Laser processing method for hydrophilic-hydrophobic composite surface of ceramic material

Abstract

The application discloses a laser processing method for hydrophilic and hydrophobic composite surfaces of ceramic materials, which adopts differentiated processing by using ultra-short pulse laser: a close joint strategy is adopted for the hydrophilic region, and primary micro-grooves are formed by one-step high-energy and low-speed processing; a sparse joint strategy is adopted for the hydrophobic region, micro-grooves are formed by high-energy and low-speed processing first, and then nano-particle deposition is induced by low-energy and high-speed processing, and after cleaning and selective gas phase modification, a hydrophilic and hydrophobic composite surface is obtained. The application can quantitatively control the contact angle and realize super-hydrophilic and super-hydrophobic high contrast; the structure is integrated with the base body, and the bonding force is high; complex pattern processing is completed by the same clamping; the application is suitable for various oxides, non-oxide ceramics and additive manufacturing surfaces, and can be widely applied to the fields of micro-fluid control, biological medicine, thermal energy devices and the like.

Description

Technical Field

[0001] This invention belongs to the field of ceramic material surface modification technology, specifically relating to a laser processing method for a hydrophilic-hydrophobic composite surface of ceramic materials. Background Technology

[0002] Structural ceramics such as alumina, silicon nitride, zirconium oxide, and silicon carbide, with their superior properties including high hardness, high strength, high elastic modulus, low creep, high temperature resistance, and corrosion resistance, have been widely used in high-end technology fields such as aerospace hot-end components, semiconductor packaging, artificial joints, and dental restorations. As precision devices evolve towards extreme operating conditions, high reliability, and long lifespans, the demand for surface functionalization of ceramic components is becoming increasingly urgent, and surface wettability control has become a key technology for expanding their application boundaries. During service, the surface wettability of materials directly affects their heat transfer efficiency, self-cleaning, and friction and wear properties. For example, constructing a superhydrophilic layer on the inner wall of the film cooling vents in aero-engines can significantly reduce the pressure drop of the cooling airflow; introducing superhydrophobic microtextures on the ball joint surface of artificial joints can reduce synovial fluid adhesion and the generation of wear particles, thereby extending the implant's lifespan; and achieving hydrophilic-hydrophobic patterning on the surface of MEMS packaging ceramic substrates allows for precise solder spreading without flux, improving packaging reliability. In practical applications, a single hydrophilic or hydrophobic surface is no longer sufficient to meet the requirements of multifunctional coupling of devices under complex working conditions. Achieving a controllable spatial distribution of hydrophilic and hydrophobic regions on the same ceramic substrate, i.e., a hydrophilic-hydrophobic composite surface, has become an important means to improve the overall performance and reliability of devices.

[0003] Currently, the control of surface wettability of ceramic materials mainly employs techniques such as coating, chemical vapor deposition (CVD), electrochemical methods, and laser etching. Regarding coating methods, Chinese patent CN116102933B discloses a superhydrophobic ceramic substrate coating and its preparation method. This method achieves superhydrophobicity by preparing a composite coating of fluorinated modified acrylic resin and nano-silica on the ceramic substrate surface. However, this method relies on physical adhesion between the coating and the ceramic substrate, resulting in low bonding strength. It is prone to cracking and peeling under high-temperature thermal cycling and can only achieve overall hydrophobicity, failing to create high-precision hydrophilic-hydrophobic partitioning patterns. Regarding CVD methods, Chinese patent CN116060274B discloses a method for preparing self-healing hydrophobic nanofilms using plasma-enhanced chemical vapor deposition (PECVD). This method deposits a fluorinated siloxane hydrophobic nanofilm on the ceramic surface. While it can obtain a uniform hydrophobic surface, the equipment is expensive, the deposition process requires a vacuum environment and is time-consuming, and it cannot complete the preparation of hydrophilic-hydrophobic composite patterns in one step, requiring additional masking or etching steps. In terms of electrochemical methods, Chinese patent CN112701345A discloses a superhydrophobic material that can conduct lithium ions and its preparation method. The hydrophobicity is achieved by constructing micro-nano structures on the surface of conductive ceramics through electrochemical deposition. However, this method is only applicable to conductive ceramic substrates and is not suitable for widely used non-conductive oxide ceramics (such as alumina and zirconium oxide) and non-oxide ceramics (such as silicon nitride), resulting in a very narrow range of substrate applications.

[0004] Laser etching, as a maskless and non-contact processing technique, has been widely used in recent years for controlling the wettability of ceramic surfaces. Chinese patent CN114833442A discloses a method for preparing a biomimetic superhydrophobic / ultra-low adhesion surface for sanitary ware ceramics. This method involves etching a micro / nano composite structure on the ceramic surface using a femtosecond laser, followed by modification with fluorosilane to obtain a superhydrophobic surface. However, this method can only prepare surfaces with a single wettability and cannot achieve a controllable spatial distribution of hydrophilic and hydrophobic regions on the same substrate. Chinese patent CN115138221A discloses a method for preparing a Janus ceramic film. This method first modifies the ceramic film to be hydrophilic, and then coats it with a hydrophobic coating using a mask to obtain a composite surface with one side hydrophilic and the other hydrophobic. However, this method relies on masking processes and organic hydrophobic coatings, and still suffers from low film-substrate bonding strength and poor thermal stability. Furthermore, it can only achieve a single-sided overall wettability difference and cannot prepare complex microscale hydrophilic and hydrophobic patterns arbitrarily distributed within a plane.

[0005] In summary, existing methods for preparing hydrophilic-hydrophobic composite ceramic surfaces generally suffer from the following technical problems: ceramic materials have strong atomic bonds and strong chemical inertness, making it difficult to achieve high spatial resolution and one-time molding of different wetting regions using traditional wet chemical modification; coating methods are cumbersome and have low film-substrate bonding strength, making them prone to peeling off during thermal cycling and difficult to achieve controllable wetting regions; chemical vapor deposition methods are expensive and cannot complete hydrophilic-hydrophobic patterning in one step; electrochemical methods are only applicable to conductive ceramics and have a narrow substrate range; traditional laser etching methods often focus on a single wettability (such as superhydrophilic or superhydrophobic), failing to achieve controllable spatial distribution of hydrophilic-hydrophobic regions and thus failing to meet the high reliability and long lifespan requirements of ceramic devices for surface functionalization under extreme operating conditions. Summary of the Invention

[0006] In view of this, the present invention provides a laser processing method for a hydrophilic-hydrophobic composite surface of ceramic materials. The technical solution of the present invention is as follows: A laser processing method for a hydrophilic-hydrophobic composite surface of ceramic material, characterized by comprising the following steps: S1. Polish the surface of the ceramic material to be processed; S2. Divide the surface of the ceramic material into hydrophilic and hydrophobic regions; S3. Processing is performed by focusing an ultrashort pulse laser onto the surface of ceramic materials: S31. A close-overlapping strategy is adopted for the hydrophilic area, and high energy density and low scanning speed are used to process it to form a primary microgroove. S32. For the hydrophobic area, a loose overlapping strategy is adopted, and two steps are performed sequentially: Step 1: Processing with high energy density and low scanning speed to form primary microgrooves; Step 2: Processing with low energy density and high scanning speed, so that the sputtering material generated during the processing is deposited into nanoparticles in the trench area; S4. Place the processed sample in an organic solvent for ultrasonic cleaning, and then place it in a drying oven to dry. S5. Place the sample into a vacuum container, cover the surface of the hydrophilic region with a protective film, and perform vapor phase modification on the hydrophobic region to obtain a hydrophilic-hydrophobic composite surface.

[0007] In this invention, the polishing process in step S1 eliminates the interference of the original surface roughness on the laser energy distribution, ensuring the consistency and precision of microstructure processing and providing a uniform substrate for subsequent wettability control; the region division in step S2 predefines functional zones, providing a positioning reference for subsequent differentiated laser processing and enabling the designability of hydrophilic and hydrophobic patterns of arbitrary shapes.

[0008] Step S31, hydrophilic region processing: High-energy-density lasers induce nonlinear ablation of the ceramic surface, forming a continuous microgroove structure. Simultaneously, a large number of oxygen vacancies and polar groups such as hydroxyl groups are induced, significantly increasing surface energy. A close-application strategy connects the microgrooves, enhancing capillary action and collectively achieving superhydrophilicity. Step S32, hydrophobic region processing: The first step, high-energy, low-speed processing, is similar to the hydrophilic region, forming a primary microgroove substrate. The second step, low-energy, high-speed processing, uses insufficient laser energy to generate new ablation, only allowing the molten sputtering from the first step to redeposit on the top of the grooves, forming 50-200 nm nanoprotrusions, constructing a dual rough structure of "microgrooves + nanoparticles." A loose-application strategy isolates the microstructures, facilitating air trapping and forming an air cushion, laying the structural foundation for subsequent superhydrophobicity. Nanoparticles further reduce the actual contact area between droplets and the surface, significantly reducing the roll-off angle and achieving ultra-low adhesion superhydrophobicity.

[0009] Step S4, cleaning and drying, removes loose debris, molten spatter, and surface contaminants generated during laser processing to prevent them from affecting the uniformity and adhesion of subsequent vapor phase modification. Step S5, selective modification, uses a protective film to shield the hydrophilic region, allowing low-surface-energy fluorosilane molecules to be grafted onto the hydrophobic region. This reduces the surface energy of the hydrophobic region without changing its chemical state, ultimately forming a composite surface with a significant contrast between hydrophilic and hydrophobic properties.

[0010] This invention utilizes the triple effects of ultrafast laser ablation, chemical modification, and nano-deposition to construct different micro / nano structures and surface chemical states on the same ceramic substrate through differentiated processing strategies, thereby achieving a controllable spatial distribution of hydrophilic and hydrophobic regions.

[0011] Furthermore, the ceramic material is an oxide ceramic or a non-oxide ceramic; the oxide ceramic includes at least one of alumina and zirconium oxide, and the non-oxide ceramic includes at least one of silicon nitride and silicon carbide. In this invention, material processing is achieved based on the nonlinear effects of multiphoton absorption and plasma emission using ultrafast lasers, independent of the material's conductivity; therefore, it is applicable to both insulating oxide and non-oxide ceramics.

[0012] Furthermore, in step S1, the surface roughness of the polished ceramic material is less than 0.2 μm. In this invention, when the surface roughness is greater than 0.2 μm, the unevenness of the original surface will cause inconsistent laser focusing depth and uneven energy distribution, resulting in a deviation of more than 10% in the depth and width of the processed microgrooves, making it impossible to achieve stable wettability control.

[0013] Furthermore, the wavelength of the ultrashort pulse laser is 515-1030nm, the pulse width is 300fs-10ps, the repetition frequency is 100kHz-2MHz, and the focused spot diameter is 10-30µm.

[0014] In this invention, by setting an appropriate wavelength, the ceramic material exhibits high laser absorption (greater than 60%) in this wavelength band, resulting in high energy utilization and effective material ablation. Furthermore, the optical system for this wavelength band is mature. The equipment cost is controllable; by setting the pulse width, the heat-affected zone is made less than 1μm, which can avoid defects such as cracking and deformation of ceramics due to thermal stress and achieve cold processing; at the same time, it can induce strong nonlinear effects and generate abundant surface chemically active groups; by setting the repetition frequency, processing efficiency and processing quality are balanced. The processing efficiency is too low below 100kHz, while the thermal accumulation effect is obvious above 2MHz, which can easily lead to microstructure melting and deformation; by setting the focusing spot diameter, the minimum width of the microgroove is determined. This range can meet the accuracy requirements of most microfluidic and thermal energy devices, while ensuring processing efficiency.

[0015] Furthermore, in step S31, the high energy density is 5-10 J / cm², and the low scan speed is 50-200 mm / s; in step S32, the low energy density is 0.3-2 J / cm², and the high scan speed is 300-1000 mm / s.

[0016] In this invention, by setting a high energy density—higher than the ablation threshold of ceramics (approximately 3-4 J / cm²)—it can effectively remove material and form microgrooves with a depth of 5-20 μm. Below 5 J / cm², effective ablation cannot be achieved, while above 10 J / cm², the heat-affected zone is too large, and the microstructure edges are rough. By setting a low scanning speed, sufficient laser energy input per unit area is ensured to form microgrooves with a suitable aspect ratio. Too low a speed will lead to overburning, while too high a speed will result in insufficient trench depth. By setting a low energy density—below the ablation threshold of ceramics—no new material removal will occur; only the molten sputtered material generated in the first step can be redeposited. Below 0.3 J / cm², the sputtered material cannot be melted and deposited, while above 2 J / cm², the already formed microgrooves will be ablated again. By setting a high scanning speed, the deposition amount and size of nanoparticles are controlled. Too low a speed will cause nanoparticles to agglomerate and become too large; too high a speed will result in insufficient deposition, failing to form an effective micro-nano composite structure.

[0017] Furthermore, the diameter of the nanoparticles deposited in step S32 is 50-200 nm; the overlap rate of the close overlap strategy is 50-80%, and the overlap rate of the sparse overlap strategy is 10-30%.

[0018] In this invention, by setting the diameter of the nanoparticles, the nanoparticles can form an ideal micro-nano composite rough structure with micron-grooves. Combined with low surface energy modification, superhydrophobicity with a contact angle greater than 160° can be achieved. Nanoparticles smaller than 50 nm are prone to wear and shedding, while those larger than 200 nm will result in excessively high surface roughness, making droplets easy to adhere. By setting a close overlap rate, adjacent laser scanning trajectories overlap by 50-80%, forming a continuous and dense microgroove network, enhancing capillary action and improving hydrophilicity. Below 50%, the microgrooves are discontinuous, and capillary action is weakened. Above 80%, the processing efficiency is greatly reduced, and surface overheating is likely to occur. By setting a sparse overlap rate, adjacent laser scanning trajectories overlap by only 10-30%, forming isolated microstructure units, which is conducive to trapping air and forming a Cassie-Baxter state, improving hydrophobicity. Below 10%, the microstructure distribution is too sparse, and the hydrophobicity is unstable. Above 30%, the microstructure is too dense and cannot effectively trap air.

[0019] Furthermore, in step S4, the organic solvent is anhydrous ethanol or acetone, and the ultrasonic cleaning time is 10-30 min.

[0020] Furthermore, in step S5, the medium for gas-phase modification is fluorosilane, the modification temperature is 50-90℃, and the modification time is 10-30 min.

[0021] In this invention, fluorosilane molecules contain low surface energy -CF3 groups. After grafting onto the ceramic surface, the surface energy can be reduced from approximately 70 mJ / m² to below approximately 10 mJ / m², making it a commonly used modifier for achieving superhydrophobicity. Furthermore, vapor-phase modification can uniformly cover all surfaces of the micro / nano structure, including the bottom of trenches and the surface of nanoparticles. By setting the modification temperature, the volatilization of fluorosilane is accelerated, increasing its concentration in the vacuum container, while simultaneously promoting the chemical reaction between fluorosilane molecules and hydroxyl groups on the ceramic surface, forming strong covalent bonds. Below 50°C, the reaction rate is too slow; above 90°C, the decomposition of fluorosilane intensifies, reducing the modification effect. By setting the modification time, a complete monolayer of fluorosilane molecules is ensured on the hydrophobic region surface. Below 10 minutes, grafting is insufficient, and the contact angle does not meet requirements; above 30 minutes, the grafting amount no longer increases, resulting in material waste.

[0022] Furthermore, in the obtained hydrophilic-hydrophobic composite surface, the contact angle of the hydrophilic region is less than 20°, and the contact angle of the hydrophobic region is greater than 120°; furthermore, the hydrophilic region is a superhydrophilic region with a contact angle less than 5°, and the hydrophobic region is a superhydrophobic region with a contact angle greater than 160°. The contact angle is a core indicator for measuring surface wettability. By adjusting laser processing parameters (energy density, scanning speed, overlap rate), the surface microstructure and chemical state can be quantitatively controlled, thereby achieving precise control of the contact angle. In this invention, the hydrophilic-hydrophobic contact angle contrast is greater than 140°, far exceeding the level of existing technologies, and can meet the requirements for multifunctional coupling of devices under extreme operating conditions.

[0023] Furthermore, in step S3, during laser processing of the hydrophobic region, in-situ silicone oil pyrolysis or carbon doping treatment is used to simultaneously reduce the surface energy of the hydrophobic region, thus omitting the fluorosilane vapor phase modification step in step S5. In this invention, laser processing and surface chemical modification are completed simultaneously, omitting the subsequent vapor phase modification step and simplifying the process flow; at the same time, the use of fluorides is avoided, making it more environmentally friendly.

[0024] In this invention, in-situ silicone oil pyrolysis can be achieved by introducing dimethyl silicone oil vapor at a flow rate of 5-20 sccm into the processing cavity. The high energy of the laser causes the silicone oil molecules to pyrolyze, producing carbon-containing low surface energy substances that are directly deposited on the surface of the micro-nano structure in the hydrophobic region. In-situ carbon doping can be achieved by laser-induced carbon plasma generation on a graphite target or by pre-coating the ceramic surface with carbon sources such as graphite powder and phenolic resin, allowing carbon elements to penetrate into the ceramic surface lattice to form a carbon-rich layer and reduce the surface energy.

[0025] The innovation of this invention lies in the organic combination of the multiple effects of ultrafast lasers with a differentiated processing strategy, solving the technical challenge of achieving high adhesion, high precision, and designable hydrophilic-phobic composite surfaces on the same ceramic substrate using existing technologies. Existing technologies either use uniform parameters to process surfaces with a single wettability or employ an indirect method combining coating and laser etching to prepare composite surfaces. This invention proposes a differentiated processing flow using a one-step / two-step method to address the different wettability requirements of hydrophilic and hydrophobic regions. It achieves precise design of surface microstructures by quantitatively controlling the laser scanning overlap rate, thereby quantitatively controlling the contact angle. This invention enables one-time molding of hydrophilic and hydrophobic regions without the need for a mask, allows for independent pattern design, and achieves a resolution comparable to the laser spot size, overcoming the shortcomings of low patterning precision and cumbersome procedures in traditional processes.

[0026] Existing laser processing technologies utilize only the ablation effect of lasers to form single micron-sized structures. This invention, however, achieves material ablation through a first step of high-energy, low-speed processing, forming a micron-groove substrate. A second step of low-energy, high-speed processing then induces the redeposition of the sputtered material generated in the first step, forming nanoprotrusions in situ, thus constructing a micro / nano composite structure integrating microgrooves and nanoparticles. This structure is integrally metallurgically bonded to the ceramic substrate, with a bonding strength far exceeding that of traditional coating methods. This completely solves the problems of easy coating peeling and poor thermal stability, meeting the service requirements under extreme operating conditions.

[0027] This invention achieves simultaneous control of structural and chemical modification, solving the problem of traditional methods where structural and chemical modification are performed step-by-step and the process is cumbersome. During laser processing, oxygen vacancies and polar groups are simultaneously induced on the surface, achieving chemical modification of the hydrophilic region without additional treatment; the hydrophobic region achieves superhydrophobicity through the synergistic effect of micro / nano composite structures and low surface energy modification. Optional in-situ silicone oil pyrolysis or carbon doping processes can simultaneously reduce surface energy while laser processing the hydrophobic region, omitting the subsequent fluorosilane vapor-phase modification step. This not only further simplifies the process but also avoids the use of fluorides, making it more environmentally friendly.

[0028] This invention is applicable to all oxide and non-oxide ceramics, including non-conductive ceramics, overcoming the limitation of traditional electrochemical methods that are only applicable to conductive ceramic substrates. It can complete the processing of hydrophilic and hydrophobic patterns of arbitrary shapes and sizes in a single clamping operation, meeting the manufacturing requirements of complex macro-micro-nano multi-level wetting patterns. Simultaneously, it exhibits excellent compatibility with complex ceramic surfaces manufactured using additive manufacturing, enabling integrated manufacturing. This invention can be widely applied in cutting-edge fields such as aerospace hot-end components, semiconductor packaging, artificial joints and dental restorations, and microfluidic chips, possessing extremely high practical value. The beneficial effects of this invention are as follows:

[0029] 1. By adjusting process parameters such as laser energy density, scanning speed and overlap rate, the periodic structure can be precisely controlled, thereby quantitatively designing the contact angle and realizing the hydrophilic and hydrophobic zone differences; 2. The oxygen vacancies and polar groups on the surface of the laser-induced material can instantly increase the surface energy, achieving superhydrophilicity; if supplemented by in-situ silicone oil pyrolysis or carbon doping, the surface energy can be reduced simultaneously, achieving superhydrophobicity, thus omitting the subsequent fluorination step. 3. Selective processing of hydrophilic and hydrophobic regions can be completed in the same clamping, meeting the requirements of complex macro-micro-nano multi-level wetting patterns, and providing an integrated manufacturing means for ceramic microfluidics, biochips and thermal management devices; 4. It is applicable to both oxide and non-oxide ceramics, and has good compatibility with the surfaces of complex additive manufacturing materials. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of laser processing of the hydrophilic-hydrophobic composite surface of the ceramic material of the present invention; Figure 2 This is a schematic diagram showing the distribution of hydrophilic and hydrophobic regions in the ceramic material of this invention; Figure 3 This is a schematic diagram showing the distribution of hydrophilic and hydrophobic regions in the ceramic material of this invention; Figure 4 A schematic diagram of a hydrophilic-hydrophobic composite surface of ceramic materials; The numbers in the figure are explained as follows: 1-Ceramic, 2-Closely overlapped processing area, 3-Lowly overlapped processing area, 4-Nanoparticle covered area, 5-Vacuum phase treatment area, 6-Hydrophobic area, 7-Hydrophilic area, 8-Liquid hydrophilic state, 9-Liquid hydrophobic state. Detailed Implementation

[0031] The technical solutions will now be clearly and completely described in conjunction with embodiments of the present invention. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. Example 1

[0032] A laser processing method for a hydrophilic-hydrophobic composite surface of ceramic material includes the following steps: S1. Polish the surface of the alumina ceramic 1 to be processed so that the surface roughness after polishing is 0.15μm; S2. Divide the surface of alumina ceramic 1 into a hydrophilic region 7 and a hydrophobic region 6; S3. Processing is performed by focusing an ultrashort pulse laser onto the surface of alumina ceramic 1. The laser parameters are: wavelength 1030nm, pulse width 10ps, repetition frequency 1MHz, and focused spot diameter 20μm. S31. A close overlap strategy is adopted for the hydrophilic region 7. The region is processed with an energy density of 8J / cm², a scanning speed of 100mm / s, and an overlap rate of 60% to form a primary microgroove and obtain the close overlap processing region 2. S32. For the hydrophobic area 6, a loose overlapping strategy is adopted, and two steps are performed sequentially: Step 1: Process with an energy density of 8J / cm², a scanning speed of 100mm / s, and an overlap rate of 25% to form primary microgrooves and obtain a loosely overlapped processing area 3; Step 2: The process is carried out with an energy density of 1.5 J / cm², a scanning speed of 500 mm / s, and an overlap rate of 25%. The sputtering generated during the process is deposited into nanoparticles in the trench area to obtain nanoparticle-covered area 4. The average diameter of the nanoparticles deposited in the hydrophobic area 6 is about 120 nm, as characterized by scanning electron microscopy (SEM). S4. Place the processed alumina ceramic 1 in anhydrous ethanol for ultrasonic cleaning for 20 minutes, and then dry it in a drying oven at 60℃. S5. Place the alumina ceramic 1 into a vacuum container, cover the surface of the hydrophilic region 7 with a high-temperature resistant PET protective film, and perform 1H,1H,2H,2H-perfluorodecyltriethoxysilane vapor phase modification on the hydrophobic region 6. The modification temperature is 70℃ and the modification time is 20min to obtain the vapor phase treated region 5.

[0033] Under the conditions of room temperature 25℃ and relative humidity 50%, the alumina ceramic composite surface 1 was obtained by using a contact angle measuring instrument to obtain the hydrophilic region 7 exhibiting a liquid hydrophilic state 8 (contact angle 7°) and the hydrophobic region 6 exhibiting a liquid hydrophobic state 9 (contact angle 165°). Example 2

[0034] A laser processing method for a hydrophilic-hydrophobic composite surface of ceramic material includes the following steps: S1. Polish the surface of the zirconia ceramic 1 to be processed so that the surface roughness after polishing is 0.1μm; S2. Divide the surface of zirconia ceramic 1 into a hydrophilic region 7 and a hydrophobic region 6; S3. Processing is performed by focusing an ultrashort pulse laser onto the surface of zirconia ceramic 1. The laser parameters are: wavelength 515nm, pulse width 300fs, repetition frequency 200kHz, and focused spot diameter 15μm. S31. A close overlap strategy is adopted for the hydrophilic region 7. The region is processed with an energy density of 6J / cm², a scanning speed of 80mm / s, and an overlap rate of 75% to form a primary microgroove and obtain the close overlap processing region 2. S32. For the hydrophobic area 6, a loose overlapping strategy is adopted, and two steps are performed sequentially: Step 1: Process with an energy density of 8J / cm², a scanning speed of 80mm / s, and an overlap rate of 15% to form primary microgrooves and obtain a loosely overlapped processing area 3; Step 2: The process is carried out with an energy density of 0.7 J / cm², a scanning speed of 750 mm / s, and an overlap rate of 20%. The sputtering generated during the process is deposited into nanoparticles in the trench area to obtain nanoparticle-covered area 4. The average diameter of the nanoparticles deposited in the hydrophobic area 6 is about 80 nm, as characterized by scanning electron microscopy (SEM). S4. Place the processed zirconia ceramic 1 in anhydrous ethanol for ultrasonic cleaning for 15 minutes, and then dry it in a drying oven at 60℃. S5. Place the zirconia ceramic 1 into a vacuum container, cover the surface of the hydrophilic region 7 with a high-temperature resistant PET protective film, and perform 1H,1H,2H,2H-perfluorodecyltriethoxysilane vapor phase modification on the hydrophobic region 6. The modification temperature is 60℃ and the modification time is 15min to obtain the vapor phase treated region 5.

[0035] Under the conditions of room temperature 25℃ and relative humidity 50%, a contact angle measuring instrument was used to test the zirconia ceramic 1 composite surface, which showed that the hydrophilic region 7 exhibited a liquid hydrophilic state 8 (contact angle 5°) and the hydrophobic region 6 exhibited a liquid hydrophobic state 9 (contact angle 170°). Example 3

[0036] A laser processing method for a hydrophilic-hydrophobic composite surface of ceramic material includes the following steps: S1. Polish the surface of the silicon nitride ceramic 1 to be processed so that the surface roughness after polishing is 0.1μm; S2. Divide the surface of silicon nitride ceramic 1 into a hydrophilic region 7 and a hydrophobic region 6; S3. Processing is performed by focusing an ultrashort pulse laser onto the surface of silicon nitride ceramic 1. The laser parameters are: wavelength 1030nm, pulse width 800fs, repetition frequency 500kHz, and focused spot diameter 20μm. S31. A close overlap strategy is adopted for the hydrophilic region 7. The region is processed with an energy density of 7J / cm², a scanning speed of 150mm / s, and an overlap rate of 60% to form a primary microgroove and obtain the close overlap processing region 2. S32. For the hydrophobic area 6, a loose overlapping strategy is adopted, and two steps are performed sequentially: Step 1: Process with an energy density of 7J / cm², a scanning speed of 150mm / s, and an overlap rate of 25% to form primary microgrooves and obtain a loosely overlapped processing area 3; Step 2: The process is carried out with an energy density of 1.5 J / cm², a scanning speed of 500 mm / s, and an overlap rate of 10%. The sputtering generated during the process is deposited into nanoparticles in the trench area to obtain nanoparticle-covered area 4. The average diameter of the nanoparticles deposited in the hydrophobic area 6 is about 150 nm, as characterized by scanning electron microscopy (SEM). S4. Place the processed silicon nitride ceramic 1 in acetone for ultrasonic cleaning for 15 minutes, and then dry it in a 60℃ drying oven. S5. Place silicon nitride ceramic 1 into a vacuum container, cover the surface of hydrophilic region 7 with a high-temperature resistant PET protective film, and perform 1H,1H,2H,2H-perfluorodecyltriethoxysilane vapor phase modification on hydrophobic region 6. The modification temperature is 70℃ and the modification time is 25min to obtain vapor phase treated region 5.

[0037] Under the conditions of room temperature 25℃ and relative humidity 50%, a contact angle measuring instrument was used to test and obtain a composite surface of silicon nitride ceramic 1 in which the hydrophilic region 7 exhibits a liquid hydrophilic state 8 (contact angle 3°) and the hydrophobic region 6 exhibits a liquid hydrophobic state 9 (contact angle 160°). Example 4

[0038] A laser processing method for a hydrophilic-hydrophobic composite surface of ceramic material includes the following steps: S1. Polish the surface of the silicon carbide ceramic 1 to be processed so that the surface roughness after polishing is 0.18μm; S2. Divide the surface of silicon carbide ceramic 1 into a hydrophilic region 7 and a hydrophobic region 6; S3. Processing is performed by focusing an ultrashort pulse laser onto the surface of silicon carbide ceramic 1. The laser parameters are: wavelength 1030nm, pulse width 1ps, repetition frequency 800kHz, and focused spot diameter 25μm. S31. A close overlap strategy is adopted for the hydrophilic region 7. The region is processed with an energy density of 7J / cm², a scanning speed of 120mm / s, and an overlap rate of 50% to form a primary microgroove and obtain the close overlap processing region 2. S32. For the hydrophobic area 6, a loose overlapping strategy is adopted, and two steps are performed sequentially: Step 1: Process with an energy density of 7J / cm², a scanning speed of 120mm / s, and an overlap rate of 30% to form primary microgrooves and obtain a loosely overlapped processing area 3; Step 2: Processing with an energy density of 2 J / cm², a scanning speed of 600 mm / s, and an overlap rate of 30% to deposit nanoparticles in the trench area from the sputtered material generated during processing, resulting in nanoparticle-covered region 4; characterization by scanning electron microscopy (SEM) shows that the average diameter of the nanoparticles deposited in the hydrophobic region 6 is approximately 180 nm. S4. Place the processed silicon carbide ceramic 1 in anhydrous ethanol for ultrasonic cleaning for 25 minutes, and then dry it in a drying oven at 60℃. S5. Place silicon carbide ceramic 1 into a vacuum container, cover the surface of hydrophilic region 7 with a high-temperature resistant PET protective film, and perform 1H,1H,2H,2H-perfluorodecyltriethoxysilane vapor phase modification on hydrophobic region 6. The modification temperature is 75℃ and the modification time is 25min to obtain vapor phase treated region 5.

[0039] Under the conditions of room temperature 25℃ and relative humidity 50%, a contact angle measuring instrument was used to test the composite surface of silicon carbide ceramic 1, in which the hydrophilic region 7 exhibits a liquid hydrophilic state 8 (contact angle 6°) and the hydrophobic region 6 exhibits a liquid hydrophobic state 9 (contact angle 162°). Example 5

[0040] A laser processing method for a hydrophilic-hydrophobic composite surface of ceramic material includes the following steps: S1. Polish the surface of the alumina ceramic 1 to be processed so that the surface roughness after polishing is 0.12μm; S2. Divide the surface of alumina ceramic 1 into a hydrophilic region 7 and a hydrophobic region 6; S3. A short pulse laser is used to focus on the surface of alumina ceramic 1 for processing. The laser parameters are: wavelength 1030nm, pulse width 5ps, repetition frequency 1.5MHz, and focused spot diameter 20μm. S31. A close overlap strategy is adopted for the hydrophilic region 7. The region is processed with an energy density of 5J / cm², a scanning speed of 50mm / s, and an overlap rate of 70% to form a primary microgroove and obtain the close overlap processed region 2. S32. For the hydrophobic area 6, a loose overlapping strategy is adopted, and two steps are performed sequentially: Step 1: Process with an energy density of 5J / cm², a scanning speed of 50mm / s, and an overlap rate of 20% to form primary microgrooves and obtain a loosely overlapped processing area 3; Step 2: The process is carried out with an energy density of 1.2 J / cm², a scanning speed of 300 mm / s, and an overlap rate of 20%. The sputtering generated during the process is deposited into nanoparticles in the trench area to obtain nanoparticle-covered area 4. The average diameter of the nanoparticles deposited in the hydrophobic area 6 is about 100 nm, as characterized by scanning electron microscopy (SEM). S4. Place the processed alumina ceramic 1 in acetone for ultrasonic cleaning for 30 minutes, and then dry it in a 60℃ drying oven. S5. Place the alumina ceramic 1 into a vacuum container, cover the surface of the hydrophilic region 7 with a high-temperature resistant PET protective film, and perform 1H,1H,2H,2H-perfluorodecyltriethoxysilane vapor phase modification on the hydrophobic region 6. The modification temperature is 65℃ and the modification time is 20min to obtain the vapor phase treated region 5.

[0041] Under the conditions of room temperature 25℃ and relative humidity 50%, the alumina ceramic composite surface 1 was obtained by using a contact angle measuring instrument to obtain a liquid hydrophilic state 8 (contact angle 8°) in the hydrophilic region 7 and a liquid hydrophobic state 9 (contact angle 163°) in the hydrophobic region 6. Example 6

[0042] A laser processing method for a hydrophilic-hydrophobic composite surface of ceramic material includes the following steps: S1. Polish the surface of the zirconia ceramic 1 to be processed so that the surface roughness after polishing is 0.08μm; S2. Divide the surface of zirconia ceramic 1 into a hydrophilic region 7 and a hydrophobic region 6; S3. Processing is performed by focusing an ultrashort pulse laser onto the surface of zirconia ceramic 1. The laser parameters are: wavelength 515nm, pulse width 1ps, repetition frequency 2MHz, and focused spot diameter 15μm. S31. A close overlap strategy is adopted for the hydrophilic region 7. The region is processed with an energy density of 10J / cm², a scanning speed of 200mm / s, and an overlap rate of 80% to form a primary microgroove and obtain the close overlap processing region 2. S32. For the hydrophobic area 6, a loose overlapping strategy is adopted, and two steps are performed sequentially: Step 1: Process with an energy density of 10 J / cm², a scanning speed of 200 mm / s, and an overlap rate of 15% to form primary microgrooves and obtain a loosely overlapped processing area 3; Step 2: The process is carried out with an energy density of 0.3 J / cm², a scanning speed of 1000 mm / s, and an overlap rate of 15%. The sputtering generated during the process is deposited into nanoparticles in the trench area to obtain nanoparticle-covered area 4. The average diameter of the nanoparticles deposited in the hydrophobic area 6 is about 60 nm, as characterized by scanning electron microscopy (SEM). S4. Place the processed zirconia ceramic 1 in anhydrous ethanol for ultrasonic cleaning for 10 minutes, and then dry it in a drying oven at 60℃. S5. Place the zirconia ceramic 1 into a vacuum container, cover the surface of the hydrophilic region 7 with a high-temperature resistant PET protective film, and perform 1H,1H,2H,2H-perfluorodecyltriethoxysilane vapor phase modification on the hydrophobic region 6. The modification temperature is 80℃ and the modification time is 15min to obtain the vapor phase treated region 5.

[0043] Under the conditions of room temperature 25℃ and relative humidity 50%, a contact angle measuring instrument was used to test the zirconia ceramic 1 composite surface, which showed that the hydrophilic region 7 exhibited a liquid hydrophilic state 8 (contact angle 4°) and the hydrophobic region 6 exhibited a liquid hydrophobic state 9 (contact angle 168°). Example 7

[0044] A laser processing method for a hydrophilic-hydrophobic composite surface of ceramic material includes the following steps: S1. Polish the surface of the silicon nitride ceramic 1 to be processed so that the surface roughness after polishing is 0.1μm; S2. Divide the surface of silicon nitride ceramic 1 into a hydrophilic region 7 and a hydrophobic region 6; S3. A short pulse laser is focused onto the surface of silicon nitride ceramic 1 for processing. The laser parameters are: wavelength 1030 nm, pulse width 800 fs, repetition frequency 500 kHz, and focused spot diameter 20 μm. During processing, dimethyl silicone oil vapor with a flow rate of 10 sccm is continuously introduced into the hydrophobic region 6 to achieve in-situ silicone oil pyrolysis modification. S31. A close overlap strategy is adopted for the hydrophilic region 7. The region is processed with an energy density of 7J / cm², a scanning speed of 150mm / s, and an overlap rate of 60% to form a primary microgroove and obtain the close overlap processing region 2. S32. For the hydrophobic area 6, a loose overlapping strategy is adopted, and two steps are performed sequentially: Step 1: Process with an energy density of 7J / cm², a scanning speed of 150mm / s, and an overlap rate of 25% to form primary microgrooves and obtain a loosely overlapped processing area 3; Step 2: The process is carried out with an energy density of 1.5 J / cm², a scanning speed of 500 mm / s, and an overlap rate of 25%. The sputtering generated during the process is deposited into nanoparticles in the trench area to obtain nanoparticle-covered area 4. The average diameter of the nanoparticles deposited in the hydrophobic area 6 is about 140 nm, as characterized by scanning electron microscopy (SEM). S4. Place the processed silicon nitride ceramic 1 in acetone for ultrasonic cleaning for 15 minutes, and then dry it in a 60℃ drying oven. No subsequent fluorosilane vapor phase modification is required.

[0045] Under the conditions of room temperature 25℃ and relative humidity 50%, a contact angle measuring instrument was used to test and obtain a composite surface of silicon nitride ceramic 1 in which the hydrophilic region 7 exhibits a liquid hydrophilic state 8 (contact angle 3°) and the hydrophobic region 6 exhibits a liquid hydrophobic state 9 (contact angle 161°).

[0046] Comparative Example 1 A laser processing method for the surface of a ceramic material includes the following steps: S1. Polish the surface of the alumina ceramic 1 to be processed so that the surface roughness after polishing is 0.15μm; S2. Do not divide the surface of ceramic 1 into regions; S3. Use an ultrashort pulse laser to focus on the entire surface of alumina ceramic 1, and perform one-step processing using uniform parameters: Laser parameters: wavelength 1030nm, pulse width 10ps, repetition frequency 1MHz, focused spot diameter 20μm; Processing parameters: energy density 8J / cm², scanning speed 100mm / s, overlap rate 60%; S4. Place the processed alumina ceramic 1 in anhydrous ethanol for ultrasonic cleaning for 20 minutes, and then place it in a drying oven to dry. S5. Place the alumina ceramic 1 into a vacuum container and perform fluorosilane vapor phase modification on the entire surface to obtain a single hydrophobic surface with a full-surface contact angle of 112°.

[0047] Comparative Example 2 A laser processing method for a hydrophilic-hydrophobic composite surface of ceramic material includes the following steps: S1. Polish the surface of the alumina ceramic 1 to be processed so that the surface roughness after polishing is 0.15μm; S2. Divide the surface of alumina ceramic 1 into a hydrophilic region 7 and a hydrophobic region 6; S3. Processing is performed by focusing an ultrashort pulse laser onto the surface of alumina ceramic 1: S31. A close overlap strategy is adopted for the hydrophilic region 7. The region is processed with an energy density of 8J / cm², a scanning speed of 100mm / s, and an overlap rate of 60% to form a primary microgroove and obtain the close overlap processing region 2. S32. For the hydrophobic area 6, a loose overlapping strategy is adopted, requiring only one step of processing: The primary microgrooves were formed by processing with an energy density of 8 J / cm², a scanning speed of 100 mm / s, and an overlap rate of 25%, resulting in a loosely overlapped processing area 3. The second step of nanoparticle deposition was omitted. S4. Place the processed alumina ceramic 1 in anhydrous ethanol for ultrasonic cleaning for 20 minutes, and then place it in a drying oven to dry. S5. Place the alumina ceramic 1 into a vacuum container, cover the surface of the hydrophilic region 7 with a protective film, and perform vapor phase modification on the hydrophobic region 6 to obtain a ceramic composite surface with a contact angle of 7° for the hydrophilic region 7 and a contact angle of 128° for the hydrophobic region 6.

[0048] Comparative Example 3 A method for preparing a hydrophilic-hydrophobic composite surface of ceramic material (existing technology method) includes the following steps: S1. Substrate pretreatment: Polish the surface of alumina ceramic 1 to a surface roughness of 0.15μm, ultrasonically clean it with anhydrous ethanol for 10min, and dry it for later use. S2. Preparation of hydrophobic coating: Prepare a 1wt% solution of 1H,1H,2H,2H-perfluorodecyltriethoxysilane in anhydrous ethanol and stir until homogeneous; completely immerse the polished alumina ceramic 1 in the above solution for 30 min; remove and place in a 120℃ drying oven for 1 h to cure, and obtain a uniform hydrophobic coating with an initial full-surface contact angle of 135°. S3. Nanosecond laser etching of hydrophilic region: A fiber nanosecond laser is used to etch a designated area to form a hydrophilic region 7. Laser core parameters: wavelength 1064nm, pulse width 100ns, repetition frequency 30kHz, focused spot diameter 50μm; Processing parameters: energy density 1.2 J / cm², scanning speed 300 mm / s, scanning overlap rate 60%, number of scans 1; Processing method: The hydrophilic and hydrophobic pattern design is exactly the same as that in Example 1; S4. Post-processing: The etched sample was ultrasonically cleaned in anhydrous ethanol for 10 minutes to remove loose coating debris and carbonization products from the surface. After drying, a ceramic composite surface with a contact angle of 32° for hydrophilic region 7 and a contact angle of 132° for hydrophobic region 6 was obtained.

[0049] Comparative Example 4 A method for preparing a superhydrophobic surface of a ceramic material (existing technology method) includes the following steps: S1. Substrate pretreatment: The surface of conductive silicon carbide ceramic 1 is polished to a surface roughness of 0.15μm, ultrasonically cleaned with anhydrous ethanol for 10min, and dried for later use. S2. Electrochemical anodizing: Conductive silicon carbide ceramic 1 is used as the anode and platinum sheet is used as the cathode. Anodizing is carried out in 0.5 mol / L oxalic acid solution at a voltage of 20 V for 30 min. S3. Hydrophobic modification: After washing with deionized water, the sample was immersed in 1wt% 1H,1H,2H,2H-perfluorodecyltriethoxysilane ethanol solution for 2h, and then dried to obtain a single superhydrophobic surface with a contact angle of 142°. Experimental effect test

[0050] All tests were conducted under strictly standardized conditions: room temperature 23-25℃, relative humidity 50±5%, using the same batch of testing equipment, and performing three parallel tests with the average value taken. The methods and standards for each test item are as follows: 1. Surface wettability test: A contact angle measuring instrument was used, and the droplet volume was 5 μL; the roll-off angle test was conducted using the tilt table method, with a droplet volume of 10 μL, and the tilt angle at which the droplet began to roll was recorded. 2. Membrane-substrate bonding strength test: The cross-cut test was used with a 6-blade cross-cutting tool and a 1mm spacing between the cuts. After the test, 3M 600 tape was applied and then peeled off vertically. The surface peeling was observed and the grade was evaluated. 3. Thermal cycling stability test: A high and low temperature alternating test chamber was used. The test conditions were: -40℃~150℃, heating and cooling rate of 5℃ / min, holding temperature for 30min per cycle, and a total of 50 cycles were performed. After the cycle, the contact angle of the hydrophobic area was measured and the contact angle retention rate was calculated. 4. Friction and wear stability test: A reciprocating friction and wear testing machine was used. The test conditions were: load 5N, friction pair GCr15 steel balls (diameter 6mm), sliding speed 10mm / s, sliding stroke 10mm, and reciprocating cycles 1000 times; after the test, the contact angle of the hydrophobic area was measured. 5. Verification Test of Applicability to Multiple Ceramic Materials: Using the same process parameters as in Example 1, alumina, zirconium oxide, silicon nitride, and silicon carbide ceramics were processed respectively. The contact angles of their hydrophilic and hydrophobic regions were tested, and the results were compared with those obtained by electrochemical and coating methods. Specifically, the above test methods followed existing national or industry standards, and the results are as follows: Table 1 Surface wettability and hydrophobicity / hydrophobicity contrast test

[0051] Table 2 Cross-cut bonding strength test

[0052] Table 3 Thermal Cycling Stability Test

[0053] Table 4 Friction and Wear Stability Test

[0054] Table 5. Verification Tests for the Suitability of Multiple Ceramic Materials (Processing Method of Example 1)

[0055] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0056] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. It should be noted that any technical features not described in detail in this invention can be implemented using any existing technology.

Claims

1. A laser processing method for a hydrophilic-hydrophobic composite surface of ceramic materials, characterized in that, Includes the following steps: S1. Polish the surface of the ceramic material to be processed; S2. Divide the surface of the ceramic material into hydrophilic and hydrophobic regions; S3. Processing is performed by focusing an ultrashort pulse laser onto the surface of ceramic materials: S31. A close-overlapping strategy is adopted for the hydrophilic area, and high energy density and low scanning speed are used to process it to form a primary microgroove. S32. For the hydrophobic area, a loose overlapping strategy is adopted, and two steps are performed sequentially: Step 1: Processing with high energy density and low scanning speed to form primary microgrooves; Step 2: Processing with low energy density and high scanning speed, so that the sputtering material generated during the processing is deposited into nanoparticles in the trench area; S4. Place the processed sample in an organic solvent for ultrasonic cleaning, and then place it in a drying oven to dry. S5. Place the sample into a vacuum container, cover the surface of the hydrophilic region with a protective film, and perform vapor phase modification on the hydrophobic region to obtain a hydrophilic-hydrophobic composite surface.

2. The laser processing method according to claim 1, characterized in that, The ceramic material is an oxide ceramic or a non-oxide ceramic; the oxide ceramic includes at least one of alumina and zirconium oxide, and the non-oxide ceramic includes at least one of silicon nitride and silicon carbide.

3. The laser processing method according to claim 1, characterized in that, In step S1, the surface roughness of the polished ceramic material is less than 0.2 μm.

4. The laser processing method according to claim 1, characterized in that, The ultrashort pulse laser has a wavelength of 515-1030nm, a pulse width of 300fs-10ps, a repetition frequency of 100kHz-2MHz, and a focused spot diameter of 10-30µm.

5. The laser processing method according to claim 1, characterized in that, In step S31, the high energy density is 5-10 J / cm² and the low scan speed is 50-200 mm / s; in step S32, the low energy density is 0.3-2 J / cm² and the high scan speed is 300-1000 mm / s.

6. The laser processing method according to claim 1, characterized in that, The diameter of the nanoparticles deposited in step S32 is 50-200 nm; the overlap rate of the close overlap strategy is 50-80%, and the overlap rate of the sparse overlap strategy is 10-30%.

7. The laser processing method according to claim 1, characterized in that, In step S4, the organic solvent is anhydrous ethanol or acetone, and the ultrasonic cleaning time is 10-30 min.

8. The laser processing method according to claim 1, characterized in that, In step S5, the medium for gas-phase modification is fluorosilane, the modification temperature is 50-90℃, and the modification time is 10-30 min.

9. The laser processing method according to claim 1, characterized in that, In the obtained hydrophilic-hydrophobic composite surface, the contact angle of the hydrophilic region is less than 20° and the contact angle of the hydrophobic region is greater than 120°; further, the hydrophilic region is a superhydrophilic region with a contact angle of less than 5°, and the hydrophobic region is a superhydrophobic region with a contact angle of greater than 160°.

10. The laser processing method according to claim 1, characterized in that, In step S3, when laser processing the hydrophobic region, in-situ silicone oil pyrolysis or carbon doping treatment is used to simultaneously reduce the surface energy of the hydrophobic region, thus omitting the fluorosilane vapor phase modification process in step S5.

Images