Laser interference and electrolysis collaborative processing system and high aspect ratio micro-nano hole processing method

Abstract

The present invention discloses a laser interference and electrolysis collaborative processing system and a high aspect ratio micro-nano hole processing method, comprising a laser, an interference optical path system and an electrochemical processing system; the laser is used to generate and output a laser beam of specific power and frequency; the interference optical path system comprises a beam splitter, a half-wave plate, a polarizer, and a high-reflection mirror, the laser beam generated by the laser is split into at least two beams by the beam splitter, each laser beam is transmitted to the processed workpiece through the polarizer, half-wave plate and high-reflection mirror, forming a specific interference light field; the electrochemical processing system comprises a pulse power supply, an electrolyte and an electrolytic cell, the processed workpiece serves as an anode connected to the positive electrode of the pulse power supply, and transparent conductive glass serves as a cathode connected to the negative electrode of the pulse power supply, the processed workpiece and the transparent conductive glass are both located in the electrolyte of the electrolytic cell, and the gap between the transparent conductive glass and the processed workpiece ranges from 0.01 to 5 mm; the present invention provides new ideas and solutions for the manufacture of new structural and functional integrated materials.

Description

Technical Field

[0001] The invention belongs to the field of micro-nano processing technology, and in particular relates to a method for smoothing the outer plate of an asymmetric tail shaft. Background Art

[0002] High aspect ratio nanopores have broad application prospects in improving material properties and developing bionic applications. For example, by preparing an array of high aspect ratio nanopores on the surface of a material, the material can have better wave absorption performance, hydrophobicity, adhesion or material compatibility. By preparing high aspect ratio nanopores on the surface of the light absorption layer of a solar cell, the effective working area can be expanded and the light absorption rate can be improved. By studying the mechanical behavior of materials under high aspect ratio apertures, new high-performance materials can be prepared.

[0003] Laser processing is a recognized technology for fabricating micro-nanostructures, but it is limited by the Rayleigh length of traditional Gaussian beams, making it difficult to fabricate nanopore structures with high aspect ratios. Although spatiotemporal shaping of laser beams using Bessel beams can achieve this feat, the beam shaping system is complex and places extremely high demands on light field quality and damage resistance of the shaping elements, making it difficult to meet the requirements for large-scale, efficient, and economical manufacturing.

[0004] Laser interference processing is one of the recognized large-area micro-nanostructure manufacturing technologies. It uses the superposition of multiple coherent light beams to generate a periodically modulated laser light intensity energy distribution. When interacting with the substrate material, it can prepare a large-area micro-nano array aperture structure on the material surface. However, this technology is limited by its own interference contrast and cannot achieve high aspect ratio nanohole processing.

[0005] Electrolytic machining removes material on the surface of the material in the form of ion migration through electrolytic reactions. In principle, it has nanoscale manufacturing capabilities. However, due to its poor localization, the obtained nanopore structure has poor consistency, which limits the nanomanufacturing capabilities of this technology. Summary of the Invention

[0006] In view of the above problems, the purpose of the present invention is to propose a method that organically combines laser interference processing technology and electrolytic processing technology to achieve collaborative processing of micro-nano structures on the surface of materials under the action of a coupled energy field, especially for processing nanopores with high aspect ratios.

[0007] The present invention adopts the following technical solutions to achieve the present invention:

[0008] Laser interference and electrochemical collaborative processing system, including laser, interference optical path system and electrochemical processing system;

[0009] The laser is used to generate and output a laser beam of specific power and frequency;

[0010] The interference optical path system includes a beam splitter, a half-wave plate, a polarizer, and a high-reflection mirror. The laser beam generated by the laser is split into at least two beams by the beam splitter. Each laser beam is transmitted to the workpiece through the polarizer, half-wave plate, and high-reflection mirror to form a specific interference light field.

[0011] The electrochemical machining system includes a pulse power supply, an electrolyte and an electrolytic cell. The workpiece to be processed is connected to the positive electrode of the pulse power supply as an anode, and the transparent conductive glass is connected to the negative electrode of the pulse power supply as a cathode. The workpiece to be processed and the transparent conductive glass are both located in the electrolyte of the electrolytic cell, and the gap between the transparent conductive glass and the workpiece to be processed ranges from 0.01 to 5 mm.

[0012] Furthermore, the system also includes a control system and a monitoring system, wherein the monitoring system monitors the electrolysis current, the gap between the two electrodes, the electrolyte circulation status and the laser interference pattern morphology; the control system adjusts the current, the gap between the two electrodes, the electrolyte circulation inlet and outlet pressures and the relative positions of the optical elements in the interference light path system based on the feedback from the monitoring system.

[0013] Furthermore, each laser beam is incident vertically when it is emitted from the air medium into the electrolyte, and each laser beam has the same transmission distance in the electrolyte, ensuring the formation of a stable interference light field in the processing area.

[0014] Furthermore, each laser beam propagates to the workpiece through the polarizer, half-wave plate and high-reflection mirror to form a specific interference pattern. If the laser does not pass through the transparent conductive glass, the laser will propagate between the transparent conductive glass and the workpiece to the workpiece.

[0015] Furthermore, each laser beam propagates through the polarizer, half-wave plate and high-reflection mirror to the workpiece to form a specific interference pattern. If the laser passes through the transparent conductive glass to the workpiece to be processed, the laser beam passes through the transparent conductive glass vertically.

[0016] Furthermore, the laser is one or a combination of nanosecond green laser, femtosecond green laser, nanosecond infrared laser, picosecond infrared laser, and femtosecond infrared laser, and the laser output power is adjustable in the range of 0.01 to 10W.

[0017] Furthermore, the electrolyte is a sodium nitrate solution or a sodium chloride solution.

[0018] The method for processing micro-nanoholes with high aspect ratio using the laser interference and electrolysis collaborative processing system includes the following steps:

[0019] The laser beam generated by the laser is divided into at least two beams. Each laser beam propagates to the workpiece to be processed, forming a specific interference light field. The interference light field formed by each laser beam on the surface of the workpiece to be processed coincides with the processing area of ​​the electrochemical processing system. Under the interaction of the coupled energy field, the laser interference pattern is used to locally induce an electrolytic reaction to remove material, thereby realizing the coordinated processing of micro-nano composite structures on the plane and high aspect ratio aperture structures in the vertical direction.

[0020] Furthermore, the material of the workpiece being processed is α+β titanium alloy or nickel-based single crystal high-temperature alloy.

[0021] Furthermore, the material of the workpiece being processed has an electrical conductivity greater than 1×10 6 S / m conductor.

[0022] The beneficial technical effects of the present invention are:

[0023] 1. The processing method of the present invention not only overcomes the technical bottleneck of laser interferometry, which is limited by light intensity contrast and cannot process deep holes, but also solves the inherent defect of traditional electrolytic reaction, which cannot achieve spatial selective etching of materials. It provides a new idea and solution for the manufacture of new structural and functional integrated materials.

[0024] 2. The present invention proposes a method that organically combines laser interference processing technology and electrolytic processing technology. Under the action of a coupled energy field, the influence of light intensity distribution on the electrochemical reaction current is utilized to achieve laser interference pattern-induced electrolytic processing to selectively remove materials. The present invention is used for the coordinated processing of micro-nano structures on the surface of materials, and can especially be used for processing nano-apertures with high aspect ratios. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of a laser interferometry and electrolysis collaborative processing system provided in Example 2 of the present invention;

[0026] Figure 2 Schematic diagram of a laser interference and electrolysis collaborative processing system provided in Example 3 of the present invention;

[0027] Figure 3 Schematic diagram of the control structure of the laser interference and electrolysis collaborative processing system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0028] Example 1

[0029] The present invention discloses a laser interference and electrolysis collaborative processing system, comprising a laser, an interference optical path system and an electrochemical processing system;

[0030] The laser is used to generate and output a laser beam of specific power and frequency;

[0031] The interference optical path system includes a beam splitter, a half-wave plate, a polarizer, and a high-reflection mirror. The laser beam generated by the laser is split into at least two beams by the beam splitter. Each laser beam is transmitted to the workpiece through the polarizer, half-wave plate, and high-reflection mirror to form a specific interference light field.

[0032] The electrochemical machining system includes a pulse power supply, an electrolyte and an electrolytic cell. The workpiece to be processed serves as an anode connected to the positive electrode of the pulse power supply, and the transparent conductive glass (ITO) serves as a cathode connected to the negative electrode of the pulse power supply. The workpiece to be processed and the transparent conductive glass are both located in the electrolyte of the electrolytic cell, and the gap between the transparent conductive glass and the workpiece to be processed ranges from 0.01 to 5 mm.

[0033] The system also includes a control system and a monitoring system. The monitoring system monitors the electrolytic machining current, the gap between the two electrodes, the electrolyte circulation status and the laser interference pattern; the control system adjusts the current, the electrode gap, the electrolyte circulation inlet and outlet pressures and the relative positions of the optical elements in the interference light path system based on the feedback from the monitoring system.

[0034] It should be noted that when each laser beam is transmitted to the workpiece to be processed through a polarizer, a half-wave plate and / or a high-reflection mirror to form a specific interference pattern, if the laser does not pass through the transparent conductive glass, the laser will be transmitted from the transparent conductive glass to the workpiece to be processed. This is because when the laser passes through the transparent conductive glass non-vertically, refraction will cause laser energy loss and focus drift, affecting the processing accuracy and efficiency. Therefore, it can also be considered that when each laser beam is transmitted to the workpiece to be processed through a polarizer, a half-wave plate and / or a high-reflection mirror to form a specific interference pattern, if the laser passes through the transparent conductive glass to the workpiece to be processed, the laser beam passes vertically through the transparent conductive glass. In order to avoid changing the beam propagation path due to refraction, each laser beam is vertically incident when it is emitted from the air medium into the electrolyte. Each beam has the same transmission distance in the electrolyte, which can ensure that a stable interference light field is formed in the material surface processing area.

[0035] The interference optical path system includes a beam splitter, a half-wave plate, a polarizer, and a high-reflection mirror. The interference optical path system is used to control parameters such as laser energy, polarization state, spatial angle, and incident angle, thereby splitting the laser beam and causing it to propagate along different paths, ultimately superimposing a preset interference pattern in the processing area. The electrochemical processing system utilizes the principle of electrochemical reaction of metal in electrolyte to achieve controllable removal of materials.

[0036] In addition, the laser is one or a combination of nanosecond green laser, femtosecond green laser, nanosecond infrared laser, picosecond infrared laser, and femtosecond infrared laser, and the laser output power is adjustable in the range of 0.01-10W; to ensure the processing accuracy and surface quality of the workpiece being processed, the electrolytic machining system adopts a pulse power supply; the electrolyte is sodium nitrate (NaNO3) solution or sodium chloride (NaCl) solution.

[0037] The method for processing high aspect ratio micro-nanoholes using the above-mentioned laser interference and electrolytic collaborative processing system includes the following steps:

[0038] The laser beam generated by the laser is divided into at least two beams. Each laser beam propagates to the workpiece to be processed, forming a specific interference light field. The interference light field formed by each laser beam on the surface of the workpiece to be processed coincides with the processing area of ​​the electrochemical processing system. Under the interaction of the coupled energy field, the laser interference pattern is used to induce the electrolytic reaction to remove the material locally, thereby realizing the coordinated processing of the micro-nano composite structure in the plane and the high aspect ratio nanopore structure in the vertical direction. It should be noted that the distance between adjacent nanopores is at the micron level, which can be said to be a micro-nano composite structure academically; the presence of both nanopores and micropores on the plane is also a micro-nano composite structure. The technology of this application can achieve structural processing in both cases.

[0039] It should be noted that the material of the workpiece processed according to the method of this application can be α+β type titanium alloy such as TC4, TC6, nickel-based single crystal high temperature alloy such as DD6, DD402, etc., and at least the material of the workpiece being processed has an electrical conductivity greater than 1×10 6 S / m conductor.

[0040] The present application realizes spatial coupling by integrating the laser interference optical path system and the electrochemical machining system. It is possible to consider placing a reflector close to the inner wall of the electrolytic cell so that the interference light field formed on the material surface after each light beam is reflected by the liquid phase coincides with the processing area of ​​the electrochemical machining system. The multi-beam laser interference field is used to form a periodically modulated light intensity energy distribution to spatially locate the electrochemical machining anodic oxidation reaction, and realize the selective removal of materials and the coordinated processing of surface micro-nanotopological structures under the interaction of multiple fields. Specifically, two or more coherent laser beams are superimposed on the workpiece surface to form a high-energy-density periodic interference pattern, in which the interference pattern area causes a localized high-temperature effect due to the sudden increase in light intensity, resulting in material phase change, oxide layer rupture and lattice defect generation, thereby enhancing the anodic dissolution activity of the area. At the same time, the micro-region temperature gradient induced by the interference thermal field changes the electrolyte ion migration rate and the diffusion boundary layer thickness, realizing the synergistic effect of strengthening the ion exchange kinetics in the active area and inhibiting etching in the non-processing area, ultimately achieving nano-scale selective etching and efficient and controllable forming of complex microstructures.

[0041] Example 2

[0042] Based on Example 1, the laser interference and electrolysis collaborative processing system provided in this embodiment is as follows: Figure 1 As shown, the system includes a laser, an interference optical path system and an electrochemical processing system. The thick solid line in the figure represents the propagation path of the laser beam;

[0043] The laser is used to generate and output a laser beam with specific power and frequency; the laser light source includes but is not limited to nanosecond green light, femtosecond green light, nanosecond infrared, picosecond infrared, femtosecond infrared, etc.; the laser power can be adjusted in the range of 0.01 to 10W.

[0044] The interference optical path system includes a high-reflection mirror 10, a polarizer 20, a half-wave plate 30 and a beam splitter 40; wherein the high-reflection mirror is used to change the propagation direction of the laser to achieve the turning and adjustment of the optical path; the polarizer is used to adjust the polarization direction of the laser; the half-wave plate is used to adjust the polarization state of the laser to achieve polarization interference; the beam splitter is used to split a laser beam into two beams according to a certain ratio.

[0045] like Figure 1 As shown, the laser propagation path is that the laser beam output by the laser is reflected twice by the high-reflection mirror 10 and is split into two proportional light beams by the beam splitter 40. The separated light beams pass through the polarizer 20 and the half-wave plate 30 in sequence and enter the electrolytic cell 70 of the electrochemical machining system. They are reflected by the high-reflection mirror 10 on the inner wall of the cell to the workpiece 60. The two separated light beams form a specific interference pattern on the workpiece 60. In order to avoid unnecessary refraction of light passing through the transparent conductive glass (ITO), the high-reflection mirror 10 on the inner wall of the electrolytic cell 70 is adjusted so that the light is reflected by it and then propagates from under the transparent conductive glass to the workpiece.

[0046] The electrochemical machining system includes a pulse power supply, an electrolyte and an electrolytic cell; wherein the workpiece to be processed is made of metal, the workpiece to be processed serves as an anode connected to the positive electrode of the pulse power supply, the transparent conductive glass 50 serves as a cathode connected to the negative electrode of the power supply, and the gap M between the transparent conductive glass (ITO) and the metal workpiece to be processed ranges from 0.01 to 5 mm; the electrolyte 80 in the electrolytic cell includes but is not limited to sodium nitrate (NaNO3) or sodium chloride (NaCl) solution, and the solution concentration ranges from 10% to 30%.

[0047] The monitoring system monitors the machining current, electrode gap, electrolyte circulation status and laser interference pattern on the motion platform in the electrochemical machining system, and collects the monitored information through a multi-channel data acquisition card and feeds it back to the control system. Here, the monitoring system can collect the machining current signal based on the Hall current sensor in the circuit; monitor the electrode gap based on the laser displacement sensor and the gap estimation algorithm; measure the electrolyte circulation pressure based on the pressure sensor in the electrolyte circulation pipeline; monitor the laser interference pattern morphology based on a high-speed camera combined with a microscope objective lens; the control system realizes the regulation of the machining current by adjusting the voltage between the two electrodes in the electrochemical machining system; adjusts the electrolyte circulation pressure status based on the electrolyte circulation pump; adjusts the gap between the two electrodes based on the micro servo motor at the motion platform; adjusts the interference pattern on the workpiece being processed at the motion platform based on the relative positions of the beam splitter, half-wave plate, polarizer and high-reflection mirror in the optical path system, thereby realizing precise control of the machining parameters.

[0048] In this embodiment, the above-mentioned method is used to perform electrolytic coupling processing on the metal workpiece under the induction of the laser interference field, and the obtained micro-nano composite structure composed of nanometer-scale apertures (0.1 to 200 nanometers) and micrometer-scale aperture gaps (800 to 1200 nanometers) in the plane and the nanopore structure with a high aspect ratio (1:50) in the vertical direction are overcome. The technical difficulties of poor localization of traditional single electrolytic processing and the inability of single laser processing to achieve high aspect ratio aperture processing are overcome, and an innovative processing method and supporting system are provided for the field of micro-nano processing.

[0049] Example 3

[0050] Based on Example 1, the laser interference and electrolysis collaborative processing system provided in this embodiment is as follows: Figure 2 As shown in FIG, the system includes a laser, an interference optical path system, and an electrochemical processing system. The thick solid line in the figure represents the propagation path of the laser beam.

[0051] The laser is used to generate and output laser light of specific power and specific frequency; the laser light source includes but is not limited to nanosecond green light, femtosecond green light, nanosecond infrared, picosecond infrared, femtosecond infrared, etc.; the laser power range is 0.01 to 10W.

[0052] The interference optical path system includes a high-reflection mirror 10, a polarizer 20, a half-wave plate 30, and a beam splitter 40. The laser propagation path is as follows: laser light output from a laser is reflected twice by the high-reflection mirror 10. The first beam splitter splits the beam into two laser beams with a power ratio of 1:2. The separated high-power beam passes through the second beam splitter, which also splits the beam into two laser beams in equal proportions. The two laser beams and the low-power beam separated by the first beam splitter respectively pass through the polarizer 20 and the half-wave plate 30 and enter the electrolytic cell 70 of the electrochemical machining system. They are then reflected by the high-reflection mirror 10 on the inner wall of the cell onto the workpiece 60 being machined. The three separated equal-energy beams form a specific interference pattern on the workpiece being machined. To avoid unnecessary refraction of light passing through the transparent conductive glass (ITO), the high-reflection mirror 10 on the inner wall of the electrolytic cell 70 is adjusted so that the light on the left and right sides is reflected by it and then propagates from under the transparent conductive glass to the workpiece being machined.

[0053] It should be noted that the beam splitter in this embodiment is not limited to splitting the laser into two beams, but can also split the laser into multiple beams, which can be achieved by providing a combination of multiple sets of beam splitters and reflective mirrors.

[0054] The electrochemical machining system includes a pulse power supply, an electrolyte, and an electrolytic cell. The workpiece 60 is made of metal, the workpiece serves as an anode connected to the positive electrode of the pulse power supply, and a transparent conductive glass (ITO) serves as a cathode connected to the negative electrode of the power supply. The gap M between the transparent conductive glass 50 and the workpiece 60 ranges from 0.01 to 5 mm. The electrolyte 80 in the electrolytic cell includes, but is not limited to, sodium nitrate (NaNO3) or sodium chloride (NaCl) solution, with a concentration ranging from 10% to 30%.

[0055] Alternatively, a motion platform can be installed in the electrolytic cell to support and position the workpiece to be processed. A monitoring system monitors the machining current, electrode gap, electrolyte circulation status, and the morphology of the laser interference fringes on the motion platform in the electrochemical machining system, and collects and feeds this information back to the control system via a multi-channel data acquisition card. The monitoring system can collect machining current signals using a Hall effect current sensor in the circuit; monitor the electrode gap using a laser displacement sensor and a gap estimation algorithm; measure the electrolyte circulation pressure using a pressure sensor in the electrolyte circulation pipeline; and monitor the morphology of the laser interference fringes using a high-speed camera combined with a microscope objective. The control system regulates the machining current by adjusting the voltage between the two electrodes in the electrochemical machining system; adjusts the electrolyte circulation pressure using an electrolyte circulation pump; adjusts the gap between the two electrodes using a microservo motor on the motion platform; and adjusts the interference fringes on the workpiece being machined on the motion platform based on the relative positions of the beam splitter, half-wave plate, polarizer, and high-reflection mirror in the optical path system, thereby achieving precise control of machining parameters.

[0056] In this embodiment, the above-mentioned method is used to perform laser interference and electrolytic coupling processing on the metal workpiece to obtain an in-plane micro-nano composite structure and a nanopore structure with a high aspect ratio (1:50) in the vertical direction. This overcomes the technical difficulties of poor localization of traditional single electrolytic processing and the inability of single laser processing to achieve high aspect ratio aperture processing, and provides an innovative processing method and supporting system for the field of micro-nano processing.

[0057] The control system is used to coordinate and control the laser parameters, interference fringe distribution and electrochemical processing parameters; the monitoring system is used to monitor and feedback the interference fringe state and electrochemical reaction state in the processing process in real time to ensure the processing quality.

[0058] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

Claims

1. Laser interference and electrolysis collaborative processing device, characterized in that: Including laser, interference optical system and electrochemical processing system; The laser is used to generate and output a laser beam of specific power and frequency; The interference optical path system includes a beam splitter, a half-wave plate, a polarizer, and a high-reflection mirror. The laser beam generated by the laser is split into at least two beams by the beam splitter. Each laser beam is transmitted to the workpiece through the polarizer, half-wave plate, and high-reflection mirror to form a specific interference light field. The electrochemical machining system includes a pulse power supply, an electrolyte, and an electrolytic cell. The workpiece being machined serves as an anode connected to the positive electrode of the pulse power supply, and the transparent conductive glass serves as a cathode connected to the negative electrode of the pulse power supply. The workpiece being machined and the transparent conductive glass are both located in the electrolyte of the electrolytic cell, and the gap between the transparent conductive glass and the workpiece being machined ranges from 0.01 to 5 mm. Each laser beam is incident vertically when it enters the electrolyte from the air medium. Each laser beam has the same transmission distance in the electrolyte, ensuring the formation of a stable interference light field in the processing area. Each laser beam propagates through a polarizer, a half-wave plate, and a high-reflection mirror to the workpiece being processed, forming a specific interference pattern. If the laser does not pass through the transparent conductive glass, the laser will propagate between the transparent conductive glass and the workpiece being processed to the workpiece being processed; if the laser passes through the transparent conductive glass to the workpiece being processed, the laser beam will pass through the transparent conductive glass vertically.

2. The laser interference and electrolytic collaborative processing device according to claim 1, characterized in that: The system also includes a control system and a monitoring system. The monitoring system monitors the electrolysis current, the gap between the two electrodes, the electrolyte circulation status and the laser interference pattern morphology; the control system adjusts the current, the gap between the two electrodes, the electrolyte circulation inlet and outlet pressures and the relative positions of the optical elements in the interference light path system based on the feedback from the monitoring system.

3. The laser interference and electrolytic collaborative processing device according to claim 1, characterized in that: The laser is one or a combination of nanosecond green laser, femtosecond green laser, nanosecond infrared laser, picosecond infrared laser, and femtosecond infrared laser, and the laser output power is adjustable in the range of 0.01 to 10W.

4. The laser interference and electrolytic collaborative processing device according to claim 1, characterized in that: The electrolyte is sodium nitrate solution or sodium chloride solution.

5. A method for processing micro-nanoholes with high aspect ratio using the laser interference and electrolytic collaborative processing device according to any one of claims 1 to 4, characterized in that: The steps include: The laser beam generated by the laser is divided into at least two beams. Each laser beam propagates to the workpiece to be processed, forming a specific interference light field. The interference light field formed by each laser beam on the surface of the workpiece to be processed coincides with the processing area of ​​the electrochemical processing system. Under the interaction of the coupled energy field, the laser interference pattern is used to locally induce an electrolytic reaction to remove material, thereby realizing the coordinated processing of micro-nano composite structures on the plane and high aspect ratio aperture structures in the vertical direction.

6. The method for processing micro-nanoholes with high aspect ratio according to claim 5, characterized in that: The material of the processed part of the workpiece is α+β type titanium alloy or nickel-based single crystal high temperature alloy.

7. The method for processing micro-nanoholes with a high aspect ratio according to claim 5, wherein: The material of the workpiece being processed has an electrical conductivity of > 1×10 6 S / m conductor.

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