NiCrTa diffusion barrier layer, high-temperature protective coating and preparation method and application of NiCrTa diffusion barrier layer and high-temperature protective coating

Abstract

The invention discloses a NiCrTa diffusion impervious layer, a high-temperature protective coating and a preparation method and application of the NiCrTa diffusion impervious layer and the high-temperature protective coating. The NiCrTa diffusion barrier layer is a Ni-based metal coating with Cr and Ta solid solutions, and the chemical components of the NiCrTa diffusion barrier layer comprise 80 wt%-94.9 wt% of Ni, 5 wt%-15 wt% of Cr and 0.1 wt%-5 wt% of Ta. The high-temperature protective coating comprises a NiCrTa diffusion barrier layer and a NiAl bonding layer which are sequentially stacked on the surface of the high-temperature alloy matrix in the thickness direction of the high-temperature protective coating. The preparation method of the high-temperature protective coating comprises the step of sequentially depositing the NiCrTa diffusion barrier layer and the NiAl bonding layer on the surface of the high-temperature alloy matrix by adopting a magnetron sputtering technology to prepare the high-temperature protective coating. The NiCrTa diffusion impervious layer can regulate and control the phase balance of an alloy matrix, so that high-temperature alloy matrix structure degradation induced by diffusion phase transformation is effectively inhibited.

Description

Technical Field

[0001] This invention belongs to the field of high-temperature protective coatings, specifically relating to a NiCrTa diffusion barrier layer, a high-temperature protective coating, its preparation method, and its application. Background Technology

[0002] Aero engines, hailed as the "crown jewel of modern industry," are the core power units for large commercial aircraft and high-performance military aircraft. High-pressure turbine blades, as critical hot-end components of turbine engines, are typically made of austenitic nickel-based superalloys reinforced with second-phase particles. Harsh high-temperature operating conditions easily lead to alloy surface oxidation and microstructure degradation, posing a severe challenge to their long-term reliable operation. Thermal barrier coatings (TBCs) combined with film cooling technology can significantly increase the operating temperature of high-pressure turbine blades, greatly improving engine efficiency and service life. A TBC consists of an outer layer of low thermal conductivity Y-doped ZrO2 (YSZ) and an inner layer of MCrAlY (M: Ni and / or Co) metallic binder. Traditional MCrAlY binders can selectively oxidize to form a continuous, dense alumina layer, effectively blocking corrosion from high-temperature oxidizing atmospheres. However, because the alumina layer formed by MCrAlY grows relatively quickly, thermal stress accumulation can cause bending deformation at the binder interface, accelerating alumina layer fracture and failure, making it difficult to guarantee long-term stable operation of turbine blades under high-temperature oxidizing conditions.

[0003] Compared to traditional MCrAlY, NiAl coatings exhibit superior resistance to high-temperature oxidation. At 1100 ℃ (the highest service temperature of currently used high-temperature alloys), its oxidation rate constant... k p (approximately 1.9 × 10) -13 g 2 cm -4 s -1 ), compared to MCrAlY coating (approximately 2.9 × 10⁻⁶). -12 g 2 cm -4 s -1 The interdiffusion between the NiAl coating and the alloy matrix intensifies at temperatures exceeding 1000℃. In particular, the rapid diffusion of Al disrupts the original phase equilibrium of the alloy matrix, leading to the degradation of the γ′ (Ni3Al) strengthening phase and the precipitation of topologically close-packed phases (TCP). The γ′ phase is a strengthening phase in high-temperature alloys, and its dissolution significantly reduces the alloy's strength. The generated TCP is a brittle phase in high-temperature alloys, easily inducing stress concentration, promoting crack initiation and propagation, and accelerating alloy fatigue and creep failure. Therefore, suppressing the interdiffusion between the NiAl coating and the high-temperature alloy, and maintaining the microstructural stability of the high-temperature alloy matrix during long-term service, is crucial for ensuring the long-term reliable operation of turbine blades. Summary of the Invention

[0004] The main objective of this invention is to provide a NiCrTa diffusion barrier layer, a high-temperature protective coating, and their preparation methods and applications, so as to overcome the shortcomings of the prior art.

[0005] To achieve the aforementioned objectives, the technical solution adopted by this invention includes: The first aspect of the present invention provides a NiCrTa diffusion barrier layer comprising 80~94.9 wt.%Ni, 5~15 wt.%Cr and 0.1~5 wt.%Ta, wherein the NiCrTa diffusion barrier layer is a Ni-based metal coating of Cr and Ta solid solution.

[0006] A second aspect of the present invention provides a high-temperature protective coating comprising a NiCrTa diffusion barrier layer and a NiAl binder layer sequentially stacked on the surface of a high-temperature alloy substrate in its thickness direction.

[0007] A third aspect of the present invention provides a method for preparing the high-temperature protective coating, comprising: sequentially depositing a NiCrTa diffusion barrier layer and a NiAl binder layer on the surface of a high-temperature alloy substrate using magnetron sputtering technology to obtain the high-temperature protective coating.

[0008] A fourth aspect of the present invention provides the high-temperature protective coating in the field of high-temperature protection of substrates.

[0009] A fifth aspect of the present invention provides a high-temperature protective component comprising a high-temperature alloy substrate and a high-temperature protective coating deposited on the surface of the high-temperature alloy substrate.

[0010] A sixth aspect of the present invention provides a method for controlling phase balance to suppress microstructure degradation, comprising: depositing a high-temperature protective coating on the surface of a high-temperature alloy substrate, the high-temperature protective coating comprising a NiCrTa diffusion barrier layer and a NiAl binder layer sequentially stacked on the surface of the high-temperature alloy substrate in its thickness direction; At a high temperature of 900~1100℃, the NiCrTa diffusion barrier layer and the NiAl binder layer undergo a high-temperature interdiffusion phase transition reaction, thereby achieving phase balance regulation to inhibit tissue degradation.

[0011] Compared with the prior art, the present invention has at least the following beneficial effects: Unlike previous diffusion barrier layers that only focused on inhibiting element diffusion, the core function of the NiCrTa diffusion barrier layer in this invention is to regulate the phase equilibrium of the alloy matrix, thereby effectively suppressing the degradation of the high-temperature alloy matrix structure induced by diffusion phase transformation. Specifically, this coating utilizes the interaction of the chemical potentials of the diffusion elements; that is, Cr enhances the chemical potential of Al, inhibiting the rapid diffusion of Al into the alloy matrix and preventing the precipitation of the TCP brittle phase. At the same time, Ta undergoes a phase transformation reaction with Al to generate a γ′ single-phase transition layer, thereby inhibiting the degradation of the γ′ strengthening phase in the alloy matrix. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0013] Figure 1 This is a schematic cross-sectional view of a high-temperature alloy sample coated with a NiCrTa diffusion barrier layer and a NiAl binder layer according to the present invention. Figure 2 This is a cross-sectional microstructure diagram of a high-temperature alloy sample coated only with a NiAl bonding layer according to the present invention after 200 h of interdiffusion test at 1100℃. Figure 3 This is a cross-sectional microstructure diagram of a high-temperature alloy sample coated with a NiCrTa diffusion barrier layer and a NiAl binder layer after a 200-h, 1100℃ interdiffusion test. Detailed Implementation

[0014] In view of the problems existing in the prior art, the present invention provides a NiCrTa diffusion barrier layer, a high-temperature protective coating, a preparation method thereof, and its application. The NiCrTa diffusion barrier layer can effectively suppress the structural damage of the high-temperature alloy caused by interdiffusion between the NiAl binder layer and the high-temperature alloy matrix.

[0015] The following will provide a further explanation of the technical solution, its implementation process, and its principles.

[0016] The first aspect of the present invention provides a NiCrTa diffusion barrier layer comprising 80~94.9 wt.% Ni, 5~15 wt.% Cr and 0.1~5 wt.% Ta, wherein the NiCrTa diffusion barrier layer is a Ni-based metal coating with Cr and Ta solid solution.

[0017] In some embodiments, the NiCrTa diffusion barrier layer has a thickness of 2–50 μm. If the NiCrTa diffusion barrier layer is too thin, the protective effect of the coating will be reduced; if it is too thick, the cost will increase and it will exceed the component size design.

[0018] A second aspect of the present invention provides a high-temperature protective coating comprising a NiCrTa diffusion barrier layer and a NiAl binder layer sequentially stacked on the surface of a high-temperature alloy substrate in its thickness direction.

[0019] In some embodiments, at a high temperature of 900~1100 °C, the NiCrTa diffusion barrier layer and the NiAl binder layer can undergo a high-temperature interdiffusion reaction, i.e., Al + γ → γ′ (Ni3Al), forming a Ni3Al transition layer with Cr and Ta solid solutions. That is, the NiCrTa barrier layer provided by this invention can effectively suppress the precipitation of the brittle phase (TCP) of the topologically close-packed structure of the high-temperature alloy matrix and the dissolution of the Ni3Al (γ′) reinforcing phase during the interdiffusion process between the high-temperature alloy matrix and the NiAl protective coating.

[0020] In some embodiments, the thickness of the NiAl adhesive layer is 50~300 μm.

[0021] In some embodiments, the high-temperature alloy matrix is ​​a nickel-based high-temperature alloy matrix, which includes at least one of IN792, CMSX-4, DD6, etc., but is not limited to this.

[0022] In some implementations, the thickness of the Ni3Al transition layer is 10~300 μm.

[0023] The method for preparing the high-temperature protective coating provided in the third aspect of the present invention includes: processing the substrate with magnetron sputtering technology to sequentially deposit a NiCrTa diffusion barrier layer and a NiAl binder layer on the surface of a high-temperature alloy substrate to obtain a high-temperature protective coating.

[0024] In some implementation schemes, the method for manufacturing the high-temperature protective layer specifically includes: In <3×10 -3 The high-temperature alloy matrix is ​​heated to 200 ℃~400 ℃ in a vacuum chamber of Pa; Inert gas of 10-50 cm is introduced and the chamber pressure is adjusted to 0.5-1.0 Pa. The magnetron sputtering technology is used, with NiTa and Cr targets as cathode targets. Target currents are applied to the NiTa and Cr targets respectively, and a first bias voltage is applied to the high-temperature alloy substrate. The NiCrTa diffusion barrier layer is obtained by first deposition on the surface of the high-temperature alloy substrate. Then, a target current is applied to the NiAl target, a second bias voltage is applied to the NiCrTa diffusion barrier layer, and the NiAl binder layer is obtained by a second deposition on the surface of the NiCrTa diffusion barrier layer.

[0025] Furthermore, the process parameters for the magnetron sputtering technology used to deposit the NiCrTa diffusion barrier layer are as follows: the target current for the NiTa target is 0.1~0.5 A, and the sputtering power is 30~100 W; the target current applied to the Cr target is 0.01~0.10 A, and the sputtering power is 2~10 W; the first bias voltage is 70~150 V, and the first deposition time is 4~12 h.

[0026] Furthermore, the process parameters for the magnetron sputtering technology used to deposit the NiAl binder layer are as follows: the target current applied to the NiAl target is 0.1~0.8 A, the sputtering power is 80~200 W; the second bias voltage is 70~150 V, and the second deposition time is 12~24 h.

[0027] Furthermore, the inert gas includes, but is not limited to, argon.

[0028] In some embodiments, the preparation method further includes: pre-treating the surface of the high-temperature alloy substrate before the magnetron sputtering process, at least to remove surface impurities, wherein the pre-treatment includes sequentially grinding, ultrasonic cleaning and glow discharge cleaning of the surface of the high-temperature alloy substrate.

[0029] The application of the high-temperature protective coating provided in the fourth aspect of the present invention in the field of high-temperature protection of substrates.

[0030] A fifth aspect of the present invention provides a high-temperature protective component comprising a high-temperature alloy substrate and a high-temperature protective coating deposited on the surface of the high-temperature alloy substrate.

[0031] A sixth aspect of the present invention provides a method for controlling phase balance to suppress microstructure degradation, comprising: depositing a high-temperature protective coating on the surface of a high-temperature alloy substrate, the high-temperature protective coating comprising a NiCrTa diffusion barrier layer and a NiAl binder layer sequentially stacked on the surface of the high-temperature alloy substrate in its thickness direction; At a high temperature of 900~1100 ℃, the NiCrTa diffusion barrier layer and the NiAl binder layer undergo a high-temperature interdiffusion phase transition reaction, thereby achieving phase balance regulation to inhibit tissue degradation.

[0032] In summary, this invention proposes a NiCrTa diffusion barrier layer based on regional phase equilibrium design. This coating utilizes Cr to enhance the chemical potential of Al, preventing rapid Al diffusion; and utilizes Ta to stabilize the γ′ phase, inhibiting the degradation of the γ′ strengthening phase.

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Modifications or equivalent substitutions made by those skilled in the art based on their understanding of the technical solutions of this invention, without departing from the spirit and scope of the invention, should be covered within the protection scope of this invention.

[0034] Example 1 This embodiment provides a method for preparing a NiCrTa diffusion barrier layer and a high-temperature protective coating. The specific process is as follows: S1. Matrix pretreatment: The nickel-based superalloy IN792 matrix sample was polished sequentially with 400, 800 and 1200 grit sandpaper, and then ultrasonically cleaned with water and alcohol for 10 min to remove surface impurities.

[0035] S2. Vacuuming and Heating: The pretreated substrate sample is fixed onto the sample stage of the magnetron sputtering chamber using high-temperature conductive adhesive. NiTa and Cr targets are then mounted onto the two sputtering cathodes. The sputtering cathodes are tilted at 20°, and the target-to-substrate spacing is 8 cm in the vertical direction. The chamber is evacuated to 7 × 10⁻⁶ using a mechanical pump and a molecular pump. -4 Pa. Simultaneously, the sample stage is heated to 400°C.

[0036] S3. Glow Glow Cleaning: Introduce argon gas at a flow rate of 50 sccm. Adjust the chamber pressure to 2 Pa using the vacuum valve. Turn on the bias voltage and adjust it to 400 V (glow effect should occur), then perform glow glow argon ion etching for 30 minutes.

[0037] S4. Reduce the argon flow rate to 20 sccm, adjust the chamber pressure to 0.7 Pa, and adjust the bias voltage to 70 V. Turn on the DC power supplies for the NiTa and Cr targets, with target currents of 0.3 A and 0.05 A, and power of 60 W and 5 W, respectively. Deposit for 6 h to obtain the NiCrTa diffusion barrier layer on the IN792 substrate surface.

[0038] S5. Continue depositing a NiAl coating on the surface of the NiCrTa diffusion barrier layer. Deposition parameters: bottom vacuum of the chamber is 7 × 10⁻⁶. -4 A NiAl binder layer was prepared on the surface of the NiCrTa diffusion barrier layer under the following conditions: Pa, deposition temperature 400 °C, bias voltage 70 V, target current 0.5 A, sputtering power 100 W, and deposition time 24 h.

[0039] Following the above steps, a NiCrTa diffusion barrier layer and a NiAl binder layer are deposited on a nickel-based superalloy IN792 substrate, such as... Figure 1 As shown.

[0040] The NiCrTa diffusion barrier layer has a thickness of 5.6 μm, and the NiAl binder layer has a thickness of 54.5 μm. The NiCrTa diffusion barrier layer contains 89.4 wt.% Ni, 8.9 wt.% Cr, and 1.7 wt.% Ta.

[0041] Interdiffusion tests were conducted on high-temperature alloy samples coated with NiCrTa diffusion barrier layer and NiAl binder layer at 1100 °C for 200 h. The cross-sectional microstructure after the test is shown below. Figure 3 As shown, it can be seen that the NiCrTa diffusion barrier layer, the high-temperature alloy matrix and the NiAl binder layer undergo a high-temperature interdiffusion reaction to form Ni3Al (i.e., γ′ phase) with Cr and Ta solid solution.

[0042] Example 2 The method for preparing a NiCrTa diffusion barrier layer and a high-temperature protective coating provided in this embodiment differs from that in Example 1 in that: S4. Argon flow rate is 20 sccm, chamber pressure is adjusted to 0.7 Pa, and bias voltage is adjusted to 100 V. Turn on the DC power supply for NiTa and Cr targets, with target currents of 0.5 A and 0.1 A, and power of 100 W and 10 W, respectively. Deposition takes 4 h to obtain the NiCrTa diffusion barrier layer on the IN792 substrate surface.

[0043] Example 3 The method for preparing a NiCrTa diffusion barrier layer and high-temperature protective coating provided in this embodiment differs from that in Example 1 in that: S4. Argon flow rate is 20 sccm, chamber pressure is adjusted to 0.7 Pa, and bias voltage is adjusted to 150 V. The DC power supplies for NiTa and Cr targets are turned on, with target currents of 0.15 A and 0.02 A, and power of 30 W and 2 W, respectively. Deposition is carried out for 12 h to obtain the NiCrTa diffusion barrier layer on the IN792 substrate surface.

[0044] Example 4 The method for preparing a NiCrTa diffusion barrier layer and high-temperature protective coating provided in this embodiment differs from that in Example 1 in that: S5. Continue depositing a NiAl coating on the surface of the NiCrTa diffusion barrier layer. Deposition parameters: bottom vacuum of the chamber is 7 × 10⁻⁶. -4 A NiAl binder layer was prepared on the surface of the NiCrTa diffusion barrier layer under the following conditions: Pa, deposition temperature 400 °C, bias voltage 100 V, target current 0.8 A, sputtering power 200 W, and deposition time 12 h.

[0045] Example 5 The method for preparing a NiCrTa diffusion barrier layer and high-temperature protective coating provided in this embodiment differs from that in Example 1 in that: S5. Continue depositing a NiAl coating on the surface of the NiCrTa diffusion barrier layer. Deposition parameters: bottom vacuum of the chamber is 7 × 10⁻⁶. -4 A NiAl binder layer was prepared on the surface of the NiCrTa diffusion barrier layer under the following conditions: Pa, deposition temperature 400 °C, bias voltage 150 V, target current 0.4 A, sputtering power 80 W, and deposition time 24 h.

[0046] Comparative Example 1 In this comparative example, the preparation process of the NiAl binder layer is the same as in Example 1, except that the NiCrTa diffusion barrier layer is not prepared.

[0047] Performance testing The samples prepared in Example 1 and Comparative Example 1 were placed in a muffle furnace and heated to 1100 °C for high-temperature interdiffusion testing.

[0048] The tested samples were prepared using metallographic techniques, and their cross-sectional microstructure was observed under a scanning electron microscope. The microstructure of the cross-section of the high-temperature alloy sample coated only with a NiAl binder layer after testing is shown below. Figure 2 As shown, the cross-sectional microstructure of the high-temperature alloy sample coated with a NiCrTa diffusion barrier layer and a NiAl binder layer after testing is as follows: Figure 3 As shown in the figure, the results indicate that the uncoated NiCrTa barrier layer underwent severe interdiffusion, resulting in the precipitation of a large amount of TCP brittle phase and the dissolution of the γ' reinforcing phase; the sample coated with the NiCrTa barrier layer also underwent diffusion, forming a γ' phase transition layer at the interface, without the precipitation of TCP brittle phase.

[0049] All aspects, embodiments, features, and examples of this invention should be considered illustrative in all respects and are not intended to limit the invention; the scope of the invention is defined only by the claims. Other embodiments, modifications, and uses will become apparent to those skilled in the art without departing from the spirit and scope of the invention.

[0050] Although the invention has been described with reference to illustrative embodiments, those skilled in the art will understand that various other changes, omissions, and / or additions can be made without departing from the spirit and scope of the invention, and that elements of the embodiments can be substituted with substantially equivalents. Furthermore, many modifications can be made without departing from the scope of the invention to adapt particular situations or materials to the teachings of the invention. Therefore, this invention is not intended to be limited to the specific embodiments disclosed for carrying out the invention, but rather is intended to encompass all embodiments falling within the scope of the appended claims. Moreover, unless specifically stated otherwise, any use of the terms first, second, etc., does not indicate any order or importance, but is used to distinguish one element from another.

Claims

1. A NiCrTa diffusion barrier layer, characterized in that, include: 80~94.9 wt% Ni, 5~15 wt% Cr and 0.1~5 wt% Ta, wherein the NiCrTa diffusion barrier layer is a Ni-based metal coating with Cr and Ta solid solution.

2. The NiCrTa diffusion barrier layer according to claim 1, characterized in that: The thickness of the NiCrTa diffusion barrier layer is 2~50 μm.

3. A high-temperature protective coating, characterized in that, It includes the NiCrTa diffusion barrier layer and NiAl binder layer as described in claim 1 or 2, which are sequentially stacked on the surface of a high-temperature alloy substrate in the thickness direction.

4. The high-temperature protective coating according to claim 3, characterized in that: At high temperatures of 900~1100 ℃, the NiCrTa diffusion barrier layer and the NiAl binder layer can undergo a high-temperature interdiffusion phase transition reaction to form a Ni3Al transition layer with Cr and Ta solid solutions.

5. The high-temperature protective coating according to claim 4, characterized in that: The thickness of the NiAl bonding layer is 50~300 μm; And / or, the high-temperature alloy matrix is ​​a nickel-based high-temperature alloy matrix, and the high-temperature alloy matrix includes at least one of IN792, CMSX-4, and DD6; And / or, the thickness of the Ni3Al transition layer is 2~300 μm.

6. The method for preparing the high-temperature protective coating according to any one of claims 3 to 5, characterized in that, include: A high-temperature protective coating was prepared by sequentially depositing a NiCrTa diffusion barrier layer and a NiAl binder layer on the surface of a high-temperature alloy substrate using magnetron sputtering technology.

7. The preparation method according to claim 6, characterized in that, Specifically, it includes: In <3×10 -3 The high-temperature alloy matrix is ​​heated to 200 ℃~400 ℃ in a vacuum chamber of Pa; Inert gas at a pressure of 10–50 sccm is introduced and the chamber pressure is adjusted to 0.5–1.0 Pa. Using the magnetron sputtering technology, NiTa and Cr targets are used as cathode targets, and inert gas is used as the working gas. Target currents are applied to the NiTa and Cr targets respectively, and a first bias voltage is applied to the high-temperature alloy substrate. A NiCrTa diffusion barrier layer is deposited on the surface of the high-temperature alloy substrate through a first deposition process. The process parameters for depositing the NiCrTa diffusion barrier layer are as follows: target current applied to the NiTa target is 0.1–0.5 A, sputtering power is 30–100 W; target current applied to the Cr target is 0.01–0.10 A, sputtering power is 2–10 W; the first bias voltage is 70–150 V; and the first deposition time is 4–12 h. A target current is then applied to the NiAl target, and a second bias voltage is applied to the NiCrTa diffusion barrier layer. The NiAl binder layer is then deposited on the surface of the NiCrTa diffusion barrier layer via a second deposition process. The process parameters for the magnetron sputtering technique used to deposit the NiAl binder layer are as follows: the target current applied to the NiAl target is 0.1–0.8 A, the sputtering power is 80–200 W, the second bias voltage is 70–150 V, and the second deposition time is 12–24 h. And / or, the preparation method further includes: pre-treating the surface of the high-temperature alloy substrate before the magnetron sputtering process, at least to remove surface impurities, wherein the pre-treatment includes sequentially grinding, ultrasonic cleaning and glow discharge cleaning of the surface of the high-temperature alloy substrate.

8. The application of the high-temperature protective coating according to any one of claims 3 to 5 in the field of high-temperature protection of substrates.

9. A high-temperature protective component, characterized in that, It includes a high-temperature alloy substrate and a high-temperature protective coating as described in any one of claims 3 to 5 deposited on the surface of the high-temperature alloy substrate.

10. A method for regulating phase balance to inhibit tissue degradation, characterized in that, include: A high-temperature protective coating according to any one of claims 3 to 5 is deposited on the surface of a high-temperature alloy substrate, wherein the high-temperature protective coating comprises a NiCrTa diffusion barrier layer and a NiAl bonding layer as described in claim 1 or 2, which are sequentially stacked on the surface of the high-temperature alloy substrate in the thickness direction; At a high temperature of 900~1100℃, the NiCrTa diffusion barrier layer and the NiAl binder layer undergo a high-temperature interdiffusion phase transition reaction, thereby achieving phase balance regulation to inhibit tissue degradation.

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