A method for preparing super-hydrophobic surface by ultrasonic rolling nanoparticles

Abstract

The present invention provides a method for preparing a super-hydrophobic surface by ultrasonic rolling nanoparticles, which belongs to the technical field of metal hydrophobic surface preparation, comprising the steps of: pre-treating the alloy surface to make the surface roughness ≤0.5μm, performing ultrasonic cleaning, and drying; silanizing the nanoparticles, bonding the nanoparticles after the silanization treatment to the alloy surface using an adhesive; embossing the nanoparticles on the alloy surface using ultrasonic rolling; when embossing using ultrasonic rolling, the rolling head is radially pressed into the alloy surface, first rolling along a set path as a whole, and then rolling along a set path two to obtain a super-hydrophobic surface. The present invention realizes a one-step preparation of a hydrophobic texture through the high strain rate elastic-plastic deformation produced by ultrasonic rolling, while producing an ideal residual compressive stress on the surface of the part, and the material properties and texture strength are significantly improved, with higher reliability and mechanical stability.

Description

Technical Field

[0001] The invention belongs to the technical field of metal hydrophobic surface preparation, and in particular relates to a method for preparing a super-hydrophobic surface by ultrasonic rolling nanoparticles. Background Art

[0002] Wettability is a key property of solids. It refers to the ability or tendency of a liquid to spread on a solid surface and is crucial for studying the functionality of solid surfaces. The wettability of a solid surface is determined by both its surface chemical composition and micromorphology. It is typically measured by the contact angle of a liquid droplet on the solid surface. Upon contact, a liquid droplet typically appears as a sphere, hemisphere, or film. Tangents to the liquid-gas interface and the solid-liquid interface are drawn from the three-phase contact point, and the angle between these two tangents is the contact angle of the droplet on the solid surface. The contact angle is used as a criterion for determining the degree of wettability of a liquid on a solid surface, with 90° typically used as the cutoff point. When the contact angle is less than 90°, the surface is hydrophilic; when it is greater than 90°, the surface is hydrophobic. There are two extreme cases: when the contact angle approaches 0°, the surface is considered superhydrophilic; and when the contact angle is greater than 150°, the surface is considered superhydrophobic. In recent years, hydrophobic materials, especially superhydrophobic materials, have attracted attention and research from all walks of life due to their broad application prospects.

[0003] As an extreme exception to hydrophobicity, superhydrophobic surfaces can be used in many areas, such as self-cleaning, corrosion prevention, prevention of current conduction, and surface self-protection. Using superhydrophobic materials on the hulls or inner walls of ships and vessels can reduce friction with water flow and improve their corrosion resistance. Using them on materials such as ceramics, glass, and metals can achieve self-cleaning or easy-to-clean properties. Using them in microfluidic devices can facilitate low-resistance, leak-free transmission of fluids. With the continuous advancement of science and the continuous updating of research methods, people have higher requirements for material performance. Superhydrophobic surfaces, which have many practical values, have gradually attracted attention. The preparation and wettability research of superhydrophobic surfaces has become a research hotspot today.

[0004] With the continuous development of science and technology, people are inspired by the super-hydrophobic surfaces of animals and plants in nature and are constantly studying methods for preparing super-hydrophobic surfaces. According to wettability theory, the chemical composition and microstructure of the solid surface jointly determine its surface wettability. The surface chemical composition mainly affects the surface free energy, while the surface microstructure mainly affects the surface roughness of the solid. Therefore, improving the wettability of the solid surface to prepare a super-hydrophobic surface should be considered from two aspects. First, constructing micro-nano structures on the material surface to obtain a super-hydrophobic surface by changing the roughness; second, coating the material surface with low surface energy substances to obtain a super-hydrophobic surface by changing the surface free energy. At present, there have been many reports on the preparation methods of super-hydrophobic surfaces, such as etching, sol-gel method, vapor deposition method and template method, etc., which prepare super-hydrophobic surfaces by constructing rough structures on low surface energy materials or depositing low surface energy substances on rough structures. However, the mechanical stability of the micro-nano secondary structure of metal-based super-hydrophobic surfaces is generally poor, especially for nanoscale structures. Even slight physical contact and collision may cause damage to them. Furthermore, the wear of rough metal surface structures can easily lead to the loss of low-energy surface-modifying substances such as long-chain fatty acids and fluorosilanes, ultimately causing the superhydrophobic material to fail. Therefore, further improving the mechanical stability of the surface texture is expected to promote the practical application of metal-based superhydrophobic surfaces.

[0005] Chinese patent CN113604095A discloses a kind of porous powder of load super-hydrophobic particle and preparation method and application thereof, nano sol, ammoniacal liquor and aqueous hydrophobic treatment agent are scattered in deionized water, modified nano particle suspension is obtained, and super-hydrophobic modified nano particle powder is obtained by spray drying method; Porous micron ceramic powder, aqueous silane coupling agent are added in deionized water, super-hydrophobic modified nano particle powder is added, continuous stirring is made, the porous particle suspension of load super-hydrophobic particle, is dried by filtration or spray drying method and obtains the porous powder of load super-hydrophobic particle. Although this patent can prepare the porous powder of load super-hydrophobic particle, how to utilize powder to prepare super-hydrophobic coating and do not relate to, it is difficult to realize the practical application of the method.

[0006] Chinese patent CN111235520A discloses an ultrasonic rolling textured AlCrN coating on a substrate surface and its preparation process. The invention first performs ultrasonic rolling texturing on the surface of a substrate metal, and then prepares an AlCrN coating on the textured substrate metal surface. The ultrasonic rolling texturing process is as follows: during continuous ultrasonic rolling, the substrate metal moves a set distance along the -X direction, then a set distance along the +Y direction, and then a set distance along the +X direction to form an S-shaped tool path, and the single S-shaped tool path is repeated at least once to texture the substrate metal surface. This patent can significantly enhance the film-substrate bonding strength of the substrate metal, making its tribological properties more significantly improved, but the process cannot produce nanostructures and cannot achieve the preparation of superhydrophobic functional surfaces. Summary of the Invention

[0007] In response to the shortcomings of the prior art, the present invention provides a method for preparing a super-hydrophobic surface by ultrasonically rolling nanoparticles. The method utilizes the ultrasonic vibration and static pressure of ultrasonic rolling to produce high-strain-rate plastic deformation, inducing the silanized nanoparticles to be pressed and embedded into the textured surface, thereby achieving a one-step preparation of a multi-level textured surface with super-hydrophobic function. This method can simultaneously achieve the one-step preparation of alloy surface rolling strengthening and hydrophobic texture, and the strength and stability of the resulting hydrophobic texture are significantly improved compared to other preparation methods. The preparation method of the present invention is simple and effective, and can quickly prepare super-hydrophobic surfaces with micro-nano multi-level structures on a large area.

[0008] To achieve the above object, the present invention provides a method for preparing a super-hydrophobic surface by ultrasonic rolling nanoparticles, comprising the following steps:

[0009] Pre-treat the alloy surface to make the surface roughness ≤ 0.5 μm, perform ultrasonic cleaning, and dry;

[0010] performing a silanization treatment on the nanoparticles, and bonding the silanized nanoparticles to the alloy surface using an adhesive;

[0011] Nanoparticles were imprinted on the alloy surface using ultrasonic rolling;

[0012] When ultrasonic rolling is used for embossing, the rolling head is radially pressed into the alloy surface, first rolling along the set path one as a whole, and then rolling along the set path two to obtain a superhydrophobic surface.

[0013] Ultrasonic rolling technology used in the present invention is a dynamic rolling technology, i.e., it combines static rolling and ultrasonic impact energy during processing, extrudes and impacts the metal surface, causes larger plastic deformation to occur in the processed surface and introduces residual compressive stress, while the microstructure of the surface is also refined, thereby achieving the purpose of strengthening the surface of metal parts. In addition, due to the self-finishing and good machine tool applicability of ultrasonic rolling, controllable and smooth texture can be manufactured without reprocessing, laying the foundation for the processing of surface texture. Therefore, the present invention utilizes ultrasonic rolling to produce a method for plastic deformation processing micro-texture, proposes a new method for preparing super-hydrophobic surface, the method can simplify the complicated processing process of multi-stage texture, solves the problem of poor mechanical stability of traditional super-hydrophobic surface, realizes the one-step preparation of multi-stage texture, and shows broad engineering application prospects.

[0014] Furthermore, the method for preparing a super-hydrophobic surface by ultrasonic rolling nanoparticles specifically comprises the following steps:

[0015] The alloy surface is ground and polished to a surface roughness (Ra) of ≤0.5μm, and then ultrasonically cleaned. After being taken out and naturally dried, it is fixed on the workbench of the CNC machine tool;

[0016] The nanoparticles are silanized to form strong active groups on the surface of the nanoparticles, and then the silanized nanoparticles are evenly bonded to the alloy surface using an adhesive;

[0017] Install the ultrasonic rolling head on the spindle of the CNC machine tool, start the ultrasonic rolling device, convert the ultrasonic wave into high-frequency mechanical vibration of the rolling head through the ultrasonic generator, and adjust the frequency and amplitude of the ultrasonic wave;

[0018] The CNC machine tool is started, and the rolling head is radially pressed into the alloy surface with a certain static pressure. At the same time, it is rolled along the set path one, so that the rolling head contacts the nanoparticles on the metal surface and rolls relative to each other. The nanoparticles are pressed and embedded using ultrasonic impact energy and static load to form nano-protrusions. Then, the rolling is repeated many times along the set path two. The alloy material is repeatedly squeezed to produce large plastic deformation to form a micron texture, thereby obtaining a super-hydrophobic surface with mechanical stability.

[0019] Furthermore, the alloy includes aluminum alloy, titanium alloy, magnesium alloy or nickel alloy.

[0020] Furthermore, the particle size of the nanoparticles is 200 nm-900 nm, and the nanoparticles of this particle size have good fluidity.

[0021] Furthermore, the nanoparticles include metal ceramic particles, cemented carbide particles and mixed particles thereof.

[0022] Furthermore, the silanization treatment involves immersing the nanoparticles in a silane solution, wherein during the curing process, the silane groups form strong covalent bonds with the metal groups on the particle surface, thereby reducing the surface energy of the nanoparticles. The silane solution is an aqueous solution of trimethylchlorosilane or an anhydrous ethanol solution of n-octyltriethoxysilane.

[0023] Furthermore, the adhesive includes epoxy resin adhesive, phenolic resin adhesive or organic silicone adhesive.

[0024] Furthermore, the process parameters of the ultrasonic rolling are: rolling head diameter 1-6 mm, output frequency 38-42 KHz, amplitude 0-10 μm, and the amplitude is not 0.

[0025] Furthermore, during ultrasonic rolling, both path one and path two adopt a linear reciprocating rolling path.

[0026] Furthermore, during ultrasonic rolling, the static pressure is 200-2000N, the feed speed is 200-2000mm / min, the rolling times are 1-5 times, the groove width is 20-300μm, and the groove depth is 5-80μm.

[0027] Furthermore, the step length of path one is 50-300 μm, and the step length of path two is twice that of path one, so as to embed nanoparticles and process a periodic linear groove micro-texture.

[0028] The present invention utilizes a combination of ultrasonic impact and static load rolling to generate an impact and extrusion effect to cause the alloy material to undergo large-scale elastic-plastic deformation. While preparing a periodic groove micro-texture, nanoparticles are effectively embedded in the texture surface, thereby improving the mechanical stability of the texture and realizing the one-step preparation of a super-hydrophobic functional surface.

[0029] Compared with the prior art, the present invention has the following advantages and technical effects:

[0030] 1. The present invention utilizes the ultrasonic vibration and static pressure of ultrasonic rolling to produce high strain rate plastic deformation, processing micron-scale linear groove microtextures, and at the same time, embedding silanized nanoparticles into the textured surface, thereby realizing the one-step preparation of a multi-level textured surface with superhydrophobic function.

[0031] 2. The present invention significantly improves the mechanical properties and texture strength of the alloy through high-amplitude residual compressive stress and microstructure grain refinement induced by ultrasonic rolling, thereby realizing the integration of material surface strengthening and hydrophobic texture preparation.

[0032] 3. The method of preparing super-hydrophobic surfaces by ultrasonic rolling nanoparticles in the present invention has a simple process and has higher reliability and stability than traditional hydrophobic multi-level textured surfaces, which promotes the widespread application of ultrasonic rolling in the preparation of functional surfaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0034] Figure 1 Schematic diagram of the process for preparing a super-hydrophobic surface by ultrasonically rolling nanoparticles of the present invention, (1) schematic diagram of the morphology of the alloy substrate after surface pretreatment, (2) schematic diagram of the morphology of the alloy substrate with silanized nanoparticles bonded to the surface, (3) schematic diagram of the morphology after rolling along a set path one, (4) schematic diagram of the morphology after rolling along a set path two multiple times; wherein, 1-alloy; 2-adhesive; 3-nanoparticles; 4-rolling head;

[0035] Figure 2 This is a texture morphology image of the super-hydrophobic surface prepared in Example 1 of the present invention;

[0036] Figure 3 Comparison of static contact angles of water droplets on aluminum alloy surfaces before and after processing when ultrasonic rolling nanoparticles are used to prepare super-hydrophobic surfaces in Example 1 of the present invention, (1) before processing, (2) after processing;

[0037] Figure 4 This is a graph showing the average grain size of the aluminum alloy after different surface treatments in Example 1 of the present invention;

[0038] Figure 5 This is a graph showing the average friction coefficient of the aluminum alloy surface after different treatments in Example 1 of the present invention;

[0039] Figure 6 This is a vibration fatigue life diagram of the aluminum alloy surface after different treatments in Example 1 of the present invention;

[0040] Figure 7 Comparison of static contact angles of water droplets on titanium alloy surfaces before and after processing when super-hydrophobic surfaces are prepared by ultrasonic rolling nanoparticles in Example 2 of the present invention, (1) before processing, (2) after processing. DETAILED DESCRIPTION

[0041] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0042] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value within any stated value or stated range, and each smaller range between any other stated value or intermediate value within the stated range, is also encompassed within the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0043] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0044] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be exemplary only.

[0045] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0046] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "axial", "radial", "vertical", "horizontal", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0047] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integral connection; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0048] The schematic diagram of the process for preparing super-hydrophobic surface by ultrasonic rolling nanoparticles of the present invention is as follows: Figure 1 As shown in FIG. 1 (wherein: 1-alloy; 2-adhesive; 3-nanoparticles; 4-rolling head), a method for preparing a super-hydrophobic surface by ultrasonic rolling nanoparticles comprises the following steps:

[0049] The alloy surface is polished in sequence using sandpaper of different particle sizes, wherein the alloy is an aluminum alloy, a titanium alloy, a magnesium alloy or a nickel-based alloy, and then polished using a SiO2 suspension to make Ra ≤ 0.5 μm. Finally, the alloy is ultrasonically cleaned using acetone or alcohol, taken out and naturally dried, and then fixed on a CNC machine tool workbench;

[0050] The nanoparticles are subjected to a silanization treatment on their surfaces. The nanoparticles are selected from metal ceramic powder, cemented carbide powder, and a mixed powder thereof. The powder has a particle size of 200 nm to 900 nm and has good fluidity. The nanoparticles are fully immersed in an aqueous solution of trimethylchlorosilane. During the curing process, the silane groups form a strong covalent bond with the metal groups on the surface of the nanoparticles, thereby reducing the surface energy of the nanoparticles. The silanized nanoparticles are then uniformly bonded to the alloy surface using an adhesive. The adhesive is an epoxy resin adhesive, a phenolic resin adhesive, or an organic silicone adhesive.

[0051] The ultrasonic rolling head is mounted on the spindle of a CNC machine tool, and the ultrasonic rolling device is started. The ultrasonic generator converts the ultrasonic waves into high-frequency mechanical vibrations of the rolling head, and the frequency and amplitude of the ultrasonic waves are adjusted. The ultrasonic rolling process parameters are: rolling head diameter 1-6 mm, output frequency 38-42 kHz, and amplitude 0-10 μm;

[0052] The CNC machine tool is started, and the rolling head is radially pressed into the alloy surface with a certain static pressure, while feeding at a uniform speed along the set path one, so that the rolling head contacts the nanoparticles on the alloy surface and rolls relative to each other, and the nanoparticles are pressed and embedded using ultrasonic impact energy and static load to form nano-protrusions. The process parameters of the CNC machine tool adopt a linear reciprocating rolling path, a static pressure of 200-2000N, a step distance of 50-300μm, a feed speed of 200-2000mm / min, and a rolling number of 1-5 times. Then, the rolling is repeated multiple times along the set path two to form a micron structure. The step distance of the path two is twice that of the path one, so as to process a periodic groove microtexture, the linear groove width is 20-300μm, and the groove depth is 5-80μm, thereby obtaining a super-hydrophobic surface with mechanical stability.

[0053] The present invention utilizes the ultrasonic vibration and static pressure of ultrasonic rolling to generate high strain rate plastic deformation to roll out micron grooves on the alloy surface, inducing the silanized nanoparticles to be pressed and embedded into the textured surface, thereby preparing a multi-level textured surface with super-hydrophobic function. This method can simultaneously achieve one-step preparation of the material surface rolling strengthening and hydrophobic texture, and the strength and stability of the formed hydrophobic texture are significantly improved compared with other preparation methods.

[0054] The present invention will be specifically described below by the following examples.

[0055] Example 1

[0056] (1) First, the surface of 2024 aluminum alloy was polished using sandpaper of 400#, 800#, 1000#, 1500#, and 2000# grit sizes, and then polished with 1.5μm SiO2 suspension to achieve a mirror effect with a surface roughness of ≤0.5μm. Finally, it was ultrasonically cleaned with acetone for 60s, taken out and naturally dried, and then fixed on the workbench of the CNC machine tool;

[0057] (2) Alumina ceramic particles with a particle size of 300-800 nm are selected and immersed in an anhydrous ethanol solution of 4 wt% n-octyltriethoxysilane for 1 hour. The particles are then taken out and placed in an oven at 120°C for drying for 4 hours. During the drying process, the silane groups form a strong covalent bond with the metal groups on the surface of the particles, thereby reducing the surface energy of the nanoparticles to obtain coated modified ceramic micropowders. A layer of epoxy resin adhesive (E-51) is then evenly applied on the surface of the pretreated 2024 aluminum alloy, with a thickness of ≤10 μm. The silanized nanoparticles are then evenly spread on the surface of the aluminum alloy with a scraper, with a powder layer thickness of ≤20 μm, and the nanoparticles are connected to the alloy surface through bonding force;

[0058] (3) Select a rolling head with a diameter of 1 mm, install the ultrasonic rolling head on the spindle of a CNC machine tool, start the ultrasonic rolling device, convert the ultrasonic wave into high-frequency mechanical vibration of the rolling head through the ultrasonic generator, and adjust the frequency of the ultrasonic wave to 40 kHz and the amplitude to 3 μm;

[0059] (4) A static pressure of 600 N, a step size of 50 μm, and a feed speed of 300 mm / min were selected to process the entire aluminum alloy surface using a linear reciprocating rolling path. Powder particles were pressed and embedded to form nano-protrusions. Then, the rolling was repeated three times using a step size of 100 μm to prepare a periodic groove micro-texture. The groove width was 50 μm and the depth was 15 μm. A micro-nano multi-level textured surface with super-hydrophobic function was obtained. The texture morphology is as follows: Figure 2 shown.

[0060] The above-mentioned method of preparing super-hydrophobic surface by ultrasonic rolling nanoparticles was used to prepare a micro-nano multi-level super-hydrophobic texture on the surface of aluminum alloy. After the angle contact measuring instrument test, the contact angle of the prepared aluminum alloy super-hydrophobic functional surface was 159°±0.5°. Figure 3 As shown in the figure, the super-hydrophobic function of the aluminum alloy surface is well achieved. In addition, by comparing the average grain size and friction coefficient under different processes, it is found that the average grain size of ultrasonic rolling is reduced by 29.5% and 33.7% compared with untreated and laser etching, the average friction coefficient is reduced by 27.3% and 29.4%, and the vibration fatigue life is increased by 67.3% and 78.5%, respectively. Figure 4 、 Figure 5 and Figure 6 As shown, the strength of the formed hydrophobic texture is significantly improved compared with other preparation methods, and has good mechanical stability.

[0061] Untreated refers to: 2024 aluminum alloy that has undergone pretreatment, that is, 2024 aluminum alloy that has been ground, polished, and ultrasonically cleaned.

[0062] Laser etching refers to: pre-treated 2024 aluminum alloy is used for laser etching, and the laser etching process parameters are: laser energy 50W, scanning speed 400mm / s, repetition frequency 30kHz, pulse width 100ns, and spacing 50μm.

[0063] Example 2

[0064] (1) First, the surface of TC4 titanium alloy was polished using sandpaper of different particle sizes (400#, 800#, 1000#, 1500#, 2000#), and then polished with 2.5μm SiO2 suspension to achieve a mirror effect with a surface roughness of ≤0.5μm. Finally, it was ultrasonically cleaned with anhydrous ethanol for 60s, taken out and naturally dried, and then fixed on the workbench of the CNC machine tool;

[0065] (2) YG8 cemented carbide particles with a particle size of 400-900 nm were selected and immersed in a 4 wt% n-octyltriethoxysilane anhydrous ethanol solution for 1.5 h. The particles were then taken out and dried in an oven at 150°C for 4 h to obtain coated modified hard particle powders. A layer of phenolic resin adhesive (PF-20) was evenly applied on the pretreated titanium alloy surface with a thickness of ≤10 μm. The silanized nanoparticles were then evenly spread on the alloy surface with a scraper to a powder layer thickness of ≤20 μm to fix the powder on the surface of the alloy to be processed.

[0066] (3) Select a rolling head with a diameter of 3 mm, install the ultrasonic rolling head on the spindle of a CNC machine tool, start the ultrasonic rolling device, convert the ultrasonic wave into high-frequency mechanical vibration of the rolling head through the ultrasonic generator, and adjust the frequency of the ultrasonic wave to 41 kHz and the amplitude to 4 μm;

[0067] (4) A static pressure of 1000 N, a step size of 100 μm, and a feed speed of 200 mm / min were selected, and a linear reciprocating rolling path was used to process the entire titanium alloy surface. Then, the rolling was repeated twice using a step size of 200 μm, with a groove width of 100 μm and a depth of 25 μm, to obtain a micro-nano multi-level textured surface with superhydrophobic function.

[0068] The contact angle of the titanium alloy super-hydrophobic functional surface prepared in this embodiment is 157°±0.5° as measured by an angular contact measuring instrument. Figure 7 As shown, while preparing the multi-level hydrophobic texture, the strength and stability of the texture are enhanced, and the super-hydrophobic function of the titanium alloy surface is better realized.

[0069] Example 3

[0070] (1) First, the surface of AZ31B magnesium alloy was polished using sandpaper of different particle sizes (400#, 800#, 1000#, 1500#, 2000#), and then polished with 2.5μm SiO2 suspension to achieve a mirror effect with a surface roughness of ≤0.5μm. Finally, it was ultrasonically cleaned with anhydrous ethanol for 60s, taken out and naturally dried, and then fixed on the workbench of the CNC machine tool;

[0071] (2) Alumina ceramic particles with a particle size of 300-800 nm were selected and immersed in an anhydrous ethanol solution of 4 wt% n-octyltriethoxysilane for 1 hour. The particles were then taken out and dried in an oven at 150°C for 4 hours to obtain coated modified hard particle micropowders. A layer of organic silicone adhesive (S-3860) was evenly applied on the pretreated titanium alloy surface with a thickness of ≤10 μm. The silanized nanoparticles were then evenly spread on the alloy surface with a scraper to a powder layer thickness of ≤20 μm, so that the powder was fixed on the surface of the alloy to be processed.

[0072] (3) Select a rolling head with a diameter of 6 mm, install the ultrasonic rolling head on the spindle of the CNC machine tool, start the ultrasonic rolling device, convert the ultrasonic wave into high-frequency mechanical vibration of the rolling head through the ultrasonic generator, and adjust the frequency of the ultrasonic wave to 42 kHz and the amplitude to 9 μm;

[0073] (4) A static pressure of 200 N, a step size of 300 μm, and a feed speed of 2000 mm / min were selected, and a linear reciprocating rolling path was used to process the entire titanium alloy surface. Then, the rolling was repeated twice using a step size of 600 μm, with a groove width of 300 μm and a depth of 60 μm, to obtain a micro-nano multi-level textured surface with superhydrophobic function.

[0074] According to the test of the angular contact measuring instrument, the contact angle of the super-hydrophobic functional surface of the magnesium alloy prepared in this embodiment is 154°±0.6°, the average grain size is 44.6 μm, the average friction coefficient is 0.27, and the vibration fatigue life is 342531 times.

[0075] Example 4

[0076] (1) First, the surface of Q345 steel was polished using sandpaper of different particle sizes (400#, 800#, 1000#, 1500#, 2000#), and then polished with 2.0μm SiO2 suspension to achieve a mirror effect with a surface roughness of ≤0.5μm. Finally, it was ultrasonically cleaned with anhydrous ethanol for 60s, taken out and naturally dried, and then fixed on the workbench of the CNC machine tool;

[0077] (2) Alumina ceramic particles with a particle size of 200-600 nm were selected and immersed in a 4 wt% trimethylchlorosilane aqueous solution for 1 h. The particles were then taken out and dried in an oven at 150°C for 4 h to obtain coated modified hard particle micropowders. A layer of epoxy resin adhesive (E-44) was evenly applied on the pretreated titanium alloy surface with a thickness of ≤10 μm. The silanized nanoparticles were then evenly spread on the alloy surface with a scraper to a powder layer thickness of ≤20 μm to fix the powder on the surface of the alloy to be processed.

[0078] (3) Select a rolling head with a diameter of 5 mm, install the ultrasonic rolling head on the spindle of the CNC machine tool, start the ultrasonic rolling device, convert the ultrasonic wave into high-frequency mechanical vibration of the rolling head through the ultrasonic generator, and adjust the frequency of the ultrasonic wave to 38 kHz and the amplitude to 10 μm;

[0079] (4) A static pressure of 1000 N, a step size of 300 μm, and a feed speed of 1000 mm / min were selected, and a linear reciprocating rolling path was used to process the entire titanium alloy surface. Then, the rolling was repeated three times using a step size of 600 μm, with a groove width of 200 μm and a depth of 80 μm, to obtain a micro-nano multi-level textured surface with superhydrophobic function.

[0080] According to the test of the angular contact measuring instrument, the contact angle of the super-hydrophobic functional surface of the nickel alloy prepared in this embodiment is 152°±0.4°, the average grain size is 34.1 μm, and the average friction coefficient is 0.34.

[0081] Example 5

[0082] (1) First, the surface of AZ91D magnesium alloy was polished using sandpaper of different particle sizes (400#, 800#, 1000#, 1500#, 2000#), and then polished with 1.0μm SiO2 suspension to achieve a mirror effect with a surface roughness of ≤0.5μm. Finally, it was ultrasonically cleaned with anhydrous ethanol for 60s, taken out and naturally dried, and then fixed on the workbench of the CNC machine tool;

[0083] (2) Alumina ceramic particles with a particle size of 200-600 nm were selected and immersed in an anhydrous ethanol solution of 4 wt% n-octyltriethoxysilane for 2 h. The particles were then taken out and dried in an oven at 150°C for 4 h to obtain coated modified hard particle micropowders. A layer of epoxy resin adhesive (E-16) was evenly applied on the pretreated titanium alloy surface with a thickness of ≤10 μm. The silanized nanoparticles were then evenly spread on the alloy surface with a scraper to a powder layer thickness of ≤20 μm to fix the powder on the surface of the alloy to be processed.

[0084] (3) Select a rolling head with a diameter of 1 mm, install the ultrasonic rolling head on the spindle of a CNC machine tool, start the ultrasonic rolling device, convert the ultrasonic wave into high-frequency mechanical vibration of the rolling head through the ultrasonic generator, and adjust the frequency of the ultrasonic wave to 40 kHz and the amplitude to 2 μm;

[0085] (4) A static pressure of 800 N, a step size of 200 μm, and a feed speed of 500 mm / min were selected, and a linear reciprocating rolling path was used to process the entire titanium alloy surface. Then, the rolling was repeated 5 times using a step size of 400 μm, with a groove width of 100 μm and a depth of 10 μm, to obtain a micro-nano multi-level textured surface with superhydrophobic function.

[0086] According to the test by an angular contact measuring instrument, the contact angle of the super-hydrophobic functional surface of the magnesium alloy prepared in this embodiment is 153°±0.5°, the average grain size is 31.4 μm, and the average friction coefficient is 0.28.

[0087] Comparative Example 1

[0088] Same as Example 1, except that the particle size of the alumina ceramic particles is 1000nm-1500nm.

[0089] The super-hydrophobic surface of the 2024 aluminum alloy prepared in this comparative example exhibited a contact angle of 120.4°, an average grain size of 61.4 μm, an average friction coefficient of 0.35, and a vibration fatigue life of 1,034,250 cycles. Compared to Example 1, the nanoparticles in this comparative example were too large, and thus the multi-level micro-nanostructure on the magnesium alloy surface was not formed. The contact angle was only 120.4°, indicating a lack of super-hydrophobicity.

[0090] Comparative Example 2

[0091] The same as Example 1, except that the alumina ceramic particles are not immersed in the anhydrous ethanol solution containing 4 wt % n-octyltriethoxysilane.

[0092] The super-hydrophobic surface of the 2024 aluminum alloy prepared in this comparative example exhibited a contact angle of 135.2°, an average grain size of 61.2 μm, an average coefficient of friction of 0.28, and a vibration fatigue life of 1,045,280 cycles. Compared to Example 1, this comparative example lacked silanization of the alumina ceramic particles, resulting in a higher activation energy for the magnesium alloy surface and a contact angle never exceeding 150°, similarly lacking super-hydrophobicity.

[0093] Comparative Example 3

[0094] The same as Example 1, except that the ultrasonic rolling process only adopts a single path rolling.

[0095] The super-hydrophobic surface of the 2024 aluminum alloy prepared in this comparative example exhibited a contact angle of 118.2°, an average grain size of 70.4 μm, an average coefficient of friction of 0.39, and a vibration fatigue life of 952,188 cycles. Compared to Example 1, this comparative example employed only a single rolling path, thus failing to simultaneously produce both micron-scale grooves and nanoscale protrusions. The alloy surface lacked a multi-level texture, and the contact angle never exceeded 150°, similarly lacking super-hydrophobicity.

[0096] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A method for preparing a super-hydrophobic surface by ultrasonic rolling nanoparticles, characterized in that: The steps include: Pre-treat the alloy surface to make the surface roughness ≤ 0.5 μm, perform ultrasonic cleaning, and dry; performing a silanization treatment on the nanoparticles, and bonding the silanized nanoparticles to the alloy surface using an adhesive; Nanoparticles were imprinted on the alloy surface using ultrasonic rolling; When ultrasonic rolling is used for embossing, the rolling head is radially pressed into the alloy surface, first rolling along the set path one as a whole, and then rolling along the set path two to obtain a superhydrophobic surface; The particle size of the nanoparticles is 200nm-900nm; The process parameters of the ultrasonic rolling are: the diameter of the rolling head is 1-6 mm, the output frequency is 38-42 kHz, the amplitude is 0-10 μm, and the amplitude is not 0; During ultrasonic rolling, both path 1 and path 2 adopt a linear reciprocating rolling path; During ultrasonic rolling, the static pressure is 200-2000N, the feed speed is 200-2000mm / min, the number of rolling times is 1-5 times, the groove width is 20-300μm, and the groove depth is 5-80μm.

2. The method for preparing a super-hydrophobic surface by ultrasonic rolling nanoparticles according to claim 1, characterized in that: The alloy includes aluminum alloy, titanium alloy, magnesium alloy or nickel alloy.

3. The method for preparing a super-hydrophobic surface by ultrasonic rolling nanoparticles according to claim 1, characterized in that: The nanoparticles include metal ceramic particles, cemented carbide particles and mixed particles thereof.

4. The method for preparing a super-hydrophobic surface by ultrasonic rolling nanoparticles according to claim 1, characterized in that: The silanization treatment refers to immersing the nanoparticles in a silane solution.

5. The method for preparing a super-hydrophobic surface by ultrasonic rolling nanoparticles according to claim 1, characterized in that: The adhesive includes epoxy resin adhesive, phenolic resin adhesive or organic silicone adhesive.

6. The method for preparing a super-hydrophobic surface by ultrasonic rolling nanoparticles according to claim 1, characterized in that: The step length of path one is 50-300 μm, and the step length of path two is twice the step length of path one.

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