Curved surface microstructure laser-plasma combined machining device and method

Abstract

The invention discloses a curved surface microstructure laser-plasma combined machining device and method, and belongs to the technical field of non-traditional machining. The curved surface microstructure laser-plasma combined machining device comprises a plasma power supply, a gas supply system, a plasma generator, a nozzle assembly, a laser unit, a multi-axis moving unit, a vacuum clamp, a servo control system, a control panel and a machine tool body; and laser-plasma combined machining of the curved surface microstructure can be realized by combining linkage and interpolation movement of each shaft. Femtosecond laser is introduced into a plasma generation area, controllable output of a discharge plasma source is excited by the laser, micro plasma jet in a specific wavelength range is selected for micro-area localization machining, and the problem of machining defects caused by fluctuation and uneven distribution of jet particle energy in atmospheric plasma machining is solved. And meanwhile, laser is used for preheating in the machining area, energy needed by atom stripping of the to-be-machined material is reduced, the material atom stripping time is shortened, and the micro-plasma jet machining efficiency is greatly improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of special processing, and in particular, relates to a device and method for laser-plasma composite processing of curved surface microstructures. Background Art

[0002] The implosion process of inertial confinement fusion is to compress the outer shell of the target sphere toward the center of the target sphere through a strong radiation field, so that the fuel in the shell is continuously condensed and heated until the ignition conditions are met. Due to the inherent defects on the target surface, the outer shell is compressed asymmetric, which will cause the implosion to first appear at the weak part of the target surface during the propagation of internal energy to the outside, forcing the target shell to rupture or the fuel shell surface to produce Rayleigh-Taylor (RT) instability, which leads to a significant decrease in the implosion performance or even failure. The roughness and defects of the target surface have a great influence on the RT instability. Therefore, it is urgent to prepare a modulated micro-nanostructure target with controllable size, introduce a sinusoidal modulation pattern on the target surface to simulate the inhomogeneity of the target pellet surface, and obtain information on the growth of RT instability by measuring the nonlinear growth of the spatiotemporal distribution of the target density disturbance during the laser ablation of the target, which is of great significance to improving the reliability of the implosion. At present, there is still a lack of effective processing methods to solve the problem of brittle fracture of the target sphere, which is very easy to occur when processing micro-nano structures on the surface of the target sphere made of low-rigidity HDC materials. It is urgent to study new methods for high-precision manufacturing of micro-nano structures on the surface of the target sphere.

[0003] Atmospheric pressure plasma jet is a new type of plasma jet technology that has gradually emerged in recent years. It is one of the research hotspots in the field of plasma science and engineering at home and abroad. It uses the effect of airflow and electric field to make the plasma generated in the discharge area ejected from the nozzle or orifice, and flow in a directional manner in an unconstrained external environment, so as to transport active particles and high-energy particles to the surface of the material to be processed in the downstream working area through the jet to achieve the purpose of removing materials. Its advantages are simple structure, convenient operation, high safety and good practicality. Especially for experimental materials with unique shapes and temperature sensitivity, it highlights its advantages over previous methods such as laser and ion beam processing, and is a potential means for high-precision manufacturing of micro-nano structures on the surface of HDC target balls. Traditionally, parallel plate capacitive coupling discharge devices are mostly used in plasma discharge systems. The limitation of the frequency of the plasma excitation source greatly reduces the processing efficiency of the plasma jet, and the uncontrollability of the plasma cloud distribution affects the forming accuracy of the micro-nano structure. At the same time, the complex shape of the processed sample will also affect the discharge mode and stability. In order to improve the working efficiency and stable controllability of plasma jets, people have been committed to the development of large-area stable plasma jets. However, the research and development of efficient, large-area, and stable plasma jets has been a challenging problem facing people for decades. Summary of the invention

[0004] In view of the problems existing in the prior art, in order to solve the difficulty of high-precision and high-quality processing of curved surface micro-nano structures of low-rigidity temperature-sensitive materials, the purpose of the present invention is to propose a curved surface microstructure laser-plasma composite processing device and method.

[0005] The technical solution adopted by the present invention to achieve the above-mentioned purpose is:

[0006] According to the first aspect of the present invention, there is provided a curved microstructure laser-plasma composite processing device, comprising: a plasma power supply, a gas supply system, a plasma generator, a nozzle assembly, a laser unit, a multi-axis moving unit, a vacuum fixture, a servo control system, a control panel, and a machine tool bed. The plasma power supply is used to provide stable electric energy to the plasma generator connected thereto; the gas supply system is used to provide working gas for the plasma generator, including a gas cylinder cabinet, a gas cylinder, a barometer, a gas valve, and a gas pipe. The working gas stored in the gas cylinder is transported to the working area of ​​the plasma generator through the gas pipe by opening the gas valve, and the barometer can adjust the gas supply pressure; the plasma generator is used to generate plasma, including a power line, a high-voltage electrode, a cavity (ground electrode), and an adapter plate. The power line transmits the high-voltage electricity generated by the plasma power supply to the high-voltage electrode, and forms an extremely high electric field with the cavity (ground electrode), resulting in tip discharge, ionizing the working gas provided by the gas supply system to generate plasma, and the adapter plate is used for the installation of the plasma generator and the Z-axis translation table; the nozzle assembly is used to form a beam of plasma generated by the plasma generator, and transport it to the processing area by ejecting the working gas, including a nozzle and a nozzle; the laser The unit is used to apply femtosecond laser to the plasma generation and plasma processing area, including an optical path module, an optical fiber, and a focusing system. The femtosecond laser of the optical path module generates femtosecond laser, which is expanded and collimated by a beam expander and collimator, split by a beam splitter, and then transmitted to the frequency doubling crystal 1 and the frequency doubling crystal 2 of the focusing module 1 and the focusing module 2 to adjust the wavelength. Finally, after passing through the focusing mirror 1 and the focusing mirror 2, it acts on the plasma generation and plasma processing area; the multi-axis moving unit is used for the multi-axis movement of the focusing module, the plasma generator and the workpiece to be processed of the laser unit, including a Z-axis translation table, an X-axis translation table, a Y-axis translation table, an A-axis turntable, and a B-axis swing table; the vacuum fixture is installed on the A-axis turntable, used for clamping the curved surface workpiece to be processed, including a suction cup, a suction pipe, a bracket, and a vacuum pump; the servo control system is used to control the interpolation movement of the multi-axis moving table; the control panel is used for the integrated control of the plasma power supply, the laser unit, and the multi-axis moving unit.

[0007] Furthermore, the plasma power supply utilizes a variable frequency power supply for excitation, a digital control mode, and has high output accuracy. It adopts a phase-shifted full-bridge soft switching circuit to reduce the impact of fluctuations in gas pressure and city grid voltage, and ensure that the output voltage and current are stable and reliable.

[0008] Furthermore, the gas supply system can provide different types of gases according to the differences in material properties of the workpiece to be processed, including helium, nitrogen, argon, etc., which is suitable for processing different materials, and controls the shape of the plasma beam by controlling the pressure of the working gas.

[0009] Furthermore, the plasma generator transmits the high voltage electricity generated by the plasma power supply to the high voltage electrode, forming an extremely high electric field with the cavity (ground electrode), causing tip discharge, ionizing the working gas provided by the gas supply system, and generating plasma.

[0010] Furthermore, the nozzle assembly includes a nozzle and a nozzle, wherein the nozzle is made of a glass tube. The nozzle of the required diameter is drawn by a needle drawing instrument, and then the nozzle outlet is trimmed by a needle grinding instrument. The nozzle outlet diameter is between 3μm-100μm, and nozzles of different specifications can be selected according to process requirements.

[0011] Furthermore, the laser unit adopts a red light femtosecond laser with a wavelength of 650nm. The femtosecond laser generated by the optical path module can be divided into two beams of light by a spectroscope. The energy ratio is adjusted by frequency doubling crystals 1 and 2 of focusing module 1 and focusing module 2 to achieve conversion of lasers of different wavelengths. One laser acts on the plasma generation area, and the other laser acts on the plasma processing area.

[0012] Furthermore, the stroke of the Z-axis translation table in the multi-axis mobile unit is 100mm, the positioning accuracy is ±1um, and the resolution is 0.03um; the stroke of the X-axis translation table and the Y-axis translation table is 200mm, the positioning accuracy is ±1um, and the resolution is 0.05um; the translation table guide rail adopts a hydrostatic guide rail and a hydrostatic drive mode; the positioning accuracy of the A-axis turntable and the B-axis swing table is better than 1arcsec.

[0013] Furthermore, the vacuum clamp can automatically and continuously complete program-controlled processing under one clamping condition by executing a pre-input program, and has high efficiency, high precision and high reliability.

[0014] Furthermore, the servo control system controls the linkage and differential compensation motion of the multi-axis mobile unit through a control panel, and the interpolation methods include spline interpolation, linear interpolation, circular arc interpolation, and spiral interpolation to achieve high-precision processing of curved surface microstructures.

[0015] Furthermore, the machine tool bed is made of artificial marble, which has high rigidity, good vibration absorption and precision stability.

[0016] According to a second aspect of the present invention, a method for laser-plasma composite processing of curved surface microstructures is provided. The method adopts the above-mentioned laser-plasma composite processing device for curved surface microstructures for processing, and specifically comprises the following steps, and the following steps are performed in sequence:

[0017] Step 1: According to the processing requirements, select a nozzle with a corresponding outlet diameter and install it on the nozzle, select a suitable working gas, select a suitable laser wavelength and adjust the wavelength through a frequency doubling crystal;

[0018] Step 2: Use a vacuum fixture to clamp the workpiece to be processed, turn on the vacuum pump, and fix the workpiece to be processed by the suction cup;

[0019] Step 3: According to the surface microstructure processing requirements of the workpiece to be processed, the pre-programmed processing program is input into the servo control system and controlled through the control panel. The displacement and rotation parameters of each axis in the multi-axis mobile unit include the moving speed and length of the Z-axis translation table, the X-axis translation table, and the Y-axis translation table, and the rotation and swing speed and angle of the A-axis turntable and the B-axis swing table;

[0020] Step 4: Open the gas valves of the plasma power supply and the gas supply system, and control the shape of the plasma beam by controlling the pressure of the working gas.

[0021] Step 5: Turn on the focusing beam of the femtosecond laser, set the workpiece coordinate system through the control panel, and manually control the multi-axis moving unit to move, so that the laser and plasma jet processing beam spot is accurately positioned to the processing position of the workpiece to be processed, adjust the working distance of the laser and plasma jet, and turn off the focusing beam of the femtosecond laser.

[0022] Step 6: Turn on the processing beam of the femtosecond laser, start the processing program through the control panel, and perform surface microstructure laser-plasma composite processing.

[0023] Step 7: Stop the processing program, turn off the power of the femtosecond laser and plasma, close the gas valve of the gas supply system, turn off the power of the vacuum pump, and remove the workpiece.

[0024] Through the above design scheme, the present invention can bring the following beneficial effects:

[0025] First, by introducing femtosecond lasers in the plasma generation area, using the controllable output of the laser-excited discharge plasma source, realizing multi-beam source plasma jet shaping through lasers, and selecting microplasma jets in a specific wavelength range for micro-area localized processing, the processing defects caused by the fluctuation and uneven distribution of jet particle energy in atmospheric plasma processing can be solved.

[0026] Second, by introducing a femtosecond laser into the plasma processing area and using the laser to preheat the processing area, the energy required for atomic stripping of the material to be processed is reduced, thereby shortening the time it takes for the microplasma jet to strip atoms from the material in the processing area, greatly improving the microplasma jet processing efficiency.

[0027] Third, by determining the coordinate relationship between the laser spot and the plasma beam spot, utilizing the linkage of each axis of the multi-axis moving unit and combining the interpolation motion of each axis, laser-plasma composite processing of curved surface microstructures can be achieved.

[0028] Fourth, the nozzle is made of glass tube. The nozzle of required diameter is drawn by a needle puller, and the nozzle outlet is trimmed by a needle grinder. Nozzles with different nozzle diameters can be made according to process requirements. By replacing the nozzle, the system can process a wider range of microstructure scales and has stronger applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present application. The exemplary embodiments of the present invention and their descriptions are used to understand the present invention and do not constitute improper limitations of the present invention. In the drawings:

[0030] Figure 1 Schematic diagram of the structure of the curved surface microstructure laser-plasma composite processing device in an embodiment of the present invention;

[0031] Figure 2 Schematic diagram of a plasma generator in an embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram of the structure of the optical path module of the laser unit in an embodiment of the present invention;

[0033] Figure 4 Schematic diagram of the structure of the focusing module 1 of the laser unit in an embodiment of the present invention;

[0034] Figure 5 Schematic diagram of the structure of the focusing module 2 of the laser unit in an embodiment of the present invention;

[0035] Figure 6 This is a schematic diagram of the structure of a vacuum clamp in an embodiment of the present invention;

[0036] Figure 7 It is a partial enlarged view of the processing area of ​​the curved surface microstructure laser-plasma composite processing device in an embodiment of the present invention;

[0037] In the figure: 1-plasma power supply; 2-gas supply system; 201-gas cylinder cabinet; 202-gas cylinder; 203-barometer; 204-gas valve; 205-gas pipe; 3-plasma generator; 301-power line; 302-high voltage electrode; 303-cavity (ground electrode); 304-adapter plate; 4-nozzle assembly; 401-nozzle; 402-nozzle; 5-laser unit; 501-optical path module; 502-optical fiber; 503-focusing module 1; 504-focusing module Block 2; 6-multi-axis moving unit; 601-Z-axis translation table; 602-X-axis translation table; 603-Y-axis translation table; 604-A-axis turntable; 605-B-axis swing table; 7-vacuum fixture; 8-servo control system; 9-control panel; 10-machine tool bed, 5011-femtosecond laser; 5012-beam expansion collimator; 5013-beam splitter, 5031-frequency doubling crystal one; 5032-focusing mirror one, 5041-frequency doubling crystal two; 5042-focusing mirror two. DETAILED DESCRIPTION

[0038] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical scheme in the present invention is clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the present invention is not limited by the following embodiments, and the specific implementation method can be determined according to the technical scheme of the present invention and the actual situation. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meanings understood by people with general skills in the field to which the present invention belongs. In order to avoid confusing the essence of the present invention, the known methods, processes, processes and components are not described in detail. In the present invention, unless there are other clear provisions and limited components, the components are all general standard parts or components known to those skilled in the art, and their structures and principles are known to those skilled in the art through technical manuals or through conventional experimental methods. The terms "set", "install", "connect", "connect" and the like should be understood in a broad sense. For example, "fixed" can be a fixed connection, a detachable connection, or an integral connection; the connection can be a mechanical connection or an electrical connection; the connection can be a direct connection, or it can be indirectly connected through an intermediate medium, and it can be the internal connection of two components or the interaction relationship between two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0039] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, Figure 1The structure of a curved surface microstructure laser-plasma composite processing device is shown, including: 1-plasma power supply; 2-gas supply system; 201-gas cylinder cabinet; 202-gas cylinder; 203-barometer; 204-gas valve; 205-gas pipe; 3-plasma generator; 301-power line; 4-nozzle assembly; 5-laser unit; 501-optical path module; 502-optical fiber; 503-focusing module one; 504-focusing module two; 6-multi-axis moving unit; 601-Z-axis translation table; 602-X-axis translation table; 603-Y-axis translation table; 604-A-axis turntable; 605-B-axis swing table; 7-vacuum fixture; 702-suction tube; 704-vacuum pump; 8-servo control system; 9-control panel; 10-machine bed. Figure 2 The structure of 3-plasma generator is shown, including: 301-power line; 302-high voltage electrode; 303-cavity (ground electrode); 304-adapter plate. Figure 3 The optical path module structure 501 is shown, including: 5011 - femtosecond laser; 5012 - beam expander collimator; 5013 - beam splitter. Figure 4 The structure of 503-focusing module 1 is shown, including: 5031-frequency doubling crystal 1; 5032-focusing mirror 1. Figure 5 The structure of 504-focusing module 2 is shown, including: 5041-frequency doubling crystal 2; 5042-focusing mirror 2. Figure 6 The structure of the 7-vacuum clamp is shown, including: 701-suction cup; 702-suction tube; 703-bracket; 704-vacuum pump. Figure 7 A partial enlarged view of the processing area of ​​the curved microstructure laser-plasma composite processing device is shown, including: 303-cavity (ground electrode) in the processing area; 401-nozzle; 402-nozzle; 503-focusing module one; 504-focusing module two; 605-B-axis swing table; 7-vacuum clamp.

[0040] The plasma power supply 1 is connected to the plasma generator 3 through a power line 301 to provide stable electric energy for the plasma generator 3; a variable frequency power supply is used for excitation, a digital control method is used, and the output precision is high. A phase-shifted full-bridge soft switching circuit is used to reduce the influence of fluctuations in air pressure and mains voltage, and ensure that the output voltage and current are stable and reliable.

[0041] The gas supply system 2 is used to provide working gas for the plasma generator 3, and includes a gas cylinder cabinet 201, a gas cylinder 202, a barometer 203, a gas valve 204, and a gas pipe 205. By opening the gas valve 204, the working gas stored in the gas cylinder 202 is transported to the working area of ​​the plasma generator 3 through the gas pipe 205.

[0042] The plasma generator 3 is used to generate plasma, and includes a power line 301, a high-voltage electrode 302, a cavity (ground electrode) 303, and an adapter plate 304. The power line 301 transmits the high-voltage electricity generated by the plasma power supply 1 to the high-voltage electrode 302, and forms an extremely high electric field with the cavity (ground electrode) 303, resulting in tip discharge, ionizing the working gas provided by the gas supply system 2 to generate plasma. The adapter plate 304 is used to install the plasma generator 3 on the Z-axis translation table 601.

[0043] The nozzle assembly 4 is used to form a beam of plasma generated by the plasma generator 3 and transport it to the processing area through the injection of working gas, and includes a nozzle 401 and a nozzle 402. The nozzle 401 is installed on the cavity (ground electrode) 403 in a threaded connection form, and the nozzle 402 is fixed at the outlet of the nozzle 401 in an interference fit manner.

[0044] The laser unit 5 is used to apply femtosecond laser to the plasma generation and plasma processing areas, and includes an optical path module 501, an optical fiber 502, a focusing module 1 503, and a focusing module 2 504; wherein the optical path module 501 includes a femtosecond laser 5011, a beam expander collimator 5012, and a spectrometer 5013, and the focusing module 1 503 includes a frequency doubling crystal 1 5031 and a focusing mirror 1 5032. Figure 5 The structure of the focusing module 2 504 is shown, including the frequency doubling crystal 2 5041 and the focusing mirror 2 5042. The femtosecond laser 5011 generates a femtosecond laser, which is expanded and collimated by the beam expander collimator 5012, and then split into two laser beams by the beam splitter 5013. The two laser beams enter the focusing module 1 503 and the focusing module 2 504 through the optical fiber 502, and then adjust the wavelength by the frequency doubling crystal 1 5031 and the frequency doubling crystal 2 5041, and finally focus by the focusing mirror 1 5032 and the focusing mirror 2 5042, and act on the plasma generation and plasma processing areas respectively.

[0045] The multi-axis moving unit 6 is used for multi-axis movement of the workpiece to be processed, the Z-axis translation table 601 can realize movement along the Z-axis direction, the X-axis translation table 602 can realize movement along the X-axis direction, the Y-axis translation table 603 can realize movement along the Y-axis direction, and the X-axis translation table 602 is installed on the Y-axis translation table 603. The A-axis turntable 604 is installed on the B-axis swing table 605, and the B-axis swing table 605 is installed on the X-axis moving table 602, so that the A-axis turntable 604 and the B-axis swing table 605 can realize movement along the X-axis and Y-axis directions while rotating and swinging. The stroke of the Z-axis translation table 601 is 100mm, the positioning accuracy is ±1um, and the resolution is 0.03um; the stroke of the X-axis translation table 602 and the Y-axis translation table 603 is 200mm, the positioning accuracy is ±1um, and the resolution is 0.05um; the translation table guide rails adopt hydrostatic guide rails and hydrostatic drive mode; the positioning accuracy of the A-axis turntable 604 and the B-axis swing table 605 is better than 1arcsec.

[0046] The vacuum fixture 7 is mounted on the A-axis turntable 604 and is used to clamp the workpiece to be processed. It includes a suction cup 701, a suction pipe 702, a bracket 703, and a vacuum pump 704. The suction cup 701 is connected to the vacuum pump 704 through the suction pipe 702, and a vacuum is generated by turning on the vacuum pump 704 to fix the workpiece to be processed. The vacuum fixture 7 can automatically and continuously complete program-controlled processing under one-time clamping conditions by executing a pre-input program, and has high efficiency, high precision, and high reliability.

[0047] The servo control system 8 is connected to the Z-axis translation table 601, the X-axis translation table 602, the Y-axis translation table 603, the A-axis rotary table 604, and the B-axis swing table 605 to achieve precise displacement control of the Z-axis translation table 601, the X-axis translation table 602, and the Y-axis translation table 603, and precise rotation angle control of the A-axis rotary table 604 and the B-axis swing table 605. The servo control system 8 controls the linkage and differential compensation motion of the multi-axis mobile unit 6 through the control panel 9, and the interpolation methods include spline interpolation, linear interpolation, circular interpolation, and spiral interpolation to achieve high-precision processing of curved surface microstructures.

[0048] The control panel 9 is connected to the plasma power supply 1, the laser unit 5, and the servo control system 8, and is used to control the switch of the plasma power supply 1 and the adjustment of parameters such as voltage, power, and air pressure, as well as control the femtosecond laser switch and power of the laser unit 5, and further control the linkage and differential compensation movement of the multi-axis mobile unit 6 through the servo control system 8.

[0049] The machine tool bed 10 is made of artificial marble, has high rigidity, good vibration absorption and precision stability, and is used to support the plasma power supply 1, the plasma generator 3, the laser unit 5, the multi-axis moving unit 6, the servo control system 8 and the control panel 9.

[0050] A curved surface microstructure laser-plasma composite processing method, which uses the curved surface microstructure laser-plasma composite processing device for processing, specifically includes the following steps, and the following steps are performed in sequence:

[0051] Step 1: According to the processing requirements, select a nozzle 402 with a corresponding outlet diameter and install it on the nozzle 401, select a suitable working gas, select a suitable laser wavelength and adjust the wavelength through the frequency doubling crystal 1 5031 and the frequency doubling crystal 2 5041;

[0052] Step 2: Use the vacuum fixture 7 to clamp the workpiece to be processed, turn on the vacuum pump 704, and fix the workpiece to be processed through the suction cup 701;

[0053] Step 3: According to the processing requirements of the surface microstructure of the workpiece to be processed, the pre-programmed processing program is input into the servo control system 8 and controlled through the control panel 9. The displacement and rotation parameters of each axis in the multi-axis mobile unit 6 include the moving speed and length of the Z-axis translation table 601, the X-axis translation table 602, and the Y-axis translation table 603, and the rotation and swing speed and angle of the A-axis turntable 604 and the B-axis swing table 605;

[0054] Step 4: Open the gas valve 204 of the plasma power supply 1 and the gas supply system 2, and control the shape of the plasma beam by controlling the gas pressure of the working gas. In order to prevent arc discharge, the gas pressure is generally controlled at more than 0.1 MPa, so that the plasma is blown out quickly without forming an arc. At the same time, the gas pressure cannot be too high, otherwise the plasma jet cannot be formed.

[0055] Step 5: Turn on the focusing beam of the femtosecond laser 5011, set the workpiece coordinate system through the control panel 9, and manually control the multi-axis moving unit 5 to move, so that the laser and plasma jet processing beam spot is accurately positioned to the processing position of the workpiece to be processed, adjust the working distance of the laser and plasma jet, and turn off the focusing beam of the femtosecond laser 5011.

[0056] Step 6: Turn on the processing beam of the femtosecond laser 5011, start the processing program through the control panel 9, and perform the surface microstructure laser-plasma composite processing.

[0057] Step 7: The processing program stops, the power supply of the femtosecond laser 5011 and the plasma power supply 1 are turned off, the gas valve 204 of the gas supply system 2 is closed, the vacuum pump 704 is turned off, and the workpiece is removed.

[0058] The present invention introduces a femtosecond laser into the plasma generation area, utilizes the controllable output of the laser-excited discharge plasma source, realizes multi-beam source plasma jet shaping through laser, selects micro plasma jets in a specific wavelength range for micro-region localized processing, and solves the processing defect problem caused by the fluctuation and uneven distribution of jet particle energy in atmospheric plasma processing. At the same time, the laser is used to preheat the processing area to reduce the energy required for atomic stripping of the material to be processed, thereby shortening the atomic stripping time of the micro plasma jet on the material in the processing area, greatly improving the processing efficiency of the micro plasma jet. By determining the coordinate relationship between the laser spot and the plasma beam spot, combined with the linkage and interpolation motion of each axis, laser-plasma composite processing of curved microstructures can be achieved.

Claims

1. A curved surface microstructure laser-plasma composite processing device, characterized in that: include: A plasma power supply (1), a gas supply system (2), a plasma generator (3), a nozzle assembly (4), a laser unit (5), a multi-axis moving unit (6), a vacuum fixture (7), a servo control system (8), a control panel (9), and a machine tool bed (10). The plasma power supply (1) is used to provide stable electric energy to the plasma generator (3) connected thereto; the gas supply system (2) is used to provide working gas to the plasma generator (3), and comprises a gas cylinder cabinet (201), a gas cylinder (202), a barometer (203), a gas valve (204), and a gas pipe (205). The working gas stored in the gas cylinder (202) is transported to the plasma generator through the gas pipe (205) by opening the gas valve (204). The plasma generator (3) is provided with a working area, wherein the barometer (203) is capable of adjusting the gas supply pressure; the plasma generator (3) is used to generate plasma, and comprises a power line (301), a high-voltage electrode (302), a cavity (303), and an adapter plate (304); the power line (301) transmits the high-voltage electricity generated by the plasma power source (1) to the high-voltage electrode (302), and forms an electric field with the cavity (303), resulting in tip discharge, ionizing the working gas provided by the gas supply system (2), and generating plasma; the adapter plate (304) is used to install the plasma generator (3) and the Z-axis translation table (601); the nozzle assembly (4) is used to form a beam of plasma generated by the plasma generator (3), and pass the plasma into the plasma generator (3) through the nozzle assembly (4). The plasma is transported to the processing area by the injection of working gas, and includes a nozzle (401) and a nozzle (402); the laser unit (5) is used to apply femtosecond laser to the plasma generation and plasma processing area, and includes an optical path module (501), an optical fiber (502), and a focusing module (503); the femtosecond laser (5011) of the optical path module (501) generates femtosecond laser, which is expanded and collimated by a beam expander and collimator (5012), split by a beam splitter (5013), and then transmitted through the optical fiber (502) to the frequency doubling crystals 1 (5031) and 2 (5041) of the focusing module 1 (503) and the focusing module 2 (504) to adjust the wavelength, and finally passes through the focusing mirrors 1 (5032) and 2 (5042) ) and then acts on the plasma generation and plasma processing area; the multi-axis moving unit (6) is used for the multi-axis movement of the workpiece to be processed, including a Z-axis translation table (601), an X-axis translation table (602), a Y-axis translation table (603), an A-axis turntable (604), and a B-axis swing table (605); the vacuum fixture (7) is installed on the A-axis turntable (604) and is used to clamp the curved surface workpiece to be processed, including a suction cup (701), a suction pipe (702), a bracket (703), and a vacuum pump (704); the servo control system (8) is used to control the interpolation movement of the multi-axis moving table (6); and the control panel (9) is used for the integrated control of the plasma power supply (1), the laser unit (5), and the multi-axis moving unit (6).

2. The curved surface microstructure laser-plasma composite processing device according to claim 1, characterized in that: The plasma power supply (1) is a variable frequency power supply excitation mode, a digital control mode, and adopts a phase-shifted full-bridge soft switching circuit.

3. The curved surface microstructure laser-plasma composite processing device according to claim 1, characterized in that: The gas supply system (2) can provide different types of gases according to the material properties of the workpiece to be processed, including helium, nitrogen, argon, etc., suitable for processing different materials, and controls the shape of the plasma beam by controlling the pressure of the working gas.

4. The curved surface microstructure laser-plasma composite processing device according to claim 1, characterized in that: The plasma generator (3) transmits the high voltage electricity generated by the plasma power supply (1) to the high voltage electrode (302), forms an 8KV electric field with the cavity (303), causes tip discharge, ionizes the working gas provided by the gas supply system (2), and generates plasma.

5. The curved surface microstructure laser-plasma composite processing device according to claim 1, characterized in that: The nozzle assembly (4) comprises a nozzle (401) and a nozzle (402), wherein the nozzle (401) is made of a glass tube, a nozzle of a required diameter is drawn by a needle drawing instrument, and then the nozzle outlet is trimmed by a needle grinding instrument, the nozzle (402) outlet diameter is between 3 μm and 100 μm, and nozzles (402) of different specifications are selected according to process requirements.

6. The curved surface microstructure laser-plasma composite processing device according to claim 1, characterized in that: The laser unit (5) uses a red light femtosecond laser with a wavelength of 650nm. The femtosecond laser generated by the optical path module (501) can be split into two beams of light by a beam splitter (5013). The energy ratio is adjusted by frequency doubling crystal 1 (5031) and frequency doubling crystal 2 (5041) of focusing module 1 (503) and focusing module 2 (504) to achieve conversion of lasers of different wavelengths. One beam of laser acts on a plasma generation area, and the other beam of laser acts on a plasma processing area.

7. The curved surface microstructure laser-plasma composite processing device according to claim 1, characterized in that: The stroke of the Z-axis translation table (601) in the multi-axis mobile unit (6) is 100 mm, the positioning accuracy is ±1 um, and the resolution is 0.03 um; the stroke of the X-axis translation table (602) and the Y-axis translation table (603) is 200 mm, the positioning accuracy is ±1 um, and the resolution is 0.05 um; the translation table guide rails adopt hydrostatic guide rails and hydrostatic drive mode; the positioning accuracy of the A-axis turntable (604) and the B-axis swing table (605) is better than 1 arc second.

8. The curved surface microstructure laser-plasma composite processing device according to claim 1, characterized in that: The vacuum clamp (7) can automatically and continuously complete program-controlled processing by executing a pre-input program under a one-time clamping condition.

9. The curved surface microstructure laser-plasma composite processing device according to claim 1, characterized in that: The servo control system (8) controls the linkage and differential compensation motion of the multi-axis mobile unit (6) through a control panel (9), and the interpolation methods include spline interpolation, linear interpolation, circular arc interpolation, and spiral interpolation.

10. A method for laser-plasma composite processing of curved surface microstructures, characterized in that: The method adopts a curved surface microstructure laser-plasma composite processing device as described in claims 1-9 for processing, and specifically comprises the following steps, and the following steps are performed in sequence: Step 1: According to the processing requirements, a nozzle (402) with a corresponding outlet diameter is selected and installed on the nozzle (401), a suitable working gas is selected, a suitable laser wavelength is selected and the wavelength is adjusted through a frequency doubling crystal 1 (5031) and a frequency doubling crystal 2 (5041); Step 2: Clamp the workpiece to be processed using a vacuum fixture (7), turn on the vacuum pump (704), and fix the workpiece to be processed using the suction cup (701); Step 3: According to the processing requirements of the surface microstructure of the workpiece to be processed, the pre-compiled processing program is input into the servo control system (8), and the displacement and rotation parameters of each axis in the multi-axis mobile unit (6) are controlled through the control panel (9), including the moving speed and length of the Z-axis translation table (601), the X-axis translation table (602), and the Y-axis translation table (603), and the rotation, swing speed and angle of the A-axis turntable (604) and the B-axis swing table (605); Step 4: Open the gas valve (204) of the plasma power supply (1) and the gas supply system (2), and control the shape of the plasma beam by controlling the gas pressure of the working gas, and the gas pressure is above 0.1 MPa; Step 5: Turn on the focusing beam of the femtosecond laser (5011), set the workpiece coordinate system through the control panel (9), and control the multi-axis moving unit (6) to move, so that the laser and plasma jet processing beam spot is accurately positioned to the processing position of the workpiece to be processed, adjust the working distance of the laser and plasma jet, and turn off the focusing beam of the femtosecond laser (5011); Step 6: Turn on the processing beam of the femtosecond laser (5011), start the processing program through the control panel (9), and perform laser-plasma composite processing of the curved surface microstructure; Step 7: The processing program stops, the power of the femtosecond laser (5011) and the plasma power (1) are turned off, the gas valve (204) of the gas supply system (2) is closed, the power of the vacuum pump (704) is turned off, and the workpiece is removed.

Images