Nanosecond laser processing method and fixture for super-hydrophobic surface of ultra-fine metal wire

Abstract

The invention discloses a nanosecond laser processing method and fixture for the super-hydrophobic surface of an ultra-fine metal wire. The method comprises the following steps: cutting the ultra-fine metal wire to a desired length, polishing the surface of the ultra-fine metal wire with sandpaper, ultrasonically cleaning the surface with deionized water, and drying the surface; clamping the pre-treated ultra-fine metal wire to a fixture; etching the ultra-fine metal wire with a wavelength of 1064 nm, a repetition frequency of 20 kHz, a pulse duration of 100 ns, and a spot diameter of about 50 μm, wherein the parameters of the nanosecond laser processing are a power of 3 to 15 W, a scanning speed of 300 to 700 mm / s, and a scanning number of 1 to 5 times; immersing the laser-processed ultra-fine metal wire in a fluorosilane ethanol solution and then drying the ultra-fine metal wire. The method realizes the processing of the super-hydrophobic structure on the surface of the ultra-fine metal wire, ensures the processing quality, and has the advantages of simple method, low cost, good material versatility, no generation of toxic substances and gases, and low environmental pollution.

Description

Technical Field

[0001] The present invention relates to the technical field of material surface treatment, and in particular to a nanosecond laser processing method and a fixture for the super-hydrophobic surface of an ultra-fine metal wire. Background Art

[0002] Ultrafine metal wires with a diameter of less than 500 microns have important application prospects in the fields of drag reduction, anti-fouling, anti-icing, oil-water separation, etc. However, the small diameter and cylindrical outer contour make it difficult to process. Currently, only a few methods can be used to process hydrophobic surfaces on ultrafine metal wires. Zhang et al. used acidic ferric chloride solution to chemically etch copper wire to construct a microstructure, and then used octadecyl mercaptan to modify it to reduce the surface energy, and finally obtained a super-hydrophobic surface with a contact angle of 151° (Journal of Chromatography A, 2022, 1670: 462948.). Wang et al. first used a 90°C hydrothermal method to prepare zinc oxide nanorod arrays on the surface of stainless steel wire mesh, and then immersed it in a polydimethylsiloxane solution to reduce the surface energy, obtaining a super-hydrophobic stainless steel wire mesh (ACS Applied Materials & Interfaces, 7 (47), 2015: 26184-26194.). Song et al. used a one-step electrospraying method to directly construct a super-hydrophobic coating on the surface of a metal wire (Marine Pollution Bulletin, 2016, 113 (1-2): 211-215.). Liu et al. first arranged polystyrene microspheres with a diameter of 1 micron on the surface of a copper wire to form a microsphere array template, then deposited copper in the gaps of the microsphere array by electrochemical deposition, and finally used tetrahydrofuran to dissolve the microsphere array template to leave a copper microstructure, thereby obtaining a hydrophobic surface (Langmuir, 2022, 38 (8): 2711-2719.). Although the above method can be used to process super-hydrophobic surfaces on ultrafine metal wires, there are still problems such as complex process, high cost, poor material versatility, large environmental pollution, and low processing efficiency. Summary of the Invention

[0003] The present invention provides a nanosecond laser processing method and a fixture for the super-hydrophobic surface of an ultra-fine metal wire to solve the above-mentioned problem.

[0004] In order to achieve the above object, the technical solution of the present invention is:

[0005] A nanosecond laser processing method for a super-hydrophobic surface of an ultra-fine metal wire comprises the following steps:

[0006] S1: Cut the ultrafine metal wire into the required length, polish the surface of the ultrafine metal wire with sandpaper, then ultrasonically clean it with deionized water and blow dry the ultrafine metal wire to complete the pretreatment;

[0007] S2: Clamp the pre-treated ultra-fine metal wire onto the fixture;

[0008] S3: A nanosecond laser with a wavelength of 1064 nm, a repetition rate of 20 kHz, a pulse duration of 100 ns, and a spot diameter of approximately 50 μm is used to etch an ultrafine metal wire to construct a microstructure. The parameters of the nanosecond laser processing are a power of 3 W to 15 W, a scanning speed of 300 mm / s to 700 mm / s, and 1 to 5 scans. The ultrafine metal wire is rotated by a rotating fixture to achieve zoned processing of the ultrafine metal wire surface. After each zone is processed, the fixture rotates the metal wire once until single laser processing of all zones is completed.

[0009] S4: Immerse the laser-processed ultrafine metal wire in a fluorosilane ethanol solution and then dry it to complete the nanosecond laser processing of the super-hydrophobic surface of the ultrafine metal wire.

[0010] Furthermore, the mass fraction of the fluorosilane ethanol solution is 1 wt%.

[0011] Furthermore, the drying condition is: drying at 80° C. for 20 minutes.

[0012] Furthermore, the material of the ultrafine metal wire is copper, aluminum, iron, titanium and alloys thereof.

[0013] Furthermore, the ultrafine metal wire is a metal wire with a diameter not exceeding 500 μm.

[0014] A fixture used in the nanosecond laser processing method for the super-hydrophobic surface of an ultra-fine metal wire comprises a first fixture and a second fixture of identical structure, wherein the first fixture and the second fixture are arranged front and back to clamp the front and rear ends of the ultra-fine metal wire respectively;

[0015] The first clamp and the second clamp each include a base, a dividing wheel and a nut, the base is provided with a dividing wheel mounting groove, the dividing wheel mounting groove is provided with a through hole, and the dividing wheel mounting groove is provided with a positioning protrusion;

[0016] The indexing wheel is disc-shaped, and a wire clamping hole is provided in the center of the indexing wheel. Four slots are evenly distributed around the disk surface of one side of the indexing wheel, and a threaded hole is provided on the disk surface of the other side of the indexing wheel. When processing ultra-fine metal wire, the indexing wheel is installed in the indexing wheel installation slot, and the positioning protrusion is provided in one of the slots. The two ends of the ultra-fine metal wire respectively pass through the through hole and are clamped in the metal wire clamping hole, and the end of the ultra-fine metal wire extending from the metal wire installed in the clamping hole is tightened by the nut installed in the threaded hole.

[0017] After each 1 / 4 area of ​​the ultrafine metal wire surface is processed, the dividing wheel 1 is rotated 90° around the axis to drive the ultrafine metal wire to rotate 90° around its axis to process the next 1 / 4 area of ​​the ultrafine metal wire surface.

[0018] The beneficial effects of the present invention are:

[0019] The present invention discloses a nanosecond laser processing method for super-hydrophobic surfaces of ultra-fine metal wires. The process is simple, no expensive chemical reagents are required, and the cost is low. The super-hydrophobic surfaces can be processed on ultra-fine wires of metals such as copper, aluminum, iron, titanium, and their alloys, so the material has good versatility; no toxic chemical gases are generated or emitted, so the environmental pollution is small; the processing efficiency is high, and the microstructure required for super-hydrophobicity can be constructed on the surface of the ultra-fine metal wire in just a few minutes. At the same time, the surface of the ultra-fine metal wire is processed in a zoned manner, which effectively avoids repeated processing of the same area, ensures the processing uniformity of the surface of the ultra-fine metal wire, and improves the processing quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 is a schematic diagram of the fixture;

[0022] Figure 2 is a schematic diagram of the base structure;

[0023] Figure 3 It is a dividing wheel Figure 1 ;

[0024] Figure 4 It is a dividing wheel Figure 2 ;

[0025] Figure 5 This is an electron microscope image of the super-hydrophobic surface of the ultra-fine brass wire obtained under the processing conditions of 6W power, 500mm / s scanning speed, and 1 scanning number in Example 1;

[0026] Figure 6 This is a contact angle diagram of a 5 μL water droplet on the super-hydrophobic surface of an ultra-fine brass wire obtained under the processing conditions of 6 W power, 500 mm / s scanning speed, and 1 scanning number in Example 1.

[0027] In the picture:

[0028] 1. Base; 11. Indexing wheel mounting slot; 12. Limiting protrusion; 13. Through hole;

[0029] 2. Indexing wheel; 21. Slot; 22. Threaded hole; 23. Wire clamping hole;

[0030] 3. Nut;

[0031] 4. Gasket;

[0032] 5. Ultra-fine metal wire. DETAILED DESCRIPTION

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0034] The principles involved in this application are:

[0035] First, cut the metal wire to a certain length, and then polish, ultrasonically clean with deionized water, and dry it to completely remove other impurities on the surface of the metal wire to avoid affecting the results of subsequent laser processing. Then clamp the pretreated metal wire on the fixture to keep the metal wire taut to ensure that the surface of the metal wire can evenly absorb the laser energy during laser processing. The angle of each rotation of the metal wire is accurately controlled by the dividing wheel to be 90° (a total of 3 rotations) to ensure that the surface of the metal wire can evenly form a micro / nano composite structure under the action of the laser. Finally, soak the laser-processed metal wire in a 1wt% fluorosilane ethanol solution to graft the silane groups in the fluorosilane molecules to the surface of the metal wire, reduce the surface energy of the material, and bake it at high temperature (80°C) to promote a stronger bond between the fluorosilane molecules and the surface, so that it has long-lasting superhydrophobic properties.

[0036] Example

[0037] Example 1:

[0038] S1: Pretreatment: A brass wire with a diameter of 200 μm was cut into 12 cm pieces, and then polished with 1200# and 2000# sandpaper respectively. Then, it was ultrasonically cleaned with deionized water for 2 minutes and dried to complete the pretreatment process;

[0039] The fixture structure used in this method is as follows Figure 1-4 As shown, it comprises a first clamp and a second clamp of the same structure, wherein the first clamp and the second clamp are arranged front and back to clamp the front and back ends of the ultra-fine metal wire respectively;

[0040] The first clamp and the second clamp each include a base 1, a dividing wheel 2 and a nut 3. The base is provided with a dividing wheel mounting groove 11, a through hole 13 is provided in the dividing wheel mounting groove, and a positioning protrusion 12 is provided on the dividing wheel mounting groove.

[0041] The indexing wheel 1 is disc-shaped, and a wire clamping hole 23 is provided in the center of the indexing wheel 1. Four slots 21 are evenly distributed around the disk surface of one side of the indexing wheel 2, and a threaded hole 22 is provided on the disk surface of the other side of the indexing wheel 2. When processing the ultra-fine metal wire 5, the indexing wheel 2 is installed in the indexing wheel installation groove 11, and the positioning protrusion 12 is provided in one of the slots 21. The two ends of the ultra-fine metal wire 5 respectively pass through the through hole 13 and are clamped in the metal wire clamping hole 23, and the end of the ultra-fine metal wire extending from the metal wire installed in the clamping hole 23 is tightened by the nut 3 installed in the threaded hole.

[0042] S2: Clamping process: The brass wire is passed through the through hole of the base and the wire clamping hole of the indexing wheel, the wire is tightened, and the end of the wire extending from the wire clamping hole is clamped and fixed by a nut installed in the threaded hole and a gasket provided between the wire and the nut;

[0043] S3: After the ultrafine metal wire is fixed, laser processing is performed, specifically: a nanosecond laser with a wavelength of 1064nm, a repetition frequency of 20kHz, a pulse duration of 100ns, and a spot diameter of about 50μm is used to etch the brass wire to construct a microstructure; the nanosecond laser processing parameters are power 6W, scanning speed 500mm / s, and scanning number 1. After completing the processing of 1 / 4 area of ​​the ultrafine metal wire surface, the nut is loosened, and the dividing wheel is removed from the dividing wheel mounting groove in the axial direction, and then the dividing wheel 1 is rotated 90° around the axis, driving the ultrafine metal wire 5 to rotate 90° around its axis, and processing the next 1 / 4 area of ​​the ultrafine metal wire surface. The micromorphology of the brass wire surface after laser processing is as follows: Figure 5 As shown;

[0044] S4: Low surface energy treatment: The laser processed brass wire was immersed in a 1wt% fluorosilane ethanol solution and then dried at 80°C for 20 minutes. The contact angle of a water droplet on the superhydrophobic brass wire is shown in Figure 4. Figure 6 As shown in the figure, using a laser power of 6W, a scanning speed of 500mm / s, and a scan count of 1, a spike-like microstructure can be produced on the brass surface. According to the Cassie-Baxter model, the theoretical superhydrophobicity should be significantly improved. Experimental measurements are consistent with this theory, achieving a contact angle of 156°, demonstrating excellent superhydrophobicity.

[0045] Example 2:

[0046] The only difference between this embodiment and embodiment 1 is that in this embodiment, the nanosecond laser processing parameters are: power 3W, scanning speed 500mm / s, and number of scans 1. The contact angle of the processed ultrafine metal wire was measured to be 144°.

[0047] Example 3:

[0048] The only difference between this embodiment and embodiment 1 is that in this embodiment, the nanosecond laser processing parameters are: power 9W, scanning speed 500mm / s, and number of scans 1. The contact angle of the processed ultrafine metal wire was measured to be 150°.

[0049] Example 4:

[0050] The only difference between this embodiment and embodiment 1 is that in this embodiment, the nanosecond laser processing parameters are: power 12W, scanning speed 500mm / s, and number of scans 1. The contact angle of the processed ultrafine metal wire was measured to be 147°.

[0051] Example 5:

[0052] The only difference between this embodiment and embodiment 1 is that in this embodiment, the nanosecond laser processing parameters are: power 15W, scanning speed 500mm / s, and number of scans 1. The contact angle of the processed ultrafine metal wire was measured to be 148°.

[0053] Example 6:

[0054] The only difference between this embodiment and embodiment 1 is that in this embodiment, the nanosecond laser processing parameters are: power 6W, scanning speed 300mm / s, and number of scans 1. The contact angle of the processed ultrafine metal wire was measured to be 154°.

[0055] Example 7:

[0056] The only difference between this embodiment and embodiment 1 is that in this embodiment, the nanosecond laser processing parameters are: power 6W, scanning speed 400mm / s, and number of scans 1. The contact angle of the processed ultrafine metal wire was measured to be 153°.

[0057] Example 8:

[0058] The only difference between this embodiment and embodiment 1 is that in this embodiment, the nanosecond laser processing parameters are: power 6W, scanning speed 600mm / s, and number of scans 1. The contact angle of the processed ultrafine metal wire was measured to be 148°.

[0059] Example 9:

[0060] The only difference between this embodiment and embodiment 1 is that in this embodiment, the nanosecond laser processing parameters are: power 6W, scanning speed 700mm / s, and number of scans 1. Test measurements of the processed ultrafine metal wire showed a contact angle of 140°.

[0061] Example 10:

[0062] The only difference between this embodiment and embodiment 1 is that in this embodiment, the nanosecond laser processing parameters are: power 6W, scanning speed 500mm / s, and number of scans 2. The contact angle of the processed ultrafine metal wire was measured to be 156°.

[0063] Example 11:

[0064] The only difference between this embodiment and embodiment 1 is that in this embodiment, the nanosecond laser processing parameters are: power 6W, scanning speed 500mm / s, and number of scans 3. The contact angle of the processed ultrafine metal wire was measured to be 153°.

[0065] Example 12:

[0066] The only difference between this embodiment and embodiment 1 is that in this embodiment, the nanosecond laser processing parameters are: power 6W, scanning speed 500mm / s, and number of scans 4. The contact angle of the processed ultrafine metal wire was measured to be 138°.

[0067] Example 13:

[0068] The only difference between this embodiment and embodiment 1 is that in this embodiment, the nanosecond laser processing parameters are: power 6W, scanning speed 500mm / s, and number of scans 5. The contact angle of the processed ultrafine metal wire was measured to be 148°.

[0069] Comparative Example

[0070] Comparative Example 1:

[0071] The only difference between this comparative example and Example 1 is that in this comparative example, the nanosecond laser processing parameters are: power 1.5W, scanning speed 500mm / s, and number of scans 1. The contact angle of the processed ultrafine metal wire was measured to be 142°.

[0072] Comparative Example 2:

[0073] The only difference between this comparative example and Example 1 is that in this comparative example, the nanosecond laser processing parameters are: power 16.5W, scanning speed 500mm / s, and number of scans 1. The contact angle of the treated ultrafine metal wire was measured to be 149°.

[0074] Comparative Example 3:

[0075] The only difference between this comparative example and Example 1 is that in this comparative example, the nanosecond laser processing parameters are: power 6W, scanning speed 200mm / s, and number of scans 1. The contact angle of the processed ultrafine metal wire was measured to be 151°.

[0076] Comparative Example 4:

[0077] The only difference between this comparative example and Example 1 is that in this comparative example, the nanosecond laser processing parameters are: power 6W, scanning speed 800 mm / s, and number of scans 1. Test measurements of the treated ultrafine metal wire showed a contact angle of 140°.

[0078] Comparative Example 5:

[0079] The only difference between this comparative example and Example 1 is that in this comparative example, the nanosecond laser processing parameters are: power 6W, scanning speed 500mm / s, and number of scans 6. The contact angle of the processed ultrafine metal wire was measured to be 140°.

[0080] The processing parameters and results of Examples 1-13 and Comparative Examples 1-5 are shown in the following table:

[0081]

[0082]

[0083] It can be seen from the data in the above table that the processing of the super-hydrophobic structure on the surface of the ultrafine metal wire can be achieved only within the range of the processing parameters provided by the present invention, that is, a better processing effect can be achieved within the range of power 3W to 15W, scanning speed 300mm / s to 700mm / s, and number of scans 1 to 5 times, wherein there is no difference between processing 2 times and processing 1 time. Considering the processing cost, the optimal processing parameters are the power 6W, scanning speed 500mm / s, and number of scans 1 in Example 1.

[0084] To sum up, the present invention realizes the zoned processing of the super-hydrophobic structure on the surface of the ultra-fine metal wire by setting a clamp, thereby improving the processing uniformity of the ultra-fine metal wire, and combined with the processing technology parameters set in this application, finally realizes the processing of the super-hydrophobic structure on the surface of the ultra-fine metal wire, ensuring the processing quality. This method has simple steps, low cost, good material versatility, does not produce toxic substances and gases, and has little environmental pollution.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A nanosecond laser processing method for super-hydrophobic surface of ultra-fine metal wire, characterized in that: The steps include: S1: Cut the ultrafine metal wire into the required length, polish the surface of the ultrafine metal wire with sandpaper, then ultrasonically clean it with deionized water and blow dry the ultrafine metal wire to complete the pretreatment; S2: Clamp the pre-treated ultra-fine metal wire onto the fixture; S3: A nanosecond laser with a wavelength of 1064 nm, a repetition rate of 20 kHz, a pulse duration of 100 ns, and a spot diameter of 50 µm was used to etch an ultrafine metal wire to construct a microstructure. The parameters of the nanosecond laser processing were power of 3 W to 15 W, a scanning speed of 300 mm / s to 700 mm / s, and one to five scans. The ultrafine metal wire was rotated by a rotating fixture to achieve zoned processing of the ultrafine metal wire surface. After each zone was processed, the fixture rotated the metal wire once until all zones were processed by a single laser. S4: Immerse the laser-processed ultrafine metal wire in a fluorosilane ethanol solution and then dry it to complete the nanosecond laser processing of the super-hydrophobic surface of the ultrafine metal wire.

2. The nanosecond laser processing method for super-hydrophobic surface of ultra-fine metal wire according to claim 1, characterized in that: The mass fraction of the fluorosilane ethanol solution is 1 wt %.

3. The nanosecond laser processing method for super-hydrophobic surface of ultra-fine metal wire according to claim 1, characterized in that: The drying conditions are: drying at 80 °C for 20 min.

4. The nanosecond laser processing method for super-hydrophobic surface of ultra-fine metal wire according to claim 1, characterized in that: The material of the ultra-fine metal wire is copper, aluminum, iron, titanium and alloys thereof.

5. The nanosecond laser processing method for super-hydrophobic surface of ultra-fine metal wire according to claim 4, characterized in that: The ultrafine metal wire is a metal wire with a diameter not exceeding 500 μm.

6. A fixture used in the nanosecond laser processing method for super-hydrophobic surface of ultra-fine metal wire according to claim 1, characterized in that: It comprises a first clamp and a second clamp of the same structure, wherein the first clamp and the second clamp are respectively arranged in front and back to clamp the front and back ends of the ultra-fine metal wire; The first clamp and the second clamp both comprise a base (1), a dividing wheel (2) and a nut (3); the base is provided with a dividing wheel mounting groove (11); a through hole (13) is provided in the dividing wheel mounting groove (11); and a positioning protrusion (12) is provided on the dividing wheel mounting groove; The dividing wheel (2) is in the shape of a circular disc, and a metal wire clamping hole (23) is provided at the center of the dividing wheel (2). Four slots (21) are evenly distributed around the disk surface of one side of the dividing wheel (2), and a threaded hole (22) is provided on the disk surface of the other side of the dividing wheel (2). When processing the ultrafine metal wire (5), the dividing wheel (2) is installed in the dividing wheel installation slot (11), and the positioning protrusion (12) is provided in one of the slots (21). The two ends of the ultrafine metal wire (5) respectively pass through the through hole (13) and are clamped in the metal wire clamping hole (23), and one end of the ultrafine metal wire extending out of the metal wire clamping hole (23) is pressed by the nut (3) installed in the threaded hole. After processing one quarter of the surface of the ultrafine metal wire, the dividing wheel (2) is rotated 90 degrees around the axis, driving the ultrafine metal wire (5) to rotate 90 degrees around its axis, thereby processing the next quarter of the surface of the ultrafine metal wire.

Images