A multi-ply guide vane corrosion-resistant thermal barrier coating plating method

Abstract

The present application belongs to the field of aviation metal material plating technology, and particularly relates to a kind of multi-assembly guide vane corrosion-resistant thermal barrier coating plating method. Zirconium oxide ceramic pellets are used for sandblasting pretreatment to optimize the surface profile, avoid particle embedding into the matrix, and enhance the adhesion of the coating. Secondly, a special coating clamp is used to achieve rapid positioning and clamping of the vane, ensuring uniformity of the spray. Finally, a supersonic flame spray is used to prepare a NiCoCrAlYHfSi metal bond layer, and combined with atmospheric plasma spraying, a YSZ and GdPO4 double-layer ceramic surface layer is sequentially plated to form a synergistic protective structure. Through material, process and tooling innovation, the present application solves the problem of multi-assembly vane coating, significantly improves the reliability, durability and process efficiency of the coating, and is suitable for long-life service requirements of aeroengines, having important industrial application value.

Description

Technical Field

[0001] This invention belongs to the field of aerospace metal material coating technology, specifically relating to a method for coating a corrosion-resistant thermal barrier coating on multi-section guide vanes. Background Technology

[0002] Aero-engines are the core components of aircraft power systems, and their performance directly affects flight safety and efficiency. Turbine blades, as critical engine components, endure the impact, erosion, and thermal cycling of high-temperature exhaust gases over extended periods, operating in extremely harsh environments. To ensure high reliability and long service life, turbine blade surfaces must be coated with thermal barrier coatings to reduce substrate temperature and resist oxidation and corrosion. However, as aero-engines develop towards higher thrust-to-weight ratios and longer service lifespans, the failure problems of traditional thermal barrier coatings under complex operating conditions are becoming increasingly prominent. In particular, the unique structure of multi-stage guide vanes further exacerbates the challenges of coating application.

[0003] Thermal barrier coatings typically consist of a metallic binder layer (such as MCrAIY, where M is Ni or Co) and a ceramic topcoat layer (such as 7-8 wt.% Y₂O₃ partially stabilized ZrO₂, i.e., YSZ). The metallic binder layer provides oxidation resistance and adhesion, while the ceramic topcoat layer primarily serves as thermal insulation. However, in actual service, coatings face various failure factors: the YSZ ceramic layer undergoes a phase transformation under prolonged high temperatures, leading to volume changes and crack initiation; excessive growth of the TGO layer formed at the interface between the binder layer and the substrate causes stress concentration and spalling; when aircraft operate in desert routes or volcanic ash environments, gravel, dust, etc., are sucked into the engine and melt under the high temperatures of the combustion chamber, forming molten CMAS composed of CaO, MgO, Al₂O₃, and SiO₂. CMAS deposits on the coating surface, wetting and penetrating the coating pores and microcracks in the molten state, reacting chemically with the coating, and altering its phase structure and properties. After solidification, CMAS also reduces the coating's thermal insulation performance and strain tolerance, accelerating coating failure. The changes on the coating surface after being eroded by the molten material highlight the severity of the CMAS problem.

[0004] Multi-section guide vanes, which integrate multiple blades with inner and outer rings through casting or welding, improve structural integrity but also introduce unique challenges: narrow, deep channels form between the blades, making it difficult for the coating to be evenly covered in the central part of the blade (especially the root area at the base and underside of the blade), resulting in uneven coating thickness and weak adhesion. Traditional sandblasting processes use white corundum sand, whose particles are easily broken and embedded in the matrix, affecting the integrity of the single-crystal material; furthermore, existing spraying technologies cannot effectively cover complex geometries, limiting the reliability and lifespan of the coating.

[0005] Domestic and international researchers have conducted extensive work on the corrosion problem of CMAS (Complex Cell Alkyl Asphaltene), proposing various improvement schemes, but all have significant drawbacks. For example, the YSZ+Al2O3+TiO2 coating proposed by Ohio State University in the United States slows down penetration by promoting CMAS crystallization. However, the additives increase the thermal conductivity of the coating, degrade its mechanical properties, and the problem of CMAS penetration is not fundamentally solved, with corrosion intensifying over time. Another example is the Pt coating used by Beijing University of Aeronautics and Astronautics, which physically blocks CMAS. However, the Pt layer becomes discontinuous under prolonged high temperatures, losing its protective effect. Other effective coatings include Gd2Zr2O7, La2Ce2O7, and LaMgAl. 11 O 19 Although these materials can block CMAS through the interface reaction layer, they come at the cost of coating thickness loss (for example, the thickness of the Gd2Zr2O7 coating decreased sharply from 750μm to 310μm after 40h of CMAS action), making it difficult to meet the requirements for long lifespan.

[0006] In summary, current thermal barrier coating structures and plating processes cannot simultaneously meet the processability and long service life requirements of multi-unit blades. Existing methods have inherent shortcomings in CMAS protection, coating uniformity, and adhesion, and lack dedicated processes for complex structures. Therefore, developing a novel plating method that can improve coating corrosion resistance, adapt to the geometry of multi-unit blades, and enhance interfacial bonding strength has become an urgent industry need. Summary of the Invention

[0007] This invention provides a method for coating a corrosion-resistant thermal barrier coating on multi-section guide vanes. Against the background described above, the invention aims to overcome the aforementioned technical bottlenecks through innovative pretreatment, adhesive layer, and ceramic layer design.

[0008] The technical solution of this invention is:

[0009] A method for applying a corrosion-resistant thermal barrier coating to multi-section guide vanes includes the following steps:

[0010] (1) Pretreatment process: The coating area of ​​the multi-section guide vane is sandblasted using zirconia ceramic pellets. The zirconia ceramic pellets have a particle size of 0.3~0.4mm, a ZrO2 content of 94.6~95.0wt%, and a Y2O3 content of 5.0~5.4wt%. The sandblasting parameters include: sandblasting distance of 150~200mm, compressed air pressure of 0.25~0.35 MPa, sandblasting angle of 20~30°, turntable speed of 30~40rpm, and sandblasting gun moving speed of 50%. Spraying is carried out within 2 hours after sandblasting.

[0011] (2) Metal bonding layer coating process: The blade is placed on a special coating fixture, and a NiCoCrAlYHfSi metal bonding layer is coated using a supersonic flame spraying process. The bonding layer composition is Ni-(18~26)Co-(13~21)Cr-(10~15)Al-(0.2~0.8)Y-(0.1~0.5)Hf-(0.1~0.7)Si, and its particle size range is -63~+22μm; the spraying parameter package... Includes: barrel length 101.6mm, spraying distance 320~380mm, powder feeding rate 75~85g / min, powder count 34~38%, stirring rate 49~51%, oxygen flow rate 830±20NLPM, kerosene flow rate 20±2L / h, carrier gas is argon, carrier gas flow rate 9±2NLPM, part rotation speed 600±60rpm, spray gun moving speed 100±10mm / s, and spraying angle (80~90)°;

[0012] (3) Ceramic layer coating process: During spraying, the blades are assembled into a ring according to the assembly state, and then a cover plate is used to protect and press the edge plate area. The YSZ layer and GdPO4 layer are coated sequentially using atmospheric plasma spraying:

[0013] The YSZ layer spraying parameters include: nozzle diameter of 9mm, spraying distance of 130mm±10mm, current of 500±10A, voltage of 122~142V, power of 59.8~72.4kW, main gas is argon with a flow rate of 70±2NLPM, secondary gas is hydrogen with a flow rate of 8±1NLPM, powder feeding gas argon flow rate of 3±0.5NLPM, powder feeding rate of 37±5g / min, powder feeding count of 28~30%, and stirring rate of 49~51%.

[0014] The GdPO4 layer spraying parameters include: nozzle diameter of 6mm, spraying distance of 100mm±10mm, current of 600±20A, voltage of 78±5V, power of 44±5kW, main gas is argon with a flow rate of 40±5NLPM, secondary gas is hydrogen with a flow rate of 14±2NLPM, powder feeding argon flow rate of 3±0.3NLPM, powder feeding rate of 37±5g / min, powder feeding count of 25~35%, and stirring rate of 45~55%.

[0015] Furthermore, in the aforementioned method for coating multi-unit guide vanes with a corrosion-resistant thermal barrier coating, the dedicated coating fixture includes a base, a positioning plug, an inner pressure cap, an outer pressure cap, and a clamping bolt. The positioning plug is installed under the base for axial positioning by engaging with the center hole of the equipment turntable. The base has an annular groove for positioning the blade edge plates. The inner and outer cylindrical surfaces of the annular groove are the positioning surfaces for the large and small end edge plates of the blade. All blades of the same stage can be clamped in one circumference, significantly improving processing efficiency. The inner and outer pressure caps are designed with drum-shaped grooves for easy and quick loading and unloading. In the working state, the small groove opening is smaller than the head of the clamping bolt, which can clamp the pressure cap and the blade. In the loading and unloading state, only a few turns of the clamping bolt need to be loosened (without completely unscrewing the clamping bolt), and the pressure cap can be rotated to the large groove opening for loading and unloading. The large groove opening is larger than the head of the clamping bolt, which allows the pressure cap to be loaded and unloaded. This provides good operability, improves work efficiency, and avoids obstructing the spraying area of ​​the blade body.

[0016] Furthermore, in the above-mentioned method for coating a corrosion-resistant thermal barrier coating on a multi-section guide vane, the zirconia ceramic pellets have a bulk density of 6.02~6.05 g / cm³, a hardness of not less than 1250 HV, and a uniform, non-metallic surface after sandblasting.

[0017] Furthermore, in the above-mentioned method for coating a corrosion-resistant thermal barrier coating on a multi-section guide vane, the powder incident angle of the YSZ layer is 90° and the spraying angle is 60°~90°; the powder incident angle of the GdPO4 layer is 75° and the spraying angle is 60°~90°.

[0018] Furthermore, in the above-mentioned method for coating a corrosion-resistant thermal barrier coating on a multi-section guide vane, the powder density of the GdPO4 layer is 0.78 g / cm³. 3 The particle size distribution is as follows: 95.12% of the powder is between -120 and +500 mesh, and 3.88% is between -500 mesh. The flowability is 118s / 50g.

[0019] Furthermore, in the above-mentioned method for coating a corrosion-resistant thermal barrier coating on a multi-section guide vane, the thickness of the NiCoCrAlYHfSi metal bonding layer is 0.05-0.10 mm, the thickness of the YSZ layer is 0.15-0.20 mm, and the thickness of the GdPO4 layer is 0.05-0.10 mm.

[0020] Furthermore, in the above-mentioned method for coating a corrosion-resistant thermal barrier coating on a multi-section guide vane, the coating thickness after coating is uniform, and after 100 hours of gas thermal corrosion at 900℃ and 60 cycles of water-cooled thermal shock at 1100℃, the coating shows no peeling or delamination.

[0021] Advantages and beneficial effects of the present invention:

[0022] 1. This invention uses zirconia ceramic shot blowing pretreatment to replace traditional white corundum, avoiding particle embedding in the matrix, producing a uniform and smooth surface profile, significantly enhancing the coating interface adhesion, and solving the problem of uneven coating in narrow areas of multi-unit blades.

[0023] 2. The NiCoCrAlYHfSi metal bonding layer and the YSZ / GdPO4 double-layer ceramic surface layer of this invention work synergistically to significantly improve resistance to CMAS corrosion and thermal shock. The coating showed no peeling or delamination after high-temperature testing, and its lifespan is expected to be increased by more than 50%.

[0024] 3. The special fixture design of this invention ensures comprehensive spray coverage, uniform coating thickness distribution, and no missed areas or weak points, making it suitable for blades with complex geometries.

[0025] 4. This invention integrates and optimizes parameters (such as spraying distance and powder feeding rate), improving batch clamping efficiency by 30% and meeting the requirements of high bonding strength (>30MPa), long life (over 2000 hours) and high reliability of thermal barrier coatings. Attached Figure Description

[0026] Figure 1 A cross-sectional view of a coating fixture for multi-unit blades;

[0027] Figure 2 for Figure 1 AA-side view;

[0028] Figure 3 A schematic diagram showing the working and loading / unloading states of a special coating fixture for multi-unit blades;

[0029] Figure 4 The image shows the microstructure of the NiCoCrAlYHfSi / YSZ / GdPO4 coating in Example 1.

[0030] Figure 5 Macroscopic images of conventional NiCrAlYSi / YSZ and novel NiCoCrAlYHfSi / YSZ / GdPO4 coatings after 103 and 235 thermal cycles respectively under CMAS and large temperature gradient coupling conditions were obtained by using a thermal barrier coating service environment simulation tester.

[0031] Figure 6 This is the macroscopic morphology of the coating surface after 100 h of gas thermal corrosion at 900℃;

[0032] Figure 7 The macroscopic morphology of the coating surface after 60 water-cooled thermal shock cycles at 1100℃;

[0033] Figure 8 The macroscopic morphology after tensile bonding strength of the coating;

[0034] Figure 9A schematic diagram showing the anatomical position of the tetrapod leaf along the leaf midline;

[0035] Figure 10 Typical metallographic structures were coated along the anatomical position of the midline of the four-piece blade;

[0036] Among them, 1-base; 2-positioning plug; 3-inner pressure cover; 4-outer pressure cover; 5-clamping bolt; 6-annular groove. Detailed Implementation

[0037] The accompanying drawings and embodiments described herein provide a further detailed description of specific implementations of the present invention. The following embodiments are for illustrative purposes only and should not be used to limit the scope of the present invention.

[0038] In a specific implementation, a dedicated coating fixture, such as... Figure 1-3 As shown, the system includes a base 1, a positioning plug 2, an inner pressure cover 3, an outer pressure cover 4, and a clamping bolt 5. The positioning plug 2 is installed under the base 1 for axial positioning in conjunction with the center hole of the equipment turntable. The base 1 has an annular groove 6 for positioning the blade edge plates. The inner and outer cylindrical surfaces of the annular groove are the positioning surfaces for the large and small end edge plates of the blades. All blades of the same stage can be clamped in one circumference, greatly improving processing efficiency. The inner pressure cover 3 and the outer pressure cover 4 are designed with a waist-shaped groove for easy and quick loading and unloading. In the working state, the small groove is smaller than the head of the clamping bolt, which can clamp the pressure cover and the blades. In the loading and unloading state, only a few turns of the clamping bolt need to be loosened (without completely unscrewing the clamping bolt), and the pressure cover can be rotated to the large groove for loading and unloading. The large groove is larger than the head of the clamping bolt, which allows the pressure cover to be loaded and unloaded. This improves operability, increases work efficiency, and avoids obstructing the blade spraying area.

[0039] Example 1

[0040] This embodiment describes a method for applying a corrosion-resistant thermal barrier coating to multi-unit guide vanes, comprising the following steps:

[0041] Zirconia ceramic pellets with a particle size of 0.3 mm, a ZrO2 content of 94.6 wt%, and a Y2O3 content of 5.4 wt% were used to perform sandblasting treatment on the coating area of ​​the multi-unit guide vanes. The zirconia ceramic pellets had a bulk density of 6.02 g / cm³, a hardness of 1280 HV, a sandblasting distance of 150 mm, a compressed air pressure of 0.25 MPa, a sandblasting angle of 20°, a turntable speed of 30 rpm, and a sandblasting gun movement speed of 50%. Spraying was performed within 1 hour after sandblasting.

[0042] Eight sets of blades were placed and fixed on a special coating fixture. A NiCoCrAlYHfSi metal bonding layer was deposited using a supersonic flame spraying process. The bonding layer composition was Ni-18Co-13Cr-10Al-0.2Y-0.1Hf-0.1Si, with a particle size range of -63 to +22 μm. The spray gun barrel length was 101.6 mm, the spraying distance was 320 mm, the powder feed rate was 75 g / min, the powder count was 34%, the stirring rate was 49%, the oxygen flow rate was 810 NLPM, the kerosene flow rate was 18 L / h, the carrier gas was argon with a flow rate of 7 NLPM, the part rotation speed was 540 rpm, the spray gun moving speed was 90 mm / s, and the spraying angle was 80°.

[0043] A YSZ / GdPO4 double-layer ceramic coating was prepared using plasma spraying. The YSZ coating was sprayed using a 9mm nozzle diameter, a 120mm spraying distance, a 490A current, a 122V voltage, a 59.8kW power output, argon as the primary gas (68 NLPM), hydrogen as the secondary gas (7 NLPM), argon as the powder feed gas (2.5 NLPM), a powder feed rate of 32 g / min, a powder count of 28%, a stirring rate of 49%, a powder incident angle of 90°, and a spraying angle of 60°. The plasma-sprayed GdPO4 coating had a powder density of 0.78 g / cm³. 3 The particle size distribution is as follows: 95.12% of the powder is between -120 and +500 mesh, and 3.88% is between -500 mesh. The flowability is 118s / 50g. The spraying parameters are: nozzle diameter 6mm, spraying distance 90mm, current 580A, voltage 73V, power 39kW, main gas is argon with a flow rate of 35NLPM, secondary gas is hydrogen with a flow rate of 12NLPM, argon powder feed gas flow rate is 2.7NLPM, powder feed rate is 32g / min, powder count is 25%, stirring rate is 45%, powder incident angle is 75°, and spraying angle is 60°.

[0044] The above-described spraying process was followed by metallographic analysis of the sample, and the metallographic microstructure of the coating was obtained as follows: Figure 4 As shown in the figure, it can be observed that there are no embedded particles at the NiCoCrAlYHfSi / matrix interface after zirconia ceramic shot blowing pretreatment, and the surface contour is uniform and smooth.

[0045] Multi-factor coupled tests were conducted on conventional NiCrAlYSi / YSZ and novel NiCoCrAlYHfSi / YSZ / GdPO4 coatings under CMAS and large temperature gradient coupled conditions. Specific test conditions were: coating sample surface temperature 1250℃, substrate temperature 1050℃, CMAS suspension sprayed onto the coating surface and held at that temperature for 5 min, followed by compressed air cooling to room temperature for 90 s, completing one cycle. The number of thermal cycles at which coating failure occurred was recorded as the coating thermal cycle life under these conditions. For comparison, conventional thermal barrier coating samples were tested for thermal cycle performance under the same conditions. When the surface peeling of the conventional thermal barrier coating exceeded 20%, it was considered to have failed, and the test was stopped. Figure 5 Macroscopic images show the conventional NiCrAlYSi / YSZ and the novel NiCoCrAlYHfSi / YSZ / GdPO4 coatings after 103 and 235 thermal cycles, respectively, under CMAS and large temperature gradient coupling conditions. The images reveal that after 103 thermal cycles, the conventional thermal barrier coating exhibits significant CMAS adhesion on its surface, and severe spalling (exfoliation area exceeding 20%) is clearly observed. This indicates that the conventional thermal barrier coating's CMAS-coupled thermal cycle life does not exceed 103 cycles. The conventional thermal barrier coating uses YSZ as its ceramic layer, and numerous studies have shown that YSZ has poor resistance to CMAS corrosion. Under CMAS, the YSZ coating undergoes structural damage and phase transformation, leading to premature spalling. In contrast, the thermal barrier coating in this embodiment showed no significant spalling after 235 thermal cycles, and its surface remained relatively clean, unlike the conventional thermal barrier coating samples which exhibited significant CMAS adhesion. This demonstrates that the developed NiCoCrAlYHfSi / YSZ / GdPO4 coating possesses excellent corrosion resistance.

[0046] The prepared NiCoCrAlYHfSi / YSZ / GdPO4 coating was subjected to a 900℃ gas thermal corrosion test for 100 h according to the HB7740-2004 gas thermal corrosion test method. The macroscopic morphology of the coating surface after the test is as follows. Figure 6 As shown, no obvious corrosion can be observed on the coating surface, indicating that the coating has good corrosion resistance. Figure 7 The image shows the macroscopic morphology of the coating surface after 60 water-cooled thermal shock cycles at 1100℃. The coating surface remains continuous and intact, indicating that the coating has good adhesion.

[0047] The bonding strength of the developed NiCoCrAlYHfSi / YSZ / GdPO4 coating was measured according to the test method for bonding strength of thermal spray coatings in HB 5476-1991. Figure 8 The images show the macroscopic morphology after tensile bonding strength of the coating. The bonding strengths are 56.90 MPa, 50.02 MPa, and 47.72 MPa, respectively, and the coating bonding strength is 51.54 MPa, indicating good interfacial bonding of the coating.

[0048] according to Figure 9 The sprayed quadrilateral blades were cut and metallographically sampled, and the coating thickness was measured at four different locations on the blade body. Figure 10 Typical metallographic structures of the coating were observed along the anatomical location of the four-piece blade along the blade's centerline. The figures show that the metallographic structures at different locations on the blade are similar. Table 1 shows the coating thickness distribution along the anatomical location of the four-piece blade along the blade's centerline; Table 1 also shows that the coating thickness distribution is uniform among different multi-piece blades.

[0049] Table 1. Results of coating thickness inspection on parts

[0050]

[0051] Example 2

[0052] This embodiment describes a method for applying a corrosion-resistant thermal barrier coating to multi-unit guide vanes, comprising the following steps:

[0053] Zirconia ceramic pellets with a particle size of 0.4 mm, a ZrO2 content of 95 wt.%, and a Y2O3 content of 5.0 wt% were used to perform sandblasting treatment on the coating area of ​​the multi-unit guide vanes. The zirconia ceramic pellets had a bulk density of 6.05 g / cm³, a hardness of 1310 HV, a sandblasting distance of 200 mm, a compressed air pressure of 0.35 MPa, a sandblasting angle of 30°, a turntable speed of 40 rpm, and a sandblasting gun movement speed of 50%. Spraying was performed within 2 hours after sandblasting.

[0054] A ring of 12 blades is fixed on a special coating fixture. A NiCoCrAlYHfSi metal bonding layer is deposited using a supersonic flame spraying process. The bonding layer composition is Ni-26Co-21Cr-15Al-0.8Y-0.5Hf-0.7Si, with a particle size range of -63 to +22 μm. The spray gun barrel length is 101.6 mm, the spraying distance is 380 mm, the powder feed rate is 85 g / min, the powder count is 38%, the stirring rate is 51%, the oxygen flow rate is 850 NLPM, the kerosene flow rate is 22 L / h, the carrier gas is argon with a flow rate of 11 NLPM, the part rotation speed is 660 rpm, the spray gun moving speed is 110 mm / s, and the spraying angle is 90°.

[0055] A YSZ / GdPO4 double-layer ceramic coating was prepared using plasma spraying. The YSZ coating was sprayed using a 9mm nozzle diameter, a 140mm spraying distance, a 510A current, a 142V voltage, a 72.4kW power output, with argon as the primary gas (72 NLPM) and hydrogen as the secondary gas (9 NLPM). The argon feed gas flow rate was 3.5 NLPM, the powder feed rate was 42 g / min, the powder count was 30%, the stirring rate was 51%, the powder incident angle was 90°, and the spraying angle was 90°. The plasma-sprayed GdPO4 coating had a powder density of 0.78 g / cm³. 3 The powder has a particle size distribution of -120 to +500 mesh (95.12%) and -500 mesh (3.88%), with a flowability of 118 s / 50g. The spraying parameters are: nozzle diameter 6mm, spraying distance 110mm, current 620A, voltage 83V, power 49kW, primary gas argon with a flow rate of 45 NLPM, secondary gas hydrogen with a flow rate of 16 NLPM, argon feed gas flow rate of 3.3 NLPM, feed rate 42g / min, feed count 35%, stirring rate 55%, powder incident angle 75°, and spraying angle 90°.

[0056] After spraying, the blades were inspected for consistency in appearance and thickness to ensure they met acceptance requirements.

Claims

1. A method for coating corrosion-resistant thermal barrier coatings onto multi-section guide vanes, characterized in that, Includes the following steps: (1) Pretreatment process: The coating area of ​​the multi-section guide vane is sandblasted using zirconia ceramic pellets. The zirconia ceramic pellets have a particle size of 0.3~0.4mm, a ZrO2 content of 94.6~95.0wt%, and a Y2O3 content of 5.0~5.4wt%. The sandblasting parameters include: sandblasting distance of 150~200mm, compressed air pressure of 0.25~0.35 MPa, sandblasting angle of 20~30°, turntable speed of 30~40rpm, and sandblasting gun moving speed of 50%. Spraying is carried out within 2 hours after sandblasting. (2) Metal bonding layer coating process: The blade is placed on a special coating fixture, and a NiCoCrAlYHfSi metal bonding layer is coated using a supersonic flame spraying process. The bonding layer composition is Ni-(18~26)Co-(13~21)Cr-(10~15)Al-(0.2~0.8)Y-(0.1~0.5)Hf-(0.1~0.7)Si, and its particle size range is -63~+22μm; the spraying parameter package... Includes: barrel length 101.6mm, spraying distance 320~380mm, powder feeding rate 75~85g / min, powder count 34~38%, stirring rate 49~51%, oxygen flow rate 830±20NLPM, kerosene flow rate 20±2L / h, carrier gas is argon, carrier gas flow rate 9±2NLPM, part rotation speed 600±60rpm, spray gun moving speed 100±10mm / s, and spraying angle (80~90)°; (3) Ceramic layer coating process: YSZ layer and GdPO4 layer are coated sequentially using atmospheric plasma spraying process: The YSZ layer spraying parameters include: nozzle diameter of 9mm, spraying distance of 130mm±10mm, current of 500±10A, voltage of 122~142V, power of 59.8~72.4kW, main gas is argon with a flow rate of 70±2NLPM, secondary gas is hydrogen with a flow rate of 8±1NLPM, powder feeding argon flow rate of 3±0.5NLPM, powder feeding rate of 37±5g / min, powder feeding count of 28~30%, and stirring rate of 49~51%. The GdPO4 layer spraying parameters include: nozzle diameter of 6mm, spraying distance of 100mm±10mm, current of 600±20A, voltage of 78±5V, power of 44±5kW, main gas is argon with a flow rate of 40±5NLPM, secondary gas is hydrogen with a flow rate of 14±2NLPM, powder feeding argon flow rate of 3±0.3NLPM, powder feeding rate of 37±5g / min, powder feeding count of 25~35%, and stirring rate of 45~55%. The powder incident angle of the YSZ layer is 90° and the spraying angle is 60°~90°; the powder incident angle of the GdPO4 layer is 75° and the spraying angle is 60°~90°. The special coating fixture includes a base (1), a positioning plug (2), an inner pressure cover (3), an outer pressure cover (4), and a clamping bolt (5). The positioning plug (2) is installed under the base (1) for axial positioning in conjunction with the center hole of the equipment turntable. The base (1) is provided with an annular groove (6) for positioning the blade edge plate. The inner pressure cover (3) and the outer pressure cover (4) are designed with waist-shaped grooves for easy loading and unloading.

2. The method for applying a corrosion-resistant thermal barrier coating to a multi-section guide vane according to claim 1, characterized in that, The zirconium oxide ceramic pellets have a bulk density of 6.02~6.05 g / cm³, a hardness of not less than 1250 HV, and a uniform, non-metallic surface after sandblasting.

3. The method for applying a corrosion-resistant thermal barrier coating to a multi-section guide vane according to claim 1, characterized in that, The powder density of the GdPO4 layer is 0.78 g / cm³. 3 The particle size distribution is as follows: 95.12% of the powder is between -120 and +500 mesh, and 3.88% is between -500 mesh. The flowability is 118s / 50g.

4. The method for applying a corrosion-resistant thermal barrier coating to a multi-section guide vane according to claim 1, characterized in that, The thickness of the NiCoCrAlYHfSi metal bonding layer is 0.05-0.10 mm, the thickness of the YSZ layer is 0.15-0.20 mm, and the thickness of the GdPO4 layer is 0.05-0.10 mm.

5. The method for applying a corrosion-resistant thermal barrier coating to a multi-section guide vane according to claim 1, characterized in that, The coating applied by the method has a uniform thickness, and after 100 hours of gas thermal corrosion at 900℃ and 60 cycles of water-cooled thermal shock at 1100℃, the coating shows no peeling or delamination.

Images