Device and method for forming cathode filament of space electron beam welding gun

Abstract

The invention relates to a cathode filament forming device and method for a space electron beam welding gun. The cathode filament forming device comprises a pressure sensor, an extrusion column, a supporting frame, a pressing head guide rail column, a cathode filament forming pressing head, a cathode filament forming positioning groove, a cathode filament forming mold and a fixing pin. According to the device and the method for forming the cathode filament of the space electron beam welding gun, the requirement of the cathode filament of the space electron beam welding gun can be simply and quickly met, and the device and the method can be popularized and applied to the field of space station electron beam processing; the device system is simple, the forming method is convenient in process, multi-specification simultaneous forming and single-specification batch forming of the cathode filaments can be achieved, the device with the pressure capable of being accurately controlled is formed, and the requirement for multifunctional application of a space electron beam welding gun is effectively met; the cathode filament of the space electron beam welding gun is prepared through the method, a finished product which is good in shape control design, high in precision, small in plastic deformation and good in comprehensive performance can be obtained, and the quality of beam spots can be guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of aerospace material processing, and more specifically, to a cathode filament forming device and method for a space electron beam welding gun. Background Art

[0002] The cathode filament forming technology in the prior art is mainly used for ground electron beam welding guns. The cathode filament for ground electron beams relies on stamping and forming, and the emission surface quality is poor, resulting in poor beam spot quality. The electron beam often requires a higher power supply, which results in a larger power supply equipment, causing greater damage to the cathode and anode of the electron beam welding gun. The filament formed by stamping is prone to breakage at the connection between the filament clamping end and the beam emission surface end, and has a short life. Therefore, it is not suitable for electron beam welding devices in space environments.

[0003] The space electron beam welding gun is a miniaturized, lightweight, low-voltage welding gun that uses electron beam as a heat source. It is mainly used for the assembly and maintenance of space station components. This type of electron gun is mainly composed of a cathode assembly and an anode assembly. The cathode filament in the cathode assembly is the main carrier of the electron beam emission. Therefore, the cathode filament material selection and molding design have an important impact on the electrostatic system of the electron gun. At present, the commonly used cathode filament materials on the ground are tungsten, lanthanum hexaboride and persimmon hexaboride. Among them, the filament materials used in electron beam welding guns are mainly concentrated in tungsten.

[0004] In the development process of space electron beam welding gun, cathode filament shaping design is crucial. The shape and size of this component have a great influence on the emission and beam quality of the electron gun beam. In order to improve the beam emission intensity and beam quality under low pressure conditions, the cathode filament shaping device and method of space electron beam welding gun are indispensable. Summary of the invention

[0005] The embodiments of the present application provide a cathode filament forming device and method for a space electron beam welding gun. In order to have a basic understanding of some aspects of the disclosed embodiments, a simple summary is given below. This summary is not a general review, nor is it intended to identify key / important components or describe the scope of protection of these embodiments. Its only purpose is to present some concepts in a simple form as a preface to the detailed description that follows.

[0006] In a first aspect, an embodiment of the present application provides a cathode filament forming device for a space electron beam welding gun, the device comprising: a pressure sensor, an extrusion column, a support frame, a pressure head guide column, a cathode filament forming pressure head, a cathode filament forming positioning groove, a cathode filament forming mold and a fixing pin, wherein:

[0007] The extrusion column is connected to the pressure sensor to form a pressure sensing system;

[0008] The extrusion column is fixedly connected to the cathode filament forming press head, and the cathode filament forming press head is pushed by the extrusion column to extrude the filament sheet;

[0009] The cathode filament forming press head and the cathode filament forming die are connected through the press head guide rail column to form a guide mechanism;

[0010] The cathode filament forming mold and the cathode filament forming positioning groove are both provided with positioning grooves and limiting platforms, and the XY directions of the cathode filament forming mold are fixed by mutual cooperation and limiting;

[0011] The extrusion column is threadedly connected to the support frame to form a movable mechanism in the Z direction;

[0012] The support frame and the cathode filament forming mold are fixed by the fixing pin.

[0013] According to a preferred embodiment, the cathode filament forming mold, the cathode filament forming positioning groove and the cathode filament forming pressure head are made of molybdenum or tantalum, and the grain size of the molybdenum or tantalum is not greater than 90 μm.

[0014] According to a preferred embodiment, the angle between the two oblique sides of the cathode filament forming mold and the cathode filament forming press head is in the range of 40° to 45°.

[0015] According to a preferred embodiment, the bevel angle of the cathode filament forming positioning groove ranges from 20° to 22.5°, and the depth of the filament notch ranges from 1.5 mm to 2 mm.

[0016] According to a preferred embodiment, the bottom chamfer of the cathode filament forming mold is R0.3-R0.5.

[0017] According to a preferred embodiment, the bottom chamfer of the cathode filament forming press head is R0.2-R0.4.

[0018] According to a preferred embodiment, the roughness range of the cathode filament forming mold and the cathode filament forming press head is 0.4Ra to 0.8Ra.

[0019] According to another aspect of a preferred embodiment, the present application provides a method for forming a cathode filament of a space electron beam welding gun, the method comprising:

[0020] Step 1, obtaining a filament tungsten sheet and performing pre-processing on the filament tungsten sheet;

[0021] Step 2, the treated filament tungsten sheet is ultrasonically cleaned for 5 to 10 minutes using acetone as a medium, and then cleaned with deionized water for 2 to 4 times to ensure that the cleanliness reaches the level where there are no hard particles larger than 20 μm at the filter paper residue;

[0022] Step 3, installing the cleaned and dried filament tungsten sheet into the cathode filament forming positioning groove;

[0023] Step 4, pre-pressing the filament tungsten sheet;

[0024] Step 5, shaping and pressing the filament tungsten sheet;

[0025] Step 6, annealing the shaped filament tungsten sheet to relieve stress.

[0026] The technical solution provided by the embodiments of the present application may have the following beneficial effects:

[0027] In an embodiment of the present application, a cathode filament forming device for a space electron beam welding gun comprises: a pressure sensor, an extrusion column, a support frame, a pressure head guide column, a cathode filament forming pressure head, a cathode filament forming positioning groove, a cathode filament forming mold and a fixing pin, wherein: the extrusion column is connected to the pressure sensor to form a pressure sensing system; the extrusion column is fixedly connected to the cathode filament forming pressure head, and the cathode filament forming pressure head is pushed by the extrusion column to extrude the filament sheet; the cathode filament forming pressure head and the cathode filament forming mold are connected to form a guiding mechanism through the pressure head guide column; the cathode filament forming mold and the cathode filament forming positioning groove are both provided with positioning grooves and limit platforms, and the XY directions of the cathode filament forming mold are fixed by mutual cooperation and limitation; the extrusion column is threadedly connected to the support frame to form a movable mechanism in the Z direction; the support frame and the cathode filament forming mold are fixed by the fixing pin. The method for forming a cathode filament of a space electron beam welding gun comprises: step 1, obtaining a filament tungsten sheet and pre-processing the filament tungsten sheet; step 2, using acetone as a medium to ultrasonically clean the treated filament tungsten sheet for 5 minutes to 10 minutes, and washing it with deionized water for 2 to 4 times, to ensure that the cleanliness reaches the filter paper slag without hard particles larger than 20 μm; step 3, installing the cleaned and dried filament tungsten sheet into the cathode filament forming positioning groove; step 4, pre-pressing the filament tungsten sheet; step 5, shaping and pressing the filament tungsten sheet; and step 6, stress-relieving annealing the shaped filament tungsten sheet. The cathode filament forming device and method for a space electron beam welding gun described in the embodiment of the present application can simply and quickly meet the requirements of the cathode filament of a space electron beam welding gun, and can be promoted and applied to the field of electron beam processing in space stations; the device system is simple and the forming method process is convenient, and it can realize the simultaneous forming of multiple specifications of cathode filaments and batch forming of a single specification, forming a device with precisely controlled pressure, effectively meeting the needs of multifunctional applications of space electron beam welding guns; by preparing the cathode filament of a space electron beam welding gun through the present application, a finished product with good control design, high precision, small plastic deformation, and good comprehensive performance can be obtained, which is conducive to ensuring the quality of the beam spot.

[0028] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0030] Figure 1 It is a schematic diagram of the structural composition of a cathode filament forming device for a space electron beam welding gun provided in an embodiment of the present application;

[0031] Figure 2 It is a flow chart of a method for forming a cathode filament of a space electron beam welding gun provided in an embodiment of the present application.

[0032] Figure numerals: 1-pressure sensor; 2-extrusion column; 3-support frame; 4-pressure head guide column; 5-cathode filament forming pressure head; 6-cathode filament forming positioning groove; 7-cathode filament forming mold; 8-fixing pin. DETAILED DESCRIPTION

[0033] The following description and the drawings sufficiently illustrate specific embodiments of the invention to enable those skilled in the art to practice them.

[0034] It should be clear that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are only examples of systems and methods consistent with some aspects of the present invention as detailed in the attached claims.

[0036] In the description of the present invention, it should be understood that the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, in the description of the present invention, unless otherwise specified, "plurality" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the previously associated objects are in an "or" relationship.

[0037] The following will be combined with the attached Figure 1 -Attached Figure 2 , a cathode filament forming device and method for a space electron beam welding gun provided in an embodiment of the present application are introduced in detail.

[0038] The embodiment of the present application adopts pressure sensing extrusion forming and heat setting curing technology, which has the advantages of uniform plastic deformation of the filament, precise control and finalization of the key mechanical dimensions of the beam emission surface, and solidification and improvement of the stability of the filament structure, which matches the designed space electron beam welding gun device, improves the service life of the space electron beam welding gun, reduces the power requirements of the space electron beam welding power supply, and realizes the design requirements of miniaturization, lightness and high efficiency of the space electron beam device. In addition, the device can realize batch processing, while the stamping device used on the ground can only stamp one at a time, which has good prospects for automation and intelligent application; the filament formed by this technology is a special filament for the designed space electron beam welding device.

[0039] See also Figure 1 , which is a schematic diagram of the composition structure of a cathode filament forming device for a space electron beam welding gun according to an embodiment of the present application. Figure 1 As shown, a cathode filament forming device for a space electron beam welding gun described in an embodiment of the present application may include: a pressure sensor (1), an extrusion column (2), a support frame (3), a pressure head guide column (4), a cathode filament forming pressure head (5), a cathode filament forming positioning groove (6), a cathode filament forming mold (7) and a fixing pin (8), wherein:

[0040] The extrusion column (2) is connected to the pressure sensor (1) to form a pressure sensing system;

[0041] The extrusion column (2) is fixedly connected to the cathode filament forming press head (5), and the cathode filament forming press head (5) is pushed by the extrusion column (2) to extrude the filament sheet;

[0042] The cathode filament forming press head (5) and the cathode filament forming die (7) are connected via a press head guide rail column (4) to form a guide mechanism;

[0043] The cathode filament forming mold (7) and the cathode filament forming positioning groove (6) are both provided with positioning grooves and limiting platforms, and the XY directions of the cathode filament forming mold (7) are fixed by mutual limiting.

[0044] The extrusion column (2) and the support frame (3) are threadedly connected to form a movable mechanism in the Z direction;

[0045] The support frame (3) and the cathode filament forming mold (7) are fixed by means of a fixing pin (8).

[0046] Specifically, in the embodiment of the present application, the cathode filament forming mold (7), the cathode filament forming positioning groove (6) and the cathode filament forming pressure head (5) are made of molybdenum or tantalum, and the grain size of the molybdenum or tantalum is not greater than 90um; the extrusion column (2), the support frame (3), the pressure head guide column (4) and the fixing pin (8) are made of titanium alloy or stainless steel, and the stainless steel parts are subjected to vacuum degassing at 600°C to 650°C for 2 hours, and the titanium alloy parts are subjected to stress relief annealing at 620°C to 650°C for 1 hour to eliminate work hardening, reduce residual stress, enhance material plasticity, improve strength, and stabilize the material structure of the parts, thereby further ensuring the processing accuracy of the space electron beam cathode filament; the cathode filament forming mold (7) and the cathode filament forming positioning groove (6) are both provided with positioning grooves and limit tables, and the XY directions of the cathode filament forming mold (7) are fixed by mutual cooperation, and then the Z direction is limited by screws; in the embodiment of the present application, the support frame (3) and the cathode filament forming mold (7) can be fixed by four fixing The cathode filament forming mold (7) and the cathode filament forming pressure head (5) are fixed with a pin (8); the angle between the two oblique sides of the cathode filament forming mold (7) and the cathode filament forming pressure head (5) is controlled within the range of 40° to 45°; the oblique side angle of the cathode filament forming positioning groove (6) is controlled within the range of 20° to 22.5°; the depth of the filament notch is controlled within the range of 1.5 mm to 2 mm, the chamfer range of the bottom of the cathode filament forming mold (7) is R0.3 to R0.5, the chamfer range of the bottom of the cathode filament forming pressure head (5) is R0.2 to R0.4, and the roughness of the cathode filament forming mold (7) and the cathode filament forming pressure head (5) is controlled within the range of 0.4Ra to 0.8Ra; the accuracy of the pressure sensor (1) is controlled within the range of 0.001N·m to 0.005N·m. The pressure sensor (1) of the embodiment of the present application is a threaded force sensor, and the measurement of the pressure sensor (1) is achieved through torque; the cathode filament forming device for a space electron beam welding gun provided in the embodiment of the present application can simultaneously process cathode filaments of different specifications.

[0047] The present application embodiment provides a schematic flow chart of a method for forming a cathode filament of a space electron beam welding gun. Figure 2 As shown, the method of the embodiment of the present application may include the following steps:

[0048] Step 1, obtaining a filament tungsten sheet and pre-processing the filament tungsten sheet;

[0049] Step 2, the treated filament tungsten sheet is ultrasonically cleaned for 5 to 10 minutes using acetone as a medium, and then cleaned with deionized water for 2 to 4 times to ensure that the cleanliness reaches the level where there are no hard particles larger than 20 μm at the filter paper slag;

[0050] Step 3, installing the cleaned and dried filament tungsten sheet into the cathode filament forming positioning groove (6);

[0051] Step 4, pre-pressing the filament tungsten sheet;

[0052] Step 5, shaping and pressing the filament tungsten sheet;

[0053] Step 6, annealing the shaped filament tungsten sheet to relieve stress.

[0054] In the embodiment of the present application, the tungsten sheet for the filament is selected to have a tungsten content greater than 99.5%, a rhenium content in the range of 0.1% to 0.3%, a total potassium and nickel content of 0.1%, and a thickness of the tungsten sheet controlled within the range of 0.5 mm to 0.6 mm. In step 1, the tungsten sheet for the filament is pre-processed, including shearing the tungsten sheet into a tungsten sheet with a length of 26 mm and a width of 1 mm to 2 mm; the alloy elements rhenium, potassium, and nickel are elements that enhance the high-temperature toughness of the tungsten sheet; in step 4, when the tungsten sheet for the filament is pre-pressed, static The tightening torque should be controlled within the range of 20N·m to 25N·m, and the shaping time should be between 20min and 30min. In step 5, when the filament tungsten sheet is shaped and pressed, the static tightening torque should be controlled within the range of 38N·m to 41N·m, and the shaping time should be between 10min and 15min. In step 6, when the filament tungsten sheet is subjected to vacuum stress relief annealing after shaping, the temperature range should be controlled between 650℃ and 800℃, the stress relief time should be controlled between 1.5h and 2h, and the vacuum degree should be set to 2×10 -3 Pa, the cooling method is furnace cooling.

[0055] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0056] The above disclosure is only the preferred embodiment of the present application, which certainly cannot be used to limit the scope of rights of the present application. Therefore, equivalent changes made according to the claims of the present application are still within the scope covered by the present application.

Claims

1. A cathode filament forming device for a space electron beam welding gun, characterized in that: include: Pressure sensor, extrusion column, support frame, pressure head guide column, cathode filament forming pressure head, cathode filament forming positioning groove, cathode filament forming mold and fixing pin, wherein: The extrusion column is connected to the pressure sensor to form a pressure sensing system; The extrusion column is fixedly connected to the cathode filament forming press head, and the cathode filament forming press head is pushed by the extrusion column to extrude the filament sheet; The cathode filament forming press head and the cathode filament forming die are connected through the press head guide rail column to form a guide mechanism; The cathode filament forming mold and the cathode filament forming positioning groove are both provided with positioning grooves and limiting platforms, and the XY directions of the cathode filament forming mold are fixed by mutual cooperation and limiting; The extrusion column is threadedly connected to the support frame to form a movable mechanism in the Z direction; The support frame and the cathode filament forming mold are fixed by the fixing pin.

2. The cathode filament forming device for a space electron beam welding gun according to claim 1, characterized in that: The cathode filament forming mold, the cathode filament forming positioning groove and the cathode filament forming pressure head are made of molybdenum or tantalum, and the grain size of the molybdenum or tantalum is not greater than 90 μm.

3. The cathode filament forming device for a space electron beam welding gun according to claim 2, characterized in that: The angle between the two oblique sides of the cathode filament forming mold and the cathode filament forming pressure head is in the range of 40° to 45°.

4. The cathode filament forming device for a space electron beam welding gun according to claim 3, characterized in that: The cathode filament forming positioning groove has a bevel angle ranging from 20° to 22.5°, and a filament groove depth ranging from 1.5 mm to 2 mm.

5. The cathode filament forming device for a space electron beam welding gun according to claim 1, characterized in that: The bottom chamfer of the cathode filament forming mold is R0.3-R0.

5.

6. The cathode filament forming device for a space electron beam welding gun according to claim 5, characterized in that: The bottom chamfer of the cathode filament forming press head is R0.2-R0.

4.

7. The cathode filament forming device for a space electron beam welding gun according to claim 1, characterized in that: The roughness range of the cathode filament forming mold and the cathode filament forming press head is 0.4Ra to 0.8Ra.

8. A method for forming cathode filaments for space electron beam welding guns, characterized in that: The cathode filament forming device for a space electron beam welding gun according to claims 1 to 7 comprises: Step 1, obtaining a filament tungsten sheet and performing pre-processing on the filament tungsten sheet; Step 2, the treated filament tungsten sheet is ultrasonically cleaned for 5 to 10 minutes using acetone as a medium, and then cleaned with deionized water for 2 to 4 times to ensure that the cleanliness reaches the level where there are no hard particles larger than 20 μm at the filter paper residue; Step 3, installing the cleaned and dried filament tungsten sheet into the cathode filament forming positioning groove; Step 4, pre-pressing the filament tungsten sheet; Step 5, shaping and pressing the filament tungsten sheet; Step 6, annealing the shaped filament tungsten sheet to relieve stress.

9. The cathode filament forming method for a space electron beam welding gun according to claim 8, characterized in that: When the filament tungsten sheet is pre-pressed, the static tightening torque ranges from 20 N·m to 25 N·m, and the shaping time ranges from 20 min to 30 min.

10. The cathode filament forming device for a space electron beam welding gun according to claim 8, characterized in that: When the shaped filament tungsten sheet is subjected to vacuum stress relief annealing, the temperature range is 650° C. to 800° C., the stress relief time is 1.5 h to 2 h, and the cooling method is furnace cooling.

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