Preparation process of corrosion-resistant wear-resistant self-lubricating coating for aero-engine

Abstract

According to the preparation process of the corrosion-resistant and wear-resistant self-lubricating coating for the aero-engine, the high-entropy alloy / fluoride-containing chromium carbide wear-resistant self-lubricating coating is prepared by adopting a high velocity oxy-fuel spraying process, and the coating is uniform in structure, has good wear-resistant lubricating performance and corrosion resistance and also has excellent bonding strength and anti-stripping capacity; niCrAlYSi is sprayed on the surface of the metal matrix at supersonic speed to serve as a bottom layer of the corrosion-resistant and wear-resistant coating, so that the matching property, corrosion resistance and oxidation resistance of the coating and the metal matrix are improved; and high-entropy alloy / fluoride-containing chromium carbide is sprayed by adopting hypersonic flame to serve as a wear-resistant self-lubricating surface layer. The method has the advantages that the oxidation resistance and corrosion resistance of the coating are integrally improved, and the prepared coating keeps the original good-wear-resistance organization structure of metal ceramic. The service life of a part can be prolonged by 2-10 times due to the frictional wear performance and the like, and the composite material can also be applied to other power machinery fields and has a very wide market prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and in particular to a process for preparing a corrosion-resistant, wear-resistant, self-lubricating coating for an aero-engine. Background Art

[0002] As the thrust-to-weight ratio of aircraft engines continues to increase, the requirements for sealing the internal gas paths are becoming increasingly stringent. Compared to traditional grate seals, brush seals offer a compact design, lightweight design, and ease of replacement. Their most significant advantage is that their gas leakage is reduced to only 1 / 5 to 1 / 10 of that of grate seals. Consequently, brush seals have become widely used in turbomachinery, including aircraft engines, industrial gas turbines, and steam turbines, significantly improving engine performance.

[0003] A typical brush seal mainly consists of a brush ring and a sealing ring, and the surface of the sealing ring is coated with a wear-resistant coating to improve its wear resistance. Due to the high air or gas pressure, wide temperature range, and high heat generated by ultra-high rotation friction in aircraft engines, the wear-resistant coating of the sealing ring under working conditions may develop defects such as cracks, crazing, and falling blocks, which seriously affect the sealing effect. Especially for engines docked and used in marine environments, the wear-resistant and self-lubricating coating of the brush sealing ring needs to have not only wear resistance over a wide temperature range, but also good corrosion resistance. Therefore, there is an urgent need to explore new corrosion-resistant, wear-resistant, self-lubricating coating systems and preparation processes suitable for brush seals.

[0004] Currently, wear-resistant coatings for sealing rings developed domestically and internationally are typically nickel-chromium / chromium carbide (NiCr / Cr3C2) wear-resistant coatings produced using a thermal spraying process, as well as composite coatings with reinforcements such as Cr7C3 and (Cr,W)C carbides, or lubricating phases such as NbSe2, WS2, calcium fluoride, and graphite. However, existing technologies limit the applicable temperature range of these coatings and their corrosion resistance is weak, failing to meet the high wear resistance, self-lubrication, and corrosion resistance requirements of engines during service. Summary of the Invention

[0005] The present invention designs a corrosion-resistant, wear-resistant, self-lubricating coating. A high-entropy alloy / fluoride-containing chromium carbide (NiCoFeCrAl / Cr3C2.BaF2·CaF2) wear-resistant, self-lubricating coating is prepared by a supersonic flame spraying process. The coating has a uniform structure, good wear-resistant, lubricating and corrosion-resistant properties, and excellent bonding strength and spalling resistance.

[0006] The purpose of this invention is to develop a corrosion-resistant, wear-resistant, self-lubricating high-entropy alloy coating that exhibits excellent performance in the temperature range from room temperature to 700°C. This coating possesses excellent corrosion resistance, wear resistance, and bonding strength. It can be used not only for sealing and protecting brush seals in aircraft engines operating in marine environments, but also for applying wear-resistant coatings to the abutting wear areas of other engine components, as well as coating various types of ground-based gas turbines and vulnerable components in the energy and power industries.

[0007] The present invention adopts a dual-layer structure system to improve the overall compatibility between the coating and the substrate, and between the coatings, as well as the coating's oxidation resistance, corrosion resistance, and thermal cycling performance, thereby reducing flaking during use. Specifically, NiCrAlYSi is supersonic-sprayed on the metal substrate as a corrosion-resistant and wear-resistant base layer, improving the compatibility between the coating and the metal substrate and its corrosion and oxidation resistance. A high-entropy alloy / fluoride-containing chromium carbide (NiCoFeCrAl / Cr3C2.BaF2·CaF2) supersonic flame sprayed top layer is then applied to improve the wear-resistant coating's oxidation and corrosion resistance, reduce its friction coefficient, improve friction performance, and ensure satisfactory thermal cycling performance.

[0008] The specific technical solutions are as follows:

[0009] (1) Preparation of wear-resistant self-lubricating coating structural system materials

[0010] Ceramic base material: The present invention adopts NiCrAlYSi powder prepared by vacuum atomization method to enhance the bonding strength between the coating and the substrate and the coating, and improve the matching between the coating and the metal substrate and the coating.

[0011] Surface layer material: The present invention adopts a high entropy alloy / fluoride-containing chromium carbide (NiCoFeCrAl / Cr3C2.BaF2·CaF2) surface layer to improve the corrosion resistance of the wear-resistant self-lubricating coating.

[0012] (2) Design of wear-resistant self-lubricating coating structure system

[0013] The coating is prepared by thermal spraying. As the thickness increases, the thermal stress in the coating will increase. At the same time, under the alternating hot and cold environment of the engine, large residual thermal stress is also generated in the coating. Coupled with the high-speed friction of the brush wire, the coating's anti-stripping ability is adversely affected. In order to improve the thermal shock resistance life of the wear-resistant self-lubricating coating, the present invention adopts a double-layer structure, corrosion-resistant and wear-resistant self-lubricating coating, and adopts supersonic spraying NiCrAlYSi as the corrosion-resistant and wear-resistant coating bottom layer to improve the matching of the coating system and the corrosion resistance and oxidation resistance; and adopts supersonic flame spraying NiCoFeCrAl / Cr3C2.BaF2·CaF2 as the wear-resistant self-lubricating surface layer. The double-layer corrosion-resistant and wear-resistant self-lubricating coating designed by this patent has a uniform coating structure, good wear-resistant and lubricating properties and corrosion resistance, and also has excellent bonding strength and anti-stripping ability.

[0014] (3) Coating preparation process

[0015] Supersonic flame spraying (HVOF) is a high-velocity flame spraying technology characterized by high flame speeds and low temperatures. HVOF is particularly advantageous for spraying metal coatings and carbide ceramic coatings. The high particle velocity facilitates high coating density and good bonding strength, thereby enhancing high-temperature oxidation and corrosion resistance. The low flame temperature effectively inhibits or reduces the decomposition and ablation of hard phases such as carbides and lubricating phases such as fluorides during the spraying process, ensuring that the resulting coating retains the inherent wear resistance of the carbide ceramic and the inherent lubricity of the fluoride.

[0016] The process flow is:

[0017] 1. Incoming inspection: Check whether there are defects such as pores and cracks on the surface of the substrate;

[0018] 2. Use acetone to remove oil stains;

[0019] 3. Appearance inspection: Visually inspect the surface of the substrate to see if there is any oil stain on the sprayed surface;

[0020] 4. Sandblasting protection: The non-spray coating area is protected with metal and rubber tooling or protective tape;

[0021] 5. Dry sand blowing: Alumina sand is used to roughen the surface of the substrate, and the surface roughness of the substrate reaches 2.0-2.5μm;

[0022] 6. Cleaning: Use compressed air to remove debris or sand from the surface of the substrate;

[0023] 7. Spray protection: The non-spray coating area should be protected with hard tooling or protective tape;

[0024] 8. Clamping: Use automated spray fixture to clamp the substrate;

[0025] 9. High velocity flame spraying NiCrAlYSi as the base layer;

[0026] 10. Supersonic flame spraying NiCoFeCrAl / Cr3C2.BaF2·CaF2 corrosion-resistant, wear-resistant and self-lubricating coating;

[0027] 11. Appearance inspection: The coating is uniform after spraying without overburning or discoloration.

[0028] in:

[0029] In step (9), the particle size of the NiCrAlYSi powder is between 25 μm and 55 μm, and the main components are, by mass percentage, Ni (60-70%), Cr (15-25%), Al (5-15%), Y (0.2-1.0%), and Si (0.2-1.0%). The powder particles are spherical.

[0030] In step (10), the mass ratio of NiCoFeCrAl to Cr3C2 in the NiCoFeCrAl / Cr3C2 powder is 1:3, the particle size is between 25 μm and 45 μm, and the main components are, by mass percentage, NiCoFeCrAl (14-28%), Cr (65-75%), and C (9-12%). The powder particles are spherical.

[0031] In the step (5), the surface of the substrate is roughened so that the surface roughness of the substrate reaches 2.0 to 2.5 μm.

[0032] In the step (9), the spraying fuels used for supersonic flame spraying of the NiCrAlYSi bottom layer are oxygen and kerosene, the oxygen flow rate is 800-900 L / min, and the kerosene flow rate is 15-25 L / h; the supersonic flame spraying distance is 320-400 mm, and the powder feeding rate is 25-45 g / min.

[0033] In the step (10), the spraying fuels used for supersonic flame spraying of the ceramic surface layer are oxygen and kerosene, the oxygen flow rate is 820-900 L / min, and the kerosene flow rate is 15-22 L / h; the supersonic flame spraying distance is 340-400 mm, and the powder feeding rate is 30-45 g / min.

[0034] In the steps (9) and (10), the thickness of the wear-resistant self-lubricating coating system obtained by spraying is 100 to 150 μm for the bonding layer and 100 to 230 μm for the surface layer.

[0035] The high temperature resistant, corrosion resistant and wear resistant self-lubricating coating system of the present invention can achieve a coating tensile bonding strength of more than 70MPa and a microhardness of HV 0.3Above 700℃, the number of heat shock resistance at 700℃ is more than 100 times, and it has excellent tribological properties: room temperature: friction coefficient is between 0.45 and 0.55; at 700℃, the friction coefficient is between 0.25 and 0.45. The oxidation rate after 650℃ oxidation test is 2.9mg / cm 2 .h, reaching complete antioxidant level.

[0036] Advantages of the present invention:

[0037] The present invention adopts a dual-layer structure system to improve the overall oxidation and corrosion resistance of the coating, ensure the compatibility between the coating and the substrate, and improve the thermal cycling performance of the coating, thereby reducing flaking during use. Specifically, NiCrAlYSi is supersonic sprayed on the surface of the metal substrate as a base layer to improve the compatibility between the coating and the metal substrate; and a high-entropy alloy / fluoride-containing chromium carbide (NiCoFeCrAl / Cr3C2.BaF2·CaF2) is supersonic flame sprayed as a corrosion-resistant, wear-resistant, self-lubricating top layer to improve the corrosion resistance of the wear-resistant coating system, ensuring that the coating system has both good friction and wear performance and satisfactory thermal cycling performance.

[0038] The present invention uses supersonic flame spraying technology to spray metal sublayers and ceramic wear-resistant coatings. Its high flame speed and low temperature can ensure a dense coating with better oxidation and corrosion resistance, tightly bonded to the metal substrate surface, and significantly improve the bonding strength between the coating, the metal substrate, and the coating. At the same time, supersonic flame spraying is particularly advantageous for spraying carbide ceramic coatings. The high particle velocity is conducive to obtaining high coating density and good bonding strength, while the low flame temperature can effectively inhibit or reduce the decomposition of hard phases such as carbides during the spraying process, so that the prepared coating maintains the original good wear resistance of the metal ceramic structure.

[0039] The invention performs dry sand blasting before spraying in order to clean, roughen and activate the surface of the runway matrix alloy so as to improve the bonding strength between the ceramic bottom layer and the alloy matrix.

[0040] The double-layer wear-resistant self-lubricating coating system of the present invention has high bonding strength and good resistance to heat cycle damage, meeting the use requirements of brush seals below 800°C, maximally extending the service life of brush wires and runways in high-speed friction and wear environments, and avoiding failures and scrapping caused by peeling of the runway surface coating or melting and deformation of the brush wires.

[0041] The dual-layer, wear-resistant, self-lubricating coating process of this invention can be used not only for the seal protection of brush seals in aircraft engines and gas turbines, but also for components such as disks and shafts that operate under high-temperature wear conditions. This coating technology and process can also be used for wear-resistant, self-lubricating protection of various hot-end components in aircraft engines and related industries. Its friction and wear performance can extend component life by 2 to 10 times. It can also be used in other power machinery fields, showing a very broad market prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 Microstructure of the cross section of supersonic sprayed NiCrAlYSi base layer + supersonic sprayed NiCoFeCrAl / Cr3C2.BaF2·CaF2 surface layer; DETAILED DESCRIPTION

[0043] In Example 1 of the present invention, a supersonic spraying process is used to prepare and spray NiCrAlYSi as a corrosion-resistant and wear-resistant coating bottom layer to improve the matching between the coating and the metal substrate and the corrosion resistance; a supersonic flame spraying NiCoFeCrAl / Cr3C2.BaF2·CaF2 is used as a corrosion-resistant and wear-resistant coating surface layer; the microstructure of the cross section of the supersonic spraying NiCrAlYSi bottom layer + supersonic spraying NiCoFeCrAl / Cr3C2.BaF2·CaF2 surface layer is as follows: Figure 1 shown.

[0044] Example 1

[0045] A process for preparing a corrosion-resistant, wear-resistant, self-lubricating coating, the specific steps are as follows:

[0046] (1) Preparation of corrosion-resistant, wear-resistant and self-lubricating coating structural system materials:

[0047] Double-layer corrosion-resistant, wear-resistant, self-lubricating coating. NiCrAlYSi powder particle size ranges from 25μm to 55μm. The main components, by mass percentage, are: Ni (60-70%), Cr (15-25%), Al (5-15%), Y (0.2-1.0%), and Si (0.2-1.0%). The powder particles are spherical.

[0048] The mass ratio of NiCoFeCrAl to Cr3C2 in the NiCoFeCrAl / Cr3C2.BaF2·CaF2 powder is 1:3, and the particle size ranges from 25μm to 45μm. The main components, by mass percentage, are: NiCoFeCrAl (13-26%), Cr (65-75%), and C (9-12%). The powder particles are spherical.

[0049] (2) Preparation of corrosion-resistant and wear-resistant self-lubricating coating, the process flow is as follows:

[0050] 1. Incoming inspection: Check whether there are defects such as pores and cracks on the surface of the substrate;

[0051] 2. Use acetone to remove oil stains;

[0052] 3. Appearance inspection: Visually inspect the surface of the substrate to see if there is any oil stain on the sprayed surface;

[0053] 4. Sandblasting protection: The non-spray coating area is protected with metal and rubber tooling or protective tape;

[0054] 5. Dry sand blowing: Alumina sand is used to roughen the surface of the substrate, and the surface roughness of the substrate reaches 2.0-2.5μm;

[0055] 6. Cleaning: Use compressed air to remove debris or sand from the surface of the substrate;

[0056] 7. Spray protection: The non-spray coating area should be protected with hard tooling or protective tape;

[0057] 8. Clamping: Use automated spray fixture to clamp the substrate;

[0058] 9. Supersonic flame spraying of NiCrAlYSi as the base layer of the corrosion-resistant and wear-resistant coating: using supersonic flame spraying equipment with oxygen and kerosene as fuel, the spraying distance is 350mm, the powder feeding rate is 35g / min, the oxygen flow rate is 850L / min, and the kerosene flow rate is 16L / h.

[0059] 10. Supersonic flame spraying of NiCoFeCrAl / Cr3C2.BaF2·CaF2 as a corrosion-resistant, wear-resistant, self-lubricating composite coating surface layer: Using supersonic flame spraying equipment using oxygen and kerosene as fuel, the spraying distance is 350 mm, the powder feed rate is 30 g / min, the oxygen flow rate is 850 L / min, and the kerosene flow rate is 16 L / h.

[0060] 11. Appearance inspection: The coating is uniform after spraying without overburning or discoloration.

[0061] The NiCrAlYSi bonding layer of the sprayed corrosion-resistant, wear-resistant, self-lubricating coating system has a thickness of approximately 80 μm, while the surface ceramic structure has a thickness of 150 μm. Test results for the corrosion-resistant, wear-resistant, self-lubricating coating's bond strength averaged 72 MPa, with fracture primarily occurring near the base / surface interface. The microhardness reached 713 HV0.3. Thermal shock testing of the coating was conducted at 700°C using forced air cooling. After 100 thermal shock tests, the coating surface showed no signs of flaking, and the coating interface showed no cracking. The friction coefficient at 700°C was between 0.28 and 0.35.

[0062] Example 2

[0063] A process for preparing a corrosion-resistant, wear-resistant, self-lubricating coating, the specific steps are as follows:

[0064] (1) Preparation of corrosion-resistant, wear-resistant and self-lubricating coating structural system materials:

[0065] The NiCrAlYSi powder has a particle size of 25μm to 55μm, and its main components, by mass percentage, are: Ni (60-70%), Cr (15-25%), Al (5-15%), Y (0.2-1.0%), and Si (0.2-1.0%). The powder particles are spherical.

[0066] The mass ratio of NiCoFeCrAl to Cr3C2 in the NiCoFeCrAl / Cr3C2.BaF2·CaF2 powder is 1:3, and the particle size ranges from 25μm to 45μm. The main components, by mass percentage, are: NiCoFeCrAl (13-26%), Cr (65-75%), and C (9-12%). The powder particles are spherical.

[0067] (2) Preparation of wear-resistant self-lubricating coating, the process flow is as follows:

[0068] 1. Incoming inspection: Check whether there are defects such as pores and cracks on the surface of the substrate;

[0069] 2. Use acetone to remove oil stains;

[0070] 3. Appearance inspection: Visually inspect the surface of the substrate to see if there is any oil stain on the sprayed surface;

[0071] 4. Sandblasting protection: The non-spray coating area is protected with metal and rubber tooling or protective tape;

[0072] 5. Dry sand blowing: Alumina sand is used to roughen the surface of the substrate, and the surface roughness of the substrate reaches 2.0-2.5μm;

[0073] 6. Cleaning: Use compressed air to remove debris or sand from the surface of the substrate;

[0074] 7. Spray protection: The non-spray coating area should be protected with hard tooling or protective tape;

[0075] 8. Clamping: Use automated spray fixture to clamp the substrate;

[0076] 9. Supersonic flame spraying of NiCrAlYSi as the base layer of the corrosion-resistant and wear-resistant coating: using supersonic flame spraying equipment with oxygen and kerosene as fuel, the spraying distance is 350mm, the powder feeding rate is 35g / min, the oxygen flow rate is 900L / min, and the kerosene flow rate is 20L / h.

[0077] 10. Supersonic flame spraying of NiCoFeCrAl / Cr3C2.BaF2·CaF2 as a corrosion-resistant, wear-resistant, self-lubricating composite coating surface: Using supersonic flame spraying equipment using oxygen and kerosene as fuel, the spraying distance is 350 mm, the powder feed rate is 30 g / min, the oxygen flow rate is 900 L / min, and the kerosene flow rate is 20 L / h.

[0078] 11. Appearance inspection: The coating is uniform after spraying without overburning or discoloration.

[0079] The NiCrAlYSi bond layer of the sprayed wear-resistant, self-lubricating coating system has a thickness of approximately 100 μm, and the surface ceramic coating is 180 μm thick. Test results for the wear-resistant, self-lubricating coating's bond strength averaged 73 MPa, with fracture primarily occurring near the base / surface interface. The microhardness reached 732 HV0.3. Thermal shock testing was conducted using forced air cooling at 700°C. After 100 thermal shock cycles, the coating showed no flaking or cracking at the coating interface. The coefficient of friction at 700°C was between 0.25 and 0.38.

[0080] Example 3

[0081] A process for preparing a corrosion-resistant, wear-resistant, self-lubricating coating, the specific steps are as follows:

[0082] (1) Preparation of wear-resistant self-lubricating coating structural system materials:

[0083] The NiCrAlYSi powder has a particle size of 25μm to 55μm, and its main components, by mass percentage, are: Ni (60-70%), Cr (15-25%), Al (5-15%), Y (0.2-1.0%), and Si (0.2-1.0%). The powder particles are spherical.

[0084] The mass ratio of NiCoFeCrAl to Cr3C2 in the NiCoFeCrAl / Cr3C2.BaF2·CaF2 powder is 1:3, and the particle size ranges from 25μm to 45μm. The main components, by mass percentage, are: NiCoFeCrAl (13-26%), Cr (65-75%), and C (9-12%). The powder particles are spherical.

[0085] (2) Preparation of corrosion-resistant and wear-resistant self-lubricating coating, the process flow is as follows:

[0086] 1. Incoming inspection: Check whether there are defects such as pores and cracks on the surface of the substrate;

[0087] 2. Use acetone to remove oil stains;

[0088] 3. Appearance inspection: Visually inspect the surface of the substrate to see if there is any oil stain on the sprayed surface;

[0089] 4. Sandblasting protection: The non-spray coating area is protected with metal and rubber tooling or protective tape;

[0090] 5. Dry sand blowing: Alumina sand is used to roughen the surface of the substrate, and the surface roughness of the substrate reaches 2.0-2.5μm;

[0091] 6. Cleaning: Use compressed air to remove debris or sand from the surface of the substrate;

[0092] 7. Spray protection: The non-spray coating area should be protected with hard tooling or protective tape;

[0093] 8. Clamping: Use automated spray fixture to clamp the substrate;

[0094] 9. Supersonic flame spraying of NiCrAlYSi as the base layer of the corrosion-resistant and wear-resistant coating: using supersonic flame spraying equipment with oxygen and kerosene as fuel, the spraying distance is 350mm, the powder feeding rate is 40g / min, the oxygen flow rate is 880L / min, and the kerosene flow rate is 20L / h.

[0095] 10. Supersonic flame spraying of NiCoFeCrAl / Cr3C2.BaF2·CaF2 as a wear-resistant, self-lubricating composite coating surface: Using supersonic flame spraying equipment using oxygen and kerosene as fuel, the spraying distance is 350 mm, the powder feed rate is 35 g / min, the oxygen flow rate is 880 L / min, and the kerosene flow rate is 20 L / h.

[0096] 11. Appearance inspection: The coating is uniform after spraying without overburning or discoloration.

[0097] The NiCrAlYSi bonding layer of the sprayed corrosion-resistant, wear-resistant, self-lubricating coating system has a thickness of approximately 150 μm, and the surface ceramic structure has a thickness of 200 μm. The average bond strength test result of the corrosion-resistant, wear-resistant, self-lubricating coating is 70 MPa, with fracture primarily occurring near the bonding base / surface interface. The microhardness reaches 716 HV0.3. Thermal shock tests were conducted using forced air cooling at a temperature of 700°C. After 100 thermal shock tests, there was no flaking on the coating surface and no cracking at the coating interface. The friction coefficient at 700°C was between 0.24 and 0.39.

[0098] Matters not covered by the present invention are known technologies.

[0099] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A process for preparing a corrosion-resistant, wear-resistant, self-lubricating coating for an aircraft engine, characterized by: The preparation process of the corrosion-resistant, wear-resistant and self-lubricating coating for aircraft engines adopts a double-layer structural system, that is, NiCrAlYSi is supersonic sprayed on the surface of the metal substrate as the corrosion-resistant and wear-resistant coating bottom layer, and high-entropy alloy / fluoride-containing chromium carbide (NiCoFeCrAl / Cr3C2.BaF2.CaF2) is supersonic flame sprayed as the wear-resistant and self-lubricating surface layer; The specific technical solutions are as follows: (1) Preparation of wear-resistant self-lubricating coating structural system materials Ceramic base material: The present invention adopts NiCrAlYSi powder prepared by vacuum atomization method to enhance the bonding strength between the coating and the substrate and the coating, and improve the matching between the coating and the metal substrate and the coating; Surface layer material: The present invention adopts a high entropy alloy / fluoride-containing chromium carbide (NiCoFeCrAl / Cr3C2.BaF2·CaF2) surface layer to improve the corrosion resistance of the wear-resistant self-lubricating coating; (2) Design of wear-resistant self-lubricating coating structure system When the coating is prepared using a thermal spraying process, the thermal stress within the coating increases as the thickness increases. At the same time, the engine's alternating hot and cold environment also generates large residual thermal stress within the coating, which, coupled with the high-speed friction of the brush wire, adversely affects the coating's ability to resist spalling. To improve the thermal shock life of the wear-resistant self-lubricating coating, a double-layer corrosion-resistant, wear-resistant, self-lubricating coating is used. Supersonic spraying of NiCrAlYSi is used as the corrosion-resistant, wear-resistant coating base layer to improve the coating system's compatibility, as well as its corrosion and oxidation resistance. Supersonic flame spraying of NiCoFeCrAl / Cr3C2.BaF2·CaF2 is used as the wear-resistant, self-lubricating surface layer. The patented double-layer corrosion-resistant, wear-resistant, self-lubricating coating has a uniform coating structure, good wear-resistant, lubricating, and corrosion-resistant properties, as well as excellent bonding strength and spalling resistance. (3) Coating preparation process Supersonic flame spraying is a high-velocity flame spraying technology characterized by high flame speed and low temperature. Supersonic flame spraying is particularly beneficial for spraying metal coatings and carbide ceramic coatings. The high particle velocity is conducive to obtaining high coating density and good bonding strength, thereby improving high-temperature oxidation resistance and corrosion resistance. The low flame temperature can effectively inhibit or reduce the decomposition and ablation of hard phases such as carbides and lubricating phases such as fluorides during the spraying process, so that the prepared coating maintains the original good wear resistance of carbide ceramics and the original lubricity of fluorides.

2. The process for preparing the corrosion-resistant and wear-resistant self-lubricating coating for aircraft engines according to claim 1, characterized in that: In the coating preparation process (3), the process flow is as follows: (1) Inspection of incoming parts: Check whether there are defects such as pores and cracks on the surface of the substrate; (2) Acetone degreasing; (3) Appearance inspection: Visually inspect the substrate surface for oil stains; (4) Sandblasting protection: The non-spray coating area is protected with metal and rubber tooling or protective tape; (5) Dry sand blowing: Alumina sand is used to roughen the substrate surface to a surface roughness of 2.0 to 2.5 μm. (6) Cleaning: Use compressed air to remove debris or sand from the surface of the substrate; (7) Spray protection: The non-spray coating area should be protected with hard tooling or protective tape; (8) Clamping: Use automated spray fixtures to clamp the substrate; (9) High velocity flame spraying NiCrAlYSi as the bottom layer; (10) High velocity flame spraying NiCoFeCrAl / Cr3C2.BaF2·CaF2 corrosion resistant and wear resistant self-lubricating coating; (11) Appearance inspection: The coating is uniform after spraying without any over-burning or discoloration.

3. The process for preparing the corrosion-resistant and wear-resistant self-lubricating coating for aircraft engines according to claim 2, characterized in that: In the step (9), the particle size of the NiCrAlYSi powder is between 25 μm and 55 μm, and the main components are calculated by mass percentage: Ni (60-70%), Cr (15-25%), Al (5-15%), Y (0.2-1.0%), and Si (0.2-1.0%); the powder particles are spherical.

4. The process for preparing the corrosion-resistant and wear-resistant self-lubricating coating for aircraft engines according to claim 2, characterized in that: In the step (10), the mass ratio of NiCoFeCrAl to Cr3C2 in the NiCoFeCrAl / Cr3C2 powder is 1:3, the particle size is between 25μm and 45μm, and the main components are calculated by mass percentage: NiCoFeCrAl (14-28%), Cr (65-75%), and C (9-12%); the powder particles are spherical.

5. The process for preparing the corrosion-resistant and wear-resistant self-lubricating coating for aircraft engines according to claim 2, characterized in that: In the step (5), the surface of the substrate is roughened so that the surface roughness of the substrate reaches 2.0 to 2.5 μm.

6. The process for preparing the corrosion-resistant and wear-resistant self-lubricating coating for aircraft engines according to claim 2, characterized in that: In the step (9), the spraying fuels used for supersonic flame spraying of the NiCrAlYSi bottom layer are oxygen and kerosene, the oxygen flow rate is 800-900 L / min, and the kerosene flow rate is 15-25 L / h; the supersonic flame spraying distance is 320-400 mm, and the powder feeding rate is 25-45 g / min.

7. The process for preparing the corrosion-resistant and wear-resistant self-lubricating coating for aircraft engines according to claim 2, characterized in that: In the step (10), the spraying fuels used for supersonic flame spraying of the ceramic surface layer are oxygen and kerosene, the oxygen flow rate is 820-900 L / min, and the kerosene flow rate is 15-22 L / h; the supersonic flame spraying distance is 340-400 mm, and the powder feeding rate is 30-45 g / min.

8. The process for preparing the corrosion-resistant, wear-resistant, self-lubricating coating for aircraft engines according to claim 2, characterized in that: In the steps (9) and (10), the thickness of the wear-resistant self-lubricating coating system obtained by spraying is 100 to 150 μm for the bonding layer and 100 to 230 μm for the surface layer.

Images