PS-PVD thermal barrier coating and preparation method thereof

Abstract

The invention provides a PS-PVD thermal barrier coating and a preparation method thereof, relates to the technical field of thermal barrier coating preparation, and is designed for solving the problem that an existing thermal barrier coating formed on the surface of a turbine blade is high in cost. According to the preparation method of the PS-PVD thermal barrier coating, the median particle size D50 of ceramic powder adopted for preparing the thermal barrier coating is 6-8 microns, and the crushing strength of the ceramic powder is larger than 100 MPa when the deformation quantity is 10%; ceramic powder is fed into the plasma spray gun anode in a double-side powder feeding mode, the powder feeding direction is opposite to the jet flow direction, and the included angle between the cross section of the powder feeding direction and the cross section of the jet flow direction is alpha; in the plasma main gas, the flow ratio of argon to helium is 1: 1-8: 1. According to the preparation method, the preparation cost of the PS-PVD thermal barrier coating can be remarkably reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal barrier coating preparation, and in particular to a PS-PVD thermal barrier coating and a preparation method thereof. Background Art

[0002] The core hot end components of aircraft engines and gas turbines are turbine blades, and thermal barrier coatings are an indispensable key thermal protection technology for the surface of turbine blades. Thermal barrier coatings are mainly composed of metal bonding layers and ceramic thermal insulation layers. The ceramic thermal insulation layer slows down heat transfer by reducing phonon scattering and reducing thermal radiation conduction, thereby playing a role in thermal insulation protection. During the operation of modern gas turbines, due to the continuous increase in the temperature of the turbine front end, the gas flow rate, temperature and the effects of external environmental deposits continue to intensify, which requires thermal barrier coatings to have higher thermal insulation performance while also having better resistance to environmental damage, such as resistance to high-temperature solid particle erosion.

[0003] However, existing methods for forming thermal barrier coatings on the surfaces of turbine blades are costly. Summary of the invention

[0004] The first object of the present invention is to provide a method for preparing a PS-PVD (Plasma Spray Physical Vapor Deposition) thermal barrier coating to solve the technical problem of high cost of existing methods for forming thermal barrier coatings on the surface of turbine blades.

[0005] The preparation method of the PS-PVD thermal barrier coating provided by the present invention, the median particle size D of the ceramic powder used to prepare the thermal barrier coating 50 The particle size of the ceramic powder is 6 to 8 μm, and the crushing strength of the ceramic powder is greater than 100 MPa when the deformation amount is 10%. The plasma spray gun anode adopts a double-sided powder feeding method to feed the ceramic powder, the powder feeding direction is opposite to the jet direction, and the angle between the cross section of the powder feeding direction and the jet direction is α. In the plasma main gas, the flow ratio of argon to helium is 1:1 to 8:1.

[0006] Furthermore, α is 20°±1°.

[0007] Furthermore, the powder delivery channels on both sides of the anode of the plasma spray gun are arranged symmetrically with the jet direction as the center line.

[0008] Furthermore, the powder feeding rate on each side of the plasma spray gun anode is 5 to 7 g / min.

[0009] Furthermore, the total flow rate of the plasma main gas is 90 slpm, wherein the flow rate of the argon gas is 45 to 80 slpm, and the flow rate of the helium gas is 10 to 45 slpm.

[0010] Furthermore, the powder carrier gas flow rate of the plasma main gas is 10 to 14 slpm.

[0011] Furthermore, the spraying current is 2000A, the spraying distance is 1000-1200mm, and the spraying power is 80-100kW.

[0012] Furthermore, the plasma spray gun and the sample are sprayed and deposited in a relative moving manner, the preheating temperature of the sample is 700-900° C., and the deposition rate of the thermal barrier coating is 3-6 μm / min.

[0013] The beneficial effects brought by the preparation method of the PS-PVD thermal barrier coating of the present invention are:

[0014] The median particle size D of the ceramic powder for preparing thermal barrier coating is 50 Setting it to 6-8μm, relative to the median particle size of 8-12μm of commercial powder, can reduce the fluidity of ceramic powder, thereby increasing the difficulty of powder transportation and spraying, so that the ceramic powder can be continuously transported and stably sprayed for a long time, and by setting the deformation of the ceramic powder at a pressure greater than 100MPa to 10%, the ceramic powder has a higher crushing strength, which significantly improves the uniformity of the powder during collapse, so that the deposition efficiency of the ceramic powder during the deposition process is increased to 30%, which is effectively improved compared to the 20% deposition efficiency of commercial powder, and lays a good foundation for low-cost coating preparation.

[0015] By feeding ceramic powder into the plasma spray gun anode by double-sided reverse powder feeding and controlling the powder feeding angle of the plasma spray gun anode, the compatibility of ceramic powder and high-speed plasma jet can be improved, and the adhesion of deposits inside the anode and its influence on jet stability can be reduced, thereby improving the interaction stability between ceramic powder and plasma jet. By limiting the flow ratio of argon to helium in the plasma main gas to between 1:1 and 8:1, the use of helium in the process is effectively reduced, thereby significantly reducing the process cost.

[0016] It can be seen that the preparation method of the PS-PVD thermal barrier coating can significantly reduce the preparation cost of the PS-PVD thermal barrier coating, thereby effectively solving the technical problem of high cost of the existing method for forming a thermal barrier coating on the surface of a turbine blade.

[0017] The second object of the present invention is to provide a PS-PVD thermal barrier coating to solve the technical problem of high cost of the existing thermal barrier coating formed on the surface of turbine blades.

[0018] The PS-PVD thermal barrier coating provided by the present invention is prepared by adopting the above-mentioned method for preparing the PS-PVD thermal barrier coating.

[0019] Furthermore, the microhardness of the PS-PVD thermal barrier coating is HV0.1>300.

[0020] The beneficial effects brought by the PS-PVD thermal barrier coating of the present invention are:

[0021] The PS-PVD thermal barrier coating obtained by the above preparation method has low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0023] Figure 1 A partial structural cross-sectional view of a plasma spray gun anode used in a method for preparing a PS-PVD thermal barrier coating provided in an embodiment of the present invention;

[0024] Figure 2 The cross-sectional morphology of the thermal barrier coating prepared by the preparation method of the PS-PVD thermal barrier coating provided in the embodiment of the present invention under the conditions of an argon flow rate of 60slpm, a helium flow rate of 30slpm, and a spraying current of 2000A;

[0025] Figure 3 The cross-sectional morphology of the thermal barrier coating prepared by the preparation method of the PS-PVD thermal barrier coating provided in an embodiment of the present invention under the conditions of an argon flow rate of 45slpm, a helium flow rate of 45slpm, and a spraying current of 2000A;

[0026] Figure 4 The cross-sectional morphology of the thermal barrier coating prepared by the preparation method of the PS-PVD thermal barrier coating provided in the embodiment of the present invention under the conditions of an argon flow rate of 50slpm, a helium flow rate of 40slpm, and a spraying current of 2000A;

[0027] Figure 5 The cross-sectional morphology of the thermal barrier coating prepared by the preparation method of the PS-PVD thermal barrier coating provided in the embodiment of the present invention under the conditions of an argon flow rate of 70slpm, a helium flow rate of 20slpm, and a spraying current of 2000A;

[0028] Figure 6 This is a comparison chart of deposition process costs of 200μm thick thermal barrier coating under different process conditions;

[0029] Figure 7 The figure shows the coating deposition efficiency and microhardness under several typical plasma main gas conditions.

[0030] Description of reference numerals:

[0031] 100-jet channel; 200-powder feeding channel. DETAILED DESCRIPTION

[0032] At present, the main preparation technologies of ceramic thermal insulation layers include APS (Air Plasma Spray), EB-PVD (Electron Beam Physical Vapor Deposition) and PS-PVD. Among them, APS thermal barrier coating is a typical layered structure coating. Due to the presence of multiple interfaces, multiple defects and high porosity, the thermal barrier coating has a good thermal insulation effect; EB-PVD thermal barrier coating is a typical columnar structure coating with high strain tolerance and long life characteristics; PS-PVD thermal barrier coating is a highly efficient gas-solid-liquid three-phase composite controlled deposition technology. When the gas phase is mainly deposited, a quasi-columnar structure coating can be obtained, and due to the gas phase nucleation preferential competitive growth mode, and the presence of a small amount of liquid phase and condensed nanoclusters, the coating forms a dendrite-developed structure, so that the thermal barrier coating formed by this technology has a high porosity and low thermal conductivity, as well as high strain tolerance and long life characteristics. However, the presence of high porosity and dendrite-developed structure leads to poor high temperature erosion resistance of the coating.

[0033] In view of this, relevant researchers have proposed to improve the high-temperature erosion resistance of thermal barrier coatings by means of surface densification and surface superposition of dense layers. However, the superposition process is complex, the process is long and the cost is high. Moreover, since PS-PVD uses the principle of differential pressure expansion to make the jet expand and elongate instantly and obtain high-energy, high-speed jets deposited over a large area, in order to constrain the atmosphere in the expansion flow, the low viscosity characteristics of helium are also used to make the gas phase more concentrated to obtain a quasi-columnar structure coating. Among them, the PS-PVD classic process current I is 2600A, the main gas is argon Ar and helium He, the total gas flow is 90-100slpm, and the Ar / He ratio is about 2. Since the cost of helium is more than 10 times that of hydrogen, the use of a large amount of helium has greatly increased the application cost of PS-PVD technology.

[0034] Therefore, the object of the present invention is to provide a PS-PVD thermal barrier coating and a preparation method thereof to solve the above technical problems.

[0035] In order to make the above-mentioned objects, features and advantages of the present invention more clearly understood, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0036] This embodiment provides a method for preparing a PS-PVD thermal barrier coating, wherein the median particle size D of the ceramic powder used to prepare the thermal barrier coating is 50 The particle size of the ceramic powder is 6 to 8 μm, and the crushing strength of the ceramic powder is greater than 100 MPa when the deformation amount is 10%. The plasma spray gun anode adopts a double-sided powder feeding method to feed the ceramic powder, the powder feeding direction is opposite to the jet direction, and the angle between the cross section of the powder feeding direction and the jet direction is α. In the plasma main gas, the flow ratio of argon to helium is 1:1 to 8:1.

[0037] The median particle size D of the ceramic powder for preparing thermal barrier coating is 50 Setting it to 6-8μm, relative to the median particle size of 8-12μm of commercial powder, can reduce the fluidity of ceramic powder, thereby increasing the difficulty of powder transportation and spraying, so that the ceramic powder can be continuously transported and stably sprayed for a long time, and by setting the deformation of the ceramic powder at a pressure greater than 100MPa to 10%, the ceramic powder has a higher crushing strength, which significantly improves the uniformity of the powder during collapse, so that the deposition efficiency of the ceramic powder during the deposition process is increased to 30%, which is effectively improved compared to the 20% deposition efficiency of commercial powder, and lays a good foundation for low-cost coating preparation.

[0038] By feeding ceramic powder into the plasma spray gun anode by double-sided reverse powder feeding and controlling the powder feeding angle of the plasma spray gun anode, the compatibility of ceramic powder and high-speed plasma jet can be improved, and the adhesion of deposits inside the anode and its influence on jet stability can be reduced, thereby improving the interaction stability between ceramic powder and plasma jet. By limiting the flow ratio of argon to helium in the plasma main gas to between 1:1 and 8:1, the use of helium in the process is effectively reduced, thereby significantly reducing the process cost.

[0039] It can be seen that the preparation method of the PS-PVD thermal barrier coating can significantly reduce the preparation cost of the PS-PVD thermal barrier coating, thereby effectively solving the technical problem of high cost of the existing method for forming a thermal barrier coating on the surface of a turbine blade.

[0040] like Figure 1 As shown, the angle α between the powder feeding direction and the jet direction is 20°±1°.

[0041] By limiting the angle α between the powder feeding direction and the jet direction within the above range, on the one hand, it can avoid the situation where the ceramic powder is directly sent to the high temperature zone due to α being too large, resulting in excessive evaporation and blocking the nozzle. On the other hand, it can also avoid the situation where the ceramic powder is directly sent to the low temperature zone due to α being too small, resulting in poor deposition effect.

[0042] Please continue to refer to Figure 1In this embodiment, the powder delivery channels 200 on both sides of the plasma spray gun anode are arranged symmetrically with the jet direction as the center line. In other words, the two powder delivery channels 200 are mirror-symmetrical with the jet channel 100. This arrangement can ensure uniform deposition.

[0043] In this embodiment, the powder feeding rate of each side of the plasma spray gun anode is 5-7 g / min. This setting can not only avoid the situation where the deposition effect is poor due to too fast a powder feeding rate, but also avoid the reduction of efficiency due to too slow a powder feeding rate.

[0044] In this embodiment, the powder carrier gas flow rate of the plasma main gas is 10-14 slpm.

[0045] In this embodiment, the spraying current is 2000A, the spraying distance is 1000-1200mm, and the spraying power is 80-100kW.

[0046] In this embodiment, the plasma spray gun and the sample are sprayed and deposited in a relative moving manner, the preheating temperature of the sample is 700-900° C., and the deposition rate of the thermal barrier coating is 3-6 μm / min.

[0047] In this embodiment, the total flow rate of the plasma main gas is 90 slpm, wherein the flow rate of the argon gas is 45 to 80 slpm, and the flow rate of the helium gas is 10 to 45 slpm.

[0048] The technical solution of the present invention will be described in detail below through specific embodiments.

[0049] Embodiment 1

[0050] The optimized ceramic powder used in this embodiment has a median particle size D of 1.37 mm / s as measured by a laser particle size analyzer. 50 The diameter of the ceramic powder is 6.89 μm, and the crushing strength of the ceramic powder is tested by a micro compression tester, wherein no less than 10 ceramic powder particles are tested separately. Under the condition of a deformation amount of 10%, the crushing strength of the ceramic powder is measured to be 153±15.5 MPa. After preparing the bonding layer, an anode with a powder feeding angle α of 20° is installed, and the current (I) is set to 2000A, the Ar flow rate is 60 slpm, the He flow rate is 30 slpm, the total plasma main gas flow rate is 90 slpm, and the Ar / He ratio is 2:1; the powder feeding carrier gas flow rate is 14 slpm, the powder feeding rate is 6 g / min, and the spraying distance is 1200 mm. The relative movement speed of the plasma spray gun and the sample is set. After spraying and depositing the thermal barrier coating, the microhardness HV of the thermal barrier coating is 0.1 is 336.1±67.2. The cross-sectional morphology of the thermal barrier coating under this process condition is as follows Figure 2As shown, it is a typical quasi-columnar structure. When the same ceramic powder is used under the conditions of spraying current 2000A, Ar 30slpm and He 60slpm, the microhardness is 146.3±21.5.

[0051] Embodiment 2

[0052] The optimized ceramic powder used in the second embodiment has a median particle size D of 1.1777 W / m2 measured by a laser particle size analyzer. 50 The diameter of the ceramic powder is 6.05 μm, and the crushing strength of the ceramic powder is tested by a micro compression tester, wherein no less than 10 ceramic powder particles are tested separately. Under the condition of a deformation amount of 10%, the crushing strength of the ceramic powder is measured to be 160±11 MPa. After preparing the bonding layer, an anode with a powder feeding angle α of 19° is installed, and the current (I) is set to 2000A, the Ar flow rate is 45 slpm, the He flow rate is 45 slpm, the total plasma main gas flow rate is 90 slpm, and the Ar / He ratio is 1:1; the powder feeding carrier gas flow rate is 12 slpm, the powder feeding rate is 5 g / min, and the spraying distance is 1100 mm. The relative movement speed of the plasma spray gun and the sample is set. After spraying and depositing the thermal barrier coating, the microhardness HV of the thermal barrier coating is 0.1 is 244.6±42.9. The cross-sectional morphology of the thermal barrier coating under this process condition is as follows Figure 3 As shown, it is a typical quasi-columnar structure. When the same ceramic powder is used under the conditions of spraying current 2000A, Ar 30slpm and He 60slpm, the microhardness is 168.4±24.1.

[0053] Embodiment 3

[0054] The optimized ceramic powder used in the third embodiment has a median particle size D of 1.1777 W / m2 measured by a laser particle size analyzer. 50 The diameter of the ceramic powder is 8.0μm, and the crushing strength of the ceramic powder is tested by a micro compression tester, wherein no less than 10 ceramic powder particles are tested separately. Under the condition of a deformation amount of 10%, the crushing strength of the ceramic powder is measured to be 150±11MPa. After preparing the bonding layer, an anode with a powder feeding angle α of 21° is installed, and the current (I) is set to 2000A, the Ar flow rate is 50slpm, the He flow rate is 40slpm, the total plasma main gas flow rate is 90slpm, and the Ar / He ratio is 5:4; the powder feeding carrier gas flow rate is 10slpm, the powder feeding rate is 7g / min, and the spraying distance is 1000mm. The relative movement speed of the plasma spray gun and the sample is set. After spraying and depositing the thermal barrier coating, the microhardness HV of the thermal barrier coating is 0.1 is 278.9±43.7. The cross-sectional morphology of the thermal barrier coating under this process condition is as follows Figure 4As shown, it is a typical quasi-columnar structure. When the same ceramic powder is used under the conditions of spraying current 2000A, Ar 30slpm and He 60slpm, the microhardness is 158.4±20.1.

[0055] Embodiment 4

[0056] The optimized ceramic powder used in Example 4 has a median particle size D of 1.3777 W / m2 measured by a laser particle size analyzer. 50 The diameter of the ceramic powder is 6.89 μm, and the crushing strength of the ceramic powder is tested by a micro compression tester, in which no less than 10 ceramic powder particles are tested separately. Under the condition of 10% deformation, the crushing strength of the ceramic powder is measured to be 153±15.5 MPa. After preparing the bonding layer, an anode with a powder feeding angle α of 20.3° is installed, and the current (I) is set to 2000A, the Ar flow rate is 70 slpm, the He flow rate is 20 slpm, the total plasma main gas flow rate is 90 slpm, and the Ar / He ratio is 7:2; the powder carrier gas flow rate is 12 slpm, the powder feeding rate is 5 g / min, and the spraying distance is 1000 mm. The relative movement speed of the plasma spray gun and the sample is set. After spraying and depositing the thermal barrier coating, the microhardness HV of the thermal barrier coating is 0.1 is 347.9±81.9. The cross-sectional morphology of the thermal barrier coating under this process condition is as follows Figure 5 As shown, it is a typical quasi-columnar structure. When the same ceramic powder is used under the conditions of spraying current 2000A, Ar 30slpm and He 60slpm, the microhardness is 146.3±21.5.

[0057] Embodiment 5

[0058] The optimized ceramic powder used in Example 5 has a median particle size D of 1.3777 W / m2 measured by a laser particle size analyzer. 50 The diameter of the ceramic powder is 6.89 μm, and the crushing strength of the ceramic powder is tested by a micro compression tester, in which no less than 10 ceramic powder particles are tested separately. Under the condition of 10% deformation, the crushing strength of the ceramic powder is measured to be 153±15.5 MPa. After preparing the bonding layer, an anode with a powder feeding angle α of 19.7° is installed, and the current (I) is set to 2000A, the Ar flow rate is 80 slpm, the He flow rate is 10 slpm, the total plasma main gas flow rate is 90 slpm, and the Ar / He ratio is 8:1; the powder carrier gas flow rate is 12 slpm, the powder feeding rate is 5 g / min, and the spraying distance is 1100 mm. The relative movement speed of the plasma spray gun and the sample is set. After spraying and depositing the thermal barrier coating, the microhardness HV of the thermal barrier coating is 0.1The microhardness of the thermal barrier coating under this process condition is 404.7±69.2, and the cross section of the thermal barrier coating under this process condition is also a typical quasi-columnar structure. When the same ceramic powder is used under the conditions of spraying current 2000A, Ar30slpm and He60slpm, the microhardness is 146.3±21.5.

[0059] like Figure 6 As shown, by calculating the comprehensive cost ratio based on cost and deposition efficiency, where cost refers to process cost (auxiliary equipment power (60kW), actual power input of the spray gun, gas cost per hour), process cost is calculated as yuan / h, and deposition efficiency refers to the deposition rate of the plasma spray gun and the sample under the same relative motion relationship, marked in μm / min, and the deposition process cost of the thermal barrier coating with a thickness of 200μm under different process conditions is compared. Assuming that the relative cost of commercial powder is 1 under the conditions of spraying current 2000A, Ar30slpm and He60slpm, then the relative cost of the ceramic powder in Examples 1 to 5 is 0.66, and under the conditions of He of 30slpm and 10slpm, the above relative cost can be further reduced to 0.59 and 0.52.

[0060] like Figure 7 As shown, the relationship between deposition rate and microhardness under the process conditions of Ar30slpm and He60slpm, Ar60slpm and He30slpm, Ar65slpm and He25slpm, Ar70slpm and He20slpm, Ar75slpm and He15slpm, and Ar80slpm and He10slpm is shown. Among them, with the gradual increase of Ar in the plasma main gas, the deposition efficiency tends to decrease, while the microhardness tends to increase.

[0061] In the preparation method of the PS-PVD thermal barrier coating, compared with the classic standard process spraying current (I) 2600A, spraying power 120-130kW, Ar 30-35slpm, He 60slpm, the optimized ceramic powder and corresponding equipment of this embodiment are used to achieve the preparation of a quasi-columnar structure coating under a low-power (80-100kW) plasma spray gun input at a spraying current of 2000A, the power is reduced by 20-40kW, and at the same time, He is reduced by 1 / 3-5 / 6, which significantly reduces the process cost.

[0062] In summary, the preparation method of the PS-PVD thermal barrier coating overcomes the typical standard process defects of high power and high helium flow, reduces the use of rare and precious helium by 1 / 3 to 5 / 6, reduces the input power consumption of the plasma spray gun by 20 to 40 kW per hour, and increases the microhardness by more than 40%.

[0063] In addition, this embodiment also provides a PS-PVD thermal barrier coating, which is prepared using the above-mentioned preparation method of the PS-PVD thermal barrier coating.

[0064] The PS-PVD thermal barrier coating obtained by the above preparation method has low cost.

[0065] In addition, the PS-PVD thermal barrier coating obtained by the above preparation method has a microhardness of HV 0.1 >300, with high hardness, which effectively improves the thermal barrier coating's ability to resist environmental damage and prolongs its service life.

[0066] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

[0067] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the term "comprises" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprises a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0068] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a PS-PVD thermal barrier coating, characterized in that: The median particle size D of the ceramic powder used to prepare the thermal barrier coating 50 The particle size of the ceramic powder is 6 to 8 μm, and the crushing strength of the ceramic powder is greater than 100 MPa when the deformation amount is 10%. The plasma spray gun anode adopts a double-sided powder feeding method to feed the ceramic powder, the powder feeding direction is opposite to the jet direction, and the angle between the cross section of the powder feeding direction and the jet direction is α. In the plasma main gas, the flow ratio of argon to helium is 1:1 to 8:

1.

2. The method for preparing a PS-PVD thermal barrier coating according to claim 1, characterized in that: α is 20°±1°.

3. The method for preparing a PS-PVD thermal barrier coating according to claim 1, characterized in that: The powder delivery channels on both sides of the anode of the plasma spray gun are arranged symmetrically with the jet direction as the center line.

4. The method for preparing a PS-PVD thermal barrier coating according to claim 1, characterized in that: The powder feeding rate of each side of the plasma spray gun anode is 5-7 g / min.

5. The method for preparing a PS-PVD thermal barrier coating according to claim 1, characterized in that: The total flow rate of the plasma main gas is 90 slpm, wherein the flow rate of the argon gas is 45 to 80 slpm, and the flow rate of the helium gas is 10 to 45 slpm.

6. The method for preparing a PS-PVD thermal barrier coating according to claim 1, characterized in that: The powder carrier gas flow rate of the plasma main gas is 10 to 14 slpm.

7. The method for preparing a PS-PVD thermal barrier coating according to claim 1, characterized in that: The spraying current is 2000A, the spraying distance is 1000-1200mm, and the spraying power is 80-100kW.

8. The method for preparing a PS-PVD thermal barrier coating according to claim 1, characterized in that: The plasma spray gun and the sample are sprayed and deposited in a relative moving manner, the preheating temperature of the sample is 700-900° C., and the deposition rate of the thermal barrier coating is 3-6 μm / min.

9. A PS-PVD thermal barrier coating, characterized in that: The PS-PVD thermal barrier coating is prepared by the preparation method according to any one of claims 1 to 8.

10. The PS-PVD thermal barrier coating according to claim 9, characterized in that: The microhardness of the PS-PVD thermal barrier coating is HV 0.1 >300.

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