A coaxial laser and jet electrolysis composite machining system

Abstract

This invention discloses a coaxial laser and jet electrolysis composite machining system, belonging to the field of special machining technology, which can solve the problem of the high difficulty of laser and electrolysis composite machining of precision micro-holes in the prior art. The system includes: a laser unit, an output optical fiber, a machining head, a liquid supply unit, and a first power supply; the laser unit provides a laser beam to the output optical fiber; the machining head is provided with a laser channel, and the output optical fiber is disposed within the laser channel for transmitting the laser beam to the area to be machined on the workpiece; a conductive structure is coaxially disposed on the outer side of the output optical fiber; a liquid channel is provided on the machining head, and the liquid channel is connected to the nozzle of the machining head; the liquid supply unit provides electrolyte to the liquid channel, so that the electrolyte is coaxially jetted from the gap between the nozzle sidewall and the conductive structure into the area to be machined on the workpiece; the anode of the first power supply is connected to the workpiece, and the cathode of the first power supply is connected to the conductive structure. This invention is used for laser and electrolysis composite machining.

Description

Technical Field

[0001] This invention relates to a coaxial laser and jet electrolysis composite processing system, belonging to the field of special processing technology. Background Technology

[0002] High aspect ratio micro-hole structures are widely used in core components of aerospace, mold making, and precision instruments. Their machining accuracy and surface quality directly affect the performance and lifespan of components in extreme working environments. Micro-hole diameters are typically less than 1 mm, with aspect ratios greater than 10. The widespread use of difficult-to-machine materials such as high-temperature alloys and titanium alloys presents challenges to precision machining methods for high aspect ratio micro-holes. Mechanical drilling is limited by the hardness and rigidity of micro-drill bits, resulting in tool wear and making it difficult to meet the precision machining requirements of high aspect ratio micro-holes. Laser processing focuses a high-energy laser beam onto the workpiece area to be processed, offering advantages such as high processing efficiency and strong material adaptability. However, as the laser drilling depth increases, the plasma generated during laser processing is difficult to expel, and the plasma shielding effect leads to a sharp decrease in laser energy utilization. Consequently, the depth of laser-machined micro-holes is typically difficult to exceed 20 mm, and recast layers, microcracks, and heat-affected zones are prone to exist around the processed area. Electrical discharge machining (EDM) can perform invasive machining on conductive materials, with a maximum machining rate of 60 mm / min for deep small holes. However, EDM can cause defects such as recast layers and microcracks on the surface of microholes, and it is difficult to machine non-conductive materials.

[0003] Electrolytic machining removes material through electrochemical anodic dissolution, offering advantages such as no tool wear, high-quality machined surfaces, and the absence of recast layers and microcracks. Tube electrode electrolytic machining uses a hollow metal tube as the tool cathode. The electrolyte is ejected from the tube and exits the machining area along the pores between the outer wall of the tube electrode and the inner wall of the machining hole, facilitating the removal of machining products and heat from the machining gap. Continuous feed of the tube electrode enables invasive deep hole machining. However, the feed rate of the tool electrode in tube electrode electrolytic machining is typically less than 2–3 mm / min, and the current density in the machining area is mainly located below the cross-section of the metal tube, causing a central bulge in the machining area. This makes the machining area prone to short circuits, leading to ablation and damage to the tool electrode tip, affecting machining stability and accuracy consistency.

[0004] To achieve high-quality, high-aspect-ratio small-hole machining, a laser-electrode electrolytic composite machining technology has been proposed. The tool electrode can simultaneously serve as both the laser transmission fiber and the electrolytic machining cathode, enabling the laser and electrochemical energy fields to act synchronously on the machining area. This composite process combines the advantages of laser machining (good material adaptability and high processing efficiency) with the advantages of tube electrode electrolytic machining (good surface quality and large processing depth), achieving high-quality, high-efficiency machining of deep small holes, with a processing efficiency nearly doubled compared to tube electrode electrolytic machining. However, this process transmits the laser beam through total internal reflection at the electrolyte jet boundary, which is limited by the electrolyte breakdown threshold, cavitation effect, and laser energy absorption coefficient in solution, limiting the use of low-power-density green lasers. Furthermore, the tool electrode structure is relatively complex, requiring the electrolyte to flow through the center of the tool electrode to the machining area, resulting in a tool electrode diameter typically greater than 1 mm, leading to larger-diameter holes and making it difficult to meet the requirements of micro-hole machining. The laser is focused at the tool electrode inlet by a focusing lens, resulting in difficult coupling, low efficiency, and the high-power-density laser focus shift easily damaging the composite tool electrode, affecting machining. Summary of the Invention

[0005] This invention provides a coaxial laser and jet electrolysis composite machining system, which can solve the problem of the high difficulty of laser and electrolysis composite machining of precision micro-holes in the prior art.

[0006] This invention provides a coaxial laser and jet electrolysis composite processing system, the system comprising: a laser unit, an output optical fiber, a processing head, a liquid supply unit, and a first power supply;

[0007] The laser unit is used to provide a laser beam to the output optical fiber;

[0008] The processing head is provided with a laser channel, and the output optical fiber is disposed in the laser channel for transmitting the laser beam to the processing area of ​​the workpiece.

[0009] A conductive structure is coaxially arranged on the outer side of the output optical fiber;

[0010] The processing head is provided with a liquid channel, which is connected to the nozzle of the processing head. The liquid supply unit is used to provide electrolyte into the liquid channel so that the electrolyte is coaxially jetted from the gap between the nozzle sidewall and the conductive structure into the processing area of ​​the workpiece.

[0011] The anode of the first power source is connected to the workpiece, and the cathode of the first power source is connected to the conductive structure.

[0012] Optionally, the system further includes a second power source; an annular hollow front cathode is installed on the sidewall of the nozzle;

[0013] The anode of the second power supply is connected to the workpiece, and the cathode of the second power supply is connected to the front cathode;

[0014] The electrolyte is coaxially jetted into the processing area of ​​the workpiece from the gap between the front cathode and the conductive structure.

[0015] Optionally, the conductive structure is a tubular electrode coaxially mounted on the output optical fiber or a metal coating covering the output optical fiber.

[0016] Optionally, the output optical fiber is a bare optical fiber.

[0017] Optionally, the conductive structure and the output optical fiber are coaxially fixed to form a composite optical fiber electrode;

[0018] The processing head is also provided with a guide block; the guide block is used to fix and clamp the composite optical fiber electrode and guide it.

[0019] Optionally, a rotary sealing module is provided on the outer side of the guide block, and the rotary sealing module is sealed to the guide block for driving the composite optical fiber electrode to rotate.

[0020] Optionally, the laser unit includes a laser, an input optical fiber, and a coupling module;

[0021] The laser is used to emit a laser beam;

[0022] The input optical fiber connects the laser and the coupling module, and is used to deliver the laser beam to the coupling module;

[0023] The coupling module is used to couple the laser beam into the output optical fiber.

[0024] Optionally, the laser is a nanosecond pulsed fiber laser or a nanosecond pulsed solid-state laser;

[0025] The laser beam emitted by the laser has a wavelength of 532nm or 1064nm.

[0026] Optionally, the output optical fiber is a quartz optical fiber or a glass optical fiber.

[0027] Optionally, the diameter of the output optical fiber is 0.1 mm to 0.6 mm.

[0028] The beneficial effects that this invention can produce include:

[0029] The coaxial laser and jet electrolysis composite machining system provided by this invention has the advantages of comprehensively utilizing the advantages of electrolysis machining's good surface quality and laser machining's high material removal speed, as well as the effect of laser assistance in promoting the efficiency and localization of electrochemical machining. It synchronously transmits a high-energy-density laser beam and an electrochemical energy field to the front-end processing area, achieving efficient material removal. Compared with existing laser and liquid-core fiber optic electrode electrolysis composite machining, this invention achieves the separation of the laser and the electrolyte, avoiding the limitations of water-assisted laser machining processes that use a 532nm green laser due to laser attenuation in liquid environments, and the limitations of high-energy-density lasers easily penetrating liquids, leading to reduced energy utilization and processing quality. It improves the reliability of laser-tool electrode coupling, reduces the diameter of the tool electrode, and is beneficial for realizing laser-electrolysis composite machining of precision micro-holes. Attached Figure Description

[0030] Figure 1 A schematic diagram of the coaxial laser and jet electrolysis composite processing system provided in an embodiment of the present invention.

[0031] List of components and reference numerals:

[0032] 1. Workpiece; 2. Front cathode; 3. Liquid supply unit; 4. Rotary sealing module; 5. Processing head; 6. Laser; 7. Input fiber optic cable; 8. Coupling module; 9. Output fiber optic cable; 10. Tubular electrode; 11. Guide block. Detailed Implementation

[0033] The present invention will now be described in detail with reference to the embodiments, but the present invention is not limited to these embodiments.

[0034] This invention provides a coaxial laser and jet electrolysis hybrid processing system, such as... Figure 1 As shown, the system includes: a laser unit, an output optical fiber 9, a processing head 5, a liquid supply unit 3, and a first power supply; the laser unit is used to provide a laser beam to the output optical fiber 9; the processing head 5 is provided with a laser channel, and the output optical fiber 9 is disposed in the laser channel to transmit the laser beam to the processing area of ​​the workpiece 1; a conductive structure is coaxially disposed on the outside of the output optical fiber 9; the processing head 5 is provided with a liquid channel, which is connected to the nozzle of the processing head 5; the liquid supply unit 3 is used to provide electrolyte into the liquid channel so that the electrolyte is coaxially jetted from the gap between the nozzle sidewall and the conductive structure into the processing area of ​​the workpiece 1; the anode of the first power supply is connected to the workpiece 1, and the cathode of the first power supply is connected to the conductive structure.

[0035] refer to Figure 1As shown, the laser unit may include a laser 6, an input optical fiber 7, and a coupling module 8. The laser 6 emits a laser beam; the input optical fiber 7 connects the laser 6 and the coupling module 8, and is used to transport the laser beam to the coupling module 8; the coupling module 8 is used to couple the laser beam into the output optical fiber 9. This structure enables low-loss transmission of a high-energy laser beam from the laser 6 to the processing area, allowing for high-speed removal of material from the central processing area via laser processing. The laser 6 used in this invention includes, but is not limited to, nanosecond pulsed fiber lasers and nanosecond pulsed solid-state lasers, with wavelengths including 532 nm and 1064 nm.

[0036] In this embodiment of the invention, the output optical fiber 9 is a bare optical fiber, specifically a quartz optical fiber or a glass optical fiber, with a diameter of 0.1 mm to 0.6 mm.

[0037] The conductive structure can be a tubular electrode 10 coaxially mounted on the output optical fiber 9 or a metal coating covering the output optical fiber 9. The tubular electrode 10 can be a metal capillary. The metal capillary can be made of conductive metal materials such as stainless steel, brass, or titanium, with a wall thickness of 0.1–0.5 mm, and the outer wall of the metal capillary is insulated with an insulation layer thickness of 0.01–0.05 mm.

[0038] The electrolytes used in this invention include, but are not limited to, neutral salt solutions such as NaNO3 and NaCl, acidic solutions such as H2SO4, or a mixture of both.

[0039] Further reference Figure 1 As shown, the system also includes a second power source; an annular hollow front cathode 2 is installed on the side wall of the nozzle; the anode of the second power source is connected to the workpiece 1, and the cathode of the second power source is connected to the front cathode 2; the electrolyte is coaxially jetted into the processing area of ​​the workpiece 1 from the gap between the front cathode 2 and the conductive structure.

[0040] The conductive structure and the output optical fiber 9 are coaxially fixed to form a composite optical fiber electrode; a guide block 11 is also provided on the processing head 5; the guide block 11 is used to fix and clamp the composite optical fiber electrode and guide it. A rotary sealing module 4 is provided on the outside of the guide block 11, and the rotary sealing module 4 is sealed to the guide block 11 to drive the composite optical fiber electrode to rotate.

[0041] In this embodiment of the invention, after the laser beam is emitted from the laser 6, it is coupled, collimated, expanded and focused by an optical fiber and then input into the coaxial output optical fiber 9 embedded in the tubular electrode 10, or the laser beam is coupled into the coaxial output optical fiber 9 embedded in the tubular electrode 10 by a coupling device, and then the laser is transmitted to the processing area through the output optical fiber 9.

[0042] The coaxial composite fiber electrode is composed of an output fiber 9 and a metal capillary, or a metal-coated fiber. Specifically, a tubular metal capillary cathode or a metal coating is coaxially installed on the outside of the output fiber 9. The output fiber 9 is fixed with a certain rigidity to prevent bending. The laser energy is directly applied to the processing area through the output fiber 9 to achieve laser removal of materials.

[0043] The electrolyte enters the liquid channel at the bottom of the processing head 5 from the side, and jets out into the processing area along the gap between the outer wall of the tubular electrode 10 and the inner wall of the annular front cathode 2. After processing, it carries the products and heat from the processing area and leaves the processing area along the side processing gap. The tubular electrode 10 and the front cathode 2 are respectively connected to the workpiece 1 to form a circuit, realizing the electrochemical removal of circumferential materials in the front processing area.

[0044] The outer side of the guide block 11 is a rotary sealing module 4. The rotary sealing module 4 controls the composite fiber electrode, which is coaxially fixed by the output fiber 9 and the tubular electrode 10, to rotate as the processing head 5 is fed, thereby enhancing the mass transfer effect in the processing area and improving the processing accuracy of deep small holes. The laser is transmitted through the fiber, avoiding the shielding effect of plasma generated by the high-energy laser breaking down the liquid, thus improving the laser energy utilization rate. At the same time, laser-assisted electrochemical processing has the promoting effects of increasing the current density in the processing area and enhancing mass transfer, which can realize the efficient processing of high-quality small holes with a large depth-to-diameter ratio.

[0045] In this embodiment of the invention, the electrochemical energy field is provided with a double closed loop. The high-frequency pulse power supply can realize jet electrolysis and laser composite processing through the front cathode 2 at the nozzle, the workpiece 1 and the electrolyte jet, and realize interventional tubular electrode electrolysis and laser composite processing through the tubular electrode 10, the workpiece 1 and the electrolyte jet. It can also simultaneously use dual electric field synchronous action and laser composite processing. The high power density laser directly acts on the front processing area to remove material, which improves processing efficiency and optimizes the electrolyte flow field distribution, thereby enhancing the localization of processing.

[0046] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A coaxial laser and jet electrolysis composite machining system, characterized in that, The system includes: a laser unit, an output optical fiber, a processing head, a liquid supply unit, and a first power supply; The laser unit is used to provide a laser beam to the output optical fiber; The processing head is provided with a laser channel, and the output optical fiber is disposed in the laser channel for transmitting the laser beam to the processing area of ​​the workpiece. A conductive structure is coaxially arranged on the outer side of the output optical fiber; The processing head is provided with a liquid channel, which is connected to the nozzle of the processing head. The liquid supply unit is used to provide electrolyte into the liquid channel so that the electrolyte is coaxially jetted from the gap between the nozzle sidewall and the conductive structure into the processing area of ​​the workpiece. The anode of the first power supply is connected to the workpiece, and the cathode of the first power supply is connected to the conductive structure. The system also includes a second power source; an annular hollow front cathode is installed on the sidewall of the nozzle. The anode of the second power supply is connected to the workpiece, and the cathode of the second power supply is connected to the front cathode; The electrolyte is coaxially jetted into the processing area of ​​the workpiece from the gap between the front cathode and the conductive structure.

2. The composite processing system according to claim 1, characterized in that, The conductive structure is a tubular electrode coaxially mounted on the output optical fiber or a metal coating covering the output optical fiber.

3. The composite processing system according to claim 1 or 2, characterized in that, The output optical fiber is a bare optical fiber.

4. The composite processing system according to claim 2, characterized in that, The conductive structure and the output optical fiber are coaxially fixed to form a composite optical fiber electrode. The processing head is also provided with a guide block; the guide block is used to fix and clamp the composite optical fiber electrode and guide it.

5. The composite processing system according to claim 4, characterized in that, A rotary sealing module is provided on the outside of the guide block. The rotary sealing module is sealed to the guide block and is used to drive the composite optical fiber electrode to rotate.

6. The composite processing system according to claim 1, characterized in that, The laser unit includes a laser, an input optical fiber, and a coupling module; The laser is used to emit a laser beam; The input optical fiber connects the laser and the coupling module, and is used to deliver the laser beam to the coupling module; The coupling module is used to couple the laser beam into the output optical fiber.

7. The composite processing system according to claim 6, characterized in that, The laser is a nanosecond pulse fiber laser or a nanosecond pulse solid-state laser; The laser beam emitted by the laser has a wavelength of 532nm or 1064nm.

8. The composite processing system according to claim 1 or 2, characterized in that, The output optical fiber is a quartz optical fiber or a glass optical fiber.

9. The composite processing system according to claim 8, characterized in that, The diameter of the output optical fiber is 0.1mm to 0.6mm.

Images