Preparation method and application of organic / ceramic composite spraying powder

Abstract

The invention belongs to the field of seal coating and thermal barrier coating materials, discloses a preparation method and application of organic / ceramic composite spraying powder, and aims to solve the problems that ceramic particles are easy to crush, pore-forming agents are non-uniformly distributed, the pore regulation and control effect is poor, the thickness uniformity of a coating layer is difficult to control and the like in a common powder preparation method. The preparation method comprises the following steps: ultrasonically preparing ceramic powder, an organic solvent and a high polymer electrospray slurry, carrying out electrostatic spray granulation, curing in an inorganic solution to form spherical powder, and finally drying and sintering to obtain the organic / ceramic composite spraying powder. The organic / ceramic composite powder with a hierarchical pore structure is obtained through combination of spray phase conversion and organic matter content and size regulation and control, collaborative design and controllable distribution of nanopores, mesopores and macropores in the spray powder are realized through high-temperature heat treatment, the abradability and high-temperature strength of a coating are improved, the heat conductivity is reduced, and the service life of the coating is prolonged. And thus, the sealing coating / thermal barrier coating with excellent comprehensive performance is obtained.

Description

Technical Field

[0001] This invention belongs to the field of sealing coatings and thermal barrier coating materials, and specifically relates to a method for preparing organic / ceramic composite spray powder and its application. Background Technology

[0002] In advanced thermal energy equipment such as aero-engines and gas turbines, sealing coatings and thermal barrier coatings (TBCs) are key surface engineering materials, widely used in high-temperature aerodynamic components such as high-pressure turbine blades, combustion chambers, guide vanes, and sealing clearance control components. Sealing coatings significantly improve engine thermal efficiency and operational reliability by reducing high-temperature gas leakage, improving aerodynamic sealing, and providing thermal insulation. Thermal barrier coatings, on the other hand, effectively reduce the surface temperature of the base metal, improving the material's heat resistance limit and service life, and are one of the core technologies for achieving high thrust-to-weight ratios and high turbine inlet temperatures.

[0003] Sealing coatings emphasize hermeticity and abrasion resistance, while thermal barrier coatings prioritize thermal insulation and thermal shock resistance. Although their functional focuses differ, they both face similar key challenges: coatings must balance excellent high-temperature mechanical properties with specific functional requirements under harsh conditions of high temperature, high-speed hot airflow, and strong cyclic loading. They must withstand thermal stress and mechanical erosion while meeting the abrasion resistance requirements of the sealing component, and the low thermal conductivity and thermal shock resistance requirements of the thermal barrier coating. However, traditional single-structure ceramic coatings often struggle to achieve a good balance among these properties. For example, while dense ceramic layers can provide high strength and hermeticity, they are brittle and prone to rapid propagation of thermal fatigue cracks. On the other hand, simply introducing higher porosity can reduce thermal conductivity, improve abrasion resistance, or buffer thermal stress, but it significantly reduces the coating's mechanical load-bearing capacity and erosion resistance.

[0004] To address the multifunctional synergistic requirements of sealing coatings and thermal barrier coatings, constructing and precisely controlling a multi-level pore structure—namely, nanopores-mesopores-macropores—is a crucial strategy for enhancing the overall performance of coatings. Nanopores primarily maintain the continuity and strength of the ceramic framework, ensuring hermeticity and basic load-bearing capacity. Mesopores facilitate crack deflection and blunting of crack tips, thereby improving thermal shock resistance and extending thermal cycling life. Macropores, at the micrometer scale, can reduce the coating's elastic modulus, alleviate thermal stress, and provide wearable units in sealing applications, preventing wear on mating components. Through the rational design and distribution of this hierarchical porous structure, a synergistic optimization of high strength and wearability can be achieved in sealing coatings, while a comprehensive balance of low thermal conductivity, thermal shock resistance, and spalling resistance can be achieved in thermal barrier coatings.

[0005] The key to obtaining an ideal hierarchical porous structure lies in the refined design of the powder used for spraying. The powder not only needs appropriate particle size distribution and flowability to adapt to the thermal spraying process, but also requires the pre-introduction of controllable pore-forming units within it, or the provision of precursor conditions for the formation of hierarchical pores. Currently, commonly used powder preparation methods all have significant shortcomings: mechanical mixing methods prepare composite powders by directly ball milling ceramic powder and pore-forming agent particles, but this method easily leads to ceramic particle breakage and uneven distribution of the pore-forming agent, resulting in an unstable porous network in the coating. In-line spraying pore-forming methods directly feed the pore-forming agent and ceramic powder into a high-temperature spray gun. Because the spraying temperature is much higher than the decomposition temperature of the pore-forming agent, a large amount of the pore-forming agent is burned off before deposition, resulting in poor pore control. Coating methods form composite powders by coating the surface of ceramic particles with organic matter or salt-based pore-forming agents, which can partially protect the pore-forming agent from loss during spraying, but it faces problems such as difficulty in uniformly controlling the coating thickness, complex processes, and high costs.

[0006] Whether it's improving the wear resistance-strength coupling performance of sealing coatings or optimizing the synergy between thermal conductivity and thermal shock lifetime of thermal barrier coatings, the rational design and preparation of spray powders are key to breaking through existing technological bottlenecks. By developing novel organic / ceramic composite spray powders with embedded controllable pore-forming units or multiphase microstructures, it is expected that highly controllable multi-level pore networks can be formed in situ within the coating, providing a solid material foundation for achieving synergistic optimization of the structure and performance of high-performance thermal spray functional coatings such as sealing coatings and thermal barrier coatings. Summary of the Invention

[0007] To address the shortcomings of existing spray powder preparation technologies, this invention provides a method for preparing organic / ceramic composite spray powder and its application, suitable for multi-level porous coatings. This method combines spray phase inversion with control of organic content and size to obtain organic / ceramic composite powder with a multi-level porous structure. High-temperature heat treatment enables the synergistic design and controllable distribution of nanopores, mesopores, and macropores in the spray powder, improving the coating's abrasion resistance, high-temperature strength, and reducing thermal conductivity, thereby obtaining a sealing coating / thermal barrier coating with excellent overall performance.

[0008] To achieve the objective of this invention, the technical solution adopted is as follows: A method for preparing an organic / ceramic composite spraying powder includes the following steps: (1) Preparation of electro-spray slurry: ceramic powder, organic solvent and polymer are mixed in proportion, ultrasonically crushed, heated in a mixing device and stirred thoroughly to obtain electro-spray slurry; (2) Electro-spray granulation: The electro-spray slurry is added to the slurry supply device for electrostatic spray granulation, and the electro-spray slurry is atomized into spherical particles by the electro-spray device; (3) Rapid phase transformation and solidification molding of spherical powder: The spherical particles are sprayed into deionized water for rapid molding, and then allowed to stand at room temperature to settle until the organic solvent and inorganic solvent exchange is completed, thus obtaining solidified spherical powder; (4) Drying and high-temperature sintering: The obtained spherical powder is sintered at high temperature to obtain organic / ceramic composite spray powder with different organic contents and pore structures.

[0009] Further, the ceramic powder in step (1) includes one or more composites of ZrO2, Al2O3, TiO2, SiC, BN, graphite, metal, and RE2Zr2O7; The metal is preferably a copper or nickel-based alloy; the RE in RE2Zr2O7 is preferably one or more rare earth elements.

[0010] Further, the organic solvent in step (1) includes one or more of N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide, dimethyl sulfoxide (DMSO), tetrahydrofuran (THF), and triethyl phosphate (TEP).

[0011] Further, the polymers in step (1) include one or more of the following: polysulfones, polyvinyl alcohol (PVA), polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), cellulose derivatives, polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), polyvinyl chloride (PVC), and natural polymers. Among them, polysulfones are preferably polyethersulfone (PES); cellulose derivatives are preferably cellulose acetate (CA); and natural polymers are preferably chitosan.

[0012] Further, in step (1), the mass ratio of ceramic powder, organic solvent and polymer is 1:1 to 30:0.1 to 30.

[0013] Furthermore, the particle size of the ceramic powder in step (1) is 5 nm to 20 μm.

[0014] Furthermore, the solid content of the electro-sprayed grout in step (1) is 10% to 90%.

[0015] Furthermore, in step (1), the power of ultrasonic fragmentation is 80% to 100%, and the fragmentation time is 10 to 30 minutes.

[0016] Furthermore, in step (1), the heating temperature is 10℃~160℃ and the heating time is 1h~36h.

[0017] Furthermore, in step (1), the stirring speed is 100 r / min to 2000 r / min.

[0018] Furthermore, after heating and stirring in step (1) is completed, the oil bath is turned off and stirring continues.

[0019] Furthermore, the slurry supply device in step (2) includes an injection pump, a syringe, and a conduit; The syringe is held by an injection pump and filled with slurry. The tubing is connected to the syringe outlet. The injection rate of the injection pump is preferably 1 mL / min to 30 mL / min.

[0020] Furthermore, the electronic injection device in step (2) includes a DC power supply and an electronic injection needle; The DC power supply provides -40kV to 40kV DC power. The positive terminal is connected to the electric spray needle, and the negative terminal is connected to the receiving device. The distance between the nozzle and the liquid surface of the receiving device is 10cm to 30cm, and the voltage is adjusted to 10kV to 15kV.

[0021] Furthermore, the settling time in step (3) is 10h to 12h.

[0022] Furthermore, the diameter of the spherical powder in step (3) is 1 μm to 500 μm.

[0023] Furthermore, in step (4), the sintering temperature is 100℃~1600℃, the heating rate is 1℃ / min~20℃ / min, and the holding time is 0.5h~100h.

[0024] A method for preparing an organic / ceramic composite spraying powder with added pore-forming agent, comprising the following steps: (1) Preparation of electro-spray slurry: ceramic powder, organic solvent and polymer are mixed in proportion, ultrasonically crushed, heated in a mixing device and stirred thoroughly to obtain electro-spray slurry; The ceramic powder includes one or more composites of ZrO2, Al2O3, TiO2, SiC, BN, graphite, metal, and RE2Zr2O7; the metal is preferably a copper or nickel-based alloy; the RE in RE2Zr2O7 is preferably one or more rare earth elements; the organic solvent includes one or more of N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide, dimethyl sulfoxide (DMSO), tetrahydrofuran (THF), and triethyl phosphate (TEP); the polymer includes polysulfones, polyvinyl alcohol (PVA), polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), cellulose derivatives, and polyvinylpyrrolidone. One or more of the following: ketones (PVP), polyethylene glycol (PEG), polyvinyl chloride (PVC), and natural polymers; polysulfones are preferably polyethersulfone (PES); cellulose derivatives are preferably cellulose acetate (CA); and natural polymers are preferably chitosan; the mass ratio of ceramic powder, organic solvent, and polymer is 1:1–30:0.1–30; the particle size of the ceramic powder is 5 nm–20 μm; the solid content of the electro-sprayed slurry is 10%–90%; the ultrasonic crushing power is 80%–100%, and the crushing time is 10–30 minutes; the heating temperature is 10℃–160℃, and the heating time is 1 h–36 h; and the stirring speed is 100 r / min–2000 r / min.

[0025] (2) Addition of pore-forming agent: Add organic pore-forming agent to the electro-spray slurry and continue to stir evenly; The amount of pore-forming agent added is 0% to 10% of the mass of ceramic powder; the pore-forming agent includes one or more of polypropylene, polyvinyl alcohol, polymethyl methacrylate, polystyrene, and polyethylene glycol organic microspheres; the particle size of the pore-forming agent is 1 μm to 100 μm.

[0026] (3) Electro-spray granulation: The electro-spray slurry with added pore-forming agent is added to the slurry supply device for electrostatic spray granulation, and the electro-spray slurry is atomized into spherical particles by the electro-spray device; The slurry supply device includes an injection pump, a syringe, and a conduit; the syringe is preferably held by the injection pump and filled with slurry, and the conduit is connected to the syringe outlet; the injection rate of the injection pump is preferably 1 mL / min to 30 mL / min; the electro-spraying device includes a DC power supply and an electro-spraying needle; the DC power supply provides -40 kV to 40 kV DC power, the positive terminal is connected to the electro-spraying needle, the negative terminal is connected to the receiving device, the nozzle is 10 cm to 30 cm away from the liquid surface of the receiving device, and the voltage adjustment is preferably 10 kV to 15 kV.

[0027] (4) Rapid phase transformation and solidification of spherical powder: The spherical particles are sprayed into deionized water for rapid solidification, and then allowed to stand at room temperature to settle until the organic solvent and inorganic solvent exchange is completed, thus obtaining solidified spherical powder; The preferred settling time is 10h to 12h; the preferred diameter of the spherical powder is 1μm to 500μm.

[0028] (5) Drying and high-temperature sintering: The obtained spherical powder is pre-fired to remove organic matter, and then calcined at high temperature to obtain organic / ceramic composite spray powder with different organic matter content and pore structure; The sintering temperature is 100℃~1600℃, the heating rate is 1℃ / min~20℃ / min, and the holding time is 0.5h~100h.

[0029] The organic / ceramic composite spray powder prepared by the method of preparing organic / ceramic composite spray powder with added pore-forming agent provided by the present invention can be applied to sealing coating materials and thermal barrier coating materials.

[0030] The above technical solution has the following beneficial effects: This invention provides a high-efficiency, low-energy-consumption method for preparing organic / ceramic composite spray powder that can be used for the preparation of multi-level porous structure coatings. This method significantly improves the sphericity, porosity control capability and production efficiency of the powder through material formulation and process combination, overcoming the bottlenecks of high energy consumption, single pore structure and slow molding speed of traditional processes, and obtaining organic / ceramic composite spray powder products with excellent comprehensive performance. Its core advantages are reflected in the following aspects: (1) The electrostatic atomization-room temperature phase conversion molding process is adopted; the electrostatic atomization and room temperature phase conversion process replaces the traditional high temperature spray drying, and the ceramic body can be rapidly molded under normal temperature conditions, which greatly reduces energy consumption. At the same time, high-quality powder with sphericity >95% is obtained. By precisely controlling the slurry viscosity and atomization parameters, the particle size can be precisely controlled to meet the needs of different application scenarios; (2) Through the directional interdiffusion of organic solvent and inorganic solvent, through-hole channels are formed in the ceramic body. At the same time, the size and content of macropores (organic matter) are customized by combining the size and content control of organic particles. After high-temperature calcination, powders with varying organic content and hierarchical pore size distributions can be obtained, exhibiting good strength and flowability. This method features a simple process flow, low energy consumption, controllable pore size, uniform organic distribution, and high yield, effectively overcoming the problems of single pore structure, high energy consumption, and slow molding speed in existing ceramic powder technologies. It can be widely applied in high-value-added fields requiring precise control of pore structure, such as sealing coatings, thermal barrier coatings, catalyst supports, high-temperature filtration, and biomedical applications. Compared with existing technologies, this invention has significant advantages such as fast molding speed, wide pore design range, and low overall energy consumption, demonstrating broad industrialization prospects and significant technical and economic value. Attached Figure Description

[0031] Figure 1 This is a scanning electron microscope (SEM) image of the cross-section of the organic / ceramic composite spray powder with added pore-forming agent according to the present invention. Figure 2 This is a scanning electron microscope (SEM) image of the organic / ceramic composite sprayed powder in this invention. Figure 3 This is a scanning electron microscope (SEM) image of the cross-section of the organic / ceramic composite spray powder without the addition of a pore-forming agent in this invention. Detailed Implementation

[0032] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0033] Example 1 The method for preparing organic / ceramic composite spraying powder provided by this invention includes the following specific steps: (1) Preparation of electro-sprayed slurry: Take ceramic powder: organic solvent: polymer = 1:1~30:0.1~30 by mass ratio. Mix the ceramic powder with a portion of the organic solvent, and reserve the other portion of the organic solvent for rinsing the beaker into the conical flask. Disperse the mixed solution twice in an ultrasonic cell disruptor for 10 min~30 min, with the amplitude transformer penetrating the liquid more than 1 cm. Add the polymer to the conical flask first, ensuring that the polymer does not stick to the wall. Add the ultrasonically dispersed mixed solution, add the reserved other portion of the organic solvent, and stir to ensure that the polymer at the bottom does not stick to the flask wall as much as possible. Fix the conical flask on an iron stand and place it in an oil bath. Heat the temperature to 10℃~160℃ and stir at 100r / min~2000r / min for 1h~36h to obtain the electro-sprayed slurry. (2) Electrostatic spray granulation: Prepare an electrostatic spray granulation device. Use a 100mL syringe and add 70mL to 80mL of electrostatic spray slurry. Fix the syringe to the injection pump, and lock the bottom and the push part. Connect the end of the syringe to the tubing with a Luer connector. Connect the other side of the tubing to the needle. Set the injection rate to 1mL / min to 30mL / min. Fix the needle to the support. Connect the positive electrode to the needle and the negative electrode to the iron plate. Add pure water to the iron plate. Adjust the distance between the needle and the liquid surface to 10cm to 30cm. After checking the power supply, start the power supply and the injection pump. Adjust the voltage to 10kV to 15kV. It is necessary to ensure that the bottom of the iron plate is dry and water-free. During the granulation process, it is necessary to use an insulating material to stir continuously to prevent the generated oil film from affecting the electric field distribution and to disperse the spherical particles to prevent agglomeration. The electrostatic spray slurry is atomized into spherical particles through the electrostatic spray device. (3) Rapid phase transformation solidification molding of spherical powder: Spray spherical particles into deionized water for rapid molding, let the mixture stand at room temperature for 10h-12h to precipitate, then remove the supernatant, ultrasonically clean the remaining solution, filter it with filter cloth, and air dry it naturally for 12h to obtain solidified spherical powder. (4) Drying and high-temperature sintering: The obtained spherical powder is pre-fired to remove organic matter, and then calcined at 1300℃ for 10h to obtain ceramic spray powder with multi-level pore structure.

[0034] Before electrostatic spray granulation, the particle size of any powder must be determined to be in the submicron or a few micrometer range; otherwise, the solution will cause pipe blockage and subsequent sintering of the spherical structure will collapse.

[0035] Example 2 The method for preparing organic / ceramic composite spraying powder with added pore-forming agent provided by the present invention includes the following specific steps: (1) Preparation of electro-sprayed slurry: Take ceramic powder: organic solvent: polymer = 1:1~30:0.1~30 by mass ratio. Mix the ceramic powder with a portion of the organic solvent, and reserve the other portion of the organic solvent for rinsing the beaker into the conical flask. Disperse the mixed solution twice in an ultrasonic cell disruptor for 10 min~30 min, with the amplitude transformer penetrating the liquid more than 1 cm. Add the polymer to the conical flask first, ensuring that the polymer does not stick to the wall. Add the ultrasonically dispersed mixed solution, add the reserved other portion of the organic solvent, and stir to ensure that the polymer at the bottom does not stick to the flask wall as much as possible. Fix the conical flask on an iron stand and place it in an oil bath. Heat the temperature to 10℃~160℃ and stir at 100r / min~2000r / min for 1h~36h to obtain the electro-sprayed slurry. (2) Addition of pore-forming agent: After the electro-sprayed slurry cools, add 0% to 10% pore-forming agent and stir evenly; (3) Electrostatic spray granulation: Prepare an electrostatic spray granulation device, use a 100mL syringe, add 70mL to 80mL of slurry, fix the syringe on the injection pump, lock the bottom and the push part, connect the end of the syringe with a tubing with a Luer connector, connect the other side of the tubing to the needle, set the injection rate to 1mL / min to 30mL / min; fix the needle on the bracket, connect the positive electrode to the needle, connect the negative electrode to the iron plate, add pure water to the iron plate, adjust the distance between the needle and the liquid surface to 10cm to 30cm, check the power supply and start the power supply and injection pump, adjust the voltage to 10kV to 15kV, it is necessary to ensure that the bottom of the iron plate is dry and waterless, during the granulation process, it is necessary to use an insulating material to stir continuously to prevent the generated oil film from affecting the electric field distribution and to disperse the spherical particles to prevent agglomeration; the electrostatic spray slurry is atomized into spherical particles through the electrostatic spray device.

[0036] (4) Rapid phase transformation solidification molding of spherical powder: Spray spherical particles into deionized water for rapid molding, let the mixture stand at room temperature for 10h-12h to settle, then remove the supernatant, ultrasonically clean the remaining solution, filter with filter cloth, and air dry for 12h to obtain solidified spherical powder. (5) Drying and high-temperature sintering: The obtained spherical powder is pre-fired at 100℃ to remove organic matter, and then calcined at 1300℃ for 8 hours and held for 90 hours to obtain organic / ceramic composite spray powder with different organic matter content and pore structure.

[0037] Before electrostatic spray granulation, the particle size of any powder must be determined to be in the submicron or a few micrometer range; otherwise, the solution will cause pipe blockage and subsequent sintering of the spherical structure will collapse.

[0038] Example 3 The preparation method of organic / ceramic composite spraying powder with added pore-forming agent is as follows: (1) Weigh 30g of 8YSZ powder, 300g of N-methyl-2-pyrrolidone (NMP), and 30g of polyethersulfone (PES). Mix the 8YSZ powder and N-methyl-2-pyrrolidone evenly in a beaker, and then ultrasonically disperse them twice for 10min. The amplitude transformer is inserted 1cm into the liquid. Add PES to the conical flask in advance to prevent the high viscosity after mixing from causing some slurry to adhere to the beaker. Finally, add the ultrasonically dispersed mixture of 8YSZ powder and N-methyl-2-pyrrolidone to the conical flask. Place the conical flask containing the slurry in an oil bath and clamp it. Adjust the rotation speed to 1000r / min and the heating temperature to 70℃. Stir the slurry for 6h. Turn off the oil bath heating pot and cool the slurry to room temperature to obtain the electro-sprayed slurry. (2) Weigh 3g (10% of 8YSZ mass) of polypropylene granules and add them to the electro-spray slurry. Continue stirring at room temperature for 6 hours to mix evenly. (3) Add the electro-sprayed slurry into the syringe, connect the syringe to the tubing with the Luer connector, connect the nozzle to the other side of the tubing, fix the syringe to the injection pump, fix the needle to the bracket, and then assemble the electrostatic spray granulation equipment. Connect the positive terminal of the high voltage DC power supply to the nozzle and the negative terminal to the iron plate. Add 3000mL of deionized water to the plate to ensure that the bottom of the iron plate is dry. Adjust the height of the needle from the liquid surface to 15cm. Adjust the voltage of the positive and negative terminals of the power supply to 15kV, set the injection pump injection rate to 3mL / min, start the equipment, and after the injection is stable, the spray at the needle is a stable umbrella shape. Use an insulating object to stir the liquid surface to disperse the oil film generated on the liquid surface and separate the generated spherical particles to prevent all particles from gathering at the bottom of the nozzle. After the slurry electro-spraying is completed, atomized spherical particles are obtained. (4) Transfer the spherical particles and liquid in the iron pan to a beaker and let them settle for 12 hours. Allow the powder in the precipitate suspension to stand for a while. Pour out the clear liquid after precipitation, and place a portion of the clear liquid and powder in a 100% power ultrasonic cleaner for ultrasonic cleaning for 10 minutes. Filter the ultrasonically cleaned suspension using a collection tank with a filter cloth. Let the obtained powder air dry at room temperature for 12 hours. (5) After drying, the spherical powder is sieved through 50 mesh and 400 mesh, and the middle part is retained. This is the organic / ceramic composite spraying powder with a pore-forming agent content of 10%. The microstructure of the powder cross-section is as follows: Figure 1 As shown, the surface of the powder is as follows Figure 2 As shown.

[0039] Example 4 The preparation method of organic / ceramic composite spraying powder includes the following steps: (1) Weigh 50g of ZrO2 powder, 150g of N-methyl-2-pyrrolidone (NMP) and 10g of polyvinyl alcohol (PVA). Mix ZrO2 powder and N-methyl-2-pyrrolidone (NMP) evenly in a beaker, and ultrasonically disperse for 5min twice. Insert the amplitude transformer into the liquid 1cm. Add PVA to the conical flask in advance to prevent the high viscosity after mixing from causing some slurry to adhere to the beaker. Finally, add the ultrasonically dispersed mixture to the flask. Place the conical flask containing the slurry in an oil bath and clamp it. Adjust the rotation speed to 200r / min and the heating temperature to 80℃. Stir the slurry for 20h. Turn off the oil bath heating pot and continue stirring at room temperature for 6h.

[0040] (2) Add the electro-sprayed slurry to the syringe, connect the syringe to the conduit with a Luer connector, connect the nozzle to the other side of the conduit, fix the syringe to the injection pump, fix the needle to the bracket, and then assemble the electrostatic spray granulation equipment. Connect the positive terminal of the high voltage DC power supply to the nozzle and the negative terminal to the iron plate. Add 3000mL of pure water to the plate to ensure that the bottom of the iron plate is dry. Adjust the height of the needle from the liquid surface to 10cm. Adjust the voltage of the positive and negative terminals of the power supply to 10kV, set the injection pump injection rate to 3mL / min, start the equipment, and after the injection is stable, the spray at the needle is a stable umbrella shape. Use an insulating object to stir the liquid surface to disperse the oil film generated on the liquid surface and separate the generated spherical particles to prevent all the particles from gathering at the bottom of the nozzle. After the slurry electro-spraying is completed, atomized spherical particles are obtained.

[0041] (3) Transfer the spherical particles and liquid in the iron pan to a beaker and precipitate for 10 hours to fully precipitate the powder in the suspension; pour out the clear liquid after precipitation, and place a portion of the clear liquid and powder in an ultrasonic cleaner with 100% power for ultrasonic cleaning for 30 minutes. Use a collection tank with filter cloth to filter the suspension after ultrasonic cleaning, and air dry the obtained powder at room temperature for 10 hours.

[0042] (4) The dried spherical powder is sieved through a 50-mesh sieve to remove large particles, obtaining an organic / ceramic composite spray powder. The microstructure of the powder is as follows: Figure 3 As shown.

[0043] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for preparing an organic / ceramic composite spraying powder, characterized in that, Including the following steps: (1) Preparation of electro-spray slurry: ceramic powder, organic solvent and polymer are mixed in proportion, ultrasonically crushed, heated in a mixing device and stirred thoroughly to obtain electro-spray slurry; (2) Electro-spray granulation: The electro-spray slurry is added to the slurry supply device for electrostatic spray granulation, and the electro-spray slurry is atomized into spherical particles by the electro-spray device; (3) Rapid phase transformation and solidification molding of spherical powder: The spherical particles are sprayed into deionized water for rapid molding, and then allowed to stand at room temperature to settle until the organic solvent and inorganic solvent exchange is completed, thus obtaining solidified spherical powder; (4) Drying and high-temperature sintering: The obtained spherical powder is sintered at high temperature to obtain organic / ceramic composite spray powder with different organic contents and pore structures; The ceramic powder includes one or more of ZrO2, Al2O3, TiO2, SiC, BN, graphite, metal, and RE2Zr2O7; The organic solvent includes one or more of N-methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, tetrahydrofuran, and triethyl phosphate; The polymers include one or more of the following: polysulfones, polyvinyl alcohol, polyvinylidene fluoride, polyacrylonitrile, cellulose derivatives, polyvinylpyrrolidone, polyethylene glycol, polyvinyl chloride, and natural polymers. The mass ratio of the ceramic powder, organic solvent, and polymer is 1:1 to 30:0.1 to 30.

2. The method for preparing organic / ceramic composite spraying powder according to claim 1, characterized in that: The metal is a copper or nickel-based alloy; RE in RE2Zr2O7 is one or more rare earth elements; the polysulfone is polyethersulfone; the cellulose derivative is cellulose acetate; and the natural polymer is chitosan.

3. The method for preparing organic / ceramic composite spraying powder according to claim 1, characterized in that: The particle size of the ceramic powder in step (1) is 5nm to 20μm; the solid content of the electro-sprayed slurry is 10% to 90%; the power of the ultrasonic crushing is 80% to 100%, and the crushing time is 10 to 30 minutes; the heating temperature is 10℃ to 160℃, and the heating time is 1h to 36h; the stirring speed is 100r / min to 2000r / min; after the heating and stirring are completed, the oil bath is turned off and stirring continues.

4. The method for preparing organic / ceramic composite spraying powder according to claim 1, characterized in that: The slurry supply device in step (2) includes an injection pump, a syringe, and a conduit; the syringe is held by the injection pump and filled with slurry, and the conduit is connected to the syringe outlet; the injection rate of the injection pump is 1 mL / min to 30 mL / min.

5. The method for preparing organic / ceramic composite spraying powder according to claim 1, characterized in that: The electro-injection device in step (2) includes a DC power supply and an electro-injection needle; the DC power supply provides -40kV to 40kV DC power, the positive terminal is connected to the electro-injection needle, the negative terminal is connected to the receiving device, the nozzle is 10cm to 30cm away from the liquid surface of the receiving device, and the voltage is adjusted to 10kV to 15kV.

6. The method for preparing organic / ceramic composite spraying powder according to claim 1, characterized in that: The settling time in step (3) is 10h to 12h; the diameter of the spherical powder is 1μm to 500μm.

7. The method for preparing organic / ceramic composite spraying powder according to claim 1, characterized in that: The sintering temperature in step (4) is 100℃~1600℃, the heating rate is 1℃ / min~20℃ / min, and the holding time is 0.5h~100h.

8. A method for preparing an organic / ceramic composite spraying powder as described in any one of claims 1-7, characterized in that: In step (2), a pore-forming agent is added to the electro-sprayed slurry; the amount of the pore-forming agent added is 0% to 10% of the mass of the ceramic powder; the pore-forming agent includes one or more of polypropylene, polyvinyl alcohol, polymethyl methacrylate, polystyrene, and polyethylene glycol; the particle size of the pore-forming agent is 1 μm to 100 μm.

9. The application of a method for preparing organic / ceramic composite spraying powder as described in any one of claims 1-7, characterized in that: The organic / ceramic composite spray powder prepared by the method is used in sealing coating materials and thermal barrier coating materials.

10. The application of a method for preparing organic / ceramic composite spray powder as described in claim 8, characterized in that: The organic / ceramic composite spray powder prepared by the method is used in sealing coating materials and thermal barrier coating materials.

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