Method and device for rapid additive manufacturing of high-precision metal microstructures by light-controlled liquid film tip

Abstract

The application discloses a method and device for rapidly adding a high-precision metal microstructure by using a light-controlled liquid film tip, and relates to the technical field of special processing. The method comprises the following steps: adding a photosensitive electrolyte into a hollow glass tube; forming a photosensitive droplet at the end of the hollow glass tube due to the surface tension of the liquid; changing the shape of the photosensitive droplet by using low-power laser irradiation, so as to change the electrochemical processing gap; and finally making the end of the photosensitive droplet contact the workpiece, so as to realize tip processing. The application also provides a device capable of realizing the method of the application, and improves the localization and precision of electrochemical additive manufacturing.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of composite processing in special processing technology, and particularly to a method and device for light-controlled liquid film tip rapid additive manufacturing of high-precision metal microstructure. BACKGROUND

[0002] With the rapid development of aerospace technology, micro-electro-mechanical system, mobile communication and other high-tech, the requirements for the size and precision of parts are increasing. Traditional manufacturing technology cannot meet the needs of the development of parts, so additive manufacturing has been paid more and more attention. Additive manufacturing includes laser additive manufacturing, electron beam additive manufacturing, electrochemical additive manufacturing and the like. Among them, electrochemical additive manufacturing is a processing technology that uses electrochemical cathode deposition principle for forming. Compared with laser additive manufacturing and electron beam additive manufacturing, electrochemical additive manufacturing technology can be processed at room temperature, has no thermal defects, the processing scale belongs to ion-level processing, has high forming precision, can obtain nanometer plated metal structure, and does not need support during processing, has become a research hotspot at home and abroad, and has very broad application prospect.

[0003] Although the electrochemical additive manufacturing technology has many advantages as described above, the flow of electrolyte during deposition can greatly reduce the forming precision of the part. At the same time, stray deposition also makes it difficult to electrodeposit parts with complex shapes. In addition, electrochemical additive manufacturing also has the problems of low processing rate and the like. This leads to the fact that electrochemical additive manufacturing is currently mainly applied to the forming of very simple microstructure, and cannot fully exert the advantages of electrochemical additive manufacturing technology.

[0004] Domestic and foreign scholars have carried out in-depth research on the problems existing in the current electrochemical additive manufacturing technology and proposed a series of new process methods. For example, jet electrodeposition technology, localized electrodeposition technology, meniscus constrained electrodeposition technology and the like. However, the theoretical research of these technologies is not perfect enough, and a large amount of simulation and experimental research is still needed. How to improve the localization and forming precision during deposition has become a key problem to be solved in electrochemical additive manufacturing technology. SUMMARY

[0005] In view of the deficiencies in the prior art, the present application provides a method and device for light-controlled liquid film tip rapid additive manufacturing of high-precision metal microstructure. By introducing photosensitive electrolyte in electrochemical additive manufacturing, and using laser irradiation to change the shape of the photosensitive liquid drop at the end of the hollow glass tube to change the electrochemical processing gap, the lower end of the photosensitive liquid drop is in contact with the workpiece to realize tip processing, and the high heat of the laser makes it evaporate, realizing localized processing of electrochemical additive manufacturing. The present application improves the localization and precision of electrochemical additive manufacturing.

[0006] The present application achieves the above technical purpose through the following technical means.

[0007] The method for light-controlled liquid film tip rapid additive manufacturing of high-precision metal microstructure adds photosensitive electrolyte in a hollow glass tube, a photosensitive liquid drop is formed at the end of the hollow glass tube due to the surface tension of the liquid, low-power laser irradiation is used to change the shape of the photosensitive liquid drop, thereby changing the electrochemical processing gap, and finally the end of the photosensitive liquid drop is in contact with the workpiece, so that tip processing is realized; high-power laser irradiation is used to evaporate the photosensitive electrolyte, and localized processing of electrochemical additive manufacturing is realized.

[0008] In the above scheme, the low-power laser is not more than 1000 watts, and the high-power laser is more than 1000 watts.

[0009] In the above scheme, the hollow glass tube is a tapered tube, and the ball diameter at the end of the hollow glass tube is 10-100 microns.

[0010] The device of the method for light-controlled liquid film tip rapid additive manufacturing of high-precision metal microstructure comprises a computer, a metal wire, a laser, a hollow glass tube and a power supply; the hollow glass tube is internally provided with the metal wire and photosensitive electrolyte; the upper end of the hollow glass tube is clamped by an anode clamp, and a certain processing gap exists between the lower end of the hollow glass tube and the workpiece; the laser beam emitted by the laser changes the propagation path through a two-dimensional scanning galvanometer and irradiates on the photosensitive electrolyte drop hung at the end of the hollow glass tube; the metal wire is connected with the positive electrode of the power supply, and the negative electrode of the power supply is connected with the workpiece.

[0011] In the above scheme, the photosensitive electrolyte is a metal cation aqueous solution containing trimethylammonium bromide azobenzene surfactant.

[0012] In the above scheme, the hollow glass tube is a quartz glass tube.

[0013] In the above scheme, the hollow glass tube installed on the anode clamp can realize Z-direction movement; and the workpiece installed on the workbench can realize X and Y-direction movement.

[0014] In the above scheme, the hollow glass tube is obtained by winding a resistance wire on the surface of a glass tube, hanging a weight at the end, connecting the resistance wire with the power supply to heat the glass tube, and stretching the glass tube under the action of the weight gravity, so that the hollow glass tube with a tapered shape is obtained.

[0015] In the above scheme, the processing gap is 10-100 microns.

[0016] In the above scheme, the power supply is a high-frequency pulse power supply, and the output voltage range is 0-24V.

[0017] The beneficial effects of the present application are:

[0018] 1. The present application utilizes the surface tension of the photosensitive droplet at the end of the hollow glass tube to achieve small-area contact with the surface of the workpiece, and then realizes droplet tip processing, with high processing precision, avoiding stray deposition, and being conducive to the formation of complex patterns and precision structures, with a simple process and easy implementation.

[0019] 2. In the present application, the surface tension of the liquid is changed by laser beam irradiation, or the end photosensitive droplet is evaporated by high heat of the laser, so that the rate of electrodeposition reaction and the occurrence and stop of electrodeposition reaction are controllable, high flexibility processing can be realized, and the forming precision of microstructure is improved.

[0020] 3. The power, spot size and laser frequency of the laser beam can be adjusted, so that the photosensitive droplet has multiple forms, and the electrochemical additive manufacturing technology can adapt to various processing requirements.

[0021] 4. In the present application, the metal wire is placed as a tool anode inside the hollow glass tube, due to the insulation effect of the hollow glass tube, the electric field generated by the anode is limited within the range of the outlet of the hollow glass tube, which reduces the electric field action range between the workpiece and improves the localization of electrochemical additive manufacturing.

[0022] 5. In the present application, laser beam irradiation is introduced in the electrodeposition process, which can change the shape of the photosensitive droplet while forming a micro-area stirring by the thermal effect of the laser beam, strengthening the liquid mass transfer effect to ensure the concentration of metal cations at the photosensitive droplet, thereby ensuring the deposition rate of the electrodeposition reaction.

[0023] 6. In the present application, the movement of the workbench, the movement of the anode clamp, and the movement of the laser focal point position are all controlled by the computer system, thereby ensuring the accuracy of each processing position and the precision of electrochemical additive manufacturing. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The schematic diagram of the light-controlled liquid film tip rapid additive high-precision metal surface microstructure device involved in the embodiment of the present application;

[0025] Figure 2 The Figure 1 The local enlarged schematic view at A;

[0026] Figure 3 The Figure 1 The preparation process schematic diagram of the hollow glass tube involved in the present application;

[0027] Figure 4 The schematic diagram of the influence of the laser beam on the shape of the photosensitive droplet involved in the embodiment of the present application;

[0028] Figure 5A schematic diagram of a process for rapid additive high-precision metal surface microstructure processing of a light-controlled liquid film tip is shown in the examples of the present application.

[0029] Figure 6 A schematic diagram of a flexible metal surface microstructure array is shown.

[0030] Figure 7 A schematic diagram of a traditional electrochemical additive manufacturing processing result is shown.

[0031] Figure 8 A schematic diagram of a structure processed by the method of the present application is shown.

[0032] Reference signs:

[0033] 1 - computer system; 2 - metal wire; 3 - photosensitive electrolyte; 4 - two-dimensional scanning galvanometer; 5 - laser beam; 6 - laser; 7 - worktable; 8 - base; 9 - workpiece; 10 - photosensitive droplet; 11 - hollow glass tube; 12 - power supply; 13 - column; 14 - anode clamp; 15 - weight; 16 - resistance wire; 17 - glass tube; 18 - deposit. DETAILED DESCRIPTION

[0034] Embodiments of the present application are described in detail below with reference to the attached drawing figures, wherein the same or like reference numerals and characters in the drawings and the following description denote the same or similar functions. The embodiments described below are merely exemplary for the purpose of explaining the present application and are not to be understood as a limitation of the present application.

[0035] In the description of the present application, it needs to be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "axial", "radial", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the purpose of facilitating the description of the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0036] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and other terms should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0037] In conjunction with the accompanying Figure 1 and 2 As shown in the figure, the hollow glass tube 11 is provided with a photosensitive electrolyte 3 of trimethylammonium bromide azobenzene surfactant and a metal wire 2, and a photosensitive droplet 10 is formed at the end of the hollow glass tube 11 due to the surface tension of the liquid. The tip of the photosensitive droplet 10 contacts the workpiece 9, and an electrochemical reaction system is formed in the contact area. In the non-contact area, due to the lack of photosensitive electrolyte 3, electrodeposition reaction cannot occur. Under the action of the laser beam 5, the morphology of the photosensitive droplet 10 will change controllably, thereby affecting the processing gap and the processing area. Increasing the power of the laser beam 5 can realize the controllable stop of the electrochemical reaction by evaporating the photosensitive droplet 10 with heat, thereby improving the localization and flexibility of the electrodeposition reaction.

[0038] The realization of the light-controlled droplet is through the isomerization of the surfactant molecules in the solution under the action of the laser beam 5, thereby affecting the surface tension of the entire solution, and the photosensitive droplet 10 at the end of the hollow glass tube 11 will also change accordingly, thereby controlling the processing gap and the contact area between the photosensitive droplet 10 and the workpiece 9 during processing, and ensuring the localization and precision of processing.

[0039] When the power of the laser beam 5 is increased, such as when the laser power exceeds 1000 watts, the critical power will cause the photosensitive droplet 10 to evaporate directly due to heat, and at this time no electrochemical reaction occurs. When it is necessary to move from one deposition area to another deposition area, deposition reaction can be avoided in the area where deposition is not needed, thereby avoiding the destruction of the precision and quality of electrochemical additive manufacturing.

[0040] The hollow glass tube 11 is a tapered glass tube obtained by heating the glass tube 17 by the resistance wire 16, and then drawing the heated glass tube 17 by relying on the gravity of the weight 15. It can ensure that the size of the photosensitive droplet 10 is not too large, and at the same time store more electrolyte solution to avoid the formation of ion deficiency area, and ensure the normal occurrence of electrochemical reaction during processing.

[0041] The photosensitive electrolyte 3 is formed by adding trimethylammonium bromide azobenzene surfactant in the aqueous solution of traditional metal cations. The surfactant exhibits trans structure under visible light, and changes into cis structure when it is irradiated by ultraviolet light, and then restores into trans structure again under visible light. And the surface tension of the surfactant changes correspondingly when the isomerization occurs, and affects the whole solution, so the photosensitive droplet 10 can be controlled by the laser beam 5 to realize the light-controlled droplet tip processing.

[0042] The laser beam 5 should be ultraviolet laser with wavelength of 360±5nm, and the surfactant in the photosensitive electrolyte 3 is most sensitive to the ultraviolet laser in the wavelength range, which can ensure the rapid change of the form of the photosensitive droplet 10 and the accuracy of the processing area. The output spot of the ultraviolet laser is small, which can be accurately acted on the photosensitive droplet 10, avoiding the thermal influence on the processed area when the laser energy is too large, and ensuring the precision and quality of electrochemical additive manufacturing.

[0043] The hollow glass tube 11 is made of quartz glass, which has good insulation performance and can limit the electric field generated by the metal wire 2 at the end of the outlet of the hollow glass tube 11, avoiding stray corrosion. The reflectivity of quartz glass to laser is high, which reduces or even eliminates the thermal influence of the laser beam 5 on the photosensitive electrolyte 3 in the hollow glass tube 11, thereby reducing the influence of temperature on the surface tension and ensuring the controllability of the form of the photosensitive droplet 10 and the locality of electrochemical additive manufacturing.

[0044] The hollow glass tube 11 is installed on the anode clamp 14, which can move in Z direction on the column 13; the workpiece 9 is fixed on the workbench 7, which can move in X and Y directions on the base 8, and the movement of the anode clamp 14 and the workbench 7 are controlled by the computer system 1 without manual intervention, which can realize the processing of various complex shapes and improve the locality and processing precision.

[0045] All kinds of parameters of the laser beam 5, such as power and frequency, are controlled by the computer system 1, by which the precise control of the photosensitive droplet 10 is realized to ensure the processing precision and quality.

[0046] The drawings are attached Figures 1-2As shown, first fill the photosensitive electrolyte 3 into the hollow glass tube 11, and put the metal wire 2 into the hollow glass tube 11, and install them together on the anode clamp 14, at this time the photosensitive droplet 10 is formed at the end of the hollow glass tube 11 due to the effect of liquid surface tension, adjust the position of the anode clamp 14 so that the tip of the photosensitive droplet 10 is in contact with the workpiece 9, and connect the metal wire 2 and the workpiece 9 to the positive and negative poles of the power supply 12 respectively. Precisely adjust the workpiece 9, the anode clamp 14 and the two-dimensional scanning galvanometer 4 by the computer system 1 to reach the initial state of processing to start processing, and during the processing, the Z direction movement of the anode clamp 14 on the column 13, the X and Y direction movement of the workbench 7 on the base, the adjustment of the two-dimensional scanning galvanometer 4 and the power and frequency parameters of the laser beam 5 are all precisely controlled by the computer system 1 without manual intervention.

[0047] In combination with the accompanying drawings Figure 3 As shown, since the tip of the photosensitive droplet 10 is needed for localized processing, the end of the hollow glass tube 11 should be as small as possible, so the glass tube 17 is stretched to become a conical hollow glass tube 11, and the ball diameter of the end of the hollow glass tube is 10-100 microns to meet the process requirements. The resistance wire 16 is wound on the glass tube 17, and the weight 15 is hung at the end of the glass tube 17, and when the resistance wire 16 is connected to the power supply, the glass tube 17 is heated due to the heat effect of the current passing through the resistance body, and is gradually stretched into a conical structure under the action of the gravity of the weight 15, and when the process requirements are met, the power supply is turned off and the weight 15 is removed.

[0048] In combination with the accompanying drawings Figures 4-6 As shown, the surface microstructure array of the flexible metal device is relatively complex, the sizes of the patterns are different, and there is no stray deposition in the non-deposition area, which requires that the shape of the photosensitive droplet 10 can be changed arbitrarily and the path of the electrochemical reaction can be eliminated when necessary. Under the irradiation of the laser beam 5, the change of the liquid surface tension caused by the cis-trans isomerization of the trimethylammonium bromide azobenzene surfactant makes the shape of the photosensitive droplet 10 change. When the power of the laser beam 5 reaches a certain degree, the photosensitive droplet 10 can be completely evaporated, at this time the electrochemical reaction system has no conductive path and the electrochemical reaction stops. In this period, the liquid phase mass transfer effect has not stopped, which is beneficial to eliminate the concentration polarization caused by the electrochemical reaction and ensure the normal progress of the subsequent electrodeposition reaction. And at this time the deposition area can be adjusted to achieve the effect of no deposition in the non-deposition area, meet the process requirements of the flexible metal surface microstructure array, and improve the localization and flexibility of electrochemical additive manufacturing.

[0049] In combination with the accompanying drawings Figure 7 And 8 As shown, Figure 7The traditional electrochemical additive manufacturing is shown in the schematic diagram. The deposition reaction occurs in a larger area than the anode area, with poor localization and a small aspect ratio of the obtained deposit 18. Figure 8 The schematic diagram of the method of the present application is shown. The electrodeposition reaction only occurs in the contact area between the photosensitive droplet 10 and the workpiece 9, with good localization and an improved aspect ratio of the obtained deposit 18. The computer system 1 is used to accurately control the processing trajectory, and precise complex structures can be processed.

[0050] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily mean the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0051] Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those skilled in the art can make changes, modifications, replacements and variations to the above embodiments without departing from the principles and spirit of the present application within the scope of the present application.

Claims

1. A method of light-controlled liquid film tip rapid additive manufacturing of high-precision metal microstructures, characterized in that, The photosensitive electrolyte (3) is a metal cation aqueous solution containing trimethylammonium bromide azobenzene surfactant. A photosensitive droplet is formed at the end of the hollow glass tube (11) due to the effect of liquid surface tension. The morphology of the photosensitive droplet is changed by low-power laser irradiation to change the electrochemical processing gap. Finally, the end of the photosensitive droplet is in contact with the workpiece to realize tip processing. High-power laser irradiation makes the photosensitive electrolyte evaporate to control the occurrence and stop of electrochemical reaction, and realize localized processing of electrochemical additive manufacturing.

2. The method of claim 1, wherein, The low-power laser is not more than 1000 watts, and the high-power laser is more than 1000 watts.

3. The method of claim 1, wherein, The hollow glass tube is a tapered tube, and the ball diameter at the end of the hollow glass tube is 10-100 microns.

4. An apparatus for implementing the method of claim 1 to 3 for fast additive manufacturing of high-precision metal microstructures with light-controlled liquid film tip, characterized in that, The system comprises a computer (1), a metal wire (2), a laser (6), a hollow glass tube (11), and a power supply (12). The hollow glass tube (11) contains a metal wire (2) and a photosensitive electrolyte (3). The upper end of the hollow glass tube (11) is clamped by an anode clamp (14), and there is a certain processing gap between the lower end of the hollow glass tube (11) and the workpiece (9). The laser beam (5) emitted by the laser (6) is irradiated on the photosensitive electrolyte droplet hanging at the end of the hollow glass tube (11) after changing the propagation path by a two-dimensional scanning galvanometer (4). The metal wire (2) is connected to the positive electrode of the power supply (12), and the negative electrode of the power supply (12) is connected to the workpiece (9).

5. The apparatus of claim 4, wherein, The hollow glass tube (11) is a quartz glass tube.

6. The apparatus of claim 4, wherein, The hollow glass tube (11) is installed on the anode clamp (14) to realize Z-direction movement. The workpiece (9) is installed on the workbench (7) to realize X and Y-direction movement.

7. The apparatus of claim 4, wherein, The hollow glass tube (11) is obtained by winding a resistance wire (16) on the surface of a glass tube (17), hanging a weight (15) at the end, and connecting the resistance wire (16) to the power supply to heat the glass tube (17), so that it is stretched under the gravity of the weight (15), thereby obtaining a tapered hollow glass tube (11).

8. The apparatus of claim 4, wherein, The processing gap is 10-100 microns.

9. The apparatus of claim 4, wherein, The power supply (12) is a high-frequency pulse power supply with an output voltage range of 0-24V.

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