Multi-layer gradient coating with high-temperature oxidation resistance, abradability and self-lubricating functions and preparation method of multi-layer gradient coating

Abstract

The invention relates to a multi-layer gradient coating with high-temperature oxidation resistance, abradability and self-lubricating functions and a preparation method of the multi-layer gradient coating. The multi-layer gradient coating sequentially comprises a bonding layer, a component transition layer, a high-temperature oxidation resistance layer, a self-lubricating transition layer and an abradability surface layer from a base body to the surface. The coating integrates high-temperature oxidation resistance, abradability and self-lubricating functions, breaks through performance contradiction of different coating materials through collaborative optimization of a material system, improves interlayer bonding force, and avoids falling failure.

Description

Technical Field

[0001] The invention relates to the field of thermal spraying technology, and in particular to a multilayer gradient coating with high temperature oxidation resistance, wear resistance and self-lubrication functions and a preparation method thereof. Background Art

[0002] At present, the high-temperature sealing coating technology has the following bottlenecks: the contradiction between high-temperature oxidation resistance and abradability. Traditional abradable coatings (such as porous NiCrAlY) have high porosity (>20%) and fast oxidation rate at high temperature (weight gain >10 mg / cm² at 1000℃ / 100h), which leads to sealing failure. Insufficient self-lubricating performance, graphite or MoS 2 The base lubricating coating has poor temperature resistance (decomposition at <500°C), while high temperature solid lubricants (such as CaF 2 ) has low bonding strength with the metal matrix (<30 MPa). The interlayer thermal mismatch is serious. Multilayer coatings are prone to interface cracks (stress > 300 MPa) due to differences in thermal expansion coefficients (such as ceramics and metals), and are prone to peeling under dynamic conditions.

[0003] CN104278226A discloses a preparation technology of a wide temperature range self-lubricating coating. The coating is prepared by atmospheric plasma spraying technology. The spraying powder is composed of NiCrAlY, Cr 2 O 3 , Ag and CaF 2 / BaF 2 The eutectic is composed of four powders. 2 O 3 -Ag-CaF 2 / BaF 2 The wide temperature range self-lubricating coating has a low friction coefficient and wear rate in the temperature range of 20°C to 1000°C. CN115287592A discloses a high temperature wear-resistant self-lubricating coating for fingertip sealing and a preparation method thereof, wherein the high temperature wear-resistant self-lubricating coating comprises: a metal Me bonding layer, a composition gradient transition layer and a high temperature wear-resistant self-lubricating surface layer sequentially stacked in the thickness direction; the composition gradient transition layer is Me-MeN-MeN / MoS 2 Transition layer; the high temperature wear-resistant self-lubricating surface layer is MeN / MoS 2 The composite layer reduces the internal stress by setting the gradient content. However, the existing technology still focuses on improving a single function and fails to overcome the performance contradiction of a single material.

[0004] Therefore, it is urgent to develop a gradient coating that integrates the functions of "anti-oxidation-wear resistance-self-lubricating" to break through the performance contradiction through coordinated optimization of material system and process. Summary of the invention

[0005] In order to solve the above technical problems, the present invention successfully combines high-temperature oxidation resistance, wear resistance and self-lubrication functions by setting a multi-layer gradient coating, while maintaining good interlayer bonding to avoid spalling failure under dynamic conditions caused by differences in thermal expansion coefficients.

[0006] To achieve this object, the present invention adopts the following technical solutions: In the first aspect, the present invention provides a multilayer gradient coating with high-temperature oxidation resistance, wear resistance and self-lubricating functions, wherein the multilayer gradient coating includes a bonding layer, a component transition layer, a high-temperature oxidation resistance layer, a self-lubricating transition layer and a wearable surface layer in sequence from the substrate to the surface.

[0007] The present invention realizes multifunctional integration by setting up a multi-layer gradient coating. The bonding layer and the component transition layer can improve the bonding strength between the coating and the substrate; the high-temperature oxidation resistant layer improves the high-temperature oxidation resistance of the coating; the self-lubricating transition layer can release the lubricating phase at high temperature to reduce the friction coefficient; the abrasive surface layer can reduce the overall hardness and brittleness of the coating, thereby realizing controllable wear.

[0008] As a preferred technical solution of the present invention, the bonding layer is a first alloy powder; the composition transition layer includes a first alloy powder and a second alloy powder; the high temperature oxidation resistant layer includes a second alloy powder and Al 2 O 3 Nanoparticles; the self-lubricating transition layer comprises a first alloy powder and a first lubricating phase powder; the abradable surface layer comprises a porous first alloy powder and a second lubricating phase powder.

[0009] The invention introduces aluminum oxide nanoparticles into the high temperature oxidation resistant layer, and can form a dense aluminum oxide film on the surface, thereby improving the high temperature oxidation resistance of the coating.

[0010] As a preferred technical solution of the present invention, the volume content of the second alloy powder in the composition transition layer increases from 0% to 100% from the bonding layer to the high temperature oxidation resistant layer.

[0011] Preferably, the thickness of the composition transition layer is 50-80 μm, for example, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm or 80 μm.

[0012] Preferably, the first alloy powder in the bonding layer comprises NiCrAlY powder.

[0013] Preferably, the particle size of the first alloy powder is 15-45 μm, for example, 15 μm, 18 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm or 45 μm.

[0014] Preferably, the NiCrAlY powder includes Ni-22Cr-10Al-1Y powder.

[0015] Preferably, the thickness of the bonding layer is 50-80 μm, for example, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm or 80 μm.

[0016] As a preferred technical solution of the present invention, the Al in the high temperature oxidation resistant layer 2 O 3 The mass fraction of the nanoparticles is 3-10%, for example, 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10%.

[0017] The present invention optimizes the Al content in the high temperature oxidation resistant layer. 2 O 3 When the mass fraction of the nanoparticles is within the above range, a dense aluminum oxide film can be formed while ensuring good interlayer interface bonding strength.

[0018] Preferably, the Al 2 O 3 The particle size of the nanoparticles is 10-60 nm, for example, it can be 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm or 60 nm.

[0019] Preferably, the second alloy powder comprises CoNiCrAlY powder.

[0020] Preferably, the particle size of the second alloy powder is 15-45 μm, for example, 15 μm, 18 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm or 45 μm.

[0021] Preferably, the CoNiCrAlY powder includes Co-32Ni-21Cr-8Al-0.5Y.

[0022] The present invention introduces Co metal into the second alloy powder. The addition of Co reduces the diffusion activation energy of Al, accelerates the diffusion of Al element to the coating surface, and preferentially promotes the formation of continuous and dense α-Al 2 O 3 The oxide film layer is formed, which reduces the generation of porous mixed oxides by Ni, thereby further improving the density of the high-temperature oxidation layer, improving the antioxidant capacity, and significantly improving the overall performance of the coating.

[0023] Preferably, the coating thickness of the high temperature oxidation resistant layer is 100-150 μm, for example, it may be 100 μm, 110 μm, 120 μm, 130 μm, 140 μm or 150 μm.

[0024] As a preferred technical solution of the present invention, the mass fraction of the first lubricating phase powder in the self-lubricating transition layer is 20-40%, for example, it can be 20%, 22%, 24%, 26%, 28%, 30%, 32%, 38% or 40%.

[0025] Preferably, the first lubricating phase powder in the self-lubricating transition layer comprises Ag powder and CaF 2 powder.

[0026] Preferably, the Ag powder and CaF 2 The particle size of the powder is 10-38 μm, for example, it can be 10 μm, 12 μm, 14 μm, 16 μm, 20 μm, 22 μm, 26 μm, 30 μm, 34 μm or 38 μm, etc.

[0027] Preferably, the particle size of the first alloy powder in the self-lubricating transition layer is 15-45 μm, for example, 15 μm, 18 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm or 45 μm.

[0028] As a preferred technical solution of the present invention, the Ag powder and CaF 2 The mass ratio of the powder is 2:1-4:1, for example, it can be 2:1, 2.2:1, 2.4:1, 2.6:1, 3:1, 3.2:1, 3.4:1, 3.6:1, 3.8:1 or 4:1, etc.

[0029] Preferably, the Ag powder is enriched in the surface layer of the self-lubricating transition layer, and the CaF2 powder is enriched in the inner layer of the self-lubricating transition layer.

[0030] Preferably, the coating thickness of the self-lubricating transition layer is 50-80 μm, for example, it can be 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm or 80 μm.

[0031] The present invention uses Ag and CaF in the self-lubricating transition layer. 2 As the first lubricating phase, the ductility of Ag enables it to form a continuous lubricating film through plastic deformation at low temperatures. 2 Strengthen high-temperature lubrication and effectively inhibit high-temperature adhesive wear. Gradient transition has no lubrication blind area, achieving a reduction in friction coefficient over the entire temperature range. Ag enriched in the surface layer can prevent oxygen from diffusing to the bottom layer, while CaF 2 The bottom layer inhibits the upward migration of elements such as Co and Cr, avoiding the formation of brittle phases.

[0032] As a preferred technical solution of the present invention, the mass fraction of the second lubricating phase powder in the abradable surface layer is 3%-5%, for example, it can be 3%, 3.2%, 3.8%, 4%, 4.2%, 4.8% or 5%.

[0033] Preferably, the second lubricating phase powder comprises h-BN powder.

[0034] Preferably, the thickness of the abradable surface layer is 80-120 μm, for example, 80 μm, 90 μm, 100 μm, 110 μm or 120 μm.

[0035] As a preferred technical solution of the present invention, the average porosity of the porous first alloy powder is 20-40%, for example, it can be 20%, 25%, 30%, 35% or 40%, etc.; the porosity of the abradable surface layer is 15-30%, for example, it can be 15%, 18%, 21%, 24%, 27% or 30%, etc.

[0036] Preferably, the particle size of the porous first alloy powder is 25-53 μm, for example, 25 μm, 27 μm, 30 μm, 34 μm, 38 μm, 40 μm, 44 μm, 48 μm, 50 μm or 53 μm.

[0037] In a second aspect, the present invention provides a method for preparing a multilayer gradient coating as described in the first aspect, the preparation method comprising: sequentially spraying a bonding layer, a component transition layer and a high-temperature oxidation resistant layer on a pretreated substrate using a supersonic plasma method, spraying a self-lubricating transition layer using a magnetic field-assisted supersonic plasma, and spraying an abradable surface layer using atmospheric plasma.

[0038] The present invention prepares a bonding layer, a component transition layer and a high temperature oxidation resistant layer with low porosity by supersonic plasma spraying. While fully melting the first alloy powder by plasma spraying, a portion of aluminum oxide is formed in the coating by plasma high temperature oxidation. A high porosity abradable surface layer is prepared by atmospheric plasma spraying.

[0039] Preferably, the pretreatment comprises sandblasting the surface of the substrate.

[0040] Preferably, the sand material for sandblasting includes 120 mesh white corundum.

[0041] Preferably, sand blasting is performed after the sand blasting, and the roughness of the surface of the substrate after the sand blasting is 4-6 μm, for example, 4 μm, 4.4 μm, 4.8 μm, 5 μm, 5.4 μm, 5.8 μm or 6 μm.

[0042] Preferably, the sand blasting is followed by ultrasonic cleaning with a mixed solution of acetone and ethanol.

[0043] Preferably, the spraying power of the supersonic plasma spraying is 40-45KW, for example, it can be 40KW, 41KW, 42KW, 43KW, 44KW or 45KW.

[0044] Preferably, the working gas for supersonic plasma spraying is propane and oxygen, the flow rate of the propane is 250-350 SLPM, for example, it can be 250 SLPM, 280 SLPM, 300 SLPM, 320 SLPM or 350 SLPM, and the flow rate of the oxygen is 750-850 SLPM, for example, it can be 750 SLPM, 780 SLPM, 800 SLPM, 820 SLPM or 850SLPM, etc.

[0045] Preferably, the powder feeding rate of the supersonic plasma spraying is 30-40 g / min, for example, it can be 30 g / min, 32 g / min, 34 g / min, 36 g / min, 38 g / min or 40 g / min.

[0046] Preferably, the spraying distance of the supersonic plasma spraying is 120-150 mm, for example, it can be 120 mm, 125 mm, 130 mm, 135 mm, 140 mm or 150 mm.

[0047] The preferred spraying distance of the present invention is within the above range to avoid overheating of the substrate due to a too short spraying distance, incomplete solidification of the particles, excessive porosity, and excessive oxidation of the coating due to a too long spraying distance.

[0048] Preferably, the cooling gas for supersonic plasma spraying is nitrogen, and the flow rate of the nitrogen is 10-20 SLPM, for example, 10 SLPM, 11 SLPM, 12 SLPM, 15 SLPM or 20 SLPM.

[0049] Preferably, the moving speed of the spray gun of the supersonic plasma spraying is 500-1000 mm / s, for example, it can be 500 mm / s, 600 mm / s, 700 mm / s, 800 mm / s, 900 mm / s or 1000 mm / s.

[0050] Preferably, the overlap rate of the supersonic plasma spraying is 40-50%, for example, it can be 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48% or 50%.

[0051] The present invention preferably sets the spray gun movement speed and overlap rate within the above range to ensure uniformity of coating spraying and keep the thickness fluctuation within 5 μm.

[0052] Preferably, the spraying of the component transition layer adopts double-drum powder feeding.

[0053] The present invention adjusts the powder feeding ratio by double-drum powder feeding to achieve gradient composition adjustment of the composition transition layer and realize the thermal expansion coefficient from 14.5×10-6 / K gradient transition to 13.8×10 -6 / K, improve the interlayer bonding strength of the coating.

[0054] Preferably, the magnetic field strength of the magnetic field-assisted supersonic plasma spraying is 0.4-0.5T, for example, it can be 0.4T, 0.42T, 0.44T, 0.46T, 0.48T or 0.5T.

[0055] Preferably, the direction of the magnetic field is perpendicular to the axis direction of the plasma jet.

[0056] Preferably, the frequency of the magnetic field is 50-1000 Hz, for example, it can be 50 Hz, 100 Hz, 200 Hz, 300 Hz, 400 Hz, 500 Hz, 600 Hz, 700 Hz, 800 Hz or 1000 Hz.

[0057] The present invention can adjust and match the spraying particle speed through the magnetic field frequency, thereby improving the coating uniformity.

[0058] Preferably, the spraying power of the atmospheric plasma spraying of the abradable surface layer is 20-40KW, for example, it can be 20KW, 24KW, 28KW, 30KW, 34KW, 38KW or 40KW.

[0059] Preferably, the powder feeding rate of the atmospheric plasma spraying abradable surface layer is 25-35 g / min, for example, it can be 25 g / min, 26 g / min, 30 g / min, 32 g / min, 34 g / min or 35 g / min.

[0060] Preferably, the scanning speed of the atmospheric plasma spraying abradable surface layer is 600-800 mm / s, for example, it can be 600 mm / s, 640 mm / s, 680 mm / s, 700 mm / s, 740 mm / s, 780 mm / s or 800 mm / s.

[0061] Preferably, the spraying distance of the atmospheric plasma spraying abradable surface layer is 100-120 mm, for example, it can be 100 mm, 104 mm, 108 mm, 110 mm, 112 mm, 114 mm, 118 mm or 120 mm.

[0062] The present invention controls the spraying power and scanning speed within the above range to prepare an abradable surface layer with appropriate porosity, which can reduce the friction coefficient of the surface layer and control the wear rate. h-BN is partially oxidized to B during spraying. 2 O 3 , a liquid lubricating film is formed at high temperature, and the friction coefficient is further reduced.

[0063] As a preferred technical solution of the present invention, the preparation method further comprises using pulsed laser to micro-melt the coating surface after the bonding layer, the component transition layer and the high-temperature oxidation resistance layer are sprayed.

[0064] Preferably, the scanning rate of the pulse laser is 8-10 mm / s, for example, it can be 8 mm / s, 8.2 mm / s, 8.4 mm / s, 8.6 mm / s, 9 mm / s, 9.4 mm / s, 9.8 mm / s or 10 mm / s.

[0065] Preferably, the power density of the pulsed laser is 5-8 J / mm 2 , for example, it can be 5J / mm 2 , 5.5J / mm 2 , 6J / mm 2 、6.5J / mm 2 , 7J / mm 2 , 7.5J / mm 2 or 8J / mm 2 wait.

[0066] The present invention adopts laser remelting assisted spraying: after spraying, the surface is micro-melted with a pulsed laser with a power density of 5-8 J / mm² to eliminate interlayer pores and form a metallurgical bonding layer, thereby improving the bonding strength between the bonding layer, the component transition layer, the high-temperature oxidation resistant layer and the self-lubricating transition layer. Laser micro-melting is not used between the self-lubricating transition layer and the abradable surface layer to maintain its porosity and abradability.

[0067] Preferably, the preparation method further comprises the preparation of spray powder, and the preparation of spray powder comprises: mixing the second alloy powder with Al 2 O 3 Nanoparticles are ball-milled to obtain high-temperature resistant oxidation layer powder; the first lubricating phase powder and the first alloy powder are mechanically mixed to obtain self-lubricating transition layer powder; the porous first alloy powder is prepared by a pore-forming agent, and the second lubricating phase powder and the porous first alloy powder are mechanically mixed to obtain a wearable surface layer powder.

[0068] Preferably, the pore former comprises NH 4 HCO 3 .

[0069] Preferably, the preparation of the porous first alloy powder comprises: mixing a pore-forming agent with an initial first alloy powder and dispersing the mixture into water, spray-drying the mixture and granulating the mixture to prepare the porous first alloy powder.

[0070] Preferably, the porous first alloy powder is spherical.

[0071] Preferably, the particle size of the initial first alloy powder is 1-3 μm, for example, 1 μm, 1.4 μm, 1.8 μm, 2 μm, 2.4 μm, 2.8 μm or 3 μm.

[0072] Preferably, the mass ratio of the pore former to the initial first alloy powder is 1:(8-9.5), for example, it can be 1:8, 1:8.2, 1:8.4, 1:8.6, 1:8.8, 1:9 or 1:9.5, etc.

[0073] Preferably, the particle size of the h-BN powder is 1-3 μm, for example, 1 μm, 1.4 μm, 1.8 μm, 2 μm, 2.4 μm, 2.8 μm or 3 μm.

[0074] As a preferred technical solution of the present invention, the annealing post-treatment includes heating under vacuum conditions, the heating temperature is 650-900°C, for example, it can be 650°C, 690°C, 730°C, 770°C, 810°C, 850°C or 900°C, etc.; after the heating is completed, the furnace is cooled to 100-300°C, for example, it can be 100°C, 140°C, 180°C, 200°C, 240°C, 280°C or 300°C, etc.; after the furnace is cooled, it is air-cooled to room temperature.

[0075] Preferably, the heating temperature rise rate is 4-6°C / min, for example, it can be 4°C / min, 4.2°C / min, 4.4°C / min, 4.8°C / min, 5°C / min, 5.2°C / min, 5.8°C / min or 6°C / min.

[0076] Preferably, the vacuum degree of the vacuum condition is 5×10 -4 -1×10 -3 Pa, for example, can be 0.5×10 -3 Pa, 0.6×10 -3 Pa, 0.7×10 -3 Pa, 0.8×10 -3 Pa or 1×10 -3 Pa et al.

[0077] The present invention heats the sprayed coating under vacuum conditions, preferably the heating temperature and vacuum degree are within the above ranges, the Al element in the NiCrAlY matrix reacts with the residual oxygen during the spraying process and in the furnace to cooperate with the aluminum oxide nanoparticles in the coating to form a dense Al 2 O 3 film, further inhibiting substrate oxidation.

[0078] Compared with the prior art, the present invention has at least the following beneficial effects: (1) The multilayer gradient coating provided by the present invention realizes the integration of high temperature oxidation resistance, wear resistance and self-lubrication by sequentially arranging multiple layers of coatings with different functions, and the synergistic effect between the multiple layers of coatings. The friction coefficient is reduced by 50% compared with the traditional coating, and the wear rate of the abradable surface layer is ≤5×10 -6 mm 3 / N•m, 1000℃ / 200h oxidation weight gain ≤3 mg / cm 2 Reduced by 30%, leakage ≤ 3% (much lower than the industry standard ≤ 5%); (2) The multilayer gradient coating provided by the present invention reduces the difference in thermal expansion coefficient between layers through the coordination of the components between the layers, avoids the thermal mismatch between the layers, and improves the matching of the thermal expansion coefficient of the coating, thereby increasing the thermal shock cycle life of the coating by 50%. It solves the performance splitting problem of a single coating and the thermal stress problem of a multilayer composite coating, and provides a long-lasting and reliable high-temperature sealing coating. DETAILED DESCRIPTION

[0079] For the convenience of understanding the present invention, the present invention lists the following embodiments. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0080] Embodiment 1: The present embodiment provides a multilayer gradient coating with high temperature oxidation resistance, wear resistance and self-lubricating functions, wherein the multilayer gradient coating includes a bonding layer, a composition transition layer, a high temperature oxidation resistance layer, a self-lubricating transition layer and a wearable surface layer in sequence from the substrate to the surface; the bonding layer is Ni-22Cr-10Al-1Y powder; the composition transition layer includes Ni-22Cr-10Al-1Y powder and Co-32Ni-21Cr-8Al-0.5Y powder; the high temperature oxidation resistance layer includes Co-32Ni-21Cr-8Al-0.5Y powder and 5% Al 2 O 3 Nanoparticles; the self-lubricating transition layer comprises Ni-22Cr-10Al-1Y powder and 30% Ag and CaF 2 Mixed powder, Ag and CaF in the mixed powder 2 The mass ratio of the abradable surface layer is 3:1; the abradable surface layer includes porous Ni-22Cr-10Al-1Y powder and 4% h-BN powder. The particle size of the Ni-22Cr-10Al-1Y powder is 15-45μm, the particle size of the Al2O3 nanoparticles is 50nm, the particle size of the Co-32Ni-21Cr-8Al-0.5Y powder is 15-45μm, the Ag and CaF 2 The particle size of the mixed powder is 10-38 μm, and the particle size of the porous Ni-22Cr-10Al-1Y powder is 25-53 μm.

[0081] The multi-layer gradient coating is prepared by the following method: (1) Powder preparation: Co-32Ni-21Cr-8Al-0.5Y powder was mixed with Al 2 O 3 The nanoparticles were mixed by high-energy ball milling at 300 RPM for 8 h to obtain a high-temperature resistant oxide layer powder; Ag powder and CaF 2 The powders were mixed in a mass ratio of 3:1 to mix Ag and CaF 2 The mixed powder and Ni-22Cr-10Al-1Y powder were mechanically mixed in a V-type mixer at a mass ratio of 3:7 for 2 hours to obtain a self-lubricating transition layer powder; NH 4 HCO 3 The mixture was mixed with the initial Ni-22Cr-10Al-1Y powder with a particle size of 1-3 μm at a mass ratio of 1:9 and then dispersed in water, spray dried and granulated to prepare spherical porous Ni-22Cr-10Al-1Y powder, and the average porosity of the porous Ni-22Cr-10Al-1Y powder was 30%. 4wt% h-BN powder was mechanically mixed with porous Ni-22Cr-10Al-1Y powder in a V-type mixer for 2 hours to obtain an abradable surface powder; (2) Coating spraying: The Inconel 718 substrate was sandblasted with 120 mesh white corundum. The surface roughness of the substrate was 5 μm after sandblasting. The substrate was ultrasonically cleaned with a mixed solution of acetone and ethanol for 5 min. The bonding layer was sprayed by supersonic plasma method, with a spraying power of 42KW, an oxygen flow rate of 800 L / h, a propane flow rate of 280 SLPM, a spraying distance of 130mm, a powder feeding rate of 35g / min, and a total spraying thickness of 60μm; The surface of the bonding layer is micro-melted using pulsed laser, the scanning rate of the pulsed laser is 9mm / s, and the power density of the pulsed laser is 7J / mm²; The supersonic plasma method was used to spray the component transition layer. Double-barrel powder feeding was used to adjust the Co-32Ni-21Cr-8Al-0.5Y powder content from 0% to 100%. The spraying power was 42KW, the oxygen flow rate was 800 L / h, the propane flow rate was 280 SLPM, the spraying distance was 130mm, the powder feeding rate was 35g / min, and the total spraying thickness was 60μm. The pulse laser is used to micro-melt the surface of the composition transition layer. The scanning rate of the pulse laser is 9 mm / s and the power density of the pulse laser is 7 J / mm. 2 ; The high temperature oxidation resistant layer was sprayed by supersonic plasma method, with a spraying power of 42KW, an oxygen flow rate of 800 L / h, a propane flow rate of 280 SLPM, a spraying distance of 130mm, a powder feeding rate of 35 g / min, and a total spraying thickness of 120μm. Pulse laser is used to combat micro-melting of the high-temperature oxide layer. The scanning rate of the pulse laser is 9 mm / s and the power density of the pulse laser is 7 J / mm. 2 ; Magnetic field assisted supersonic plasma spraying of self-lubricating transition layer, the magnetic field direction is perpendicular to the plasma jet direction, the magnetic field intensity is 0.45T, the spraying power is 42KW, the oxygen flow rate is 800 L / h, the propane flow rate is 280 SLPM, the spraying distance is 130mm, the powder feeding rate is 35 g / min, and the total spraying thickness is 60μm; Atmospheric plasma spraying can abrade the surface layer, the spraying power is 35 kW, the powder feeding rate is 25 g / min, the spraying distance is 110 mm, the scanning speed is 750 mm / s, the total spraying thickness is 100 μm, and the coating porosity is 22%; (3) Post-annealing treatment: The sprayed substrate was placed in a vacuum of 1×10 -3 The mixture was heated to 700°C in a furnace of 1000 Pa, kept at this temperature for 3 hours, then cooled to 300°C, and then air-cooled to room temperature to obtain the multi-layer gradient coating with high temperature oxidation resistance, wear resistance and self-lubricating function.

[0082] Embodiment 2: The present embodiment provides a multilayer gradient coating with high temperature oxidation resistance, wear resistance and self-lubricating functions, wherein the multilayer gradient coating includes a bonding layer, a composition transition layer, a high temperature oxidation resistance layer, a self-lubricating transition layer and a wearable surface layer in sequence from the substrate to the surface; the bonding layer is Ni-22Cr-10Al-1Y powder; the composition transition layer includes Ni-22Cr-10Al-1Y powder and Co-32Ni-21Cr-8Al-0.5Y powder; the high temperature oxidation resistance layer includes Co-32Ni-21Cr-8Al-0.5Y powder and 3% Al 2 O 3 Nanoparticles; the self-lubricating transition layer includes Ni-22Cr-10Al-1Y powder and 20% Ag-CaF 2 Mixed powder, Ag and CaF in the mixed powder 2 The mass ratio of is 2:1; the wearable surface layer comprises porous Ni-22Cr-10Al-1Y powder and 3% h-BN powder. The particle size of the Ni-22Cr-10Al-1Y powder is 15-45μm, and the Al 2 O 3The particle size of the nanoparticles is 10 nm, the particle size of the Co-32Ni-21Cr-8Al-0.5Y powder is 15-45 μm, and the Ag and CaF 2 The particle size of the mixed powder is 10-38 μm, and the particle size of the porous Ni-22Cr-10Al-1Y powder is 25-53 μm.

[0083] The multi-layer gradient coating is prepared by the following method: (1) Powder preparation: Co-32Ni-21Cr-8Al-0.5Y powder was mixed with Al 2 O 3 The nanoparticles were mixed by high-energy ball milling at 300 RPM for 8 h to obtain a high-temperature resistant oxide layer powder; Ag and CaF 2 Ag and CaF were mixed in a mass ratio of 2:1. 2 Mix the powders to make Ag and CaF 2 The mixed powder and Ni-22Cr-10Al-1Y powder were mechanically mixed in a V-type mixer at a mass ratio of 2:8 for 2 hours to obtain a self-lubricating transition layer powder; NH 4 HCO 3 The mixture was mixed with the initial Ni-22Cr-10Al-1Y powder with a particle size of 1-3 μm at a mass ratio of 1:8.5 and then dispersed in water, spray dried and granulated to prepare spherical porous Ni-22Cr-10Al-1Y powder, and the average porosity of the porous Ni-22Cr-10Al-1Y powder was 40%. The 3wt% h-BN powder was mechanically mixed with the porous Ni-22Cr-10Al-1Y powder in a V-type mixer for 2 hours to obtain an abradable surface powder; (2) Coating spraying: The Inconel 718 substrate was sandblasted with 120 mesh white corundum. The surface roughness of the substrate was 4 μm after sandblasting. The substrate was ultrasonically cleaned with a mixed solution of acetone and ethanol for 5 min. The bonding layer was sprayed by supersonic plasma method, with a spraying power of 40KW, an oxygen flow rate of 750 L / h, a propane flow rate of 250 SLPM, a spraying distance of 120mm, a powder feeding rate of 30 g / min, and a total spraying thickness of 50μm; The surface of the bonding layer is micro-melted by pulse laser. The scanning rate of the pulse laser is 8 mm / s and the power density of the pulse laser is 5 J / mm. 2 ; The supersonic plasma spraying composition transition layer uses double-barrel powder feeding, and the Co-32Ni-21Cr-8Al-0.5Y powder content is adjusted from 0% to 100% in a gradient transition. The spraying power is 40KW, the oxygen flow rate is 750 L / h, the propane flow rate is 250 SLPM, the spraying distance is 120mm, the powder feeding rate is 30 g / min, and the total spraying thickness is 50μm. The pulse laser is used to micro-melt the surface of the composition transition layer. The scanning rate of the pulse laser is 8mm / s and the power density of the pulse laser is 5J / mm 2 ; The high temperature oxidation resistant layer was sprayed by supersonic plasma method, with a spraying power of 40KW, an oxygen flow rate of 750 L / h, a propane flow rate of 250 SLPM, a spraying distance of 120mm, a powder feeding rate of 30 g / min, and a total spraying thickness of 100μm. Pulse laser is used to combat micro-melting of the high-temperature oxide layer. The scanning rate of the pulse laser is 8 mm / s and the power density of the pulse laser is 5 J / mm. 2 ; The self-lubricating transition layer was sprayed by magnetic field assisted supersonic plasma method. The magnetic field direction was perpendicular to the plasma jet direction, the magnetic field intensity was 0.4T, the spraying power was 40KW, the oxygen flow rate was 750 L / h, the propane flow rate was 250 SLPM, the spraying distance was 120mm, the powder feeding rate was 30 g / min, and the total spraying thickness was 50μm. Atmospheric plasma spraying can abrade the surface layer, the spraying power is 35 kW, the powder feeding rate is 35 g / min, the spraying distance is 100 mm, the scanning speed is 750 mm / s, the total spraying thickness is 80 μm, and the coating porosity is 15%; (3) Post-annealing treatment: The sprayed substrate was placed in a vacuum of 0.8×10 -3 The furnace body of the invention is heated to 650°C in a temperature-controlled furnace, kept at this temperature for 3 hours, then cooled to 100°C in the furnace, and then air-cooled to room temperature, thereby obtaining the multi-layer gradient coating having the functions of high temperature oxidation resistance, wear resistance and self-lubrication.

[0084] Embodiment 3: The present embodiment provides a multilayer gradient coating with high temperature oxidation resistance, wear resistance and self-lubricating functions, wherein the multilayer gradient coating includes a bonding layer, a component transition layer, a high temperature oxidation resistance layer, a self-lubricating transition layer and a wearable surface layer in sequence from the substrate to the surface; the bonding layer is Ni-22Cr-10Al-1Y powder; the component transition layer includes Ni-22Cr-10Al-1Y powder and Co-32Ni-21Cr-8Al-0.5Y powder; the high temperature oxidation resistance layer includes Co-32Ni-21Cr-8Al-0.5Y powder and 10% Al2O3 nanoparticles; the self-lubricating transition layer includes Ni-22Cr-10Al-1Y powder and 40% Ag-CaF 2 Mixed powder, Ag and CaF in the mixed powder 2 The mass ratio of the Ni-22Cr-10Al-1Y powder is 4:1; the wearable surface layer includes porous Ni-22Cr-10Al-1Y powder and 5% h-BN powder. The particle size of the Ni-22Cr-10Al-1Y powder is 15-45μm, and the Al 2 O 3 The particle size of the nanoparticles is 60nm, the particle size of the Co-32Ni-21Cr-8Al-0.5Y powder is 15-45μm, and the Ag and CaF 2 The particle size of the mixed powder is 10-38 μm, and the particle size of the porous Ni-22Cr-10Al-1Y powder is 25-53 μm.

[0085] The multi-layer gradient coating is prepared by the following method: (1) Powder preparation: Co-32Ni-21Cr-8Al-0.5Y powder was mixed with Al 2 O 3 The nanoparticles were mixed by high-energy ball milling at 300 RPM for 8 h to obtain a high-temperature resistant oxide layer powder; Ag and CaF 2 Ag and CaF were mixed in a mass ratio of 4:1. 2 Mix the powders to make Ag and CaF 2 The mixed powder and Ni-22Cr-10Al-1Y powder were mechanically mixed in a V-type mixer at a mass ratio of 4:6 for 2 hours to obtain a self-lubricating transition layer powder; NH 4 HCO 3The mixture was mixed with the initial Ni-22Cr-10Al-1Y powder with a particle size of 1-3 μm at a mass ratio of 1:9.5 and then dispersed in water, spray dried and granulated to prepare spherical porous Ni-22Cr-10Al-1Y powder, and the average porosity of the porous Ni-22Cr-10Al-1Y powder was 20%. 5wt% h-BN powder was mechanically mixed with porous Ni-22Cr-10Al-1Y powder in a V-type mixer for 2 hours to obtain an abradable surface powder; (2) Coating spraying: The Inconel 718 substrate was sandblasted with 120 mesh white corundum. The surface roughness of the substrate was 6 μm after sandblasting. The substrate was ultrasonically cleaned with a mixed solution of acetone and ethanol for 5 min. The bonding layer was sprayed by supersonic plasma method, with a spraying power of 45KW, an oxygen flow rate of 850 L / h, a propane flow rate of 350 SLPM, a spraying distance of 150mm, a powder feeding rate of 40 g / min, and a total spraying thickness of 80μm; The surface of the bonding layer is micro-melted by pulse laser. The scanning rate of the pulse laser is 10 mm / s and the power density of the pulse laser is 8 J / mm. 2 ; The supersonic plasma method was used to spray the component transition layer. Double-barrel powder feeding was used to adjust the Co-32Ni-21Cr-8Al-0.5Y powder content from 0% to 100%. The spraying power was 45KW, the oxygen flow rate was 850 L / h, the propane flow rate was 350 SLPM, the spraying distance was 150mm, the powder feeding rate was 40 g / min, and the total spraying thickness was 80μm. The pulse laser is used to micro-melt the surface of the composition transition layer. The scanning rate of the pulse laser is 10 mm / s and the power density of the pulse laser is 8 J / mm. 2 ; The high temperature oxidation resistant layer was sprayed by supersonic plasma method, with a spraying power of 45KW, an oxygen flow rate of 850 L / h, a propane flow rate of 350 SLPM, a spraying distance of 150mm, a powder feeding rate of 40 g / min, and a total spraying thickness of 150μm. Pulse laser is used to combat micro-melting of the high-temperature oxide layer. The scanning rate of the pulse laser is 10 mm / s and the power density of the pulse laser is 8 J / mm. 2 ; The self-lubricating transition layer was sprayed by magnetic field assisted supersonic plasma method. The magnetic field direction was perpendicular to the plasma jet direction. The magnetic field intensity was 0.5T. The spraying power was 45KW. The oxygen flow rate was 850 L / h. The propane flow rate was 350 SLPM. The spraying distance was 150mm. The powder feeding rate was 40 g / min. The total spraying thickness was 80μm. Atmospheric plasma spraying can abrade the surface layer, the spraying power is 40 kW, the powder feeding rate is 35 g / min, the spraying distance is 120 mm, the scanning speed is 800 mm / s, the spraying thickness is 120 μm, and the coating porosity is 30%; (3) Post-annealing treatment: The sprayed substrate was placed in a vacuum of 0.5×10 -3 The mixture was heated to 900°C in a furnace of 10000 Pa, kept at this temperature for 3 hours, then cooled to 200°C, and then air-cooled to room temperature to obtain the multi-layer gradient coating with high temperature oxidation resistance, wear resistance and self-lubricating function.

[0086] Embodiment 4: This embodiment provides a multilayer gradient coating with high temperature oxidation resistance, wear resistance and self-lubricating functions. The multilayer gradient coating is the same as Embodiment 1 except that the mass fraction of Al2O3 nanoparticles in the high temperature oxidation resistance layer is 1%.

[0087] Embodiment 5: This embodiment provides a multi-layer gradient coating with high temperature oxidation resistance, wear resistance and self-lubrication functions. The multi-layer gradient coating has Al in the high temperature oxidation resistance layer. 2 O 3 Except that the mass fraction of the nanoparticles is 15%, the rest is the same as that of Example 1.

[0088] Embodiment 6: This embodiment provides a multi-layer gradient coating with high temperature oxidation resistance, wear resistance and self-lubricating function. The multi-layer gradient coating has Ag and CaF in the self-lubricating transition layer. 2 Except that the mass fraction of the mixed powder is 15%, the rest is the same as that of Example 1.

[0089] Embodiment 7: This embodiment provides a multi-layer gradient coating with high temperature oxidation resistance, wear resistance and self-lubricating function. The multi-layer gradient coating has Ag and CaF in the self-lubricating transition layer. 2 Except that the mass fraction of the mixed powder is 45%, the rest is the same as that of Example 1.

[0090] Embodiment 8: This embodiment provides a multi-layer gradient coating with high temperature oxidation resistance, wear resistance and self-lubricating function. 2 Ag and CaF in mixed powder 2 Except that the mass ratio of is 1:1, the rest is the same as that in Example 1.

[0091] Embodiment 9: This embodiment provides a multi-layer gradient coating with high temperature oxidation resistance, wear resistance and self-lubricating function. 2 Ag and CaF in mixed powder 2 Except that the mass ratio of is 5:1, the rest is the same as that in Example 1.

[0092] Embodiment 10: This embodiment provides a multilayer gradient coating with high temperature oxidation resistance, abrasion resistance and self-lubricating functions. The multilayer gradient coating is the same as that in Embodiment 1 except that the mass fraction of h-BN powder in the abradable surface layer is 1%.

[0093] Embodiment 11: This embodiment provides a multilayer gradient coating with high temperature oxidation resistance, abrasion resistance and self-lubricating functions. The multilayer gradient coating is the same as Embodiment 1 except that the mass fraction of h-BN powder in the abradable surface layer is 10%.

[0094] Embodiment 12: This embodiment provides a multilayer gradient coating with high temperature oxidation resistance, abrasion resistance and self-lubricating functions. Except that the porosity of the abradable surface layer is 10%, the rest of the multilayer gradient coating is the same as that of Embodiment 1.

[0095] Embodiment 13: This embodiment provides a multilayer gradient coating with high temperature oxidation resistance, abrasion resistance and self-lubricating functions. Except that the porosity of the abradable surface layer is 40%, the rest of the multilayer gradient coating is the same as that of Embodiment 1.

[0096] Embodiment 14: This embodiment provides a multilayer gradient coating with high temperature oxidation resistance, wear resistance and self-lubricating functions. The multilayer gradient coating is the same as Embodiment 1 except that no annealing post-treatment is performed during the preparation process.

[0097] Embodiment 15: This embodiment provides a multi-layer gradient coating with high temperature oxidation resistance, wear resistance and self-lubricating function. The multi-layer gradient coating does not contain Al except for the high temperature oxidation resistance layer. 2 O 3 Except for the nanoparticles, everything else is the same as in Example 1.

[0098] Embodiment 16: This embodiment provides a multilayer gradient coating with high-temperature oxidation resistance, wear resistance and self-lubricating functions. Except that the high-temperature oxidation resistance layer replaces the Co-32Ni-21Cr-8Al-0.5Y powder with Ni-22Cr-10Al-1Y powder, the rest of the multilayer gradient coating is the same as Example 1.

[0099] Embodiment 17: This embodiment provides a multilayer gradient coating with high-temperature oxidation resistance, wear resistance and self-lubricating functions. The multilayer gradient coating is the same as Example 1 except that the porous Ni-22Cr-10Al-1Y powder is replaced by non-porous Ni-22Cr-10Al-1Y powder in the abradable surface layer.

[0100] Embodiment 18: This embodiment provides a multi-layer gradient coating with high temperature oxidation resistance, wear resistance and self-lubrication functions. The multi-layer gradient coating has Al in the high temperature oxidation resistance layer. 2 O 3 Except that the particle size of the nanoparticles is 5 nm, the rest is the same as that of Example 1.

[0101] Embodiment 19: This embodiment provides a multi-layer gradient coating with high temperature oxidation resistance, wear resistance and self-lubrication functions. The multi-layer gradient coating has Al in the high temperature oxidation resistance layer. 2 O 3 Except that the particle size of the nanoparticles is 65 nm, the rest is the same as that of Example 1.

[0102] Embodiment 20: This embodiment provides a multilayer gradient coating with high temperature oxidation resistance, wear resistance and self-lubricating functions. The multilayer gradient coating is the same as Embodiment 1 except that pulsed laser is not used to micro-melt the coating surface.

[0103] Comparative Example 1: This comparative example provides a coating, which is the same as Example 1 except that it does not include a high-temperature oxidation resistant layer.

[0104] Comparative Example 2: This comparative example provides a coating, which is the same as Example 1 except that it does not include a self-lubricating transition layer.

[0105] Comparative Example 3: This comparative example provides a coating, which is the same as Example 1 except that the coating does not include an abradable surface layer and the self-lubricating transition layer is used as the surface layer to directly contact the wear part.

[0106] Comparative Example 4: This comparative example provides a coating, which is the same as Example 1 except that it does not include a composition transition layer.

[0107] Test method: The coatings of Examples 1-13 and Comparative Examples 1-6 were subjected to a gas turbine comb seal ring coating performance test. According to ASTM G99 (pin-disc or ring-disc wear test standard), the test temperature was 900°C, the rotation speed was 12000 RPM, the wear piece was made of Inconel 718 cemented carbide, the load was 50N, the contact between the wear piece and the coating was line contact, the test time was 2-5h, and the volume wear rate of the sample surface was evaluated. According to ASTM G54 (material high temperature oxidation test standard), the test temperature was 900°C, the test atmosphere was static air or simulated gas (containing O 2 , H 2 O、CO 2 ), test time: 100-500 hours (simulating long-term service), evaluate the oxidation weight gain of the sample. According to API 617 (gas turbine industry sealing performance specification), test the sealing performance of the sample, test temperature: 900℃, pressure difference of 0.5-1.5 MPa (simulating the pressure difference of the gas turbine compressor / turbine section), nitrogen or air medium, dynamically adjust the grinding gap (initial gap 50-100μm, simulate the sealing performance after the comb teeth are worn), and evaluate the leakage. ASTM C633 tests the bonding strength between the high-temperature oxidation layer of the coating and the self-lubricating transition layer.

[0108] Test results: The test results are shown in Table 1.

[0109] Table 1

[0110] The test results show that: (1) It can be seen from Examples 1 to 3 that the present invention can achieve reduced friction coefficient, controllable surface wear rate, good oxidation resistance and excellent sealing performance through the synergistic effect of the bonding layer, high temperature oxidation resistant layer, self-lubricating transition layer and abradable surface layer. The friction coefficient in the steady state stage is between 0.18 and 0.22, which is 50% lower than that of the traditional coating, and the wear rate of the abradable surface layer is ≤5×10 -6 mm 3 / N•m, 1000℃ / 200h oxidation weight gain ≤3 mg / cm 2 , leakage ≤3% (much lower than the industry standard ≤5%); (2) It can be seen from Examples 1 and 4-11 that the present invention can better balance the high temperature oxidation resistance, wear resistance and self-lubricating functions by further optimizing the component content of each layer, so as to achieve a lower friction coefficient, a smaller wear rate, and a smaller interlayer thermal stress. 2 O 3If the content of nanoparticles is too low, the oxidation weight gain will increase by 50%, and the high temperature oxidation resistance will decrease. 2 O 3 The content of nanoparticles is too high, and the bonding strength between the high temperature oxidation resistant layer and the self-lubricating transition layer decreases from 57MPa to 38MPa. 2 The content of the mixed powder is too low, the friction coefficient increases and the surface wear rate increases. 2 The content of the mixed powder is too high, and the bonding strength between the high temperature oxidation resistant layer and the self-lubricating transition layer decreases from 57MPa to 28MPa. 2 When the mass ratio of is too high or too low, the friction coefficient of the coating increases and the surface wear rate increases. When the content of h-BN powder in the abradable surface layer is too low or too high, the friction coefficient of the coating increases and the surface wear rate increases; (3) It can be seen from Example 1 and Examples 12-13 and 17 that the present invention improves the lubricity of the abradable surface and reduces the wear rate of the surface by optimizing the pore structure of the abradable surface. When the porosity of the surface is too low, the wear rate decreases but the friction coefficient increases significantly. When the porosity of the surface is too high, the wear rate increases significantly. When porous powder is not used, the friction coefficient of the coating increases and the surface wear rate increases. It can be seen from Example 1 and Examples 15-16 that the present invention greatly improves the high-temperature oxidation resistance by introducing alumina particles and Co into the high-temperature oxidation resistance layer. It can be seen from Example 1 and Examples 18-19 that the present invention further improves the high-temperature oxidation resistance by optimizing the particle size of the alumina particles. It can be seen from Example 1 and Example 20 that the present invention further improves the bonding force between layers by means of laser micro-melting; (4) It can be seen from Example 1 and Comparative Examples 1-4 that the present invention achieves high-temperature oxidation resistance, abrasion resistance and self-lubricating functions through the synergistic effect of multiple layers of functional coatings, and can obtain a lower friction coefficient and high-temperature oxidation resistance and sealing effect. When any one of the layers is missing, the technical effect of the present application cannot be achieved.

[0111] In summary, the present invention integrates high-temperature oxidation resistance, self-lubrication and abrasion resistance into the coating through the setting of a multi-layer gradient composite structure, breaks through the performance contradiction problem of traditional single coatings, overcomes the peeling failure problem caused by the difference in thermal expansion coefficients of multi-layer coatings, and provides a multifunctional and highly stable coating through the synergistic effect of various types of coatings and the optimization of materials and processes.

[0112] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A multilayer gradient coating with high temperature oxidation resistance, wear resistance and self-lubricating function, characterized in that: The multi-layer gradient coating includes a bonding layer, a component transition layer, a high temperature oxidation resistance layer, a self-lubricating transition layer and an abradable surface layer in sequence from the substrate to the surface; The bonding layer is a first alloy powder; the composition transition layer includes a first alloy powder and a second alloy powder; the high temperature oxidation resistance layer includes a second alloy powder and Al2O3 nanoparticles; the self-lubricating transition layer includes a first alloy powder and a first lubricating phase powder; the abradable surface layer includes a porous first alloy powder and a second lubricating phase powder; The first alloy powder includes NiCrAlY powder; the first lubricating phase powder in the self-lubricating transition layer includes Ag powder and CaF2 powder; the second alloy powder includes CoNiCrAlY powder; and the second lubricating phase powder includes h-BN powder.

2. The multi-layer gradient coating according to claim 1, characterized in that: The volume content of the second alloy powder in the composition transition layer increases from 0% to 100% from the bonding layer to the high temperature oxidation resistance layer.

3. The multi-layer gradient coating according to claim 1, characterized in that: The mass fraction of Al2O3 nanoparticles in the high temperature oxidation resistant layer is 3-10%.

4. The multi-layer gradient coating according to claim 1, characterized in that: The mass fraction of the first lubricating phase powder in the self-lubricating transition layer is 20-40%.

5. The multi-layer gradient coating according to claim 1, characterized in that: The mass fraction of the second lubricating phase powder in the abradable surface layer is 3%-5%.

6. The multi-layer gradient coating according to claim 1, characterized in that: The average porosity of the porous first alloy powder is 20-40%, and the porosity of the abradable surface layer is 15-30%.

7. A method for preparing a multilayer gradient coating according to any one of claims 1 to 6, characterized in that: The preparation method comprises: spraying a bonding layer, a component transition layer and a high temperature oxidation resistance layer on a pretreated substrate in sequence by supersonic plasma, spraying a self-lubricating transition layer by magnetic field-assisted supersonic plasma, and spraying an abradable surface layer by atmospheric plasma.

8. The preparation method according to claim 8, characterized in that: The preparation method also includes using pulse laser to micro-melt the coating surface after the bonding layer, the component transition layer and the high-temperature oxidation resistance layer are sprayed.

9. The preparation method according to claim 8, characterized in that: The preparation method further comprises an annealing post-treatment, wherein the annealing post-treatment comprises heating under vacuum conditions, and the heating temperature is 650-900°C.

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