CN116103600A

CN116103600A - Multifunctional device for realizing multistage particle deposition and collection in thermal spraying

Info

Publication number: CN116103600A
Application number: CN202211534111.1A
Authority: CN
Inventors: 孙文海; 王晓明; 韩国峰; 杨柏俊; 张锁德; 吕威闫; 韩冬; 王建强
Original assignee: Institute of Metal Research of CAS
Current assignee: Institute of Metal Research of CAS
Priority date: 2022-12-01
Filing date: 2022-12-01
Publication date: 2023-05-12

Abstract

The invention discloses a multifunctional device for realizing multi-stage particle deposition and collection in thermal spraying, and belongs to the technical field of thermal spraying. The device comprises a tank body, a rotating shaft, a front baffle, a rear baffle and a rotary shielding mechanism; wherein: the two ends of the tank body are respectively provided with a front baffle plate and a rear baffle plate, an inlet module is arranged on the front baffle plate, and spray flame flows enter the tank body through the inlet module; a rotating shaft is arranged on the rear baffle, one end of the rotating shaft penetrates through the rear baffle to enter the tank body, and a sample plate is arranged at one end of the rotating shaft entering the tank body; the rotary shielding mechanism is arranged on the outer side of the front baffle, and is provided with a window, and the position of the window corresponds to the position of the inlet module. The device can adjust parameters such as spraying distance, air inflow size, 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, hot spraying and the like.

Description

Multifunctional device for realizing multistage particle deposition and collection in thermal spraying

Technical Field

The invention relates to the technical field of thermal spraying, in particular to a multifunctional device for realizing multistage particle deposition and collection in thermal spraying.

Background

The thermal spraying technology is to heat the spraying material to molten or semi-molten state fast with heat source, and to spray and deposit molten or semi-molten particles onto the surface of the pretreated substrate at high speed to form flattened particles with great amount of deposited particles to form coating. The raw materials used in the thermal spraying technology are generally powder or wire materials, and the variety of heat sources used is large, and the heat sources include electric arcs, plasma arcs, fuel combustion and the like. Depending on the heat source or technology used, there are various thermal spray techniques such as flame spray, plasma spray, explosion spray, supersonic flame spray, supersonic plasma spray, etc.

Thermal spray technology produces a special working surface on the surface of a treated common material (typically metal) to achieve: the special working surface is called a coating, and the process of manufacturing the coating utilizes fuel combustion and heating to generate energy, so that the working method for manufacturing the coating is called thermal spraying. Thermal spraying technology is one of the important components of surface engineering technology, and is an indispensable processing technology for the modern industry.

The core of thermal spray technology is the spray process parameters, and the properties of the prepared coating often depend on the coating material and the thermal spray process. Important technical parameters of the thermal spraying technology are as follows: powder feeding amount (wire feeding speed), heat source temperature (power), spraying distance, spray gun moving speed and spraying angle. The parameters are required to be determined and optimized in the thermal spraying process, so that a large number of orthogonal tests are necessarily generated, and great workload is brought to process optimization.

From the mechanism of coating formation, the process of forming a coating is a process in which a large number of molten or semi-molten particles collide, deform, cool and accumulate on the surface of the substrate. Therefore, the properties of the molten particles, such as temperature, speed, molten state, composition, etc., become critical to the performance of the coating. The macroscopic thermal spraying process improvement can be guided at the microscopic level starting from the properties of the molten particles. In order to reduce the great amount of work brought by the orthogonal test, it is necessary to analyze the characteristics of molten or semi-molten particles in the spraying process in the flying process, such as the surface state, the oxygen content, the molten state, the chemical composition (burning loss) and the like, and based on this, find out the influence rule of the thermal spraying process on the characteristics of the molten or semi-molten particles, thereby better obtaining the optimal spraying process.

There are some methods for obtaining molten particles, mainly water quenching, air cooling and liquid nitrogen cooling. When a water quenching method is used, some spraying materials react with water (such as active metals and the like) at high temperature, and the collected powder is not in a real thermal spraying process; when the liquid nitrogen cooling method is adopted, the high-temperature molten particles are rapidly solidified after touching the liquid nitrogen due to extremely low liquid nitrogen temperature, so that the state of the particles in the flight time, such as oxygen content and the like, can be maintained to the greatest extent.

In order to research the mechanism of forming the coating, the effect of depositing the molten particles is evaluated, and the research on the most basic unit of the coating, namely a single particle deposition point, is particularly important. In order to observe the single particle deposition point, methods of reducing the powder delivery amount, searching at the edge of the sample, etc. are generally used, but this is insufficient to obtain the deposition state under a real spray process. For this purpose, the invention realizes the acquisition of single-particle and multi-particle deposition samples under each spraying process by adopting a particle separation system (consisting of a rotary shielding plate, an inlet module and a rotary sample). Providing an accurate sample for the research of thermal spraying coating.

Disclosure of Invention

The invention aims to provide a multifunctional device for realizing multistage particle deposition and collection in thermal spraying, which can obtain single particle and multi-particle deposition samples in the thermal spraying process and provide a precise and accurate sample for the research of the spraying process and the mechanism research; the in-flight molten and semi-molten particles can also be captured in real time during thermal spraying and rapidly cooled and collected. And (3) guiding the optimization of the thermal spraying process by researching and analyzing the obtained powder, and finally obtaining the high-performance coating.

In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:

a multifunctional device for realizing multi-stage particle deposition and collection in thermal spraying comprises a tank body, a rotating shaft, a front baffle, a rear baffle and a rotary shielding mechanism; wherein: the two ends of the tank body are respectively provided with a front baffle plate and a rear baffle plate, an inlet module is arranged on the front baffle plate, and spray flame flows enter the tank body through the inlet module; a rotating shaft is arranged on the rear baffle, one end of the rotating shaft penetrates through the rear baffle to enter the tank body, and a sample plate is arranged at one end of the rotating shaft entering the tank body; the rotary shielding mechanism is arranged on the outer side of the front baffle, and is provided with a window, and the position of the window corresponds to the position of the inlet module.

An air inlet pipe is arranged below the tank body (collecting tank) at a position close to the front baffle plate, and an exhaust pipe is arranged below the tank body at a position close to the rear baffle plate; the air inlet pipe and the air outlet pipe are used for inputting and outputting inert gases; the front baffle plate and the rear baffle plate are detachably connected with the tank body so as to facilitate cleaning of the tank body and collection of powder in the tank.

The front baffle and the rear baffle are fixed with the tank body by adopting hook bolts, and a high-temperature-resistant rubber ring is arranged in the middle of the front baffle and the rear baffle to ensure the tightness of the tank body; the front baffle, the rear baffle and the tank body are made of stainless steel, and all the inner surfaces are polished, so that the influence of impurities such as rust on the results is avoided, and the adhesion of molten particles and the inner wall can be avoided.

The upper part of the tank body is provided with a liquid nitrogen tank, the top of the liquid nitrogen tank is provided with a pressurizing air pipe, the bottom of the liquid nitrogen tank is sequentially connected with a valve and a nozzle, and the nozzle stretches into the tank body; spraying liquid nitrogen in the liquid nitrogen tank from a nozzle into the tank body to form a liquid nitrogen curtain so as to rapidly cool molten particles in the tank body; not only ensures that the molten particles can be contacted with liquid nitrogen to realize rapid solidification and cooling, but also saves liquid nitrogen and reduces test cost.

The rear baffle is provided with a hole I for penetrating through the rotating shaft, 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, and the rotating shaft drives the sample plate to rotate around the axis of the rotating shaft when rotating; the rotation of the rotating shaft is powered by a rotating shaft motor.

The rotating shaft is of a telescopic structure, and the length of the rotating shaft entering the tank body is adjustable; the rotating shaft is marked with scales, so that the size of the expansion and contraction amount can be conveniently read out; the front end of the rotating shaft is provided with a clamping structure for installing the sample plate; the rotating speed of the rotating shaft is adjustable.

The inlet module is a single-layer stainless steel circular plate, the thickness is 1-5 mm, the diameter is 60mm, the inlet module and the front baffle are fixed by screws, and the replacement is convenient; the inlet module is designed to be single-hole type or multi-hole type, the aperture of the single-hole type inlet module is 0.5-10 mm, and the aperture is determined according to the actual requirement of research; the porous inlet module is provided with a plurality of small round holes, each round hole is arranged in a rectangular array of (5-8) x (5-8), and the diameter of each round hole is 0.1-0.5 mm.

The center of the front baffle is provided with a step-shaped round hole, the diameter of the inlet module is matched with that of the step-shaped round hole on the front baffle, and the inlet template is placed in the step-shaped round hole of the front baffle and then fixed through screws or pressing sheets.

The rotary shielding mechanism comprises a rotary shielding plate, a baffle support and a rotary motor; the rotary shielding plate is arranged between the center of the front shielding plate and a spray gun (used for spraying flame flow), the rotary shielding plate is a round metal sheet, a window with the diameter of 100mm is arranged at the position, close to the edge, of the rotary shielding plate, and molten particles are sprayed into the tank body through the window and through the inlet template; the rotating power of the rotating shielding plate is provided by a rotating motor, and the rotating shielding plate is supported by a shielding plate bracket; the preparation of the spray single particle deposition or multi-particle deposition sample can be realized by adjusting the rotating speed of the rotary shielding plate, the model of the inlet module (the aperture and the number of holes) and the rotating speed of the rotating shaft.

The tank body is fixed on a bracket by bolts, the bracket needs to be stable, the bottom of the bracket is provided with a lockable wheel and can move towards any direction, the bracket is made of aluminum alloy or steel, and plastic wood and other inflammable materials cannot be used; the tank body can be provided with a handle.

The invention has the following advantages and beneficial effects:

1. the most basic unit of coating formation is a single particle deposition point, and the research of single particle and multiple instance deposition plays an important role in the research of a thermal spraying mechanism. The device for realizing thermal spraying single-particle and multi-particle deposition and collecting the molten particles in the thermal spraying flame flow, which is developed by the valve, can obtain single-particle deposition point samples and multi-particle deposition point samples, and provides direct samples for direct observation and research of thermal spraying particle deposition.

2. The characteristic study of molten and semi-molten particles is an important component of thermal spraying studies, but a molten particle capturing device has no commercial forming equipment. In order to solve the dilemma, the invention develops a device for realizing thermal spraying of single particles, multi-particle deposition and collecting of molten particles in thermal spraying flame flow, and provides a sample obtaining way for researching the characteristics of molten and semi-molten particles which are key parameters in the thermal spraying process.

3. The device of the invention rapidly cools and solidifies the molten particles by using a liquid nitrogen spraying mode, thereby ensuring that the molten particles can be contacted with the liquid nitrogen to realize rapid solidification and cooling, saving the liquid nitrogen and reducing the test cost;

4. the device can realize the preparation of single-particle and multi-particle deposition point samples by adjusting the rotating speeds of the rotary shielding plate, the rotating shaft and the like and matching with different inlet modules.

5. The device can effectively capture molten and semi-molten particles, and collect different quantities of molten particles by replacing different inlet modules.

6. The inlet module used by the device has the advantages of simple structure, small volume, low cost and convenient replacement. The large-scale test is free of economic and time cost pressures.

7. The device is suitable for various thermal spraying such as flame spraying, supersonic flame spraying, plasma spraying and the like.

Drawings

FIG. 1 is a schematic view of an apparatus for collecting molten particles in a thermal spray flame stream according to the present invention.

FIG. 2 is a schematic diagram of the connection structure of the exhaust pipeline and the tank body.

FIG. 3 is a schematic view of the structure of the air inlet pipe of the tank body close to the front baffle plate.

FIG. 4 is a schematic view of the structure of the tailgate of the invention.

Fig. 5 is a schematic view of the structure of the front baffle of the present invention.

FIG. 6 is a schematic view of the inlet module of the present invention.

FIG. 7 is a schematic view of a rotating shutter structure according to the present invention.

Fig. 8 is a SEM photograph of the thermal spray powder collected in example 2.

Fig. 9 is a SEM photograph of the thermal spray powder collected in example 4.

FIG. 10 is a photograph of thermal spray multiparticulate deposition collected in example 3.

FIG. 11 is a photograph of thermal spray single particle deposition collected in example 1; wherein: (a), (b) and (c) are photographs of three particles therein.

In the figure: 1-a tank body; 2-a tailgate; 301-template; 302-a spindle motor; 303-rotating shaft; 4-an exhaust duct; 5-a bracket; 6-a front baffle; 601-a step hole; 602-shifting sheets; 603-a front baffle rubber ring groove; 701-a rotating electrical machine; 702-rotating a shutter; 703-a window; 704-a baffle bracket; 8-an inlet module; 801-round holes; 802-an inlet module rubber ring groove; 9-a liquid nitrogen tank; 901-pressurizing air pipe; 902-a valve; 903-liquid nitrogen nozzle; 10-front shielding plate; 11-an air inlet pipe.

Detailed Description

For a further understanding of the present invention, reference should be made to the following description of the invention taken in conjunction with the accompanying drawings and examples, which are provided to illustrate further features and advantages of the invention, and not to limit the scope of the claims.

In order to study the particle deposition mechanism and the characteristic problems of fused and semi-fused particles in the thermal spraying process, the invention provides a device for realizing the deposition of multi-stage particles (single particles and multiple particles) of thermal spraying and collecting fused particles in a thermal spraying flame flow, which can be used for the study of the thermal spraying mechanism and the parameter optimization and adjustment of various thermal spraying processes, and the structure is shown in figures 1-7. The device comprises a tank body 1, a rear baffle 2, 301-sample plates, a rotating shaft 303, a bracket 5, a front baffle 6, a rotating shielding plate 702, an inlet module 8, a liquid nitrogen tank 9, a front shielding plate 10 and the like.

As shown in figure 1, the tank body 1 is made of stainless steel, the diameter is 100-300 mm, the inside is polished, flange rings are arranged on two sides of the tank body and are respectively connected with the front baffle 6 and the rear baffle 2, the front baffle and the rear baffle are made of stainless steel, and the inside is polished. The tank body is fixed on the bracket 5 through screws. A stainless steel air inlet pipe 11 is arranged at the front part of the tank body 1 near the front baffle, and the stainless steel air inlet pipe 11 is welded with the tank body 1; the stainless steel air inlet pipe 11 can be connected with an inert gas source (such as a gas cylinder) by adopting a soft air pipe. A liquid nitrogen tank 9 is further arranged above the tank body 1 and close to the front baffle plate, and an exhaust pipeline 4 is further arranged below the tank body 1 and close to the rear baffle plate; the rear baffle 2, the front baffle 6 and the liquid nitrogen tank 9 are connected with the tank body 1 by adopting hook bolts or welding modes; rubber rings are arranged at the joints of the tank body 1, the exhaust pipeline 4, the rear baffle plate 2 and the front baffle plate 6 so as to avoid air leakage. The front shielding plate 10 is made of stainless steel or steel, is fixed on the tank body 1 through bolts and is used for shielding the liquid nitrogen tank 9 and preventing spraying flame flow from directly acting on the liquid nitrogen tank 9.

As shown in fig. 2, the exhaust pipe 4 is connected with the exhaust port at the bottom end of the tail of the tank body in a quick-release manner. The shape of the exhaust pipeline 4 is a 'permutation' type, the diameter of the pipeline is 30-60mm, which is beneficial to smoothly exhausting inert gas and keeping powder wrapped in the gas at the bent part of the pipeline.

As shown in fig. 3, the backplate 2 is provided with a hole i for installing a rotating shaft, the hole i deviates from the center of the backplate, so that the axis of the rotating shaft deviates from the axis of the tank body, and when the rotating shaft rotates, the template is driven 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 of 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 with the tank body through a hook bolt or a fastening bolt, and a high-temperature-resistant rubber ring is arranged in the middle to keep sealing. The rotating shaft 303 is marked with scales, so that the size of the expansion and contraction amount can be conveniently read out; the length of the tank body 1 can be adjusted; the front end (the end stretching into the jar body) of pivot 303 installs template 301, and pivot 303 passes through pivot motor 302 and realizes rotatory, and the rotational speed is stable, adjustable.

As shown in fig. 4, the liquid nitrogen tank 9 is of a double-layer stainless steel design, the bottom of the liquid nitrogen tank 9 is connected with the valve 902 through a bolt, a sealing rubber ring is arranged in the middle of the valve 902, and the valve 902 is an electric or pneumatic valve; the top of the liquid nitrogen tank 9 is provided with a pressurizing air pipe 901, the pressurizing air pipe 901 is connected with the liquid nitrogen tank 9 through threads, and a sealing rubber ring is arranged in the middle; the bottom valve 902 of the liquid nitrogen tank 9 is an electric or pneumatic valve; the valve 902 is connected with the liquid nitrogen nozzle 903, the valve is connected with the liquid nitrogen nozzle 903 in a quick-release way, and a sealing rubber ring is arranged in the middle; the liquid nitrogen nozzle 903 is welded to the tank 1, and may spray liquid nitrogen into the tank in a specified direction.

As shown in fig. 5, the front baffle 6 is a circular stainless steel plate, a step hole 601 is formed in the middle, 4 paddles 602 for fixing the inlet module 8 are uniformly arranged near the inner edge, and a front baffle rubber ring groove 603 for placing a rubber ring is formed near the outer edge.

As shown in fig. 6, the inlet module 8 is a single-layer stainless steel circular plate, and the diameter of the inlet module is matched with that of the stepped circular hole of the front baffle; the outer edge of the inlet module 8 is arranged in a step shape, the outer ring is provided with an inlet module rubber ring groove 802, one or a plurality of round holes 801 are uniformly distributed in the center, the outer edge of the inlet module 8 is matched with the step-shaped holes on the front baffle 6, and when in use, the inlet module 8 is placed in the step-shaped holes 601 of the front baffle 6 and is fixed by the poking sheets 602 or screws.

As shown in fig. 7, the rotating shielding plate 702 is a circular metal plate, and a window 703 with a diameter of 100mm is formed near the edge for the passage of molten particles, and when the window 703 is located at the highest position, the center height of the window is the same as the center height of the inlet module. The adjustable speed rotation of the rotating shutter can be achieved using the rotating motor 701 and the shutter support 704 is used as a support.

The support 5 is made of aluminum alloy or other materials (such as steel), is stable in structure and capable of adjusting the height, and the bottom end of the support is provided with a plurality of lockable universal wheels, so that the support is convenient to move and fix. The support should be as stable as possible to avoid toppling over by impact during the powder collection by thermal spraying, for ease of movement. The tank body is fixed on the bracket through bolts.

The tank body is detachably connected with all parts, so that the cleaning is convenient. The total of 1 tank

air inlet pipe

11 and 1 pressurizing air pipe 901 can be connected with an inert gas steel bottle or a pipeline by using a hose, and the pressure of the air inlet is regulated by a pressure reducing valve arranged at an air source.

In a single particle deposition sample preparation test, in order to realize single particle deposition, the preparation of the single particle deposition sample is realized by adjusting the rotating speed of a shielding plate, adjusting the rotating speed of a rotating shaft and replacing inlet modules of different types to shield almost all spray particles. Likewise, these parameters may also be adjusted to achieve multiparticulate deposition.

In the powder collection test, the quantity of the collected powder is different, and the inlet module has two designs of single-hole type and multi-hole array type in order to meet the test requirement. The aperture of the single-hole inlet module can be 0.5-10 mm, and the aperture is determined according to actual requirements; the porous inlet module can be composed of a plurality of small round holes, the round holes Kong Zhenwei are rectangular arrays with the diameters of 5-8 multiplied by 5-8, and the diameters of the round holes are 0.1-0.5 mm. The inlet module is designed for quick replacement, and is replaced immediately after the small hole is blocked.

Example 1:

and after all the components are installed, the inlet module is of a single-hole structure, the aperture is 0.1mm, and the inlet module is installed on the front baffle and is fixed by using screws and a pulling piece. The pushing device is moved to a set position, the support lifting screw rod is rotated, the center height of the inlet module is adjusted to be 1.2 meters, and the support locking device is started. And (3) opening a rear baffle, after sand blasting treatment of a sample (template), installing the rear baffle at a sample clamp of the rotating shaft, adjusting the length of the rotating shaft extending into the tank body to 400mm (at the moment, the spraying distance is 400 mm), and fixing the rotating shaft on a rotating motor. The position of the shielding plate is adjusted so that the window of the shielding plate can be opposite to the center of the inlet module when rotating. And adjusting a thermal spraying spray gun movement program, so that when the spray gun moves, a spray gun opening passes through the center position of the inlet module, and the spray gun opening is 200mm away from the inlet module. The liquid nitrogen valve was closed. The air inlet pipe is connected with a high-purity argon steel cylinder, and the set gas pressure is 0.3MPa. And opening an air inlet pipe valve, filling argon into the tank body, and continuing until the test is finished.

And after the spray gun passes through the position of the inlet module once, the spray gun stops moving, the thermal spraying system is closed, the air inlet pipe valve is closed, the rotation of the shielding plate is stopped, the rotation of the rotating shaft is stopped, the test is ended, and a single particle deposition sample is obtained. The sample was removed. The thermal spray single particle deposition photograph collected in this example is shown in fig. 11.

Example 2:

and after all the components are installed, the inlet module is of a single-hole structure, the aperture is 0.5mm, and the inlet module is installed on the front baffle and is fixed by using screws and a pulling piece. The pushing device is moved to a set position, the support lifting screw rod is rotated, the center height of the inlet module is adjusted to be 1.2 meters, and the support locking device is started. The position of the rotary shielding plate is adjusted so that the window of the shielding plate is opposite to the center of the inlet module. And adjusting the position of the thermal spraying spray gun to enable a spray gun opening to be opposite to the center of the inlet module, defining the position of the spray gun as a powder collecting position, and recording the position of the spray gun. Closing a liquid nitrogen valve, adding liquid nitrogen into a liquid nitrogen tank, connecting a pressurizing air pipe with a nitrogen steel bottle, setting the gas pressure to be 0.5MPa, connecting an air inlet pipe with a high-purity argon steel bottle, and setting the gas pressure to be 0.3MPa. And opening an air inlet pipe valve, filling argon into the tank body, and stopping the test continuously.

And (3) opening the thermal spraying equipment at another position, after the spraying state is stable, opening a liquid nitrogen tank valve, opening a pressurizing air pipe valve, rapidly moving the spray gun to a powder collecting position, rapidly removing the spray gun after spraying at the powder collecting position for 10 seconds, then closing the thermal spraying system, closing an air inlet pipe valve, and closing the pressurizing air pipe valve.

The canister is opened to collect the powder. The powder is mainly arranged at the bending parts of the lower part of the tank body and the exhaust pipe. After powder collection, the powder was vacuum packed and marked for analysis. Cleaning the inner part of the tank body and the inner wall of the scheduling pipe so as to avoid polluting the next collection test. The powder collection is thus complete. SEM photographs of the thermal spray powder collected in this example are shown in fig. 8.

Example 3:

and after all the components are installed, the inlet module is of a single-hole structure, the aperture is 0.3mm, and the inlet module is installed on the front baffle and is fixed by using screws and a pulling piece. The pushing device is moved to a set position, the support lifting screw rod is rotated, the center height of the inlet module is adjusted to be 1.2 meters, and the support locking device is started. And opening the rear baffle, after carrying out sand blasting treatment on the sample, installing the rear baffle at a sample clamp of the rotating shaft, adjusting the length of the rotating shaft extending into the tank body to 350mm (at the moment, the spraying distance is 350 mm), and fixing the rotating shaft on the rotating motor. The position of the shielding plate is adjusted so that the window of the shielding plate can be opposite to the center of the inlet module when rotating. And adjusting a thermal spraying spray gun movement program, so that when the spray gun moves, a spray gun opening passes through the center position of the inlet module, and the spray gun opening is 200mm away from the inlet module. The liquid nitrogen valve was closed. The air inlet pipe is connected with a high-purity argon steel cylinder, and the set gas pressure is 0.3MPa. And opening an air inlet pipe valve, filling argon into the tank body, and stopping the test continuously.

And after the spray gun passes through the position of the inlet module once, the spray gun stops moving, the thermal spraying system is closed, the air inlet pipe valve is closed, the rotation of the shielding plate is stopped, the rotation of the rotating shaft is stopped, the test is ended, and the multi-particle deposition sample is obtained. The sample was removed. The thermal spray multi-particle deposition photograph collected in this example is shown in fig. 10.

Example 4:

and after all the components are installed, the inlet module is of a porous structure, the pore arrays are arranged for 5X5, each pore diameter is 0.2mm, and the pore spacing is 3mm. The inlet module is mounted on the front baffle and is fixed using screws and dials. The pushing device is moved to a set position, the support lifting screw rod is rotated, the center height of the inlet module is adjusted to be 1.2 meters, and the support locking device is started. The position of the rotary shielding plate is adjusted so that the window of the shielding plate is opposite to the center of the inlet module. And adjusting the position of the thermal spraying spray gun to enable a spray gun opening to be opposite to the center of the inlet module, defining the position of the spray gun as a powder collecting position, and recording the position of the spray gun. Closing a liquid nitrogen valve, adding liquid nitrogen into a liquid nitrogen tank, connecting a pressurizing air pipe with a nitrogen steel bottle, setting the gas pressure to be 0.5MPa, connecting an air inlet pipe with a high-purity argon steel bottle, and setting the gas pressure to be 0.3MPa. And opening an air inlet pipe valve, filling argon into the tank body, and stopping the test continuously.

The canister is opened to collect the powder. The powder is mainly arranged at the bending parts of the lower part of the tank body and the exhaust pipe. After powder collection, the powder was vacuum packed and marked for analysis. Cleaning the inner part of the tank body and the inner wall of the scheduling pipe so as to avoid polluting the next collection test. The powder collection is thus complete. SEM photographs of the thermal spray powder collected in this example are shown in fig. 9.

Claims

1. A multifunctional device for realizing multi-stage particle deposition and collection in thermal spraying is characterized in that: the device comprises a tank body, a rotating shaft, a front baffle, a rear baffle and a rotary shielding mechanism; wherein: the two ends of the tank body are respectively provided with a front baffle plate and a rear baffle plate, an inlet module is arranged on the front baffle plate, and spray flame flows enter the tank body through the inlet module; a rotating shaft is arranged on the rear baffle, one end of the rotating shaft penetrates through the rear baffle to enter the tank body, and a sample plate is arranged at one end of the rotating shaft entering the tank body; the rotary shielding mechanism is arranged on the outer side of the front baffle, and is provided with a window, and the position of the window corresponds to the position of the inlet module.

2. The multifunctional apparatus for achieving multi-stage particle deposition and collection in thermal spraying according to claim 1, wherein: an air inlet pipe is arranged below the tank body (collecting tank) at a position close to the front baffle plate, and an exhaust pipe is arranged below the tank body at a position close to the rear baffle plate; the air inlet pipe and the air outlet pipe are used for inputting and outputting inert gases; the front baffle plate and the rear baffle plate are detachably connected with the tank body so as to facilitate cleaning of the tank body and collection of powder in the tank.

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

4. The multifunctional apparatus for achieving multi-stage particle deposition and collection in thermal spraying according to claim 1, wherein: the upper part of the tank body is provided with a liquid nitrogen tank, the top of the liquid nitrogen tank is provided with a pressurizing air pipe, the bottom of the liquid nitrogen tank is sequentially connected with a valve and a nozzle, and the nozzle stretches into the tank body; spraying liquid nitrogen in the liquid nitrogen tank from a nozzle into the tank body to form a liquid nitrogen curtain so as to rapidly cool molten particles in the tank body; not only ensures that the molten particles can be contacted with liquid nitrogen to realize rapid solidification and cooling, but also saves liquid nitrogen and reduces test cost.

5. The multifunctional apparatus for achieving multi-stage particle deposition and collection in thermal spraying according to claim 1, wherein: the rear baffle is provided with a hole I for penetrating through the rotating shaft, 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, and the rotating shaft drives the sample plate to rotate around the axis of the rotating shaft when rotating; the rotation of the rotating shaft is powered by a rotating shaft motor.

6. The multifunctional apparatus for achieving multi-stage particle deposition and collection in thermal spraying according to claim 5, wherein: the rotating shaft is of a telescopic structure, and the length of the rotating shaft entering the tank body is adjustable; the rotating shaft is marked with scales, so that the size of the expansion and contraction amount can be conveniently read out; the front end of the rotating shaft is provided with a clamping structure for installing the sample plate; the rotating speed of the rotating shaft is adjustable.

7. The multifunctional apparatus for achieving multi-stage particle deposition and collection in thermal spraying according to claim 1, wherein: the inlet module is a single-layer stainless steel circular plate, the thickness is 1-5 mm, the diameter is 60mm, the inlet module and the front baffle are fixed by screws, and the replacement is convenient; the inlet module is designed to be single-hole type or multi-hole type, the aperture of the single-hole type inlet module is 0.5-10 mm, and the aperture is determined according to the actual requirement of research; the porous inlet module is provided with a plurality of small round holes, each round hole is arranged in a rectangular array of (5-8) x (5-8), and the diameter of each round hole is 0.1-0.5 mm.

8. The multifunctional apparatus for achieving multi-stage particle deposition and collection in thermal spraying according to claim 1, wherein: the center of the front baffle is provided with a step-shaped round hole, the diameter of the inlet module is matched with that of the step-shaped round hole on the front baffle, and the inlet template is placed in the step-shaped round hole of the front baffle and then fixed through screws or pressing sheets.

9. The multifunctional apparatus for achieving multi-stage particle deposition and collection in thermal spraying according to claim 1, wherein: the rotary shielding mechanism comprises a rotary shielding plate, a baffle support and a rotary motor; the rotary shielding plate is arranged between the center of the front shielding plate and a spray gun (used for spraying flame flow), the rotary shielding plate is a round metal sheet, a window with the diameter of 100mm is arranged at the position, close to the edge, of the rotary shielding plate, and molten particles are sprayed into the tank body through the window and through the inlet template; the rotating power of the rotating shielding plate is provided by a rotating motor, and the rotating shielding plate is supported by a shielding plate bracket; the preparation of the spray single particle deposition or multi-particle deposition sample can be realized by adjusting the rotating speed of the rotary shielding plate, the model of the inlet module (the aperture and the number of holes) and the rotating speed of the rotating shaft.

10. The multifunctional apparatus for achieving multi-stage particle deposition and collection in thermal spraying according to claim 1, wherein: the tank body is fixed on a bracket by bolts, the bracket needs to be stable, the bottom of the bracket is provided with a lockable wheel and can move towards any direction, the bracket is made of aluminum alloy or steel, and plastic wood and other inflammable materials cannot be used; the tank body can be provided with a handle.