A multilayer coating structure comprising a ceramic barrier layer and a method for producing the same

Abstract

The application provides a preparation method of a multilayer coating structure containing a ceramic barrier layer. Compared with the prior art, the thermally grown oxide layer prepared by the application is an alpha-Al2O3 film layer, has a dense hexagonal close-packed (hcp) crystal structure, a low diffusion coefficient, no obvious defects, good high-temperature stability (not prone to phase change), and can effectively prevent element interdiffusion between metal layers; meanwhile, small-size through micro-holes are formed in the thermally grown oxide layer through dielectric barrier discharge and are dispersedly distributed, which can release the stress in the oxide layer on one hand and make the metal coating directly contact the metal bonding layer through the through micro-holes and locally diffuse elements on the other hand, forms a pinning effect, and improves the bonding force of the coating.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of coating, and particularly relates to a multilayer coating structure containing a ceramic barrier layer and a preparation method thereof. BACKGROUND

[0002] With the rapid development of aerospace industry, the multifunctional requirements of high-temperature alloy surface coating are higher and higher. In order to meet the various performance requirements of the coating, a multilayer coating structure emerges as the times require, and a common structure is that the coating system contains various metal coatings to meet different performance requirements. However, under high temperature, the diffusion rate of metal elements between different coatings will greatly increase, which will cause the composition of each layer to change significantly, and finally lead to the failure of the coating structure. Therefore, preparing an effective metal element diffusion barrier layer is a key link in the preparation process of such coating.

[0003] Since the diffusion coefficient between ceramic material and metal material is relatively low, a ceramic layer with a certain thickness can be prepared between metal coatings as a barrier layer, which can effectively inhibit the element interdiffusion between different metal layers under high temperature, and further ensure the stability of the overall structure and performance of the coating. However, the thermal expansion coefficients of ceramic and metal do not match, which will lead to poor adhesion at the interface between the ceramic layer and the metal layer, and the coating is prone to peeling, cracking and other phenomena during use. Therefore, necessary measures need to be taken to improve the adhesion of the coating interface, so as to improve the service life of the coating. SUMMARY

[0004] Therefore, the technical problem to be solved by the present application is to provide a multilayer coating structure containing a ceramic barrier layer and a preparation method thereof, which has excellent and stable comprehensive performance.

[0005] The present application provides a preparation method of a multilayer coating structure containing a ceramic barrier layer, comprising the following steps:

[0006] S1) preparing a metal bonding layer: forming a metal bonding layer on the surface of an alloy substrate;

[0007] S2) generating a thermal growth oxide layer: performing high-temperature oxidation treatment on the metal bonding layer to generate a thermal growth oxide layer;

[0008] S3) generating through micropores by dielectric barrier discharge: treating the thermal growth oxide layer by dielectric barrier discharge to form through micropores on the surface of the thermal growth oxide layer, and exposing the metal bonding layer at the bottom of the micropores;

[0009] S4) preparing a metal coating: forming a metal coating on the surface of the thermal growth oxide layer with through micropores;

[0010] S5) high-temperature vacuum treatment to obtain a multilayer coating structure containing a ceramic barrier layer.

[0011] Preferably, the alloy matrix is ​​selected from nickel-based alloys;

[0012] The metal bonding layer is selected from MCrAlX coating, wherein M is selected from Ni and / or Co; X is selected from one or more of Y, Si and Hf; the mass content of Al element in the metal bonding layer is 7% to 20%; and the thickness of the metal bonding layer is 25 to 50 μm.

[0013] Preferably, the temperature of the high-temperature oxidation treatment in step S2) is 950℃~1100℃; and the time of the high-temperature oxidation treatment is 30~35h.

[0014] Preferably, in step S3), the voltage of the dielectric barrier discharge is 200–1200V, the frequency is 25–40kHz, and the processing time is 10–60min.

[0015] Preferably, the thickness of the metal coating in step S4) is 0.5 to 10 μm.

[0016] Preferably, in step S4), a metal coating is formed on the surface of the thermally grown oxide layer that forms through micropores by physical vapor deposition;

[0017] The physical vapor deposition is selected from magnetron sputtering or arc deposition;

[0018] The base vacuum level of the magnetron sputtering is 3×10⁻⁶. -3 ~5×10 -3 Pa; the working gas pressure of the magnetron sputtering is 5 × 10 Pa; -2 ~8×10 -1 Pa; the power of the magnetron sputtering is 2.5 to 4.5 W; the target-substrate distance of the magnetron sputtering is 10 to 15 cm;

[0019] The arc current of the arc deposition is 60–180 A; the target-substrate distance of the arc deposition is 10–15 cm.

[0020] Preferably, the temperature of the high-temperature vacuum treatment in step S5) is 600℃~800℃; the time of the high-temperature vacuum treatment is 30~100h.

[0021] The present invention also provides a multilayer coating structure containing a ceramic barrier layer, comprising:

[0022] Alloy matrix;

[0023] A metal bonding layer disposed on the surface of the alloy substrate;

[0024] A ceramic barrier layer is disposed on the surface of the metal bonding layer; the ceramic barrier layer includes a thermally grown oxide layer and through-holes disposed in the grown oxide layer.

[0025] A metal coating is arranged on the surface of the thermally grown oxide layer, and the metal coating is in contact with the metal bonding layer through the through micro-holes.

[0026] Preferably, the diameter of the through micro-holes is 20-180 μm, and the area ratio of the through micro-holes in the ceramic barrier layer is 0.5%-1.5%.

[0027] Preferably, the thickness of the thermally grown oxide layer is 1-5 μm.

[0028] The application provides a preparation method of a multilayer coating structure with a ceramic barrier layer, which comprises the following steps: S1) preparing a metal bonding layer: forming a metal bonding layer on the surface of an alloy substrate; S2) generating a thermally grown oxide layer: performing high-temperature oxidation treatment on the metal bonding layer to generate a thermally grown oxide layer; S3) generating through micro-holes by dielectric barrier discharge: performing treatment on the thermally grown oxide layer by dielectric barrier discharge to form through micro-holes on the surface of the thermally grown oxide layer, and exposing the metal bonding layer at the bottom of the micro-holes; S4) preparing a metal coating: forming a metal coating on the surface of the thermally grown oxide layer with the through micro-holes; and S5) high-temperature vacuum treatment, to obtain a multilayer coating structure with a ceramic barrier layer.

[0029] Compared with the prior art, the thermally grown oxide layer prepared by the application is an α-Al2O3 film layer, has a dense hcp (hexagonal close-packed) crystal structure, has a low diffusion coefficient, has no obvious defects, has good high-temperature stability (is not prone to phase change), and can effectively prevent the interdiffusion of elements between metal layers; meanwhile, the small-size through micro-holes are dispersedly distributed in the thermally grown oxide layer by dielectric barrier discharge, which can release the stress in the oxide layer on one hand, and make the metal coating directly contact with the metal bonding layer through the through micro-holes and locally diffuse elements on the other hand, to form a pinning effect and improve the bonding force of the coating. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 The figure is a preparation flowchart of the multilayer coating structure provided by the application;

[0031] Figure 2 The figure is a micro-morphology diagram (scanning electron microscope diagram) of the through micro-holes formed in Examples 1-3 of the application;

[0032] Figure 3 The figure is an energy spectrum diagram of the central area of the through micro-holes formed in Example 2 of the application. DETAILED DESCRIPTION

[0033] With reference to the drawings, the technical solutions in the embodiments of the present application will be clearly and completely described in order to make the present application apparent to those skilled in the art. Obviously, the described embodiments are only a part but not all of the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall into the protection scope of the present application.

[0034] The present application provides a preparation method of multilayer coating structure containing ceramic barrier layer, comprising the following steps: S1) preparing metal adhesive layer: forming metal adhesive layer on the surface of alloy substrate; S2) generating thermal growth oxide layer: generating thermal growth oxide layer by high temperature oxidation treatment on the metal adhesive layer; S3) generating through micropores by dielectric barrier discharge: treating the thermal growth oxide layer by dielectric barrier discharge to form through micropores on the surface of the thermal growth oxide layer, and exposing the metal adhesive layer at the bottom of the micropores; S4) preparing metal coating: forming metal coating on the surface of the thermal growth oxide layer with through micropores; S5) high temperature vacuum treatment, obtaining multilayer coating structure containing ceramic barrier layer.

[0035] Referring to Figure 1 , Figure 1 The preparation flowchart of multilayer coating structure containing ceramic barrier layer provided by the present application is shown.

[0036] Among them, the present application does not have special restrictions on the source of all raw materials, which can be purchased in the market.

[0037] (1) preparing metal adhesive layer

[0038] Forming metal adhesive layer on the surface of alloy substrate, such as Figure 1In (a) shown, wherein 1 is the alloy matrix, 2 is the metal bonding layer. The alloy matrix can be any alloy matrix known to those skilled in the art, and is not particularly limited, and in the present application, preferably is a high-temperature alloy, more preferably a nickel-based high-temperature alloy; the nickel-based high-temperature alloy is a high-temperature alloy with nickel as the matrix (content generally greater than 50%) and having relatively high strength and good oxidation resistance and combustion gas corrosion resistance in the range of 650℃-1000℃, and is well known to those skilled in the art; in some embodiments provided in the present application, the alloy matrix can specifically be DZ417G; in the present application, the surface of the alloy matrix is preferably first subjected to surface treatment and activation, and then a metal coating layer is formed; the method of surface treatment and activation can be any method known to those skilled in the art, and is not particularly limited, and in the present application, preferably the surface of the alloy matrix is subjected to surface treatment and activation according to GB 1373-1983 “General Rules for Surface Pretreatment of Hot Sprayed Metal Parts”; the method of forming the metal bonding layer can be any method known to those skilled in the art, and is not particularly limited, and in the present application, preferably a physical vapor deposition (PVD) process is used to form the metal bonding layer on the surface of the alloy matrix; the physical vapor deposition process is further preferably magnetron sputtering or arc deposition; the base vacuum degree of the magnetron sputtering is preferably 3×10 -3 ~5×10 -3 Pa; the working gas pressure of the magnetron sputtering is preferably 7×10 -2 ~8×10 -1Pa; the power of the magnetron sputtering is preferably 2.5-4.5 W; the target-substrate distance of the magnetron sputtering is 10-15 cm; the arc current of the arc deposition is preferably 60-180 A, more preferably 60-160 A, even more preferably 60-120 A, and most preferably 80-100 A; the target-substrate distance of the arc deposition is 10-15 cm; the metal bonding layer is preferably a MCrAlX coating, wherein M is preferably Ni and / or Co, more preferably Ni; X is preferably one or more of Y, Si and Hf, more preferably Y and / or Si; the mass content of Al in the metal bonding layer is 7%-20%, more preferably 7%-15%, even more preferably 7%-12%, and most preferably 7%-10%; the mass content of Cr in the metal bonding layer is preferably 10%-30%, more preferably 15%-25%, even more preferably 18%-22%, and most preferably 20%; the mass content of X in the metal bonding layer is preferably 0.1%-1%, more preferably 0.2%-0.7%, and even more preferably 0.3%-0.7%; in a further specific embodiment, X is Y and Si, the mass content of Y in the metal bonding layer is preferably 0.1%-0.5%, more preferably 0.1%-0.3%, and even more preferably 0.2%; the mass content of Si in the metal bonding layer is preferably 0.1%-0.5%, more preferably 0.2%-0.4%, and even more preferably 0.3%; in a specific embodiment, the metal bonding layer is preferably Ni-20Cr-10Al-0.2Y-0.3Si; the thickness of the metal bonding layer is 25-50 μm; in a specific embodiment, the thickness of the metal bonding layer is 25-30 μm, 35-40 μm or 45-50 μm; in the present application, the metal bonding layer is preferably subjected to vacuum heat treatment after formation, so as to enhance the bonding force between the metal bonding layer and the alloy substrate and eliminate the internal stress of the metal bonding layer; the temperature of the vacuum heat treatment is preferably 600-900 °C, more preferably 700-900 °C, even more preferably 800-900 °C, and most preferably 850-870 °C; the time of the vacuum heat treatment is preferably 1-5 h, more preferably 2-4 h, and even more preferably 3 h.

[0039] (2) generating a thermal growth oxide layer

[0040] generating a thermal growth oxide layer on the surface of the metal bonding layer, such as Figure 1As shown in (b), 1 is the alloy substrate, 2 is the metal bonding layer, and 3 is the thermally grown oxide layer. When certain metals or alloys are exposed to a high-temperature, oxygen-rich environment for a certain period, an oxide film will appear on their surface, commonly called thermally grown oxide (TGO). This invention utilizes this phenomenon to perform high-temperature oxidation treatment on the metal bonding layer (containing sufficient Al elements). By controlling the temperature and time of the high-temperature oxidation treatment, a certain thickness, dense, uniform, and singular α-Al₂O₃ film layer, i.e., the thermally grown oxide layer, is generated on its surface. This oxide layer can play a significant role in inhibiting diffusion, ensuring the stability of the performance of each metal layer. Specifically, the process is as follows: The metal bonding layer is subjected to high-temperature oxidation treatment to generate the thermally grown oxide layer, that is, after forming the metal bonding layer on the surface of the alloy substrate, high-temperature oxidation treatment is performed to generate the thermally grown oxide layer; the high-temperature oxidation treatment... The preferred temperature is 950℃~1100℃, more preferably 1000℃~1050℃; the preferred time for the high-temperature oxidation treatment is 30~35h; in this invention, a thermally grown oxide layer of appropriate thickness, dense and uniform α-Al2O3 film layer can be confirmed by scanning electron microscopy (SEM), photoexcited fluorescence spectroscopy (PSLS) and other detection techniques to achieve the blocking effect; the preferred thickness of the thermally grown oxide layer is 1~5μm, more preferably 2~4μm; in some embodiments provided by this invention, the thickness of the thermally grown oxide layer is specifically 2~3μm or 3~4μm.

[0041] (3) Using dielectric barrier discharge to generate through-hole micropores

[0042] The thermally grown oxide layer is treated using dielectric barrier discharge to form through-holes in the oxide layer, exposing a portion of the metal adhesive layer surface at the bottom of the micropores. Figure 1 As shown in (c), 1 is the alloy substrate, 2 is the metal bonding layer, 3 is the thermally grown oxide layer, and 4 is the through-hole micropore. Dielectric barrier discharge is a discharge phenomenon when a conductor surface has an insulating dielectric. By appropriately increasing the discharge voltage and adjusting the ambient atmosphere, the discharge can break down the insulating dielectric without causing large-area damage. This invention utilizes the dielectric barrier discharge effect to form diffusely distributed small-sized through-hole micropores on the surface of the thermally grown oxide layer, exposing the metal layer at the bottom of the hole. The dielectric barrier discharge voltage is preferably 200–1200V, more preferably 400–1200V. In some embodiments provided by this invention, the dielectric barrier discharge voltage is specifically 400V, 600V, and 1200V. The dielectric barrier discharge frequency is preferably 25–40kHz, more preferably 30–40kHz. The dielectric barrier discharge is preferably carried out in a protective atmosphere. The protective atmosphere can be any protective atmosphere known to those skilled in the art and is not particularly limited. In this invention, argon is preferred. The dielectric barrier discharge pressure is preferably 7 × 10⁻⁶.-2 ~8x10 -1 Pa; in some embodiments provided by the present application, the gas pressure of the dielectric barrier discharge is specifically 9x10 -2 ~4.2x10 -1 Pa or 4.5x10 -1 ~5.2x10 -1 Pa; the pulse voltage duty cycle of the dielectric barrier discharge is preferably 30% to 50%, more preferably 40%; the processing time of the dielectric barrier discharge is preferably 10 to 60 min, more preferably 10 to 50 min, more preferably 10 to 40 min, more preferably 10 to 30 min, more preferably 10 to 20 min, and most preferably 10 to 15 min. In the present application, the size and number of the through micro-holes can be flexibly adjusted by adjusting the voltage and time during sputtering cleaning. The longer the processing time of the dielectric barrier discharge, the more the number of the through micro-holes grown. The present application utilizes the principle of dielectric barrier discharge to gather a large amount of energy in a small size range at certain positions of the thermal growth oxide layer, resulting in explosive electron emission (discharge) and forming a large number of small-size through micro-holes dispersedly distributed on the surface of the thermal growth oxide layer, so as to expose the local metal bonding layer at the bottom of the micro-holes. On the one hand, the through holes play a role in releasing the internal stress of the oxidation film (ceramic barrier layer); on the other hand, the metal layers on both sides of the oxide layer can be directly contacted and locally element interdiffusion through the through holes, forming a pinning effect, thereby improving the adhesion between the coatings; and the through micro-holes on the surface of the thermal growth oxide layer are dispersedly and uniformly distributed in a lattice shape, with small size and small area proportion, so that the element diffusion at the through micro-holes does not affect the barrier effect of the overall thermal growth oxide layer.

[0043] (4) preparing a metal coating

[0044] A metal coating is formed on the surface of the thermal growth oxide layer with through micro-holes. In this process, the metal coating also fills the through micro-holes to form a pinning structure in contact with the alloy matrix. The present application does not have special limitations on the method for forming the metal coating, which can be formed according to the methods well known to those skilled in the art. In the present application, the metal coating can be formed on the surface of the thermal growth oxide layer with through micro-holes by physical vapor deposition; the physical vapor deposition is preferably magnetron sputtering or arc deposition; the base vacuum degree of the magnetron sputtering is preferably 3x10 -3 ~5x10 -3 Pa, more preferably 4x10 -3 ~5x10 -3 Pa; the working gas pressure of the magnetron sputtering is preferably 5x10 -2 ~8x10 -1 Pa, more preferably 7x10 -2 ~8x10 -1 Pa, more preferably 5x10-1 ~ 8 x 10 -1 Pa, most preferably 6.5 x 10 -1 ~ 7.5 x 10 -1 Pa; the power of the magnetron sputtering is preferably 2.5 ~ 4.5 W; the target-substrate distance of the magnetron sputtering (the distance between the sputtering palladium and the surface where the thermally grown oxide layer generating the through micro-pores is located) is preferably 10 ~ 15 cm, more preferably 10 ~ 12 cm; the body vacuum of the arc deposition is preferably 3 x 10 -3 ~ 5 x 10 -3 Pa, more preferably 4 x 10 -3 ~ 5 x 10 -3 Pa; the deposition pressure of the arc deposition is preferably 5 x 10 -2 ~ 8 x 10 -1 Pa, more preferably 5 x 10 -2 ~ 7.3 x 10 -1 Pa; the arc current of the arc deposition is preferably 50 ~ 180 A; the target-substrate distance of the arc deposition is preferably 10 ~ 15 cm; the thickness of the metal coating formed is preferably 0.5 ~ 10 μm.

[0045] (5) high-temperature vacuum treatment

[0046] After the metal coating is formed, high-temperature vacuum treatment is performed, thereby obtaining a multilayer coating structure containing a ceramic barrier layer. The high-temperature vacuum treatment can further strengthen the bonding of the metal on both sides of the thermally grown oxide layer at the through pores, as shown in Fig. 1 (d), wherein 1 is the alloy substrate, 2 is the metal bonding layer, 3 is the thermally grown oxide layer, 4 is the through micro-pore, 5 is the metal coating, and 6 is the pinning structure at the through micro-pore site; the temperature of the high-temperature vacuum treatment is preferably 600 °C ~ 800 °C, more preferably 600 °C ~ 700 °C; the time of the high-temperature vacuum treatment is preferably 30 ~ 100 h, more preferably 50 ~ 100 h, and more preferably 80 ~ 100 h. Figure 1 The thermally grown oxide layer prepared in the present application is an α-Al2O3 film layer having a dense hcp (hexagonal close-packed) crystal structure, low diffusion coefficient, no obvious defects, and good high-temperature stability (not easy to undergo phase transition), which can effectively prevent the mutual diffusion of elements between the metal layers; at the same time, the small-size through micro-pores are dispersedly distributed in the thermally grown oxide layer by dielectric barrier discharge, which can release the stress in the oxide layer on one hand and make the metal coating directly contact with the alloy substrate through the through micro-pores and locally diffuse elements, thereby forming a pinning effect and improving the bonding force between the coating layers.

[0047] The present application also provides a multilayer coating structure containing a ceramic barrier layer, comprising:

[0048]

[0049] ​an alloy substrate;

[0050] a metal bond layer disposed on the surface of the alloy substrate;

[0051] a ceramic barrier layer disposed on the surface of the metal bond layer; the ceramic barrier layer comprises a thermal growth oxide layer and through micropores disposed in the thermal growth oxide layer;

[0052] a metal coating layer disposed on the surface of the thermal growth oxide layer, and the metal coating layer is in contact with the metal bond layer through the through micropores.

[0053] The alloy substrate can be any alloy substrate known to those skilled in the art, and is not particularly limited, and in the present application, it is preferably a high-temperature alloy, and more preferably a nickel-based high-temperature alloy; the nickel-based high-temperature alloy is a high-temperature alloy known to those skilled in the art, which has a nickel matrix (generally greater than 50%) and has high strength and good oxidation resistance and gas corrosion resistance at 650-1000°C; in some embodiments provided by the present application, the alloy substrate can be DZ417G.

[0054] The surface of the alloy substrate is provided with a metal bond layer; the metal bond layer is preferably an MCrAlX coating layer, wherein M is preferably Ni and / or Co, and more preferably Ni; X is preferably one or more of Y, Si and Hf, and more preferably Y and / or Si; the mass content of Al in the metal bond layer is 7%-20%, more preferably 7%-15%, more preferably 7%-12%, and most preferably 7%-10%; the mass content of Cr in the metal bond layer is preferably 10%-30%, more preferably 15%-25%, more preferably 18%-22%, and most preferably 20%; the mass content of X in the metal bond layer is preferably 0.1%-1%, more preferably 0.2%-0.7%, and more preferably 0.3%-0.7%; further specifically, X is Y and Si, the mass content of Y in the metal bond layer is preferably 0.1%-0.5%, more preferably 0.1%-0.3%, and more preferably 0.2%; the mass content of Si in the metal bond layer is preferably 0.1%-0.5%, more preferably 0.2%-0.4%, and more preferably 0.3%; in one specific embodiment provided by the present application, the metal bond layer is preferably specifically Ni-20Cr-10Al-0.2Y-0.3Si; the thickness of the metal bond layer is 25-50 μm.

[0055] The surface of the metal bonding layer is provided with a ceramic barrier layer; the ceramic barrier layer comprises a thermal growth oxide layer and through micro-holes provided in the growth oxide layer; the thermal growth oxide layer is preferably obtained by high-temperature oxidation treatment on the metal bonding layer; the thickness of the thermal growth oxide layer is preferably 1-5 μm, and more preferably 2-4 μm; the diameter of the through micro-holes is preferably 20-180 μm; in some embodiments provided in the application, the diameter of the through micro-holes is specifically 20-50 μm, 60-70 μm or 160-180 μm; the area ratio of the through micro-holes contained in the ceramic barrier layer is preferably 0.5%-1.5%, that is, the total area of the through micro-holes is 0.5%-1.5% of the area of the ceramic barrier layer; the diameter of the through micro-holes and the area ratio in the ceramic barrier layer can be selected according to the type and / or thickness of the metal coating, and have very wide applicability (large process margin) for different metal coating materials, and can ensure that different metal coating materials can obtain stable performance and excellent bonding force through the method.

[0056] The multilayer coating structure provided in the application effectively blocks the element interdiffusion between the metal layers by the oxide ceramic layer, and produces through micro-holes in the barrier layer by the dielectric barrier discharge method, plays a pinning effect on the metal coating, releases the stress in the ceramic layer, improves the bonding force of the coating, and thus obtains a multilayer coating structure with excellent and stable comprehensive performance.

[0057] In order to further illustrate the application, the application provides a multilayer coating structure and a preparation method thereof, which are described in detail below in combination with examples.

[0058] The reagents used in the following examples are all commercially available.

[0059] Example 1

[0060] (1) A Ni-20Cr-10Al-0.2Y-0.3Si metal bonding layer is prepared on a substrate sample of nickel-based high-temperature alloy DZ417G by cathodic arc deposition, and the thickness is 25-30 μm (see FIG. 1). Figure 1 a) The process is as follows: the surface of the DZ417G alloy substrate is treated and activated according to GB Ⅱ 37 3-1983 "General rules for surface pretreatment of thermal sprayed metal parts", the arc current is 80-100 A, and vacuum treatment is performed at 870 ℃ for 3 h after deposition.

[0061] (2) The sample with the prepared bonding layer is placed in a 1050 ℃ high-temperature muffle furnace for oxidation for 30 h, and a single α-Al2O3 film layer is obtained (see FIG. 2). Figure 1 b) (which can be confirmed by photo-stimulated luminescence spectrum technology (PSLS) and scanning electron microscopy (SEM)), and the thickness is 2-3 μm.

[0062] (3) Put the sample from step (2) into a thin film deposition process chamber, first introduce proper Ar to make the pressure in the vacuum chamber 9 x 10 -2 ~ 4.2 x 10 -1 Pa. Apply a pulsed bias voltage of 400 V, 30-40 kHz, and 40% duty cycle to the sample turntable. Perform bombardment cleaning, and the sample surface will generate dielectric barrier discharge for 10 min (the longer the time, the more the number of through micro-holes) (see Figure 1 c). The sample surface will generate micro-holes with a diameter of φ 20-50 μm, as shown in Figure 2 a.

[0063] (4) After the process in step (3) is completed, deposit a Ta metal coating on the sample surface by magnetron sputtering (cathodic arc deposition is also applicable), and the deposition thickness is usually 3-5 μm. The deposition process is as follows: base vacuum 5 x 10 -3 Pa, sputtering pressure 6.5-7.5 x 10 -1 Pa, sputtering power 2.5-3.5 W, and target-to-substrate distance 10-12 cm.

[0064] (5) Put the sample with the deposited film from step (4) into a vacuum furnace for heat treatment at 600°C for 100 h to further stabilize the coating structure (see Figure 1 d).

[0065] (6) Verify the barrier effect of the ceramic barrier layer and the stability of the coating structure by a high-temperature oxidation test method. After constant temperature oxidation at 900°C for 500 h, no peeling, cracking, or wrinkling of the coating occurs. Test the surface composition of the coating by an energy-dispersive spectrometer, and no alloy elements such as Ni and Cr from the metal bonding layer and the substrate under the ceramic barrier layer appear, which indicates that the ceramic layer effectively blocks the diffusion of the elements and has excellent barrier performance.

[0066] Example 2

[0067] (1) Prepare a Ni-20Cr-10Al-0.2Y-0.3Si metal bonding layer on a substrate sample of nickel-based superalloy DZ417G by cathodic arc process, and the thickness is 35-40 μm (see Figure 1 a). The process is as follows: perform surface treatment and activation on the DZ417G alloy substrate according to GB Ⅱ 373-1983 "General Rules for Surface Pretreatment of Thermally Sprayed Metal Parts", and perform high-temperature vacuum heat treatment at 870°C for 3 h after deposition.

[0068] (2) Put the sample with the prepared bonding layer into a 1050°C high-temperature muffle furnace for oxidation for 35 h to obtain a single α-Al2O3 film layer (see Figure 1 b) (which can be confirmed by photoluminescence spectroscopy (PSLS) and scanning electron microscopy (SEM)), and the thickness is 3-4 μm.

[0069] (3) Place the sample obtained in step (2) into the thin film deposition chamber, and introduce appropriate Ar to maintain the pressure in the vacuum chamber at 4.5–5.2 × 10⁻⁶. -1 Pa. A pulse bias voltage of 600V, 30-40kHz, and 40% duty cycle was applied to the sample turntable. Bombardment cleaning was performed, simultaneously inducing dielectric barrier discharge for 10 minutes (the longer the time, the greater the number of through-holes). (See attached...) Figure 1 c). Micropores with a diameter of φ60~70μm will be formed on the sample surface, as shown in the attached image. Figure 2 As shown in b. Energy dispersive spectroscopy (EDS) confirmed that the formed hole is a through-hole, as shown in the attached figure. Figure 3 As shown.

[0070] (4) A Pt-containing metal coating is deposited on the sample surface in step (3) using magnetron sputtering (cathode arc deposition is also applicable). The deposition thickness is usually 4-6 μm. The deposition process is as follows: base vacuum 5×10 -3 Pa, sputtering pressure 6.5~7.5×10 -1 Pa, sputtering power 3.5–4.5 W, target-substrate spacing 10–12 cm.

[0071] (5) Place the sample coated in step (4) in a vacuum furnace and heat-treat it at 600°C for 100 hours to further stabilize the coating structure (see attached). Figure 1 d).

[0072] (6) The high-temperature oxidation test method was used to verify the blocking effect of the ceramic barrier layer and the stability of the coating structure. After constant temperature oxidation at 900℃ for 500h, no peeling, cracking, or wrinkling of the coating was observed. The surface composition of the coating was tested by energy dispersive spectroscopy, and no alloying elements such as Ni and Cr were found in the metal bonding layer and substrate below the ceramic barrier layer, indicating that the ceramic layer effectively blocked element diffusion and had excellent blocking performance.

[0073] Example 3

[0074] (1) A Ni-20Cr-10Al-0.2Y-0.3Si metal bonding layer with a thickness of 45–50 μm was prepared on a substrate sample of nickel-based superalloy DZ417G using a cathodic arc deposition process. Figure 1 a) The process is as follows: The DZ417G alloy substrate is surface-treated and activated according to GBⅡ373-1983 "General Rules for Surface Pretreatment of Thermally Sprayed Metal Parts" with an arc current of 80-100A. After deposition, it undergoes high-temperature vacuum heat treatment at 870℃ for 3 hours.

[0075] (2) The sample with the prepared adhesive layer was placed in a high-temperature muffle furnace at 1000-1050℃ for oxidization for 35 hours to obtain a single α-Al2O3 film (attached). Figure 1b) (can be confirmed by photo-stimulated luminescence spectroscopy (PSLS), scanning electron microscopy (SEM)), thickness of 3-4 μm.

[0076] (3) Put the sample from step (2) into a thin film deposition process chamber, introduce appropriate Ar, and make the air pressure in the vacuum chamber 4.5-5.2 x 10 -1 Pa. Apply a pulsed bias voltage of 1200 V, 30-40 kHz, and 40% duty cycle to the sample turntable. Perform bombardment cleaning while the dielectric barrier discharge occurs for 15 min (the longer the time, the more the number of through-holes) (see attached Figure 1 c). The sample surface will produce micro-holes with a diameter of 160-180 μm, as shown in attached Figure 2 c.

[0077] (4) Use cathodic arc deposition method (direct current magnetron sputtering and high-power pulsed magnetron sputtering are also applicable) to deposit an Au-containing metal coating on the sample surface of step (3), and the deposition thickness is usually 5-10 μm. The deposition process is as follows: base vacuum 5 x 10 - 3 Pa, deposition pressure 5.0 -2 Pa-7.3 x 10 -1 Pa, arc current 50-180 A, and target-to-substrate distance 10-15 cm.

[0078] (5) Put the sample with the deposited film of step (4) into a vacuum furnace and heat treat at 600°C for 100 h to further stabilize the coating structure.

[0079] (6) Use high-temperature oxidation test method to verify the barrier effect of the ceramic barrier layer and the stability of the coating structure. After constant temperature oxidation at 900°C for 500 h, no coating peeling, cracking, or wrinkling occurs. Use an energy-dispersive spectrometer to test the surface composition of the coating, and no alloy elements such as Ni and Cr from the metal bonding layer below the ceramic barrier layer and the substrate are found, indicating that the ceramic layer effectively blocks the diffusion of elements and has excellent barrier performance.

[0080] The preferred embodiments of the application disclosed above are only used to help explain the application, but the application is not limited thereto. Those skilled in the art can understand that, within the technical concept of the application, the technical solutions of the application can be modified, or some technical features can be combined in any other way, and these modifications or combinations do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the application, and should be considered as the disclosed content of the application, which all belongs to the protection scope of the application.

Claims

1. A method for producing a multilayer coating structure comprising a ceramic barrier layer, characterized in that The method comprises the following steps: S1) preparing a metal bonding layer: forming a metal bonding layer on the surface of the alloy substrate; S2) generating a thermal growth oxide layer: high-temperature oxidation treatment is performed on the metal bonding layer to generate a thermal growth oxide layer; S3) generating through micropores by dielectric barrier discharge: the thermal growth oxide layer is treated by dielectric barrier discharge to form through micropores on the surface of the thermal growth oxide layer, and the metal bonding layer is exposed at the bottom of the micropores; S4) preparing a metal coating: forming a metal coating on the surface of the thermal growth oxide layer with the generated through micropores; S5) high-temperature vacuum treatment to obtain a multilayer coating structure containing a ceramic barrier layer.

2. The production method according to claim 1, characterized by, The alloy substrate is selected from a nickel-based alloy; The metal bonding layer is selected from an MCrAlX coating, wherein M is selected from Ni and / or Co; X is selected from one or more of Y, Si and Hf; the mass content of Al in the metal bonding layer is 7% to 20%; and the thickness of the metal bonding layer is 25 to 50 μm.

3. The method of claim 1, wherein, The temperature of the high-temperature oxidation treatment in step S2) is 950°C to 1100°C; and the time of the high-temperature oxidation treatment is 30 to 35 h.

4. The method of claim 1, wherein, The voltage of the dielectric barrier discharge in step S3) is 200 to 1200 V, and the frequency is 25 to 40 kHz; and the treatment time is 10 to 60 min.

5. The preparation method according to claim 1, characterized in that, The thickness of the metal coating in step S4) is 0.5 to 10 μm.

6. The method of claim 1, wherein, The metal coating in step S4) is formed on the surface of the thermal growth oxide layer with the generated through micropores by physical vapor deposition; The physical vapor deposition is selected from magnetron sputtering or arc deposition; The base vacuum degree of the magnetron sputtering is 3*10 -3 ~5*10 -3 Pa; the working pressure of the magnetron sputtering is 5*10 -2 ~8*10 -1 Pa; the power of the magnetron sputtering is 2.5~4.5 W; and the target-substrate distance of the magnetron sputtering is 10~15 cm. The arc current of the arc deposition is 60 to 180 A; and the target-substrate distance of the arc deposition is 10 to 15 cm.

7. The preparation method according to claim 1, characterized in that, The temperature of the high-temperature vacuum treatment in step S5) is 600°C to 800°C; and the time of the high-temperature vacuum treatment is 30 to 100 h.

8. A multilayer coating structure with a ceramic barrier layer produced by the production method according to claim 1, characterized in that The method comprises: an alloy substrate; a metal bonding layer arranged on the surface of the alloy substrate; a ceramic barrier layer arranged on the surface of the metal bonding layer; the ceramic barrier layer comprises a thermal growth oxide layer and through micropores arranged on the thermal growth oxide layer; a metal coating arranged on the surface of the thermal growth oxide layer, and the metal coating is in contact with the metal bonding layer through the through micropores.

9. The multi-layered coating structure according to claim 8, wherein, The diameter of the through micropores is 20 to 180 μm; and the area ratio of the through micropores contained in the ceramic barrier layer is 0.5% to 1.5%.

10. The multi-layer coating structure according to claim 8, characterized in that The thickness of the thermal growth oxide layer is 1 to 5 μm.

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