A method for preparing a nickel-platinum-aluminum bonding layer having a nickel-tungsten-rhenium diffusion barrier coating

Abstract

The present invention relates to a method for preparing a nickel-platinum-aluminum bonding layer with a nickel-tungsten-rhenium diffusion barrier coating, comprising: performing nickel-tungsten-rhenium electroplating on the surface of a substrate to obtain a nickel-tungsten-rhenium layer; performing platinum electroplating on the nickel-tungsten-rhenium layer to obtain a platinum layer with a nickel-tungsten-rhenium diffusion barrier coating; performing vacuum annealing on the platinum layer; and performing aluminizing on the platinum layer after the vacuum annealing to obtain a nickel-platinum-aluminum bonding layer with a nickel-tungsten-rhenium diffusion barrier coating. The purpose of the method for preparing a nickel-platinum-aluminum bonding layer with a nickel-tungsten-rhenium diffusion barrier coating is to solve the problem that during the service of an engine blade or a gas turbine blade, the high-temperature mechanical properties of the substrate are damaged and the coating cracks and falls off due to severe element interdiffusion in the coating.

Description

Technical Field

[0001] The invention relates to the technical field of thermal barrier coatings, and in particular to a method for preparing a nickel-platinum-aluminum bonding layer having a nickel-tungsten-rhenium diffusion barrier coating. Background Art

[0002] Because of its excellent antioxidant and hot corrosion resistance, (Ni,Pt)Al coatings are widely used in key hot end components of aero engines and gas turbines, such as turbine rotors and guide blades. Due to the high aluminum content in the (Ni,Pt)Al coating and the high nickel content in the substrate, when the blade is in service in a high temperature environment, serious element interdiffusion will occur between the coating and the substrate. For the substrate, the aluminum diffused into the substrate will destroy the coherent structure of the nickel lattice in the substrate, causing the γ to transform into the γ′ phase. The solubility of the refractory elements in the γ′ phase is low, so they precipitate to form TCP (Topologically Close-Packed Phases), and the secondary reaction zone in the TCP phase is a needle-like structure, which causes local stress concentration at the tip, resulting in a significant decrease in the high-temperature mechanical properties (especially creep and fatigue) of the single crystal substrate. For the coating, the diffusion of aluminum causes the aluminum-rich NiAl phase in the coating to transform into the Al-poor Ni3Al phase, and eventually degenerate into a γ-Ni phase without antioxidant properties. Therefore, the diffusion of aluminum will cause the aluminum content in the coating to decrease continuously, which will reduce the oxidation resistance of the coating. In short, this mutual diffusion of elements will cause both the substrate and the coating to degrade and lose their ability to resist high-temperature oxidation.

[0003] In addition to the diffusion of aluminum, a large amount of refractory elements in the Ni3Al-based intermetallic compound are dissolved in the γ phase and γ′ phase of the matrix. During the high-temperature oxidation process, the refractory elements in the matrix (such as Mo, W) are easy to diffuse outward to the coating and form volatile oxides (such as MoO3) on the surface of the coating, which destroys the adhesion of the thermally grown oxide film (TGO) and its integrity, causing the oxide film on the coating to crack and peel off. Once the bonding layer cracks and peels off, the outer ceramic layer will also peel off, making the entire thermal barrier coating bonding layer system ineffective.

[0004] During the service of engine blades or gas turbine blades, serious element interdiffusion will occur in the coating, which not only endangers the high-temperature mechanical properties of the substrate, but also causes the coating to crack and fall off, thereby affecting the life of the entire thermal barrier coating system.

[0005] Therefore, the inventors provide a method for preparing a nickel-platinum-aluminum bonding layer having a nickel-tungsten-rhenium diffusion barrier coating. Summary of the invention

[0006] (1) Technical issues to be solved

[0007] The embodiment of the present invention provides a method for preparing a nickel-platinum-aluminum bonding layer with a nickel-tungsten-rhenium diffusion barrier coating, which solves the technical problem that during the service of engine blades or gas turbine blades, severe element interdiffusion in the coating causes damage to the high-temperature mechanical properties of the substrate and causes cracking and shedding of the coating.

[0008] (2) Technical solution

[0009] The present invention provides a method for preparing a nickel-platinum-aluminum bonding layer having a nickel-tungsten-rhenium diffusion barrier coating, comprising the following steps:

[0010] Electroplating nickel-tungsten-rhenium on the surface of the substrate to obtain a nickel-tungsten-rhenium layer;

[0011] Platinum electroplating is performed on the nickel-tungsten-rhenium layer to obtain a platinum layer having a nickel-tungsten-rhenium diffusion barrier coating;

[0012] The platinum layer is subjected to vacuum annealing treatment;

[0013] The platinum layer after vacuum annealing is subjected to aluminum infiltration treatment to obtain a nickel-platinum-aluminum bonding layer with a nickel-tungsten-rhenium diffusion barrier coating.

[0014] Further, the nickel-tungsten-rhenium electroplating is performed on the surface of the substrate to obtain the nickel-tungsten-rhenium layer, specifically:

[0015] The substrate is placed in an electroplating solution, wherein the electroplating solution is a mixed solution of nickel sulfate hexahydrate, sodium chloride, boron dioxide, sodium sulfate, potassium perrhenate, sodium tungstate dihydrate, citric acid and deionized water.

[0016] Furthermore, the mass ratio of each component in the electrolytic solution is: 6.72-8.78wt% of nickel sulfate hexahydrate, 1.01-1.43wt% of sodium chloride, 1.26-1.59wt% of boron dioxide, 4.37-5.16wt% of sodium sulfate, 0.67-1.19wt% of potassium perrhenate, 0.84-1.35wt% of sodium tungstate dihydrate, 1.01-1.11wt% of citric acid, and the rest is deionized water.

[0017] Furthermore, the pH of the electrophoresis solution is 5-6.

[0018] Furthermore, the anode is a high-purity nickel plate, and the current density of the cathode is 4-6 mA / cm 2 , the deposition efficiency is 5 to 7 μm / h.

[0019] Furthermore, the electroplating temperature is 60°C.

[0020] Furthermore, before the nickel-tungsten-rhenium electroplating is performed on the surface of the substrate to obtain the nickel-tungsten-rhenium layer, the process further includes: performing surface pretreatment on the substrate.

[0021] Further, the nickel-tungsten-rhenium layer is subjected to platinum electroplating to obtain a platinum layer having a nickel-tungsten-rhenium diffusion barrier coating, specifically:

[0022] The nickel-tungsten-rhenium layer electroplated on the substrate is placed in a platinum plating solution for electroplating; wherein the anode is a high-purity platinum sheet and the current density of the cathode is 0.2-0.7A / dm 2 .

[0023] Further, the platinum layer is subjected to vacuum annealing treatment, specifically:

[0024] The platinum layer electroplated on the nickel-tungsten-rhenium layer is cleaned and dried in sequence, and then placed in a vacuum furnace for heat treatment for a set time, and cooled along with the furnace.

[0025] Furthermore, the platinum layer after vacuum annealing is subjected to aluminizing treatment, specifically:

[0026] The platinum layer electroplated on the nickel-tungsten-rhenium layer is aluminized by an embedded aluminizing method; wherein the components of the aluminizing agent include aluminum powder, NaF, KHF2, NH4Cl and Al2O3 powder.

[0027] (3) Beneficial effects

[0028] In summary, the present invention coats a layer of nickel, tungsten and rhenium on the substrate by electroplating before preparing the conventional (Ni, Pt)Al coating. This layer of nickel, tungsten and rhenium can slow down the mutual diffusion of nickel in the substrate and aluminum in the coating during the subsequent high-temperature oxidation, while preventing the insoluble elements in the substrate from diffusing outward, thereby improving the viscosity of the thermally grown film and achieving the purpose of preventing the bonding layer from cracking and peeling. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments of the present invention are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 It is a schematic flow chart of a method for preparing a nickel-platinum-aluminum bonding layer having a nickel-tungsten-rhenium diffusion barrier coating provided by an embodiment of the present invention;

[0031] Figure 2 Schematic diagram of the microstructure of a nickel-tungsten-rhenium coating electroplated for 40 minutes provided in Example 1 of the present invention;

[0032] Figure 3It is a comparison diagram of the constant temperature oxidation kinetic curves of a β-(Ni, Pt)Al coating with a 4 μm nickel-tungsten-rhenium diffusion barrier coating and a conventional β-(Ni, Pt)Al coating at 1100° C. provided in Example 1 of the present invention;

[0033] Figure 4 Schematic diagram of the microstructure of a nickel-tungsten-rhenium coating electroplated for 1 hour provided in Example 2 of the present invention;

[0034] Figure 5 It is a comparison diagram of the constant temperature oxidation kinetic curves of a β-(Ni, Pt)Al coating with a 7 μm nickel-tungsten-rhenium diffusion barrier coating and a conventional β-(Ni, Pt)Al coating at 1100° C. provided in Example 2 of the present invention;

[0035] Figure 6 This is a schematic diagram of the microstructure of a nickel-tungsten-rhenium coating electroplated for 1.5 hours provided in Example 3 of the present invention;

[0036] Figure 7 It is a comparison chart of the isothermal oxidation kinetic curves of a β-(Ni, Pt)Al coating with a 9μm nickel-tungsten-rhenium diffusion barrier coating and a conventional β-(Ni, Pt)Al coating at 1100°C provided in Example 3 of the present invention. DETAILED DESCRIPTION

[0037] The following is a further detailed description of the embodiments of the present invention in conjunction with the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to exemplarily illustrate the principles of the present invention, but cannot be used to limit the scope of the present invention, that is, the present invention is not limited to the described embodiments, and covers any modification, replacement and improvement of parts, components and connection modes without departing from the spirit of the present invention.

[0038] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0039] Figure 1 1 is a flow chart of a method for preparing a nickel-platinum-aluminum bonding layer having a nickel-tungsten-rhenium diffusion barrier coating provided by an embodiment of the present invention. The method may include the following steps:

[0040] S100, performing nickel-tungsten-rhenium electroplating on the surface of the substrate to obtain a nickel-tungsten-rhenium layer;

[0041] S200, platinum electroplating the nickel-tungsten-rhenium layer to obtain a platinum layer having a nickel-tungsten-rhenium diffusion barrier coating;

[0042] S300, performing vacuum annealing treatment on the platinum layer;

[0043] S400, performing aluminum infiltration on the platinum layer after vacuum annealing to obtain a nickel-platinum-aluminum bonding layer having a nickel-tungsten-rhenium diffusion barrier coating.

[0044] In the above embodiment, in step S300, the test piece with the nickel and platinum layers is taken out, washed with deionized water, and dried. Then, it is placed in a vacuum furnace for heat treatment at a temperature of 1000-1100°C for 2-6 hours, and the vacuum degree in the furnace is less than 2×10 -2 Pa, and then cooled in the furnace. The purpose of this vacuum annealing step is to obtain a coating with a tight bonding surface.

[0045] The diffusion rate of aluminum in NiAl is 2.4×10 -14 m / s, while the diffusion rate of aluminum in tungsten-rhenium alloy is only 1.62×10 -16 m / s, it is obvious that aluminum is more difficult to diffuse in tungsten-rhenium alloy. When the thermal oxidation cycle is carried out to 500 cycles, the atomic numbers of aluminum, nickel and platinum are 22%, 59.1% and 10.7% (the rest are high-temperature alloy elements Co, W, Mo, Ta, etc.) at 5μm above the diffusion barrier coating. From the composition, it can be seen that the nickel-platinum-aluminum bonding layer at 5μm is still β-(Ni,Pt)Al phase, while the aluminum content is only 15.5% at 5μm above the interdiffusion zone without the diffusion barrier coating. At this time, it can be judged that the (Ni,Pt)Al coating close to the interdiffusion layer has degraded.

[0046] The nickel-platinum-aluminum bonding layer prepared by the present invention needs to be subjected to a high-temperature cyclic oxidation test. The test temperature is 1100°C, and the single cycle time is 1 hour (50 minutes of insulation in the furnace, 10 minutes of cooling outside the furnace, and air cooling). After a certain number of cycles, the sample is weighed with a precision balance and the weight is recorded.

[0047] The experiment shows that during the 1100℃ oxidation experiment, by 1000h, the thickness of the nickel-tungsten-rhenium coating was reduced from the original 8μm to 4.6μm, and the atomic ratio of nickel:rhenium changed from the original 84:16 to 67:33. The nickel content was significantly reduced. Part of the nickel in the diffusion barrier coating played a role in replacing the nickel in the substrate and interdiffusion with the nickel-platinum-aluminum bonding layer. Moreover, after 700 cycles at 1000℃, the nickel content in the interdiffusion layer under the diffusion barrier coating was significantly less than the nickel in the interdiffusion layer in the ordinary (Ni,Pt)Al coating.

[0048] In the 1100℃ cyclic oxidation test, after 1000 cycles, the (Ni,Pt)Al coating without diffusion barrier had local peeling and more cracks, while a thinner and less rough oxide layer was observed on the nickel-platinum-aluminum bonding layer with diffusion barrier layer, indicating that the (Ni,Pt)Al with diffusion barrier coating has better TGO adhesion. The main reason is that the aluminum element in the (Ni,Pt)Al coating without diffusion barrier not only forms TGO, but also diffuses into the substrate, consuming more aluminum, and the reduction of aluminum element causes the coating to transform from β phase to γ′ phase, and during the phase change process, a volume shrinkage of 38% will occur. Therefore, the diffusion barrier coating can improve the adhesion of TGO and reduce the wrinkling and peeling of the (Ni,Pt)Al coating.

[0049] As an optional embodiment, in step S100, nickel tungsten rhenium electroplating is performed on the surface of the substrate to obtain a nickel tungsten rhenium layer, specifically: the substrate is placed in an electroplating solution; wherein the electroplating solution is a mixed solution of nickel sulfate hexahydrate, sodium chloride, boron dioxide, sodium sulfate, potassium perrhenate, sodium tungstate dihydrate, citric acid and deionized water.

[0050] Specifically, nickel sulfate hexahydrate, potassium perrhenate and sodium tungstate dihydrate are used as sources of nickel ions, rhenium ions and tungsten ions, sodium chloride is a conductive salt, and an appropriate amount of boron can improve the electroplating efficiency of tungsten and rhenium. Theoretically, the potential difference between nickel and tungsten and rhenium is large, and co-deposition cannot be achieved. However, due to the empty orbits of transition elements, nickel and tungsten and rhenium can exist in the form of complexes. In the present invention, citric acid is used as a complexing agent for nickel and tungsten.

[0051] As an optional embodiment, the mass ratio of each component in the electrolytic solution is: 6.72-8.78wt% nickel sulfate hexahydrate, 1.01-1.43wt% sodium chloride, 1.26-1.59wt% boron dioxide, 4.37-5.16wt% sodium sulfate, 0.67-1.19wt% potassium perrhenate, 0.84-1.35wt% sodium tungstate dihydrate, 1.01-1.11wt% citric acid, and the rest is deionized water.

[0052] The specific mass percentages of the components in the nickel-tungsten-rhenium electroplating solution are given above. The selection of the components can enable the nickel-tungsten-rhenium electroplating layer to solve the corresponding problems.

[0053] Specifically, the anode of the electroplating is a high-purity nickel plate (not less than 99.9%) or an insoluble anode, the pH of the solution is 5-6, the temperature is 40-60°C, and the current density of the cathode is 4-6 mA / cm 2 , the deposition efficiency is 5 to 7 μm / h.

[0054] As an optional implementation, before performing nickel-tungsten-rhenium electroplating on the surface of the substrate to obtain the nickel-tungsten-rhenium layer, the method further includes: performing surface pretreatment on the substrate.

[0055] Specifically, the surface of the test piece was sandblasted, and then the test piece was alkaline washed, with a solution of 130 g / L NaOH and the rest being deionized water, at a temperature of 60° C., for 5 minutes.

[0056] As an optional embodiment, in step S200, the nickel-tungsten-rhenium layer is subjected to platinum electroplating to obtain a platinum layer having a nickel-tungsten-rhenium diffusion barrier coating, specifically, the nickel-tungsten-rhenium layer electroplated on the substrate is placed in a platinum plating solution for electrodeposition; wherein the anode is a high-purity platinum sheet, and the current density of the cathode is 0.2-0.7A / dm 2 .

[0057] Specifically, the process parameters of electrodeposition are: current density is 0.2-0.7A / dm 2 , pH value is 10.2-10.8 at 20℃ (can be adjusted with NaOH), the main salt of the plating solution is tetraammineplatinum dihydrogenphosphate (CAS127733-98-6), the electroplating temperature is 91-95℃, the anode is two high-purity platinum sheets (not less than 99.9%), and the concentration of platinum in the plating solution should not be less than 4g / L.

[0058] As an optional implementation, in step S400, the platinum layer after vacuum annealing is subjected to aluminum infiltration treatment, specifically: the platinum layer electroplated on the nickel tungsten rhenium layer is aluminum infiltrated by an embedded infiltration method; wherein the components of the aluminizing agent include aluminum powder, NaF, KHF2, NH4Cl and Al2O3 powder.

[0059] Specifically, the aluminizing was performed by embedding aluminizing, the aluminizing agent was 1.5% aluminum powder, 0.6% NaF, 0.2% KHF2, 0.1% NH4Cl, and the rest was Al2O3 powder. The aluminizing temperature was 1050°C, the time was 4 hours, and the sample was cooled with the furnace.

[0060] Example 1

[0061] 1) Pretreatment: The surface of the test piece was sandblasted, and then the test piece was alkaline washed, the solution was 130g / L NaOH, the rest was deionized water, the temperature was 60°C, and the time was 5 minutes;

[0062] 2) Electroplating of nickel, tungsten and rhenium: The plating solution consists of 8.19wt% nickel sulfate hexahydrate, 1.23wt% sodium chloride, 1.64wt% boron dioxide, 4.51wt% sodium sulfate, 0.81wt% potassium perrhenate, 0.92wt% sodium tungstate dihydrate, 1.06wt% citric acid, and the rest is deionized water; the anode is a high-purity nickel plate (not less than 99.9%), the pH of the solution is 5.5, the temperature is 60°C, and the cathode current density is 5mA / cm 2 The electroplating time is 40 minutes (the nickel-tungsten-rhenium Figure 2 shown);

[0063] 3) Platinum electroplating: Place the test piece with nickel layer into platinum plating solution for electroplating; process parameters are: current density 0.5A / dm 2 , pH value is 10.5 at 20℃ (adjusted with NaOH), the main salt of the plating solution is tetraammine platinum hydrogen ammonium phosphate (CAS127733-98-6), the electroplating temperature is 95℃, the anode is two high-purity platinum sheets (not less than 99.9%), and the concentration of platinum in the plating solution should not be less than 4g / L;

[0064] 4) Annealing homogenization: The test piece with nickel and platinum layers was taken out, washed with deionized water, dried, and then placed in a vacuum furnace for heat treatment at 1000°C for 3 hours. The vacuum degree in the furnace was less than 2×10 -2 Pa, cooling with the furnace; the purpose of this step of vacuum annealing is mainly to obtain a coating with a tight bonding surface;

[0065] 5) Aluminizing: Aluminizing was carried out by embedding method. The aluminizing agent was 1.5% aluminum powder, 0.6% NaF, 0.2% KHF2, 0.1% NH4Cl, and the rest was Al2O3 powder. The temperature was 1050°C, the time was 4 hours, and the sample was cooled with the furnace.

[0066] In summary, the coating prepared in Example 1 needs to be subjected to a high-temperature cyclic oxidation test. The test temperature is 1100°C, and the single cycle time is 1h (50min of heat preservation in the furnace, 10min of cooling outside the furnace, and air cooling). After a certain number of cycles, the sample is weighed and the weight is recorded using a precision balance. The weight change is compared with the weight change of the coating without the diffusion barrier layer. Figure 3 shown.

[0067] Example 2

[0068] 1) Pretreatment: The surface of the test piece was sandblasted, and then the test piece was alkaline washed, the solution was 130g / L NaOH, the rest was deionized water, the temperature was 60°C, and the time was 5 minutes;

[0069] 2) Electroplating of nickel, tungsten and rhenium: The plating solution consists of 8.19wt% nickel sulfate hexahydrate, 1.23wt% sodium chloride, 1.64wt% boron dioxide, 4.51wt% sodium sulfate, 0.81wt% potassium perrhenate, 0.92wt% sodium tungstate dihydrate, 1.06wt% citric acid, and the rest is deionized water; the anode is a high-purity nickel plate (not less than 99.9%), the pH of the solution is 5.5, the temperature is 60°C, and the cathode current density is 5mA / cm 2 , the electroplating time is 1 hour (the nickel tungsten rhenium obtained is as follows Figure 4 shown);

[0070] 3) Platinum electroplating: Place the test piece with nickel layer into platinum plating solution for electroplating; process parameters are: current density 0.5A / dm 2 , pH value is 10.5 at 20℃ (adjusted with NaOH), the main salt of the plating solution is tetraammine platinum hydrogen ammonium phosphate (CAS127733-98-6), the electroplating temperature is 95℃, the anode is two high-purity platinum sheets (not less than 99.9%), and the concentration of platinum in the plating solution should not be less than 4g / L;

[0071] 4) Annealing homogenization: Take out the test piece with nickel and platinum layers, wash with deionized water, and dry. Then put it into a vacuum furnace for heat treatment at 1000℃ for 3 hours. The vacuum degree in the furnace is less than 2×10 -2 Pa, cooling with the furnace; the purpose of this step of vacuum annealing is mainly to obtain a coating with a tight bonding surface;

[0072] 5) Aluminizing: Aluminizing was carried out by embedding method. The aluminizing agent was 1.5% aluminum powder, 0.6% NaF, 0.2% KHF2, 0.1% NH4Cl, and the rest was Al2O3 powder. The temperature was 1050°C, the time was 4 hours, and the sample was cooled with the furnace.

[0073] In summary, the coating prepared in Example 2 needs to be subjected to a high-temperature cyclic oxidation test. The test temperature is 1100°C, and the single cycle time is 1 hour (50 minutes of heat preservation in the furnace, 10 minutes of cooling outside the furnace, and air cooling). After a certain number of cycles, the sample is weighed and the weight is recorded using a precision balance. The weight change is compared with the weight change of the coating without the diffusion barrier layer. Figure 5 shown.

[0074] Example 3

[0075] 1) Pretreatment: The surface of the test piece was sandblasted, and then the test piece was alkaline washed, the solution was 130g / L NaOH, the rest was deionized water, the temperature was 60°C, and the time was 5 minutes;

[0076] 2) Electroplating of nickel, tungsten and rhenium: The plating solution consists of 8.19wt% nickel sulfate hexahydrate, 1.23wt% sodium chloride, 1.64wt% boron dioxide, 4.51wt% sodium sulfate, 0.81wt% potassium perrhenate, 0.92wt% sodium tungstate dihydrate, 1.06wt% citric acid, and the rest is deionized water; the anode is a high-purity nickel plate (not less than 99.9%), the pH of the solution is 5.5, the temperature is 60°C, and the cathode current density is 5mA / cm 2 , the electroplating time is 1.5 hours (the nickel tungsten rhenium obtained is as follows Figure 6 shown);

[0077] 3) Platinum electroplating: Place the test piece with nickel layer into platinum plating solution for electroplating; process parameters are: current density 0.5A / dm2 , pH value is 10.5 at 20℃ (adjusted with NaOH), the main salt of the plating solution is tetraammine platinum hydrogen ammonium phosphate (CAS127733-98-6), the electroplating temperature is 95℃, the anode is two high-purity platinum sheets (not less than 99.9%), and the concentration of platinum in the plating solution should not be less than 4g / L;

[0078] 4) Annealing homogenization: Take out the test piece with nickel and platinum layers, wash with deionized water, and dry. Then put it into a vacuum furnace for heat treatment at 1000℃ for 3 hours. The vacuum degree in the furnace is less than 2×10 -2 Pa, cooling with the furnace; the purpose of this step of vacuum annealing is mainly to obtain a coating with a tight bonding surface;

[0079] 5) Aluminizing: Aluminizing was carried out by embedding method. The aluminizing agent was 1.5% aluminum powder, 0.6% NaF, 0.2% KHF2, 0.1% NH4Cl, and the rest was Al2O3 powder. The temperature was 1050°C, the time was 4 hours, and the sample was cooled with the furnace.

[0080] In summary, the coating prepared in Example 3 needs to be subjected to a high-temperature cyclic oxidation test. The test temperature is 1100°C, and the single cycle time is 1 hour (50 minutes of heat preservation in the furnace, 10 minutes of cooling outside the furnace, and air cooling). After a certain number of cycles, the sample is weighed and the weight is recorded using a precision balance. The weight change is compared with the weight change of the coating without the diffusion barrier layer. Figure 7 shown.

[0081] It should be clear that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. The present invention is not limited to the specific steps and structures described above and shown in the figures. In addition, for the sake of brevity, a detailed description of known methods and technologies is omitted here.

[0082] The above are only embodiments of the present application and are not limited to the present application. For those skilled in the art, the present application may have various changes and variations without departing from the scope of the present invention. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A method for preparing a nickel-platinum-aluminum bonding layer having a nickel-tungsten-rhenium diffusion barrier coating, characterized in that: The method comprises the following steps: Electroplating nickel-tungsten-rhenium on the surface of the substrate to obtain a nickel-tungsten-rhenium layer; Platinum electroplating is performed on the nickel-tungsten-rhenium layer to obtain a platinum layer having a nickel-tungsten-rhenium diffusion barrier coating; The platinum layer is subjected to vacuum annealing treatment; The vacuum annealed platinum layer is subjected to aluminizing treatment to obtain a nickel-platinum-aluminum bonding layer having a nickel-tungsten-rhenium diffusion barrier coating; The nickel-tungsten-rhenium electroplating is performed on the surface of the substrate to obtain the nickel-tungsten-rhenium layer, specifically: Placing the substrate in an electroplating solution; wherein the electroplating solution is a mixed solution of nickel sulfate hexahydrate, sodium chloride, boron dioxide, sodium sulfate, potassium perrhenate, sodium tungstate dihydrate, citric acid and deionized water; The mass ratio of the components in the electroplating solution is: 6.72~8.78wt% of the nickel sulfate hexahydrate, 1.01~1.43wt% of the sodium chloride, 1.26~1.59wt% of the boron dioxide, 4.37~5.16wt% of the sodium sulfate, 0.67~1.19wt% of the potassium perrhenate, 0.84~1.35wt% of the sodium tungstate dihydrate, 1.01~1.11wt% of the citric acid, and the rest is the deionized water.

2. The method for preparing a nickel-platinum-aluminum bonding layer having a nickel-tungsten-rhenium diffusion barrier coating according to claim 1, characterized in that: The pH of the electroplating solution is 5-6.

3. The method for preparing a nickel-platinum-aluminum bonding layer having a nickel-tungsten-rhenium diffusion barrier coating according to claim 1, characterized in that: The anode is a high-purity nickel plate, and the cathode current density is 4~6mA / cm 2 , the deposition efficiency is 5~7µm / h.

4. The method for preparing a nickel-platinum-aluminum bonding layer having a nickel-tungsten-rhenium diffusion barrier coating according to any one of claims 1 to 3, characterized in that: The electroplating temperature is 60°C.

5. The method for preparing a nickel-platinum-aluminum bonding layer having a nickel-tungsten-rhenium diffusion barrier coating according to claim 1, characterized in that: Before the nickel-tungsten-rhenium electroplating is performed on the surface of the substrate to obtain the nickel-tungsten-rhenium layer, the method further includes: performing surface pretreatment on the substrate.

6. The method for preparing a nickel-platinum-aluminum bonding layer having a nickel-tungsten-rhenium diffusion barrier coating according to claim 1, characterized in that: The nickel-tungsten-rhenium layer is subjected to platinum electroplating to obtain a platinum layer having a nickel-tungsten-rhenium diffusion barrier coating, specifically: The nickel-tungsten-rhenium layer electroplated on the substrate is placed in a platinum plating solution for electrodeposition; wherein the anode is a high-purity platinum sheet and the current density of the cathode is 0.2-0.7A / dm 2 .

7. The method for preparing a nickel-platinum-aluminum bonding layer having a nickel-tungsten-rhenium diffusion barrier coating according to claim 1, characterized in that: The platinum layer is subjected to vacuum annealing treatment, specifically: The platinum layer electroplated on the nickel-tungsten-rhenium layer is cleaned and dried in sequence, and then placed in a vacuum furnace for heat treatment for a set time, and cooled along with the furnace.

8. The method for preparing a nickel-platinum-aluminum bonding layer having a nickel-tungsten-rhenium diffusion barrier coating according to claim 1, characterized in that: The platinum layer after vacuum annealing is subjected to aluminizing treatment, specifically: The platinum layer electroplated on the nickel-tungsten-rhenium layer is aluminized by an embedded aluminizing method; wherein the components of the aluminizing agent include aluminum powder, NaF, KHF2, NH4Cl and Al2O3 powder.

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