A powder ultrasonic-assisted coating device and method based on high-power multi-arc ion plating

Abstract

This invention discloses a powder ultrasonic-assisted coating device and method based on high-power multi-arc ion plating, relating to the fields of vacuum multi-arc coating and powder surface modification technology. The device comprises a coating chamber, a vacuum pumping system, a gas supply system, a dual-target multi-arc system, a grid biasing device, a powder tray, a powder heating device, an ultrasonic auxiliary device, a powder driving mechanism, and a water cooling system. The invention symmetrically arranges two high-power multi-arc targets at the top of the reaction chamber. High-density plasma spots are formed by electric arcs, evaporating and ionizing target atoms to generate an ion flow, which simultaneously deposits onto the powder bed from both sides. The ion flows from both sides converge, eliminating the incident dead angle of single-target deposition and ensuring sufficient coating on all particle surfaces. The dual-target materials can be selected independently to achieve integrated preparation of composite or gradient films, resulting in a uniform and dense coating.

Description

Technical Field

[0001] This invention belongs to the field of vacuum multi-arc coating and powder surface modification technology, specifically a powder ultrasonic-assisted coating device and method based on high-power multi-arc ion plating. Background Technology

[0002] Powders can be used as raw materials for cold spraying to prepare multifunctional coatings and metal matrix composites. High-hardness ceramic particles, such as SiC or Al2O3, have extremely low plasticity and hardly undergo plastic deformation during high-speed impacts. This makes it difficult for particles to form close contact with each other and with the matrix, resulting in porosity and unbonded interfaces within the coating. These ceramic particles are prone to fracture during impacts, and their fragments can cause localized stress concentrations and microcracks, increasing coating porosity and decreasing density. Furthermore, ceramic powders and metal powders exhibit significant differences in gas dynamics; metal powders tend to deposit preferentially, while ceramic particles are prone to rebound and loss, causing the coating composition to deviate from the designed ratio and resulting in insufficient retention of the reinforcing phase, thereby reducing the coating's bonding strength and wear resistance.

[0003] Powder coating, by coating hard particles with a plastic metal shell to form a core-shell structured composite powder, can effectively improve the aforementioned problems. During the high-speed impact of cold spraying, the plastic metal shell preferentially undergoes plastic deformation and localized shear deformation at the contact interface, causing the surface oxide layer to crack or peel off, exposing a fresh metal surface. This increases the effective contact area between the shell and the substrate or adjacent particles, forming a stronger interfacial bond. The metal shell also serves as a deformation-bearing layer for the hard core, giving the originally poorly plastic hard particles a certain degree of deposition adaptability, reducing the probability of particle rebound and coating porosity. Simultaneously, the plastic metal shell can absorb some impact energy, alleviating the instantaneous impact stress borne by the hard core, reducing ceramic particle breakage, and helping to maintain the integrity of the reinforcing phase structure. Furthermore, the core-shell structure allows the mechanical response and deposition behavior of different component powders to be more similar during cold spraying, thereby mitigating selective deposition and component segregation problems, and improving coating density, reinforcing phase retention rate, and interfacial bonding strength.

[0004] The core challenge of powder coating lies in the tendency of powder to agglomerate and the difficulty in maintaining sufficient dispersion. This results in uneven exposure time of individual particle surfaces to the coating atmosphere, making it impossible to achieve continuous and uniform coating and form a stable core-shell structure with complete structure and consistent shell thickness. This severely affects the actual effect of functional modification. CN219526771U discloses a micro / nano powder coating device for semiconductor devices, which uses a polygonal roller to drive the powder to tumble and perform magnetron sputtering coating. Although this method can improve powder dispersion, it is still difficult to avoid powder accumulation, obstruction, and agglomeration, resulting in uneven exposure of particle surfaces and insufficient shell thickness consistency. At the same time, the ion bombardment effect of magnetron sputtering on the powder is relatively weak, and the film adhesion is usually not as good as that of multi-arc ion plating. In the process of multi-arc ion plating, the powder is in a state of motion and dispersion, making it difficult to apply a stable negative bias voltage, resulting in insufficient ion bombardment effect, which in turn affects the film density and adhesion. Therefore, how to form a stable bias electric field during the powder coating process to accelerate ions and improve film adhesion is a technical problem that needs to be solved in this field.

[0005] The information disclosed above in this background section is only for enhancing the understanding of the background section of this invention, and therefore may include prior art that is not known to those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide a powder ultrasonic-assisted coating device and method based on high-power multi-arc ion plating, so as to solve the problems in the prior art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a powder ultrasonic-assisted coating device based on high-power multi-arc ion plating, comprising:

[0008] The coating chamber forms a vacuum reaction chamber inside, which is used to hold the powder to be coated and provide a reaction space for powder coating.

[0009] The vacuum pumping system is connected to the vacuum reaction chamber through a pumping pipeline and is used to establish and maintain the vacuum environment required for the coating process.

[0010] A gas supply system is used to introduce working gas and reaction gas into the vacuum reaction chamber, and is connected to the vacuum reaction chamber through a gas supply pipeline.

[0011] The dual-target multi-arc system includes two targets symmetrically arranged at the top of the vacuum reaction chamber, and uses high-power pulse-enhanced multi-arc ion plating to achieve powder film deposition.

[0012] A grid biasing device is disposed in the vacuum reaction chamber and located above the powder carrying area. It is used to apply a negative bias to the area above the powder to accelerate film-forming ions and improve film adhesion and deposition uniformity.

[0013] A powder tray, located inside the vacuum reaction chamber, is used to hold the powder to be coated. The powder tray is detachable and connected to a rotating shaft and a heating element to receive the vibration transmitted by the ultrasonic auxiliary device, thereby promoting powder suspension.

[0014] A powder heating device is installed inside the vacuum reaction chamber to regulate the temperature of the powder to be coated, thereby improving the film growth state.

[0015] An ultrasonic auxiliary device includes an ultrasonic generator and an ultrasonic amplitude transformer. The ultrasonic amplitude transformer acts on the powder bearing area to apply high-frequency vibration to the powder, so that the powder is in a suspended state and the coating uniformity of the particle surface is improved.

[0016] The powder driving mechanism, including a rotary motor and a bevel gear transmission assembly, is used to drive the powder tray to rotate continuously during the coating process, so that the powder remains in motion.

[0017] The water cooling system, including cooling water inlet pipe and cooling water outlet pipe, is used to circulate and cool the coating chamber and the target to ensure temperature stability under high-power multi-arc ion plating conditions.

[0018] Preferably, the two targets of the dual-target multi-arc system can be fitted with the same material to achieve uniform deposition of a single film layer, or targets with different compositions can be fitted separately to prepare composite films.

[0019] Preferably, the ultrasonic auxiliary device works in conjunction with the powder driving mechanism to keep the powder to be coated in a state of dynamic suspension, continuous turning and uniform spreading in the powder tray, so that the powder particles are uniformly exposed to the film-forming ion flow, thereby improving the coating uniformity of the film layer on the powder surface.

[0020] Preferably, the powder to be coated is in a dynamic suspension state during the coating process, making it difficult to directly apply a stable bias voltage, which may result in problems such as weak film adhesion. The grid bias device is set above the powder bearing area to form a negative bias electric field and accelerate the entry of film-forming metal ions into the area, thereby improving the compactness, adhesion strength and deposition uniformity of the film layer on the powder surface.

[0021] A powder ultrasonic-assisted coating method based on high-power multi-arc ion plating includes the following steps:

[0022] Step 1, Pre-spreading powder and adjusting powder movement:

[0023] Add the powder to be coated into the powder tray, start the ultrasonic auxiliary device and powder drive mechanism, adjust the ultrasonic parameters and rotation parameters to make the powder to be coated form a loose, flat, dynamically suspended and continuously turning state in the tray. After the requirements are met, turn off the ultrasonic generator and the rotary motor.

[0024] Step two, cooling, preheating and vacuuming:

[0025] Close the coating chamber, turn on the water cooling system, powder heating device and vacuum pumping system to evacuate the vacuum reaction chamber and preheat the powder to be coated so that the vacuum reaction chamber reaches the set vacuum level.

[0026] Step 3, Ultrasonic Suspension Assisted Multi-Arc Ion Plating:

[0027] After the vacuum reaction chamber reaches the set vacuum level, the ultrasonic auxiliary device and rotary motor are restarted according to the parameters determined in the pre-powdering stage to keep the powder in a dynamic suspension and continuous tumbling uniform coating state. Then, Ar and other gases are introduced, the grid bias device is turned on to accelerate the film-forming ions, and the dual-target multi-arc system is started to start the arc and stabilize the deposition, so that the film-forming ions are deposited on the powder surface to form a continuous, dense and uniform film layer.

[0028] Step 4: Deflating the cavity and removing powder:

[0029] After the coating is completed, shut down the dual-target multi-arc system, grid bias device, gas supply system, powder heating device and vacuum pumping system. After the cavity cools down and returns to normal pressure, open the coating chamber and take out the coated composite powder.

[0030] Preferably, in step one, the ultrasonic frequency of the ultrasonic auxiliary device is 20-40kHz, the ultrasonic power is 100-800W, and the amplitude is 5-50μm; the rotation speed of the powder tray is 5-60r / min. By adjusting the ultrasonic frequency, ultrasonic power, amplitude, and tray rotation speed, the powder to be coated is made to form a loose, flat, dynamically suspended, and continuously tumbling state in the tray.

[0031] Preferably, in step two, the powder heating device preheats the powder to be plated at a temperature of 100–300°C to improve the surface activity of the powder and enhance the growth quality and bonding stability of the film during subsequent ion plating.

[0032] Preferably, in step two, the vacuum pumping system evacuates the vacuum reaction chamber to achieve a vacuum level of 5 × 10⁻⁶. -3 The pressure is below 100 Pa to meet the process requirements for subsequent ventilation and dual-target multi-arc ion plating deposition.

[0033] Preferably, in step three, a working gas such as Ar is introduced into the vacuum reaction chamber, wherein the Ar gas flow rate is 20-80 sccm, so that the working pressure in the vacuum reaction chamber is maintained at 0.2-0.8 Pa; if a nitride film is to be prepared, N2 is introduced at the same time, and the N2 gas flow rate is 5-100 sccm. By adjusting the flow rate ratio of Ar and N2, the composition and growth state of the deposited film are controlled.

[0034] Preferably, in step three, the negative bias voltage applied by the grid biasing device is -50 to -300V, and the magnitude of the negative bias voltage is adjusted according to the target material and the type of target film.

[0035] Preferably, in step three, the dual-target multi-arc system is started, and the arc is first started on the two targets with an arc-starting current of 55A; after the arc forms a stable arc spot on the target surface, the arc current of the two targets is adjusted to 60-150A; when the high-power pulse enhancement mode is used, the pulse current is 80-500A, the pulse frequency is 0.1-5kHz, and the duty cycle is 10%-80%.

[0036] Preferably, in step three, the dual-target multi-arc system adopts an intermittent deposition method, that is, after continuous deposition for a period of time, the target source deposition is paused, and the ultrasonic auxiliary device and the rotary motor are kept running during the pause to reduce powder overheating, agglomeration and uneven local growth of the film layer.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. This invention symmetrically arranges two high-power multi-arc targets at the top of the reaction chamber. A high-density plasma spot is formed by an electric arc, evaporating and ionizing target atoms to generate an ion flow that simultaneously deposits onto the powder bed from both sides. The ion flows from both sides converge, eliminating the incident dead angle of single-target deposition and ensuring sufficient coating on all particle surfaces. The dual-target materials can be selected independently, enabling the integrated preparation of composite or gradient films, resulting in a uniform and dense coating.

[0039] 2. Since the powder to be coated is in a suspended state during the coating process, it is difficult to apply a stable bias voltage directly like a bulk workpiece. Therefore, this invention sets up a grid bias device above the powder-bearing area. By applying a negative bias voltage to the grid, an accelerating electric field is formed in front of the target, giving the metal ions in this area additional kinetic energy. The high-energy ions accelerate through the grid, enhancing their bombardment and deposition effect on the powder surface. This method does not require direct contact between the powder and the bias power supply, and can control the ion energy around the powder. Combined with the continuous agitation and dynamic suspension of the powder, different surfaces of the particles can be alternately exposed to the deposition ion flow, thereby improving the continuity, density, and thickness uniformity of the coating on the powder surface.

[0040] 3. This invention uses a rotating mechanism to drive a detachable powder tray to rotate continuously, causing the powder within the tray to be subjected to centrifugal force and spread and migrate along the tray surface. Simultaneously, an ultrasonic amplitude transformer transmits high-frequency mechanical vibration to the tray and powder bed, causing the powder particles to vibrate and dynamically suspend, reducing particle agglomeration and accumulation. The spreading effect generated by rotation and the vibrational suspension effect caused by ultrasound work together to continuously tumble and loosely distribute the powder within the tray, constantly changing its deposition position. Therefore, individual particles do not remain fixed in one area but continuously change position on the tray surface and within the powder layer, allowing different surfaces of the particles to be alternately exposed to the deposition ion flow, thereby improving the continuity, uniformity, and shell thickness consistency of the powder coating. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0042] Figure 1 This is a schematic diagram of the powder ultrasonic-assisted coating device based on high-power multi-arc ion plating according to the present invention.

[0043] In the picture:

[0044] 1. Air supply pipeline; 2. Cooling water inlet pipeline; 3. Grid bias device; 4. Grid bias power supply; 5. Powder heating device; 6. Vacuum pumping system; 7. Dual-target multi-arc system; 8. High-power, high-stability pulse arc power supply; 9. Powder tray; 10. Cooling water outlet pipeline; 11. Bevel gear transmission assembly; 12. Rotary motor; 13. Ultrasonic amplitude transformer; 14. Ultrasonic generator. Detailed Implementation

[0045] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings. 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.

[0046] Example 1:

[0047] This embodiment provides an ultrasonic-assisted Ti film deposition method for Al powder based on high-power multi-arc ion plating. Through the synergistic effects of dual-target multi-arc deposition, grid negative bias ion acceleration, and ultrasonic levitation, the Al powder remains dynamically suspended and continuously tumbling during the deposition process, and is uniformly exposed to the high-speed Ti ion flow, thereby forming a continuous and dense Ti film on the Al powder surface, obtaining a core-shell structured Al@Ti composite powder. The specific operation steps are as follows.

[0048] Step 1, Pre-spreading powder and adjusting powder movement:

[0049] Open the coating chamber and pour the Al powder to be coated into the powder tray 9 according to the set filling amount. Initially spread the powder to form a relatively uniform powder layer at the bottom of the tray. Then, install the powder tray 9 onto the powder-bearing rotating shaft, ensuring reliable contact between the ultrasonic amplitude transformer 13 and the bottom of the tray or the powder-bearing area. Start the ultrasonic generator 14 and the rotary motor 12, causing the tray to rotate and circumferentially tumble the powder. Simultaneously, high-frequency vibration is transmitted to the tray and powder bed through the ultrasonic amplitude transformer 13. The ultrasonic frequency can be selected as 40kHz, the ultrasonic power as 100W, and the amplitude as 10μm; the tray rotation speed can be selected as 10r / min. Adjust the ultrasonic power, amplitude, and tray rotation speed according to the powder particle size, density, and filling amount to ensure the powder forms a loose, flat, dynamically suspended, and continuously tumbling state within the tray, preventing powder accumulation or agglomeration. Once the powder movement reaches the preset requirements, turn off the ultrasonic generator 14 and the rotary motor 12, confirm that there are no abnormalities in the tray installation and sealing parts, close the coating chamber door, and proceed to the subsequent vacuuming and coating processes.

[0050] Step two, cooling, preheating and vacuuming:

[0051] After pre-laying the powder, close the coating chamber door and check the sealing status of the door seals, observation windows, and all pipe interfaces to ensure the vacuum reaction chamber is reliably sealed. Then, turn on the water cooling system to circulate cooling for the chamber, target holder, and related heat-generating components. Start the powder heating device 5 to preheat the tray and the powder to be coated. The heating temperature can be set to 100℃ to improve the powder surface activity and enhance the growth quality and bonding stability of the film during subsequent ion plating. Simultaneously, start the vacuum pumping system 6. First, start the mechanical pump for rough evacuation for 10 minutes to reduce the chamber pressure to below 10 Pa. Once the rough vacuum reaches the high vacuum pump start-up conditions, start the molecular pump for 30 minutes until the vacuum chamber's base vacuum reaches 5 × 10⁻⁶ Pa. -3 Below Pa. After the water cooling, heating and vacuum conditions have all reached the set requirements, proceed to the subsequent arc initiation and deposition coating steps.

[0052] Step 3, Ultrasonic Suspension Assisted Multi-Arc Ion Plating:

[0053] After the vacuum reaction chamber reaches the set background vacuum level, the rotary motor 12 and the ultrasonic auxiliary device are restarted, and the operating parameters determined in step one during pre-powder spreading are invoked to restore the powder to a loose, dynamically suspended, and continuously tumbling state within the tray. The operating parameters, including ultrasonic frequency, ultrasonic power, amplitude, and tray rotation speed, are based on the specific values ​​obtained during the pre-powder spreading stage and are maintained stably throughout the coating process. The powder state is constantly observed through the observation window. If the powder state changes due to temperature, atmosphere, or the deposition process, the ultrasonic power or tray rotation speed can be fine-tuned within a small range to maintain the dynamic suspension and uniform coating state of the powder.

[0054] Subsequently, Ar gas is introduced into the vacuum reaction chamber at a flow rate of 50 sccm to maintain the working pressure at 0.5 Pa. Once the pressure stabilizes, the grid bias device 3 is activated to apply a negative bias voltage to the grid located above the powder-bearing area. The bias voltage value can be set to -100V. The grid bias device 3 is paired with a grid bias power supply 4. By controlling the ion energy near the powder-bearing area through the negative grid bias voltage, the bombardment and deposition of film-forming ions on the powder surface is enhanced.

[0055] After completing the atmosphere and bias voltage adjustments, the dual-target multi-arc system 7 is activated. The target material is Ti. The dual-target multi-arc system 7 is equipped with a high-power, high-stability pulsed arc power supply 8. First, the two targets are ignited to form a stable arc spot on the target surface. The ignition current can be set to 55A, and the ignition stabilization time can be 1 minute. A lower arc current is used in the initial stage of ignition to reduce the impact of unstable ion current on the powder surface deposition quality. After the arc combustion stabilizes, the arc current of the two targets is adjusted to 80A. When using the high-power pulse enhancement mode, the pulse current is 200A, the pulse frequency can be set to 200Hz, and the duty cycle can be set to 20%.

[0056] After the target source stabilizes, the film-forming ion flow continuously enters the powder-bearing area and deposits on the powder surface. During the coating process, the ultrasonic, rotation, gas supply, grid bias, and dual-target multi-arc system operate synchronously, keeping the powder in a dynamic suspension and tumbling state, with different particle surfaces alternately exposed to the deposited ion flow. To avoid powder overheating, agglomeration, or uneven film growth, an intermittent coating method can be used. The total coating time can be set to 180 minutes based on the target shell thickness. Through the above process, a continuous, dense, and relatively uniform Al@Ti composite powder is formed on the powder surface.

[0057] Step 4: Deflating the cavity and removing powder:

[0058] After coating is completed, shut down the dual-target multi-arc system 7, the grid bias device 3, the gas supply system, and the powder heating device 5. Once the vacuum reaction chamber reaches a safe open state, shut down the vacuum pumping system 6 and slowly introduce air or inert gas into the chamber to restore the pressure to atmospheric pressure. Simultaneously, keep the water cooling system running for a period of time to gradually lower the temperature of the chamber and target. Then, open the coating chamber door, remove the removable powder tray 9, collect the coated composite powder, and seal it for later use in cold spraying or other coating preparation processes.

[0059] Example 2:

[0060] This embodiment provides an ultrasonic-assisted TiN deposition method for Al powder based on high-power multi-arc ion plating. Through the synergistic effects of dual-target multi-arc deposition, grid negative bias ion acceleration, and ultrasonic levitation, the Al powder remains dynamically suspended and continuously tumbling during the deposition process, and is uniformly exposed to the high-speed ion current. This results in the formation of a continuous and dense metal shell on the Al powder surface, obtaining a core-shell structured Al@TiN composite powder. The specific operation steps are as follows.

[0061] Step 1, Pre-spreading powder and adjusting powder movement:

[0062] Open the coating chamber and pour the Al powder to be coated into the powder tray 9 according to the set filling amount. Initially spread the powder to form a relatively uniform powder layer at the bottom of the tray. Then, install the powder tray onto the powder-bearing rotating shaft, ensuring reliable contact between the ultrasonic amplitude transformer 13 and the bottom of the tray or the powder-bearing area. Start the ultrasonic generator 14 and the rotary motor 12, causing the tray to rotate and circumferentially tumble the powder. Simultaneously, high-frequency vibration is transmitted to the tray and powder bed through the ultrasonic amplitude transformer 13. The ultrasonic frequency can be selected as 40kHz, the ultrasonic power as 100W, and the amplitude as 10μm; the tray rotation speed can be selected as 10r / min. Adjust the ultrasonic power, amplitude, and tray rotation speed according to the powder particle size, density, and filling amount to ensure the powder is loosely spread, dynamically suspended, and continuously tumbling within the tray, preventing powder accumulation or agglomeration. Once the powder movement reaches the preset requirements, turn off the ultrasonic generator 14 and the rotary motor 12, confirm that there are no abnormalities in the tray installation and sealing parts, close the coating chamber door, and proceed to the subsequent vacuuming and coating processes.

[0063] Step two, cooling, preheating and vacuuming:

[0064] After pre-laying the powder, close the coating chamber door and check the sealing status of the door seals, observation windows, and all pipe interfaces to ensure the vacuum reaction chamber is reliably sealed. Then, turn on the water cooling system to circulate cooling for the chamber, target holder, and related heat-generating components. Start the powder heating device 5 to preheat the tray and the powder to be coated. The heating temperature can be set to 100℃ to improve the powder surface activity and enhance the growth quality and bonding stability of the film during subsequent ion plating. Simultaneously, start the vacuum pumping system 6. First, start the mechanical pump for rough evacuation for 10 minutes to reduce the chamber pressure to below 10 Pa. Once the rough vacuum reaches the high vacuum pump start-up conditions, start the molecular pump for 30 minutes until the vacuum chamber's base vacuum reaches 5 × 10⁻⁶ Pa. -3 Below Pa. After the water cooling, heating and vacuum conditions have all reached the set requirements, proceed to the subsequent arc initiation and deposition coating steps.

[0065] Step 3, Ultrasonic Suspension Assisted Multi-Arc Ion Plating:

[0066] After the vacuum reaction chamber reaches the set background vacuum level, the rotary motor 12 and the ultrasonic auxiliary device are restarted, and the operating parameters determined in step one during pre-powder spreading are invoked to restore the powder to a loose, dynamically suspended, and continuously tumbling state within the tray. The operating parameters, including ultrasonic frequency, ultrasonic power, amplitude, and tray rotation speed, are based on the specific values ​​obtained during the pre-powder spreading stage and are maintained stably throughout the coating process. The powder state is constantly observed through the observation window. If the powder state changes due to temperature, atmosphere, or the deposition process, the ultrasonic power or tray rotation speed can be fine-tuned within a small range to maintain the dynamic suspension and uniform coating state of the powder.

[0067] Subsequently, working gas Ar is introduced into the vacuum reaction chamber at a flow rate of 50 sccm, while reactive gas N2 is introduced at a flow rate of 100 sccm and a pressure of 0.5 Pa. After the gas pressure stabilizes, the grid bias device 3 is activated to apply a negative bias voltage to the grid located above the powder-bearing area. The bias voltage value can be set to -150V. The grid bias device 3 is paired with a grid bias power supply 4. By controlling the ion energy near the powder-bearing area through the negative bias voltage of the grid, the bombardment and deposition of film-forming ions on the powder surface is enhanced.

[0068] After completing the atmosphere and bias voltage adjustments, the dual-target multi-arc system 7 is activated. The target material is Ti. The dual-target multi-arc system 7 is equipped with a high-power, high-stability pulsed arc power supply 8. First, the two targets are ignited to form a stable arc spot on the target surface. The ignition current can be set to 55A, and the ignition stabilization time can be 1 minute. A lower arc current is used in the initial stage of ignition to reduce the impact of unstable ion current on the powder surface deposition quality. After the arc combustion stabilizes, the arc current of the two targets is adjusted to 150A. When using the high-power pulse enhancement mode, the pulse current is 300A, the pulse frequency can be set to 300Hz, and the duty cycle can be set to 20%.

[0069] After the target source stabilizes, the film-forming ion flow continuously enters the powder-bearing area and deposits on the powder surface. During the coating process, the ultrasonic, rotation, gas supply, grid bias, and dual-target multi-arc system operate synchronously, keeping the powder in a dynamic suspension and tumbling state, with different particle surfaces alternately exposed to the deposition ion flow. To avoid powder overheating, agglomeration, or uneven film growth, an intermittent coating method can be used. The total coating time can be set to 180 minutes based on the target shell thickness. Through the above process, a continuous, dense, and relatively uniform Al@TiN shell powder is formed on the powder surface.

[0070] Step 4: Deflating the cavity and removing powder:

[0071] After coating is completed, shut down the dual-target multi-arc system 7, the grid bias device 3, the gas supply system, and the powder heating device 5. Once the vacuum reaction chamber reaches a safe open state, shut down the vacuum pumping system 6 and slowly introduce air or inert gas into the chamber to restore the pressure to atmospheric pressure. Simultaneously, keep the water cooling system running for a period of time to gradually lower the temperature of the chamber and target. Then, open the coating chamber door, remove the removable powder tray 9, collect the coated composite powder, and seal it for later use in cold spraying or other coating preparation processes.

[0072] It should be noted that the present invention uses the deposition of Ti and TiN films on the surface of Al powder as a specific embodiment, but is not limited to Al powder material. All kinds of powder substrates, such as metal powder, inorganic powder, and non-metal powder, can be surface coated and modified using the coating process and structural scheme described in the present invention, and all fall within the protection scope of the present invention.

[0073] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A powder ultrasonic-assisted coating device based on high-power multi-arc ion plating, characterized in that, include: The coating chamber forms a vacuum reaction chamber inside, which is used to contain the powder to be coated and provide a reaction space for powder coating. The vacuum pumping system (6) is connected to the vacuum reaction chamber through a pumping pipe and is used to establish and maintain the vacuum environment required for the coating process. A gas supply system is used to introduce working gas and reaction gas into the vacuum reaction chamber and is connected to the vacuum reaction chamber through a gas supply pipeline (1); The dual-target multi-arc system (7) includes two targets symmetrically arranged at the top of the vacuum reaction chamber. High-power pulse-enhanced multi-arc ion plating is used to achieve powder film deposition. A grid bias device (3) is disposed in the vacuum reaction chamber and located above the powder carrying area, and is used to apply a negative bias to the area above the powder. A powder tray (9) is set inside the vacuum reaction chamber to hold the powder to be plated. The powder tray (9) is detachable and connected to the rotating shaft and heating element to receive the vibration transmitted by the ultrasonic auxiliary device. The powder heating device (5) is set inside the vacuum reaction chamber and is used to control the temperature of the powder to be plated. The ultrasonic auxiliary device includes an ultrasonic generator (14) and an ultrasonic amplitude transformer (13), wherein the ultrasonic amplitude transformer (13) acts on the powder bearing area to apply high-frequency vibration to the powder; The powder driving mechanism includes a rotary motor (12) and a bevel gear transmission assembly (11) for driving the powder tray (9) to rotate continuously during the coating process, so that the powder remains in motion. The water cooling system includes a cooling water inlet pipe (2) and a cooling water outlet pipe (10) for circulating cooling of the coating chamber and the target.

2. The ultrasonic-assisted powder coating device based on high-power multi-arc ion plating according to claim 1, characterized in that: The ultrasonic auxiliary device works in conjunction with the powder driving mechanism to keep the powder to be coated in a state of dynamic suspension, continuous turning and uniform spreading in the powder tray (9), so that the powder particles are uniformly exposed to the film-forming ion flow, thereby improving the coating uniformity of the powder surface film.

3. The ultrasonic-assisted powder coating device based on high-power multi-arc ion plating according to claim 1, characterized in that: The powder to be coated is in a dynamic suspension state during the coating process, making it difficult to directly apply a stable bias voltage, which will result in a weak film adhesion. The grid bias device (3) is set above the powder bearing area to form a negative bias electric field and accelerate the metal ions entering the area to form the film, thereby improving the density, adhesion strength and deposition uniformity of the film on the powder surface.

4. A powder ultrasonic-assisted coating method based on high-power multi-arc ion plating, characterized in that, Includes the following steps: Step 1, Pre-spreading powder and adjusting powder movement: Add the powder to be plated into the powder tray (9), start the ultrasonic auxiliary device and the powder driving mechanism, adjust the ultrasonic parameters and rotation parameters, so that the powder to be plated forms a loose, flat, dynamic, and continuously tumbling state in the tray. After the requirements are met, turn off the ultrasonic generator (14) and the rotary motor (12). Step two, cooling, preheating and vacuuming: Close the coating chamber, turn on the water cooling system, powder heating device (5) and vacuum pumping system (6) to evacuate the vacuum reaction chamber and preheat the powder to be coated so that the vacuum reaction chamber reaches the set vacuum level. Step 3, Ultrasonic Suspension Assisted Multi-Arc Ion Plating: After the vacuum reaction chamber reaches the set vacuum level, the ultrasonic auxiliary device and rotary motor (12) are restarted according to the parameters determined in the pre-powdering stage, so that the powder is kept in a dynamic suspension and continuously tumbling uniform coating state; then Ar gas is introduced, the grid bias device (3) is turned on to accelerate the film-forming ions, and the dual-target multi-arc system (7) is started to start the arc and stabilize the deposition, so that the film-forming ions are deposited on the powder surface to form a continuous, dense and uniform film layer. Step 4: Deflating the cavity and removing powder: After the coating is completed, shut down the dual-target multi-arc system (7), grid bias device (3), gas supply system, powder heating device (5) and vacuum pumping system (6), wait for the cavity to cool down and return to normal pressure, open the coating chamber and take out the coated composite powder.

5. The method for ultrasonic-assisted powder coating based on high-power multi-arc ion plating according to claim 4, characterized in that: In step one, the ultrasonic frequency of the ultrasonic auxiliary device is 20-40kHz, the ultrasonic power is 100-800W, and the amplitude is 5-50μm; the rotation speed of the powder tray (9) is 5-60r / min. By adjusting the ultrasonic frequency, ultrasonic power, amplitude, and tray rotation speed, the powder to be coated is made to form a loose, flat, dynamically suspended, and continuously turning state in the tray.

6. The method for ultrasonic-assisted powder coating based on high-power multi-arc ion plating according to claim 4, characterized in that: In step two, the powder heating device (5) preheats the powder to be plated at a temperature of 100-300°C to improve the surface activity of the powder and improve the growth quality and bonding stability of the film layer in the subsequent ion plating process.

7. The method for ultrasonic-assisted powder coating based on high-power multi-arc ion plating according to claim 4, characterized in that: In step two, the vacuum pumping system (6) pumps the vacuum reaction chamber to a vacuum degree of 5x10 -3 Pa or below to meet the process requirements of subsequent ventilation and double-target multi-arc ion plating deposition.

8. The method for ultrasonic-assisted powder coating based on high-power multi-arc ion plating according to claim 4, characterized in that: In step three, Ar gas is introduced into the vacuum reaction chamber at a flow rate of 20–80 sccm to maintain the working pressure in the vacuum reaction chamber at 0.2–0.8 Pa. If a nitride film is to be prepared, N2 gas is introduced simultaneously at a flow rate of 5–100 sccm. By adjusting the flow ratio of Ar to N2, the composition and growth state of the deposited film are controlled.

9. The method for ultrasonic-assisted powder coating based on high-power multi-arc ion plating according to claim 4, characterized in that: In step three, the negative bias voltage applied by the grid bias device (3) is -50 to -300V, and the magnitude of the negative bias voltage is adjusted according to the target material and the type of target film.

10. The method for ultrasonic-assisted powder coating based on high-power multi-arc ion plating according to claim 4, characterized in that: In step three, the dual-target multi-arc system (7) is started. First, the arc is started on the two targets with an arc-starting current of 55A. After the arc forms a stable arc spot on the target surface, the arc current of the two targets is adjusted to 60-150A. When the high-power pulse enhancement mode is used, the pulse current is 80-500A, the pulse frequency is 0.1-5kHz, and the duty cycle is 10%-80%.

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