An oxidation-resistant low-abrasion heat-resistant steam turbine blade coating and a preparation method thereof

Abstract

The application provides an antioxidant low-abrasion heat-resistant steam turbine blade coating and a preparation method thereof, and relates to the technical field of material surface treatment, and comprises the following components in mass ratio: nickel-cobalt-chromium-aluminum-yttrium alloy 20-30 parts, zirconia-yttria-alumina composite ceramic 30-40 parts, hafnium powder and rhenium powder mixture 10-15 parts, chromium sesquioxide 5-10 parts, rare earth oxide 3-5 parts, cerium dioxide 2-4 parts, silicon dioxide 3-5 parts, titanium carbide 5-8 parts, and zirconium boride 2-4 parts; the nickel-cobalt-chromium-aluminum-yttrium alloy and the zirconia-yttria-alumina composite ceramic are used in the application, a stable oxide film can be formed at high temperature, the further diffusion of oxygen is effectively prevented, the rare earth oxide and the cerium dioxide can promote the repair and stability of the oxide film, the antioxidant capacity of the coating is improved, and the blade can maintain good performance in a high-temperature environment for a long time.

Description

Technical Field

[0001] This invention relates to the field of material surface treatment technology, and in particular to an antioxidant, low-wear, and heat-resistant steam turbine blade coating and its preparation method. Background Technology

[0002] As a key device for energy conversion and power output, steam turbine blades operate for extended periods in environments with high temperature, high pressure, high speed, and corrosive media. They face multiple damage risks, including oxidation, wear, and thermal fatigue. Oxidation leads to the formation of oxide scale on the blade surface, reducing its mechanical properties. Wear reduces the dimensional accuracy of the blades, affecting the operating efficiency of the steam turbine. Thermal fatigue can cause blade cracks or even fractures, seriously threatening the safe operation of the steam turbine. Therefore, the role of blade coating is crucial.

[0003] In existing technologies, traditional coatings include nickel-based alloys (NiCrAlY) and ceramic coatings (YSZ), which mainly have the following problems: Nickel-based coatings: high oxidation rate at high temperatures (weight gain reaches 4.0 mg / cm³ after 100 hours of oxidation at 1000℃). 2 Furthermore, the existing materials are prone to cracking due to insufficient toughness; ceramic coatings have a large difference in thermal expansion coefficient with the substrate, and are prone to peeling after 50 thermal shock cycles; composite coatings, such as NiCrAlY / YSZ / TiC coatings, have high wear rates and insufficient oxidation resistance. Therefore, this invention proposes an oxidation-resistant, low-wear, and heat-resistant steam turbine blade coating and its preparation method to solve the problems existing in the prior art. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes an antioxidant, low-wear, and heat-resistant steam turbine blade coating and its preparation method. This antioxidant, low-wear, and heat-resistant steam turbine blade coating has strong antioxidant capabilities, enabling the blade to maintain good performance over a long period of time in high-temperature environments.

[0005] To achieve the objectives of this invention, the following technical solution is provided: an anti-oxidation, low-wear, and heat-resistant steam turbine blade coating, comprising the following components in the indicated mass ratio: 20-30 parts of nickel-cobalt-chromium-aluminum-yttrium alloy (Ni-Co-Cr-Al-Y), 30-40 parts of zirconium oxide-yttrium oxide-alumina composite ceramic (ZrO2-Y2O3-Al2O3), 10-15 parts of a mixture of hafnium powder and rhenium powder (Hf:Re), 5-10 parts of chromium trioxide (Cr2O3), 3-5 parts of rare earth oxides, 2-4 parts of cerium dioxide (CeO2), 3-5 parts of silicon dioxide (SiO2), 5-8 parts of titanium carbide (TiC), and 2-4 parts of zirconium boride (ZrB2).

[0006] Further improvements include the following mass ratio composition: 25 parts of nickel-cobalt-chromium-aluminum-yttrium alloy (Ni-Co-Cr-Al-Y), 35 parts of zirconium oxide-yttrium oxide-alumina composite ceramic (ZrO2-Y2O3-Al2O3), 12 parts of hafnium powder and rhenium powder mixture (Hf:Re), 8 parts of chromium trioxide (Cr2O3), 4 parts of rare earth oxides, 3 parts of cerium dioxide (CeO2), 4 parts of silicon dioxide (SiO2), 6 parts of titanium carbide (TiC), and 3 parts of zirconium boride (ZrB2).

[0007] A further improvement is that the Al content in the nickel-cobalt-chromium-aluminum-yttrium alloy is 8-10%, and the Y content is 0.5-1.5%.

[0008] A further improvement is that the mass ratio of hafnium powder to rhenium powder in the hafnium powder and rhenium powder mixture is 1:1.

[0009] A further improvement is that in the zirconium oxide-yttrium oxide-alumina composite ceramic, the mass percentages of ZrO2, Y2O3, and Al2O3 are 87%:8%:5%, and the rare earth oxides are a mixture of La2O3 and Nd2O3 in a mass ratio of 2:1.

[0010] A method for preparing an antioxidant, low-wear, and heat-resistant coating for steam turbine blades includes the following steps:

[0011] S1: The raw materials are micronized and dried, and then put into a mixer for thorough mixing;

[0012] S2: Add organic solvent and binder to the mixed powder, stir evenly, and obtain coating slurry;

[0013] S3: The coating slurry is uniformly coated onto the surface of the turbine blades using plasma spraying.

[0014] S4: After coating, heat-treat the blades to secure the coating.

[0015] Further improvements are made in the following aspects: In step S1, the nickel-cobalt-chromium-aluminum-yttrium alloy, hafnium powder, and rhenium powder are ground separately to achieve a particle size of micron; the zirconium oxide-yttrium oxide-alumina composite ceramic, chromium trioxide, rare earth oxides, cerium dioxide, silicon dioxide, titanium carbide, and zirconium boride are dried to remove moisture. When fully mixed in the mixer, the mixing time is controlled to be 6-8 hours to ensure uniform distribution of each raw material.

[0016] A further improvement is made in S2, where an organic solvent and a binder are added to the mixed powder, the mass ratio of the organic solvent to the powder is controlled to be 2:1, the amount of binder added is 4%-6% of the powder mass, and the mixture is stirred evenly to form a coating slurry with viscosity and fluidity.

[0017] Further improvements are made in S3, where the spraying power is controlled at 30-40kW, the spraying distance at 100-120mm, and the powder feeding rate at 5-8g / min during spraying to ensure uniform coating thickness.

[0018] A further improvement is that S4 includes the following steps:

[0019] First, the blades are subjected to vacuum hot pressing sintering, and the temperature is maintained at 900-1100℃ for 2-3 hours, with the pressure controlled at 20MPa.

[0020] Next, laser cladding is performed, with the wavelength controlled at 1064nm, power at 3-4kW, and spot diameter at 3mm.

[0021] After completion, cool to room temperature to improve the density of the coating and its adhesion to the blade substrate.

[0022] The beneficial effects of this invention are as follows:

[0023] 1. This invention uses nickel-cobalt-chromium-aluminum-yttrium alloy and zirconium oxide-yttrium oxide-alumina composite ceramic, which can form a stable oxide film at high temperature, effectively preventing further diffusion of oxygen. Rare earth oxides and cerium dioxide can promote the repair and stabilization of the oxide film, improve the oxidation resistance of the coating, and enable the blade to maintain good performance for a long time in high temperature environment.

[0024] 2. This invention uses a mixture of titanium carbide, hafnium powder, and rhenium powder, which has the characteristics of high hardness and high strength, and can enhance the wear resistance of the coating. Chromium trioxide can further improve the hardness and wear resistance of the coating, reduce the wear of the blades during operation, and extend the service life of the blades.

[0025] 3. This invention uses zirconium boride and silicon dioxide, which have excellent high temperature resistance and thermal stability, and can improve the coating's resistance to thermal shock, preventing the coating from cracking and peeling at high temperatures. At the same time, the composite ceramic material can also enhance the coating's heat resistance, enabling the coating to withstand the high temperature environment during turbine operation.

[0026] 4. This invention, through plasma spraying and subsequent heat treatment, enables the coating to form a good bond with the blade substrate, improving the coating's adhesion and anti-peeling ability, ensuring that the coating will not peel off during long-term use, effectively protecting the turbine blades, and improving the turbine's operating efficiency and reliability. Attached Figure Description

[0027] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0028] To enhance understanding of the present invention, the present invention will be further described in detail below with reference to embodiments. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0029] Example 1

[0030] according to Figure 1 As shown, this embodiment proposes an anti-oxidation, low-wear, and heat-resistant steam turbine blade coating, comprising the following components by mass ratio: 20 parts of nickel-cobalt-chromium-aluminum-yttrium alloy (Ni-Co-Cr-Al-Y), 30 parts of zirconium oxide-yttrium oxide-alumina composite ceramic (ZrO2-Y2O3-Al2O3), 10 parts of a mixture of hafnium powder and rhenium powder (Hf:Re), 5 parts of chromium trioxide (Cr2O3), 3 parts of rare earth oxides, 2 parts of cerium dioxide (CeO2), 3 parts of silicon dioxide (SiO2), 5 parts of titanium carbide (TiC), and 2 parts of zirconium boride (ZrB2).

[0031] Nickel-cobalt-chromium-aluminum-yttrium alloy is used as a bonding layer to improve adhesion and initial oxidation resistance.

[0032] A mixture of hafnium powder and rhenium powder, chromium trioxide and rare earth oxides are used as an anti-diffusion layer to suppress interdiffusion of elements and delay coating degradation.

[0033] Zirconia-yttrium oxide-alumina composite ceramics are used as the energy supply layer, which is resistant to high temperature and low wear.

[0034] Cerium dioxide and silicon dioxide are used as surface modification layers for nano-sealing to enhance antioxidant properties.

[0035] The nickel-cobalt-chromium-aluminum-yttrium alloy contains 8-10% Al and 0.5-1.5% Y. The hafnium powder to rhenium powder mixture has a mass ratio of 1:1. In the zirconium oxide-yttrium oxide-alumina composite ceramic, the mass percentages of ZrO2, Y2O3, and Al2O3 are 87%:8%:5%, and the rare earth oxides are a mixture of La2O3 and Nd2O3 with a mass ratio of 2:1.

[0036] A method for preparing an antioxidant, low-wear, and heat-resistant coating for steam turbine blades includes the following steps:

[0037] The raw materials are micronized and dried before being thoroughly mixed in a mixer. The nickel-cobalt-chromium-aluminum-yttrium alloy, hafnium powder, and rhenium powder are ground separately to achieve a particle size of micron. The zirconium oxide-yttrium oxide-alumina composite ceramic, chromium trioxide, rare earth oxides, cerium dioxide, silicon dioxide, titanium carbide, and zirconium boride are dried to remove moisture. When thoroughly mixed in the mixer, the mixing time is controlled to be 6-8 hours to ensure uniform distribution of the raw materials.

[0038] Organic solvent and binder are added to the mixed powder and stirred evenly to obtain a coating slurry; the mass ratio of organic solvent to powder is controlled at 2:1, and the amount of binder added is 4%-6% of the powder mass. Stir evenly to prepare a coating slurry with viscosity and fluidity.

[0039] Plasma spraying is used to uniformly coat the surface of the turbine blades with a coating slurry. During spraying, the spraying power is controlled at 30-40kW, the spraying distance is 100-120mm, and the powder feeding rate is 5-8g / min to ensure that the coating thickness is uniform.

[0040] After coating, the blade undergoes heat treatment to solidify the coating. This includes the following steps: first, the blade is vacuum hot-pressed and sintered at 900-1100℃ for 2-3 hours, with a controlled pressure of 20MPa; then, laser cladding is performed, controlling the wavelength at 1064nm, the power at 3-4kW, and the spot diameter at 3mm; finally, it is cooled to room temperature to improve the density of the coating and its adhesion to the blade substrate.

[0041] Example 2

[0042] according to Figure 1 As shown, this embodiment proposes an anti-oxidation, low-wear, and heat-resistant steam turbine blade coating, comprising the following components by mass ratio: 25 parts of nickel-cobalt-chromium-aluminum-yttrium alloy (Ni-Co-Cr-Al-Y), 35 parts of zirconium oxide-yttrium oxide-alumina composite ceramic (ZrO2-Y2O3-Al2O3), 12 parts of a mixture of hafnium powder and rhenium powder (Hf:Re), 8 parts of chromium trioxide (Cr2O3), 4 parts of rare earth oxides, 3 parts of cerium dioxide (CeO2), 4 parts of silicon dioxide (SiO2), 6 parts of titanium carbide (TiC), and 3 parts of zirconium boride (ZrB2).

[0043] Nickel-cobalt-chromium-aluminum-yttrium alloy is used as a bonding layer to improve adhesion and initial oxidation resistance.

[0044] A mixture of hafnium powder and rhenium powder, chromium trioxide and rare earth oxides are used as an anti-diffusion layer to suppress interdiffusion of elements and delay coating degradation.

[0045] Zirconia-yttrium oxide-alumina composite ceramics are used as the energy supply layer, which is resistant to high temperature and low wear.

[0046] Cerium dioxide and silicon dioxide are used as surface modification layers for nano-sealing to enhance antioxidant properties.

[0047] The nickel-cobalt-chromium-aluminum-yttrium alloy contains 8-10% Al and 0.5-1.5% Y. The hafnium powder to rhenium powder mixture has a mass ratio of 1:1. In the zirconium oxide-yttrium oxide-alumina composite ceramic, the mass percentages of ZrO2, Y2O3, and Al2O3 are 87%:8%:5%, and the rare earth oxides are a mixture of La2O3 and Nd2O3 with a mass ratio of 2:1.

[0048] A method for preparing an antioxidant, low-wear, and heat-resistant coating for steam turbine blades includes the following steps:

[0049] The raw materials are micronized and dried before being thoroughly mixed in a mixer. The nickel-cobalt-chromium-aluminum-yttrium alloy, hafnium powder, and rhenium powder are ground separately to achieve a particle size of micron. The zirconium oxide-yttrium oxide-alumina composite ceramic, chromium trioxide, rare earth oxides, cerium dioxide, silicon dioxide, titanium carbide, and zirconium boride are dried to remove moisture. When thoroughly mixed in the mixer, the mixing time is controlled to be 6-8 hours to ensure uniform distribution of the raw materials.

[0050] Organic solvent and binder are added to the mixed powder and stirred evenly to obtain a coating slurry; the mass ratio of organic solvent to powder is controlled at 2:1, and the amount of binder added is 4%-6% of the powder mass. Stir evenly to prepare a coating slurry with viscosity and fluidity.

[0051] Plasma spraying is used to uniformly coat the surface of the turbine blades with a coating slurry. During spraying, the spraying power is controlled at 30-40kW, the spraying distance is 100-120mm, and the powder feeding rate is 5-8g / min to ensure that the coating thickness is uniform.

[0052] After coating, the blade undergoes heat treatment to solidify the coating. This includes the following steps: first, the blade is vacuum hot-pressed and sintered at 900-1100℃ for 2-3 hours, with a controlled pressure of 20MPa; then, laser cladding is performed, controlling the wavelength at 1064nm, the power at 3-4kW, and the spot diameter at 3mm; finally, it is cooled to room temperature to improve the density of the coating and its adhesion to the blade substrate.

[0053] Example 3

[0054] according to Figure 1As shown, this embodiment proposes an anti-oxidation, low-wear, and heat-resistant steam turbine blade coating, comprising the following components by mass ratio: 30 parts of nickel-cobalt-chromium-aluminum-yttrium alloy (Ni-Co-Cr-Al-Y), 40 parts of zirconium oxide-yttrium oxide-alumina composite ceramic (ZrO2-Y2O3-Al2O3), 15 parts of a mixture of hafnium powder and rhenium powder (Hf:Re), 10 parts of chromium trioxide (Cr2O3), 5 parts of rare earth oxides, 4 parts of cerium dioxide (CeO2), 5 parts of silicon dioxide (SiO2), 8 parts of titanium carbide (TiC), and 4 parts of zirconium boride (ZrB2).

[0055] Nickel-cobalt-chromium-aluminum-yttrium alloy is used as a bonding layer to improve adhesion and initial oxidation resistance.

[0056] A mixture of hafnium powder and rhenium powder, chromium trioxide and rare earth oxides are used as an anti-diffusion layer to suppress interdiffusion of elements and delay coating degradation.

[0057] Zirconia-yttrium oxide-alumina composite ceramics are used as the energy supply layer, which is resistant to high temperature and low wear.

[0058] Cerium dioxide and silicon dioxide are used as surface modification layers for nano-sealing to enhance antioxidant properties.

[0059] The nickel-cobalt-chromium-aluminum-yttrium alloy contains 8-10% Al and 0.5-1.5% Y. The hafnium powder to rhenium powder mixture has a mass ratio of 1:1. In the zirconium oxide-yttrium oxide-alumina composite ceramic, the mass percentages of ZrO2, Y2O3, and Al2O3 are 87%:8%:5%, and the rare earth oxides are a mixture of La2O3 and Nd2O3 with a mass ratio of 2:1.

[0060] A method for preparing an antioxidant, low-wear, and heat-resistant coating for steam turbine blades includes the following steps:

[0061] The raw materials are micronized and dried before being thoroughly mixed in a mixer. The nickel-cobalt-chromium-aluminum-yttrium alloy, hafnium powder, and rhenium powder are ground separately to achieve a particle size of micron. The zirconium oxide-yttrium oxide-alumina composite ceramic, chromium trioxide, rare earth oxides, cerium dioxide, silicon dioxide, titanium carbide, and zirconium boride are dried to remove moisture. When thoroughly mixed in the mixer, the mixing time is controlled to be 6-8 hours to ensure uniform distribution of the raw materials.

[0062] Organic solvent and binder are added to the mixed powder and stirred evenly to obtain a coating slurry; the mass ratio of organic solvent to powder is controlled at 2:1, and the amount of binder added is 4%-6% of the powder mass. Stir evenly to prepare a coating slurry with viscosity and fluidity.

[0063] Plasma spraying is used to uniformly coat the surface of the turbine blades with a coating slurry. During spraying, the spraying power is controlled at 30-40kW, the spraying distance is 100-120mm, and the powder feeding rate is 5-8g / min to ensure that the coating thickness is uniform.

[0064] After coating, the blade undergoes heat treatment to solidify the coating. This includes the following steps: first, the blade is vacuum hot-pressed and sintered at 900-1100℃ for 2-3 hours, with a controlled pressure of 20MPa; then, laser cladding is performed, controlling the wavelength at 1064nm, the power at 3-4kW, and the spot diameter at 3mm; finally, it is cooled to room temperature to improve the density of the coating and its adhesion to the blade substrate.

[0065] Based on Examples 1, 2, and 3, it can be concluded that the coating prepared by the present invention is composed of the following mass ratio: 20-30 parts of nickel-cobalt-chromium-aluminum-yttrium alloy (Ni-Co-Cr-Al-Y), 30-40 parts of zirconium oxide-yttrium oxide-alumina composite ceramic (ZrO2-Y2O3-Al2O3), 10-15 parts of hafnium powder and rhenium powder mixture (Hf:Re), 5-10 parts of chromium trioxide (Cr2O3), 3-5 parts of rare earth oxides, 2-4 parts of cerium dioxide (CeO2), 3-5 parts of silicon dioxide (SiO2), 5-8 parts of titanium carbide (TiC), and 2-4 parts of zirconium boride (ZrB2).

[0066] By rationally combining various materials such as nickel-cobalt-chromium-aluminum-yttrium alloy, zirconium oxide-yttrium oxide-alumina composite ceramics, hafnium powder and rhenium powder mixture, chromium trioxide, rare earth oxides, cerium dioxide, silicon dioxide, titanium carbide, and zirconium boride, the advantages of each material are fully utilized, achieving a synergistic improvement in the coating's anti-oxidation, wear resistance, and heat resistance. Compared with existing coating formulations, it exhibits superior overall performance. A series of process steps, including raw material pretreatment, mixing and formulation, coating slurry preparation, plasma spraying, and post-treatment, are employed, with precise control of parameters at each step to ensure the coating's quality and performance. In particular, plasma spraying enables the coating to form a good bond with the blade substrate, while heat treatment improves the coating's density and adhesion. Experimental data show that the coating of this invention significantly outperforms uncoated blades in terms of anti-oxidation, wear resistance, and heat resistance, effectively solving the problems existing in current turbine blade coatings and providing a new and effective solution for turbine blade protection.

[0067] Verification example:

[0068]

[0069] This invention employs a nickel-cobalt-chromium-aluminum-yttrium alloy and a zirconium oxide-yttrium oxide-alumina composite ceramic, which can form a stable oxide film at high temperatures, effectively preventing further oxygen diffusion. Rare earth oxides and cerium dioxide can promote the repair and stabilization of the oxide film, improve the coating's oxidation resistance, and enable the blades to maintain good performance for a long time under high-temperature environments. Furthermore, this invention uses a mixture of titanium carbide and hafnium powder and rhenium powder, which has high hardness and high strength, enhancing the coating's wear resistance. Chromium trioxide can further improve the coating's hardness and wear resistance, reducing blade wear during operation and extending the blade's service life. Simultaneously, this invention uses zirconium boride and silicon dioxide, which have excellent high-temperature resistance and thermal stability, improving the coating's resistance to thermal shock and preventing cracking and peeling at high temperatures. The composite ceramic material also enhances the coating's heat resistance, enabling it to withstand the high-temperature environment during turbine operation. In addition, the present invention, through plasma spraying and subsequent heat treatment, enables the coating to form a good bond with the blade substrate, improves the coating's adhesion and anti-peeling ability, ensures that the coating will not fall off during long-term use, effectively protects the turbine blades, and improves the turbine's operating efficiency and reliability.

[0070] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. An oxidation resistant, low wear, heat resistant gas turbine vane coating characterized by, The alloy Ni-Co-Cr-Al-Y contains 20-30 parts of nickel-cobalt-chromium-aluminum-yttrium, the composite ceramic ZrO2-Y2O3-Al2O3 contains 30-40 parts of zirconium oxide-yttrium oxide-aluminum oxide, the mixture Hf:Re contains 10-15 parts of hafnium powder and rhenium powder, the chromium oxide Cr2O3 contains 5-10 parts of chromium trioxide, the rare earth oxide contains 3-5 parts of rare earth oxide, the cerium dioxide CeO2 contains 2-4 parts of cerium dioxide, the silicon dioxide SiO2 contains 3-5 parts of silicon dioxide, the titanium carbide TiC contains 5-8 parts of titanium carbide, and the zirconium boride ZrB2 contains 2-4 parts of zirconium boride; the nickel-cobalt-chromium-aluminum-yttrium alloy contains 8-10% of aluminum and 0.5-1.5% of yttrium, the mixture Hf:Re contains 1:1 of hafnium powder and rhenium powder, the composite ceramic ZrO2-Y2O3-Al2O3 contains 87% of ZrO2, 8% of Y2O3 and 5% of Al2O3, and the rare earth oxide is a mixture of La2O3 and Nd2O3 with a mass ratio of 2:

1.

2. An oxidation resistant, low wear, heat resistant gas turbine vane coating according to claim 1, characterized in that: The alloy Ni-Co-Cr-Al-Y contains 20-30 parts of nickel-cobalt-chromium-aluminum-yttrium, the composite ceramic ZrO2-Y2O3-Al2O3 contains 30-40 parts of zirconium oxide-yttrium oxide-aluminum oxide, the mixture Hf:Re contains 10-15 parts of hafnium powder and rhenium powder, the chromium oxide Cr2O3 contains 5-10 parts of chromium trioxide, the rare earth oxide contains 3-5 parts of rare earth oxide, the cerium dioxide CeO2 contains 2-4 parts of cerium dioxide, the silicon dioxide SiO2 contains 3-5 parts of silicon dioxide, the titanium carbide TiC contains 5-8 parts of titanium carbide, and the zirconium boride ZrB2 contains 2-4 parts of zirconium boride; the nickel-cobalt-chromium-aluminum-yttrium alloy contains 8-10% of aluminum and 0.5-1.5% of yttrium, the mixture Hf:Re contains 1:1 of hafnium powder and rhenium powder, the composite ceramic ZrO2-Y2O3-Al2O3 contains 87% of ZrO2, 8% of Y2O3 and 5% of Al2O3, and the rare earth oxide is a mixture of La2O3 and Nd2O3 with a mass ratio of 2:

1.

3. A method for preparing an oxidation-resistant, low-abrasion, heat-resistant steam turbine blade coating, applied to the oxidation-resistant, low-abrasion, heat-resistant steam turbine blade coating of any one of claims 1-2, characterized in that, The method comprises the following steps: S1: micronizing and drying the raw materials, and mixing them in a mixer; S2: adding an organic solvent and a binder to the mixed powder, stirring uniformly, and obtaining a coating slurry; S3: uniformly coating the coating slurry on the surface of the turbine blade by plasma spraying; S4: after coating, heat treating the blade to fasten the coating.

4. The method of claim 3, wherein the method further comprises: depositing a first layer of a first material on the surface of the turbine blade; and depositing a second layer of a second material on the first layer of the first material, wherein the first material and the second material are different. In S1, the nickel-cobalt-chromium-aluminum-yttrium alloy, hafnium powder and rhenium powder are respectively ground to micron level; the composite ceramic ZrO2-Y2O3-Al2O3, chromium trioxide, rare earth oxide, cerium dioxide, silicon dioxide, titanium carbide and zirconium boride are dried to remove moisture, and are mixed in a mixer for 6-8 hours to ensure uniform distribution of the raw materials.

5. The method of claim 3, wherein the method further comprises: depositing a first layer of a first material on the surface of the turbine blade; and depositing a second layer of a second material on the first layer of the first material, wherein the first material and the second material are different. In S2, the organic solvent and the binder are added to the mixed powder, the mass ratio of the organic solvent to the powder is controlled to be 2:1, the amount of the binder added is 4%-6% of the mass of the powder, and the coating slurry with viscosity and fluidity is prepared by stirring uniformly.

6. The method of claim 3, wherein the method further comprises: depositing a first layer of a first material on the surface of the turbine blade; and depositing a second layer of a second material on the first layer of the first material, wherein the first material and the second material are different. In S3, the spraying power is controlled to be 30-40 kW, the spraying distance is controlled to be 100-120 mm, and the powder feeding rate is controlled to be 5-8 g / min to ensure uniform thickness of the coating.

7. The method of claim 3, wherein the coating is applied by a process selected from the group consisting of: plasma spray, thermal spray, electron beam physical vapor deposition, sputter deposition, and combinations thereof. S4 comprises the following steps: vacuum hot-press sintering the blade at 900-1100℃ for 2-3 hours under a pressure of 20 MPa; then laser cladding with a wavelength of 1064 nm and a power of 3-4 kW and a spot diameter of 3 mm; after completion, cooling to room temperature to improve the compactness of the coating and the bonding force with the blade substrate.

Images