A multifunctional device for realizing multi-stage particle deposition and collection in thermal spraying

Abstract

The present invention discloses a multifunctional device for realizing multi-stage particle deposition and collection in thermal spraying, and belongs to the field of thermal spraying technology. The device comprises a tank body, a rotating shaft, a front baffle, a rear baffle and a rotating shielding mechanism; wherein: a front baffle and a rear baffle are respectively arranged at both ends of the tank body, an inlet module is installed on the front baffle, and the spraying flame flows into the tank body through the inlet module; a rotating shaft is installed on the rear baffle, one end of the rotating shaft passes through the rear baffle and enters the tank body, and a sample is installed at the end of the rotating shaft entering the tank body; the rotating shielding mechanism is arranged on the outer side of the front baffle, and a window is opened on the rotating shielding mechanism, and the position of the window corresponds to the position of the inlet module. The device can adjust parameters such as spraying distance, air intake volume, particle inlet size, etc., and can be conveniently matched with thermal spraying equipment. The device is suitable for research and detection work in the fields of cold spraying, thermal spraying, etc.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal spraying, and particularly relates to a multifunctional device for realizing multi-stage particle deposition and collection in thermal spraying. Background Art

[0002] Thermal spraying technology is to rapidly heat the spraying material to the molten or semi-molten state by using a heat source. At the same time, under the action of the flame flow, the molten or semi-molten particles are sprayed and deposited on the surface of the pretreated substrate at a relatively high speed to form flattened particles. A large number of particles continuously accumulate on the surface of the substrate to form a coating. The raw materials used in thermal spraying technology are generally powders or wires, and there are many types of heat sources, such as electric arcs, plasma arcs, fuel combustion, etc. According to the different heat sources or technologies used, there are various thermal spraying technologies such as flame spraying, plasma spraying, explosion spraying, supersonic flame spraying, supersonic plasma spraying, etc.

[0003] Thermal spraying technology creates a special working surface on the surface of treated ordinary materials (generally metals), so that it can achieve a series of functions such as anti-corrosion, wear resistance, friction reduction, high temperature resistance, oxidation resistance, heat insulation, insulation, conductivity, microwave radiation protection, etc., so as to achieve the purpose of improving the surface and application performance of materials and saving energy materials. This special working surface is called a coating. The process of manufacturing the coating uses fuel combustion to generate heat, so the working method of manufacturing the coating is called thermal spraying. Thermal spraying technology is one of the important components of surface engineering technology and an indispensable processing technology in modern industry.

[0004] The core of thermal spraying technology is the spraying process parameters, and the performance of the prepared coating often depends on the coating material and the thermal spraying process. The important technical parameters of thermal spraying technology are: powder feeding rate (wire feeding rate), heat source temperature (power), spraying distance, spray gun moving rate, spraying angle. Multiple parameters need to be determined and optimized in the thermal spraying process, which will inevitably generate a large number of orthogonal tests, bringing a great deal of workload to the process optimization work.

[0005] From the perspective of the coating formation mechanism, the coating formation process is a process in which a large number of molten or semi-molten particles collide, deform, cool and accumulate on the substrate surface. Therefore, the characteristics of the molten particles, such as temperature, speed, melting state, composition, etc., have become the key factors affecting the coating performance. Starting from the characteristics of the molten particles can guide the improvement of the macroscopic thermal spraying process at the microscopic level. In order to reduce the large amount of work brought by orthogonal tests, it is necessary to analyze the characteristics of the molten or semi-molten particles during the flight process in the spraying process, such as surface state, oxygen content, melting state, chemical composition (burn loss), etc. Based on this, find out the influence law of the thermal spraying process on the characteristics of the molten or semi-molten particles, so as to better obtain the optimal spraying process.

[0006] Currently, there are some methods to obtain molten particles, mainly including water quenching method, air cooling method and liquid nitrogen cooling method. When using the water quenching method, some spraying materials will react with water at high temperatures (such as active metals, etc.), and the powder collected at this time is not in the state during the actual thermal spraying process; while when using the liquid nitrogen cooling method, due to the extremely low temperature of liquid nitrogen, when the high-temperature molten particles encounter liquid nitrogen, they solidify rapidly, and the state during particle flight, such as oxygen content, can be maintained to the greatest extent.

[0007] To study the coating formation mechanism and evaluate the deposition effect of molten particles, the research on the single-particle deposition point, which is the most basic unit of the coating, is particularly important. To observe the single-particle deposition point, methods such as reducing the powder delivery amount and searching at the edge of the sample are usually used, but this is not sufficient to obtain the deposition state under the actual spraying process. For this reason, the present invention realizes the acquisition of single-particle and multi-particle deposition samples under various spraying processes by adopting a particle separation system (composed of a rotating baffle, an inlet module, and a rotating sample), which provides accurate samples for the research of thermal spraying coatings. Summary of the Invention

[0008] The purpose of the present invention is to provide a multi-functional device for realizing multi-stage particle deposition and collection in thermal spraying. This device can obtain single-particle and multi-particle deposition samples during the thermal spraying process, providing detailed and accurate samples for the research of the spraying process and mechanism research; it can also capture the flying molten and semi-molten particles in real time during the thermal spraying process, quickly cool and collect them. By studying and analyzing the obtained powder, it is used to guide the optimization of the thermal spraying process, and finally obtain high-performance coatings.

[0009] To achieve the above purpose, the technical solutions adopted by the present invention are as follows:

[0010] A multi-functional device for realizing multi-stage particle deposition and collection in thermal spraying, including a tank body, a rotating shaft, a front baffle, a rear baffle and a rotating shielding mechanism; wherein: the front baffle and the rear baffle are respectively arranged at both ends of the tank body, an inlet module is installed on the front baffle, and the spraying flame flow enters the tank body through the inlet module; a rotating shaft is installed on the rear baffle, one end of the rotating shaft passes through the rear baffle and enters the tank body, and a sample plate is installed at the end of the rotating shaft entering the tank body; the rotating shielding mechanism is arranged outside the front baffle, and a window is opened on the rotating shielding mechanism, and the position of the window corresponds to the position of the inlet module.

[0011] An air inlet pipe is provided at the position of the tank body (collection tank) close to the front baffle below, and an exhaust pipe is provided at the position of the tank body close to the rear baffle below; the air inlet pipe and the exhaust pipe are used for the input and output of inert gas; the front baffle, the rear baffle and the tank body are detachably connected to facilitate the cleaning of the tank body and the collection of the powder in the tank.

[0012] The front baffle and the rear baffle are fixed to the tank body by hook bolts, and there is a high-temperature resistant rubber ring in the middle to ensure the airtightness of the tank body; the front baffle, the rear baffle and the tank body are all made of stainless steel, and all inner surfaces are polished to avoid the influence of impurities such as rust on the results and also avoid the adhesion of molten particles to the inner wall.

[0013] A liquid nitrogen tank is provided at the upper part of the tank body. A pressurized gas pipe is provided at the top of the liquid nitrogen tank. The bottom of the liquid nitrogen tank is sequentially connected with a valve and a nozzle, and the nozzle extends into the tank body; the liquid nitrogen in the liquid nitrogen tank is sprayed into the tank body from the nozzle to form a "liquid nitrogen curtain" to quickly cool the molten particles in the tank body; this not only ensures that the molten particles can contact with the liquid nitrogen to achieve rapid solidification and cooling, but also saves liquid nitrogen and reduces the test cost.

[0014] A hole Ⅰ for passing through the rotating shaft is opened on the rear baffle. This hole Ⅰ deviates from the center of the rear baffle, so that the axis of the rotating shaft deviates from the axis of the tank body. Then when the rotating shaft rotates, it drives the template to rotate around the axis of the rotating shaft; the rotation of the rotating shaft is powered by a rotating shaft motor.

[0015] The rotating shaft is a telescopic structure, and the length entering the tank body is adjustable; there are scales marked on the rotating shaft to facilitate reading the size of the telescopic amount; the front end of the rotating shaft has a clamping structure for installing the template; the rotation speed of the rotating shaft is adjustable.

[0016] The inlet module is a single-layer stainless steel circular plate with a thickness of 1 - 5 mm and a diameter of 60 mm. The inlet module is fixed to the front baffle with screws, which is convenient for replacement; the inlet module is designed as a single-hole type or a multi-hole type. The aperture of the single-hole type inlet module is 0.5 - 10 mm, which is determined according to the actual research needs; a plurality of small round holes are opened on the multi-hole type inlet module, and the arrangement of each round hole is a rectangular array of (5 - 8) × (5 - 8), and the diameter of the round hole is 0.1 - 0.5 mm.

[0017] A stepped round hole is opened in the center of the front baffle. The diameter of the inlet module matches the stepped round hole on the front baffle. The inlet template is placed behind the stepped round hole on the front baffle and then fixed by screws or pressing pieces.

[0018] The rotary shielding mechanism includes a rotary shielding plate, a baffle support and a rotary motor; the rotary shielding plate is installed between the center of the front baffle and the spray gun (for spraying the spraying flame flow). The rotary shielding plate is a circular metal thin plate. There is a window with a diameter of 100 mm near the edge of the rotary shielding plate. The molten particles pass through this window and are sprayed into the tank body through the inlet template; the rotation power of the rotary shielding plate is provided by the rotary motor, and the rotary shielding plate is supported by the baffle support; by adjusting the rotation speed of the rotary shielding plate, the model of the inlet module (aperture and number of holes) and the rotation speed of the rotating shaft, the preparation of single-particle deposition or multi-particle deposition samples can be realized.

[0019] The tank body is fixed on the bracket with bolts. The bracket needs to be stable and have lockable wheels at the bottom, which can be moved in any direction. The bracket is made of aluminum alloy or steel, and flammable materials such as plastic and wood are not allowed. A handle can be installed on the tank body.

[0020] The advantages and beneficial effects of the present invention are as follows:

[0021] 1. The most basic unit of coating formation is a single particle deposition point. The study of single particle and multiple particle deposition plays an important role in studying the mechanism of thermal spraying. The device invented by this valve for realizing single particle and multiple particle deposition of thermal spraying and collecting molten particles in the thermal spraying flame can obtain single particle deposition point samples and multiple particle deposition point samples, providing direct samples for direct observation and research of thermal spraying particle deposition.

[0022] 2. The study of the characteristics of molten and semi-molten particles is an important part of thermal spraying research, but there is no commercial molding equipment for molten particle capture devices. In response to this dilemma, the present invention has developed a device for realizing thermal spraying single particle and multi-particle deposition and collecting molten particles in the thermal spraying flame, which provides a sample acquisition method for the study of the characteristics of molten and semi-molten particles, which are key parameters in the thermal spraying process.

[0023] 3. The device of the present invention uses liquid nitrogen spraying to rapidly cool down and solidify the molten particles, which not only ensures that the molten particles can contact with liquid nitrogen to achieve rapid solidification and cooling, but also saves liquid nitrogen and reduces the test cost;

[0024] 4. The device of the present invention can achieve the preparation of single-particle and multi-particle deposition point samples by adjusting the rotation speed of the rotating shielding plate, the rotating shaft, etc. and cooperating with different inlet modules.

[0025] 5. The device of the present invention can effectively capture molten and semi-molten particles, and can collect different quantities of molten particles by replacing different inlet modules.

[0026] 6. The inlet module used in the device of the present invention has a simple structure, small size, low cost and easy replacement. There is no economic and time cost pressure for large-scale testing.

[0027] 7. The device of the present invention is suitable for various thermal spraying such as flame spraying, supersonic flame spraying, plasma spraying, etc. Brief Description of the Figures

[0028] Figure 1 This is a schematic diagram of the structure of the device for collecting molten particles in the thermal spraying flame flow of the present invention.

[0029] Figure 2 This is a schematic diagram of the connection structure between the exhaust pipe and the tank body of the present invention.

[0030] Figure 3Schematic diagram of the air inlet pipe structure near the front baffle of the tank body of the present invention.

[0031] Figure 4 Schematic diagram of the rear baffle structure of the present invention.

[0032] Figure 5 Schematic diagram of the front baffle structure of the present invention.

[0033] Figure 6 Schematic diagram of the inlet module structure of the present invention.

[0034] Figure 7 Schematic diagram of the rotating baffle structure of the present invention.

[0035] Figure 8 SEM photograph of the thermal spraying powder collected in Example 2.

[0036] Figure 9 SEM photograph of the thermal spraying powder collected in Example 4.

[0037] Figure 10 Thermal spraying multi-particle deposition photograph collected in Example 3.

[0038] Figure 11 Thermal spraying single-particle deposition photograph collected in Example 1; wherein: (a), (b), and (c) are photographs of three of the particles.

[0039] In the figure: 1 - tank body; 2 - rear baffle; 301 - template; 302 - rotating shaft motor; 303 - rotating shaft; 4 - exhaust pipe; 5 - bracket; 6 - front baffle; 601 - stepped hole; 602 - paddle; 603 - front baffle rubber ring groove; 701 - rotating motor; 702 - rotating baffle; 703 - window; 704 - baffle bracket; 8 - inlet module; 801 - round hole; 802 - inlet module rubber ring groove; 9 - liquid nitrogen tank; 901 - pressurized air pipe; 902 - valve; 903 - liquid nitrogen nozzle; 10 - front baffle; 11 - air inlet pipe. Detailed implementation manners

[0040] To further understand the present invention, the following describes the present invention in combination with the accompanying drawings and embodiments. However, the embodiments are only for further elaborating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0041] To study the particle deposition mechanism during the thermal spraying process, as well as the characteristics of molten and semi-molten particles, the present invention provides a device for realizing the deposition of multi-stage particles (single particles, multi-particles) in thermal spraying and collecting the molten particles in the thermal spraying flame flow. It can be used for the study of thermal spraying mechanisms and the parameter optimization and debugging of various thermal spraying processes. Its structure is as Figures 1-7As shown in the figure. The device includes a tank body 1, a rear baffle 2, a template 301, a rotating shaft 303, a bracket 5, a front baffle 6, a rotating shielding baffle 702, an inlet module 8, a liquid nitrogen tank 9, a front shielding baffle 10, etc.

[0042] As Figure 1 , the tank body 1 is made of stainless steel, with a diameter of 100 mm to 300 mm, polished inside, and has flange rings on both sides to connect to the front baffle 6 and the rear baffle 2 respectively. The front baffle and the rear baffle are made of stainless steel and polished on the inner side. The tank body is fixed to the bracket 5 by screws. A stainless steel inlet pipe 11 is provided near the front baffle at the front of the tank body 1, and the stainless steel inlet pipe 11 is welded to the tank body 1; the stainless steel inlet pipe 11 can be connected to an inert gas source (such as a gas cylinder) by a flexible gas pipe. A liquid nitrogen tank 9 is also provided near the front baffle above the tank body 1, and an exhaust pipe 4 is provided near the rear baffle below the tank body 1; the rear baffle 2, the front baffle 6, and the liquid nitrogen tank 9 are all connected to the tank body 1 by hook bolts or welding; rubber gaskets are provided at the connections between the tank body 1 and the exhaust pipe 4, the rear baffle 2, and the front baffle 6 to prevent air leakage. The front shielding baffle 10 is made of stainless steel or steel and is fixed to the tank body 1 by bolts to shield the liquid nitrogen tank 9 and prevent the spraying flame flow from directly acting on the liquid nitrogen tank 9.

[0043] As Figure 2 As shown in the figure, the exhaust pipe 4 is connected to the exhaust port at the bottom end of the tail of the tank body in a quick-release manner. The exhaust pipe 4 is in the shape of a "check mark", with a pipe diameter of 30 - 60 mm, which is conducive to the smooth discharge of inert gas and leaving the powder entrained in the gas at the bend of the pipeline.

[0044] As Figure 3 As shown in the figure, a hole Ⅰ for installing the rotating shaft is opened on the rear baffle 2, and this hole Ⅰ deviates from the center of the rear baffle, so that the axis of the rotating shaft deviates from the axis of the tank body. When the rotating shaft rotates, it drives the template to rotate around the axis of the rotating shaft; the rotation of the rotating shaft is powered by a rotating shaft motor. Further, the rotating shaft is a telescopic structure. One end of the rotating shaft 303 enters the tank body 1 through the rear baffle. The rotating shaft 303 is connected to the tank body by hook bolts or fastening bolts, and there is a high-temperature resistant rubber gasket in the middle to maintain sealing. The rotating shaft 303 is marked with scales, which can facilitate reading the size of the telescopic amount; and the length entering the tank body 1 can be adjusted; a template 301 is installed at the front end (the end extending into the tank body) of the rotating shaft 303. The rotating shaft 303 is rotated by a rotating shaft motor 302, and the rotation speed is stable and adjustable.

[0045] As Figure 4As shown in the figure, the liquid nitrogen tank 9 is designed with double-layer stainless steel. The bottom of the liquid nitrogen tank 9 is connected to the valve 902 by bolts, and there is a sealing rubber ring in the middle. This valve 902 is an electric or pneumatic valve; the top of the liquid nitrogen tank 9 is designed with a pressurized gas pipe 901, and the pressurized gas pipe 901 is connected to the liquid nitrogen tank 9 by threads, and there is a sealing rubber ring in the middle; the bottom valve 902 of the liquid nitrogen tank 9 is an electric or pneumatic valve; the valve 902 is connected to the liquid nitrogen nozzle 903, and the valve and the liquid nitrogen nozzle 903 are connected by quick release, and there is a sealing rubber ring in the middle; the liquid nitrogen nozzle 903 is welded to the tank body 1, and the liquid nitrogen can be sprayed into the tank body in a specified direction.

[0046] As Figure 5 shown in the figure, the front baffle 6 is a circular stainless steel plate, with a stepped hole 601 opened in the middle, and 4 pieces of flappers 602 for fixing the inlet module 8 are evenly arranged near the inner edge, and there is a front baffle rubber ring groove 603 for placing the rubber ring near the outer edge.

[0047] As Figure 6 shown in the figure, the inlet module 8 is a single-layer stainless steel circular plate, and its diameter matches the stepped circular hole of the front baffle; the outer edge of the inlet module 8 is set in a stepped shape, with an inlet module rubber ring groove 802 on the outer ring, and one or more circular holes 801 are evenly distributed in the center. The outer edge of the inlet module 8 coincides with the stepped hole on the front baffle 6. When in use, the inlet module 8 is placed in the stepped hole 601 of the front baffle 6 and fixed with the flapper 602 or screws, etc.

[0048] As Figure 7 shown in the figure, the rotating baffle 702 is a circular metal plate, with a window 703 with a diameter of 100 mm opened near the edge for the molten particles to pass through. When the window 703 is at the highest position, the center height thereof is the same as the center height of the inlet module. The adjustable speed rotation of the rotating baffle can be realized by using the rotating motor 701, and the baffle bracket 704 is used as a support.

[0049] The bracket 5 is made of aluminum alloy or other materials (such as steel), with a stable structure, can adjust the height, and there are multiple lockable universal wheels at the bottom, which is convenient for moving and fixing. The bracket should be as stable as possible to avoid tipping during the process of collecting powder by thermal spraying. For the convenience of moving. The tank body is fixed on the bracket by bolts.

[0050] All connections between the tank body and each part of the present invention are designed to be detachable for easy cleaning. There is a total of 1 tank body inlet pipe 11 and 1 pressurized gas pipe 901. A hose can be used to connect to an inert gas cylinder or pipeline, and the intake pressure can be adjusted by using the pressure reducing valve equipped at the gas source.

[0051] In the single-particle deposition sample preparation experiment, to achieve single-particle deposition, the present invention shields almost all the sprayed particles by adjusting the rotation speed of the baffle, adjusting the rotation speed of the rotating shaft, and replacing the inlet modules of different models, so as to realize the preparation of single-particle deposition samples. Similarly, these parameters can also be adjusted to achieve multi-particle deposition.

[0052] In the powder collection experiment, the amount of powder to be collected varies. To meet the experimental requirements, the inlet module has two designs: single-hole type and multi-hole integral type. The aperture of the single-hole type inlet module can be 0.5 - 10 mm, depending on the actual needs; the multi-hole type inlet module can be composed of multiple small round holes, and the hole array is a rectangular array of 5 - 8 × 5 - 8, and the diameter of the round hole is 0.1 mm - 0.5 mm. The inlet module is designed for quick replacement. When the small hole is blocked, it can be replaced immediately.

[0053] Example 1:

[0054] After all components are installed, select the single-hole type structure for the inlet module with an aperture of 0.1 mm. Install the inlet module on the front baffle and fix it with screws and paddles. Push the device to the set position, rotate the lifting screw on the rotating bracket, adjust the center height of the inlet module to 1.2 meters, and start the bracket locking device. Open the rear baffle, sandblast the sample (template), and install it at the sample clamp of the rotating shaft. Install the rear baffle, adjust the length of the rotating shaft extending into the tank to the scale of 400 mm (at this time, the spraying distance is 400 mm), and fix the rotating shaft to the rotating motor. Adjust the position of the baffle so that the baffle window can face the center of the inlet module during rotation. Adjust the movement program of the thermal spraying gun so that when the gun moves, the nozzle passes through the center position of the inlet module and the nozzle is 200 mm away from the inlet module. Close the liquid nitrogen valve. Connect the inlet pipe to the high-purity argon gas cylinder and set the gas pressure to 0.3 MPa. Open the inlet pipe valve, fill the tank with argon, and continue until the end of the experiment.

[0055] Start the thermal spraying equipment at another position. After the spraying state is stable, turn on the rotating switch of the rotating shaft, set the rotation speed to 15 revolutions per second, turn on the rotating switch of the baffle, set the rotation speed to 10 revolutions per second, set the spraying parameters according to the spraying process, such as powder feeding rate, gas flow rate, gun movement rate, etc. Start the spraying program. After the gun passes through the position of the inlet module once, the gun stops moving. Turn off the thermal spraying system, turn off the inlet pipe valve, stop the rotation of the baffle, and stop the rotation of the rotating shaft. The experiment ends, and a single-particle deposition sample is obtained. Take out the sample. The thermal spraying single-particle deposition photo collected in this example is as Figure 11 .

[0056] Example 2:

[0057] After all components are installed, the inlet module is a single-hole structure with a hole diameter of 0.5mm. The inlet module is installed on the front baffle and fixed with screws and paddles. Push the device to the set position, turn the lifting screw on the bracket, adjust the center height of the inlet module to 1.2 meters, and start the bracket locking device. Adjust the position of the rotating baffle so that the baffle window faces the center of the inlet module. Adjust the position of the thermal spray gun so that the nozzle faces the center of the inlet module. The position of the spray gun is defined as the powder collection position, and the position of the spray gun is recorded. Close the liquid nitrogen valve, add liquid nitrogen to the liquid nitrogen tank, connect the pressurized gas pipe to the nitrogen cylinder, set the gas pressure to 0.5MPa, connect the air inlet pipe to the high-purity argon cylinder, and set the gas pressure to 0.3MPa. Open the air inlet valve, fill the tank with argon, and continue until the end of the test.

[0058] Start the thermal spraying equipment at another location. After the spraying state is stable, open the valve of the liquid nitrogen tank, open the valve of the pressurized air pipe, quickly move the spray gun to the powder collection position, spray at the powder collection position for 10 seconds, quickly move the spray gun away, and then turn off the thermal spraying system, close the air inlet valve, and close the pressurized air pipe valve.

[0059] Open the tank to collect the powder. The powder is mainly in the lower part of the tank and the bend of the exhaust pipe. After the powder is collected, it is vacuum packed and marked for analysis. Clean the inside of the tank and the inner wall of the exhaust pipe to avoid contamination in the next collection test. At this point, the powder collection is completed. The SEM photos of the thermal spray powder collected in this example are as follows Figure 8 .

[0060] Example 3:

[0061] After all parts are installed, the inlet module is selected as a single-hole structure with a hole diameter of 0.3mm. The inlet module is installed on the front baffle and fixed with screws and paddles. Push the device to the set position, turn the lifting screw on the bracket, adjust the center height of the inlet module to 1.2 meters, and start the bracket locking device. Open the rear baffle, sandblast the sample, install it at the sample clamp of the shaft, install the rear baffle, adjust the length of the shaft extending into the tank to 350mm on the scale (at this time, the spraying distance is 350mm), and fix the shaft to the rotating motor. Adjust the position of the baffle so that the baffle window can face the center of the inlet module when rotating. Adjust the movement program of the thermal spray gun so that when the gun moves, the gun mouth passes through the center of the inlet module and the gun mouth is 200mm away from the inlet module. Close the liquid nitrogen valve. Connect the air inlet pipe to the high-purity argon gas cylinder and set the gas pressure to 0.3MPa. Open the air inlet pipe valve, fill the tank with argon gas, and continue until the end of the test.

[0062] Start the thermal spraying equipment at another location. After the spraying state is stable, turn on the shaft rotation switch and set the speed to 5 rpm. Turn on the baffle rotation switch and set the speed to 10 rpm. Set the spraying parameters according to the spraying process, such as powder feeding rate, gas flow rate, spray gun movement rate, etc. Start the spraying program. After the spray gun passes the inlet module position once, stop the movement of the spray gun, turn off the thermal spraying system, close the air intake valve, stop the baffle rotation, stop the shaft rotation, and the test is over to obtain a multi-particle deposition sample. Take out the sample. The photos of thermal spray multi-particle deposition collected in this embodiment are as follows Figure 10 .

[0063] Example 4:

[0064] After all components are installed, the inlet module is selected with a porous structure, with a hole array of 5X5, each hole diameter of 0.2mm, and a hole spacing of 3mm. Install the inlet module on the front baffle and fix it with screws and paddles. Push the device to the set position, turn the lifting screw on the bracket, adjust the center height of the inlet module to 1.2 meters, and start the bracket locking device. Adjust the position of the rotating baffle so that the baffle window faces the center of the inlet module. Adjust the position of the thermal spray gun so that the gun mouth faces the center of the inlet module. The position of the gun is defined as the powder collection position, and the gun position is recorded. Close the liquid nitrogen valve, add liquid nitrogen to the liquid nitrogen tank, connect the pressurized gas pipe to the nitrogen cylinder, set the gas pressure to 0.5MPa, connect the air inlet pipe to the high-purity argon cylinder, and set the gas pressure to 0.3MPa. Open the air inlet pipe valve, fill the tank with argon, and continue until the end of the test.

[0065] Start the thermal spraying equipment at another location. After the spraying state is stable, open the valve of the liquid nitrogen tank, open the valve of the pressurized air pipe, quickly move the spray gun to the powder collection position, spray at the powder collection position for 10 seconds, quickly move the spray gun away, and then turn off the thermal spraying system, close the air inlet valve, and close the pressurized air pipe valve.

[0066] Open the tank to collect the powder. The powder is mainly in the lower part of the tank and the bend of the exhaust pipe. After the powder is collected, it is vacuum packed and marked for analysis. Clean the inside of the tank and the inner wall of the exhaust pipe to avoid contamination in the next collection test. At this point, the powder collection is completed. The SEM photos of the thermal spray powder collected in this example are as follows Figure 9 .

Claims

1. A multifunctional device for realizing multi-stage particle deposition and collection in thermal spraying, characterized in that: The device comprises a tank body, a rotating shaft, a front baffle, a rear baffle and a rotating shielding mechanism; wherein: the front baffle and the rear baffle are respectively arranged at both ends of the tank body, an inlet module is installed on the front baffle, and the spray flame flow enters the tank body through the inlet module; the rotating shaft is installed on the rear baffle, one end of the rotating shaft passes through the rear baffle and enters the tank body, and a sample is installed on the end of the rotating shaft entering the tank body; the rotating shielding mechanism is arranged on the outer side of the front baffle, and a window is opened on the rotating shielding mechanism, and the position of the window corresponds to the position of the inlet module; The inlet module is a single-layer stainless steel circular plate with a thickness of 1-5 mm and a diameter of 60 mm. The inlet module is fixed to the front baffle with screws, which is easy to replace. The inlet module is designed to be single-hole or multi-hole. The aperture of the single-hole inlet module is 0.5-10 mm, depending on the actual needs of the research. The multi-hole inlet module has multiple small circular holes, and the arrangement of the circular holes is a rectangular array of (5-8) × (5-8), and the diameter of the circular holes is 0.1-0.5 mm. The rotating shielding mechanism comprises a rotating shielding plate, a shielding plate bracket and a rotating motor; the rotating shielding plate is installed between the center of the front shielding plate and the spray gun, the rotating shielding plate is a circular metal sheet, and a window with a diameter of 100 mm is provided near the edge of the rotating shielding plate, and the molten particles pass through the window and are sprayed into the tank body through the inlet template; the rotating power of the rotating shielding plate is provided by the rotating motor, and the rotating shielding plate is supported by the shielding plate bracket; by adjusting the rotating speed of the rotating shielding plate, the inlet module model and the rotating shaft speed, the spraying single particle deposition or multi-particle deposition sample preparation can be realized.

2. The multifunctional device for realizing multi-stage particle deposition and collection in thermal spraying according to claim 1, characterized in that: An air inlet pipe is provided below the tank body near the front baffle, and an exhaust pipe is provided below the tank body near the rear baffle; the air inlet pipe and the exhaust pipe are used for input and output of inert gas; the front baffle, the rear baffle and the tank body are detachably connected to facilitate cleaning of the tank body and collection of powder in the tank.

3. The multifunctional device for realizing multi-stage particle deposition and collection in thermal spraying according to claim 2, characterized in that: The front baffle and the rear baffle are fixed to the tank body with hook bolts, and a high-temperature resistant rubber ring is arranged in the middle to ensure the airtightness of the tank body; the front baffle, the rear baffle and the tank body are all made of stainless steel, and all inner surfaces are polished to avoid the influence of impurities such as rust on the results, and to avoid the adhesion of molten particles to the inner wall.

4. The multifunctional device for realizing multi-stage particle deposition and collection in thermal spraying according to claim 1, characterized in that: A liquid nitrogen tank is provided on the upper part of the tank body, a pressurized air pipe is provided on the top of the liquid nitrogen tank, a valve and a nozzle are connected to the bottom of the liquid nitrogen tank in sequence, and the nozzle extends into the tank body; liquid nitrogen in the liquid nitrogen tank is sprayed into the tank body from the nozzle to form a "liquid nitrogen curtain" to quickly cool the molten particles in the tank body; this ensures that the molten particles can contact with liquid nitrogen to achieve rapid solidification and cooling, and also saves liquid nitrogen and reduces the test cost.

5. The multifunctional device for realizing multi-stage particle deposition and collection in thermal spraying according to claim 1, characterized in that: The rear baffle is provided with a hole I for passing the rotating shaft, and the hole I deviates from the center of the rear baffle so that the axis of the rotating shaft deviates from the axis of the tank body. When the rotating shaft rotates, the sample is driven to rotate around the axis of the rotating shaft; the rotation of the rotating shaft is powered by the rotating shaft motor.

6. The multifunctional device for realizing multi-stage particle deposition and collection in thermal spraying according to claim 5, characterized in that: The rotating shaft is a telescopic structure, and the length entering the tank body is adjustable; the rotating shaft is marked with scales, which can easily read the amount of telescopic movement; the front end of the rotating shaft has a clamping structure for installing the sample; the rotating shaft speed is adjustable.

7. The multifunctional device for realizing multi-stage particle deposition and collection in thermal spraying according to claim 1, characterized in that: A stepped circular hole is opened in the center of the front baffle, and the diameter of the inlet module matches the stepped circular hole on the front baffle. The inlet template is placed in the stepped circular hole of the front baffle and then fixed by screws or pressing sheets.

8. The multifunctional device for realizing multi-stage particle deposition and collection in thermal spraying according to claim 1, characterized in that: The tank body is fixed on a bracket with bolts. The bracket needs to be stable and have lockable wheels at the bottom so that it can move in any direction. The bracket is made of aluminum alloy or steel. Inflammable materials such as plastic and wood cannot be used. A handle can be installed on the tank body.

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