A high-temperature-resistant multi-medium corrosion-resistant thermal / environmental barrier coating layer and a preparation method and application thereof

Abstract

The application discloses a high-temperature-resistant multi-medium-corrosion-resistant thermal / environmental barrier coating and a preparation method and application thereof. The coating has a four-layer structure, and sequentially comprises, from a substrate, a Si-Hf composite bonding layer, a double ytterbium silicate layer, a single ytterbium silicate layer and a high-entropy hafnate top layer. The bonding layer is prepared by a double-glow plasma metallurgy technology, has a continuous gradient structure, realizes good combination with a ceramic matrix composite substrate and thermal expansion matching, the double ytterbium silicate layer, the single ytterbium silicate layer and the high-entropy hafnate top layer are prepared by a plasma spraying-physical vapor deposition technology, and low porosity, high bonding strength and excellent phase stability of each layer are ensured. The coating can resist CMAS+NaVO3+H2O+O2 multi-medium corrosion for more than 100 hours in a high-temperature environment of 1600 DEG C. Through material composition design and multi-layer structure design, and in combination with a special preparation method, the service life of the coating under high-temperature multi-medium corrosion conditions is remarkably improved, and the coating has a good application prospect.

Description

Technical Field

[0001] This invention relates to the field of high-temperature protective coatings for aerospace engines, specifically to a thermal / environmental barrier coating resistant to high-temperature multi-media corrosion, its preparation method, and its application. Background Technology

[0002] The development of new aerospace engines towards higher thrust-to-weight ratios places stringent demands on the temperature resistance of hot-end component materials. Lightweight ultra-high-temperature structural materials, represented by ceramic matrix composites (CMCs), have become ideal choices to replace traditional nickel-based superalloys, achieving significant weight reduction and increased operating temperatures due to their high specific strength, excellent high-temperature creep resistance, and intrinsic high-temperature properties. However, in the extreme environments of actual engine service, CMCs face two core challenges: first, silicon-based materials undergo severe water-oxygen corrosion in high-temperature, oxygen-rich / water-vapor environments, generating volatile silanol products that lead to rapid material consumption and performance degradation; second, the surface temperature of the components must exceed the limits of long-term stable use of the base material. Therefore, it is essential to apply a multifunctional thermal / environmental barrier protective coating to the surface of the CMC.

[0003] Existing thermal protection coating systems are mostly designed around high-temperature alloys, with a typical structure consisting of an MCrAlY binder layer and a yttrium-stabilized zirconia ceramic surface layer. When the substrate is changed to CMC (carbon silicate), this system faces a fundamental mismatch. Therefore, research has shifted to environmental barrier coating materials represented by rare-earth silicates. However, single or simple bilayer silicate coatings have also revealed significant bottlenecks in long-term applications: 1) The mismatch in thermal expansion coefficients between the coating and the CMC substrate leads to the accumulation of enormous thermal stress at the interface under harsh thermal cycling loads, causing early coating spalling failure; 2) Existing coatings are mostly single-component or abruptly interfaceed, making it difficult to simultaneously optimize resistance to water and oxygen corrosion and strain tolerance; 3) At ultra-high temperatures of 1600℃ and above, the phase stability, low thermal conductivity maintenance, and high-temperature sintering resistance of traditional silicate coatings face severe challenges, with their thermal insulation capacity and lifespan rapidly declining. Therefore, developing a novel coating system that can stably match the CMC substrate and possesses excellent resistance to water and oxygen corrosion, high phase stability, long-lasting thermal insulation, and high resistance to thermal cycling spalling has become an urgent technical challenge. Summary of the Invention

[0004] This invention aims to overcome bottlenecks such as easy peeling, insufficient resistance to multi-media corrosion, and insufficient heat insulation capacity of coatings through a four-layer composite coating system and its reasonable preparation technology. It provides a thermal / environmental barrier coating resistant to high-temperature multi-media corrosion, along with its preparation method and application. The coating is a four-layer system of AHf₂O₇ / Yb₂SiO₅ / Yb₂Si₂O₇ / Si-Hf binder, and the preparation technology combines dual-glow plasma metallurgy with plasma spraying-physical vapor deposition.

[0005] To solve the problems of the prior art, the technical solution adopted by the present invention is as follows:

[0006] A thermal / environmental barrier coating resistant to high-temperature multi-media corrosion includes a ceramic matrix composite substrate, and further includes a Si-Hf composite adhesive layer, a bilayer silicate layer, and a feather / columnar high-entropy hafnium salt layer on the substrate. The adhesive layer has a thickness of 40-60 μm and has a continuous gradient structure; the bilayer silicate layer has a thickness of not less than 100 μm and includes a bilayer silicate layer and a single ytterbium silicate layer; the feather / columnar high-entropy hafnium salt layer has a thickness of not less than 150 μm.

[0007] Preferably, the Si-Hf composite adhesive layer material is Si, Hf, and HfSi compound, and the Hf content is 5~50 at.%.

[0008] Preferably, the bonding force of the adhesive layer with a continuous gradient structure is not less than 20 N, and the overall bonding strength of the thermal / environmental barrier coating is not less than 32 MPa.

[0009] Preferably, the double silicate layer is prepared using ytterbium disilicate and ytterbium monosilicate as raw materials and employing plasma spraying-physical vapor deposition technology.

[0010] Preferably, the composition of the feather / columnar high-entropy hafnium salt layer is AHf2O7, where A is a mixture of any five elements selected from Dy, Ho, Er, Tm, Lu, Ce, La, Gd, Sm and Yb in an equimolar ratio.

[0011] Preferably, the method for preparing the feather / column high-entropy hafnium salt layer is plasma spraying-physical vapor deposition technology, with a thermal conductivity of not more than 1.0 W / (m·K).

[0012] Preferably, the thermal / environmental barrier coating has been in service for more than 100 hours in a multi-media corrosion environment of CMAS + NaVO3 + H2O + O2 at 1600℃; the coating peeling rate is no more than 5%.

[0013] The method for preparing a heat / environmental barrier coating resistant to high-temperature multi-media corrosion as described in any of the above claims includes the following steps:

[0014] 1) Preparation of Si-Hf composite adhesive layer: Using high-purity Si and Hf plates as targets, the cleaned ceramic matrix composite substrate was deposited in an argon atmosphere using dual-glow plasma metallurgy. By adjusting the process parameters, the substrate temperature was controlled at 850-1050℃, so that the element content deposited on the substrate surface showed a continuous gradient change from Si-rich to Hf-rich along the thickness direction from the substrate to the top coating layer, thus forming a gradient adhesive layer with good thermophysical properties matched with the substrate. By adjusting the process parameters and controlling the substrate temperature at 850-1050℃, a gradient structure with a continuous change in chemical composition from the Si-rich side to the Hf-rich side was formed in situ on the substrate surface. The gradient design achieved a smooth transition of the coefficient of thermal expansion between the coating and the SiC substrate and established a strong and tough metallurgical bonding interface, fundamentally alleviating the interfacial thermal stress caused by CTE mismatch. On the other hand, the melting point of the Si-Hf composite adhesive layer is significantly higher than that of the pure Si adhesive layer at 1414℃.

[0015] 2) Preparation of Yb2Si2O7 layer: On the adhesive layer prepared in step 1, Yb2O3 and SiO2 mixed powder with stoichiometric ratio is fed into a plasma jet and deposited using plasma spraying-physical vapor deposition composite technology. First, a dense base layer is formed in the spraying mode. Then, the process parameters are adjusted to switch to the physical vapor deposition dominant mode, so that the material is vaporized and deposited on the substrate surface to form a Yb2Si2O7 ceramic layer with a dense structure.

[0016] 3) Preparation of Yb2SiO5 layer: On the Yb2Si2O7 ceramic layer, Yb2O3 and SiO2 mixed powder raw materials with the corresponding stoichiometric ratio of Yb2SiO5 are deposited using plasma spraying-physical vapor deposition composite technology. A dense Yb2SiO5 ceramic layer is deposited and grown on the surface of the Yb2Si2O7 layer, which serves as a core environmental barrier layer and provides excellent resistance to water and oxygen corrosion and high temperature phase stability.

[0017] 4) Preparation of High-Entropy Hafnium Salt (AHf2O7) Top Layer: An outermost layer is prepared on top of the Yb2SiO5 layer using a plasma spraying-physical vapor deposition (PVD) composite technique. A high-entropy composite powder, formulated with five rare earth oxides (such as Yb2O3 and Gd2O3) and HfO2, is used as the raw material. Through plasma spraying-PVD, a high-entropy hafnium salt top layer with a feather / columnar crystal structure is deposited, completing the preparation of the entire coating system. The A-sites of the high-entropy hafnium salt top layer are composed of five rare earth ions. Its high-entropy effect not only significantly reduces the intrinsic thermal conductivity of the material, providing excellent thermal insulation performance, but also greatly enhances the phase stability and anti-sintering ability of the coating at ultra-high temperatures, ensuring the durability of thermal insulation performance during long-term service. The feather / columnar structure endows the coating with a high strain tolerance to release thermal stress, while the micropores between the columnar crystals effectively scatter phonons, reducing the thermal conductivity of the coating.

[0018] The application of any of the above-mentioned heat / environmental barrier coatings resistant to high-temperature multi-media corrosion in high-temperature protective coatings for aerospace engines.

[0019] Beneficial effects

[0020] Compared with existing technologies, the core design concept of this invention lies in the design of material composition and multilayer structure. It proposes a novel multilayer thermal / environmental barrier coating system for CMC materials, applicable to extreme environments above 1600℃. Through a four-layer composite coating system and its rational preparation technology, it improves the bonding strength between the coating and the CMC substrate, the resistance to high-temperature multi-media corrosion, and the thermal insulation performance, achieving functional gradient and performance optimization. This provides a practical coating protection solution for the hot-end components of next-generation high-performance aerospace engines. Specifically, addressing issues such as interface bonding, interface matching, and melting point, it abandons traditional metal bonding layers and pure Si bonding layers, innovatively designing a Si-Hf composite bonding layer. Using dual-glow plasma metallurgy technology, a continuous gradient structure is constructed in situ on the substrate, achieving a smooth transition of thermal expansion coefficients and chemical-physical compatibility from the substrate to the ceramic layer. To meet the requirements of environmental and thermal barrier functions, a transition layer from ytterbium disilicate to ytterbium monosilicate is constructed. The former has better thermal expansion coefficient matching and corrosion resistance with the bonding layer, while the latter provides better high-temperature phase stability. The top layer employs high-entropy hafnium salt ceramics, utilizing the high-entropy effect to impart extremely low thermal conductivity, significantly suppressed element diffusion rates, and excellent phase structure stability at ultra-high temperatures. In terms of fabrication technology, the environmental barrier coating and thermal barrier coating are applied using a plasma spraying-physical vapor deposition composite technique to achieve a microstructure with low porosity, controllable columnar crystal structure, high bonding strength, and well-defined interlayer interfaces. Specific advantages are as follows:

[0021] 1) A Si-Hf composite bonding layer with a continuous compositional gradient was prepared on the surface of a CMC substrate using dual-glow plasma metallurgy technology. Chemically, a smooth transition from the substrate side to the ceramic layer side was achieved, effectively buffering the significant interfacial thermal stress caused by the difference in thermal expansion coefficients. Structurally, this technology formed a strong and tough metallurgical bonding interface that is distinctly different from traditional mechanical bonding, with a bonding strength far exceeding that of conventional thermal spray coatings. This improves the problem of interfacial cracking and early peeling caused by thermal cycling in traditional ceramic matrix composite coatings, enhancing the service reliability and service life of the coating system.

[0022] 2) A double-layer silicate structure was designed. The inner Yb₂Si₂O₇ layer provides good thermal matching while exhibiting excellent resistance to water and oxygen corrosion. The outer Y₂SiO₅ layer exhibits higher phase stability and lower silica activity in high-temperature steam environments above 1600℃. The combination of the two provides dual protection and optimizes interlayer matching. This system can more persistently and effectively block the diffusion of corrosive media such as oxygen and water vapor in high-temperature fuel gas into the matrix, significantly slowing down the water and oxygen corrosion rate of the SiC matrix, thereby greatly extending the service life of hot-end components in extreme environments.

[0023] 3) The high-entropy design concept is combined with hafnium salt materials and applied to the top layer of a thermal barrier coating. The severe lattice distortion effect introduced by various rare-earth cations in high-entropy hafnium salts strongly scatters phonons, thus endowing them with extremely low intrinsic thermal conductivity, resulting in significantly better thermal insulation performance than traditional YSZ materials. More importantly, the high-entropy effect can greatly suppress element diffusion and rapid grain coarsening at high temperatures, enabling the top layer to possess excellent long-term phase stability and anti-sintering ability in ultra-high temperature environments above 1600℃, maintaining low thermal conductivity and good strain tolerance for a long time. At the same time, the columnar crystal structure constructed by the plasma spraying-physical vapor deposition composite technology further enhances the strain tolerance of the coating. Attached Figure Description

[0024] Figure 1 The cross-sectional morphology of the thermal / environmental barrier coating prepared in Example 2;

[0025] Figure 2 The adhesion strength of the Si-Hf adhesive layer of the thermal / environmental barrier coating prepared in Example 2;

[0026] Figure 3 The cross-sectional morphology of the thermal / environmental barrier coating prepared in Example 2 after 100 h of multi-media corrosion at 1600℃ is shown.

[0027] Figure 4 The surface morphology of the thermal / environmental barrier coating prepared in Example 2 after 100 h of multi-media corrosion at 1600℃ is shown.

[0028] Figure 5This is a schematic diagram of the structure of the thermal / environmental barrier coating prepared according to the present invention. Detailed Implementation

[0029] The present invention will be further illustrated below through examples and comparative examples, but the present invention is not limited to the following examples. The bonding strength test was conducted according to JB / T8554-1997 standard, the bonding power test according to GB / T 8642-2002 standard, and the thermal conductivity test according to Q / AVIC 06019-2013 standard.

[0030] Example 1

[0031] A four-layer structure sample with a total coating thickness of approximately 320 μm was prepared.

[0032] First, a Si-Hf gradient binder layer with a thickness of approximately 50 μm was prepared using dual-glow plasma metallurgy. During the deposition process, the substrate temperature was controlled at 850℃, resulting in a continuous gradient change in the chemical composition of the binder layer: the Hf content was approximately 20 at.% near the substrate; and increased to 40 at.% towards the surface of the binder layer.

[0033] Subsequently, a plasma spraying-physical vapor deposition composite technique was used to deposit subsequent ceramic layers sequentially. First, a ytterbium double silicate layer and a ytterbium monosilica layer of approximately 120 μm thickness were deposited. The process parameters were: current 2650 A, argon flow rate 80 L / min, helium flow rate 20 L / min, powder feed rate 20 g / min, spray distance 1000 mm, and preheating temperature 920 °C.

[0034] Finally, a high-entropy hafnium salt top layer was prepared, in which the A-site was composed of five rare earth elements—Yb, Gd, Y, Sm, and Dy—in an equimolar ratio. The high-entropy composite powder prepared from the five rare earth oxides and HfO2 was used as the raw material. The chemical formula of the prepared high-entropy hafnium salt top layer is (Yb... 0.2 Gd 00.2 Y 0.2 Sm 0.2 Dy 0.2 The Hf₂O₇ powder has a thickness of approximately 150 μm. The process parameters are as follows: current 2650A, argon flow rate 30 L / min, helium flow rate 55 L / min, powder feed rate 20 g / min, spray distance 1000 mm, and preheating temperature 1020℃.

[0035] Test results show that the bonding force of the Si-Hf adhesive layer is 20.6 N, the overall coating bonding strength is 32 MPa, the thermal conductivity of the high-entropy hafnium salt top layer is 0.96 (W / (m·K)) at 1600°C, and the peeling area of ​​the coating after 100h of multi-media corrosion at 1600°C is <3%.

[0036] Example 2

[0037] A four-layer structure sample with a total coating thickness of approximately 315 μm was prepared, and the structure is as follows: Figure 1 As shown.

[0038] First, a Si-Hf gradient binder layer with a thickness of approximately 45 μm was prepared using dual-glow plasma metallurgy. During deposition, the substrate temperature was controlled at 950℃, allowing for a continuous gradient change in the chemical composition of the binder layer: the Hf content was approximately 10 at.% near the substrate; increasing to 30 at.% towards the surface. Subsequently, subsequent ceramic layers were deposited sequentially using a plasma spraying-physical vapor deposition composite technique. A 110 μm thick ytterbium silicate double layer followed by a ytterbium silicate monolayer was deposited first. The process parameters were: current 2650 A, argon flow rate 80 L / min, helium flow rate 20 L / min, powder feed rate 20 g / min, spray distance 1000 mm, and preheating temperature 920℃.

[0039] Finally, a high-entropy hafnium salt top layer was prepared, in which the A-site was composed of five rare earth elements, Dy, Ho, Er, Tm, and Lu, in an equimolar ratio. The high-entropy composite powder prepared from the five rare earth oxides and HfO2 was used as the raw material. The chemical formula of the prepared high-entropy hafnium salt top layer is (Dy... 0.2 Ho 0.2 Er 0.2 Tm 0.2 Lu 0.2 The powder used was 2Hf2O7 with a thickness of approximately 160 μm. The process parameters were: current of 2650A, argon flow rate of 30 L / min, helium flow rate of 55 L / min, powder feed rate of 20 g / min, spray distance of 1000 mm, and preheating temperature of 1020℃.

[0040] Test results show that the bonding strength of the Si-Hf adhesive layer is 25.8 N (see...). Figure 2 The overall coating bonding strength is 38 MPa. The thermal conductivity of the high-entropy hafnium salt top layer is 0.82 W / (m·K) at 1600°C. No peeling occurred after 100 hours of multi-media corrosion at 1600°C. The coating morphology before and after corrosion is shown in [reference needed]. Figure 1 , Figure 3 and Figure 4 .

[0041] Example 3

[0042] A four-layer structure sample with a total coating thickness of approximately 330 μm was prepared.

[0043] First, a Si-Hf gradient binder layer with a thickness of approximately 60 μm was prepared using dual-glow plasma metallurgy. During the deposition process, the substrate temperature was controlled at 1050℃, allowing for a continuous gradient change in the chemical composition of the binder layer: near the substrate, the Hf content was approximately 5 at.%; towards the surface of the binder layer, the Hf content increased to 25 at.%.

[0044] Subsequently, a plasma spraying-physical vapor deposition composite technique was used to deposit subsequent ceramic layers sequentially. First, a ytterbium double silicate layer and a ytterbium monosilica layer of approximately 100 μm thickness were deposited. The process parameters were: current 2650 A, argon flow rate 80 L / min, helium flow rate 20 L / min, powder feed rate 20 g / min, spray distance 1000 mm, and preheating temperature 920 °C.

[0045] Finally, a high-entropy hafnium salt top layer was prepared, in which the A-site was composed of five rare earth elements, Yb, La, Ce, Gd, and Ho, in an equimolar ratio. Using a high-entropy composite powder prepared from the five rare earth oxides and HfO2 as raw material, the chemical formula of the prepared high-entropy hafnium salt top layer was (Yb... 0.2 La 0.2 Ce 0.2 Gd 0.2 Ho 0.2 The powder used was 2Hf2O7 with a thickness of approximately 170 μm. The process parameters were: current of 2650A, argon flow rate of 30 L / min, helium flow rate of 55 L / min, powder feed rate of 20 g / min, spray distance of 1000 mm, and preheating temperature of 1020℃.

[0046] Test results show that the bonding force of the Si-Hf adhesive layer is 21.7 N, the overall coating bonding strength is 36 MPa, the thermal conductivity of the high-entropy hafnium salt top layer is 0.88 (W / (m·K)) at 1600°C, and the coating peeling area after 100h of multi-media corrosion at 1600°C is <2%.

[0047] Comparative Example 1

[0048] A coating with a gradient-free structure and a single-material top layer was prepared using a conventional atmospheric plasma spraying process for comparison. First, a constant-composition coating (Si-20 at.% Hf) of approximately 50 μm thick was sprayed using APS as a binder layer. Next, a silicate layer of approximately 110 μm thick was sprayed using APS. Finally, a high-entropy hafnium salt material of approximately 160 μm thick was sprayed as the top layer. All coatings exhibited typical lamellar stacking structures, lacking columnar crystals and compositional gradients. Test results showed that the Si-Hf binder layer had a bonding force of 10.7 N, the overall coating bonding strength was 18 MPa, the thermal conductivity of the high-entropy hafnium salt top layer at 1600 °C was 0.92 (W / (m·K), and the coating peeling area after 100 h of multi-media corrosion at 1600 °C was >40%.

[0049] Comparative Example 2

[0050] The adhesive layer and silicate layer are the same as in Example 2, with the top layer being a single Yb2Hf2O7 material. Test results show that the thermal conductivity of the single hafnium salt top layer is 1.65 (W / (m·K)) at 1600°C, and the coating peeling area is >20% after 100h of multi-media corrosion at 1600°C.

[0051] Table 1 Statistical Analysis of Experimental Results

[0052]

Claims

1. A thermal / environmental barrier coating resistant to high-temperature multi-media corrosion, comprising a ceramic matrix composite matrix, characterized in that, It also includes, from the substrate upwards, a Si-Hf composite bonding layer, a bilayer silicate layer, and a feather / column high-entropy hafnium salt layer. The bonding layer has a thickness of 40-60 μm and a continuous gradient structure; the bilayer silicate layer has a thickness of not less than 100 μm and includes a bilayer silicate layer and a single ytterbium silicate layer; the feather / column high-entropy hafnium salt layer has a thickness of not less than 150 μm.

2. The thermal / environmental barrier coating resistant to high-temperature multi-media corrosion according to claim 1, characterized in that, The Si-Hf composite adhesive layer material is composed of Si, Hf, and HfSi compound, with the Hf content being 5-50 at.%.

3. The thermal / environmental barrier coating resistant to high-temperature multi-media corrosion according to claim 1, characterized in that, The bonding force of the adhesive layer with a continuous gradient structure is not less than 20 N, and the overall bonding strength of the thermal / environmental barrier coating is not less than 32 MPa.

4. The thermal / environmental barrier coating resistant to high-temperature multi-media corrosion according to claim 1, characterized in that, The aforementioned double silicate layer is prepared using ytterbium disilicate and ytterbium monosilicate as raw materials and employing plasma spraying-physical vapor deposition technology.

5. The thermal / environmental barrier coating resistant to high-temperature multi-media corrosion according to claim 1, characterized in that, The composition of the feather / column-shaped high-entropy hafnium salt layer is AHf2O7, where A is a mixture of any five elements selected from Dy, Ho, Er, Tm, Lu, Ce, La, Gd, Sm and Yb in an equimolar ratio.

6. The heat / environmental barrier coating resistant to high-temperature multi-media corrosion according to claim 5, characterized in that, The method for preparing the feather / column-shaped high-entropy hafnium salt layer is plasma spraying-physical vapor deposition technology, with a thermal conductivity of no more than 1.0 W / (m·K).

7. The thermal / environmental barrier coating resistant to high-temperature multi-media corrosion according to claim 1, characterized in that, The thermal / environmental barrier coating has been in service for more than 100 hours in a multi-media corrosion environment of CMAS + NaVO3 + H2O + O2 at 1600℃; the coating peeling rate is no more than 5%.

8. A method for preparing a heat / environmental barrier coating resistant to high-temperature multi-medium corrosion according to any one of claims 1-7, characterized in that, Includes the following steps: 1) Preparation of Si-Hf composite adhesive layer: Using high-purity Si plates and Hf plates as target materials, the cleaned ceramic matrix composite matrix is ​​deposited in an argon atmosphere using double glow plasma metallurgy technology. By adjusting the process parameters, the matrix temperature is controlled at 850-1050℃, so that the element content deposited on the matrix surface shows a continuous gradient change from Si-rich to Hf-rich in the thickness direction from the matrix to the top coating layer, thereby forming a gradient adhesive layer with good thermophysical properties matched with the matrix and ytterbium silicate layer. 2) Preparation of Yb2Si2O7 layer: On the adhesive layer prepared in step 1, a mixture of Yb2O3 and SiO2 powders in stoichiometric ratio is fed into a plasma jet and deposited using a plasma spraying-physical vapor deposition composite technology. First, a dense base layer is formed in the spraying mode. Then, the process parameters are adjusted to switch to the physical vapor deposition dominant mode, so that the material is vaporized and deposited on the substrate surface to form a Yb2Si2O7 ceramic layer with a dense structure. 3) Preparation of Yb2SiO5 layer: On the Yb2Si2O7 ceramic layer, Yb2O3 and SiO2 mixed powder raw materials with the corresponding stoichiometric ratio of Yb2SiO5 are deposited using plasma spraying-physical vapor deposition composite technology to deposit and grow a Yb2SiO5 ceramic layer with a dense structure on the surface of the Yb2Si2O7 layer. 4) Preparation of high-entropy hafnium salt (AHf2O7) top layer: The outermost layer is prepared on top of the Yb2SiO5 layer using plasma spraying-physical vapor deposition composite technology; using high-entropy composite powder prepared by five rare earth oxides (such as Yb2O3, Gd2O3, etc.) and HfO2 as raw material, a high-entropy hafnium salt top layer with feather / columnar crystal structure is deposited through plasma spraying-physical vapor deposition composite technology to complete the preparation of the entire coating system.

9. The application of a high-temperature multi-medium corrosion resistant thermal / environmental barrier coating based on any one of claims 1-7 in a high-temperature protective coating for aerospace engines.

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