Laser-enhanced area electroforming additive manufacturing device and method

Abstract

The invention provides a laser-enhanced area electroforming additive manufacturing device and method. The device comprises an electroforming power supply, a master control system, a circulating system, a laser system, an electroforming tank, an area array micro-jet printing head erected in the electroforming tank, a cathode substrate arranged below the area array micro-jet printing head and a cathode driving system, the cathode substrate is not in contact with the inner wall and the bottom of the electroforming tank; the laser system comprises a beam shaping module; a linear strip-shaped laser beam emitted by the beam shaping module passes through the electrolyte in the liquid storage shell and the micro nozzle through the light transmitting window and then is vertically irradiated on the cathode substrate; and the line-strip-shaped laser beam covers all the micro nozzles. The method is a laser-enhanced area electroforming additive manufacturing method using the device. According to the device and the method, the deposition rate and the production efficiency can be greatly improved, the printing resolution ratio and the forming precision are improved, the structural part with higher performance can be obtained, and the performance of the structural part is easier to regulate and control.

Description

Technical Field

[0001] This application relates to the field of additive manufacturing technology, and in particular to a laser-enhanced area electroforming additive manufacturing apparatus and method. Background Technology

[0002] Additive manufacturing is a manufacturing technology that constructs three-dimensional solids through "layer printing and layer stacking". Its principle is to use various energy sources such as lasers, electron beams, UV light, hot nozzles, adhesives, and ultrasound to instantly melt, solidify, or bond "point-line" or "line" materials to form a continuous stack of "point-line-surface-volume", reducing "three-dimensional processing" to "two-dimensional printing + one-dimensional stacking", and achieving near-net-shape manufacturing with "what you see is what you get".

[0003] Additive manufacturing can be categorized into photopolymerization, binder jetting, and powder bed fusion. Among these, powder bed fusion is currently the most widely used additive manufacturing method for metal materials due to its high printing efficiency and precision. Powder bed fusion additive manufacturing includes selective laser melting (SLM), electron beam melting (EBM), and selective laser sintering (SLS). In selective laser melting (SLM), metal powder (such as titanium alloys, aluminum alloys, stainless steel, and high-temperature alloys) is spread evenly on a powder bed (layer thickness 0.02~0.1mm); a high-power laser (such as a fiber laser) scans along a cross-sectional path, completely melting and solidifying the metal powder in the scanned area (forming a dense solid); after one layer is completed, the powder bed descends, new powder is placed on top, and the process is repeated; unmelted powder is removed after forming. Electron beam melting (EBM) is similar to selective laser sintering (SLM), but the heat source is a high-energy electron beam (rather than a laser). In a high vacuum environment, the electron beam bombards metal powder (such as titanium alloys and cobalt-chromium alloys), converting kinetic energy into heat energy to melt the powder. The vacuum environment prevents metal oxidation, and the electron beam has higher energy (suitable for metals with high melting points). Selective laser sintering (SLS) is similar to SLM, but the heat source laser power is lower, only "sintering" the powder (particles are bonded together, not completely melted); after one layer is sintered, the powder bed descends, new powder is deposited, and the process is repeated.

[0004] Although powder bed fusion additive manufacturing of metal materials is widely used due to its high printing efficiency and accuracy, the extreme high temperature in the processing area becomes a "no-go zone" for heat-sensitive components. Electroforming, on the other hand, is an additive manufacturing method that relies on electrochemical deposition and can be applied layer by layer at room temperature, which provides a potential advantageous solution for these temperature-sensitive parts.

[0005] Electroforming is an additive manufacturing technology that utilizes the principle of electrochemical deposition. Electroforming additive manufacturing is an advanced material forming technology that integrates traditional electroforming technology with the core concept of "layered manufacturing" in additive manufacturing. Essentially, it uses electrochemical deposition to precisely deposit metal ions layer by layer onto a pre-set substrate, ultimately constructing metal components with complex three-dimensional structures, thus achieving direct manufacturing from digital models to physical parts.

[0006] Currently, numerous technical solutions for applying electroforming to additive manufacturing exist both domestically and internationally, primarily including mask electrodeposition, confined electrodeposition, laser-enhanced electrodeposition, jet electrodeposition, and area lattice electrodeposition. Mask electrodeposition is the most commonly used, boasting high technological maturity, widespread industrial application, good process stability, and significant mass production potential. However, mask preparation is costly and time-consuming, presenting challenges for forming high aspect ratio structures. Furthermore, to ensure deposition quality, mask electrodeposition requires the use of high-purity metal salt electrolytes (such as nickel sulfate or copper sulfate solutions), necessitating strict control of impurity content in the electrolyte, thus placing certain pressures on electrolyte management and environmental protection.

[0007] Laser-enhanced electrodeposition has a faster deposition rate than mask electrodeposition, making it particularly suitable for optimizing the forming accuracy and density of micro and nanostructures. It can produce micron-sized metal structures with clear outlines and dimensional accuracy controlled at the submicron level, making it suitable for single-piece customization and small-batch microstructure production. However, the laser accelerates the hydrolysis of the electrolyte, resulting in a shorter electrolyte replacement cycle compared to mask electrodeposition.

[0008] In the field of laser-enhanced electrodeposition, patent CN103590080A discloses a rapid prototyping device for laser-enhanced jet electrodeposition, which follows a moving platform for printing. Simultaneously, electrolyte and laser are directed through a tubular anode towards the cathode deposition area. The interaction of the laser and the jet promotes mass transfer in the deposition area, thus increasing the deposition rate. The copper deposition rate for laser-enhanced electrodeposition is 10 μm / s, while that for laser-enhanced jet electrodeposition can reach 50 μm / s. Moreover, metal deposition occurs only in the laser-irradiated area, exhibiting good localization. However, this approach also struggles to achieve multi-electrode operation. As the number of electrodes increases, the laser cannot cover the entire deposition area, thus requiring a single electrode. While the "laser + jet" method accelerates the deposition rate, the biggest problem with single-electrode operation is its limited processing speed and difficulty in achieving area electroforming additive manufacturing.

[0009] Therefore, there is a need to provide an improved technical solution that addresses the shortcomings of the existing technology. Summary of the Invention

[0010] The purpose of this application is to provide a laser-enhanced area electroforming additive manufacturing apparatus and method to solve or alleviate the problems existing in the prior art.

[0011] To achieve the above objectives, this application provides the following technical solution: A laser-enhanced area electroforming additive manufacturing apparatus includes an electroforming power supply, a central control system, a circulation system, a laser system, an electroforming tank, an area array micro-jet printhead mounted inside and above the electroforming tank, a cathode substrate disposed below the area array micro-jet printhead, and a cathode drive system for driving the cathode substrate to move up and down and reciprocate within the electroforming tank; the circulation system, the area array micro-jet printhead, and the cathode drive system are all controlled by the central control system; the central control system includes a switching module; the cathode substrate does not contact the inner wall or bottom of the electroforming tank. The array micro-jet printhead includes a liquid storage housing, an array micro-jet plate fixed to the bottom surface of the liquid storage housing, and a light-transmitting window fixed to the top surface of the liquid storage housing; the array micro-jet plate includes a plate body and a plurality of micro-nozzles fixed in a matrix array on the plate body; the inner wall of the micro-nozzles is coated with a platinum black layer as an insoluble anode; the liquid storage housing and the electroforming tank are respectively filled with electrolyte, and the electrolyte level in the electroforming tank is below the upper surface of the cathode substrate; The positive terminal of the electroforming power supply is connected to the platinum black layer of each micro-nozzle via a switching module and several wires. The independent on / off control function of the switching module enables independent control of each micro-nozzle. The negative terminal of the electroforming power supply is connected to the cathode substrate. When the switching path of the corresponding micro-nozzle is turned on, an electrodeposition circuit can be formed between the platinum black layer (anode) of the micro-nozzle and the cathode substrate. The circulation system includes a filter pump and pipelines. The filter pump pumps the electrolyte in the electroforming tank into the liquid storage shell and provides working pressure for the micro nozzle. The laser system includes a laser generator placed to the side and a beam shaping module installed on the top surface of the micro-inkjet print head; the laser beam emitted by the laser generator is shaped into a linear laser beam by the beam shaping module and passes through the electrolyte and micro-nozzles in the liquid storage shell through the light transmission window before vertically irradiating the cathode substrate; the linear laser beam covers all micro-nozzles.

[0012] Furthermore, the linear laser beam is a rectangular laser beam with a center wavelength of 415~473nm and a blue flat-top beam. Its output line length is 110mm and its line width is 0.4~2mm. The uniformity of the energy field distribution along the length direction is >95%, which can completely cover the entire micro-nozzle without causing energy dispersion. The use of blue laser reduces the absorption of the linear laser beam by the electrolyte (which is blue due to the presence of copper sulfate).

[0013] Furthermore, the micro-nozzle is shaped like a trumpet, wider at the top and narrower at the bottom, and the outlet of the micro-nozzle is square or circular. The side length or diameter of the outlet of the micro-nozzle is 0.005mm to 0.05mm, and the center distance of the micro-nozzle is 0.1mm to 0.5mm.

[0014] Furthermore, the upper surface of the area array micro-spraying plate is coated with a protective layer to protect the area array micro-spraying plate from laser damage; the protective layer avoids the micro-nozzles; the protective layer is made of one or more of black silicon, silicon carbide, diamond-like carbon film, titanium nitride, and black zirconium oxide.

[0015] Furthermore, the positive terminal of the electroforming power supply is electrically connected to the platinum black layer of each micro-nozzle through several wires embedded in the body of the micro-spraying plate, and these wires are insulated from each other; the body of the micro-spraying plate is made of an acid and alkali resistant electrical insulating material with a thickness of 0.1mm to 0.5mm.

[0016] Furthermore, the laser-enhanced area electroforming additive manufacturing apparatus also includes a support, on which the cathode substrate is fixed; the support is installed in the cathode drive system; the support has a certain thickness, and the level of the electrolyte in the electroforming tank is between the lower surface and the upper surface of the support.

[0017] Furthermore, the cathode substrate is made of transition metals or transition metal alloys, such as copper, nickel, or stainless steel, and the area array micro-spraying plate is made of monocrystalline silicon; the electrolyte formula is: CuSO4·5H2O: 220g / L, H2SO4: 140g / L, NaCl: 82mg / L. Furthermore, a temperature control unit is installed inside the electrolyte storage shell. The temperature control unit includes a temperature measuring unit for detecting the temperature of the electrolyte inside the storage shell and a heating unit for heating; the temperature control unit and the heating unit are electrically connected to the main control system; when the electrolyte temperature inside the storage shell is lower than the set temperature, the heating unit is activated for heating; when the electrolyte temperature inside the storage shell is higher than the set temperature, the heating unit is turned off; during operation, the electrolyte in the electroforming tank is continuously fed into the area array micro-spraying printhead for its use, so simply turning off the heating unit is sufficient to cool the electrolyte inside the storage shell.

[0018] Furthermore, the cathode driving system drives the cathode substrate to move at a speed of 5 mm / s to 500 mm / s; the distance between the upper surface of the cathode substrate and the lower surface of the micro-spraying plate is controlled by the cathode driving system within the range of 0.05 to 0.5 mm.

[0019] The present invention also proposes a laser-enhanced area electroforming additive manufacturing method, using the aforementioned laser-enhanced area electroforming additive manufacturing apparatus, comprising the following steps: S1. Select the travel distance of the cathode substrate according to the printing plane and outline dimensions of the structural part to be printed; S2. Determine the printing resolution X×Y based on the ratio Y=L / w of the number of rows of array micro-nozzles in the area array micro-jet printhead and the moving stroke of the cathode substrate to the center distance of the array micro-nozzles. S3. Determine the printhead resolution X×R based on the number of columns and rows of micro-nozzles in the area array micro-jet printhead; S4. Slice the three-dimensional digital model of the structural component to be printed into slices of a certain thickness, obtain each slice, and divide the slice into X×Y grids. Assign values ​​to each grid with "0" and "1" according to the coordinates of each grid and whether the grid needs to be printed. "1" represents that it needs to be printed and "0" represents that it does not need to be printed, forming a two-dimensional digital matrix pixel information of X×Y composed of "0" and "1". S5. Load the linear laser beam onto the micro-printer head, add electrolyte to the liquid storage shell, and spray it evenly from the micro-nozzle. At the same time, start the electroforming power supply and cathode drive system. S6. Load the two-dimensional digital matrix pixel information of each slice into the central control system of the laser-enhanced area electroforming additive manufacturing device. The central control system extracts the real-time printing information of X×R in real time based on the two-dimensional digital matrix pixel information of X×Y and the position parameter information of the cathode substrate. Based on the real-time printing information, the system controls the on or off state of the micro-nozzle of X×R in real time through the connecting wire. Start the central control system to begin the area electroforming additive manufacturing of the first slice. After completion, raise the cathode substrate by one layer height. S7. Following a similar approach to S6, the second, third, ... Nth slices are sequentially fabricated using electroforming additive manufacturing driven by the three-dimensional digital model. S8. After all the set layers have been completed in the area electroforming additive manufacturing, turn off the electroforming power supply, circulation system, main control system and cathode drive system, remove the area electroforming additive manufacturing structural parts, and clean and dry them.

[0020] The technical solution of this application has the following beneficial effects: The apparatus and method of this application can significantly improve deposition rate and production efficiency. First, this patent supplies electrolyte to the electrodeposition micro-area (on the cathode substrate) via jet injection through micro-nozzles. This rapid and sufficient supply leads to fast mass transfer, and the electrolytic products are easily removed under the action of the rapid jet, thereby significantly increasing the limiting current density and limiting electrodeposition rate. Second, the irradiation heat from the linear laser in the electrolyte increases the local electrolyte temperature within the micro-jet anode, creating a temperature gradient. This increases the diffusion rate of charged particles and induces natural convection, thus increasing the electrochemical reaction rate and facilitating the depolarization effect of the cathode, thereby improving the electrodeposition rate. Third, the cathode substrate of this invention continuously reciprocates relative to the micro-jet printhead, resulting in a continuous liquid shear effect between the platinum black layer (anode) of the micro-nozzle and the cathode substrate. This drives electrolyte renewal and product removal, further accelerating the electrodeposition rate. Fourth, the cathode substrate of this patent moves back and forth continuously and significantly relative to the print head. The printable area mainly depends on the size of the cathode area or the stroke of the reciprocating movement, and is not limited by the size, dimensions and area of ​​the anode. Therefore, the printing production efficiency is greatly improved, and large-sized parts can be processed at the same time.

[0021] The apparatus and method of this application can significantly improve printing resolution and forming accuracy. The small size of the micronozzles allows for the printing of feature sizes as small as a few micrometers. Combined with laser irradiation, this further enhances the selectivity of electrodeposition, resulting in a printing resolution far exceeding that of existing area electroforming manufacturing methods. Furthermore, since each micronozzle is independently electrically connected to the electroforming power supply, the applied voltage or current can be precisely controlled independently or collaboratively, further improving printing resolution.

[0022] The apparatus and method of this application can obtain structural components with higher performance, and the performance of the structural components is more easily controlled. Electroforming additive manufacturing technology based on the principle of electrodeposition has advantages such as integrated forming and shaping, easy online adjustment of process conditions and parameters, dense material, low internal stress during forming, and fewer defects. Therefore, the comprehensive mechanical properties of its components are generally better. This application further superimposes a laser with outstanding grain refinement effect in the electrodeposition region, which is more conducive to enhancing the performance of electroforming additive components. Attached Figure Description

[0023] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. Wherein: Figure 1 This is a schematic diagram of the structure of a laser-enhanced area electroforming additive manufacturing apparatus according to an embodiment of the present invention.

[0024] Figure 2This is a side view of the laser-enhanced area electroforming additive manufacturing apparatus according to an embodiment of the present invention.

[0025] Figure 3 This is a schematic diagram of the structure of the area array micro-inkjet printhead according to an embodiment of the present invention.

[0026] Figure 4 This is a schematic diagram of the structure of the area array micro-spraying plate according to an embodiment of the present invention.

[0027] Figure 5 This is a schematic diagram of the structure of the array micro-nozzle according to an embodiment of the present invention.

[0028] Figure 6 This is a schematic diagram of two-dimensional digital matrix pixel information in the laser-enhanced area electroforming additive manufacturing method according to an embodiment of the present invention.

[0029] Figure 7 This is a cross-sectional schematic diagram of a structural component to which this invention applies.

[0030] Figure 8 This is a schematic diagram of the working process of the laser-enhanced area electroforming additive manufacturing apparatus in an embodiment of the present invention.

[0031] Figure 9 This is a schematic diagram of the switch module according to an embodiment of the present invention.

[0032] Explanation of reference numerals in the attached figures: 1. Electroforming tank; 2. Electrolyte; 3. Cathode substrate; 4. Electroforming power supply; 5. Area array micro-jet printhead; 51. Area array micro-jet plate; 511. Micro nozzle; 512. Connecting wire; 513. Protective layer; 514. Platinum black layer; 515. Real-time printing information; 52. Liquid storage shell; 53. Light transmission window; 54. Liquid inlet; 55. Temperature measuring unit; 6. Beam shaping module; 61. Laser generator; 7. Liquid outlet; 8. Filter pump; 9. Structural component; 10. Central control system; 101. Two-dimensional digital matrix pixel information; 102. Layer cutting; 11. Cathode drive system; 111. First slide rail; 112. First slider; 113. Second slide rail; 114. Second slider; 115. Third slide rail; 116. Third slider; 117. Connecting arm; 12. Support. Detailed Implementation

[0033] The present application will now be described in detail with reference to the accompanying drawings and embodiments. Various examples are provided by way of explanation and not by way of limitation. In fact, those skilled in the art will recognize that modifications and variations can be made to the present application without departing from the scope or spirit thereof. For example, a feature shown or described as part of one embodiment may be used in another embodiment to produce yet another embodiment. Therefore, it is desirable that the present application encompass such modifications and variations that fall within the scope of the appended claims and their equivalents.

[0034] In the following description, the terms "first / second / third" are used merely to distinguish similar objects and do not represent a specific order of objects. It is understood that "first / second / third" may be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used herein is for the purpose of describing embodiments of this disclosure only and is not intended to limit this disclosure.

[0036] In the description of this application, the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and do not require this application to be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0037] like Figures 1 to 5As shown, a laser-enhanced area electroforming additive manufacturing apparatus includes an electroforming power supply 4, a central control system 10, a circulation system, a laser system, an electroforming tank 1, an area array micro-jet printhead 5 mounted in the electroforming tank 1, a cathode substrate 3 disposed below the area array micro-jet printhead 5, and a cathode drive system 11 for driving the cathode substrate 3 to move up and down and reciprocate within the electroforming tank 1; the cathode substrate 3 does not contact the inner wall or bottom of the electroforming tank 1; the area array micro-jet printhead 5 includes a liquid storage housing 52, an area array micro-jet plate 51 fixed to the bottom surface of the liquid storage housing 52, and a light-transmitting window 53 sealed and fixed to the top surface of the liquid storage housing 52; The array micro-spraying plate 51 includes a plate body and a plurality of micro-nozzles 511 fixed on the plate body in a matrix array; the inner wall of the micro-nozzles 511 is coated with a platinum black layer 514 as an insoluble anode; the liquid storage shell 52 and the electroforming tank 1 are respectively filled with electrolyte 2, and the liquid level of the electrolyte 2 in the electroforming tank 1 is below the upper surface of the cathode substrate 3; the cathode driving system 11 drives the cathode substrate 3 to move at a speed of 5 mm / s to 500 mm / s; the distance between the upper surface of the cathode substrate 3 and the lower surface of the array micro-spraying plate 51 is controlled by the cathode driving system 11 within the range of 0.05 to 0.5 mm; The positive terminal of the electroforming power supply 4 is electrically connected to the platinum black layer 514 of each micro-nozzle 511 via a switching module and several wires. The independent on / off control function of the switching module is used to realize the independent control of each micro-nozzle 511. The negative terminal of the electroforming power supply 4 is electrically connected to the cathode substrate 3. The main modules of the overall control system include a control module and a host computer; the host computer can be a system based on programmable control chips such as CPU and SOC, such as a computer, smartphone, tablet computer, or embedded development system, which is equipped with a processing system for 3D model slicing, visualization interface display, parameter control, and generation of control programs. The control module is a development board based on microcontrollers such as STM32 / ESP32 / 89C51. As a lower-level machine, it is mainly used to control and receive control programs sent by the upper-level machine and send real-time monitoring data during the printing process to the upper-level machine. The communication methods between the upper-level machine and the control module can be bus communication, Wi-Fi communication, Bluetooth communication, etc. The control module mainly includes a microcontroller, a switch module, a temperature control module, and a motion control module. The switch module consists of a column serial-to-parallel converter chip, a row serial-to-parallel converter chip, and logic switch units corresponding to the array micro-nozzles. The row / column serial-to-parallel converter chip converts the serial signal input by the microcontroller into a parallel signal, realizes port expansion, and controls the array logic switch units row by row or column by column. When the logic switch unit is turned on, the electroforming power supply and the output terminal are turned on, and the current forms a path between the electrolyte sprayed by the micro-nozzle and the cathode substrate to realize electrodeposition. Figure 9 The diagram above illustrates a switch module corresponding one-to-one with a 4×12 array of micro-nozzles. The circulation system includes a filter pump 8 and pipelines. The filter pump 8 pumps the electrolyte 2 in the electroforming tank 1 into the liquid storage shell 52 and provides working pressure for the micro nozzle 511. The spray flow rate of a single nozzle is 5~20ml / min, with a preferred value of 10ml / min. The laser system includes a laser generator 61 placed to the side and a beam shaping module 6 mounted on the top surface of the area array micro-inkjet printhead 5; the laser beam emitted by the laser generator 61 is shaped into a linear laser beam by the beam shaping module 6 and passes through the light transmission window 53 through the electrolyte 2 in the liquid storage housing 52 and the micro-nozzle 511 before vertically irradiating the cathode substrate 3; the linear laser beam covers all the micro-nozzles 511.

[0038] The linear laser beam is a rectangular laser beam with a blue, flat-topped shape and a center wavelength of 415-473nm. Its output line length is 110mm, linewidth is 0.4-2mm, and the energy field distribution uniformity along its length is >95%, ensuring complete coverage of the entire micro-nozzle 511 without energy dispersion. The use of a blue laser reduces the absorption of the linear laser beam by the electrolyte 2 (which is blue due to the presence of copper sulfate). The laser generator 61 can be a BLF-455 series blue semiconductor laser from the Guangdong-Hong Kong-Macao Greater Bay Area Hard Technology Innovation Research Institute (Hard Technology Institute), such as BLF-455-800 (center wavelength 455nm, power 800W) or BLD-455-1000 (center wavelength 455nm, power 1000W). The laser beam emitted by laser generator 61 is shaped into a rectangular spot by beam shaping module 6. This beam shaping technology is existing technology, and the following beam shaping schemes can be adopted: ① Diffraction shaping scheme: The "circular Gaussian beam → 110mm × 3mm flat-top rectangle" conversion is achieved through collimation and beam expansion + customized rectangular flat-top diffraction optical element (DOE). ② DMD digital light processing shaping system: The working principle is similar to a projector. It uses the pixel-level reflection control of DMD chip (millions of micro mirrors) to reflect the Gaussian beam into a 110mm × 3mm rectangular pixel array. The reflection intensity of each pixel is adjusted by algorithm to achieve flat-top energy distribution and supports dynamic adjustment of spot size / shape. ③ Fiber coupling shaping scheme: The circular Gaussian laser is injected into a customized rectangular core diameter fiber through a coupler. When the laser propagates in the fiber, it is constrained into a rectangle by the core diameter. After exiting, it is calibrated into a 110mm × 3mm flat-top spot by an asymmetric collimating lens. ④ Microlens array (MLA) shaping system: Energy homogenization is achieved by relying on geometric refraction. A Gaussian beam is divided into thousands of tiny sub-beams using an asymmetric microlens array. These sub-beams are then filtered by a rectangular aperture, and finally superimposed on the target surface to form a flat-topped rectangular beam spot. The beam shaping module in this application is custom-designed from a manufacturer (such as the Institute of Hard Science), which provides the solution.

[0039] like Figures 3 to 5As shown, the micro-nozzle 511 is shaped like a trumpet, wider at the top and narrower at the bottom. The outlet of the micro-nozzle 511 is square or circular, and the side length or diameter of the outlet is 0.005mm to 0.05mm. It can print feature sizes as fine as several micrometers, and each micro-nozzle can be controlled independently or collaboratively, resulting in high printing resolution. The center-to-center distance of the micro-nozzles 511 is 0.1mm to 0.5mm. Existing MEMS technology has already been able to scale the micro-nozzles 511 to 1μm or even sub-micrometer levels.

[0040] The upper surface of the area array micro-spraying plate 51 is coated with a protective layer 513 to protect the area array micro-spraying plate 51 from laser damage; the protective layer 513 avoids the micro-nozzle 511; the protective layer 513 is made of one or more of black silicon, silicon carbide, diamond-like film, titanium nitride, and black zirconium oxide.

[0041] The positive electrode of the electroforming power supply 4 is electrically connected to the platinum black layer 514 of each micro-nozzle 511 through several wires embedded in the plate body of the micro-spraying plate 51. These wires are insulated from each other. The plate body of the micro-spraying plate 51 is made of an acid and alkali resistant electrical insulating material with a thickness of 0.1mm to 0.5mm.

[0042] The cathode substrate 3 is made of a metal with a conductivity of not less than 55%. The cathode substrate 3 is relatively thin, consisting of a pure copper plate with a thickness of 0.2mm to 1.5mm (e.g., 0.2mm, 0.3mm, 0.5mm, 0.8mm, 0.9mm, 1mm, 1.2mm, 1.5mm). Its function is to conduct electricity and provide support for the metal deposition structure. Other highly conductive materials can also be used instead, such as copper-clad aluminum foil, high-conductivity aluminum, copper-aluminum-copper three-layer composite plate, or silver-plated / copper stainless steel sheet. If the cathode substrate 3 is used as a disposable cathode, even thinner materials can be used, such as 0.1mm nickel foil or 0.2mm high-conductivity aluminum, which can be removed together with the workpiece after electroforming.

[0043] During the printing process, the cathode substrate 3 continuously reciprocates relative to the micro-jet printhead 5, resulting in a continuous liquid shearing effect between the anode of the micro-nozzle 511 and the cathode substrate. This drives the renewal of the electrolyte 2 and the discharge of the product, thereby accelerating the electrodeposition rate. The distance between the micro-nozzle 511 and the cathode substrate 3 is 0.05~0.5mm, and the moving speed of the cathode substrate 3 is 5mm / s~500mm / s. When the substrate reciprocates relative to the nozzle, the electrolyte 2 in the gap is dragged, creating a velocity gradient between the micro-nozzle 511 and the cathode substrate 3. The resulting mild Couette flow shearing achieves controllable compression of the diffusion layer, timely discharge of the product, and homogenization of the in-plane environment. At the same time, it reduces the diffusion layer thickness and enhances the mass transfer effect. Without increasing the complexity of the equipment (in a completely stationary state relative to the cathode substrate 3 and the micro-nozzle 511), the deposition rate can be increased by 20%~60%, the layer thickness uniformity can be improved by 3 times, and pinhole and scaling defects can be significantly reduced. It is suitable for precision electroforming additive manufacturing in the 10µm~1mm range.

[0044] like Figures 1 to 2 As shown, in order to movably mount the cathode substrate 3 within the electroforming tank 1, the laser-enhanced area electroforming additive manufacturing apparatus further includes a support 12, on which the cathode substrate 3 is fixed. The support 12 is mounted on the cathode drive system 11. The support 12 has a certain thickness, which is at least greater than the vertical movement distance of the cathode substrate. This thickness also ensures that even if the electrolyte 2 ripples due to the movement of the support 12, it will not splash onto the cathode substrate 3. The thickness of the support 12 can be 0.6~3 cm. m (e.g., 0.6cm, 0.7cm, 0.8cm, 1cm, 1.2cm, 1.3cm, 1.5cm, 1.6cm, 1.8cm, 2cm, 2.5cm, 3cm), the electrolyte level 2 in the electroforming tank 1 is always between the lower surface and the upper surface of the support 12; specifically, the height of the electrolyte 2 is controlled by opening an outlet 7 on the side wall of the electroforming tank, and the electrolyte 2 that reaches the height of the outlet 7 automatically flows out, the position of the outlet 7 corresponding to the middle position of the upper and lower range of the support 12. During the printing process, the support 12 drives the cathode substrate 3 to reciprocate, and the support 12 continuously agitates the electrolyte 2 in the electroforming tank 1, which helps to maintain the uniformity of the electrolyte 2 concentration, pH and temperature, and at the same time helps the electrolyte 2 and impurities in it to be discharged, thus assisting in improving the deposition quality.

[0045] Furthermore, the support 12 is made of an insulating non-metallic material that is acid-resistant, such as PVC (rigid polyvinyl chloride), PP (polypropylene), PTFE (Teflon), or CPVC (chlorinated polyvinyl chloride) engineering plastics; the support 12 may be partially hollow or entirely hollow. The micro-spraying plate 51 is made of monocrystalline silicon; the light-transmitting window 53 is made of high-transmittance quartz glass; the electrolyte 2 formula is: CuSO4·5H2O: 220g / L, H2SO4: 140g / L, NaCl: 82mg / L.

[0046] A temperature control unit is installed inside the liquid storage shell 52. The temperature control unit includes a temperature measuring unit 55 for detecting the temperature of the electrolyte 2 inside the liquid storage shell 52 and a heating unit for heating. The temperature control unit and the heating unit are electrically connected to the temperature control module. When the temperature of the electrolyte 2 inside the liquid storage shell 52 is lower than the set temperature, the heating unit is activated to heat it. When the temperature of the electrolyte 2 inside the liquid storage shell 52 is higher than the set temperature, the heating unit is turned off. During operation, the electrolyte 2 in the electroforming tank 1 is continuously fed into the micro-jet printhead 5 for its use, so the cooling of the electrolyte 2 inside the liquid storage shell 52 can be achieved simply by turning off the heating unit.

[0047] This invention significantly improves deposition rate, production efficiency, printing resolution, and forming accuracy, in the following aspects: 1) The micro-nozzle delivers electrolyte to the electrodeposition micro-area in a jet manner, resulting in rapid and sufficient electrolyte supply and fast mass transfer. Furthermore, the electrolytic products under the action of the rapid jet are easily discharged, significantly increasing the limiting current density and limiting electrodeposition rate. 2) The heat from the linear laser beam irradiation is absorbed by the electrolyte in the storage tank, causing localized heating of the electrolyte and forming a temperature gradient. This increases the diffusion rate of charged particles while inducing millimeter-level natural convection, thus increasing the electrochemical reaction rate and facilitating the depolarization effect of the cathode, thereby improving the electrodeposition rate. 3) The reciprocating motion of the cathode substrate relative to the micro-jet printhead creates a liquid shear effect between them, driving electrolyte renewal and product discharge, thereby accelerating the electrodeposition rate. 4) The disturbance of the electrolyte in the electroforming tank by the support promotes the discharge and homogenization of electrolyte impurities, contributing to improved deposition quality. 5) The small size of the micro-nozzles, combined with the irradiation of the linear laser beam, further improves the selectivity of electrodeposition, resulting in a printing resolution far exceeding that of existing area electroforming manufacturing methods. 6) The individual or collaborative digital precision control of each micro-nozzle enables higher molding accuracy.

[0048] In one specific embodiment, the cathode substrate 3 is made of pure copper, and the micro-nozzle 511 is tapered, wider at the top and narrower at the bottom, with a circular inlet of 0.05 mm in diameter and a circular outlet of 0.03 mm in diameter. Its inner wall is coated with a 500 nm thick platinum black layer 514 as an insoluble anode. The center-to-center distance of the micro-nozzles 511 (center-to-center distance within...) Figure 4The thickness of the protective layer 513 is 0.1 mm (marked as w); the protective layer 513 is made of black silicon with a thickness of 500 nm and is deposited in the area between the micro-nozzles 511; the area array micro-spraying plate 51 is horizontally sealed and fixed to the bottom end face of the liquid storage shell 52; the light-transmitting window 53 is horizontally sealed and fixed to the top end of the liquid storage shell 52; the area array micro-spraying plate 51 is made of single crystal silicon with a thickness of 0.2 mm and is fabricated using MEMS (Micro-Electro-Mechanical Systems) technology. The platinum black layer 514 of each micro-nozzle 511 is independently electrically connected to the connecting wire 512. The positive terminal of the electroforming power supply 4 is electrically connected to the connecting wire 512 through the main control system 10 to control the on / off state of the electrode, i.e., the platinum black layer 514; the connecting wire 512 is embedded inside the area array micro-spraying plate 51 and is insulated from each other; the negative terminal of the electroforming power supply 4 is electrically connected to the cathode substrate 3.

[0049] The cathode substrate 3 is mounted below the area array micro-spraying plate 51 via the cathode driving system 11, and can move horizontally and precisely back and forth. Its travel distance can be adjusted according to the dimensions of the structural component 9. Preferably, the initial distance between the upper surface of the cathode substrate 3 and the lower surface of the area array micro-spraying plate 51 is 0.2 mm. The control terminal of the cathode driving system 11 is connected to the motion control module of the main control system. The cathode driving system 11 uses a suitable precision three-axis slide table, which is a mature existing device. Figure 2 The description only covers the settings of the main components (slide rails, slide tables / slider): such as Figure 2 As shown, a typical three-axis slide table mounting structure includes a longitudinal first slide rail 111 mounted on the two long sides of the top of the electroforming tank 1 via a bracket, a transverse second slide rail 113 mounted on the first slide rail 111 via a first slider 112, and a vertical third slide rail 115 mounted on the second slide rail 113 via a second slider 114; a connecting arm 117 is fixed to one side of the support 12, and the upper end of the connecting arm 117 is mounted on the third slide rail 115 via a third slider 116.

[0050] The filter pump 8 serves both as a conveyor of electrolyte 2 and a filter, and can also be a combination of a pump and a filter. The upper side of the liquid storage shell 52 is provided with an inlet 54, and the lower middle part of the electrolytic cell is provided with an outlet 7 corresponding to the position of the support 12. The outlet end of the filter pump 8 is connected to the inlet 54, and the return end of the filter pump 8 is connected to the outlet 7. The electrolyte 2 in the electroforming tank 1 is sent to the micro-jet print head 5 by the filter pump 8. The micro-jet print head sprays out the electrolyte 2, forming a circulation of electrolyte 2.

[0051] by Figure 8 Taking the structural component shown as an example, the method of laser-enhanced area electroforming additive manufacturing is illustrated, including the following steps: S1. Select the printing plane of the structural part to be printed, measure the outline size of the printing plane of the workpiece, the outline size is 30×30mm, and determine the moving stroke of the cathode substrate to be 40mm based on the outline size. S2. Based on the ratio of the number of rows of micro-nozzles in the array micro-jet printhead (400 rows) and the moving stroke of the cathode substrate (40 mm) to the center distance of the array micro-nozzles (0.1 mm), the printing resolution is determined to be 400×400. S3. Based on the number of columns (400 columns) and rows (40 rows) of the micro-nozzles in the area array micro-jet printhead, determine the printhead resolution to be 400×40. S4. Import the 3D digital model of the structural component to be printed into the host computer and slice it with a thickness of 0.1mm to obtain each slice. Divide each slice into X×Y grids. Assign values ​​to each grid with "0" and "1" according to the coordinates of each grid and whether the grid needs to be printed. "1" represents that it needs to be printed and "0" represents that it does not need to be printed, forming a two-dimensional digital matrix pixel information of X×Y composed of "0" and "1". Figure 6 for Figure 7 A schematic diagram of the pixel information of a two-dimensional digital matrix of structural components. S5. Start the filter pump to add electrolyte into the micro-jet printhead through the inlet and provide working pressure to make the electrolyte spray out evenly from the micro nozzle. Load the linear laser beam onto the micro-jet printhead. At the same time, start the electroforming power supply, cathode substrate drive system and temperature control unit to adjust the electrolyte temperature to 35℃. S6. Load the two-dimensional digital matrix pixel information of each slice into the control module of the laser-enhanced area electroforming additive manufacturing device. The overall control system, based on the 400×400 two-dimensional digital matrix pixel information and the position parameter information of the cathode substrate (in... Figure 8 Marked as 101), extracting real-time printing information of 400×40 (in Figure 8 Marked as 515), based on real-time printing information, the power supply to the 400×40 array micro-nozzles is controlled in real-time via connecting wires, activating the central control system to begin the first layer cutting (in Figure 8 The area marked 102) is electroformed additively manufactured, and after completion, the cathode substrate is lifted by one layer height (0.2 mm) by a cathode drive system. Figure 8 The lower middle section schematically illustrates several real-time printing information required to print a slice; S7. Following a similar approach to S6, the second, third...120th slices are sequentially fabricated using electroforming additive manufacturing under the drive of the three-dimensional digital model. S8. After all the set layers have been completed in the area electroforming additive manufacturing, turn off the electroforming power supply, circulation system, main control system and cathode drive system, take out the area electroforming additive manufacturing structural parts, clean and dry them, and complete all steps.

[0052] The electroforming additive manufacturing method based on the electrodeposition principle employed in this application has advantages such as integrated forming and shaping, easy online adjustment of process conditions and parameters, dense material, low internal stress during forming, and fewer defects, resulting in generally good comprehensive mechanical properties of the manufactured parts. Furthermore, this application superimposes a laser with a significant grain-refining effect in the electrodeposition region and designs the cathode substrate and support within the electroforming tank to be reciprocating, further enhancing the performance of the electroformed additive parts.

[0053] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A laser-enhanced area electroforming additive manufacturing apparatus, characterized in that: The system includes an electroforming power supply, a central control system, a circulation system, a laser system, an electroforming tank, a micro-printer head mounted inside the electroforming tank, a cathode substrate positioned below the micro-printer head, and a cathode drive system that drives the cathode substrate to move up and down and reciprocate within the electroforming tank. The cathode substrate does not contact the inner wall or bottom of the electroforming tank. The circulation system, the micro-printer head, and the cathode drive system are all controlled by the central control system. The central control system includes a switching module. The array micro-jet printhead includes a liquid storage housing, an array micro-jet plate fixed to the bottom surface of the liquid storage housing, and a light-transmitting window fixed to the top surface of the liquid storage housing; the array micro-jet plate includes a plate body and a plurality of micro-nozzles fixed in a matrix array on the plate body; the inner wall of the micro-nozzles is coated with a platinum black layer as an insoluble anode; the liquid storage housing and the electroforming tank are respectively filled with electrolyte, and the electrolyte level in the electroforming tank is below the upper surface of the cathode substrate; The positive terminal of the electroforming power supply is connected to the platinum black layer of each micro-nozzle via a switching module and several wires. The independent on / off control function of the switching module enables independent control of each micro-nozzle. The negative terminal of the electroforming power supply is connected to the cathode substrate. The circulation system includes a filter pump and pipelines. The filter pump pumps the electrolyte in the electroforming tank into the liquid storage shell and provides working pressure for the micro nozzle. The laser system includes a laser generator placed to the side and a beam shaping module installed on the top surface of the micro-inkjet print head; the laser beam emitted by the laser generator is shaped into a linear laser beam by the beam shaping module and passes through the electrolyte and micro-nozzles in the liquid storage shell through the light transmission window before vertically irradiating the cathode substrate; the linear laser beam covers all micro-nozzles.

2. The laser-enhanced area electroforming additive manufacturing apparatus according to claim 1, characterized in that: The linear laser beam is a flat-top beam with an output line length of 110 mm and a line width of 0.4-2 mm. It is a blue laser with a center wavelength of 415-473 nm and its energy field distribution uniformity along its length is >95%.

3. The laser-enhanced area electroforming additive manufacturing apparatus according to claim 1, characterized in that: The micro-nozzle is shaped like a trumpet, wider at the top and narrower at the bottom. The outlet of the micro-nozzle is square or circular, and the side length or diameter of the outlet of the micro-nozzle is 0.005mm to 0.05mm. The center distance of the micro-nozzle is 0.1mm to 0.5mm.

4. The laser-enhanced area electroforming additive manufacturing apparatus according to claim 1, characterized in that: The upper surface of the micro-spraying plate is coated with a protective layer to protect the micro-spraying plate from laser damage; the protective layer avoids the micro-nozzles; the protective layer is made of one or more of the following materials: black silicon, silicon carbide, diamond-like carbon film, titanium nitride, and black zirconium oxide.

5. The laser-enhanced area electroforming additive manufacturing apparatus according to claim 1, characterized in that: The positive terminal of the electroforming power supply is electrically connected to the platinum black layer of each micro-nozzle through several wires embedded in the body of the micro-spraying plate. These wires are insulated from each other. The body of the micro-spraying plate is made of an acid and alkali resistant electrical insulating material with a thickness of 0.1mm to 0.5mm.

6. The laser-enhanced area electroforming additive manufacturing apparatus according to claim 1, characterized in that: It also includes a support, on which the cathode substrate is fixed; the support is installed in the cathode drive system; the support has a certain thickness, and the level of the electrolyte in the electroforming tank is between the lower surface and the upper surface of the support.

7. The laser-enhanced area electroforming additive manufacturing apparatus according to claim 6, characterized in that: The support is made of non-metallic material, the cathode substrate is made of transition metal or transition metal alloy, and the micro-spraying plate is made of single-crystal silicon; the electrolyte formula is: CuSO4·5H2O: 220g / L, H2SO4: 140g / L, NaCl: 82mg / L.

8. The laser-enhanced area electroforming additive manufacturing apparatus according to claim 1, characterized in that: A temperature control unit is installed inside the liquid storage shell. The temperature control unit includes a temperature measuring unit for detecting the temperature of the electrolyte inside the liquid storage shell and a heating unit for heating. The temperature control unit and the heating unit are electrically connected to the main control system. When the temperature of the electrolyte inside the liquid storage shell is lower than the set temperature, the heating unit is activated to heat the electrolyte. When the temperature of the electrolyte inside the liquid storage shell is higher than the set temperature, the heating unit is deactivated.

9. The laser-enhanced area electroforming additive manufacturing apparatus according to claim 1, characterized in that: The cathode driving system drives the cathode substrate to move at a speed of 5 mm / s to 500 mm / s; the distance between the upper surface of the cathode substrate and the lower surface of the micro-spray plate is controlled by the cathode driving system within the range of 0.05 to 0.5 mm.

10. A laser-enhanced method for surface region electroforming additive manufacturing, characterized in that: Using the laser-enhanced area electroforming additive manufacturing apparatus as described in any one of claims 1-9, the process includes the following steps: S1. Select the travel distance of the cathode substrate according to the printing plane and outline dimensions of the structural part to be printed; S2. Determine the printing resolution X×Y based on the ratio Y=L / w of the number of rows of array micro-nozzles in the area array micro-jet printhead and the moving stroke of the cathode substrate to the center distance of the array micro-nozzles. S3. Determine the printhead resolution X×R based on the number of columns and rows of micro-nozzles in the area array micro-jet printhead; S4. Slice the three-dimensional digital model of the structural component to be printed into slices of a certain thickness, obtain each slice, and divide the slice into X×Y grids. Assign values ​​to each grid with "0" and "1" according to the coordinates of each grid and whether the grid needs to be printed, where "1" represents that it needs to be printed and "0" represents that it does not need to be printed, forming a two-dimensional digital matrix pixel information of X×Y composed of "0" and "1". S5. Load the linear laser beam onto the micro-printer head, the circulation system adds electrolyte to the liquid storage shell and sprays it evenly from the micro-nozzle. At the same time, start the electroforming power supply and cathode drive system. S6. Load the two-dimensional digital matrix pixel information of each slice into the central control system of the laser-enhanced area electroforming additive manufacturing device. The central control system extracts the real-time printing information of X×R in real time based on the two-dimensional digital matrix pixel information of X×Y and the position parameter information of the cathode substrate. Based on the real-time printing information, the system controls the on or off state of the micro-nozzle of X×R in real time through the connecting wire. Start the central control system to begin the area electroforming additive manufacturing of the first slice. After completion, raise the cathode substrate by one layer height. S7. Following a similar approach to S6, the second, third... Nth slices are sequentially fabricated using electroforming additive manufacturing driven by the three-dimensional digital model. S8. After all the set layers have been completed in the area electroforming additive manufacturing, turn off the electroforming power supply, circulation system, main control system and cathode drive system, remove the area electroforming additive manufacturing structural parts, and clean and dry them.

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