Electrochemical discharge-laser-dynamic wet etching processing system, method and applications

Abstract

The application discloses an electrochemical discharge-laser-dynamic wet etching processing system, method and application, and belongs to the field of special processing. The electrochemical discharge-laser-dynamic wet etching composite processing system comprises an electrochemical discharge processing module, a laser processing module and a jet module. The electrochemical discharge processing module is used for performing electrochemical discharge processing on a first region of a workpiece; the laser processing module is used for performing laser ablation processing on a second region of the workpiece, and the first region is distributed around the second region; and the jet module is used for performing jet flushing on a processing region of the workpiece, and the processing region comprises the second region and the first region. The application combines the high-precision advantage of electrochemical discharge processing, utilizes laser processing to improve processing efficiency, adopts dynamic chemical solution to selectively etch the oxide layer generated in the processing process of the workpiece material, and timely updates the solution state, so that a processing scheme with high efficiency, high precision and high surface quality is formed.

Description

TECHNICAL FIELD

[0001] The present application relates to an electrochemical discharge-laser-dynamic wet etching processing system, method and application, and belongs to the technical field of special processing. BACKGROUND

[0002] Hard and brittle materials are difficult to machine due to their high hardness and brittleness and anisotropy. Traditional mechanical machining is prone to cause serious tool wear and defects such as fiber breakage, porosity, interface separation and cracks. Special processing techniques have been used to try to machine hard and brittle materials, such as water jet machining, laser machining and electrochemical discharge machining. As non-contact processing, they can effectively overcome the limitations of mechanical machining. Water jet machining relies on jet impact to cause material fatigue fracture to remove material, and there is no thermal stress and thermal deformation during processing. However, when dealing with hard and brittle materials, uneven load distribution caused by hydraulic impact can cause obvious delamination. Laser machining can achieve precise material removal by focusing the beam on the material surface, and it performs outstandingly in micro-machining. However, it has obvious taper when machining deep and small holes, and the machining precision needs to be improved. Electrical discharge machining can copy complex electrode shapes to the workpiece to form high-precision profiles, but some hard and brittle materials have poor machinability due to their poor electrical conductivity.

[0003] In order to solve the problem of precision machining of non-conductive materials, electrochemical discharge machining is applied. However, when machining deep and small holes, short circuit caused by poor chip removal can easily occur, resulting in low machining efficiency. CN104942388A discloses a device and method for electrochemical discharge and laser combined machining of materials. In the immersion solution, laser energy and discharge energy act on the upper surface and lower surface of the workpiece respectively, thereby improving the etching speed of the workpiece material. For the hole making process of hard and brittle materials, on the one hand, the immersion solution still has the problem of poor chip removal, and on the other hand, the machining precision of laser and electrochemical discharge machining cannot be consistent, resulting in distortion of the hole type at the junction of the two energy fields. In addition, hard and brittle materials such as SiC / SiC composite materials are prone to oxidation under high temperature conditions, which reduces the surface quality of the hole wall, which limits the laser machining and electrochemical discharge machining that removes material by thermal effect.

[0004] Chemical etching process can be used as a surface finishing process to improve the laser-electrochemical discharge combined machining of hard and brittle materials, and the introduction of jet flow is also beneficial to improve the chip removal capacity during processing. How to effectively combine the comprehensive effects of laser machining, electrochemical discharge machining, chemical etching and jet flow to realize high-efficiency, high-precision and high-surface-quality hole making process of hard and brittle materials has very important engineering application value for the application and development of aviation manufacturing technology. SUMMARY

[0005] The main purpose of the present application is to provide an electrochemical discharge-laser-dynamic wet etching processing system, method and application, so as to overcome the deficiencies in the prior art.

[0006] In order to achieve the above-mentioned purposes, the technical scheme adopted by the present application comprises:

[0007] The first aspect of the embodiment of the present application provides an electrochemical discharge-laser-dynamic wet etching composite processing system, which comprises:

[0008] An electrochemical discharge processing module, which is used at least for electrochemical discharge processing of a first region of a workpiece to remove the material of the first region of the workpiece;

[0009] A laser processing module, which is used at least for laser ablation processing of a second region of the workpiece to remove the material of the second region of the workpiece, the first region being distributed around the second region, and the first region and the second region being adjacent;

[0010] A jet module, which is used at least for jet flushing of a processing region of the workpiece, the processing region comprising the second region and the first region;

[0011] Wherein, the workpiece does not chemically react with the electrolyte used by the electrochemical discharge processing module, and the oxide formed by the oxidation of the workpiece can be removed by chemically reacting with the electrolyte, the oxide being formed by the oxidation of the surface layer during the electrochemical discharge processing and / or the laser ablation processing of the workpiece.

[0012] The second aspect of the embodiment of the present application provides an electrochemical discharge-laser-dynamic wet etching composite processing method, which comprises:

[0013] Submerging the workpiece in the electrolyte, and synchronously performing electrochemical discharge processing on a first region of the workpiece, laser ablation processing on a second region of the workpiece, and jet flushing on a processing region of the workpiece, the processing region comprising the second region and the first region, the first region being distributed around the second region, and the first region and the second region being adjacent;

[0014] Wherein, the workpiece does not chemically react with the electrolyte used by the electrochemical discharge processing module, and the oxide formed by the oxidation of the workpiece can be removed by chemically reacting with the electrolyte, the oxide being formed by the oxidation of the surface layer during the electrochemical discharge processing and / or the laser ablation processing of the workpiece.

[0015] The third aspect of the embodiment of the present application provides a use of the electrochemical discharge-laser-dynamic wet etching combined machining system or the electrochemical discharge-laser-dynamic wet etching combined machining method in drilling machining, cutting machining, pin milling machining and forming machining.

[0016] Compared with the prior art, the advantages of the present application include:

[0017] (1) In the hole making process, as the hole depth increases, the machining product is difficult to discharge from the gap, which interrupts the machining process, the jet flow of the tool electrode center electrode hole accelerates the product discharge, which is beneficial to improve the machining speed, but the electrode hole center cannot be etched in time to face the workpiece material, thereby producing a protrusion, which is easy to collide with the feeding electrode to cause short circuit, the coaxial focused laser beam is focused on the protrusion material to melt the protrusion material, and additional hydrogen is also produced, the electrochemical discharge-laser-dynamic wet etching machining system and method provided by the embodiment of the present application improves the discharge frequency, thereby ensuring a stable and efficient machining process.

[0018] (2) The electrochemical discharge-laser-dynamic wet etching machining system and method provided by the embodiment of the present application avoids secondary discharge with the side wall in the product discharge process, which damages the machined surface and ensures the consistency of the hole type and improves the machining precision.

[0019] (3) The electrochemical discharge-laser-dynamic wet etching machining system and method provided by the embodiment of the present application uses a chemical solution having etching effect on SiC oxide as an electrolyte for electrochemical discharge machining, which provides a gas environment for electrochemical discharge machining and synchronously etches the oxide layer generated on the hole wall, thereby improving the surface quality of the inner wall of the hole.

[0020] (4) The electrochemical discharge-laser-dynamic wet etching machining system and method provided by the embodiment of the present application has a synchronous effect of electrochemical discharge, laser ablation and chemical etching, therefore, the high temperature generated by electrochemical discharge and laser ablation can accelerate the etching rate of the oxide layer, the high temperature promotes oxidation and etching effect at the same time, thereby producing selective etching of the oxide layer and improving the etching precision.

[0021] (5) The electrochemical discharge-laser-dynamic wet etching machining system and method provided by the embodiment of the present application keeps the jet flow coaxial with the tool electrode and the focused laser beam, which can continuously cool the machining area and reduce heat accumulation, in addition, has a stronger flushing effect, can update the solution state of the machining area in time, maintains stable discharge at the same time, inhibits the absorption of laser energy by debris and accumulated bubbles, and also maintains a constant etching rate of the machining area.

[0022] (6) The present invention provides an electrochemical discharge-laser-dynamic wet etching processing system and method. The current detection module monitors the current and reacts to the processing status in real time, which can provide a reference for the adjustment of subsequent process parameters and accurately control the drilling time. For example, after the gas film cooling hole of the turbine blade is processed, the blade is lifted to effectively prevent laser damage to the blade back. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of an electrochemical discharge-laser-dynamic wet etching composite hole-making system provided in a typical embodiment of the present invention;

[0024] Figure 2 A schematic diagram of an electrochemical discharge-laser-dynamic wet etching composite hole-making system for making holes in SiC / SiC composite workpieces, provided in a typical embodiment of the present invention;

[0025] Figure 3 , Figure 4 , Figure 5 , Figure 6 These are schematic diagrams illustrating individual hole-making processes: electrochemical discharge, laser ablation, chemical etching, and jet flushing.

[0026] Figure 7 This is a schematic diagram illustrating the evolution of hole patterns during electrochemical discharge machining, laser machining, and electrochemical discharge-laser composite machining processes.

[0027] Figure 8 This is a schematic diagram illustrating the enhanced discharge effect of laser hydrogen production;

[0028] Figure 9 , Figure 10 These are schematic diagrams of selective chemical etching and uniform chemical etching processes, respectively.

[0029] Figure 11 This is a schematic diagram illustrating the improvement effect of jet scouring on electrochemical discharge-laser composite processing;

[0030] Figure 12 , Figure 13 , Figure 14 These are schematic diagrams of current feedback at different drilling times;

[0031] Figure 15 , Figure 16 , Figure 17 , Figure 18 These are schematic diagrams illustrating drilling, cutting, milling, and forming processes performed by the electrochemical discharge-laser-dynamic wet etching composite processing system in a typical embodiment of the present invention. Detailed Implementation

[0032] In view of the shortcomings of the prior art, the inventors of this invention, through long-term research and extensive practice, have proposed the technical solution of this invention. The following will further explain and illustrate this technical solution, its implementation process, and its principles.

[0033] In a typical implementation scheme, to address the issues of low material removal rate when using electrochemical discharge machining to machine deep small holes (holes with a depth-to-diameter ratio of 10 or higher are called deep small holes) on hard and brittle materials that are difficult to machine, inconsistent hole profiles when using laser machining, and the thermal effects of both processes easily leading to high-temperature oxidation of hard and brittle materials, this invention combines electrochemical discharge machining, laser machining, chemical etching, and jet machining to simultaneously act on the hole-making process of hard and brittle materials.

[0034] This invention provides an electrochemical discharge-laser-dynamic wet etching composite processing system, which combines the high precision advantages of electrochemical discharge processing, utilizes laser processing to improve processing efficiency, and employs dynamic chemical solution to selectively etch the oxide layer generated during the processing of hard and brittle materials, while updating the solution state in a timely manner, thereby forming a processing solution with high efficiency, high precision, and high surface quality.

[0035] The present invention provides an electrochemical discharge-laser-dynamic wet etching composite processing system, which can effectively combine electrochemical discharge processing, laser processing and dynamic wet etching by combining an electrochemical discharge processing system, a laser processing system, a chemical solution jetting system and a current detection system, thus laying the process equipment foundation for forming an efficient, high-precision and high-surface-quality electrochemical discharge-laser-dynamic wet etching composite hole-making method.

[0036] The first aspect of this invention provides an electrochemical discharge-laser-dynamic wet etching composite processing system, comprising:

[0037] An electrochemical discharge machining module, which is used at least to perform electrochemical discharge machining on a first region of a workpiece to remove material from the first region of the workpiece;

[0038] A laser processing module, which is at least used to perform laser ablation processing on a second region of the workpiece to remove material from the second region of the workpiece, wherein the first region is distributed around the second region and the first region and the second region are adjacent to each other;

[0039] A jet module, which is at least used to jet-wash the processing area of ​​the workpiece, the processing area including the second area and the first area;

[0040] The workpiece does not chemically react with the electrolyte used in the electrochemical discharge machining module, but the oxide formed by the oxidation of the workpiece can chemically react with the electrolyte and be removed. The oxide is formed by the oxidation of the surface layer of the workpiece during the electrochemical discharge machining and / or the laser ablation process.

[0041] Furthermore, the electrochemical discharge machining module includes an electrolytic cell, a tool electrode, and an auxiliary electrode. The electrolytic cell is used to hold an electrolyte. The tool electrode, the auxiliary electrode, and the workpiece are disposed in the electrolytic cell and in contact with the electrolyte. The tool electrode has a tubular electrode structure and has an electrode hole that extends along its own axis. One end of the tool electrode faces the workpiece. When power is supplied to the auxiliary electrode and the tool electrode, a discharge channel is induced between the end face of the tool electrode facing the workpiece and the workpiece. The heat energy generated by the discharge channel is greater than the ablation threshold of the workpiece material.

[0042] The laser processing module includes a laser, other optical path components, and a focusing lens. The other optical path components are disposed between the laser and the focusing lens. The laser beam emitted by the laser is guided by the other optical path components to the focusing lens and focused by the focusing lens on the second region of the workpiece. The power density of the focal point of the laser beam is greater than the ablation threshold of the workpiece material.

[0043] The jet module includes a chemical solution supply component and a nozzle. The nozzle is connected to the chemical solution supply component, and the chemical solution provided by the chemical solution supply component is sprayed onto the processing area of ​​the workpiece through the nozzle.

[0044] Furthermore, the focusing lens and the nozzle are sequentially arranged above the tool electrode along the axial direction of the tool electrode. The laser beam focused by the focusing lens irradiates the workpiece along the electrode hole inside the tool electrode, and the chemical solution sprayed through the nozzle flows out along the electrode hole inside the tool electrode.

[0045] Furthermore, the central axis of the tool electrode, the central axis of the electrode hole inside the tool electrode, the central axis of the nozzle, and the optical axis of the focusing lens coincide, and the focused laser beam and the jet formed by the chemical solution are coaxial with the tool electrode.

[0046] Furthermore, the tool electrode includes a conductive metal and an insulating layer arranged sequentially from the inside to the outside along its own radial direction, with the conductive metal enclosing and forming the electrode hole.

[0047] Furthermore, the laser processing module also includes a CCD camera, which emits a visible light beam. The visible light beam passes through other optical path components and the focusing lens to form a positioning beam that is coaxial with the focused laser beam.

[0048] Furthermore, the other optical path components include optical lenses and dichroic mirrors, etc.

[0049] Furthermore, the electrolyte and the chemical solution used for jet flushing by the jet module are the same solution. The chemical solution supply component is also connected to the electrolytic cell, and a loop for the chemical solution to circulate is formed between the chemical solution supply component, the nozzle, and the electrolytic cell.

[0050] In a more specific implementation, the electrochemical discharge-laser-dynamic wet etching composite processing system further includes: a motion platform, on which at least the tool electrode, the nozzle, and the focusing lens are disposed, and the motion platform is at least used to drive the tool electrode, the nozzle, and the focusing lens toward the workpiece.

[0051] Furthermore, the electrolytic cell is disposed on the motion platform, and the motion platform is also used to drive the electrolytic cell to move along the x-axis and y-axis of the three-dimensional coordinate system.

[0052] Furthermore, the motion platform is a three-axis motion table.

[0053] In a more specific implementation, the electrochemical discharge-laser-dynamic wet etching composite processing system further includes a current detection module, which is electrically connected to a power supply and is used to detect the current in the conductive path formed by the power supply, the tool electrode, and the auxiliary electrode.

[0054] Furthermore, the current detection module includes an oscilloscope and a current probe, with the oscilloscope electrically connected to the power supply via the current probe.

[0055] A second aspect of this invention provides an electrochemical discharge-laser-dynamic wet etching composite processing method, comprising:

[0056] The workpiece is immersed in an electrolyte, and electrochemical discharge processing is performed on the first region of the workpiece, laser ablation processing is performed on the second region of the workpiece, and jet scouring is performed on the processed region of the workpiece. The processed region includes the second region and the first region, the first region is distributed around the second region, and the first region and the second region are adjacent to each other.

[0057] The workpiece does not chemically react with the electrolyte used in the electrochemical discharge machining module, but the oxide formed by the oxidation of the workpiece can chemically react with the electrolyte and be removed. The oxide is formed by the oxidation of the surface layer of the workpiece during the electrochemical discharge machining and / or the laser ablation process.

[0058] In a more specific implementation, the electrochemical discharge-laser-dynamic wet etching composite processing method specifically includes:

[0059] The workpiece, tool electrode, and auxiliary electrode are placed in an electrolyte, with the tool electrode positioned above the workpiece. Power is supplied to the tool electrode and the auxiliary electrode. A discharge channel is induced between the end face of the tool electrode facing the workpiece and the workpiece. The heat generated by the discharge channel ablates and removes the material in the first region of the workpiece.

[0060] The laser beam is focused on the second region of the workpiece to ablate and remove the material from the second region of the workpiece.

[0061] A chemical solution is sprayed onto the processing area of ​​the workpiece, and the jet formed by the chemical solution washes over the processing area of ​​the workpiece.

[0062] Furthermore, the tool electrode is a tubular electrode structure, and the tool electrode has an electrode hole that runs through it along its own axis. One end of the tool electrode faces the workpiece. The method specifically includes: irradiating the workpiece with a focused laser beam formed after focusing along the electrode hole, and spraying a jet formed by a chemical solution through the electrode hole onto the workpiece. The jet, the focused laser beam, and the tool electrode are coaxial.

[0063] Furthermore, the electrolyte is the same solution used for jet flushing.

[0064] Furthermore, the workpiece is a hard and brittle material that is difficult to machine. Specifically, hard and brittle materials that are difficult to machine include materials containing SiC (such as SiC / SiC composite materials), titanium alloy materials, nickel-based high-temperature alloy materials, etc.

[0065] In a more specific implementation, the electrochemical discharge-laser-dynamic wet etching composite processing method further includes: feeding the tool electrode and the focused laser beam toward the workpiece.

[0066] In a more specific implementation, the electrochemical discharge-laser-dynamic wet etching composite processing method further includes: moving the electrolytic cell containing the electrolyte along the x-axis and y-axis of the three-dimensional coordinate system.

[0067] In a more specific implementation, the electrochemical discharge-laser-dynamic wet etching composite processing method further includes detecting the current in the conductive path formed by the power source, the tool electrode, and the auxiliary electrode.

[0068] In a more specific implementation, the electrochemical discharge-laser-dynamic wet etching composite processing method is implemented based on the electrochemical discharge-laser-dynamic wet etching composite processing system.

[0069] A third aspect of the present invention provides the use of the electrochemical discharge-laser-dynamic wet etching composite processing system or the electrochemical discharge-laser-dynamic wet etching composite processing method in drilling, cutting, milling, and forming processes.

[0070] The following will further explain the technical solution, its implementation process and principle in conjunction with the accompanying drawings and specific implementation examples. Unless otherwise specified, the optical elements such as optical lenses, focusing lenses, dichroic mirrors, lasers, nozzles, auxiliary electrodes, power supplies, oscilloscopes, water chillers, computers, CCD cameras, water pumps, flow meters, rotary valves, filter devices, and three-axis motion stages used in the embodiments of the present invention are all known in the art and can be obtained commercially. Their specific structures and product models are not limited here.

[0071] In a more specific embodiment, an electrochemical discharge-laser-dynamic wet etching composite processing system includes an electrochemical discharge processing module, a laser processing module, and a jet module. The electrochemical discharge processing module is used to perform electrochemical discharge processing on a first region of the workpiece to remove material from the first region of the workpiece. The laser processing module is used to perform laser ablation processing on a second region of the workpiece to remove material from the second region of the workpiece. The jet module is used to jet-wash the processed area of ​​the workpiece. The processed area includes the second region and the first region. The first region is distributed around the second region and the first region is adjacent to the second region. Here, the workpiece is a hard and brittle material that is difficult to process, such as SiC / SiC composite material.

[0072] For details, please refer to Figure 1The electrochemical discharge machining module includes an electrolytic cell 13, an auxiliary electrode 12, a tool electrode 30, a power supply 14, and an oscilloscope 15. The electrolytic cell 13 contains an electrolyte 8. The auxiliary electrode 12, the tool electrode 30, and the workpiece 10 are placed in the electrolytic cell 13 and in contact with the electrolyte 8. The tool electrode 30 is a tubular electrode structure with an electrode hole extending along its own axis inside. The tool electrode 30 is positioned above the workpiece 10 along the z-axis of the three-dimensional coordinate system, with one end of the tool electrode 30 facing the workpiece 10. The auxiliary electrode 12 and the tool electrode 30 are electrically connected to the positive and negative terminals of the power supply 14, respectively, and are configured together to form an electrolytic cell. The positive and negative terminals of the oscilloscope 15 are connected to the positive and negative terminals of the power supply 14, respectively, and are used to monitor the machining current in the conductive path formed by the auxiliary electrode 12, the tool electrode 30, and the power supply 14.

[0073] The laser processing module includes a laser 18, a CCD camera 20, an optical lens 22, a dichroic mirror 23, and a focusing lens 1. The focusing lens 1 is positioned above the tool electrode 30 along the z-axis of the three-dimensional coordinate system. The output beam 19 emitted by the laser 18 is reflected by the dichroic mirror 23 and focused by the focusing lens 1 to form a focused laser beam 2. The focused laser beam 2 passes through the electrode hole inside the tool electrode 30 and irradiates the workpiece 10. The focal point of the focused laser beam 2 acts on the surface of the workpiece 10. The visible beam 21 emitted by the CCD camera 20 passes through the optical lens 22, the dichroic mirror 23, and the focusing lens 1 in sequence and irradiates the surface of the workpiece 10 through the electrode hole of the tool electrode 30 to mark the processing position of the focal point of the focused laser beam 2.

[0074] The jet module includes a chemical solution supply component and a nozzle 4. The chemical solution supply component includes a water tank 24 and a water pump 25. The water tank 24, the water pump 25 and the nozzle 4 are connected in sequence by pipelines. The nozzle 4 is set between the tool electrode 30 and the lens 1 along the z-axis of the three-dimensional coordinate system. The chemical solution 7 in the water tank 24 is ejected through the nozzle 4 to form a jet. The jet ejected from the nozzle 4 passes through the electrode hole inside the tool electrode 30 and acts on the workpiece 10.

[0075] Please refer to the following for details. Figure 1 and Figure 2When the power supply 14 supplies power to the tool electrode 30 and the auxiliary electrode 12, it induces the generation of a discharge channel 11 near the tool electrode 30, thereby converting electrical energy into heat energy to erode the workpiece material (i.e., the material of the first region of the workpiece) directly opposite the end face of the tool electrode 30. The discharge status is monitored in real time on the display screen of the oscilloscope 15. The focused laser beam 2 is focused on the surface of the workpiece 10 along the electrode hole inside the tool electrode 30. The workpiece material (i.e., the material of the second region of the workpiece) directly opposite the electrode hole inside the tool electrode 30 is continuously flushed along the electrode hole inside the tool electrode 30 (the processing area includes the first region and the second region). The processing product 7 is discharged by means of backflow and the processing area is cooled. The tool electrode 30, the jet and the focused laser beam 2 continue to feed towards the workpiece 10, and the material removal process is cyclical, gradually forming a hole.

[0076] Specifically, to achieve the formation of deep small holes on the workpiece and to facilitate the continuous feeding of the tool electrode 30, the jet, and the focused laser beam 2 towards the workpiece 10, the electrochemical discharge machining module also includes a three-axis motion stage. The tool electrode 30, the focusing lens 1, and the nozzle 4 are mounted on the z-axis slide 3 of the three-axis motion stage. The tool electrode 30, the focused laser beam 2, and the jet can move synchronously along the z-axis. The electrolytic cell 13 is mounted on the x and y axis displacement stages (…). Figure 1 Only the y-axis slide 34 is shown in the figure, on which the electrolytic cell 13 can reciprocate along the x and y axes.

[0077] Specifically, the tool electrode 30 is preferably a circular tube electrode. The central axis of the tool electrode 30, the central axis of the electrode hole, the central axis of the nozzle 4, and the optical axis of the focusing lens 1 are preferably coincident, so that the jet is coaxial with the focused laser beam and the tool electrode. Specifically, the focused laser beam and the jet are located inside the tool electrode, and the focused laser beam is located inside the jet.

[0078] More specifically, the tool electrode 30 includes a conductive metal 5 and an insulating layer 6 arranged sequentially from the inside to the outside along its radial direction. The conductive metal 5 encloses and forms the electrode hole. The power supply 14 is specifically electrically connected to the conductive metal 5 of the tool electrode 30. The insulating layer 6 of the tool electrode 30 prevents secondary discharge between the processed product 7 and the tool electrode 30, thereby avoiding damage to the processed surface of the hole. Due to the thermal effect, an oxide layer 9 is generated on the sidewall of the hole. The electrolyte 8 can chemically react with the oxide layer 9, etching it away to obtain a smooth hole wall. More specifically, the conductive metal 5 inside the tool electrode 30 can be made of at least one of stainless steel, tungsten, brass, copper, and titanium alloy, but is not limited to these. Specifically, the auxiliary electrode 12 can be made of at least one of graphite and calomel, but is not limited to these. Specifically, the electrolytic cell 13 can be made of acrylic acid, etc. The power supply 14 can be a DC power supply.

[0079] Please refer to it again. Figure 1 To prevent the tool electrode 30 from wobbling during the machining process, the electrochemical discharge machining module may also include an electrode clamping device 28 and a guide sleeve 29. The guide sleeve 29 is fixed below the electrode clamping device 28 along the z-axis. The electrode clamping device 28 clamps the tool electrode 30. The part of the tool electrode 30 near the workpiece 10 passes through the guide sleeve 29 and extends out from inside the guide sleeve 29.

[0080] For details, please refer to the following document again. Figure 1 The laser processing module may further include a water chiller 16 and a computer 17. The water chiller 16 is thermally connected to the laser 18 and is used to cool the laser 18. The computer 17 is connected to the laser 18 and is used to adjust the working state / parameters of the laser 18. For example, the laser 18 may be a nanosecond laser. Both the water chiller 16 and the computer 17 are known in the art. The water chiller 16 can also be replaced with other functional mechanisms capable of regulating the temperature of the laser; no specific limitations are made here. The numerical control program contained in the computer 17 is also known in the art.

[0081] Specifically, the chemical solution 7 and the electrolyte 8 used to form the jet can be the same solution. The solvent type and mass concentration of both the chemical solution 7 and the electrolyte 8 are identical. The solvent for both the chemical solution 7 and the electrolyte 8 can be at least one of NaOH, KOH, and HCl, and the mass concentration of both can be 50-200 g / L. Please refer again. Figure 1 The water tank 24 can be connected to the electrolytic cell 13. A first flow meter 26 and a first switch valve 27 are installed on the pipeline connecting the water pump 25 and the nozzle 4. A filter device 33 is also installed between the water tank 24 and the electrolytic cell 13. The water tank 24, the electrolytic cell 13 and the filter device 33 are connected. A second flow meter 31 and a second switch valve 32 are installed on the pipeline connecting the electrolytic cell 13 and the filter device 33, thereby forming a loop between the water tank 24 and the electrolytic cell 13 for the chemical solution 7 / electrolyte 8 to circulate. Specifically, the water pump 25 draws chemical solution 7 from the water tank 24, and the inlet flow rate is adjusted by the first flow meter 26. The chemical solution 7 enters the nozzle 4 through the first switch valve 27, and then enters the electrode hole of the tool electrode 30, and is sprayed onto the processing area of ​​the workpiece to form a jet flushing processing area. An opening is provided at the lower end of one side of the electrolytic cell tank 13, which is connected to the second flow meter 31 and the second switch valve 32 through a pipeline. The electrolyte output from the electrolytic cell tank 13 enters the filter device 33 to filter out impurities, and then flows back into the water tank 24 for recycling. The first switch valve 27 and the second switch valve 32 are kept in the normally open state, and the first flow meter 26 and the second flow meter 31 adjust the inlet flow rate and the outlet flow rate to be consistent.

[0082] In a typical implementation case, the electrochemical discharge-laser-dynamic wet etching composite processing method using the aforementioned electrochemical discharge-laser-dynamic wet etching composite processing system specifically includes the following processes:

[0083] (1) In the submerged electrolytic cell 13, after the tool electrode 30 and the auxiliary electrode 12 are powered by the power supply 14, the electrolyte undergoes an electrochemical reaction around the tool electrode 30 and the auxiliary electrode 12. Hydrogen evolution reaction occurs near the tool electrode 30 to generate hydrogen bubbles. The hydrogen bubbles gather to form a gas film that wraps around the tool electrode 30. When the electric field strength exceeds that of the gas film, breakdown occurs, generating plasma. The plasma thermal energy is used to erode the material in the first region of the workpiece, and the shape of the tool electrode 30 is copied.

[0084] (2) The output beam 19 emitted by the laser 18 is reflected by the dichroic mirror 23 and focused above the nozzle 4 by the focusing lens 1 to form a focused laser beam 2. The focused laser beam 2 passes through the electrode hole inside the tool electrode 30 and irradiates the workpiece 10. The focal point of the focused laser beam 2 acts on the surface of the workpiece 10, melting the workpiece material directly opposite the electrode hole of the tool electrode 30. It should be noted that the focal length of the focused laser beam 2 needs to be greater than the axial length of the tool electrode 30 to ensure that the focal point of the focused laser beam 2 is located on the workpiece. Specifically, since sufficient drilling depth is required, the length of the tool electrode 30 needs to be long enough, at least greater than 10 mm, so that the tool electrode 30 can simultaneously clamp and extend into the machining hole. Since the laser beam moves coaxially with the tool electrode 30, it is focused above the tool electrode 30. Therefore, the length (focal length) of the focused laser beam 2 needs to be at least greater than the length of the tool electrode 30 to ensure that the focal point falls on the workpiece. Based on the convenience of clamping and machining, the length of the tool electrode 30 is relatively long. Therefore, it is recommended that the focal length exceed 30 mm, preferably more than 100 mm.

[0085] (3) The chemical solution 7 pumped from the water tank 24 passes through the nozzle 4 and flows out along the electrode hole in the tool electrode 30 to form a jet coaxial with the tool electrode 30 and the focused laser beam 2, which limits the range of the heat-affected zone generated by the laser and the discharge, and refreshes the solution (i.e. electrolyte) in the processing gap.

[0086] (4) The tool electrode 30 and the focused laser beam are fed into the workpiece 10 simultaneously to gradually form a deep hole. The oscilloscope 15 continuously monitors the changes in the processing current provided by the power supply 14. When the frequency of the discharge current decreases significantly or there is no discharge current, the through hole processing is completed.

[0087] Specifically, the correspondence between processing current and processing state is as follows: Figures 12-14As shown, chip removal is good in the early stage of drilling, and the oscilloscope shows that the discharge current frequency and peak value are low. As the machining depth increases, poor chip removal leads to a deterioration of the discharge condition, and the discharge current peak value and frequency increase rapidly, even showing a continuous discharge waveform. When the hole is penetrated, the debris is discharged from the bottom of the hole, and the discharge area decreases instantly until it disappears. The current waveform shows the rapid decrease of the current frequency until there is no discharge current.

[0088] Please see Figure 3 , Figure 3 This is a schematic diagram of hole making using electrochemical discharge processing. In electrochemical discharge machining, the workpiece 10 and the auxiliary electrode 12 are immersed in the electrolyte 8. Under the action of the power supply 14, an electrochemical reaction occurs. An oxidation reaction occurs at the anode and a reduction reaction occurs at the cathode. Hydrogen ions in the water are attracted to the negative electrode and gain electrons to produce hydrogen gas. Hydroxide ions are attracted to the negative electrode and lose electrons to produce oxygen gas. Hydrogen bubbles 35 are continuously generated on the exposed conductive metal end face of the cathode tool electrode 30. They then accumulate into a gas film and are broken down under the action of a strong electric field to generate a plasma discharge channel 11. As the tool electrode 30 approaches the workpiece 10, the heat energy generated by the discharge channel 11 melts or vaporizes the material, creating pits 36 on the surface of the workpiece 10. The pits stack up to form the final contour.

[0089] Please see Figure 4 , Figure 4 This is a schematic diagram of laser ablation for creating holes. The focal energy density of the focused laser beam 2 is the highest. After exceeding the melting or boiling point of the material, it melts or vaporizes the material, and similar pits 36 formed by discharge etching are also generated at the focal point.

[0090] Please see Figure 5 , Figure 5 This is a schematic diagram of a chemical etching process for creating holes. Taking SiC / SiC composite material as an example, SiC / SiC composite material has strong chemical resistance and is not easily corroded. However, the SiC oxide formed by oxidation reaction under high temperature can react chemically with strong acids (such as hydrofluoric acid) or strong bases (NaOH) and be corroded. In the etching solution, SiC / SiC composite material does not react with the etching solution, while oxide layer 9 is etched and dissolved. In order to reduce the damage of fluorine-containing substances to the environment and personnel, alkaline solutions are preferred as etching solutions.

[0091] Please see Figure 6 , Figure 6 This is a schematic diagram of the jet flushing process for hole making. The function of jet flushing is, on the one hand, to flush the processing area and remove the processing product 7, thereby reducing the probability of bad discharge and inhibiting the absorption of laser energy by the processing product 7 and accumulated bubbles. On the other hand, jet flushing can also cool the processing area and reduce the expansion of the heat-affected zone 37.

[0092] Figure 7This diagram illustrates the evolution of hole patterns in electrochemical discharge machining, laser machining, and electrochemical discharge-laser composite machining. To achieve higher machining efficiency and surface quality by utilizing a central jet scouring process, the conductive metal 5 inside the tool electrode 30 is perforated. The probability of discharge at the perforated location is very low, resulting in slower material removal from the workpiece in the area corresponding to the electrode hole. Therefore, a protrusion forms at the center of the workpiece corresponding to the electrode hole of the workpiece electrode 30 (i.e., the aforementioned second region). When the tool electrode 30 continues to feed towards the workpiece 10, the conductive metal 5 is prone to colliding with the protrusion, causing a short circuit and interrupting the machining process. In laser machining, as the machining depth increases, the difficulty of chip removal increases, and the chips absorb laser energy during removal, leading to a gradual attenuation of the laser energy acting on the workpiece 10. This results in a gradual increase in the hole taper, and even with layered scanning machining, taper issues still occur. The electrochemical discharge-laser composite machining provided by the present invention uses the tool electrode 30 to process the workpiece material corresponding to the edge (surrounding) of the electrode hole (i.e., the material of the first region of the workpiece), and uses the laser to process the center material corresponding to the electrode hole (i.e., the material of the second region of the workpiece). This allows the electrothermal energy and the laser to compensate for each other, thereby improving the processing efficiency and the contour accuracy of the hole.

[0093] Specifically, in this invention, the focused laser beam and jet are located inside the tool electrode. The jet at the center of the tool electrode hole directly scours the machining area to improve chip removal. However, since there is no current density in the center hole of the tool electrode, a central bulge appears in the material during drilling (e.g., ...). Figure 7 As shown in the figure, the energy loss is compensated by the focused laser beam, which can eliminate the workpiece material directly opposite the center hole of the tool electrode. Therefore, the coaxial arrangement of the tool electrode, focused laser beam, and jet can synchronously enhance chip removal and compensate for energy loss, making the hole machining process more stable.

[0094] Figure 8 The diagram illustrates the enhanced discharge effect of laser hydrogen production. In addition to the hydrogen evolution reaction at the tool electrode 30, which serves as the cathode in the electrolytic cell 13, the focused laser beam 2 uses high temperature to decompose the water-based electrolyte 8 to generate hydrogen bubbles 35. The generated position is exactly located on the end face of the tool electrode 30 facing the workpiece 10. More bubbles 35 accelerate the formation of the gas film, increase the discharge probability, and increase the efficiency of material removal by discharge.

[0095] Figure 9 , Figure 10These are schematic diagrams illustrating the processes of selective chemical etching and uniform chemical etching, respectively. The heat energy generated by discharge and ablation is concentrated in the workpiece area directly opposite the end face of the tool electrode 30. Therefore, compared to the oxide layer 9, the high temperature accelerates the chemical etching rate of the workpiece material directly opposite the end face of the tool electrode 30. The oxide layer 9 is rapidly etched during its formation, which in turn affects the formation of the oxide layer 9. That is, after the oxide layer 9 is thinned by selective etching induced by high temperature, it is etched a second time in the immersed electrolyte 8. In addition, the continuous flushing of the processing area by the jet rapidly removes the processing product 7, stabilizing the mass concentration of the electrolyte 8 and making the etching effect more uniform.

[0096] Figure 11 This diagram illustrates the improvement effect of jet flushing on electrochemical discharge-laser composite processing. Jet flushing not only washes away the processed product 7, but also removes some discrete bubbles 35 that have not formed a gas film, inhibiting their absorption of laser energy. It also reduces the secondary discharge caused by bridging between the processed product 7 and discrete bubbles 35 within the narrow discharge gap, thus preventing the discharge state from deteriorating. Furthermore, jet flushing has a deionization effect; after the material is etched away in the plasma discharge channel 11, it compresses and interferes with channel expansion, reducing thermal damage to the material from excessive discharge.

[0097] Figure 12 , Figure 13 , Figure 14 The diagrams show the current feedback at different drilling stages. In the initial machining stage, a discharge occurs between the conductive metal 5 and the workpiece 10. The generated machining products 7 and bubbles 35 are easily expelled from the machining gap, resulting in minimal secondary discharge. This is reflected on the oscilloscope 15 screen as regular, small current fluctuations. As the tool electrode 30 continues to feed and machining reaches a certain depth, the expulsion distance of the machining products 7 and bubbles 35 increases, meaning their residence time within the machining gap lengthens. The accumulated bubbles 35 and products 7 lead to an increased discharge frequency and worsened operating conditions. The oscilloscope 15 simultaneously reflects more current fluctuations and higher current peaks. When the hole penetrates, the pressure within the machining gap drops sharply, and the volumetric flow rate of the machining products 7 decreases instantaneously. The central jet easily detaches the newly generated bubbles 35 from the conductive metal 5, resulting in minimal discharge. This is reflected on the oscilloscope 15 as fewer low-peak current waveforms.

[0098] Figure 15 , Figure 16 , Figure 17 , Figure 18This diagram illustrates the application extension of the electrochemical discharge-laser-dynamic wet etching composite processing technology provided by this invention. Drilling is the most complex process, with narrow processing gaps. Especially after reaching a certain depth, drilling negatively impacts discharge, laser, and chemical etching. By optimizing numerous process parameters (including electrical parameters (voltage, frequency, duty cycle), laser parameters (single pulse energy, spot overlap rate), and jet parameters (electrolyte type, ratio, jet pressure), etc.), drilling can achieve good processing results, allowing for further expansion of the process. For example, in cutting, material is removed by side discharge from the tool electrode 30, thus eliminating the need for the insulating layer 6. Similarly, in milling, during side milling, the tool electrode 30 feeds along the y-axis to the workpiece 10, also using side discharge. To prevent secondary damage to the milling groove surface from the electrode tip, an insulating layer 6 is provided on the end face of the tool electrode 30. The significant advantage of electrical discharge machining (EDM) is that it can generate complex contours with high precision. It can produce tool electrodes 30 with complex shapes, set an insulating layer 6 on the outside of the electrode, and then directly copy the electrode shape onto the workpiece 10 to form a complex contour, which is called forming machining.

[0099] It should be noted that the oxide layer formed during the processing of SiC / SiC composite materials can be etched away with an alkaline solution, while the oxide layer formed during the processing of hard and brittle materials such as titanium alloys and nickel-based high-temperature alloys can be etched with an appropriate electrolyte solution. That is, the corresponding electrolyte solution is different for the oxides formed during the processing of workpieces of different materials.

[0100] It should be understood that the above embodiments are merely illustrative of the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. An electrochemical discharge-laser-dynamic wet etching composite processing system, characterized in that, include: An electrochemical discharge machining module, which is used at least to perform electrochemical discharge machining on a first region of a workpiece to remove material from the first region of the workpiece; A laser processing module, which is at least used to perform laser ablation processing on a second region of the workpiece to remove material from the second region of the workpiece, wherein the first region is distributed around the second region and the first region and the second region are adjacent to each other; A jet module, which is at least used to jet-wash the processing area of ​​the workpiece, the processing area including the second area and the first area; The workpiece does not chemically react with the electrolyte used in the electrochemical discharge machining module, but the oxide formed by the oxidation of the workpiece can chemically react with the electrolyte and be removed. The oxide is formed by the oxidation of the surface layer of the workpiece during the electrochemical discharge machining and / or the laser ablation process.

2. The electrochemical discharge-laser-dynamic wet etching composite processing system according to claim 1, characterized in that: The electrochemical discharge processing module includes an electrolytic cell (13), a tool electrode (30), and an auxiliary electrode (12). The electrolytic cell (13) is used to hold an electrolyte (8). The tool electrode (30), the auxiliary electrode (12), and the workpiece (10) are disposed in the electrolytic cell (13) and in contact with the electrolyte (8) in the electrolytic cell (13). The tool electrode (30) is a tubular electrode structure. The tool electrode (30) has an electrode hole that runs through it along its own axis. The opening of one end of the tool electrode (30) faces the workpiece (10). When the auxiliary electrode (12) and the tool electrode (30) are powered by a power source (14), a discharge channel (11) is induced between the end face of the tool electrode (30) facing the workpiece (10) and the workpiece (10). The heat energy generated by the discharge channel (11) is greater than the ablation threshold of the workpiece (10) material. The laser processing module includes a laser (18), other optical path components and a focusing lens (1). The other optical path components are disposed between the laser (18) and the focusing lens (1). The laser beam emitted by the laser (18) is guided by the other optical path components to the focusing lens (1) and focused by the focusing lens (1) on the second region of the workpiece (10). The power density of the focal point of the laser beam is greater than the ablation threshold of the workpiece (10) material. The jet module includes a chemical solution supply component and a nozzle (4). The nozzle (4) is connected to the chemical solution supply component, and the chemical solution (7) provided by the chemical solution supply component is sprayed through the nozzle (4) onto the processing area of ​​the workpiece (10).

3. The electrochemical discharge-laser-dynamic wet etching composite processing system according to claim 2, characterized in that: The focusing lens (1) and the nozzle (4) are arranged sequentially above the tool electrode (30) along the axial direction of the tool electrode (30). The laser beam focused by the focusing lens (1) irradiates the workpiece (10) along the electrode hole inside the tool electrode (30). The chemical solution (7) sprayed through the nozzle (4) rushes out along the electrode hole inside the tool electrode (30).

4. The electrochemical discharge-laser-dynamic wet etching composite processing system according to claim 3, characterized in that: The central axis of the tool electrode (30), the central axis of the electrode hole inside the tool electrode (30), the central axis of the nozzle (4), and the optical axis of the focusing lens (1) are coincident. The focused laser beam and the jet formed by the chemical solution (7) are coaxial with the tool electrode (30).

5. The electrochemical discharge-laser-dynamic wet etching composite processing system according to claim 2, 3, or 4, characterized in that: The tool electrode (30) includes a conductive metal (5) and an insulating layer (6) arranged sequentially from the inside to the outside along its own radial direction, and the conductive metal (5) surrounds to form the electrode hole.

6. The electrochemical discharge-laser-dynamic wet etching composite processing system according to claim 5, characterized in that: The laser processing module also includes a CCD camera, which emits a visible beam. The visible beam passes through other optical path components and the focusing lens (1) to form a positioning beam that is coaxial with the focused laser beam.

7. The electrochemical discharge-laser-dynamic wet etching composite processing system according to claim 5, characterized in that: The chemical solution supply component is also connected to the electrolytic cell (13). A loop is formed between the chemical solution supply component, the nozzle (4), and the electrolytic cell (13) for the chemical solution to circulate. The electrolyte and the chemical solution used for jet flushing by the jet module are the same solution.

8. The electrochemical discharge-laser-dynamic wet etching composite processing system according to claim 2, characterized in that, Also includes: The motion platform is provided with at least the tool electrode (30), the nozzle (4) and the focusing lens (1), and the motion platform is used to drive the tool electrode (30), the nozzle (4) and the focusing lens (1) to feed toward the workpiece.

9. The electrochemical discharge-laser-dynamic wet etching composite processing system according to claim 8, characterized in that: The electrolytic cell (13) is mounted on the motion platform, which is also used to drive the electrolytic cell (13) to move along the x-axis and y-axis of a three-dimensional coordinate system.

10. The electrochemical discharge-laser-dynamic wet etching composite processing system according to claim 9, characterized in that: The motion platform is a three-axis motion table.

11. The electrochemical discharge-laser-dynamic wet etching composite processing system according to claim 2, characterized in that, Also includes: A current detection module is electrically connected to a power supply (14) and is used to detect the current in the conductive path formed by the power supply (14), the tool electrode (30), and the auxiliary electrode (12).

12. The electrochemical discharge-laser-dynamic wet etching composite processing system according to claim 11, characterized in that: The current detection module includes an oscilloscope (15) and a current probe, wherein the oscilloscope (15) is electrically connected to the power supply (14) via the current probe.

13. A composite processing method of electrochemical discharge-laser-dynamic wet etching, characterized in that, include: The workpiece (10) is immersed in the electrolyte (8), and the first region of the workpiece (10) is simultaneously subjected to electrochemical discharge processing, the second region of the workpiece (10) is subjected to laser ablation processing, and the processed area of ​​the workpiece (10) is subjected to jet flushing. The processed area includes the second region and the first region, the first region is distributed around the second region, and the first region and the second region are adjacent to each other. Wherein, the workpiece does not chemically react with the electrolyte used in the electrochemical discharge machining, but the oxide formed by the oxidation of the workpiece can chemically react with the electrolyte and be removed. The oxide is formed by the oxidation of the surface layer of the workpiece during the electrochemical discharge machining and / or the laser ablation process.

14. The electrochemical discharge-laser-dynamic wet etching composite processing method according to claim 13, characterized in that, include: The workpiece (10), tool electrode (30) and auxiliary electrode (12) are placed in electrolyte (8). The tool electrode (30) is located above the workpiece (10). Power is supplied to the tool electrode (30) and the auxiliary electrode (12) by power supply (14). A discharge channel (11) is induced between the end face of the tool electrode (30) facing the workpiece (10) and the workpiece (10). The heat energy generated by the discharge channel (11) ablates and removes the material in the first region of the workpiece (10). The laser beam is focused on the second region of the workpiece (10) to ablate and remove the material in the second region of the workpiece (10); A chemical solution (7) is sprayed onto the processing area of ​​the workpiece (10) to flush the processing area of ​​the workpiece (10) with a jet of the chemical solution (7).

15. The electrochemical discharge-laser-dynamic wet etching composite processing method according to claim 14, characterized in that: The tool electrode (30) is a tubular electrode structure. The tool electrode (30) has an electrode hole that runs through it along its own axis. The opening of one end of the tool electrode (30) faces the workpiece (10). Furthermore, the electrochemical discharge-laser-dynamic wet etching composite processing method specifically includes: irradiating the workpiece (10) with a focused laser beam formed after focusing along the electrode hole, and spraying the jet formed by the chemical solution (7) through the electrode hole onto the workpiece (10), wherein the jet, the focused laser beam and the tool electrode (30) are coaxial.

16. The electrochemical discharge-laser-dynamic wet etching composite processing method according to claim 14, characterized in that: The electrolyte (8) is the same solution as the chemical solution (7) used for jet flushing.

17. The electrochemical discharge-laser-dynamic wet etching composite processing method according to claim 14, characterized in that: The workpiece (10) is a hard and brittle material that is difficult to process.

18. The electrochemical discharge-laser-dynamic wet etching composite processing method according to claim 15, characterized in that, Also includes: The tool electrode and the focused laser beam are fed toward the workpiece (10).

19. The electrochemical discharge-laser-dynamic wet etching composite processing method according to claim 15, characterized in that, Also includes: The electrolytic cell (13) containing the electrolyte is moved along the x-axis and y-axis of a three-dimensional coordinate system.

20. The electrochemical discharge-laser-dynamic wet etching composite processing method according to claim 14, characterized in that, Also includes: The current in the conductive path formed by the power source (14), the tool electrode (30), and the auxiliary electrode (12) is detected.

21. The electrochemical discharge-laser-dynamic wet etching composite processing method according to claim 14, characterized in that: The electrochemical discharge-laser-dynamic wet etching composite processing method is implemented based on the electrochemical discharge-laser-dynamic wet etching composite processing system described in any one of claims 1-12.

22. The use of the electrochemical discharge-laser-dynamic wet etching composite processing system as described in any one of claims 1-12 or the electrochemical discharge-laser-dynamic wet etching composite processing method as described in any one of claims 13-21 in drilling, cutting, milling, and forming processes.

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