Gas assisted coaxial electrostatic spray device and method for preparing aluminum-based energetic composite material using the same

Abstract

This invention discloses a gas-assisted coaxial electrostatic spraying device and a method for preparing aluminum-based energetic composite materials. The device includes a gas-liquid flow transport unit, an electrostatic generator, and a receiving plate. The gas-liquid flow transport unit includes an outer tube and an inner tube coaxially fitted together, forming an airflow cavity between the outer and inner tubes. The inner tube includes a liquid-passing pipe and a nozzle coaxially connected together, with a liquid spraying port at the front end of the nozzle. The airflow cavity is closed at the rear end and has an air outlet at the front end corresponding to the liquid spraying port. An air inlet is provided on the side wall of the outer tube, which is connected to a gas transport device via a pipe. The gas transport device is used to deliver gas into the airflow cavity. The electrostatic generator acts on the nozzle to enable the droplets sprayed by the nozzle to carry a charge, and the droplets can form powder at the receiving plate. This invention achieves the preparation of energetic composite materials based on large-size aluminum matrix through gas-phase assistance, improving the preparation efficiency of energetic composite materials; and improves the ability to control the particle size of the product by controlling the airflow field.

Description

Technical Field

[0001] This invention belongs to the field of composite material technology and relates to the preparation of composite materials, specifically to a gas-assisted coaxial electrostatic spraying device and a method for preparing aluminum-based energetic composite materials using the device. Background Technology

[0002] Electrostatic spraying is a method that uses electrostatic forces to disperse liquids into tiny droplets. It can be used to prepare micro / nano composite energetic materials with concentrated particle sizes. In particular, electrostatic spraying of aluminum powder with energetic oxidants can produce metastable intermolecular complexes (MICs). Because the reaction distance between molecules in MICs is effectively shortened, the reaction rate and mass and heat transfer processes of the energetic material are accelerated, thereby improving the energy release level of the aluminum powder. However, due to the limited electric field strength in the spraying direction, electrostatic spraying technology struggles to generate sufficient force for large-particle micron-sized aluminum powder. Therefore, currently, electrostatic spraying is mainly used for preparing nano-aluminum powder composite energetic materials, and its low preparation efficiency in preparing micron-sized aluminum powder energetic composite materials urgently needs improvement. Summary of the Invention

[0003] To address the aforementioned defects and shortcomings in the prior art, this invention provides an air-assisted coaxial electrostatic spraying device and a method for preparing aluminum-based energetic composite materials using the device, thereby solving the technical problem of low preparation efficiency of micron-sized aluminum powder composite energetic materials in the prior art.

[0004] To achieve the above objectives, the present invention employs the following technical solution:

[0005] A gas-assisted coaxial electrostatic spraying device includes a gas-liquid flow delivery unit, an electrostatic generator, and a receiving plate;

[0006] The gas-liquid flow delivery unit includes an outer tube and an inner tube coaxially sleeved together, forming an airflow cavity between the outer tube and the inner tube; the inner tube includes a liquid passage pipe and a nozzle coaxially connected together, and the nozzle has a liquid spray port at its front end; the airflow cavity is closed at its rear end and has an air outlet at its front end corresponding to the liquid spray port; an air inlet is provided on the side wall of the outer tube, and the air inlet is connected to a gas delivery device via a pipe, the gas delivery device being used to deliver gas into the airflow cavity;

[0007] The electrostatic generator includes a positive output terminal and a negative output terminal. The positive output terminal is connected to the receiving plate, and the negative output terminal is connected to the nozzle. The electrostatic generator can generate a high-voltage electrostatic field between the nozzle and the receiving plate. The droplets sprayed from the nozzle can flow from the nozzle to the receiving plate within the high-voltage electrostatic field and form powder at the receiving plate.

[0008] The present invention also has the following technical features:

[0009] Specifically, the outer tube includes a straight tube section and a conical section coaxially connected, the distance between the front end face of the conical section and the front end face of the nozzle is 1-3mm, and the distance between the front end face of the nozzle and the receiving plate is 8-15cm.

[0010] Furthermore, the nozzle is truncated cone-shaped, with its large-diameter end coaxially connected to the liquid-passing pipe, and the cone angle of the nozzle is smaller than the cone angle of the conical portion.

[0011] Furthermore, the outer tube is electrically connected to the electrostatic generator.

[0012] Furthermore, the outlet pressure of the gas conveying device is 0.1 to 0.4 MPa.

[0013] This invention also protects a method for preparing aluminum-based energetic composite materials using the above-mentioned gas-assisted coaxial electrostatic spraying device, comprising the following steps:

[0014] Step 1: Add the adhesive powder to the first organic solvent and stir until homogeneous to obtain an adhesive solution; add the micron-sized aluminum powder to the second organic solvent and stir with ultrasound and magnetic force to obtain a micron-sized aluminum powder dispersion; add the adhesive solution to the micron-sized aluminum powder dispersion and stir to obtain a micron-sized aluminum powder / adhesive dispersion.

[0015] Step 2: Add the powdered other components to the third organic solvent, and then treat with ultrasound and magnetic stirring to obtain a dispersion of the other components;

[0016] Step 3: Mix the dispersion of other components obtained in Step 2 with the micron-sized aluminum powder dispersion obtained in Step 1 to obtain the precursor dispersion;

[0017] Step 4: Connect the nozzle to the negative output terminal of the electrostatic generator and the receiving plate to the positive output terminal of the electrostatic generator to establish a high-voltage electrostatic field between the nozzle and the receiving plate; set the electrostatic spray parameters, send the precursor dispersion into the inner tube and the gas into the airflow cavity, and the droplets sprayed from the nozzle form an aluminum-based energetic composite material at the receiving plate.

[0018] The precursor solution comprises, by mass percentage, the following raw material components: 5-10% micron-sized aluminum powder, 1-3% binder, and 87-94% other components.

[0019] Furthermore, the particle size of the micron-sized aluminum powder is 1μm to 40μm, and the gas includes nitrogen, argon, and air.

[0020] Furthermore, the adhesive is selected from PVDF and PVP; the first organic solvent is selected from DMF, methanol, ethanol and tetrahydrofuran; the second and third organic solvents are both selected from acetone and ethanol or both; and the other components are selected from Fe2O3 and MeBH.

[0021] Furthermore, in step 1, the ultrasonic treatment time is 5 to 20 minutes; in step 2, the ultrasonic treatment time is 20 to 30 minutes.

[0022] Furthermore, the electrostatic spraying parameters mentioned in step 4 include: the voltage provided by the electrostatic generator is 16-23kV, the spraying rate is 8.3-33.3μL / min, the receiving distance between the receiving plate and the nozzle is 8-15cm, and the outlet air pressure of the gas delivery device is 0.2-0.4MPa.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] (1) The gas-assisted coaxial electrostatic spraying device provided by the present invention not only realizes the preparation of large-size aluminum-based energetic composite materials through gas phase assistance, but also greatly improves the preparation efficiency of energetic composite materials.

[0025] (2) The air-assisted coaxial electrostatic spraying device provided by the present invention can realize the preparation of micron-sized aluminum-based energetic composite materials, which solves the dilemma that conventional electrostatic spraying technology can only prepare nano-aluminum powder energetic composite materials, and further solves the technical problem that nano-aluminum powder is easy to react with water and oxygen in the air, thus hindering the application of composite energetic materials containing nano-aluminum powder in propellants.

[0026] (3) The method for preparing aluminum-based energetic composite materials provided by the present invention combines coaxial electrostatic spraying technology with gas phase assistance, which can greatly improve the preparation efficiency of energetic composite materials. Attached Figure Description

[0027] The accompanying drawings are provided to further understand the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof.

[0028] Figure 1 A schematic diagram of the overall structure of a gas-assisted coaxial electrostatic spray device;

[0029] Figure 2 Here is a SEM image of the Al / PVDF / Fe2O3 energetic composite material prepared in Example 2;

[0030] Figure 3 SEM image of the Al / PVDF / Fe2O3 energetic composite material prepared in Comparative Example 1;

[0031] Figure 4 SEM image of Al / PVP / MeBH obtained in Example 3;

[0032] Figure 5 SEM image of Al / PVP / MeBH prepared in Comparative Example 2;

[0033] Figure 6 The combustion of Al / PVP / MeBH prepared in Example 3 at the propellant combustion surface is shown.

[0034] The symbols in the diagram represent:

[0035] 1-Outer pipe, 2-Inner pipe, 3-Pipe, 4-Receiving plate; 11-Straight pipe section, 12-Conical section; 21-Liquid passage pipe, 22-Nozzle.

[0036] The technical solution of the present invention will be further described below with reference to the embodiments. Detailed Implementation

[0037] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, any other embodiments obtained by those skilled in the art are within the scope of protection of the present invention.

[0038] The technical concept of this application is as follows: Using an outer and inner tube coaxially fitted together in a coaxial electrostatic spraying device as the core structure, airflow enters the airflow chamber through a pipe perpendicular to the outer tube, and contacts the precursor dispersion at the outlet, causing the precursor dispersion droplets to atomize. An electrostatic generator causes the atomized droplets to carry a charge, generating electrostatic spray. The auxiliary effect provided by the airflow significantly enhances the transport capacity of the electrostatic spray in the spray direction. Furthermore, the airflow field helps to further fragment the droplets. By effectively combining the direct forces of the electrostatic field and the airflow field on the droplets, and by controlling the magnitude of the airflow field, sufficient driving force is generated for large-particle-size micron-sized aluminum powder. This causes the precursor dispersion to form a funnel-shaped liquid jet under the action of a high-voltage electrostatic field. After traveling a certain distance, the liquid jet evaporates along with the solvent and finally deposits at the receiving plate, forming an aluminum-based energetic composite material powder composed of micron-sized aluminum powder.

[0039] The scanning electron microscope (SEM) images in the following examples were obtained using a Hitachi S4800 SEM from Japan.

[0040] Unless otherwise specified, all components and raw materials used in the following embodiments of the present invention are commercially available.

[0041] Example 1

[0042] Following the above technical solutions, such as Figure 1 As shown, this embodiment provides a gas-assisted coaxial electrostatic spraying device, including a gas-liquid flow conveying unit, an electrostatic generator, and a receiving plate 4;

[0043] The gas-liquid flow conveying unit includes an outer tube 1 and an inner tube 2 coaxially sleeved together, forming an airflow cavity between the outer tube 1 and the inner tube 2. The inner tube 2 includes a liquid-passing pipe 21 and a nozzle 22 coaxially connected together, with a liquid spraying port at the front end of the nozzle 22. The airflow cavity is closed at the rear end and has an air outlet at the front end corresponding to the liquid spraying port. An air inlet is provided on the side wall of the outer tube 1, and the air inlet is connected to a gas conveying device via a pipe 3. The gas conveying device is used to send gas into the airflow cavity, and the gas flowing through the airflow cavity can atomize the liquid material flowing out of the nozzle into droplets. In this embodiment, the gas conveying device includes an air compressor or an N2 / Ar gas cylinder; the pipe 3 is arranged perpendicularly to the outer tube 1.

[0044] The inlet of the liquid-passing tube 21 is connected to a syringe, and a micro-injection pump is connected to the syringe. The syringe is used to push liquid material into the liquid-passing tube 21.

[0045] The electrostatic generator includes a positive output terminal and a negative output terminal. The positive output terminal is connected to the receiving plate 4, and the negative output terminal is connected to the nozzle 22. The electrostatic generator can generate a high-voltage electrostatic field between the nozzle 22 and the receiving plate 4. The droplets sprayed from the nozzle 22 can flow from the nozzle 22 to the receiving plate 4 in the high-voltage electrostatic field and form powder at the receiving plate 4.

[0046] In this embodiment, the gas flowing through the airflow cavity is an inert gas, including nitrogen, argon and air. The airflow provides flow assistance to the liquid material sprayed through the nozzle 22. At the same time, the high-speed airflow breaks up the liquid droplets, increases the specific surface area of ​​the droplets, and improves the solvent evaporation rate, thereby realizing the combination of gas phase spraying and electrostatic high-pressure spraying.

[0047] As a preferred embodiment, the outer tube 1 includes a straight tube portion 11 and a conical portion 12 coaxially connected. The distance between the front end face of the conical portion 12 and the front end face of the nozzle 22 is 1-3 mm, and the distance between the front end face of the nozzle 22 and the receiving plate 4 is 8-15 cm.

[0048] As a preferred embodiment, the nozzle 22 is truncated cone-shaped, with the large-diameter end of the nozzle 22 coaxially connected to the liquid pipe 21, and the cone angle of the nozzle 22 is smaller than the cone angle of the cone portion 12.

[0049] As a preferred embodiment, the outer tube 1 is electrically connected to the electrostatic generator, and the voltage provided by the electrostatic generator is 16-23kV.

[0050] As a preferred embodiment, the outlet pressure of the gas conveying device is 0.1 to 0.4 MPa.

[0051] When using this embodiment:

[0052] The precursor dispersion is fed into the inner tube 2 using a syringe. The outlet pressure of the gas delivery device is set, and the gas delivery device is turned on to send gas into the airflow cavity. The electrostatic generator is turned on to generate a high-voltage electrostatic field. The airflow comes into contact with the precursor dispersion. Under the high-voltage electrostatic action of the high-voltage electrostatic field, a funnel-shaped liquid jet is formed. After traveling a certain distance, the liquid jet evaporates along with the solvent and finally deposits at the receiving plate to form composite material powder.

[0053] Example 2

[0054] This embodiment provides a method for preparing Al / PVDF / Fe2O3 energetic composite materials using the gas-assisted coaxial electrostatic spraying device disclosed in Example 1, specifically including:

[0055] (1) Preparation of Al / PVDF dispersion

[0056] 20 mg of PVDF powder was added to 3 ml of DMF and stirred for 20 min to obtain a PVDF solution; 1 g of aluminum powder (particle size 13 μm) was added to 7 ml of acetone, sonicated for 10 min and then magnetically stirred to obtain an acetone dispersion of micron-sized aluminum powder; the PVDF solution was added to the acetone dispersion of aluminum powder and mixed and stirred to obtain an Al / PVDF dispersion.

[0057] (2) Preparation of Fe2O3 suspension

[0058] Take 10 mg of Fe2O3 powder and add 10 ml of acetone. After ultrasonic dispersion for 30 min, stir magnetically to obtain an acetone suspension of Fe2O3.

[0059] (3) Prepare precursor dispersion

[0060] Mix 10 ml of Al / PVDF suspension with 10 ml of Fe2O3 suspension and stir magnetically for 12 h to obtain a precursor dispersion.

[0061] (4) The nozzle is connected to the negative output terminal of the electrostatic generator, and the receiving plate is connected to the positive output terminal of the electrostatic generator. A high-voltage electrostatic field is established between the nozzle and the receiving plate, and the distance between the nozzle and the receiving plate is set to 15-20 cm. The precursor dispersion is sent into the inner tube, the outlet gas pressure of the gas delivery device is set to 0.2 MPa, nitrogen is sent into the gas flow chamber, and the voltage provided by the electrostatic generator is set to 18 kV, so that the droplets sprayed from the nozzle carry a charge. The droplets flow from the nozzle to the receiving plate in the high-voltage electrostatic field, and finally a dark red powdery product is obtained at the receiving plate. The powder on the receiving plate is collected with a wooden spoon, freeze-dried, and weighed. The mass of the dark red powdery product obtained is 768 mg. Figure 6 The yield was 74.5%.

[0062] Figure 2 This is a SEM image of the Al / PVDF / Fe2O3 energetic composite material prepared in this embodiment; from Figure 2 (a) It is visible that there is a large amount of powder deposited on the surface of the aluminum foil on the collecting plate; Figure 2 (b) This indicates that the powder is large-size aluminum powder (average particle size 13 micrometers); Figure 2 (c) The distribution of Al and Fe elements is basically consistent. There are a large number of spherical particles of Al, indicating that an Al / PVDF / Fe2O3 energetic composite material has been formed.

[0063] Comparative Example 1

[0064] This embodiment provides a method for preparing Al / PVDF / Fe2O3 energetic composite materials using an existing coaxial electrostatic spraying device. The preparation steps and raw material components are the same as in Example 1. The difference is that the existing coaxial electrostatic spraying device only has an electrostatic field acting directly on the droplets and lacks additional forces.

[0065] After coaxial electrostatic spraying preparation, the powder on the receiving plate was collected with a wooden spoon, freeze-dried, and the dark red powder Al / PVDF / Fe2O3 energetic composite material was obtained and weighed.

[0066] Figure 3 The image shows a SEM image of the Al / PVDF / Fe2O3 energetic composite material prepared in this comparative example. As can be seen from the image, the aluminum foil surface on the receiving plate contains only a small number of spherical particles, while the remaining area consists of nano-sized Fe2O3. Meanwhile, the product yield is only 126 mg ( Figure 6 The yield was 12.2%.

[0067] As can be seen from Example 2 and Comparative Example 1, in Comparative Example 1, the electrostatic field alone is insufficient to transport droplets to the sample receiving plate, resulting in only large-sized powder particles on the aluminum foil surface of the receiving plate. This indicates that the coaxial electrostatic spraying device used in Comparative Example 1 lacks the ability to further control the powder particle size, making it difficult to efficiently prepare large-sized Al / PVDF / Fe2O3 energetic composite materials. In contrast, Example 2, through the combined effect of gas-phase assistance and a high-voltage electrostatic field, can efficiently prepare Al / PVDF / Fe2O3 energetic composite materials based on large-sized (13μm) aluminum powder. Data comparison shows that the yield using the method of this invention is 6.1 times higher than that using only a high-voltage electrostatic field.

[0068] Example 3

[0069] This embodiment provides a method for preparing Al / PVP / MeBH energetic composite materials using the gas-assisted coaxial electrostatic spraying device disclosed in Example 1, specifically including the following steps:

[0070] (1) Preparation of Al / PVP dispersion

[0071] 1 g of micron-sized aluminum powder was dispersed in 10 ml of ethanol and subjected to ultrasonic and magnetic stirring to obtain a micron-sized aluminum powder dispersion. 40 mg of polyvinylpyrrolidone (PVP) was added to the micron-sized aluminum powder dispersion. The dispersion was subjected to ultrasonic treatment for 10 min and magnetic stirring for 20 min to obtain an Al / PVP dispersion.

[0072] (2) Preparation of MeBH dispersion

[0073] Disperse 200 mg MeBH in 10 ml of ethanol, sonicate for 10 min and stir magnetically for 25 min to obtain an ethanol dispersion of MeBH.

[0074] (3) Prepare precursor dispersion

[0075] The ethanol dispersion of MeBH was added to the Al / PVP dispersion and stirred for 12 hours to obtain the Al / PVP / MeBH precursor dispersion.

[0076] (4) The nozzle is connected to the negative output terminal of the electrostatic generator, and the receiving plate is connected to the positive output terminal of the electrostatic generator. A high-voltage electrostatic field is established between the nozzle and the receiving plate, and the distance between the nozzle and the receiving plate is set to 15-20 cm. The Al / PVP / MeBH precursor dispersion is fed into the inner tube, the outlet gas pressure of the gas delivery device is set to 0.2 MPa, nitrogen is fed into the gas flow chamber, and the voltage provided by the electrostatic generator is set to 20 kV, so that the droplets sprayed from the nozzle carry a charge. The droplets flow from the nozzle to the receiving plate in the high-voltage electrostatic field, and finally a gray powder product is obtained at the receiving plate. The gray powder on the receiving plate is collected with a wooden spoon, freeze-dried, and weighed. The mass of the product obtained is 815 mg, and the yield is 65.7%.

[0077] As can be seen from the SEM image of the Al / PVP / MeBH energetic composite material prepared in this embodiment, a large amount of powder is deposited on the surface of the aluminum foil on the collecting plate, while Figure 4 (c) and Figure 4 (d) and EDS elemental distribution diagram: The powder contains a large amount of B element, and Al and B elements are closely distributed, indicating that Al and MeBH are closely combined through PVP.

[0078] The combustion of the Al / PVP / MeBH energetic composite material prepared in this embodiment at the propellant combustion surface was monitored, and the results are as follows: Figure 6 As shown, from Figure 6 The splitting process of the two molten aluminum spheres can be seen, indicating that the presence of MeBH can effectively inhibit the melting and agglomeration process of Al.

[0079] Comparative Example 2

[0080] This embodiment provides a method for preparing Al / PVP / MeBH energetic composite materials using an existing coaxial electrostatic spraying device. The preparation steps and raw material components are the same as in Example 3. The difference is that the existing coaxial electrostatic spraying device only has an electrostatic field acting directly on the droplets, lacking additional forces, making it difficult to transport the droplets to the sample receiving plate. After coaxial electrostatic spraying preparation, the powder on the receiving plate is collected with a wooden spoon, freeze-dried, and a gray powder product is obtained and weighed. The product mass is 65 mg, and the yield is 5.2%.

[0081] Figure 5 The image shows a SEM image of the Al / PVP / MeBH energetic composite material prepared in this comparative example. As can be seen from the image, there is a large amount of powder deposited on the surface of the aluminum foil on the receiving plate, but only a very small amount of white powder. After testing, the product is mostly MeBH / PVP, with only a few Al / PVP / MeBH particles.

[0082] As can be seen from Example 3 and Comparative Example 2, it is difficult to efficiently prepare large-sized Al / PVP / MeBH energetic composite materials by relying solely on the effect of an electrostatic field. However, by combining the effects of gas-phase assistance and a high-voltage electrostatic field, Al / PVP / MeBH energetic composite materials based on large-sized (13μm) aluminum powder can be prepared efficiently. The yield using the method of this invention is 12.6 times higher than that of the existing coaxial electrostatic spraying method that relies solely on a high-voltage electrostatic field.

[0083] In summary, the gas-assisted coaxial electrostatic spraying device provided by this invention forms an airflow cavity between an outer tube and an inner tube that are coaxially fitted together. The airflow enters the airflow cavity through a pipe perpendicular to the outer tube and comes into contact with the precursor dispersion at the outlet. Under the action of a high-voltage electrostatic field, a funnel-shaped liquid jet is formed. After traveling a certain distance, the liquid jet evaporates along with the solvent and is finally deposited at the receiving plate to form aluminum-based energetic composite material powder composed of micron-sized aluminum powder. This gas-assisted approach enables the preparation of large-size aluminum-based energetic composite materials and significantly improves the preparation efficiency of energetic composite materials.

[0084] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0085] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for producing an aluminum-based energetic composite material, characterized in that, This method is achieved through a gas-assisted coaxial electrostatic spraying device, which includes a gas-liquid flow conveying unit, an electrostatic generator, and a receiving plate (4). The gas-liquid flow transport unit includes a coaxially sleeved metal outer tube (1) and inner tube (2), forming an airflow cavity between the outer tube (1) and the inner tube (2); the inner tube (2) includes a coaxially connected liquid passage pipe (21) and a nozzle (22), with a liquid spray port at the front end of the nozzle (22); the airflow cavity is closed at the rear end and has an air outlet at the front end corresponding to the liquid spray port; an air inlet is provided on the side wall of the outer tube (1), and the air inlet is connected to a gas transport device via a pipe (3), which is used to send gas into the airflow cavity; The electrostatic generator includes a positive output terminal and a negative output terminal. The positive output terminal is connected to the receiving plate (4), and the negative output terminal is connected to the nozzle (22). The electrostatic generator can generate a high-voltage electrostatic field between the nozzle (22) and the receiving plate (4). The droplets sprayed from the nozzle (22) can flow from the nozzle (22) to the receiving plate (4) in the high-voltage electrostatic field and form powder at the receiving plate (4). The method includes the following steps: Step 1: Add the adhesive powder to the first organic solvent and stir until homogeneous to obtain an adhesive solution; add the micron-sized aluminum powder to the second organic solvent and stir with ultrasound and magnetic force to obtain a micron-sized aluminum powder dispersion; add the adhesive solution to the micron-sized aluminum powder dispersion and stir to obtain a micron-sized aluminum powder / adhesive dispersion. Step 2: Add the other component powders to the third organic solvent, and then treat with ultrasound and magnetic stirring to obtain a dispersion of the other components; Step 3: Mix the dispersion of other components obtained in Step 2 with the micron-sized aluminum powder dispersion obtained in Step 1 to obtain the precursor dispersion; Step 4: Connect the nozzle to the negative output terminal of the electrostatic generator and the receiving plate to the positive output terminal of the electrostatic generator to establish a high-voltage electrostatic field between the nozzle and the receiving plate; set the electrostatic spray parameters, send the precursor dispersion into the inner tube and the gas into the airflow cavity, and the droplets sprayed from the nozzle form an aluminum-based energetic composite material at the receiving plate. The precursor dispersion comprises, by mass percentage, the following raw material components: 5-10% micron-sized aluminum powder, 1-3% binder, and 87-94% other components.

2. The method as described in claim 1, characterized in that, The outer tube (1) includes a straight tube section (11) and a conical section (12) that are coaxially connected. The distance between the front end face of the conical section (12) and the front end face of the nozzle (22) is 1~3mm, and the distance between the front end face of the nozzle (22) and the receiving plate (4) is 8~15cm.

3. The method as described in claim 2, characterized in that, The nozzle (22) is truncated cone-shaped. The large-diameter end of the nozzle (22) is coaxially connected to the liquid pipe (21), and the cone angle of the nozzle (22) is smaller than the cone angle of the conical part (12).

4. The air-assisted coaxial electrostatic spraying device as described in claim 1, characterized in that, The outer tube (1) is electrically connected to the electrostatic generator.

5. The air-assisted coaxial electrostatic spraying device as described in claim 1, characterized in that, The outlet pressure of the gas conveying device is 0.1 to 0.4 MPa.

6. The method as described in claim 1, characterized in that, The particle size of the micron-sized aluminum powder is 1μm to 40μm, and the gas includes nitrogen, argon and air.

7. The method as described in claim 1, characterized in that, The adhesive is selected from PVDF and PVP; the first organic solvent is selected from DMF, methanol, ethanol and tetrahydrofuran; the second and third organic solvents are both selected from acetone and ethanol or both; the other components are selected from Fe2O3 and MeBH.

8. The method as described in claim 1, characterized in that, In step 1, the ultrasonic treatment time is 5-20 minutes; in step 2, the ultrasonic treatment time is 20-30 minutes.

9. The method as described in claim 1, characterized in that, The electrostatic spraying parameters mentioned in step 4 include: the voltage provided by the electrostatic generator is 16-23kV, the receiving distance between the receiving plate and the nozzle is 8-15cm, and the outlet air pressure of the gas delivery device is 0.2-0.4Mpa.

Images