Preparation method of thermal barrier coating inside thin-wall component with narrow inner cavity

Abstract

The invention relates to a spraying device and method for a thermal barrier coating in a thin-wall component with a narrow inner cavity, and belongs to the technical field of spraying preparation methods and advanced machining of deformation control. A gun body stabilizing device is adopted for adjusting the posture of a spray gun in the spraying process, and the uniformity of the prepared coating is guaranteed; a matrix cooling device is adopted for auxiliary cooling, the deformation amount of a matrix in the spraying process is reduced, and the temperature of a workpiece in the spraying process is controlled; a device for preventing powder from rebounding is adopted to reduce impurities, a gas shielding curtain is formed by adjusting the discharge amount of gas, and powder is prevented from splashing and rebounding; an air draft dust removal device is adopted, dust and waste gas generated in the coating preparation process can be discharged in time, and it is ensured that no foreign matter is mixed in the coating preparation process; the stability of the coating preparation quality in the spraying process of the workpiece is effectively guaranteed, the deformation degree of the workpiece in the spraying process is reduced, the coating preparation quality is improved, and the coating preparation time is shortened.

Description

Technical Field

[0001] The invention relates to a device and method for spraying thermal barrier coating inside a narrow inner cavity thin-wall component, belonging to the advanced processing technology field 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 increased. 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] A certain type of engine structural part has the characteristics of narrow inner cavity and thin wall, and the preparation of its internal thermal barrier coating is difficult. The narrow inner cavity requires the use of a small spray gun and a reduced spraying distance. Under the conditions of a small gun body and a close spraying distance, the reaction force generated by the plasma jet at the muzzle after reaching the component wall will cause the gun body to be unstable; in addition, when thermal spraying is performed in an inner hole environment, the heat in the closed space accumulates quickly, and reducing the spraying distance may also cause the component wall and the spray gun to overheat, the temperature is difficult to control, and deformation problems are prone to occur; in addition, the cylindrical structure makes it difficult to discharge the dust and exhaust gas generated during the spraying process in time. Due to the shortened spraying 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 are easy to rebound into the surrounding space after hitting the substrate surface, forming inclusion particles during coating preparation. In general, the spraying environment of narrow inner cavity thin-walled parts is harsh, the coating preparation of the product is difficult, and the coating quality is poor. Summary of the invention

[0004] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art and to propose a device and method for spraying thermal barrier coatings inside thin-walled components with narrow inner cavities. The method can ensure stable spraying of the workpiece, solve the problems of unstable spray guns, powder particle rebound, and easy overheating and deformation of thin-walled components during the process, the coating products meet the requirements, and the 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 powder rebound prevention device 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, which is used to feed the spray powder into the spray gun body 7, and the surface of the spray gun body 7 receiving the spray powder is a section with α=30-60°; the surface of the spray gun body 7 spraying the flame after receiving the spray powder is a section with 90-α°;

[0009] 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 5-2 is installed at one end of the round tube for regulating the flow of compressed air; the direction of spraying compressed air is perpendicular to the central axis of the spray gun body 7 and the angle with the direction of the sprayed flame is 90+α°; the purpose of spraying compressed air is to offset the reaction force of the plasma flame flow;

[0010] The substrate cooling device 3 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 5-3 is installed at one end of the round tube for regulating the flow of compressed air; the direction of spraying compressed air is perpendicular to the central axis of the spray gun body 7 and the angle with the direction of the spraying flame is 90°-α; the purpose of spraying compressed air is to cool the narrow inner cavity thin-walled component 8 to be sprayed;

[0011] The device 4 for preventing powder rebound comprises a round tube and a hollow circular ring tube integrally formed with one end of the round tube, the side of the hollow circular ring tube is provided with a circular hole for spraying compressed air, and the other end of the round tube is provided with a gas flow regulating valve 5-4 for regulating the flow of compressed air; the hollow circular ring tube is used to form a gas shielding curtain to prevent the splashing and rebound of powder, 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, 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;

[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, and the powder feeding pipe support 10 is fixedly connected to the spray gun body 7;

[0015] One end of the round tube of the powder rebound prevention device 4 is fixed circumferentially and axially through the first support, and after the other end of the round 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 100-200mm 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 thermal barrier coating inside a narrow inner cavity thin-walled component, the method comprising the steps of:

[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: convey the bonding layer powder through the powder feeding device 1, and spray it according to the spraying path determined in step 2 to obtain the bonding layer;

[0023] Step 5: conveying ceramic surface layer powder through the powder feeding device 1, and spraying it on the bonding layer according to the spraying path determined in step 2 to obtain a ceramic surface layer;

[0024] In the step 2, the spraying path is 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 moves to cover the entire inner surface of the narrow inner cavity thin-walled component 8 to be sprayed, it is considered one cycle.

[0025] In the step 3, the preheating parameters are as follows: the process does not require the connection of the powder delivery pipeline, the main gas is argon, the flow rate is 10-50L / min, the auxiliary gas is hydrogen, the flow rate is 1-5L / min, the current is 100-800A, the voltage is 10-50V, 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 10-30L / min, the auxiliary gas flow rate is 1-3L / min, the carrier gas (argon) flow rate is 10-30L / min, the powder feeding rate is 1-5r / min, the current is 100-600A, the voltage is 10-50V, the compressed air flow rate of the gun body stabilizing device 2 is 10-80L / min, the compressed air flow rate of the substrate cooling device 3 is 1-30L / min, the compressed air flow rate of the powder rebound prevention device 4 is 10-50L / min, and the exhaust dust removal device 9 keeps running;

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

[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 posture of the spray gun 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 amount to prevent powder splashing and rebounding; adopts an exhaust dust removal device to timely discharge dust and waste gas generated during 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 deformation degree of the workpiece during the spraying process, improves the coating preparation quality, reduces the time used for coating preparation, greatly shortens the processing cycle of the workpiece, reduces the scrap rate of the workpiece, achieves the effect of increasing production efficiency, and effectively guarantees the production progress.

[0030] The invention discloses a method for preparing a thermal barrier coating inside a narrow inner cavity thin-walled component. The preparation method improves plasma spray gun equipment, adjusts spraying process parameters and is equipped with an exhaust dust removal device; a gun body stabilizing device, a substrate cooling device and a powder rebound prevention device are designed for a miniaturized plasma spray gun, thereby realizing the functions of stable spraying, substrate cooling and impurity powder shielding; the exhaust dust removal device evacuates the inner cavity channel of the workpiece to remove impurities; the invention can ensure stable spraying of the workpiece in a narrow inner cavity component, thereby solving the problems of unstable spray gun, rebound of powder particles and easy overheating and deformation of thin-walled components in 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 schematic diagram of the structure on 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 schematic 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 It is a schematic diagram of the 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, the spraying device comprises 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 powder rebound prevention device 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 sprays the flame after receiving the spray powder is a 60° section. Figure 6 As shown;

[0044] 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 5-2 is installed at one end of the round tube for regulating the flow of compressed air; the direction of spraying compressed air is perpendicular to the central axis of the spray gun body 7 and the angle with the direction of the spraying flame is 120°; the purpose of spraying compressed air is to offset the reaction force of the plasma flame flow;

[0045] The substrate cooling device 3 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 5-3 is installed at one end of the round tube for regulating the flow of compressed air; the direction of spraying compressed air is perpendicular to the central axis of the spray gun body 7 and the angle with the direction of the spraying flame is 60°; the purpose of spraying compressed air is to cool the narrow inner cavity thin-walled component 8 to be sprayed;

[0046] The device 4 for preventing powder rebound comprises a round tube and a hollow circular ring tube integrally formed with one end of the round tube, the side of the hollow circular ring tube is provided with a circular hole for spraying compressed air, and the other end of the round tube is provided with a gas flow regulating valve 5-4 for regulating the flow of compressed air; the hollow circular ring tube is used to form a gas shielding curtain to prevent the splashing and rebound of powder, 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, 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;

[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, and the powder feeding pipe support 10 is fixedly connected to the spray gun body 7;

[0050] One end of the round tube of the powder rebound prevention device 4 is fixed circumferentially and axially through the first support, and after the other end of the round 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 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 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 thermal barrier coating inside a narrow inner cavity thin-walled component, the method comprising the steps of:

[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: convey the bonding layer powder through the powder feeding device 1, and spray it according to the spraying path determined in step 2 to obtain the bonding layer;

[0058] Step 5: conveying ceramic surface layer powder through the powder feeding device 1, and spraying it on the bonding layer according to the spraying path determined in step 2 to obtain a ceramic surface layer;

[0059] In the step 2, 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 spray gun moves at a speed of 500 mm / s. When the spray gun moves to cover the entire inner surface of the narrow inner cavity thin-walled component 8 to be sprayed, it is considered one cycle.

[0060] In the step 3, the preheating parameters are as follows: the process does not require the connection of the powder delivery pipeline, the main gas is argon, the flow rate is 50L / min, the auxiliary gas is hydrogen, the flow rate is 5L / min, the current is 600A, the voltage is 50V, 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 30L / min, the auxiliary gas flow rate is 3L / min, the carrier gas (argon) flow rate is 30L / min, the powder feeding rate is 5r / min, the current is 600A, the voltage is 50V, the compressed air flow rate of the gun body stabilizing device 2 is 60L / min, the compressed air flow rate of the substrate cooling device 3 is 10L / min, the compressed air flow rate of the powder rebound prevention device 4 is 20L / min, and the exhaust dust removal device 9 keeps running;

[0062] In the step five, ZrO2 powder is introduced into the powder delivery 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 delivery rate is 3r / min, the current is 700A, the voltage is 30V, the gas flow rate of the gun body stabilizing device 2 is 60L / min, the gas flow rate of the substrate cooling device 3 is 10L / min, the gas flow rate of the powder rebound prevention device 4 is 30L / min, and the exhaust dust removal device 9 is kept running.

[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 interface bonding between the substrate, the bonding layer and the ceramic surface layer is good, the thickness of the bonding layer and the ceramic surface layer is uniform, the pores in the ceramic surface layer are evenly distributed, and no obvious impurities and unmelted particles are found.

[0064] Example 2

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

[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: convey the bonding layer powder through the powder feeding device 1, and spray it according to the spraying path determined in step 2 to obtain the bonding layer;

[0070] Step 5: conveying ceramic surface layer powder 1# through the powder feeding device 1, and spraying it on the bonding layer according to the spraying path determined in step 2 to obtain ceramic surface layer 1#;

[0071] Step 6: conveying ceramic surface layer powder 2# through powder feeding device 1, and spraying on ceramic surface layer 1# according to the spraying path determined in step 2, to obtain ceramic surface layer 2#;

[0072] In the step 2, 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 spray gun moves at a speed of 500 mm / s. When the spray gun moves to cover the entire inner surface of the narrow inner cavity thin-walled component 8 to be sprayed, it is considered one cycle.

[0073] In the step 3, the preheating parameters are as follows: the process does not require the connection of the powder delivery pipeline, the main gas is argon, the flow rate is 50L / min, the auxiliary gas is hydrogen, the flow rate is 5L / min, the current is 600A, the voltage is 50V, 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 20L / min, the auxiliary gas flow rate is 3L / min, the carrier gas (argon) flow rate is 20L / min, the powder feeding rate is 5r / min, the current is 700A, the voltage is 50V, the compressed air flow rate of the gun body stabilizing device 2 is 60L / min, the compressed air flow rate of the substrate cooling device 3 is 20L / min, the compressed air flow rate of the powder rebound prevention device 4 is 20L / min, and the exhaust dust removal device 9 keeps running;

[0075] In the step 5, Y2O3 stabilized ZrO2 powder is introduced into the powder delivery 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 delivery rate is 3r / min, the current is 800A, the voltage is 30V, the gas flow rate of the gun body stabilizing 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 running;

[0076] In the step six, Gd2O3, Yb2O3 and Y2O3 are introduced into the powder delivery pipeline 1 to co-stabilize ZrO2 powder, 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 delivery rate is 3r / min, the current is 850A, the voltage is 30V, the gas flow rate of the gun body stabilizing device 2 is 80L / min, the gas flow rate of the substrate 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 is kept running.

[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 protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope 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 comprises 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 used to feed 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 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 powder rebound prevention device (4) comprises a round tube and a hollow circular ring tube integrally formed with one end of the round tube, the side of the hollow circular ring tube is provided with a circular hole for spraying compressed air, and the other end of the round tube is provided with a gas flow regulating valve for regulating the flow of 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 a first support and a second support; One end of the powder delivery device (1) is fixed circumferentially and axially by a first support, and the other end of the powder delivery device (1) passes through a second support and is fixed by a powder delivery pipe support (10), and the powder delivery pipe support (10) is fixedly connected to the spray gun body (7); One end of the round 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 round 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 surface 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 inner part of a narrow inner cavity thin-walled component according to claim 1, characterized in that: The surface of the spray gun body (7) receiving 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 out the flame is a 90-α° section.

3. The thermal barrier coating spraying device for the inner part of a narrow inner 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 the angle between the compressed air and the direction in which the flame is sprayed is 90°+α.

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 the angle between the compressed air and the direction in which the flame is sprayed is 90°-α.

5. 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 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 coating inside a narrow inner cavity thin-walled component, characterized in that The steps of the method include: Step 1: placing the spraying body in the cavity of the narrow inner cavity thin-walled component to be sprayed, and placing 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: conveying the bonding layer powder through a powder feeding device and spraying it according to the spraying path determined in step 2 to obtain a bonding layer; Step 5: convey the ceramic surface layer powder through the powder feeding device, and spray it on the bonding layer according to the spraying path determined in step 2 to obtain the ceramic surface layer.

7. The method for spraying thermal barrier coating inside a narrow inner cavity thin-walled component according to claim 6, characterized in that: In the step 2, the spraying path adopts a serpentine spraying path. After completing a spraying path, it moves horizontally 1-3mm and continues to move. The spraying distance is 1-10mm, and the spray gun moves at a speed of 100-500mm / s. When the spray gun moves to cover the entire inner surface of the narrow inner cavity thin-walled component 8 to be sprayed, it is one cycle.

8. The method for spraying thermal barrier coating inside a narrow inner cavity thin-walled component according to claim 7, characterized in that: In the step three, the preheating parameters are: this process does not require the connection of the powder delivery pipeline, the main gas is argon, the flow rate is 10-50L / min, the auxiliary gas is hydrogen, the flow rate is 1-5L / min, the current is 100-800A, the voltage is 10-50V, 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 inside a narrow inner cavity thin-walled component according to claim 8, characterized in that: In the step 4, the bonding layer powder is CoNiCrAlY powder, the main gas flow rate is 10-30L / min, the auxiliary gas flow rate is 1-3L / min, the carrier gas flow rate is 10-30L / min, the powder feeding rate is 1-5r / min, the current is 100-600A, the voltage is 10-50V, the compressed air flow rate of the gun body stabilization device is 10-80L / min, the compressed air flow rate of the substrate cooling device is 1-30L / min, the compressed air flow rate of the powder rebound prevention device is 10-50L / min, and the exhaust dust removal device remains in operation.

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

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