Thermal barrier coating resistant to high-temperature oxidation and preparation method thereof

Abstract

The invention discloses a thermal barrier coating resistant to high-temperature oxidation and a preparation method thereof, and relates to the technical field of thermal barrier coating materials. According to the preparation method, a NiCoCrAlYHfRu coated coating is prepared on a high-temperature alloy by adopting arc ion plating equipment, and a YSZ / LaZrCeO ceramic surface layer is prepared by adopting electron beam physical vapor deposition equipment. The thermal barrier coating prepared through the technology has a unique columnar crystal structure and meanwhile has good thermal cycle performance. Finally, the anti-oxidation and anti-corrosion requirements of the turbine blade can be met; and the process is simple, industrial production is easy to achieve, and the composite coating is excellent in performance, has application prospects and is suitable for the high-temperature alloy.

Description

Technical Field

[0001] The invention belongs to the technical field of thermal barrier coating materials, and in particular relates to a thermal barrier coating resistant to high temperature oxidation and a preparation method thereof. Background Art

[0002] As the thrust and working efficiency of gas turbines continue to increase, the gas intake temperature is also getting higher and higher, requiring heat-resistant components to have excellent high-temperature oxidation resistance under ultra-high temperature conditions. Engine turbine blades and guide vanes often have problems such as local overburning and overheating. The hot zone of the blade exceeds the normal operating temperature, and the wall temperature can reach 1200℃ for a short time, resulting in excessive oxidation rate of the coating and rapid oxidation failure of the blade surface.

[0003] At present, vacuum arc plating (AIP) technology is mainly used to prepare cladding coatings as bonding layers for high-temperature alloys, and then electron beam physical vapor deposition (EB-PVD) is used to deposit ceramic coatings to obtain thermal barrier coatings. The prepared coatings have good resistance to high-temperature oxidation and thermal corrosion and have been widely used. Thermal barrier coatings (TBC) are usually used in the design of engines and gas turbines to improve their service life and efficiency. Typical thermal barrier coatings are mainly composed of ceramic top coats (TC, mostly yttria partially stabilized zirconia YSZ) and MCrAlY metal bonding layers (BC). The ceramic top coat has a low thermal conductivity and usually provides thermal insulation protection for the components; the metal bonding layer can not only improve the bonding strength between the ceramic top coat and the metal substrate, but also effectively prevent the metal substrate from being oxidized and thermally corroded. Summary of the invention

[0004] Based on the above background, the purpose of the present invention is to provide a composite coating and a preparation method that can withstand higher temperatures and reach 1200°C for oxidation resistance.

[0005] In view of this, according to one aspect of an embodiment of the present invention, a thermal barrier coating resistant to high-temperature oxidation is provided, a NiCoCrAlYHfRu metal bonding layer attached to the surface of a high-temperature alloy, and a YSZ / LaZrCeO double-layer ceramic layer deposited on the metal bonding layer.

[0006] According to one aspect of an embodiment of the present invention, a method for preparing a thermal barrier coating resistant to high-temperature oxidation is also provided. For preparing the coating, an arc ion plating method is used to prepare a NiCoCrAlYHfRu metal bonding layer on the surface of a high-temperature alloy. After diffusion treatment, an electron beam physical vapor deposition is used to prepare a YSZ / LaZrCeO double-layer ceramic layer.

[0007] Optionally, it specifically includes:

[0008] Step S01: Target material preparation: using NiCoCrAlYHfRu target material, the target material is installed on the cathode seat of the vacuum arc coating machine;

[0009] Step S02: Surface activation treatment: The surface of the high temperature alloy is treated by a grinding flow treatment method;

[0010] Step S03: cleaning and drying: cleaning and drying the surface of the high-temperature alloy after the grinding fluid treatment;

[0011] Step S04 NiCoCrAlYHfRu coating deposition: placing the cleaned and dried high-temperature alloy surface in a vacuum, bombarding and heating it, and then depositing a NiCoCrAlYHfRu coating on the high-temperature alloy surface;

[0012] Step S05: diffusion treatment: diffusion treatment of the NiCoCrAlYHfRu coating;

[0013] Step S06 YSZ coating deposition: loading the YSZ target into the deposition chamber of the electron beam physical vapor deposition equipment, and depositing the YSZ coating on the NiCoCrAlYHfRu coating;

[0014] Step S07 LaZrCeO coating deposition: LaZrCeO target material is loaded into the deposition chamber of the electron beam physical vapor deposition equipment, and LaZrCeO coating is deposited on the YSZ coating.

[0015] Optionally, the surface activation treatment in step S02 further includes: adding corundum sand with a particle size of 120 mesh into a liquid sand blowing machine, with a working pressure of 0.2 MPa to 0.5 MPa and a treatment time of 10 min.

[0016] Optionally, step S04 NiCoCrAlYHfRu coating deposition also includes: the vacuum degree reaches 6×10 -3 Pa~7×10 - 3 After Pa, the surface of the high-temperature alloy is bombarded and heated, the arc current I = 550A ~ 750A, and the bias voltage U = 200V ~ 300V.

[0017] Optionally, step S04 NiCoCrAlYHfRu coating deposition further includes: depositing a NiCoCrAlYHfRu coating on the surface of the high temperature alloy, arc current I = 550A ~ 750A, bias voltage U = 20V ~ 30V, deposition time is 100min ~ 150min, vacuum degree is 6×10 -3 Pa~7×10 -3 Pa.

[0018] Optionally, step S05 diffusion treatment: the NiCoCrAlYHfRu coating is diffused with a vacuum degree of 1×10 -2 Pa~1×10 -3 Pa, temperature 850-900℃, time 3h.

[0019] Optionally, step S06 YSZ coating deposition further includes: YSZ coating deposition parameters are vacuum degree less than 6×10 -2 Pa, the electron beam current intensity is 1.4-1.6A, the temperature is 800-1000℃, and the evaporation time is 20-30min.

[0020] Optionally, step S07 LaZrCeO coating deposition further includes: LaZrCeO coating deposition parameters are vacuum degree less than 6×10 -2 Pa, the electron beam current intensity is 1.2-1.4A, the temperature is 800-1000℃, and the evaporation time is 30-40min.

[0021] Optionally, the high temperature alloy is DD9 alloy.

[0022] The invention has the following beneficial effects: (1) the NiCoCrAlYHfRu coating is prepared by arc ion plating, which has a smaller thermal expansion coefficient, has good compatibility with the ceramic surface layer and the alloy substrate, and does not cause cracking of the coating or interface instability during use; (2) the double-layer ceramic layer YSZ / LaZrCeO has good resistance to high-temperature oxidation corrosion, and improves the resistance to high-temperature oxidation corrosion of the matrix alloy at high temperatures; (3) has good thermal bonding strength with the matrix alloy; (4) has a low diffusion coefficient, and can slow down the diffusion of elements such as Al and Cr from the coating to the matrix alloy at high temperatures, and can prevent metal elements such as Ti, Mo, W, and Ni from the alloy substrate to diffuse into the coating. At the same time, since the arc ion plating (ARC) method has the characteristics of moderate deposition rate, good coating density, and metallurgical bonding with the substrate, the coating prepared by the ARC method has strong compatibility with the substrate, good thickness and density, thereby greatly improving the strain capacity of the coating. The NiCoCrAlYHfRu coating is prepared by vacuum arc plating technology. The preparation process is simple, efficient and low-cost, which can meet the requirements of long-life protective coating on the outer surface of turbine blades. The thermal barrier coating prepared by EB-PVD is a typical columnar crystal structure with a high strain tolerance, which can reduce the impact of thermal stress on the coating and has a relatively longer thermal cycle life. The LaZrCeO thermal barrier coating has no phase change after long-term heat treatment at 1500℃ and has high phase stability. Their thermal expansion coefficient is close to that of YSZ, and they have lower thermal conductivity and better fracture toughness.

[0023] The anti-oxidation test was carried out in accordance with the provisions of HB5258-2000, with a test temperature of 1200°C and a test time of 200h. Finally, the surface condition of the sample was good, with an average oxidation rate of less than 0.1g / (m2·h), reaching the complete anti-oxidation level. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The present invention is a flowchart of a method for preparing a thermal barrier coating resistant to high-temperature oxidation according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] According to one aspect of an embodiment of the present invention, a thermal barrier coating resistant to high temperature oxidation is provided, comprising a NiCoCrAlYHfRu metal bonding layer attached to the surface of a high temperature alloy, and a YSZ / LaZrCeO double-layer ceramic layer deposited on the metal bonding layer.

[0027] Nickel (Ni) and cobalt (Co) are the main metal elements of MCrAlY coatings. They play a bonding and supporting role in the coating and affect the phase change and high temperature oxidation performance of the coating.

[0028] Chromium (Cr) plays an anti-oxidation and anti-corrosion role in MCrAlY coating. It can form a dense Cr2O3 protective layer to prevent further penetration of oxygen and corrosive substances.

[0029] Aluminum (Al) forms an Al2O3 protective layer in the coating, which is an oxide with high thermal and chemical stability. It can effectively prevent the diffusion of cations and oxygen ions, thereby protecting the substrate from high-temperature oxidation and corrosion.

[0030] Yttrium (Y), as an active element, can improve the adhesion of the surface oxide film and prevent the coating from falling off. Y element promotes the oxidation of Al element and generates Al2O3 with good high temperature oxidation resistance, thereby improving the high temperature resistance of the coating.

[0031] Hafnium (Hf) is used to improve the anti-oxidation performance. The oxide of the Hf element is unevenly distributed in the Al2O3 oxide film, which improves the stability of the protective oxide film of the coating, thereby enhancing the anti-oxidation performance of the coating. As well as enhancing the protectiveness of the coating, the presence of the Hf element improves the protectiveness of the coating, making it perform better in high temperature environments.

[0032] Ruthenium (Ru) is a rare metal with a high melting point (2334°C) and good mechanical stability. Adding ruthenium to metal coatings can significantly improve the hardness and corrosion resistance of the material.

[0033] According to another aspect of an embodiment of the present invention, a method for preparing a thermal barrier coating resistant to high-temperature oxidation is provided, comprising preparing the coating, preparing a NiCoCrAlYHfRu metal bonding layer on the surface of a high-temperature alloy by an arc ion plating method, and then preparing a YSZ / LaZrCeO double-layer ceramic layer by electron beam physical vapor deposition after diffusion treatment.

[0034] Furthermore, it specifically includes:

[0035] Step S01: Target material preparation: using NiCoCrAlYHfRu target material, the target material is installed on the cathode seat of the vacuum arc coating machine;

[0036] Step S02: Surface activation treatment: The surface of the high temperature alloy is treated by a grinding flow treatment method;

[0037] Step S03: cleaning and drying: cleaning and drying the surface of the high-temperature alloy after the grinding fluid treatment;

[0038] Step S04 NiCoCrAlYHfRu coating deposition: placing the cleaned and dried high-temperature alloy surface in a vacuum, bombarding and heating it, and then depositing a NiCoCrAlYHfRu coating on the high-temperature alloy surface;

[0039] Step S05: diffusion treatment: diffusion treatment of the NiCoCrAlYHfRu coating;

[0040] Step S06 YSZ coating deposition: loading the YSZ target into the deposition chamber of the electron beam physical vapor deposition equipment, and depositing the YSZ coating on the NiCoCrAlYHfRu coating;

[0041] Step S07 LaZrCeO coating deposition: LaZrCeO target material is loaded into the deposition chamber of the electron beam physical vapor deposition equipment, and LaZrCeO coating is deposited on the YSZ coating.

[0042] Furthermore, the surface activation treatment in step S02 also includes: adding corundum sand with a particle size of 120 mesh into a liquid sand blowing machine, with a working pressure of 0.2MPa to 0.5MPa and a treatment time of 10min.

[0043] Furthermore, step S04 NiCoCrAlYHfRu coating deposition also includes: the vacuum degree reaches 6×10 -3 Pa~7×10 -3After Pa, the surface of the high-temperature alloy is bombarded and heated, the arc current I = 550A ~ 750A, and the bias voltage U = 200V ~ 300V.

[0044] Further, step S04 NiCoCrAlYHfRu coating deposition also includes: depositing NiCoCrAlYHfRu coating on the surface of the high temperature alloy, arc current I = 550A ~ 750A, bias voltage U = 20V ~ 30V, deposition time is 100min ~ 150min, vacuum degree is 6×10 -3 Pa~7×10 -3 Pa.

[0045] Further, step S05 diffusion treatment: the NiCoCrAlYHfRu coating is diffused, and the vacuum degree is 1×10 - 2 Pa~1×10 -3 Pa, temperature 850-900℃, time 3h.

[0046] Furthermore, step S06 YSZ coating deposition also includes: YSZ coating deposition parameters are vacuum degree less than 6×10 - 2 Pa, the electron beam current intensity is 1.4-1.6A, the temperature is 800-1000℃, and the evaporation time is 20-30min.

[0047] Furthermore, step S07 LaZrCeO coating deposition also includes: LaZrCeO coating deposition parameters are vacuum degree less than 6×10 -2 Pa, the electron beam current intensity is 1.2-1.4A, the temperature is 800-1000℃, and the evaporation time is 30-40min.

[0048] Furthermore, the high temperature alloy is DD9 alloy.

[0049] The present invention adopts arc ion plating technology and NiCoCrAlYHfRu target material to achieve the deposition of NiCoCrAlYHfRu coating. The formed NiCoCrAlYHfRu coating has a dense structure, good bonding with the substrate, and a low thermal expansion coefficient under 1200°C high-temperature oxidation conditions, which improves the matching with the alloy substrate and the ceramic surface layer, and enhances the bonding strength and service life of the thermal barrier coating. Electron beam physical vapor phase technology is adopted, and YSZ / LaZrCeO target material is used to achieve the deposition of YSZ / LaZrCeO coating. The thermal barrier coating prepared by this technology has a unique columnar crystal structure and good thermal cycle performance. It can ultimately meet the oxidation resistance and corrosion resistance requirements of turbine blades; and the process is streamlined, and it is easy to realize industrial production. It is a composite coating with excellent performance and application prospects, suitable for high-temperature alloys.

[0050] Example

[0051] Step 1: Single crystal high temperature alloy turbine blades are used as the substrate, and the substrate alloy is DD9 alloy. The NiCoCrAlYHfRu coating is prepared on the DD9 alloy using arc ion plating equipment, and the NiCoCrAlYHfRu target is used to achieve the deposition of the NiCoCrAlYHfRu coating. Raw material selection, NiCoCrAlYHfRu target material is used, and the target material is installed on the cathode seat of the vacuum arc coating machine.

[0052] Step 2: Activate the substrate surface by grinding flow treatment. Add 120-mesh corundum sand into the liquid sand blasting machine. The working pressure is 0.2MPa-0.5MPa and the treatment time is 10min.

[0053] Step 3: Wash and dry.

[0054] Step 4: Use a fixture to load the substrate into the vacuum chamber of the arc ion plating equipment.

[0055] Step 5: The substrate to be coated is mounted in a vacuum chamber and evacuated. After the vacuum reaches 6×10-3Pa~7×10-3Pa, bombard heating is performed, the arc current I=550A~750A, the bias voltage U=200V~300V, and the bombardment time is 5min. Then, a layer of NiCoCrAlYHfRu is deposited on the surface of the substrate, the arc current I=550A~750A, the bias voltage U=20V~30V, the deposition time is 100min~150min, and the vacuum reaches 6×10 -3 Pa~7×10 -3 Pa.

[0056] Step 6: Diffusion treatment of the substrate with NiCoCrAlYHfRu coating, diffusion treatment, vacuum degree 10 - 2 Pa~10 -3 Pa, temperature 850-900℃, time 3h.

[0057] Step 7: Load the YSZ target into the deposition chamber of the electron beam physical vapor deposition equipment. The vacuum degree of the deposition chamber is <6×10 - 2 Pa; electron beam current intensity 1.4-1.6A; substrate temperature 800-1000℃; evaporation time 20-30min.

[0058] Step 8: LaZrCeO target is loaded into the deposition chamber of the electron beam physical vapor deposition equipment. The vacuum degree of the deposition chamber is <6×10 -2Pa; electron beam current intensity 1.2-1.4A; substrate temperature 800-1000℃; evaporation time 30-40min.

[0059] The anti-oxidation test was carried out in accordance with the provisions of HB5258-2000, with a test temperature of 1200°C and a test time of 200h. Finally, the surface condition of the sample was good, with an average oxidation rate of less than 0.1g / (m2·h), reaching the complete anti-oxidation level.

[0060] The above is only a specific embodiment of the present invention, and the present invention is described in detail. The unexplained part is a conventional technology. However, the protection scope of the present invention is not limited to this. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A thermal barrier coating resistant to high temperature oxidation, characterized in that: A NiCoCrAlYHfRu metal bonding layer attached to the surface of a high temperature alloy, and a YSZ / LaZrCeO double-layer ceramic layer deposited on the metal bonding layer.

2. A method for preparing a thermal barrier coating resistant to high temperature oxidation, characterized in that: For preparing the coating as claimed in claim 1, a NiCoCrAlYHfRu metal bonding layer is prepared on the surface of a high-temperature alloy by an arc ion plating method, and after diffusion treatment, a YSZ / LaZrCeO double-layer ceramic layer is prepared by electron beam physical vapor deposition.

3. The method according to claim 2, characterized in that Specifically include: Step S01: Target material preparation: using NiCoCrAlYHfRu target material, the target material is installed on the cathode seat of the vacuum arc coating machine; Step S02: Surface activation treatment: The surface of the high temperature alloy is treated by a grinding flow treatment method; Step S03: cleaning and drying: cleaning and drying the surface of the high-temperature alloy after the grinding fluid treatment; Step S04 NiCoCrAlYHfRu coating deposition: placing the cleaned and dried high-temperature alloy surface in a vacuum, bombarding and heating it, and then depositing a NiCoCrAlYHfRu coating on the high-temperature alloy surface; Step S05: diffusion treatment: diffusion treatment of the NiCoCrAlYHfRu coating; Step S06 YSZ coating deposition: loading the YSZ target into the deposition chamber of the electron beam physical vapor deposition equipment, and depositing the YSZ coating on the NiCoCrAlYHfRu coating; Step S07 LaZrCeO coating deposition: LaZrCeO target material is loaded into the deposition chamber of the electron beam physical vapor deposition equipment, and LaZrCeO coating is deposited on the YSZ coating.

4. The method according to claim 3, characterized in that: Step S02 of surface activation treatment also includes: adding corundum sand with a particle size of 120 mesh into a liquid sand blowing machine, with a working pressure of 0.2MPa to 0.5MPa and a treatment time of 10 minutes.

5. The method according to claim 3, characterized in that: Step S04 NiCoCrAlYHfRu coating deposition also includes: vacuum degree reaches 6×10 -3 Pa~7×10 -3 After Pa, the surface of the high-temperature alloy is bombarded and heated, the arc current I = 550A ~ 750A, and the bias voltage U = 200V ~ 300V.

6. The method according to claim 3, characterized in that Step S04 NiCoCrAlYHfRu coating deposition also includes: depositing NiCoCrAlYHfRu coating on the surface of the high temperature alloy, arc current I = 550A ~ 750A, bias voltage U = 20V ~ 30V, deposition time is 100min ~ 150min, vacuum degree is 6×10 -3 Pa~7×10 -3 Pa.

7. The method according to claim 3, characterized in that Step S05: Diffusion treatment: Diffusion treatment of NiCoCrAlYHfRu coating, vacuum degree 1×10 -2 Pa~1×10 -3 Pa, temperature 850-900℃, time 3h.

8. The method according to claim 3, characterized in that Step S06 YSZ coating deposition also includes: The YSZ coating deposition parameters are as follows: the vacuum degree is less than 6×10 -2 Pa, the electron beam current intensity is 1.4-1.6A, the temperature is 800-1000℃, and the evaporation time is 20-30min.

9. The method according to claim 3, characterized in that: Step S07 LaZrCeO coating deposition also includes: LaZrCeO coating deposition parameters are vacuum degree less than 6×10 -2 Pa, the electron beam current intensity is 1.2-1.4A, the temperature is 800-1000℃, and the evaporation time is 30-40min.

10. The method according to claim 3, characterized in that The high temperature alloy is DD9 alloy.

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