A powder feeder for various materials and its working method

Abstract

The application belongs to the technical field of laser cladding, and discloses a powder feeder convenient to recycle and suitable for various materials and a working method thereof, which comprises a gas cylinder, a plurality of powder feeding devices and a total powder feeding pipe; each powder feeding device comprises a powder bucket cover and a powder bucket, a sleeve extends from the top of the powder bucket cover to the inside of the powder bucket; a screw rod is arranged in the sleeve and is driven by a motor; a filter screen is arranged at the lower part of the sleeve, and a heating device is arranged in the screw rod to heat the powder in conveying; a powder feeding pipe is arranged near the top of the sleeve, and the powder feeding pipes of each powder feeding device are respectively connected with the total powder feeding pipe through a tee joint; one end of the total powder feeding pipe is connected with the gas cylinder, and the other end is a powder outlet; the gas cylinder also sends gas into the inside of the powder feeding device through a gas conveying pipe. The mixed powder feeding mode of screw conveying as the main mode and gas negative pressure conveying as the auxiliary mode realizes the requirements of stable powder supply and uniform mixed powder supply.

Description

Technical Field

[0001] This invention relates to the field of laser cladding technology, specifically to a powder feeder that is easy to recycle and applicable to a variety of materials, and its working method. Background Technology

[0002] With the iterative development of laser cladding technology, a single coating is difficult to meet the requirements of multiple performances. Functionally graded coatings have gradually become a hot topic in the field of laser cladding, which requires the alternating use of multiple metal powders in their preparation.

[0003] However, existing powder feeding devices cannot ensure the removal of residual powder on the powder pipeline when switching powders, which will cause contamination of the powder feeding path and seriously affect the forming efficiency and quality of functional gradient coatings. Although some patented technologies can remove residual powder on the powder pipeline, their structures are relatively complex and their practicality is poor. In addition, for powder coating cladding, factors such as humid environments may affect the "agglomeration" phenomenon, which will promote the formation of defects such as pores and affect the cladding quality. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a powder feeder and its working method that is easy to recycle and applicable to various materials. It adopts a mixed powder feeding method with screw conveying as the main method and gas negative pressure conveying as a supplement, so as to achieve the needs of stable powder supply and uniform mixed powder supply.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] In a first aspect, the present invention provides a powder feeder that is easy to recycle and suitable for a variety of materials, including a gas cylinder, multiple powder feeding devices and a main powder feeding pipe;

[0007] Each powder feeding device includes a powder hopper lid and a powder hopper. A sleeve extends from the top of the lid into the hopper. A screw rod is installed inside the sleeve, driven by a motor located at the top of the lid. A filter screen is installed at the bottom of the sleeve, and a heating device is installed inside the screw rod to heat the powder being fed. A powder feeding pipe is located near the top of the sleeve, and each device's pipe is connected to the main feeding pipe via a T-connector. One end of the main feeding pipe is connected to a gas cylinder, and the other end is the powder outlet. The gas cylinder also supplies gas to the powder feeding device via a gas supply pipe. This powder feeder adopts an integrated and compact design. Through gas and powder separation, it effectively avoids contamination along the powder feeding path, meets the requirements of small installation space, allows for modular quick assembly and disassembly, and achieves zero powder leakage and high recovery rate.

[0008] As a further technical solution, the three-way connector includes an air inlet, a powder inlet, and a powder outlet; wherein a first variable diameter section and a second variable diameter section are provided inside the air inlet; the inner diameter of the first variable diameter section gradually decreases along the direction of airflow, and the inner diameter of the second variable diameter section gradually increases along the direction of airflow.

[0009] As a further technical solution, a first powder sensor and a solenoid valve are installed on the powder feeding pipe; the first powder sensor is used to monitor the powder flow rate in the powder feeding pipe; the solenoid valve is used to control the opening and closing of the powder feeding pipe.

[0010] As a further technical solution, a second powder sensor is installed at the end of the main powder feeding pipe; the second powder sensor is used to monitor the powder flow rate in the main powder feeding pipe.

[0011] As a further technical solution, a base support is also included, with a gas cylinder placed at the center of the base support and multiple powder feeding devices arranged around the gas cylinder; the main powder feeding pipe is an annular pipe that connects to each tee joint.

[0012] As a further technical solution, the base support includes a base, on which multiple support rods are vertically arranged, forming a circle, with the top connected to a ring. A ring of support plates is arranged in sequence around the circumference of the ring. Each support plate is arranged along the radial direction of the ring, and the end of the support plate is connected to a powder feeding device. The gas cylinder is arranged inside the circle formed by the multiple support rods.

[0013] As a further technical solution, anti-slip patterns are provided on the spiral blades of the screw rod, and replaceable wear-resistant strips are provided at the edge of the threaded blades.

[0014] As a further technical solution, a switch valve is installed on the connecting pipeline between the gas cylinder and the main powder delivery pipe, and a switch valve is also installed on the connecting pipeline between the gas cylinder and the gas delivery pipe.

[0015] As a further technical solution, the motor, switching valve, and solenoid valve of each of the above-mentioned powder feeding devices are controlled by the control system to realize the automatic control of the entire system.

[0016] Secondly, based on the aforementioned powder feeder that is easy to recycle and suitable for various materials, the present invention also provides a working method, as follows:

[0017] First, different powders are poured into different powder feeding devices;

[0018] The gas cylinder supplies protective gas to the main powder feeding pipe and the gas supply pipe of the first powder feeding device. The motor starts the screw rod to rotate and feed the powder upward. Under the combined action of gravity and air pressure, the powder in the powder bucket of the first powder feeding device passes through the filter screen to filter out the "agglomerated" powder and ensure that the powder particle size is uniform. The powder passes through the spiral blades and the screw rod equipped with a heating device to ensure that the powder is dry.

[0019] When the solenoid valve of the first powder feeding device is opened, the gas flow rate is relatively fast at the three-way connector, creating a negative pressure at the junction of the powder feeding pipe of the first powder feeding device, which further pushes the powder to flow into the main powder feeding pipe and enters the laser head; the first powder sensor of the first powder feeding device and the second powder sensor at the end of the powder feeding pipe can accurately monitor the powder flow rate and perform negative feedback adjustment on the motor to ensure stable and uniform powder delivery; if powder blockage occurs, the blockage location can be accurately determined through the flow feedback of the first powder sensor and the second powder sensor.

[0020] After the first type of powder cladding is completed, the solenoid valve of the first powder feeding device is closed, and the motor of the first powder feeding device reverses to ensure that the powder on the spiral blades slides back to the bottom of the barrel. The protective gas in the powder feeding pipe continues to flow, and the second powder sensor continues to monitor the powder flow rate at the end of the powder feeding pipe and near the laser head. At the same time, during the process of the laser head returning to the cladding starting point, the protective gas can also blow away the first type of powder remaining on the substrate, minimizing human intervention. When the powder flow rate at the first powder sensor is zero, it means that there is no residual first type of powder in the powder feeding path.

[0021] At this point, the motor of the second powder feeding device is turned on, and the screw starts to rotate and stably convey the second type of powder upwards. The entire conveying process is the same as that of the first type of powder, so it will not be described in detail here.

[0022] If a third powder needs to be fed after the second powder has been fed, the same method is used to feed the third powder; and so on, thus achieving a functional gradient coating without powder contamination.

[0023] The beneficial effects of this invention are as follows:

[0024] This invention, through the design of a powder feeding device structure that works in conjunction with a gas cylinder and a main powder feeding pipe, achieves a stable supply of powder and a uniformly mixed powder by using a hybrid powder feeding method that primarily employs spiral conveying and secondarily uses negative pressure gas conveying. It can also feed powders of various materials. The gas cylinder supplies protective gas (such as argon or other inert gases) to the main powder feeding pipe and the powder feeding device's gas supply pipe. The motor starts the spiral rod, which begins to rotate and feed the powder upwards. Under the combined action of gravity and gas pressure, the powder in the powder container of the powder feeding device passes through a filter screen, filtering out "agglomerated" powder and ensuring uniform powder particle size. The powder passes through the spiral blades and a screw equipped with a heating device, ensuring the powder is dry. The motor reverses to ensure that the powder on the spiral blades slides back to the bottom of the container, while the protective gas continues to flow in the powder feeding pipe. The first powder sensor continues to monitor the powder flow rate at the end of the powder feeding pipe and near the laser head. Simultaneously, during the laser head's return to the cladding starting point, the protective gas also blows away any residual powder on the substrate, minimizing human intervention. When the powder flow rate at the second powder sensor is zero, it indicates that there is no residual powder in the powder feeding path.

[0025] Due to the reduced pipe diameter at the joint, the gas flow rate is faster, creating a negative pressure at the junction of the powder feeding pipes in the powder feeding device, which further pushes the powder to flow into the main powder feeding pipe and into the laser head.

[0026] The second powder sensor of the powder feeding device and the first powder sensor at the end of the powder feeding pipe can accurately monitor the powder flow rate and perform negative feedback regulation on the motor to ensure stable and uniform powder delivery. If powder blockage occurs, the blockage location can be accurately determined through the flow feedback from the first and second powder sensors.

[0027] When the experiment is over, loosen the latches on the two powder containers to disassemble them, thus achieving a high recovery rate of the remaining powder. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the powder feeding device disclosed in this embodiment;

[0029] Figure 2 This is a partial cross-sectional view of the powder feeding device disclosed in this embodiment;

[0030] Figure 3 This is a partial cross-sectional view of the powder feeding port disclosed in this embodiment;

[0031] Figure 4 This is a cross-sectional view of the tee connector disclosed in this embodiment;

[0032] Figure 5 This is a schematic diagram of the powder bucket as disclosed in this embodiment;

[0033] Figure 6 This is a schematic diagram of the overall base support disclosed in this embodiment;

[0034] In the diagram: 1. Gas cylinder; 2. Main powder delivery pipe; 3. Powder delivery device; 4. Base bracket; 5. T-connector; 6. First powder sensor; 31. Motor; 32. Powder delivery port; 33. Powder hopper lid; 34. Buckle; 35. Powder hopper; 36. Sleeve; 37. Filter screen; 38. Spiral rod; 39. Gas delivery pipe; 321. Second powder sensor; 322. Solenoid valve; 323. Powder delivery pipe; 381. Replaceable wear-resistant strip; 382. Anti-slip texture; 383. Heating device; 351. Sealing ring; 41. Fixing clamp; 42. Powder lid bracket; 43. Bracket; 44. Base; 45. Fixing pin; 51. Gas delivery port; 52. Powder inlet; 53. Powder outlet; 511. First diameter reducing section; 512. Second diameter reducing section; Detailed Implementation

[0035] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0036] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless otherwise expressly indicated by the invention, the singular form is also intended to include the plural form. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0037] For ease of description, the words "up," "down," "left," and "right" appearing in this invention only indicate that they are consistent with the up, down, left, and right directions of the accompanying drawings themselves. They do not limit the structure and are merely for the purpose of facilitating the description of this invention and simplifying the description. They do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0038] In existing technologies, during the functionally graded coating process of laser direct energy deposition (L-DED), when multiple powder feeders are used to alternately deliver different types of powder to the same laser head, two problems arise. First, residual powder from the previous type in the pneumatic delivery pipe and laser head can contaminate subsequently delivered powder, thus affecting the quality of the functionally graded coating. Second, while pre-feeding powder before the laser-directed energy deposition of the next type of powder can remove some residual powder from the previous type and reduce powder contamination during deposition, it also results in significant powder waste, especially when depositing high-cost alloy powders, which greatly increases experimental costs. Therefore, this invention designs a powder feeder that is easy to recycle and applicable to multiple materials, along with its operating method, to achieve the cleaning of residual powder in the pneumatic delivery pipe and laser head, and the recovery of remaining powder. Furthermore, by adjusting the base support and adding a powder feeding device, three or more different types of powder can be fed. This embodiment uses two types of powder feeding as an example for explanation.

[0039] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 As shown, the powder feeder disclosed in this embodiment, which is easy to recycle and suitable for various materials, mainly includes a gas cylinder 1, multiple powder feeding devices 3, and a main powder feeding pipe 2.

[0040] Furthermore, each powder feeding device 3 includes a powder bucket cover 33 and a powder bucket 35, which are connected by multiple snap fasteners 34. A sealing ring 351 is provided on the top of the powder bucket 35, and a sleeve 36 extends from the top of the powder bucket cover 33 into the inside of the powder bucket 35. A spiral rod 38 is provided inside the sleeve 36, which is driven by a motor 31 located on the top of the powder bucket cover. A filter screen 37 is provided at the lower part of the sleeve 36. The powder in the powder bucket 35 is filtered through the filter screen 37 and then enters the sleeve 36, where it is then pushed upward by the spiral rod 38. The powder is conveyed to the powder feeding pipe 323, which is equipped with a powder feeding port 32. A heating device 383 is installed inside the screw rod to heat the powder being conveyed. The powder feeding pipe 323 is located near the top of the sleeve 36 and is connected to the main powder feeding pipe 2 via a three-way connector 5. At the same time, the gas cylinder 1 also supplies gas into the powder feeding device 3 through the gas supply pipe 39. The purpose of supplying gas is mainly to increase the gas pressure inside the powder feeding device 3 and prevent low pressure from occurring inside the powder feeding device 3, which would prevent the powder from being conveyed.

[0041] Furthermore, to prevent the powder from slipping during the upward transport process, anti-slip grooves 382 are provided on the spiral blades of the spiral rod 38.

[0042] Furthermore, in order to prevent wear at the edge of the threaded blade, a replaceable wear-resistant strip 381 is provided at the edge of the threaded blade.

[0043] Furthermore, in order to support and fix the gas cylinder 1 and the multiple powder feeding devices 3, this embodiment also provides a base bracket 4, with the gas cylinder 1 placed at the center of the base bracket 4, and multiple powder feeding devices 3 arranged around the gas cylinder 1; the multiple powder feeding devices 3 are connected to the same main powder feeding pipe 2; one end of the main powder feeding pipe 2 is connected to the gas cylinder 1, and the other end is the powder outlet; the main powder feeding pipe 2 is an annular pipe that connects to each powder feeding device 3, and the powder in each powder feeding device 3 can enter the main powder feeding pipe 2 through the tee connector 5, thereby realizing the powder conveying.

[0044] As a further technical solution, such as Figure 3 As shown, a second powder sensor 321 and a solenoid valve 322 are installed on the powder feeding pipe 323; the second powder sensor 321 is used to monitor the powder flow rate in the powder feeding pipe 323; it performs negative feedback regulation on the motor to ensure stable and uniform powder delivery; the solenoid valve 322 is used to control the opening and closing of the powder feeding pipe 323.

[0045] As a further technical solution, a first powder sensor 6 is installed at the end of the main powder feeding pipe 2. The first powder sensor 6 is used to monitor the powder flow rate in the main powder feeding pipe 2. If powder blockage occurs, the blockage location can be accurately determined through the flow feedback of the first powder sensor 6 and the second powder sensor 321. If the flow rate of the first powder sensor 6 is zero, it is possible that both the main powder feeding pipe 2 and the powder feeding pipe 323 are blocked, or only the main powder feeding pipe 2 is blocked. If the flow rate of both the first powder sensor 6 and the second powder sensor 321 is zero, it indicates that both the main powder feeding pipe 2 and the powder feeding pipe 323 are blocked. If the flow rate of the first powder sensor 6 is zero, but the second powder sensor 321 has a flow rate value, it indicates that the main powder feeding pipe 2 is blocked. If the flow rate of the second powder sensor 321 is zero, it indicates that the powder feeding pipe 323 is blocked.

[0046] As a further technical solution, such as Figure 6 As shown, the base support 4 includes a base 44, on which multiple support rods are vertically arranged, forming a circle. The top of the support rods is connected to a ring to form a support 43. A series of fixed clamps 41 are arranged around the circumference of the ring. Each fixed clamp 41 is connected to a powder cap support 42. The end of the support plate is connected to the powder feeding device 3. A gas cylinder 1 is arranged inside the circle formed by the multiple support rods. The ring consists of multiple segments, which are connected to each other by fixing pins 45 to facilitate the installation of the powder feeding device 3.

[0047] As a further technical solution, the tee connector 5 in this embodiment is as follows: Figure 4As shown, it includes an air inlet 51, a powder inlet 52, and a powder outlet 53; wherein a first variable diameter section 511 and a second variable diameter section 512 are provided inside the air inlet 51; the inner diameter of the first variable diameter section gradually decreases along the direction of airflow, and the inner diameter of the second variable diameter section gradually increases along the direction of airflow; the main purpose of this design is to increase the gas flow rate at the joint, to form a negative pressure at the junction of the powder feeding pipe 323 of the first powder feeding device, and to further push the powder to flow into the main powder feeding pipe 2 and enter the laser head.

[0048] Furthermore, a switch valve is installed on the connecting pipeline between the gas cylinder 1 and the main powder delivery pipe 2, and a switch valve is also installed on the connecting pipeline between the gas cylinder 1 and the gas delivery pipe.

[0049] As a further technical solution, the motor of each powder feeding device 3, as well as each switching valve and solenoid valve 322, are all controlled by the control system to realize the automatic control of the entire system.

[0050] The specific working methods are as follows:

[0051] First, release the two powder buckets 35 by loosening the buckle 34, and pour the two mixed powders, the first powder and the second powder, into two different powder feeding devices 3 respectively. Pour the first powder into the first powder feeding device and the second powder into the second powder feeding device. Then, seal the first powder feeding device and the second powder feeding device by locking the buckle 34.

[0052] Furthermore, gas cylinder 1 supplies protective gas (such as inert gas like argon) to the main powder feeding pipe 2 and the gas supply pipe 39 of the first powder feeding device. Motor 31 starts the screw rod 38 to rotate and feed the powder upward. Under the combined action of gravity and air pressure, the powder in the powder bucket of the first powder feeding device passes through the filter screen 37 to filter out "agglomerated" powder, ensuring uniform powder particle size. The powder passes through the spiral blades and the screw equipped with the heating device 383 to ensure that the powder is dry.

[0053] The solenoid valve 322 of the first powder feeding device is opened. The main powder feeding pipe 2 and the powder feeding pipe 323 are connected by a three-way connector 5. Due to the reduced pipe diameter at the connector, the gas flow rate is faster, creating a negative pressure at the junction of the powder feeding pipe 323 of the first powder feeding device, further pushing the powder to flow into the laser head through the main powder feeding pipe 2. The second powder sensor 321 of the first powder feeding device and the first powder sensor 6 at the end of the powder feeding pipe can accurately monitor the powder flow rate and provide negative feedback adjustment to the motor to ensure stable and uniform powder delivery. If powder blockage occurs, the location of the blockage can be accurately determined through the flow feedback from the first powder sensor 6 and the second powder sensor 321.

[0054] Before cladding the second type of powder, solenoid valve 322 closes, and motor 31 of the first powder feeding device reverses to ensure that all powder on the spiral blades slides back to the bottom of the container. Protective gas continues to flow in the powder feeding pipe, and the first powder sensor 6 continues to monitor the powder flow rate at the end of the powder feeding pipe and near the laser head. Simultaneously, during the laser head's return to the cladding starting point, the protective gas can also blow away any residual first-type powder on the substrate, minimizing human intervention. When the powder flow rate at the second powder sensor 321 is zero, it indicates that there is no residual first-type powder in the powder feeding path.

[0055] At this time, the motor 31 of the second powder feeding device starts the screw rod 38 to rotate and stably convey the second type of powder upward. The entire conveying process is the same as that of the first type of powder, so it will not be described in detail here.

[0056] If a third powder needs to be fed after the second powder has been fed, the same method is used to feed the third powder; and so on, thus achieving a functional gradient coating without powder contamination. When the experiment is over, the powder can be disassembled by loosening the clips 34 of the two powder canisters 35, thereby achieving a high recovery rate of the remaining powder.

[0057] This invention proposes a powder feeder and its operating method that is easy to recycle and applicable to various materials. It achieves a stable supply of powder and a uniformly mixed powder by using a hybrid powder feeding method that primarily employs screw conveying and secondarily uses negative pressure gas conveying. Furthermore, the powder feeder adopts an integrated and compact structural design, effectively avoiding contamination of the powder feeding path through gas-powder separation, meeting the requirements of small installation space, and enabling modular quick assembly and disassembly, achieving zero powder leakage and a high recovery rate.

[0058] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A powder feeder that is easy to recycle and suitable for various materials, characterized in that, Includes gas cylinders, multiple powder feeding devices, and a main powder feeding pipe; Each powder feeding device includes a powder hopper lid and a powder hopper. A sleeve extends from the top of the lid into the powder hopper. A screw rod is installed inside the sleeve, driven by a motor located at the top of the lid. A filter screen is installed at the bottom of the sleeve, and a heating device is installed inside the screw rod to heat the powder being fed. A powder feeding pipe is located near the top of the sleeve, and each feeding pipe is connected to the main feeding pipe via a T-connector. One end of the main feeding pipe is connected to a gas cylinder, and the other end is a powder outlet. The gas cylinder also supplies gas to the powder feeding device via a gas supply pipe. A first powder sensor and a solenoid valve are installed on the feeding pipe. The first powder sensor monitors the powder flow rate in the feeding pipe, and the solenoid valve controls the opening and closing of the feeding pipe. A second powder sensor is installed at the end of the main feeding pipe, also monitoring the powder flow rate in the main feeding pipe. The gas cylinder supplies protective gas to the main powder feeding pipe and the gas supply pipe of the powder feeding device. The motor starts the screw to rotate and feed the powder upward. Under the combined action of gravity and air pressure, the powder in the powder bucket of the powder feeding device passes through the filter screen to filter out "agglomerated" powder, ensuring uniform powder particle size. The powder passes through the screw blades and the screw equipped with a heating device to ensure that the powder is dry. The motor reverses to ensure that the powder on the screw blades slides back to the bottom of the bucket, and the protective gas continues to flow in the powder feeding pipe. At the same time, during the process of the laser head returning to the cladding starting point, the protective gas can also blow away the powder remaining on the substrate, minimizing human intervention. When the powder flow rate at the second powder sensor is zero, it means that there is no residual powder in the powder feeding path.

2. The powder feeder for easy recycling and applicable to various materials as described in claim 1, characterized in that, The three-way connector includes an air inlet, a powder inlet, and a powder outlet; wherein a first variable diameter section and a second variable diameter section are provided inside the air inlet; the inner diameter of the first variable diameter section gradually decreases along the direction of airflow, and the inner diameter of the second variable diameter section gradually increases along the direction of airflow.

3. The powder feeder for easy recycling and applicable to various materials as described in claim 1, characterized in that, It also includes a base support, with a gas cylinder placed at the center of the base support and multiple powder feeding devices arranged around the gas cylinder; the main powder feeding pipe is an annular pipe that connects to each tee joint.

4. The powder feeder for easy recycling and applicable to various materials as described in claim 3, characterized in that, The base support includes a base, on which multiple support rods are vertically arranged, forming a circle. The top of the support rods is connected to a ring, and a ring of support plates is arranged in sequence around the circumference of the ring. Each support plate is arranged along the radial direction of the ring, and the end of the support plate is connected to a powder feeding device. The gas cylinder is arranged inside the circle formed by the multiple support rods.

5. The powder feeder for easy recycling and applicable to various materials as described in claim 1, characterized in that, Anti-slip patterns are provided on the spiral blades of the screw rod, and replaceable wear-resistant strips are provided at the edge of the threaded blades.

6. The powder feeder for easy recycling and applicable to various materials as described in claim 1, characterized in that, Switch valves are installed on both the connecting pipeline between the gas cylinder and the main powder delivery pipe and the connecting pipeline between the gas cylinder and the gas transmission pipe.

7. The powder feeder for easy recycling and applicable to various materials as described in claim 6, characterized in that, The motor, switching valve, and solenoid valve of each powder feeding device are controlled by the control system to achieve automatic control of the entire system.

8. The working method of the powder feeder that is easy to recycle and applicable to various materials as described in claim 1, characterized in that, Specifically as follows: Different powders are poured into different powder feeding devices; Gas cylinders supply protective gas to the main powder feeding pipe and the gas supply pipe of the first powder feeding device. The motor starts the screw to rotate and feed the powder upward. Under the combined action of gravity and air pressure, the powder particle size is ensured to be uniform. The powder passes through the screw blades and the screw equipped with a heating device to ensure that the powder is dry. When the solenoid valve of the first powder feeding device is opened, the gas flow rate is relatively fast at the three-way connector, and a negative pressure is formed at the junction of the powder feeding pipe of the first powder feeding device, which further pushes the powder to flow into the laser head through the main powder feeding pipe. The first powder sensor of the first powder feeding device and the second powder sensor at the end of the powder feeding pipe can accurately monitor the powder flow rate and perform negative feedback adjustment on the motor to ensure stable and uniform powder delivery. If powder blockage occurs, the location of the blockage can be accurately determined through the flow feedback from the first powder sensor and the second powder sensor. After the first type of powder cladding is completed, the solenoid valve of the first powder feeding device is closed, and the motor of the first powder feeding device reverses to ensure that the powder on the spiral blades slides back to the bottom of the barrel. The protective gas in the powder feeding pipe continues to flow, and the second powder sensor continues to monitor the powder flow rate at the end of the powder feeding pipe and near the laser head. At the same time, during the process of the laser head returning to the cladding starting point, the protective gas can also blow away the first type of powder remaining on the substrate. When the powder flow rate at the first powder sensor is zero, it means that there is no residual first type of powder in the powder feeding path. At this time, the motor of the second powder feeding device starts the screw rod to rotate and stably transport the second type of powder. The entire conveying process is the same as that of the first type of powder. If a third type of powder needs to be transported after the second type of powder is transported, the same method is used to transport the third type of powder. This process is repeated to achieve a functional gradient coating without powder contamination.

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