Semi-crystalline multi-component ceramic coating, and preparation and use thereof

Abstract

The present invention relates to the technical field of corrosion-resistant coatings, and in particular to a semi-crystalline multi-component ceramic coating, and preparation and use thereof. In the present invention, ZrO2, SiO2, CaO, TiO2, K2O, MnO2, Fe2O3, BaO, CuO, ZnO, NiO, a boride, and a dispersant are subjected to ball milling, then dissolved in a solvent, and mixed uniformly to obtain a semi-crystalline multi-component ceramic slurry; and finally, the semi-crystalline multi-component ceramic slurry is coated on the surface of a pretreated substrate, and subjected to drying treatment and high-temperature firing treatment in sequence to obtain the semi-crystalline multi-component ceramic coating bonded to the substrate. By means of the semi-crystalline multi-component ceramic coating provided by the present invention, defects such as through-holes, through cracks, and grain boundaries inside the coating can be eliminated, with a porosity of less than 1.5%. Under long-term hydrothermal conditions, the material also has a self-healing repair capability, thereby greatly improving the service life of the material in a hydrothermal environment.

Description

A semi-crystalline multi-element ceramic coating and its preparation and application Technical Field

[0001] This invention relates to the field of corrosion-resistant coating technology, and in particular to a semi-crystalline multi-element ceramic coating and its preparation and application. Background Technology

[0002] In the development of high-end technologies such as aerospace and advanced energy, ceramic coatings have become key protective materials due to their excellent high-temperature resistance, wear resistance, and chemical stability. However, high-temperature water vapor environments have become a severe challenge for ceramic coatings in practical applications. In the aerospace field, the combustion of aviation fuel generates a large amount of water vapor. High-temperature water vapor can penetrate into the coating through pores and microcracks, reacting chemically with the metal substrate, accelerating its corrosion, and promoting the rapid growth of thermally grown oxides, ultimately leading to delamination and peeling of the coating. Furthermore, high-temperature water vapor environments can cause expansion and decomposition of ceramic coatings, resulting in numerous cracks, a significant decrease in adhesion, and severe impact on durability.

[0003] Similarly, water heater inner tanks and hydrothermal reactor inner wall materials, used in both civilian and industrial applications, face similar challenges in hydrothermal environments. Currently, water heater inner tank coatings mostly use materials such as enamel coatings and organic coatings. While enamel coatings possess certain corrosion and wear resistance, they are prone to developing bubbles or pinholes during production. Furthermore, due to their brittleness, vibrations and impacts during transportation and installation can easily cause scaling. In long-term high-temperature hydrothermal environments, coating peeling and cracking are also common. Organic coatings, on the other hand, suffer from performance degradation due to high-temperature hydrolysis and oxidation, leading to coating peeling and protective failure. In addition, magnesium and calcium ions, as well as dissolved oxygen and carbon dioxide, can cause electrochemical corrosion. Oxygen undergoes a reduction reaction on the coating surface, while the metal elements in the coating lose electrons and undergo oxidation, forming corrosion cells and accelerating coating corrosion failure. In high-temperature and high-pressure hydrothermal environments, grain boundaries in the material tend to become preferential corrosion sites. Intergranular corrosion weakens the bonding force between grains, reducing the material's strength and toughness, severely impacting its service life and safety.

[0004] Existing coating materials all exhibit varying degrees of performance defects in hydrothermal environments, failing to meet the protection requirements of aerospace, advanced energy, and civilian industries for stable performance and structure, resistance to high-temperature hydrothermal corrosion, and long service life. Therefore, it is crucial to develop a semi-crystalline multi-element ceramic coating that is not prone to peeling or blistering, does not easily generate penetrating cracks, and has good density. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide a semi-crystalline multi-element ceramic coating and its preparation and application. The semi-crystalline multi-element ceramic coating provided by the present invention is not prone to peeling or blistering, and is less likely to develop penetrating cracks, exhibiting good density (low porosity and high density). Furthermore, it does not undergo chemical reactions, decomposition, or aging during hydrothermal corrosion, demonstrating high chemical stability. Even after long-term high-temperature hydrothermal cycling, the ceramic coating maintains good integrity and interfacial adhesion to the metal substrate.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] The first objective of this invention is to provide a method for preparing a semi-crystalline multi-element ceramic coating, comprising the following steps:

[0008] (S1) 48-52 parts ZrO2, 20-25 parts SiO2, 10-15 parts CaO, 3-6 parts TiO2, 1-3 parts K2O, 1-3 parts MnO2, 1-3 parts Fe2O3, 1-3 parts BaO, 0.5-1 parts CuO, 0.5-1 parts ZnO, 0.5-1 parts NiO, 0.5-2 parts borides and 0.1-0.3 parts dispersant were ball-milled to obtain semi-crystalline multi-element ceramic powder;

[0009] (S2) Dissolve the semi-crystalline multi-element ceramic powder obtained in step (S1) in a solvent and mix well to obtain a semi-crystalline multi-element ceramic slurry;

[0010] (S3) The semi-crystalline multi-element ceramic slurry prepared in step (S2) is coated on the pretreated substrate surface, and then dried and fired at high temperature to obtain a semi-crystalline multi-element ceramic coating that is bonded to the substrate.

[0011] In one embodiment of the present invention, in step (S1), the boride is selected from one or more of TiB2, TiBN, ZrSiB6, ZrB2, ZrBN, HfB2, HfBN, ZrSiBCN, ZrTiBCN, HfZrSiBCN, or HfZrTiBCN;

[0012] The dispersant is selected from one or more of polymaleic acid, polyacrylic acid, polycarboxylic acid ester, or maleic acid-acrylic acid copolymer.

[0013] In one embodiment of the present invention, in step (S1), during the ball milling process, the rotation speed is 1500-4000 r / min and the time is 10-15 min.

[0014] In one embodiment of the present invention, in step (S2), the mass ratio of semi-crystalline multi-element ceramic powder to solvent is 1:0.3 to 0.4;

[0015] Mixing refers to stirring and mixing, during which defoaming agent is added dropwise, and the stirring speed is 300-600 r / min.

[0016] In one embodiment of the present invention, the defoamer is selected from one or more of polyoxypropylene ethylene glycerol ether (GPE), polyoxypropylene glycerol ether (GP), polyoxypropylene polyoxyethylene glycerol ether stearate (GPES), polypropylene glycol glycerol ether, polyether polyol or silicone polyether.

[0017] In one embodiment of the present invention, in step (S3), the coating method is a leveling method;

[0018] The pretreated substrate specifically refers to a substrate that undergoes grinding, washing, and drying processes in sequence.

[0019] In one embodiment of the present invention, 400-800 grit metallographic sandpaper is used for polishing to remove the oxide layer on the surface of the substrate;

[0020] The ultrasonic cleaning process was carried out using ethanol for 10–20 minutes.

[0021] During the drying process, the temperature is 50-80℃ and the time is 20-60 minutes.

[0022] In one embodiment of the present invention, in step (S3), the drying process is carried out at a temperature of 100-115°C for 10-20 minutes.

[0023] In one embodiment of the present invention, in step (S3), the high-temperature firing process is carried out at a temperature of 775-850°C for 10-20 minutes.

[0024] In one embodiment of the present invention, the thickness of the semi-crystalline multi-element ceramic coating is 100–600 μm;

[0025] Preferably, the thickness of the semi-crystalline multi-element ceramic coating is 150–300 μm.

[0026] In this invention, at the initial stage of the preparation process of the semi-crystalline multi-element ceramic coating, the coating covering the metal substrate is not dense, but contains some pores and cracks, allowing oxygen to reach the substrate and react with it to generate FeO or Fe3O4. As the temperature rises, the semi-crystalline multi-element ceramic coating begins to melt and densify, blocking the oxygen transport channels and preventing further oxide film growth. Simultaneously, FeO or Fe3O4 reacts with components such as SiO2 and B2O3 in the semi-crystalline multi-element ceramic coating to form Fe-Si-O and Fe-BO composite oxide interface layers. At high temperatures, the Fe in the metal substrate... 2+ / Fe 3+Si in semi-crystalline multi-element ceramic coating 4+ B 3+ Plasma diffuses and mixes at the interface, forming a gradient diffusion layer. The Fe-Si-O structure in the diffusion layer is microscopically bonded to the metal substrate by covalent or ionic bonds, forming chemical anchors that ensure a tight bond between the semi-crystalline multi-element ceramic coating and the substrate.

[0027] Borides, as self-healing components, allow boron atoms to form dynamic covalent bonds with oxygen atoms, known as borate ester bonds. Under specific conditions, when a material is damaged, these borate ester bonds break, releasing boric acid and other substances that react with surrounding hydroxyl-containing substances to form new borate ester bonds, thus filling the cracks and enabling the material to self-repair through bond rearrangement. Furthermore, borides readily react with oxygen at low temperatures (~500℃), forming a liquid borosilicate glass phase with SiO2, exhibiting good fluidity and adhesion. In high-temperature environments, this glassy borosilicate melts and flows to the damaged areas, filling and healing cracks. Upon cooling, it forms a continuous, dense glass film, ensuring the material's mechanical properties and integrity while reducing corrosion damage.

[0028] The second objective of this invention is to provide a semi-crystalline multi-element ceramic coating, prepared by the above method. This semi-crystalline multi-element ceramic coating can eliminate defects such as internal pores, through cracks, and grain boundaries, with a porosity of less than 1.5%. Under long-term hydrothermal conditions, the material also has self-healing and repair capabilities, and its service life in hydrothermal environments is greatly improved (with good mechanical properties).

[0029] A third objective of this invention is to provide an application of a semi-crystalline multi-element ceramic coating in the aerospace field.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] (1) The addition of boride self-healing components to the semi-crystalline multi-element ceramic coating prepared by the present invention can significantly reduce the viscosity of the ceramic in the molten state, which is conducive to the floating of bubbles, reduces the formation of through holes in the coating, and effectively improves the density of the coating; and during the hydrothermal corrosion process, the boride will react with oxygen to generate glassy borosilicates, which repair defects such as cracks and holes in the enamel and prevent water vapor from penetrating.

[0032] (2) The standard protective current of the semi-crystalline multi-element ceramic coating prepared by this invention is as low as 0.059 mA / m 2 Compared to existing corrosion-resistant ceramic coatings (12mA / m 2 It decreased by two orders of magnitude.

[0033] (3) The semi-crystalline multi-element ceramic coating prepared by the present invention has excellent resistance to high temperature hydrothermal corrosion, greatly improves service life, and has a simple preparation process and low maintenance cost, and has broad application prospects. Attached Figure Description

[0034] Figure 1 shows cross-sectional SEM images of the semi-crystalline multi-element ceramic coating prepared in Example 1 and the conventional ceramic coating prepared in Comparative Example 1.

[0035] Figure 2 shows SEM images of the surfaces of the semi-crystalline multi-element ceramic coating prepared in Example 1 and the conventional ceramic coating prepared in Comparative Example 1 after high-temperature hydrothermal corrosion.

[0036] Figure 3 shows the Nyquist plots of the semi-crystalline multi-element ceramic coating prepared in Example 1 and the conventional ceramic coating prepared in Comparative Example 1.

[0037] Figure 4 shows the Bode diagrams of the semi-crystalline multi-element ceramic coating prepared in Example 1 and the conventional ceramic coating prepared in Comparative Example 1.

[0038] Figure 5 shows the XRD patterns of the semi-crystalline multi-element ceramic coating prepared in Example 2 and the conventional ceramic coating prepared in Comparative Example 1. Detailed Implementation

[0039] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0040] In the following embodiments, the high-energy ball mill used was a UNIONPROCESS grinding mill, model 01-HDDM, manufactured by Qingdao Lianrui Precision Instruments Co., Ltd.; the high-temperature box furnace was a Shangguang XLC-1400C box furnace manufactured by Shanghai Daheng Optics Precision Machinery Co., Ltd.; unless otherwise specified, all reagents used were commercially available reagents, and all detection methods and techniques used were conventional detection methods and techniques in the field.

[0041] Example 1

[0042] This embodiment provides a method for preparing a semi-crystalline multi-element ceramic coating, including the following steps:

[0043] (S1) Polish the surface of the metal substrate with 400-grit sandpaper to remove the oxide layer, then ultrasonically clean it with ethanol for 15 minutes, and dry it in an oven at 80°C for 20 minutes to obtain the pretreated metal substrate.

[0044] (S2) Mix 50 parts ZrO2, 23 parts SiO2, 12 parts CaO, 5 parts TiO2, 2 parts K2O, 1.5 parts MnO2, 1.8 parts Fe2O3, 1.6 parts BaO, 0.8 parts CuO, 0.7 parts ZnO, 0.6 parts NiO, 1 part ZrSiB6 and 0.2 parts polymaleic acid and then ball mill them (2000 r / min for 10 min). After ball milling, dry to constant weight to obtain a uniformly mixed semi-crystalline multi-element ceramic powder.

[0045] (S3) The semi-crystalline multi-element ceramic powder prepared in step (S2) is mixed with pure water at a mass ratio of 1:0.33 and placed in an Erlenmeyer flask for mechanical stirring (400 r / min for 10 min). During the stirring process, GPE defoamer is added dropwise to obtain semi-crystalline multi-element ceramic slurry.

[0046] (S4) The semi-crystalline multi-element ceramic slurry from step (S3) is uniformly coated onto the surface of the metal substrate prepared in step (S1) using the leveling method; then it is placed in an oven at 110°C for 15 min to dry, and then placed in a box furnace at 800°C for sintering at high temperature for 15 min to obtain a semi-crystalline multi-element ceramic coating that is well bonded to the metal substrate and has high density and is resistant to high temperature hydrothermal corrosion. The coating thickness is about 150 μm.

[0047] Comparative Example 1

[0048] This comparative example provides a method for preparing a traditional ceramic coating, specifically including the following steps:

[0049] (S1) Polish the surface of the metal substrate with 400-grit sandpaper to remove the oxide layer, then ultrasonically clean it with ethanol for 15 minutes, and dry it in an oven at 80°C for 20 minutes to obtain the pretreated metal substrate.

[0050] (S2) Mix 50 parts ZrO2, 23 parts SiO2, 12 parts CaO, 5 parts TiO2, 2 parts K2O, 1.5 parts MnO2, 1.8 parts Fe2O3, 1.6 parts BaO, 0.8 parts CuO, 0.7 parts ZnO, and 0.6 parts NiO, and then ball mill them (2000 r / min for 10 min). After ball milling, dry them to constant weight to obtain a uniformly mixed traditional ceramic powder.

[0051] (S3) The traditional ceramic powder prepared in step (S2) and pure water are placed in an Erlenmeyer flask at a mass ratio of 1:0.33 and mechanically stirred (400 r / min for 10 min) to obtain traditional ceramic slurry;

[0052] (S4) The conventional ceramic slurry from step (S3) is uniformly applied to the surface of the metal substrate prepared in step (S1) using the leveling method; then it is placed in an oven at 110°C for 15 min to dry, and then placed in a box furnace at 800°C for sintering at high temperature for 15 min to obtain a conventional ceramic coating that is well bonded to the metal substrate with a coating thickness of about 150 μm.

[0053] Figure 1 shows SEM images of the cross-sections of the conventional ceramic coating prepared in Comparative Example 1 (Figure 1a) and the semi-crystalline multi-element ceramic coating prepared in Example 1 (Figure 1b). Figure 1 reveals that the conventional ceramic coating contains numerous pores, providing a pathway for high-temperature water vapor to penetrate. The semi-crystalline multi-element ceramic coating prepared in Example 1 has a thickness of approximately 150 μm, and a transitional bonding layer exists between the metal substrate and the semi-crystalline multi-element ceramic coating, forming numerous anchor points, indicating a tight interface between the semi-crystalline multi-element ceramic coating and the metal substrate. Furthermore, the cross-section of the semi-crystalline multi-element ceramic coating shows almost no spherical pores, significantly reducing the coating porosity and increasing its density.

[0054] Figure 2 shows SEM images of the surfaces of the conventional ceramic coating prepared in Comparative Example 1 (Figure 2a) and the semi-crystalline multi-element ceramic coating prepared in Example 1 (Figure 2b) after 20 days of high-temperature hydrothermal corrosion. Figure 2 reveals that before hydrothermal corrosion, bulges or cracks appeared in the conventional ceramic coating. After hydrothermal corrosion, the bulges and cracks widened and lengthened, providing more pathways for subsequent water vapor and oxygen penetration, accelerating the corrosion failure of the coating and substrate. In contrast, the semi-crystalline multi-element ceramic coating prepared in Example 1 maintained high integrity after high-temperature hydrothermal corrosion and formed a large amount of flocculent products that covered and filled some of the cracks, hindering the penetration of water vapor and oxygen and delaying the corrosion of the metal substrate by water vapor.

[0055] Figures 3 and 4 show the electrochemical test results of the conventional ceramic coating prepared in Comparative Example 1 and the semi-crystalline multi-element ceramic coating prepared in Example 1, respectively, in a 3.5 wt.% NaCl solution. The corrosion resistance of the coating can be measured by the magnitude of its impedance value; generally, the higher the impedance value, the better its corrosion resistance. By comparing the Nyquist and Bode plots of the conventional ceramic coating and the semi-crystalline multi-element ceramic coating, it can be found that the high-frequency capacitive arc of the semi-crystalline multi-element ceramic coating is greater than that of the enamel coating, and the impedance modulus is significantly improved. This indicates that the diffusion process of ions in the semi-crystalline multi-element ceramic coating is hindered, the difficulty of ions penetrating the coating increases, the density of the coating is greatly improved, and the corrosion resistance is significantly enhanced.

[0056] Example 2

[0057] This embodiment provides a method for preparing a semi-crystalline multi-element ceramic coating, including the following steps:

[0058] (S1) Polish the surface of the metal substrate with 600-grit sandpaper to remove the oxide layer, then ultrasonically clean it with ethanol for 10 min, and dry it in an oven at 75°C for 30 min to obtain the pretreated metal substrate.

[0059] (S2) 51 parts ZrO2, 22 parts SiO2, 13 parts CaO, 4 parts TiO2, 2.1 parts K2O, 1.6 parts MnO2, 1.7 parts Fe2O3, 1.5 parts BaO, 0.7 parts CuO, 0.8 parts ZnO, 0.5 parts NiO, 2 parts HfZrSiBCN and 0.15 parts polyacrylic acid were mixed and then ball-milled (2500 r / min for 15 min). After ball milling, the mixture was dried to constant weight to obtain a uniformly mixed semi-crystalline multi-element ceramic powder.

[0060] (S3) The semi-crystalline multi-element ceramic powder prepared in step (S2) and pure water are placed in an Erlenmeyer flask at a mass ratio of 1:0.3 and mechanically stirred (500 r / min for 15 min). During the stirring process, GP defoamer is added dropwise to obtain semi-crystalline multi-element ceramic slurry.

[0061] (S4) The semi-crystalline multi-element ceramic slurry from step (S3) is uniformly coated onto the surface of the metal substrate prepared in step (S1) using the leveling method; then it is placed in an oven at 100°C for 20 min to dry, and then placed in a box furnace at 825°C for sintering at high temperature for 12 min to obtain a semi-crystalline multi-element ceramic coating that is well bonded to the metal substrate and has high density and is resistant to high temperature hydrothermal corrosion. The coating thickness is about 300 μm.

[0062] Figure 5 shows the XRD patterns of the semi-crystalline multi-element ceramic coating prepared in Example 2 and the conventional ceramic coating prepared in Comparative Example 1. Both ceramic coatings exhibit SiO2 diffraction peaks, but compared with the conventional ceramic coating, the diffraction peak intensity of the semi-crystalline multi-element ceramic coating is significantly reduced, and a distinct peak is observed in the 20–40° range, indicating an increased degree of amorphization.

[0063] Example 3

[0064] This embodiment provides a method for preparing a semi-crystalline multi-element ceramic coating, including the following steps:

[0065] (S1) Polish the surface of the metal substrate with 800-grit sandpaper to remove the oxide layer, then ultrasonically clean it with ethanol for 12 minutes, and dry it in an oven at 70°C for 35 minutes to obtain the pretreated metal substrate.

[0066] (S2) 49 parts ZrO2, 24 parts SiO2, 14 parts CaO, 3 parts TiO2, 2.5 parts K2O, 2.2 parts MnO2, 1.5 parts Fe2O3, 2 parts BaO, 0.6 parts CuO, 0.9 parts ZnO, 0.7 parts NiO, 1.5 parts ZrTiBCN and 0.18 parts polycarboxylate were mixed and then ball-milled (3000 r / min for 12 min). After ball milling, the mixture was dried to constant weight to obtain a uniformly mixed semi-crystalline multi-element ceramic powder.

[0067] (S3) The semi-crystalline multi-element ceramic powder prepared in step (S2) is mixed with pure water at a mass ratio of 1:0.35 and placed in an Erlenmeyer flask for mechanical stirring (350 r / min for 15 min). During the stirring process, GPES defoaming agent is added dropwise to obtain semi-crystalline multi-element ceramic slurry.

[0068] (S4) The semi-crystalline multi-element ceramic slurry from step (S3) is uniformly coated onto the surface of the metal substrate prepared in step (S1) using the leveling method; then it is placed in an oven at 105°C for 17 min to dry, and then placed in a box furnace at 850°C for sintering at high temperature for 10 min to obtain a semi-crystalline multi-element ceramic coating that is well bonded to the metal substrate and has high density and is resistant to high temperature hydrothermal corrosion. The coating thickness is about 420 μm.

[0069] Example 4

[0070] This embodiment provides a method for preparing a semi-crystalline multi-element ceramic coating, including the following steps:

[0071] (S1) Polish the surface of the metal substrate with 600-grit sandpaper to remove the oxide layer, then ultrasonically clean it with ethanol for 10 min, and dry it in an oven at 60℃ for 50 min to obtain the pretreated metal substrate.

[0072] (S2) Mix 52 parts ZrO2, 25 parts SiO2, 11 parts CaO, 6 parts TiO2, 1.9 parts K2O, 2.5 parts MnO2, 2.1 parts Fe2O3, 2.3 parts BaO, 0.9 parts CuO, 0.6 parts ZnO, 0.8 parts NiO, 0.8 parts TiBN, and 0.25 parts polycarboxylate, and then ball mill (3500 r / min for 10 min). After ball milling, dry to constant weight to obtain a uniformly mixed semi-crystalline multi-element ceramic powder.

[0073] (S3) The semi-crystalline multi-element ceramic powder prepared in step (S2) and pure water are placed in an Erlenmeyer flask at a mass ratio of 1:0.4 and mechanically stirred (500 r / min for 13 min). During the stirring process, GPES defoamer is added dropwise to obtain semi-crystalline multi-element ceramic slurry.

[0074] (S4) The semi-crystalline multi-element ceramic slurry from step (S3) is uniformly coated onto the surface of the metal substrate prepared in step (S1) using the leveling method; then it is placed in an oven at 115°C for 10 min to dry, and then placed in a box furnace at 775°C for sintering at high temperature for 18 min to obtain a semi-crystalline multi-element ceramic coating that is well bonded to the metal substrate and has high density and is resistant to high temperature hydrothermal corrosion. The coating thickness is about 600 μm.

[0075] Table 1. Porosity and Standard Protection Current of Semi-crystalline Multi-element Ceramic Coatings and Traditional Ceramic Coatings

[0076] As can be seen from Table 1, the porosity of the semi-crystalline multi-element ceramic coatings prepared in Examples 1 to 4 is about 10% of that of the traditional ceramic coatings, the standard protection current is reduced by two orders of magnitude compared with the traditional ceramic coatings, and the density of the semi-crystalline multi-element ceramic coatings is significantly improved.

[0077] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the interpretation of the present invention, without departing from the scope of the invention, should be within the protection scope of the present invention.

Claims

1. A method for preparing a semi-crystalline multi-element ceramic coating, characterized in that, Includes the following steps: (S1) 48-52 parts ZrO2, 20-25 parts SiO2, 10-15 parts CaO, 3-6 parts TiO2, 1-3 parts K2O, 1-3 parts MnO2, 1-3 parts Fe2O3, 1-3 parts BaO, 0.5-1 parts CuO, 0.5-1 parts ZnO, 0.5-1 parts NiO, 0.5-2 parts borides and 0.1-0.3 parts dispersant were ball-milled to obtain semi-crystalline multi-element ceramic powder; (S2) Dissolve the semi-crystalline multi-element ceramic powder obtained in step (S1) in a solvent and mix well to obtain a semi-crystalline multi-element ceramic slurry; (S3) The semi-crystalline multi-element ceramic slurry prepared in step (S2) is coated on the pretreated substrate surface, and then dried and fired at high temperature to obtain a semi-crystalline multi-element ceramic coating that is bonded to the substrate.

2. The method for preparing a semi-crystalline multi-element ceramic coating according to claim 1, characterized in that, In step (S1), the boride is selected from one or more of TiB2, TiBN, ZrSiB6, ZrB2, ZrBN, HfB2, HfBN, ZrSiBCN, ZrTiBCN, HfZrSiBCN, or HfZrTiBCN; The dispersant is selected from one or more of polymaleic acid, polyacrylic acid, polycarboxylic acid ester, or maleic acid-acrylic acid copolymer.

3. The method for preparing a semi-crystalline multi-element ceramic coating according to claim 1, characterized in that, In step (S1), during the ball milling process, the rotation speed is 1500-4000 r / min and the time is 10-15 min.

4. The method for preparing a semi-crystalline multi-element ceramic coating according to claim 1, characterized in that, In step (S2), the mass ratio of semi-crystalline multi-element ceramic powder to solvent is 1:0.3 to 0.4; Mixing means stirring and mixing thoroughly, and adding defoamer dropwise during the stirring process.

5. The method for preparing a semi-crystalline multi-element ceramic coating according to claim 4, characterized in that, The defoamer is selected from one or more of polyoxypropylene ethylene glycerol ether, polyoxypropylene glycerol ether, polyoxypropylene polyoxyethylene glycerol ether stearate, polypropylene glycol glycerol ether, polyether polyol or silicone polyether.

6. The method for preparing a semi-crystalline multi-element ceramic coating according to claim 1, characterized in that, In step (S3), the coating method is the leveling method; The pretreated substrate specifically refers to a substrate that undergoes grinding, washing, and drying processes in sequence.

7. The method for preparing a semi-crystalline multi-element ceramic coating according to claim 1, characterized in that, In step (S3), the drying process is carried out at a temperature of 100–115°C for 10–20 minutes. During the high-temperature firing process, the temperature is 775–850℃ and the time is 10–20 minutes.

8. The method for preparing a semi-crystalline multi-element ceramic coating according to claim 1, characterized in that, In step (S3), the thickness of the semi-crystalline multi-element ceramic coating is 100–600 μm.

9. A semi-crystalline multi-element ceramic coating, characterized in that, It is prepared by the method described in any one of claims 1 to 8.

10. An application of the semi-crystalline multi-element ceramic coating as described in claim 9 in the aerospace field.

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