A method for preparing thermal barrier coating inside a narrow inner cavity thin-walled component

Abstract

The present invention relates to a device and method for spraying thermal barrier coatings inside thin-walled components with narrow inner cavities, and belongs to the field of advanced processing technology for spraying preparation methods and deformation control. A gun body stabilizing device is used to adjust the spray gun posture during the spraying process to ensure the uniformity of the prepared coating; a substrate cooling device is used for auxiliary cooling to reduce the deformation of the substrate during the spraying process and control the temperature of the workpiece during spraying; a powder rebound prevention device is used to reduce impurities, and a gas shielding curtain is formed by adjusting the gas discharge volume to prevent powder splashing and rebound; an exhaust dust removal device is used to promptly discharge dust and exhaust gas generated during the coating preparation process, ensuring that the coating is free of foreign matter during the preparation process; the stability of the coating preparation quality of the workpiece during the spraying process is effectively guaranteed, the degree of deformation of the workpiece during the spraying process is reduced, and the coating preparation quality is improved and the time used for coating preparation is reduced.

Description

Technical Field

[0001] The present invention relates to a device and method for spraying a thermal barrier coating inside a narrow inner cavity thin-walled component, belonging to the field of advanced processing technology of spraying preparation method and deformation control. Background Art

[0002] With the continuous development of aviation, aerospace engines and ground gas engines, the temperature resistance requirements of structural materials are gradually increasing. Coating thermal barrier coatings on the working surfaces of high-temperature components can not only improve the temperature bearing capacity of components, but also simplify the cooling structure design to a certain extent. It is considered to be one of the most practical ways to increase the operating temperature of various types of gas turbines.

[0003] Certain engine structural components feature narrow internal cavities and thin walls, making the preparation of internal thermal barrier coatings challenging. This narrow cavity requires the use of a small spray gun and a reduced spray distance. With a small gun barrel and a short spray distance, the reaction force generated by the plasma jet from the muzzle upon reaching the component wall can cause the gun to become unstable. Furthermore, thermal spraying within the inner bore environment rapidly accumulates heat within the enclosed space, and reducing the spray distance can also cause overheating of the component wall and the spray gun, making temperature control difficult and prone to deformation. Furthermore, the cylindrical structure makes it difficult to promptly discharge dust and exhaust gases generated during the spraying process. Due to the shortened spray distance, the powder cannot be fully heated and accelerated in the jet, resulting in a large number of semi-molten or unmelted particles. These particles easily rebound into the surrounding space upon impacting the substrate surface, forming inclusions during coating preparation. Overall, the spraying environment for narrow, thin-walled components is harsh, making coating preparation difficult and resulting in poor coating quality. Summary of the Invention

[0004] The technical problem solved by the present invention is: to overcome the shortcomings of the existing technology, and to propose a thermal barrier coating spraying device and method for the interior of a narrow inner cavity thin-walled component. The method can ensure stable spraying of the workpiece, solve the problems of unstable spray gun, powder particle rebound, and easy overheating and deformation of thin-walled parts during the process, the coating product meets the requirements, and production efficiency is improved.

[0005] The technical solution of the present invention is:

[0006] A thermal barrier coating spraying device for a narrow inner cavity thin-walled component, the spraying device comprising a spraying body and an exhaust dust removal device 9;

[0007] The spraying body includes a powder feeding device 1, two gun body stabilizing devices 2, two base cooling devices 3, a device to prevent powder rebound 4, a gas flow regulating valve 5, two fixed supports 6, a spray gun body 7, and a powder feeding pipe support 10;

[0008] The powder feeding device 1 is a round tube for feeding the spray powder into the spray gun body 7. The surface of the spray gun body 7 receiving the spray powder is a cross section of α = 30-60°; the surface of the spray gun body 7 that ejects the flame after receiving the spray powder is a cross section of 90-α°.

[0009] The gun body stabilizing device 2 is a circular tube with a circular hole on the side thereof for injecting compressed air. A gas flow regulating valve 5-2 is mounted on one end of the tube for adjusting the flow of the compressed air. The direction of the compressed air injection is perpendicular to the central axis of the spray gun body 7 and at an angle of 90+α° to the direction of the flame ejection. The purpose of injecting the compressed air is to offset the reaction force of the plasma flame flow.

[0010] The substrate cooling device 3 is a circular tube with a circular hole on its side for injecting compressed air. A gas flow control valve 5-3 is installed at one end of the tube to adjust the flow of compressed air. The direction of compressed air injection is perpendicular to the central axis of the spray gun body 7 and at an angle of 90°-α to the direction of the ejected flame. The purpose of injecting compressed air is to cool the narrow inner cavity thin-walled component 8 to be sprayed.

[0011] The powder rebound prevention device 4 includes a circular tube and a hollow circular tube integrally formed with one end of the circular tube. The side of the hollow circular tube has a circular hole for spraying compressed air, and the other end of the circular tube is equipped with a gas flow regulating valve 5-4 for regulating the flow of compressed air. The hollow circular tube is used to form a gas shielding curtain to prevent powder splashing and rebound, and the strength of the gas shielding curtain can be adjusted according to different spraying parameters.

[0012] The two fixed supports 6 are respectively a first support and a second support, and the first support and the second support are both a circular ring. The first support is sleeved on the outside of one side of the spray gun body 7, and the inner surface of the first support is in contact with the outer surface of the spray gun body 7. The second support is sleeved on the outside of the other side of the spray gun body 7, and the inner surface of the second support is in contact with the outer surface of the spray gun body 7.

[0013] The two gun body stabilizing devices 2 and the two base cooling devices 3 are all fixed circumferentially and axially by the first support and the second support;

[0014] One end of the powder feeding device 1 is fixed circumferentially and axially by the first support, and the other end of the powder feeding device 1 passes through the second support and is fixed by the powder feeding pipe support 10, which is fixedly connected to the spray gun body 7;

[0015] One end of the tube of the powder rebound prevention device 4 is fixed circumferentially and axially by the first support, and after the other end of the tube of the powder rebound prevention device 4 passes through the second support, the hollow circular ring tube of the powder rebound prevention device 4 is attached to the conical surface of the spray gun body 7;

[0016] The exhaust dust removal device 9 is located on one side of the narrow inner cavity thin-walled component 8 to be sprayed, and is 100-200 mm away from the upper surface of the narrow inner cavity thin-walled component 8 to be sprayed. The exhaust dust removal device 9 is an exhaust fan, which can extract some impurities and heat from the inner cavity of the narrow inner cavity thin-walled component 8 to be sprayed without affecting the spraying effect, thereby reducing pollution to the coating.

[0017] The powder feeding device 1 is used to transport bonding layer powder or ceramic surface layer powder, and coatings with different functions can be prepared by changing the type of powder fed into the pipeline.

[0018] A method for spraying a thermal barrier coating inside a thin-walled component with a narrow inner cavity, the method comprising the following steps:

[0019] Step 1: Place the spraying body in the cavity of the narrow inner cavity thin-walled component 8 to be sprayed, and place the exhaust dust removal device 9 on one side of the narrow inner cavity thin-walled component 8 to be sprayed;

[0020] Step 2: determining the spraying path when the powder feeding device 1 does not feed powder;

[0021] Step 3: preheating the inner cavity of the narrow inner cavity thin-walled component 8 to be sprayed;

[0022] Step 4: The bonding layer powder is delivered by the powder feeding device 1 and sprayed according to the spraying path determined in step 2 to obtain the bonding layer;

[0023] Step 5: The ceramic surface layer powder is delivered by the powder feeding device 1 and sprayed on the bonding layer according to the spraying path determined in step 2 to obtain the ceramic surface layer;

[0024] In the second step, the spraying path adopts a serpentine spraying path. After completing a spraying path, the spray gun moves 1-3 mm and continues to move. The spraying distance is 1-10 mm, and the spray gun moves at a speed of 100-500 mm / s. When the spray gun movement path covers the entire inner surface of the narrow inner cavity thin-walled component 8 to be sprayed, one cycle is completed.

[0025] In step 3, the preheating parameters are as follows: this process does not require the connection of a powder delivery pipeline, the main gas is argon, the flow rate is 10-50 L / min, the auxiliary gas is hydrogen, the flow rate is 1-5 L / min, the current is 100-800 A, the voltage is 10-50 V, the preheating number is 1-3 cycles, and the inner cavity temperature of the narrow inner cavity thin-walled component 8 to be sprayed is determined to be 100-300 degrees by an infrared temperature measuring gun;

[0026] In the step 4, the bonding layer powder is CoNiCrAlY powder, the main gas flow rate is 10-30 L / min, the auxiliary gas flow rate is 1-3 L / min, the carrier gas (argon) flow rate is 10-30 L / min, the powder feeding rate is 1-5 r / min, the current is 100-600 A, the voltage is 10-50 V, the compressed air flow rate of the gun body stabilization device 2 is 10-80 L / min, the compressed air flow rate of the base cooling device 3 is 1-30 L / min, the compressed air flow rate of the powder rebound prevention device 4 is 10-50 L / min, and the exhaust dust removal device 9 is kept running;

[0027] In the step five, the main gas flow rate is 10-30 L / min, the auxiliary gas flow rate is 1-3 L / min, the carrier gas flow rate is 10-30 L / min, the powder feeding rate is 1-5 r / min, the current is 200-800 A, the voltage is 20-50 V, the compressed air flow rate of the gun body stabilization device 2 is 10-80 L / min, the compressed air flow rate of the base cooling device 3 is 1-30 L / min, the compressed air flow rate of the powder rebound prevention device 4 is 10-50 L / min, and the exhaust dust removal device 9 remains in operation.

[0028] Beneficial effects

[0029] The present invention optimizes the structure of a plasma spray gun for spraying thermal barrier coatings, adopts a gun body stabilizing device to adjust the spray gun posture during the spraying process, and ensures the uniformity of the prepared coating; adopts a substrate cooling device for auxiliary cooling, reduces the deformation of the substrate during the spraying process, and controls the temperature of the workpiece during spraying; adopts a powder rebound prevention device to reduce impurities, and forms a gas shielding curtain by adjusting the gas discharge volume to prevent powder from splashing and rebounding; adopts an exhaust dust removal device to timely discharge dust and exhaust gas generated in the coating preparation process, and ensures that the coating is free of foreign matter during the preparation process; effectively ensures the stability of the coating preparation quality of the workpiece during the spraying process, reduces the degree of deformation of the workpiece during the spraying process, thereby improving the coating preparation quality, reducing the time used for coating preparation, greatly shortening the processing cycle of the workpiece, reducing the scrap rate of the workpiece, and increasing production efficiency, effectively ensuring production progress.

[0030] The present invention discloses a method for preparing a thermal barrier coating inside a thin-walled component with a narrow inner cavity. The preparation method improves plasma spray gun equipment, adjusts spraying process parameters, and is equipped with an exhaust dust removal device. A gun body stabilization device, a substrate cooling device, and a powder rebound prevention device are designed for the miniaturized plasma spray gun, thereby achieving the functions of stable spraying, substrate cooling, and shielding impurity powder. The exhaust dust removal device evacuates the inner cavity channel of the workpiece to remove impurities. The present invention can ensure stable spraying of the workpiece in a narrow inner cavity component, and solves the problems of spray gun instability, powder particle rebound, and easy overheating and deformation of thin-walled components during the process. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0032] Figure 2 It is a structural diagram of the back of the spray gun;

[0033] Figure 3 This is a partial enlarged view of the back structure of the spray gun;

[0034] Figure 4 It is a structural diagram of the front of the spray gun;

[0035] Figure 5 This is a partial enlarged view of the front structure of the spray gun;

[0036] Figure 6 Schematic diagram of jet direction;

[0037] Figure 7 This is a backscattered photo of a single-layer thermal barrier coating structure;

[0038] Figure 8 Backscattered photos and element distribution results of the double-layer thermal barrier coating structure. DETAILED DESCRIPTION

[0039] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0040] Example 1

[0041] like Figure 1-Figure 5 As shown, a thermal barrier coating spraying device for the interior of a narrow inner cavity thin-walled component includes a spraying body and an exhaust dust removal device 9;

[0042] The spraying body includes a powder feeding device 1, two gun body stabilizing devices 2, two base cooling devices 3, a device to prevent powder rebound 4, a gas flow regulating valve 5, two fixed supports 6, a spray gun body 7, and a powder feeding pipe support 10;

[0043] The powder feeding device 1 is a round tube for feeding the spray powder into the spray gun body 7, and the surface of the spray gun body 7 receiving the spray powder is a 30° section; the surface of the spray gun body 7 that ejects the flame after receiving the spray powder is a 60° section. Figure 6 As shown;

[0044] The gun body stabilizing device 2 is a circular tube with a circular hole on the side thereof for injecting compressed air. A gas flow regulating valve 5-2 is mounted on one end of the tube for adjusting the flow of the compressed air. The direction of the compressed air injection is perpendicular to the central axis of the spray gun body 7 and at an angle of 120° to the direction of the flame ejection. The purpose of injecting the compressed air is to offset the reaction force of the plasma flame flow.

[0045] The substrate cooling device 3 is a circular tube with a circular hole on the side for injecting compressed air. A gas flow control valve 5-3 is installed at one end of the tube to adjust the flow of compressed air. The direction of compressed air injection is perpendicular to the central axis of the spray gun body 7 and at an angle of 60° to the direction of the ejected flame. The purpose of injecting compressed air is to cool the narrow inner cavity thin-walled component 8 to be sprayed.

[0046] The powder rebound prevention device 4 includes a circular tube and a hollow circular tube integrally formed with one end of the circular tube. The side of the hollow circular tube has a circular hole for spraying compressed air, and the other end of the circular tube is equipped with a gas flow regulating valve 5-4 for regulating the flow of compressed air. The hollow circular tube is used to form a gas shielding curtain to prevent powder splashing and rebound, and the strength of the gas shielding curtain can be adjusted according to different spraying parameters.

[0047] The two fixed supports 6 are respectively a first support and a second support, and the first support and the second support are both a circular ring. The first support is sleeved on the outside of one side of the spray gun body 7, and the inner surface of the first support is in contact with the outer surface of the spray gun body 7. The second support is sleeved on the outside of the other side of the spray gun body 7, and the inner surface of the second support is in contact with the outer surface of the spray gun body 7.

[0048] The two gun body stabilizing devices 2 and the two base cooling devices 3 are all fixed circumferentially and axially by the first support and the second support;

[0049] One end of the powder feeding device 1 is fixed circumferentially and axially by the first support, and the other end of the powder feeding device 1 passes through the second support and is fixed by the powder feeding pipe support 10, which is fixedly connected to the spray gun body 7;

[0050] One end of the tube of the powder rebound prevention device 4 is fixed circumferentially and axially by the first support, and after the other end of the tube of the powder rebound prevention device 4 passes through the second support, the hollow circular ring tube of the powder rebound prevention device 4 is attached to the conical surface of the spray gun body 7;

[0051] The exhaust and dust removal device 9 is located on one side of the narrow inner cavity thin-walled component 8 to be sprayed, and is 200 mm away from the upper surface of the narrow inner cavity thin-walled component 8 to be sprayed. The exhaust and dust removal device 9 is an exhaust fan, which can extract some impurities and heat from the inner cavity of the narrow inner cavity thin-walled component 8 to be sprayed without affecting the spraying effect, thereby reducing pollution to the coating.

[0052] The powder feeding device 1 is used to transport bonding layer powder or ceramic surface layer powder, and coatings with different functions can be prepared by changing the type of powder fed into the pipeline.

[0053] A method for spraying a thermal barrier coating inside a thin-walled component with a narrow inner cavity, the method comprising the following steps:

[0054] Step 1: Place the spraying body in the cavity of the narrow inner cavity thin-walled component 8 to be sprayed, and place the exhaust dust removal device 9 on one side of the narrow inner cavity thin-walled component 8 to be sprayed;

[0055] Step 2: determining the spraying path when the powder feeding device 1 does not feed powder;

[0056] Step 3: preheating the inner cavity of the narrow inner cavity thin-walled component 8 to be sprayed;

[0057] Step 4: The bonding layer powder is delivered by the powder feeding device 1 and sprayed according to the spraying path determined in step 2 to obtain the bonding layer;

[0058] Step 5: The ceramic surface layer powder is delivered by the powder feeding device 1 and sprayed on the bonding layer according to the spraying path determined in step 2 to obtain the ceramic surface layer;

[0059] In the second step, the spraying path is a serpentine spraying path. After completing one spraying path, the spray gun moves 3 mm and continues to move. The spraying distance is 10 mm and the movement speed of the spray gun is 500 mm / s. When the movement path of the spray gun covers the entire inner surface of the narrow inner cavity thin-walled component 8 to be sprayed, one cycle is completed.

[0060] In step 3, the preheating parameters are as follows: this process does not require the connection of a powder feeding pipeline, the main gas is argon, the flow rate is 50 L / min, the auxiliary gas is hydrogen, the flow rate is 5 L / min, the current is 600 A, the voltage is 50 V, the preheating number is 1 cycle, and the inner cavity temperature of the narrow inner cavity thin-walled component 8 to be sprayed is determined to be 200 degrees by an infrared temperature measuring gun;

[0061] In the step 4, the bonding layer powder is CoNiCrAlY powder, the main gas flow rate is 30 L / min, the auxiliary gas flow rate is 3 L / min, the carrier gas (argon) flow rate is 30 L / min, the powder feeding rate is 5 r / min, the current is 600 A, the voltage is 50 V, the compressed air flow rate of the gun body stabilization device 2 is 60 L / min, the compressed air flow rate of the base cooling device 3 is 10 L / min, the compressed air flow rate of the powder rebound prevention device 4 is 20 L / min, and the exhaust dust removal device 9 is kept in operation;

[0062] In the step five, ZrO2 powder is introduced into the powder feeding pipeline 1, the main gas flow rate is 30L / min, the auxiliary gas flow rate is 3L / min, the carrier gas flow rate is 20L / min, the powder feeding rate is 3r / min, the current is 700A, the voltage is 30V, the gun body stabilization device 2 gas flow rate is 60L / min, the base cooling device 3 gas flow rate is 10L / min, the powder rebound prevention device 4 gas flow rate is 30L / min, and the exhaust dust removal device 9 remains in operation.

[0063] The backscattering photography of the single-layer thermal barrier coating structure of the narrow inner cavity thin-walled component after spraying is carried out, such as Figure 7 As shown by Figure 7 It can be seen that the interfaces among the substrate, bonding layer and ceramic surface layer are well bonded, the thickness of the bonding layer and the ceramic surface layer are uniform, the pores in the ceramic surface layer are evenly distributed, and no obvious impurities and unmelted particles are observed.

[0064] Example 2

[0065] A method for spraying a thermal barrier coating inside a thin-walled component with a narrow inner cavity, the method comprising the following steps:

[0066] Step 1: Place the spraying body in the cavity of the narrow inner cavity thin-walled component 8 to be sprayed, and place the exhaust dust removal device 9 on one side of the narrow inner cavity thin-walled component 8 to be sprayed;

[0067] Step 2: determining the spraying path when the powder feeding device 1 does not feed powder;

[0068] Step 3: preheating the inner cavity of the narrow inner cavity thin-walled component 8 to be sprayed;

[0069] Step 4: The bonding layer powder is delivered by the powder feeding device 1 and sprayed according to the spraying path determined in step 2 to obtain the bonding layer;

[0070] Step 5: ceramic surface layer powder 1# is delivered by powder feeding device 1 and sprayed on the bonding layer according to the spraying path determined in step 2 to obtain ceramic surface layer 1#;

[0071] Step 6: Ceramic surface layer powder 2# is delivered by powder feeding device 1 and sprayed on ceramic surface layer 1# according to the spraying path determined in step 2 to obtain ceramic surface layer 2#;

[0072] In the second step, the spraying path is a serpentine spraying path. After completing one spraying path, the spray gun moves 2 mm and continues to move. The spraying distance is 8 mm and the movement speed of the spray gun is 500 mm / s. When the movement path of the spray gun covers the entire inner surface of the narrow inner cavity thin-walled component 8 to be sprayed, one cycle is completed.

[0073] In step 3, the preheating parameters are as follows: this process does not require the connection of a powder feeding pipeline, the main gas is argon, the flow rate is 50 L / min, the auxiliary gas is hydrogen, the flow rate is 5 L / min, the current is 600 A, the voltage is 50 V, the preheating number is 1 cycle, and the inner cavity temperature of the narrow inner cavity thin-walled component 8 to be sprayed is determined to be 150 degrees by an infrared temperature measuring gun;

[0074] In the step 4, the bonding layer powder is CoNiCrAlY powder, the main gas flow rate is 20 L / min, the auxiliary gas flow rate is 3 L / min, the carrier gas (argon) flow rate is 20 L / min, the powder feeding rate is 5 r / min, the current is 700 A, the voltage is 50 V, the compressed air flow rate of the gun body stabilization device 2 is 60 L / min, the compressed air flow rate of the base cooling device 3 is 20 L / min, the compressed air flow rate of the powder rebound prevention device 4 is 20 L / min, and the exhaust dust removal device 9 is kept in operation;

[0075] In the step 5, Y2O3-stabilized ZrO2 powder is introduced into the powder feeding pipeline 1, the main gas flow rate is 30L / min, the auxiliary gas flow rate is 3L / min, the carrier gas flow rate is 20L / min, the powder feeding rate is 3r / min, the current is 800A, the voltage is 30V, the gas flow rate of the gun body stabilization device 2 is 80L / min, the gas flow rate of the substrate cooling device 3 is 20L / min, the gas flow rate of the powder rebound prevention device 4 is 40L / min, and the exhaust dust removal device 9 is kept in operation;

[0076] In the step six, Gd2O3, Yb2O3 and Y2O3 co-stabilized ZrO2 powders are introduced into the powder feeding pipeline 1, the main gas flow rate is 40L / min, the auxiliary gas flow rate is 3L / min, the carrier gas flow rate is 20L / min, the powder feeding rate is 3r / min, the current is 850A, the voltage is 30V, the gas flow rate of the gun body stabilization device 2 is 80L / min, the gas flow rate of the base cooling device 3 is 10L / min, the gas flow rate of the powder rebound prevention device 4 is 50L / min, and the exhaust dust removal device 9 remains in operation.

[0077] Figure 8 The backscattered photos and element distribution results of the double-layer thermal barrier coating structure prepared by an improved spray gun show that the interfaces of the substrate, bonding layer, ceramic surface layer 1# and ceramic surface layer 2# are well bonded, the thickness of the bonding layer, ceramic surface layer 1# and ceramic surface layer 2# are uniform, and the elements in ceramic surface layer 1# and ceramic surface layer 2# are evenly distributed without obvious aggregation.

[0078] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A thermal barrier coating spraying device for a narrow inner cavity thin-walled component, characterized in that: The spraying device comprises a spraying body and an exhaust dust removal device (9); The spraying body includes a powder feeding device (1), two gun body stabilizing devices (2), two base cooling devices (3), a powder rebound prevention device (4), a gas flow regulating valve, two fixed supports (6), a spray gun body (7), and a powder feeding pipe support (10); The powder feeding device (1) is a round tube for feeding the spray powder into the spray gun body (7); The gun body stabilizing device (2) is a round tube with a round hole on the side of the round tube for spraying compressed air, and a gas flow regulating valve is installed at one end of the round tube for regulating the flow of compressed air; The substrate cooling device (3) is a circular tube with a circular hole on the side of the circular tube for spraying compressed air, and a gas flow regulating valve is installed at one end of the circular tube for regulating the flow of the compressed air; The powder rebound prevention device (4) comprises a circular tube and a hollow circular ring tube integrally formed with one end of the circular tube, wherein a circular hole is provided on the side of the hollow circular ring tube for injecting compressed air, and a gas flow regulating valve is installed at the other end of the circular tube for regulating the flow of the compressed air; The two fixed supports (6) are respectively a first support and a second support, the first support and the second support are both a circular ring, the first support is sleeved on the outside of one side of the spray gun body (7), and the inner surface of the first support is in contact with the outer surface of the spray gun body (7), and the second support is sleeved on the outside of the other side of the spray gun body (7), and the inner surface of the second support is in contact with the outer surface of the spray gun body (7); The two gun body stabilizing devices (2) and the two base cooling devices (3) are all fixed circumferentially and axially via the first support and the second support; One end of the powder feeding device (1) is fixed circumferentially and axially by a first support, and the other end of the powder feeding device (1) passes through a second support and is fixed by a powder feeding pipe support (10), and the powder feeding pipe support (10) is fixedly connected to the spray gun body (7); One end of the circular tube of the device for preventing powder rebound (4) is fixed circumferentially and axially by a first support, and after the other end of the circular tube of the device for preventing powder rebound (4) passes through a second support, the hollow circular ring tube of the device for preventing powder rebound (4) is attached to the end face of the spray gun body (7); The exhaust dust removal device (9) is located on one side of the narrow inner cavity thin-walled component (8) to be sprayed.

2. The thermal barrier coating spraying device for the interior of a narrow inner cavity thin-walled component according to claim 1, characterized in that: The surface of the spray gun body (7) that receives the spray powder is a section with an angle of α = 30-60°; The surface of the spray gun body (7) that receives the spray powder and sprays the flame is a 90-α° section.

3. The thermal barrier coating spraying device for the interior of a narrow cavity thin-walled component according to claim 1, characterized in that: The direction in which the gun body stabilizing device (2) sprays compressed air is perpendicular to the central axis of the spray gun body (7) and has an angle of 90°+α with the direction in which the flame is sprayed.

4. The thermal barrier coating spraying device for the interior of a narrow inner cavity thin-walled component according to claim 1, characterized in that: The direction in which the base cooling device (3) sprays compressed air is perpendicular to the central axis of the spray gun body (7) and has an angle of 90°-α with the direction in which the flame is sprayed.

5. The thermal barrier coating spraying device for the interior of a thin-walled component with a narrow inner cavity according to claim 1, characterized in that: The distance between the exhaust dust removal device (9) and the upper surface of the narrow inner cavity thin-walled component (8) to be sprayed is 100-200 mm.

6. A method for spraying thermal barrier coatings on the interior of thin-walled components with narrow cavities using the device according to claim 1, characterized in that The steps of the method include: Step 1: Place the spraying body in the cavity of the narrow inner cavity thin-walled component to be sprayed, and place the exhaust dust removal device on one side of the narrow inner cavity thin-walled component to be sprayed; Step 2: determining the spraying path when the powder feeding device does not feed powder; Step 3: preheating the inner cavity of the narrow inner cavity thin-walled component to be sprayed; Step 4: transport the bonding layer powder through the powder feeding device and spray it according to the spraying path determined in step 2 to obtain the bonding layer; Step 5: The ceramic surface layer powder is transported by a powder feeding device and sprayed on the bonding layer according to the spraying path determined in step 2 to obtain a ceramic surface layer.

7. The method for spraying thermal barrier coating on the inside of a thin-walled component with a narrow inner cavity according to claim 6, characterized in that: In the second step, the spraying path is a serpentine spraying path. After completing one spraying path, the spraying path is moved horizontally 1-3 mm and then continues to move. The spraying distance is 1-10 mm, and the spray gun movement speed is 100-500 mm / s. When the spray gun movement path covers the entire inner surface of the narrow inner cavity thin-walled component (8) to be sprayed, it is considered one cycle.

8. The method for spraying thermal barrier coating on the inside of a thin-walled component with a narrow inner cavity according to claim 7, characterized in that: In step 3, the preheating parameters are as follows: the process does not require the connection of a powder delivery pipeline, the main gas is argon, the flow rate is 10-50 L / min, the auxiliary gas is hydrogen, the flow rate is 1-5 L / min, the current is 100-800 A, the voltage is 10-50 V, the preheating number is 1-3 cycles, and the inner cavity temperature of the narrow inner cavity thin-walled component (8) to be sprayed is determined to be 100-300 degrees by an infrared temperature measuring gun.

9. The method for spraying thermal barrier coating on the inside of a thin-walled component with a narrow inner cavity according to claim 8, characterized in that: In the step 4, the bonding layer powder is CoNiCrAlY powder, the main gas flow rate is 10-30 L / min, the auxiliary gas flow rate is 1-3 L / min, the carrier gas flow rate is 10-30 L / min, the powder feeding rate is 1-5 r / min, the current is 100-600 A, the voltage is 10-50 V, the compressed air flow rate of the gun body stabilization device is 10-80 L / min, the compressed air flow rate of the substrate cooling device is 1-30 L / min, the compressed air flow rate of the powder rebound prevention device is 10-50 L / min, and the exhaust dust removal device remains in operation.

10. The method for spraying thermal barrier coating inside a thin-walled component with a narrow inner cavity according to claim 9, characterized in that: In the step 5, the main gas flow rate is 10-30 L / min, the auxiliary gas flow rate is 1-3 L / min, the carrier gas flow rate is 10-30 L / min, the powder feeding rate is 1-5 r / min, the current is 200-800 A, the voltage is 20-50 V, the compressed air flow rate of the gun body stabilization device is 10-80 L / min, the compressed air flow rate of the base cooling device is 1-30 L / min, the compressed air flow rate of the powder rebound prevention device is 10-50 L / min, and the exhaust dust removal device remains in operation.

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