A laser-induced cavitation coupled electrode vibration electrolysis hole making device and method

Abstract

The application discloses a kind of laser-induced cavitation coupling electrode vibration electrolytic hole making device and method, equipment includes vibration platform, photoelectric liquid coupling cavity, tool electrode, exciter, laser generator, fixture, machine tool and pulse power, the Z axis of machine tool is connected with exciter by fixture, photoelectric liquid coupling cavity is connected on exciter, the lower end of photoelectric liquid coupling cavity and a tubular tool electrode are communicated, laser generator is opposite to tool electrode and is arranged through photoelectric liquid coupling cavity, workpiece is clamped on vibration platform, one pole of pulse power is electrically connected with workpiece, and the other pole is electrically connected with tool electrode, tool electrode and workpiece are coaxially arranged with the hole to be processed.The application realizes the efficient stability and high-quality processing of deep small hole by laser-induced cavitation, activated surface and vibration auxiliary improvement of electrolyte fluidity.

Description

Technical Field

[0001] This invention relates to the technical field of special processing, and in particular to a laser-induced cavitation coupling electrode vibration electrolytic hole-making device and method. Background Technology

[0002] With the development of science and technology, major engineering equipment such as aero-engines, domestically developed heavy-duty gas turbines, and air defense tactical weapons have placed extreme demands on the manufacturing of holes with ultra-large depth-to-diameter ratios. For example, radial cooling holes with a blade trailing edge diameter of 1mm can reach depths of over 200mm, and the machined surface must not have recast layers, microcracks, rust spots, or other defects due to the operating environment. These important components are often made of difficult-to-machine materials, and traditional machining is limited by the hardness and size of the cutting tools, making it difficult to machine deep small holes. Laser machining and electrical discharge machining are typical thermal processing methods, resulting in recast layers and microcracks on the hole walls after machining. Due to the limitations of the machining principles, the application of the above-mentioned machining methods in the machining of deep small holes in important equipment is restricted.

[0003] Electrolytic machining utilizes the principle of anodic dissolution in metal electrochemistry to remove materials. Tube electrode electrolytic machining is an important branch of electrolytic machining, employing a hollow metal tube as the tool electrode. During machining, the workpiece is connected to the positive terminal of the power supply, and the tube electrode to the negative terminal. When a certain voltage is applied between the workpiece and the tube electrode, the anodic material in the machining area begins to dissolve in ionic form. A high-speed flowing electrolyte is passed through the tube electrode to remove the electrolytic products and Joule heat generated during machining. Due to the advantages of electrolytic machining principles—no contact between the anode and cathode during machining, and the Joule heat being carried away by the electrolyte—the surface of the machined small holes is free of defects such as recast layers and microcracks, resulting in good surface integrity and high machining quality, making it particularly suitable for machining small holes with high aspect ratios. However, the generation of a large number of hydrogen bubbles at the bottom of the tool electrode reduces the stability of the electrolyte flow field and conductivity within the machining gap, thus affecting machining stability and quality. Furthermore, its relatively low machining efficiency limits its development and application.

[0004] To achieve efficient and stable machining of deep micro-holes, researchers have attempted to improve the performance of electrolytic hole-making processes using laser energy assistance. The University of Edinburgh in the UK studied coaxial electrolyte jet laser-assisted electrolytic machining technology, utilizing the principle of total internal reflection of the laser in a water jet to allow the laser and water jet to reach the material surface simultaneously, thus achieving simultaneous electrochemical and laser thermal removal. However, due to the inherent divergence of the jet, the jet morphology and electric field distribution of this method cannot be precisely controlled, making it difficult to apply to deep micro-hole machining. The Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, and KU Leuven in Belgium proposed a tubular electrode-constrained laser-electrochemical composite machining technology. This involves embedding a low-refractive-index non-metallic tube inside a metal tubular electrode, through which a high-speed flowing electrolyte is passed. Simultaneously, the laser undergoes total internal reflection on the inner wall of the tubular tool electrode and is transmitted to the machining area at the end of the tube electrode for material removal, thus achieving simultaneous composite machining of interventional laser electrolysis. However, this method exhibits significant laser thermal effects during processing, resulting in rough surfaces of the machined holes and microstructures, and even a small amount of recast layer residue. Xi'an Jiaotong University proposed a laser-electrolysis combined processing technology for micro-hole processing without recast layer. However, due to the limitations of laser processing technology, taper is inevitably generated during deep hole processing, which affects the shape and dimensional accuracy of the hole. Summary of the Invention

[0005] The purpose of this invention is to provide a laser-induced cavitation coupled electrode vibration electrolytic hole-making device and method to solve the problems existing in the prior art, so as to achieve high stability, high quality and high efficiency in the processing of deep small holes.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] This invention provides a laser-induced cavitation coupling electrode vibration electrolytic hole-making device, comprising a vibration platform, a photoelectric fluid coupling cavity, a tool electrode, an exciter, a laser generator, a fixture, a machine tool, and a pulse power supply. The Z-axis of the machine tool is connected to the exciter via the fixture. The photoelectric fluid coupling cavity is connected to the exciter, and its lower end is connected to a tubular tool electrode. The laser generator passes through the photoelectric fluid coupling cavity and is positioned opposite to the tool electrode. The laser generator is fixed to the machine tool. A workpiece is held on the vibration platform. One pole of the pulse power supply is electrically connected to the workpiece, and the other pole is electrically connected to the tool electrode. The tool electrode and the hole to be machined on the workpiece are arranged coaxially.

[0008] Preferably, the positive terminal of the pulse power supply is electrically connected to the workpiece, and the negative terminal is electrically connected to the tool electrode.

[0009] Preferably, the vibration platform is capable of unidirectional micro-amplitude vibration, and the vibration frequency and amplitude of both the vibration platform and the exciter can be set.

[0010] Preferably, the laser emitted by the laser generator is arranged coaxially with the tool electrode or the hole to be processed in the workpiece.

[0011] This invention also discloses an electrolytic hole-forming method, based on the above-mentioned laser-induced cavitation coupled electrode vibration electrolytic hole-forming device, comprising the following steps:

[0012] Step 1: Position and fix the workpiece on the vibration platform. Install the exciter, laser generator, photoelectric fluid coupling cavity, and tool electrode on the machine tool as required, and ensure that the laser focus of the laser generator is at the center of the tool electrode after connection. The tool electrode and the hole to be processed on the workpiece are arranged coaxially, so that the lower end of the tool electrode and the workpiece maintain an initial processing gap. Electrolyte is introduced into the photoelectric fluid coupling cavity. The positive terminal of the pulse power supply is connected to the workpiece, and the negative terminal is connected to the tool electrode.

[0013] Step 2: After the electrolyte flow stabilizes, turn on the vibration platform, the exciter, the laser generator and the pulse power supply, and simultaneously control the machine tool to drive the tool electrode to feed downwards along the Z-axis relative to the workpiece;

[0014] Step 3: When laser-induced cavitation generates microbubbles at the end of the tool electrode, the machine tool moves the tool electrode upward, and the vibration platform moves the workpiece downward. At this time, the processing gap is widened, the flow pressure within the processing gap decreases, and the bubbles accumulate and expand. The machine tool moves the tool electrode downward, and the vibration platform moves the workpiece upward. At this time, the bottom processing gap is compressed, the flow pressure within the gap increases, and the bubbles collapse under compression. The machine tool and the vibration platform continue to move towards each other, compressing the processing gap. The collapse of the bubbles generates shock waves and high temperatures, which simultaneously push the processed products out and assist in the erosion of the anode material.

[0015] Step four, until the deep holes on the workpiece are machined, the machine tool drives the tool electrode to retract, the workpiece is removed and cleaned.

[0016] Preferably, the vibration platform has a vibration frequency of 10Hz-50Hz and an amplitude of 0.01mm-0.1mm.

[0017] Preferably, the vibration frequency of the exciter is 10Hz-50Hz and the amplitude is 0.01mm-0.1mm.

[0018] Preferably, the initial processing gap in step one is not less than the sum of the amplitudes of the vibrator and the vibration platform.

[0019] The present invention achieves the following technical effects compared to the prior art:

[0020] 1. This invention utilizes laser-induced cavitation-vibration assisted deep micro-hole electrolytic machining. During machining, the tool electrode vibrates with the exciter, while the workpiece vibrates unidirectionally with the vibration platform. In this process, due to the effect of laser-induced cavitation, the hydrogen bubbles generated at the end of the tool electrode change from negative random occurrence and nonlinear distribution to controllable occurrence and uniform distribution, which enhances the controllability of the electrolyte flow field and conductivity, and ensures machining stability and quality.

[0021] 2. During the vibration process between the tool electrode and the workpiece, the present invention forms a pulsating pressure field in the processing gap, which accelerates the periodic cavitation growth and collapse of bubbles. When microbubbles collapse, high temperature and high pressure can be generated instantaneously, which promotes the renewal of electrolyte in the gap and achieves the effect of instantaneous removal of the anode material surface. The cavitation effect, combined with laser activation treatment of the workpiece surface and pulse electrolytic etching of workpiece material, can achieve efficient, stable and high-quality hole processing.

[0022] 3. The laser-induced cavitation-vibration of the present invention regulates the coupling between vibration and pulse by adjusting the energy of laser, electric field, vibration, and flow field. It is active and matches the vibration phase and frequency, which can achieve the best comprehensive process effect. As the processing depth changes, the laser energy and the speed of bubble generation can be adjusted in real time by controlling the laser power and the vibration frequency of the exciter. This counteracts the fluctuation of electrolyte bubble rate caused by pressure field changes, maintains the stability of processing current, and ensures stable processing.

[0023] 4. On the one hand, the present invention promotes the discharge of processed products by using the high-speed jet impact effect generated by laser-induced cavitation. On the other hand, the electrolyte rich in bubbles after cavitation has better fluidity, which is more conducive to the discharge of processed products. This method enhances the stability of electrolyte flow in the processing gap and significantly improves processing stability and efficiency. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of the laser-induced cavitation coupling electrode vibration electrolytic hole-making device of the present invention;

[0026] Figure 2 This is a partial structural schematic diagram of the laser-induced cavitation coupling electrode vibration electrolytic hole-making device of the present invention;

[0027] Figure 3 This is a schematic diagram of the process flow of the electrolytic hole-making method of the present invention;

[0028] Among them: 1-laser generator, 2-exciter, 3-pulse power supply, 4-Z-axis, 5-clamp, 6-photoelectric-hydraulic coupling cavity, 7-tool electrode, 8-workpiece, 9-vibration platform. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] The purpose of this invention is to provide a laser-induced cavitation coupled electrode vibration electrolytic hole-making device and method to solve the problems existing in the prior art and to achieve high stability, high quality and high efficiency in the processing of deep small holes.

[0031] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] Example 1

[0033] like Figures 1 to 2 As shown: This embodiment provides a laser-induced cavitation coupling electrode vibration electrolytic hole-making device, including a vibration platform 9, a photoelectric fluid coupling cavity 6, a tool electrode 7, an exciter 2, a laser generator 1, a fixture 5, a machine tool, and a pulse power supply 3. The Z-axis 4 of the machine tool is connected to the exciter 2 through the fixture 5. The photoelectric fluid coupling cavity 6 is connected to the exciter 2. The lower end of the photoelectric fluid coupling cavity 6 is connected to a tubular tool electrode 7. The laser generator 1 passes through the photoelectric fluid coupling cavity 6 and is arranged opposite to the tool electrode 7. The laser generator 1 is fixed on the machine tool. A workpiece 8 is clamped on the vibration platform 9. One (positive) pole of the pulse power supply 3 is electrically connected to the workpiece 8, and the other (negative) pole is electrically connected to the tool electrode 7. The tool electrode 7 and the hole to be processed on the workpiece 8 are arranged coaxially.

[0034] Specifically, the laser generator 1 is fixed on the machine tool and connected to the photoelectric-hydraulic coupling cavity 6 via an optical fiber. The positive terminal of the pulse power supply 3 is electrically connected to the workpiece 8, and the negative terminal is electrically connected to the tool electrode 7. The vibration platform 9 is capable of unidirectional micro-amplitude vibration. The vibration frequency and amplitude of the vibration platform 9 and the exciter 2 can be set. Specifically, the vibration platform 9 is a relatively mature electrolytic machining vibration device in this field, such as a single-axis electric slide or piezoelectric shaft. It can be controlled to perform reciprocating motion with a set frequency and amplitude. Therefore, any mechanism with single-axis linear reciprocating motion function is acceptable. The laser emitted by the laser generator 1 is coaxial with the tool electrode 7 or the hole to be processed on the workpiece 8 to ensure drilling accuracy.

[0035] Example 2

[0036] like Figure 3 As shown: This embodiment discloses an electrolytic hole-forming method, based on the laser-induced cavitation coupled electrode vibration electrolytic hole-forming device of Embodiment 1, including the following steps:

[0037] Step 1: Position and fix the workpiece 8 on the vibration platform 9. The exciter 2, laser generator 1, photoelectric-hydraulic coupling cavity 6 and tool electrode 7 are all installed on the machine tool as required, and ensure that the laser focus of the laser generator 1 after connection is at the center of the tool electrode 7. The tool electrode 7 and the hole to be processed on the workpiece 8 are set coaxially, so that the lower end of the tool electrode 7 and the workpiece 8 maintain an initial processing gap. Electrolyte is introduced into the photoelectric-hydraulic coupling cavity 6. The positive terminal of the pulse power supply 3 is connected to the workpiece 8 and the negative terminal is connected to the tool electrode 7.

[0038] Step 2: After the electrolyte flow stabilizes, turn on the vibration platform 9, exciter 2, laser generator 1 and pulse power supply 3, and simultaneously control the machine tool to drive the tool electrode 7 to feed downwards relative to the workpiece 8 along the Z-axis 4.

[0039] Step three: When laser-induced cavitation generates microbubbles at the end of the tool electrode 7, the machine tool moves the tool electrode 7 upward, and the vibration platform 9 moves the workpiece 8 downward. At this time, the processing gap is widened, the flow pressure within the processing gap decreases, and the bubbles accumulate and expand. Within one vibration cycle, the machine tool moves the tool electrode 7 downward, and the vibration platform 9 moves the workpiece 8 upward. At this time, the bottom processing gap is compressed, the flow pressure within the gap increases, and the bubbles collapse under compression. The machine tool and vibration platform 9 continue to move towards each other, compressing the processing gap. The bubble collapse generates shock waves and high temperatures, which simultaneously push the processed products out and assist in the erosion of the anode material. As the processing depth changes, the laser energy and the rate of bubble generation can be adjusted in real time by controlling the laser power and the vertical vibration frequency. This counteracts the fluctuations in the electrolyte bubble rate caused by changes in the pressure field, maintains the stability of the processing current, and ensures stable processing.

[0040] Step four, until the deep holes on workpiece 8 are machined, the machine tool drives the tool electrode 7 to retract, and workpiece 8 is removed and cleaned.

[0041] Specifically, the vibration frequency of the vibration platform 9 is 10Hz-50Hz, and the amplitude is 0.01mm-0.1mm. The vibration frequency of the exciter 2 is 10Hz-50Hz, and the amplitude is 0.01mm-0.1mm. The initial machining gap in step one is not less than the sum of the amplitudes of the exciter 2 and the vibration platform 9 to avoid motion interference during the initial machining.

[0042] The electrolytic hole-making method in this embodiment is of great significance for improving the machining accuracy, machining stability and machining efficiency of deep small hole structures.

[0043] This specification uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A laser-induced cavitation coupled electrode vibration electrolytic hole-forming device, characterized in that: The system includes a vibration platform, a photoelectric-hydraulic coupling cavity, a tool electrode, an exciter, a laser generator, a fixture, a machine tool, and a pulse power supply. The Z-axis of the machine tool is connected to the exciter via the fixture. The photoelectric-hydraulic coupling cavity is connected to the exciter, and its lower end is connected to a tubular tool electrode. The laser generator passes through the photoelectric-hydraulic coupling cavity and is positioned opposite to the tool electrode. The laser generator is fixed to the machine tool. A workpiece is held on the vibration platform. One pole of the pulse power supply is electrically connected to the workpiece, and the other pole is electrically connected to the tool electrode. The tool electrode and the hole to be machined on the workpiece are arranged coaxially. The vibration platform is capable of unidirectional micro-amplitude vibration, and the vibration frequency and amplitude of the vibration platform and the exciter can be set.

2. The laser-induced cavitation coupling electrode vibration electrolytic hole-making device according to claim 1, characterized in that: The positive terminal of the pulse power supply is electrically connected to the workpiece, and the negative terminal is electrically connected to the tool electrode.

3. The laser-induced cavitation coupling electrode vibration electrolytic hole-making device according to claim 1, characterized in that: The laser emitted by the laser generator is arranged coaxially with the tool electrode or the hole to be processed in the workpiece.

4. An electrolytic hole-forming method, based on the laser-induced cavitation coupled electrode vibration electrolytic hole-forming device according to any one of claims 1-3, characterized in that: Includes the following steps: Step 1: Position and fix the workpiece on the vibration platform. Install the exciter, laser generator, photoelectric fluid coupling cavity, and tool electrode on the machine tool as required, and ensure that the laser focus of the laser generator is at the center of the tool electrode after connection. The tool electrode and the hole to be processed on the workpiece are arranged coaxially, so that the lower end of the tool electrode and the workpiece maintain an initial processing gap. Electrolyte is introduced into the photoelectric fluid coupling cavity. The positive terminal of the pulse power supply is connected to the workpiece, and the negative terminal is connected to the tool electrode. Step 2: After the electrolyte flow stabilizes, turn on the vibration platform, the exciter, the laser generator and the pulse power supply, and simultaneously control the machine tool to drive the tool electrode to feed downwards along the Z-axis relative to the workpiece. Step 3: When laser-induced cavitation generates microbubbles at the end of the tool electrode, the machine tool moves the tool electrode upward, and the vibration platform moves the workpiece downward. At this time, the processing gap is widened, the flow pressure within the processing gap decreases, and the bubbles accumulate and expand. The machine tool moves the tool electrode downward, and the vibration platform moves the workpiece upward. At this time, the bottom processing gap is compressed, the flow pressure within the gap increases, and the bubbles collapse under compression. The machine tool and the vibration platform continue to move towards each other, compressing the processing gap. The collapse of the bubbles generates shock waves and high temperatures, which simultaneously push the processed products out and assist in the erosion of the anode material. Step four, until the deep holes on the workpiece are machined, the machine tool drives the tool electrode to retract, the workpiece is removed and cleaned.

5. The electrolytic hole-forming method according to claim 4, characterized in that: The vibration platform has a vibration frequency of 10Hz-50Hz and an amplitude of 0.01mm-0.1mm.

6. The electrolytic hole-forming method according to claim 4, characterized in that: The vibration frequency of the exciter is 10Hz-50Hz and the amplitude is 0.01mm-0.1mm.

7. The electrolytic hole-forming method according to claim 4, characterized in that: The initial processing gap in step one is not less than the sum of the amplitudes of the exciter and the vibration platform.

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