ceramic window assembly, the method comprising:

[0027] Step 1: Use the first tooling to position and weld the ceramic, the inner ceramic window frame, the outer ceramic window frame, and the window water jacket to obtain the first ceramic window assembly;

[0028] Step 2: Using the second tooling, weld the vacuum side and atmospheric side of the inner conductor to the first ceramic window assembly to obtain the coupler ceramic window assembly; wherein,

[0029] In step 1, DHLAgCuPd28-20 was used as the solder for brazing, and in step 2, electron beam welding was used.

[0030] In the above-mentioned tooling positioning process, in order to improve the stability after positioning and ensure the welding effect, preferably, the first tooling is configured to simultaneously position the ceramic, the inner ceramic window frame, the outer ceramic window frame, and the window water jacket.

[0031] Similarly, the second tooling is preferably configured to simultaneously position the vacuum side of the inner conductor, the atmospheric side of the inner conductor, and the water pipe.

[0032] Before welding in step 1, the metal parts are degreased and pickled, and then assembled after drying.

[0033] In addition, in step 1, the ceramic and the inner ceramic window frame are welded with 0.05mm thick DHLAgCuPd28-20 solder sheet, the ceramic and the outer ceramic window frame are welded with 0.5mm diameter DHLAgCuPd28-20 solder wire, and the remaining welds are welded with 0.8mm diameter DHLAgCuPd28-20 solder wire.

[0034] Furthermore, brazing is performed using a vacuum furnace in step 1.

[0035] In addition, the metal parts are degreased and pickled before welding in step 2 to ensure hygiene during electron beam welding. Simultaneously, aluminum foil is used to shield the ceramic surface of the first ceramic window assembly during welding in step 2 to prevent contamination. The assembled assembly needs to be inspected for weld uniformity.

[0036] In practical operation, since silicon carbide ceramics cannot be directly welded to metals, the basic welding methods are metallization and reactive welding. Metallization involves coating (or pasting) metal powder onto the ceramic area to be welded, then calcining it in a furnace to melt and wet the ceramic surface. A second calcination with solder is then performed to weld the ceramic and metal together. The disadvantages of metallization are its cumbersome operation, numerous steps, and long production cycle. Therefore, this method adopts reactive welding, which has the advantages of simple operation, requiring only one sintering, and avoiding the tensile stress caused by the molten solder during the second sintering and cooling, which could lead to ceramic cracking. The operation steps are as follows:

[0037] After the titanium powder is mixed evenly with the nitrocellulose solution, it is evenly coated onto the surface of silicon carbide that needs to be welded, so that the titanium element penetrates into the interior of silicon carbide (the interior of silicon carbide has many tiny pores). After coating, it is dried.

[0038] In step 1, the solder used for welding is DHLAgCuPd28-20, and the welding temperature is approximately 900℃. This solder is suitable for welding ceramics and oxygen-free copper. The welding process for oxygen-free copper and stainless steel is already well-established. At a reference temperature of 800℃, the coefficient of thermal expansion of the ceramic is 6.80 × 10⁻⁶. -3 The coefficient of thermal expansion of oxygen-free copper is 1.55 × 10 mm / ℃. -2 The difference between mm / ℃ and the two is significant. During high-temperature welding, both oxygen-free copper and ceramic expand simultaneously. Due to the large coefficient of expansion of oxygen-free copper, its expansion is substantial. This results in an excessively large gap between the oxygen-free copper and ceramic, causing the solder to fail to fill the weld and leading to air leakage. Because oxygen-free copper has good plasticity, its outer wall can be bound with a metal with a low coefficient of expansion to achieve the welding purpose.

[0039] In summary, the production and manufacturing process of this invention is simpler and easier to implement than other methods, with a high success rate and short cycle time. Furthermore, the first and second tooling used in the manufacturing process can be reused, and only one brazing step is required, saving significant production costs. The coupler ceramic window assembly manufactured by this method combines the physical and chemical properties of the materials, and the ingenious tooling design ensures the vacuum level and strength after the ceramic and metal are welded, making the ceramic window assembly more reliable.

[0040] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0041] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0042] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method of manufacturing a coupler ceramic window assembly, characterized by, The manufacturing method comprises: Step 1, positioning and welding the ceramic, the ceramic inner window frame, the ceramic outer window frame and the window water jacket using a first tooling to obtain a first ceramic window assembly; Step 2, welding the inner conductor vacuum side and the inner conductor atmospheric side to the first ceramic window assembly using a second tooling to obtain a coupler ceramic window assembly; wherein, DHLAgCuPd28-20 is used as the solder for brazing in Step 1, and electron beam welding is used in Step 2.

2. The method of manufacturing a coupler ceramic window assembly of claim 1, wherein, The first tooling is configured to simultaneously position the ceramic, the ceramic inner window frame, the ceramic outer window frame and the window water jacket.

3. The method of manufacturing a coupler ceramic window assembly of claim 1, wherein, The second tooling is configured to simultaneously position the inner conductor vacuum side, the inner conductor atmospheric side and the water pipe.

4. The method of manufacturing a coupler ceramic window assembly of claim 1, wherein, The metal parts are degreased and pickled before Step 1.

5. The method of manufacturing a coupler ceramic window assembly of claim 1, wherein, In Step 1, the ceramic and the ceramic inner window frame are welded using a 0.05mm-thick DHLAgCuPd28-20 solder sheet, the ceramic and the ceramic outer window frame are welded using a 0.5mm-diameter DHLAgCuPd28-20 solder wire, and the remaining welds are welded using a 0.8mm-diameter DHLAgCuPd28-20 solder wire.

6. The method of manufacturing a coupler ceramic window assembly of claim 5, wherein, Vacuum furnace is used for brazing in Step 1.

7. The method of manufacturing a coupler ceramic window assembly of claim 1, wherein, The metal parts are degreased and pickled before Step 2.

8. The method of claim 1, wherein Aluminum foil is used to shield the ceramic surface in the first ceramic window assembly during welding in Step 2.

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