Special fire-resistant anti-adhesion ceramic coating of boron nitride side sealing plate for thin-strip continuous casting and preparation method of special fire-resistant anti-adhesion ceramic coating

Abstract

The invention belongs to the technical field of preparation of green special fire-resistant ceramics and functional coatings for continuous casting, and provides a special fire-resistant anti-adhesion ceramic coating for a boron nitride side sealing plate for thin-strip continuous casting and a preparation method of the special fire-resistant anti-adhesion ceramic coating. The preparation method comprises the following steps: forming a hollow structure by taking polymer microspheres as a template, dipping in a cerium salt solution and sintering; preparing coated zirconium boride, mixing zirconium boride with silicon dioxide powder, depositing an aluminum phosphate protective film on the surface of the mixture, and performing heat treatment and curing; compounding the boron nitride sheets and the silicon carbide nanowires, and performing surface treatment to obtain a mixed reinforcing material; the materials are prepared into three-layer slurry with a gradient function, then the boron nitride side sealing plate base body is coated with the bonding layer, the functional layer and the working layer in sequence, low-temperature pre-sintering is conducted on the multi-layer structure, and finally rapid densification of the coating is achieved through the spark plasma sintering technology. And constructing a special fire-resistant anti-adhesion functional layer taking an inorganic ceramic phase as a main body.

Description

Technical Field

[0001] This invention belongs to the technical field of green special refractory ceramics and functional coatings for continuous casting, and relates to a special refractory and anti-adhesion ceramic coating for boron nitride side sealing plates for thin strip continuous casting and its preparation method. Background Technology

[0002] Thin-strip continuous casting technology is a cutting-edge technology in the iron and steel metallurgy field, with significant advantages in energy saving, emission reduction, cost reduction, and efficiency improvement. However, the boron nitride side sealing plate, used to define the width of the molten metal in the core equipment of this technology, operates in an extremely harsh environment. The side sealing plate needs to withstand the intense thermal shock of high-temperature molten steel, chemical corrosion, and mechanical wear from high-speed rotating crystallizing rolls for extended periods, resulting in a short service life. Frequent replacement not only increases production costs but also seriously affects the continuity and stability of production. Furthermore, it increases the consumption of refractory materials for the side sealing plate, which is detrimental to achieving green metallurgy and efficient resource utilization.

[0003] To extend the service life of side sealing plates, applying a high-performance, special refractory, and anti-adhesion coating to their surface is currently the mainstream technical solution. Existing protective coatings are mostly composed of single or simple composite ceramic materials, such as alumina and zirconium oxide. While these coatings can improve the high-temperature resistance and wear resistance of the side sealing plates to some extent, they often struggle to simultaneously meet multiple performance requirements, including thermal shock resistance. Under complex service conditions, traditional coatings are prone to cracking and rapid propagation due to thermal expansion mismatch, leading to premature peeling and failure. This makes it difficult to meet the application requirements of long-life, low-consumption, and environmentally friendly special refractory ceramic materials in thin-strip continuous casting conditions. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a special refractory and anti-adhesion ceramic coating for boron nitride side sealing plates used in thin strip continuous casting and its preparation method. This involves preparing a hollow microsphere with a multi-shell structure, a zirconium boride-coated surface, and a composite reinforcing material as the core functional filler. These fillers are distributed in a specific ratio in the bonding layer, functional layer, and working layer and coated onto the boron nitride side sealing plate. The coating is then prepared through low-temperature pre-firing and spark plasma sintering processes, thus meeting the needs of actual production.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a method for preparing a special refractory and anti-adhesion ceramic coating for boron nitride side sealing plates used in thin strip continuous casting, the preparation method comprising:

[0007] S1, a silica sol is obtained by mixing tetraethoxysilane with an aqueous ethanol solution, aluminum isopropoxide is dispersed in ethanol to obtain an aluminum sol, the silica sol and aluminum sol are added sequentially to a PMMA (polymethyl methacrylate) dispersion, and then immersed in a boron solution to obtain coated microspheres. The coated microspheres are kept warm to obtain hollow spheres, and the hollow spheres are immersed in a cerium nitrate solution, dried and kept warm to obtain hollow microspheres;

[0008] S2, zirconium boride and silicon dioxide are added to anhydrous ethanol to obtain a suspension, aluminum nitrate nonahydrate is dispersed in deionized water to obtain an aluminum nitrate solution, phosphoric acid is added to the aluminum nitrate solution to obtain an aluminum phosphorus solution, and the aluminum phosphorus solution is added to the suspension to obtain coated zirconium boride.

[0009] S3, hexagonal boron nitride is dispersed in anhydrous isopropanol and ultrasonicated to obtain boron nitride flakes. The boron nitride flakes and SiC nanowires are dispersed in isopropanol, and then 3-aminopropyltriethoxysilane is added to isopropanol and stirred to obtain a mixed reinforcing material.

[0010] S4. The boron nitride side sealing plate is coated with a bonding layer, a functional layer and a working layer in sequence, and then pre-fired and sintered at low temperature to obtain a special fire-resistant and anti-adhesion ceramic coating for boron nitride side sealing plate for thin strip continuous casting.

[0011] Specifically, it includes:

[0012] S1, mix tetraethoxysilane with an aqueous ethanol solution, adjust the pH to 3-4, and stir at room temperature to obtain a silica sol. Disperse aluminum isopropoxide in ethanol and stir to obtain an aluminum sol. Add the silica sol and aluminum sol to the PMMA dispersion in sequence, stir to coat, centrifuge, wash and dry. Then, immerse the dried PMMA microspheres in a boron solution and dry to obtain coated microspheres. Place the coated microspheres in an electric resistance furnace under an air atmosphere, heat to the first temperature and hold to obtain hollow spheres. Immerse the hollow spheres in a cerium nitrate solution, dry and place in an electric resistance furnace, heat to the second temperature and hold, cool to room temperature, pulverize and sieve to obtain hollow microspheres.

[0013] S2, zirconium boride and silicon dioxide are added to anhydrous ethanol and mixed evenly to obtain a suspension. Aluminum nitrate nonahydrate is dispersed in deionized water to obtain aluminum nitrate solution. Phosphoric acid is added to the aluminum nitrate solution to adjust the pH to 1-3 to obtain aluminum phosphorus solution. The aluminum phosphorus solution is added to the suspension, stirred and reacted, centrifuged, washed, dried and placed at the third temperature to obtain coated zirconium boride.

[0014] S3, hexagonal boron nitride is dispersed in anhydrous isopropanol, sonicated under ice bath conditions, centrifuged after sonication and the supernatant is collected. After centrifugation, washing and drying of the supernatant, boron nitride flakes are obtained. The boron nitride flakes and SiC nanowires are dispersed in isopropanol and mixed evenly. Then 3-aminopropyltriethoxysilane is added to isopropanol and stirred. After filtration, washing and drying, the mixed reinforcing material is obtained.

[0015] S4. The boron nitride side sealing plate is coated with a bonding layer, a functional layer and a working layer in sequence, and then pre-fired and sintered at low temperature to obtain a special fire-resistant and anti-adhesion ceramic coating for boron nitride side sealing plate for thin strip continuous casting.

[0016] The anti-adhesion coating prepared in this invention possesses comprehensive protective performance derived from the synergistic effect of multiple functional units within a specific gradient structure. Firstly, the coating's thermal shock resistance and insulation mechanism are primarily undertaken by hollow microspheres. The hollow structure of the microspheres contains a low thermal conductivity gas phase. When the coating surface is impacted by the hot flow of molten steel, a large amount of heat energy is blocked and scattered by the porous structure within the microspheres, reducing the rate of heat transfer from the coating surface to the boron nitride substrate and decreasing the temperature gradient between the substrate and the coating, thereby reducing thermal stress caused by thermal expansion mismatch. Simultaneously, when subjected to thermal stress, the shell structure of the microspheres dissipates energy through its own micro-elastic deformation or controllable micro-fractures, preventing the formation and propagation of macroscopic cracks. The outermost layer of cerium oxide in the microspheres is chemically stable at high temperatures, acting as a physical barrier to inhibit the direct erosion of the mullite shell by active elements in the molten steel.

[0017] Secondly, zirconium boride undergoes an oxidation reaction in a high-temperature, oxygen-containing environment, producing zirconium oxide and liquid boron trioxide. Without coating treatment, this reaction rate is too fast, and the generated boron trioxide is easily volatilized and lost at high temperatures. The aluminum phosphate coating layer in this invention acts as a semi-permeable physical barrier at high temperatures, limiting the diffusion rate of oxygen to the surface of the zirconium boride particles. This allows the oxidation reaction to proceed at a controlled and slow rate, giving the generated boron trioxide sufficient time to react with the pre-incorporated silica to form a borosilicate glass phase with higher viscosity and lower volatility. When microcracks develop within the coating due to stress, this in-situ generated, highly fluid liquid glass phase fills the cracks, solidifies upon cooling, and repairs the damage, restoring the structural integrity of the coating.

[0018] Furthermore, boron nitride flakes, as two-dimensional nanomaterials, primarily function as interfacial isolation and crack deflection in the coating. When a crack tip encounters a two-dimensional flake, its propagation path is forced to change, increasing the energy consumption for crack propagation. Silicon carbide nanowires, as reinforcements, form a three-dimensional network framework in the coating due to their high strength and high modulus. When the coating is subjected to load, these fibers bear most of the stress through bridging and pull-out mechanisms, effectively preventing microcracks from becoming macrocracks. The 3-aminopropyltriethoxysilane coupling agent hydrolyzes on the reinforcement surface to form silanol groups, which can undergo condensation reactions with hydroxyl groups in the matrix material to form chemical bonds, thereby improving the interfacial bonding strength between the reinforcement and the matrix and ensuring that stress can be effectively transferred from the matrix to the reinforcement.

[0019] Finally, the concentrations of each functional component change in a gradient from the bonding layer to the working layer. The bonding layer, mainly composed of matrix powder, ensures physicochemical compatibility and adhesion with the boron nitride substrate. The functional layer, enriched with hollow microspheres and coated zirconium boride, is the core area for thermal insulation and self-healing functions. The working layer, mainly composed of mixed reinforcing materials, provides a wear-resistant and low-wetting interface directly facing the molten steel, avoiding interfacial stress concentration. Axial pressure is applied simultaneously during spark plasma sintering, achieving low-temperature and rapid densification, effectively suppressing volatilization and phase transformation of the material at high temperatures, and ensuring the integrity of the microstructure of each functional unit.

[0020] As a preferred embodiment of the present invention, in S1, the mass ratio of tetraethoxysilane, aqueous ethanol solution, aluminum isopropoxide, ethanol, PMMA dispersion, boron solution, and cerium nitrate solution is (60-80):(250-300):(50-70):(80-100):500:145:200, for example, it can be (60, 62, 64, 66, 68, 70, 72, 74, 76, 78, or 80):(250) / (250) / (300) / (400) / (50-70) / (80-100):500:145:200, or (60, 62, 64, 66, 68, 70, 72, 74, 76, 78, or 80):(250) / (50-70) / (80-10 ... 255, 260, 265, 270, 275, 280, 285, 290, 295 or 300: (50, 52, 54, 56, 58, 60, 62, 64, 66, 68 or 70): (80, 82, 84, 86, 88, 90, 92, 94, 96, 98 or 100): 500:145:200, but not limited to the listed values; other unlisted values ​​within this range also apply.

[0021] In some optional embodiments, the volume ratio of ethanol to deionized water in the aqueous ethanol solution is 3:2.

[0022] In some optional embodiments, the mass ratio of PMMA microspheres to deionized water in the PMMA dispersion is 1:10.

[0023] In some optional embodiments, the stirring time at room temperature is 100-120 min, for example, it can be 100 min, 102 min, 104 min, 106 min, 108 min, 110 min, 112 min, 114 min, 116 min, 118 min or 120 min, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0024] In some optional embodiments, the stirring and coating time is 200-240 min, for example, it can be 200 min, 204 min, 208 min, 212 min, 216 min, 220 min, 224 min, 228 min, 232 min, 236 min or 240 min, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0025] In some optional embodiments, the mass ratio of boric acid to ethanol in the boron solution is 4:25.

[0026] In some optional embodiments, the immersion time in the boron solution is 150-180 min, for example, 150 min, 153 min, 156 min, 159 min, 162 min, 165 min, 168 min, 171 min, 174 min, 177 min or 180 min, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0027] In some alternative embodiments, the first temperature is 700-850°C, for example, it can be 700°C, 715°C, 730°C, 745°C, 760°C, 775°C, 790°C, 805°C, 820°C, 835°C or 850°C, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0028] In some optional embodiments, the holding time at the first temperature is 150-180 min, for example, it can be 150 min, 153 min, 156 min, 159 min, 162 min, 165 min, 168 min, 171 min, 174 min, 177 min or 180 min, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0029] In some optional embodiments, the concentration of the cerium nitrate solution is 0.1 mol / L.

[0030] In some optional embodiments, the immersion time in the cerium nitrate solution is 180-200 min, for example, it can be 180 min, 182 min, 184 min, 186 min, 188 min, 190 min, 192 min, 194 min, 196 min, 198 min or 200 min, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0031] In some alternative embodiments, the second temperature is 1300-1400°C, for example, it can be 1300°C, 1310°C, 1320°C, 1330°C, 1340°C, 1350°C, 1360°C, 1370°C, 1380°C, 1390°C or 1400°C, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0032] In some optional embodiments, the holding time at the second temperature is 260-300 min, for example, it can be 260 min, 264 min, 268 min, 272 min, 276 min, 280 min, 284 min, 288 min, 292 min, 296 min or 300 min, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0033] As a preferred technical solution of the present invention, in S2, the mass ratio of zirconium boride, silicon dioxide, anhydrous ethanol, aluminum nitrate nonahydrate, and deionized water is (60-80):(8-15):250:(8-15):100. For example, it can be (60, 62, 64, 66, 68, 70, 72, 74, 76, 78 or 80):(8, 8.7, 9.4, 10.1, 10.8, 11.5, 12.2, 12.9, 13.6, 14.3 or 15):250:(8, 8.7, 9.4, 10.1, 10.8, 11.5, 12.2, 12.9, 13.6, 14.3 or 15):100, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0034] In some optional embodiments, the stirring reaction time is 200-240 min, for example, 200 min, 204 min, 208 min, 212 min, 216 min, 220 min, 224 min, 228 min, 232 min, 236 min or 240 min, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0035] In some alternative embodiments, the third temperature is 700-800°C, for example, it can be 700°C, 710°C, 720°C, 730°C, 740°C, 750°C, 760°C, 770°C, 780°C, 790°C or 800°C, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0036] In some optional embodiments, the time for holding the third temperature is 100-120 min, for example, it can be 100 min, 102 min, 104 min, 106 min, 108 min, 110 min, 112 min, 114 min, 116 min, 118 min or 120 min, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0037] As a preferred technical solution of the present invention, in S3, the mass ratio of hexagonal boron nitride to anhydrous isopropanol is (50-60):(200-300), for example, it can be (50, 51, 52, 53, 54, 55, 56, 57, 58, 59 or 60):(200, 210, 220, 230, 240, 250, 260, 270, 280, 290 or 300), but it is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0038] In some alternative embodiments, the ultrasound duration is 30-36 hours, for example, 30.0 hours, 30.6 hours, 31.2 hours, 31.8 hours, 32.4 hours, 33.0 hours, 33.6 hours, 34.2 hours, 34.8 hours, 35.4 hours, or 36.0 hours, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0039] In some optional embodiments, the mass ratio of the boron nitride sheet, SiC nanowires, isopropanol, and 3-aminopropyltriethoxysilane is (20-30):(20-30):200:(2-4), for example, (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30):(20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30):200:(2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6, 3.8, or 4.0), but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0040] In some optional embodiments, the SiC nanowires have a length of 50-100 μm and a diameter of <500 nm. For example, they may have a length of (50, 55, 60, 65, 70, 75, 80, 85, 90, 95 or 100) μm and a diameter of <500 nm, but are not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0041] In some optional embodiments, the stirring time in the isopropanol is 60-80 min, for example, 60 min, 62 min, 64 min, 66 min, 68 min, 70 min, 72 min, 74 min, 76 min, 78 min or 80 min, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0042] As a preferred technical solution of the present invention, in S4, the mass ratio of hexagonal boron nitride powder, hollow microspheres, coated zirconium boride, alumina powder, 3-aminopropyltrimethoxysilane, ethanol and isopropanol in the bonding layer is (200-260):(10-20):(5-10):(40-60):(5-8):(300-380):(80-140). After being mixed evenly, the mixture is ground with three rollers, and the spraying thickness is 60-80μm. After drying, it proceeds to the next stage. For example, the mass ratios could be (200, 206, 212, 218, 224, 230, 236, 242, 248, 254, or 260): (10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20): (5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, or 10): (40, 42, 44, 46, 48, 50, 52, 54, 56, 58, or 60): (5.0, 5.3, 5.6, 5.9, 6.2, 6.5, 6.8, 7.1, 7... 4, 7.7 or 8.0): (300, 308, 316, 324, 332, 340, 348, 356, 364, 372 or 380): (80, 86, 92, 98, 104, 110, 116, 122, 128, 134 or 140), after mixing evenly, three-roll milling, the spray thickness is (60, 62, 64, 66, 68, 70, 72, 74, 76, 78 or 80) μm, after drying, proceed to the next stage, but not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0043] In some optional embodiments, in the functional layer, the mass ratio of hexagonal boron nitride powder, hollow microspheres, coated zirconium boride, silica nanoparticles, mixed reinforcing material, alumina powder, ethanol, isopropanol and barium carbonate is (160-200):(30-40):(25-35):(8-12):(10-20):(30-40):(300-360):(50-90):(2-8). After being mixed evenly, the mixture is ground with three rollers, and the coating thickness is 200-240 μm. After drying, it proceeds to the next stage. For example, the mass ratios could be (160, 164, 168, 172, 176, 180, 184, 188, 192, 196, or 200): (30, 31, 32, 33, 34, 35, 36, 37, 38, 39, or 40): (25, 26, 27, 28, 29, 30, 31, 32, 33, 34, or 35): (8.0, 8.4, 8.8, 9.2, 9.6, 10.0, 10.4, 10.8, 11.2, 11.6, or 12.0): (10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20): (30, 31, 32, 33, 34, 35, 36, 37, 38) (300, 306, 312, 318, 324, 330, 336, 342, 348, 354 or 360): (50, 54, 58, 62, 66, 70, 74, 78, 82, 86 or 90): (2.0, 2.6, 3.2, 3.8, 4.4, 5.0, 5.6, 6.2, 6.8, 7.4 or 8.0), after mixing evenly, three-roll milling, spraying thickness of (200, 204, 208, 212, 216, 220, 224, 228, 232, 236 or 240) μm, after drying to proceed to the next stage, but not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0044] In some optional embodiments, in the working layer, the mass ratio of the mixed reinforcing material, hollow microspheres, coated zirconium boride, fluorinated silica, ethanol and isopropanol is (20-30):(5-10):(8-12):(10-15):(300-360):(50-90), and after being mixed evenly, it is ground with three rollers, and the coating thickness is 130-160μm. For example, the mass ratio could be (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30): (5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, or 10): (8.0, 8.4, 8.8, 9.2, 9.6, 10.0, 10.4, 10.8, 11.2, 11.6, or 12.0): (10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, or 15): (300, 306, 312, 318, 324, 330, 336, 342, 348, 354 or 360): (50, 54, 58, 62, 66, 70, 74, 78, 82, 86 or 90), after uniform mixing, three-roll milling, the spray thickness is (130, 133, 136, 139, 142, 145, 148, 151, 154, 157 or 160) μm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0045] In some optional embodiments, the low-temperature preheating is to heat to 600-800℃ at a heating rate of 5℃ / min and hold for 1-1.5 hours, then cool to room temperature. For example, it can be to heat to (600, 620, 640, 660, 680, 700, 720, 740, 760, 780 or 800)℃ at a heating rate of 5℃ / min and hold for (1.0, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45 or 1.5) hours, then cool to room temperature. However, it is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0046] In some optional embodiments, the sintering is spark plasma sintering, in which an axial pressure of 20-30 MPa is applied during the sintering process, the temperature is raised to 1250-1320°C, the holding time is 7-10 min, and the furnace is cooled to room temperature. For example, it could be: spark plasma sintering, during which an axial pressure of (20, 21, 22, 23, 24, 25, 26, 27, 28, 29 or 30) MPa is applied, the temperature is raised to (1250, 1257, 1264, 1271, 1278, 1285, 1292, 1299, 1306, 1313 or 1320) °C, the holding time is (7.0, 7.3, 7.6, 7.9, 8.2, 8.5, 8.8, 9.1, 9.4, 9.7 or 10.0) min, and then cooled to room temperature with the furnace. However, it is not limited to the values ​​listed, and other unlisted values ​​within this range are also applicable.

[0047] In a second aspect, the present invention provides a special refractory and anti-adhesion ceramic coating for boron nitride side sealing plates used in thin strip continuous casting, prepared by the preparation method described in the first aspect.

[0048] Compared with existing technologies, the beneficial effects of this invention are as follows: This invention prepares a multi-shell microsphere with an internal hollow core and an external passivation layer, and introduces it into the coating system to enhance the coating's heat insulation and buffering capacity and thermal shock resistance, delaying damage accumulation during thin strip continuous casting service; by surface coating zirconium boride, the oxidation reaction rate at high temperatures is effectively controlled, enabling the generated low-melting-point phase to fill microcracks in a timely manner, improving the coating's self-healing ability and high-temperature density; by compositing multi-scale reinforcing phases such as nanosheets and nanowires, a three-dimensional reinforcing network is constructed inside the coating, improving the coating's fracture toughness and mechanical strength, effectively preventing large-area peeling, and extending the high-temperature service life of the boron nitride side sealing plate; the gradient layered structure design optimizes the stress distribution between the coating and the substrate, improves the bonding strength, reduces the frequency of side sealing plate replacement and refractory material consumption, meeting the requirements of green special refractory ceramics for long-life and resource-friendly applications. Detailed Implementation

[0049] The technical solution of the present invention will be described in detail below with reference to specific embodiments. The embodiments described herein are specific implementations of the present invention and are used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary and should not be construed as limiting the implementation of the present invention or the scope of protection of the present invention. In addition to the embodiments described herein, those skilled in the art can also adopt other obvious technical solutions based on the content disclosed in the claims and the specification of this application. These technical solutions include those that make any obvious substitutions and modifications to the embodiments described herein.

[0050] The chemical reagents used in the embodiments and comparative examples of this invention are all commercially available products and have not undergone any further purification treatment.

[0051] Example 1

[0052] This embodiment provides a special refractory and anti-adhesion ceramic coating for boron nitride side sealing plates used in thin strip continuous casting and its preparation method. The preparation method specifically includes the following steps:

[0053] S1, mix 60g of tetraethoxysilane with 300g of an aqueous ethanol solution, wherein the volume ratio of ethanol to deionized water in the aqueous ethanol solution is 3:2, adjust the pH to 3, and stir at room temperature for 120 min to obtain a silica sol. Disperse 70g of aluminum isopropoxide in 80g of ethanol and stir to obtain an aluminum sol. Add the silica sol and aluminum sol sequentially to 500g of... In a PMMA dispersion, the mass ratio of PMMA microspheres to deionized water is 1:10. The mixture is stirred and coated for 200 min, centrifuged, washed, and dried. The dried PMMA microspheres are then immersed in 145 g of boron solution for 180 min, where the mass ratio of boric acid to ethanol is 4:25. After drying, coated microspheres are obtained. These coated microspheres are then placed in an electric resistance furnace under air atmosphere and heated to 850 °C for 150 min to obtain hollow spheres. The hollow spheres are then immersed in 200 g of 0.1 mol / L cerium nitrate solution for 200 min, dried, and placed in an electric resistance furnace. The temperature is then raised to 1300 °C and held for 300 min. After cooling to room temperature, the microspheres are pulverized and sieved to obtain hollow microspheres.

[0054] S2, 80g of zirconium boride and 8g of silicon dioxide were added to 250g of anhydrous ethanol and mixed evenly to obtain a suspension. 15g of aluminum nitrate nonahydrate was dispersed in 100g of deionized water to obtain an aluminum nitrate solution. Phosphoric acid was added to the aluminum nitrate solution to adjust the pH to 1 to obtain an aluminum phosphorus solution. The aluminum phosphorus solution was added to the suspension and stirred for 240min. After centrifugation, washing, and drying, the solution was kept at 800℃ for 100min to obtain coated zirconium boride.

[0055] S3, 50g of hexagonal boron nitride was dispersed in 300g of anhydrous isopropanol and sonicated for 36h under ice bath conditions. After sonication, the supernatant was collected by centrifugation. The supernatant was centrifuged, washed, and dried to obtain boron nitride flakes. 30g of boron nitride flakes and 20g of SiC nanowires were dispersed in 200g of isopropanol and mixed evenly. The length of the SiC nanowires was 50-100μm and the diameter was <500nm. Then 2g of 3-aminopropyltriethoxysilane was added to the isopropanol and stirred for 80min. After filtration, washing, and drying, the mixed reinforcing material was obtained.

[0056] S4, the boron nitride side sealing plate is sequentially coated with a bonding layer, a functional layer, and a working layer. In the bonding layer, the mass ratio of hexagonal boron nitride powder, hollow microspheres, coated zirconium boride, alumina powder, 3-aminopropyltrimethoxysilane, ethanol, and isopropanol is 200:20:5:60:8:300:140. After uniform mixing, it is three-roll milled to a coating thickness of 60 μm. After drying, it proceeds to the next stage. In the functional layer, the mass ratio of hexagonal boron nitride powder, hollow microspheres, coated zirconium boride, silica nanoparticles, mixed reinforcing material, alumina powder, ethanol, isopropanol, and barium carbonate is 160:40:25:12:10:40:360:50:8. After uniform mixing, it is three-roll milled to a coating thickness of 2 μm. After drying to a thickness of 00μm, the next stage begins. In the working layer, the mass ratio of mixed reinforcing material, hollow microspheres, coated zirconium boride, fluorine-modified silica, ethanol, and isopropanol is 20:10:12:10:300:90. After uniform mixing, the mixture is ground using a three-roll mill, and the spray thickness is 160μm. Then, low-temperature pre-firing and sintering are performed. The low-temperature pre-firing involves heating to 800℃ at a heating rate of 5℃ / min and holding for 1 hour. After holding, the temperature is cooled to room temperature. The sintering is performed by spark plasma sintering. During the sintering process, an axial pressure of 30MPa is applied, the temperature is raised to 1250℃, and the holding time is 10 minutes. The temperature is then cooled to room temperature with the furnace to obtain a special refractory and anti-adhesion ceramic coating for boron nitride side sealing plates used in thin strip continuous casting.

[0057] Example 2

[0058] This embodiment provides a special refractory and anti-adhesion ceramic coating for boron nitride side sealing plates used in thin strip continuous casting and its preparation method. The preparation method specifically includes the following steps:

[0059] S1, mix 80g of tetraethoxysilane with 250g of an ethanol-water solution (ethanol to deionized water volume ratio 3:2), adjust the pH to 4, and stir at room temperature for 100min to obtain a silica sol. Disperse 50g of aluminum isopropoxide in 100g of ethanol and stir to obtain an aluminum sol. Add the silica sol and aluminum sol sequentially to 500g of... In a PMMA dispersion, the mass ratio of PMMA microspheres to deionized water is 1:10. The mixture is stirred and coated for 240 min, centrifuged, washed, and dried. The dried PMMA microspheres are then immersed in 145 g of boron solution for 150 min, where the mass ratio of boric acid to ethanol is 4:25. After drying, coated microspheres are obtained. The coated microspheres are then placed in an electric resistance furnace under air atmosphere and heated to 700 °C for 180 min to obtain hollow spheres. The hollow spheres are then immersed in 200 g of 0.1 mol / L cerium nitrate solution for 180 min, dried, and placed in an electric resistance furnace. The temperature is then raised to 1400 °C and held for 260 min. After cooling to room temperature, the microspheres are pulverized and sieved to obtain hollow microspheres.

[0060] S2, 60g of zirconium boride and 15g of silicon dioxide were added to 250g of anhydrous ethanol and mixed evenly to obtain a suspension. 8g of aluminum nitrate nonahydrate was dispersed in 100g of deionized water to obtain an aluminum nitrate solution. Phosphoric acid was added to the aluminum nitrate solution to adjust the pH to 3 to obtain an aluminum phosphorus solution. The aluminum phosphorus solution was added to the suspension and stirred for 200min. After centrifugation, washing, and drying, the solution was kept at 700℃ for 120min to obtain coated zirconium boride.

[0061] S3, 60g of hexagonal boron nitride was dispersed in 200g of anhydrous isopropanol and sonicated for 30h under ice bath conditions. After sonication, the supernatant was collected by centrifugation. After centrifugation, washing, and drying of the supernatant, boron nitride flakes were obtained. 20g of boron nitride flakes and 30g of SiC nanowires were dispersed in 200g of isopropanol and mixed evenly. The length of the SiC nanowires was 50-100μm and the diameter was <500nm. Then, 4g of 3-aminopropyltriethoxysilane was added to the isopropanol and stirred for 60min. After filtration, washing, and drying, the mixed reinforcing material was obtained.

[0062] S4, the boron nitride side sealing plate is sequentially coated with a bonding layer, a functional layer, and a working layer. In the bonding layer, the mass ratio of hexagonal boron nitride powder, hollow microspheres, coated zirconium boride, alumina powder, 3-aminopropyltrimethoxysilane, ethanol, and isopropanol is 260:10:10:40:5:380:80. After uniform mixing, the mixture is three-roll milled to a coating thickness of 80 μm. After drying, it proceeds to the next stage. In the functional layer, the mass ratio of hexagonal boron nitride powder, hollow microspheres, coated zirconium boride, silica nanoparticles, mixed reinforcing material, alumina powder, ethanol, isopropanol, and barium carbonate is 200:30:35:8:20:30:300:90:2. After uniform mixing, the mixture is three-roll milled to a coating thickness of 2 μm. After drying to a thickness of 40 μm, the next stage begins. In the working layer, the mass ratio of mixed reinforcing material, hollow microspheres, coated zirconium boride, fluorine-modified silica, ethanol, and isopropanol is 30:5:8:15:360:50. After uniform mixing, the mixture is ground using a three-roll mill, and the spray thickness is 130 μm. Then, low-temperature pre-firing and sintering are performed. The low-temperature pre-firing involves heating to 600℃ at a heating rate of 5℃ / min and holding for 1.5 hours. After holding, the temperature is cooled to room temperature. The sintering is performed by spark plasma sintering. During the sintering process, an axial pressure of 20 MPa is applied, the temperature is raised to 1320℃, and the holding time is 7 minutes. The temperature is then cooled to room temperature with the furnace to obtain a special refractory and anti-adhesion ceramic coating for boron nitride side sealing plates used in thin strip continuous casting.

[0063] Example 3

[0064] This embodiment provides a special refractory and anti-adhesion ceramic coating for boron nitride side sealing plates used in thin strip continuous casting and its preparation method. The preparation method specifically includes the following steps:

[0065] S1, 75g of tetraethoxysilane was mixed with 280g of an ethanol-water solution, wherein the volume ratio of ethanol to deionized water in the ethanol-water solution was 3:2. The pH was adjusted to 3.5, and the mixture was stirred at room temperature for 110 min to obtain a silica sol. 65g of aluminum isopropoxide was dispersed in 95g of ethanol and stirred to obtain an aluminum sol. The silica sol and aluminum sol were then added sequentially to 500g of [unclear - possibly a specific ingredient or solution]. In a PMMA dispersion, the mass ratio of PMMA microspheres to deionized water is 1:10. The mixture is stirred and coated for 230 min, centrifuged, washed, and dried. The dried PMMA microspheres are then immersed in 145 g of boron solution for 160 min, where the mass ratio of boric acid to ethanol is 4:25. After drying, coated microspheres are obtained. These coated microspheres are then placed in an electric resistance furnace under air atmosphere and heated to 750 °C for 170 min to obtain hollow spheres. The hollow spheres are then immersed in 200 g of 0.1 mol / L cerium nitrate solution for 195 min, dried, and placed in an electric resistance furnace. The temperature is then raised to 1320 °C and held for 270 min. After cooling to room temperature, the microspheres are pulverized and sieved to obtain hollow microspheres.

[0066] S2, 65g of zirconium boride and 10g of silicon dioxide were added to 250g of anhydrous ethanol and mixed evenly to obtain a suspension. 10g of aluminum nitrate nonahydrate was dispersed in 100g of deionized water to obtain an aluminum nitrate solution. Phosphoric acid was then added to the aluminum nitrate solution to adjust the pH to 2.5 to obtain an aluminum phosphorus solution. The aluminum phosphorus solution was added to the suspension and the mixture was stirred for 230min. After centrifugation, washing, and drying, the mixture was kept at 720℃ for 115min to obtain coated zirconium boride.

[0067] S3, 58g of hexagonal boron nitride was dispersed in 220g of anhydrous isopropanol and sonicated for 32h under ice bath conditions. After sonication, the supernatant was collected by centrifugation. After centrifugation, washing, and drying of the supernatant, boron nitride flakes were obtained. 22g of boron nitride flakes and 28g of SiC nanowires were dispersed in 200g of isopropanol and mixed evenly. The length of the SiC nanowires was 50-100μm and the diameter was <500nm. Then, 3.5g of 3-aminopropyltriethoxysilane was added to the isopropanol and stirred for 65min. After filtration, washing, and drying, the mixed reinforcing material was obtained.

[0068] S4, the boron nitride side sealing plate is sequentially coated with a bonding layer, a functional layer, and a working layer. In the bonding layer, the mass ratio of hexagonal boron nitride powder, hollow microspheres, coated zirconium boride, alumina powder, 3-aminopropyltrimethoxysilane, ethanol, and isopropanol is 250:12:8:55:6:320:100. After uniform mixing, it is three-roll milled to a coating thickness of 75 μm. After drying, it proceeds to the next stage. In the functional layer, the mass ratio of hexagonal boron nitride powder, hollow microspheres, coated zirconium boride, silica nanoparticles, mixed reinforcing material, alumina powder, ethanol, isopropanol, and barium carbonate is 190:32:28:11:18:38:320:60:4. After uniform mixing, it is three-roll milled to a coating thickness of 2 μm. After drying to a thickness of 30 μm, the next stage begins. In the working layer, the mass ratio of mixed reinforcing material, hollow microspheres, coated zirconium boride, fluorine-modified silica, ethanol, and isopropanol is 28:6:11:14:320:60. After uniform mixing, the mixture is ground using a three-roll mill, and the spray thickness is 140 μm. Then, low-temperature pre-firing and sintering are performed. The low-temperature pre-firing involves heating to 750°C at a heating rate of 5°C / min and holding for 1.2 hours. After holding, the temperature is cooled to room temperature. The sintering is performed by spark plasma sintering. During the sintering process, an axial pressure of 22 MPa is applied, the temperature is raised to 1260°C, and the holding time is 9 minutes. The temperature is then cooled to room temperature with the furnace to obtain a special refractory and anti-adhesion ceramic coating for boron nitride side sealing plates used in thin strip continuous casting.

[0069] Example 4

[0070] This embodiment provides a special refractory and anti-adhesion ceramic coating for boron nitride side sealing plates used in thin strip continuous casting and its preparation method. The preparation method specifically includes the following steps:

[0071] S1, 65g of tetraethoxysilane was mixed with 260g of an ethanol-water solution, wherein the volume ratio of ethanol to deionized water in the ethanol-water solution was 3:2. The pH was adjusted to 3.2, and the mixture was stirred at room temperature for 105 min to obtain a silica sol. 60g of aluminum isopropoxide was dispersed in 90g of ethanol and stirred to obtain an aluminum sol. The silica sol and aluminum sol were then added sequentially to 500g of [unclear - possibly a specific ingredient or solution]. In a PMMA dispersion, the mass ratio of PMMA microspheres to deionized water is 1:10. The mixture is stirred and coated for 210 min, centrifuged, washed, and dried. The dried PMMA microspheres are then immersed in 145 g of boron solution for 170 min, where the mass ratio of boric acid to ethanol is 4:25. After drying, coated microspheres are obtained. The coated microspheres are then placed in an electric resistance furnace under air atmosphere and heated to 800℃ for 160 min to obtain hollow spheres. The hollow spheres are then immersed in 200 g of 0.1 mol / L cerium nitrate solution for 185 min. After drying, the hollow spheres are placed in an electric resistance furnace and heated to 1380℃ for 280 min. After cooling to room temperature, the spheres are pulverized and sieved to obtain hollow microspheres.

[0072] S2, 75g of zirconium boride and 12g of silicon dioxide were added to 250g of anhydrous ethanol and mixed evenly to obtain a suspension. 12g of aluminum nitrate nonahydrate was dispersed in 100g of deionized water to obtain an aluminum nitrate solution. Phosphoric acid was added to the aluminum nitrate solution to adjust the pH to 2 to obtain an aluminum phosphorus solution. The aluminum phosphorus solution was added to the suspension and stirred for 210min. After centrifugation, washing, and drying, the solution was kept at 780℃ for 105min to obtain coated zirconium boride.

[0073] S3, 52g of hexagonal boron nitride was dispersed in 280g of anhydrous isopropanol and sonicated for 35h under ice bath conditions. After sonication, the supernatant was collected by centrifugation. After centrifugation, washing, and drying of the supernatant, boron nitride flakes were obtained. 28g of boron nitride flakes and 22g of SiC nanowires were dispersed in 200g of isopropanol and mixed evenly. The length of the SiC nanowires was 50-100μm and the diameter was <500nm. Then 2.5g of 3-aminopropyltriethoxysilane was added to the isopropanol and stirred for 75min. After filtration, washing, and drying, the mixed reinforcing material was obtained.

[0074] S4, the boron nitride side sealing plate is sequentially coated with a bonding layer, a functional layer, and a working layer. In the bonding layer, the mass ratio of hexagonal boron nitride powder, hollow microspheres, coated zirconium boride, alumina powder, 3-aminopropyltrimethoxysilane, ethanol, and isopropanol is 220:18:9:45:7:360:120. After uniform mixing, it is three-roll milled to a coating thickness of 70 μm. After drying, it proceeds to the next stage. In the functional layer, the mass ratio of hexagonal boron nitride powder, hollow microspheres, coated zirconium boride, silica nanoparticles, mixed reinforcing material, alumina powder, ethanol, isopropanol, and barium carbonate is 170:38:32:9:12:32:350:80:6. After uniform mixing, it is three-roll milled to a coating thickness of 2 μm. After drying to a thickness of 10 μm, the next stage begins. In the working layer, the mass ratio of mixed reinforcing material, hollow microspheres, coated zirconium boride, fluorine-modified silica, ethanol, and isopropanol is 22:9:9:11:350:80. After uniform mixing, the mixture is ground using a three-roll mill, and the spray thickness is 150 μm. Then, low-temperature pre-firing and sintering are performed. The low-temperature pre-firing involves heating to 650°C at a heating rate of 5°C / min and holding for 1.4 hours. After holding, the temperature is cooled to room temperature. The sintering is performed by spark plasma sintering. During the sintering process, an axial pressure of 28 MPa is applied, the temperature is raised to 1300°C, and the holding time is 8 minutes. The temperature is then cooled to room temperature with the furnace to obtain a special refractory and anti-adhesion ceramic coating for boron nitride side sealing plates used in thin strip continuous casting.

[0075] Comparative Example 1

[0076] This comparative example provides a special refractory and anti-adhesion ceramic coating for boron nitride side sealing plates used in thin strip continuous casting and its preparation method. The difference between this example and Example 1 is that hollow microspheres are not added to the bonding layer, functional layer and working layer. Other process parameters and operating conditions are exactly the same as in Example 1.

[0077] Comparative Example 2

[0078] This comparative example provides a special refractory and anti-adhesion ceramic coating for boron nitride side sealing plates used in thin strip continuous casting and its preparation method. The difference between this example and Example 1 is that no zirconium boride coating is added to the bonding layer, functional layer and working layer. Other process parameters and operating conditions are exactly the same as in Example 1.

[0079] Comparative Example 3

[0080] This comparative example provides a special refractory and anti-adhesion ceramic coating for boron nitride side sealing plates used in thin strip continuous casting and its preparation method. The difference between this example and Example 1 is that no mixed reinforcing material is added to either the functional layer or the working layer. Other process parameters and operating conditions are exactly the same as in Example 1.

[0081] Comparative Example 4

[0082] This comparative example provides a special refractory and anti-adhesion ceramic coating for boron nitride side sealing plates used in thin strip continuous casting and its preparation method. The difference between this example and Example 1 is that the total mass and proportion of the raw materials for the bonding layer, functional layer and working layer are kept unchanged and mixed together to prepare a single slurry. The single slurry is then coated to the same thickness as in Example 1 in one go. Other process parameters and operating conditions are exactly the same as in Example 1.

[0083] Performance testing: The performance of the special refractory and anti-adhesion ceramic coatings for boron nitride side sealing plates for thin strip continuous casting prepared in Examples 1-4 and Comparative Examples 1-4 were tested according to the following methods.

[0084] Thermal shock resistance test method: Place the boron nitride side sealing plate (length and width dimensions 20mm×20mm) coated with anti-adhesion coating in a resistance furnace, heat it to 1100℃ at 10℃ / min, and hold it at that temperature for 30min. After the holding time, force-cool the boron nitride side sealing plate with air until it cools to below 40℃. This is recorded as one thermal cycle. After the sample has completely cooled, carefully examine the coating surface with a microscope to observe for any cracks. Place the inspected sample back into the furnace and start the next thermal cycle. After the defect inspection of each cycle, determine whether the sample has failed according to the following criteria: any crack with a single length exceeding 1mm that is visible to the naked eye on the coating surface, or any size of coating peeling. Once the sample is determined to be failed, stop the subsequent thermal cycling and record the final number of failure cycles. Each group should have at least 3 parallel samples. Calculate the average number of failure cycles and record it as the cycle number.

[0085] Test method for coating resistance to (static) corrosion: Place a sufficient amount of low-carbon steel block into a crucible, and then completely embed a boron nitride side sealing plate (length and width dimensions of 10mm×10mm) coated with an anti-adhesion coating in the middle of the steel block, ensuring that the sample is surrounded by the steel block. The initial mass of the boron nitride side sealing plate coated with the anti-adhesion coating is recorded as m0. The temperature is increased to 1550℃ at a rate of 10℃ / min and held at a constant temperature for 2 hours. After the holding time is completed, the heating power is turned off, and the sample is allowed to cool to room temperature in an argon atmosphere. The solidified steel ingot is removed, and the steel ingot is carefully cut along the sample contour using a metallographic cutting machine to completely remove the encased sample. During the operation, damage to the sample surface should be avoided as much as possible. Large pieces of adhered metal on the sample surface are removed mechanically. The sample is ultrasonically cleaned in acetone and ethanol to remove oil and loose adhering substances. After drying, it is cooled to room temperature, and its final mass m1 is weighed. The mass change rate = (m1-m0) / m0×100%.

[0086] The test results are shown in Table 1.

[0087] Table 1. Test results of the special refractory and anti-adhesion ceramic coating for boron nitride side sealing plates for thin strip continuous casting prepared in Examples 1-4 and Comparative Examples 1-4.

[0088] Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Number of loops (times) 38 41 40 42 21 32 34 17 Quality change rate (%) +0.72 +0.76 +0.68 +0.74 -2.33 -6.48 -2.86 +6.48

[0089] As shown in Table 1, compared to Example 1, Comparative Example 1 had a lower number of cycles and a higher absolute value of the mass change rate; Comparative Example 2 had a lower number of cycles and a higher absolute value of the mass change rate; Comparative Example 3 had a lower number of cycles and a higher absolute value of the mass change rate; and Comparative Example 4 had a lower number of cycles and a higher absolute value of the mass change rate. This is because Comparative Example 1 lacked hollow microspheres, resulting in a coating that lacked thermal stress buffering and insulation capabilities. Thermal shock directly acted on the dense coating, leading to a decrease in the number of cycles. The thermal stress generated in the local coating caused micro-scraping, resulting in an increase in the absolute value of the mass change rate. Comparative Example 2 lacked coated zirconium boride, which prevented the generation of a low-melting-point phase to fill the microcracks in time, thus resulting in a decrease in the number of cycles and an increase in the absolute value of the mass change rate. Comparative Example 3 lacked mixed reinforcing material, resulting in poor coating toughness. Microcracks generated by thermal stress would rapidly expand into macroscopic failure cracks or coating spalling, thus resulting in a decrease in the number of cycles and an increase in the absolute value of the mass change rate. Comparative Example 4 is a single-layer structure. There is a thermal expansion mismatch between the coating and the substrate, which leads to stress concentration, easy peeling at the coating interface, a decrease in the number of cycles, low density, easy penetration of molten steel, internal reaction and weight gain, and an increased rate of mass change.

[0090] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preparing a special refractory and anti-adhesion ceramic coating for boron nitride side sealing plates used in thin strip continuous casting, characterized in that, The preparation method includes: S1, a silica sol is obtained by mixing tetraethoxysilane with an aqueous ethanol solution, aluminum isopropoxide is dispersed in ethanol to obtain an aluminum sol, the silica sol and aluminum sol are added sequentially to a PMMA dispersion, and then immersed in a boron solution to obtain coated microspheres, the coated microspheres are kept warm to obtain hollow spheres, the hollow spheres are immersed in a cerium nitrate solution, dried and kept warm to obtain hollow microspheres; S2, zirconium boride and silicon dioxide are added to anhydrous ethanol to obtain a suspension, aluminum nitrate nonahydrate is dispersed in deionized water to obtain an aluminum nitrate solution, phosphoric acid is added to the aluminum nitrate solution to obtain an aluminum phosphorus solution, and the aluminum phosphorus solution is added to the suspension to obtain coated zirconium boride. S3, hexagonal boron nitride is dispersed in anhydrous isopropanol and ultrasonicated to obtain boron nitride flakes. The boron nitride flakes and SiC nanowires are dispersed in isopropanol, and then 3-aminopropyltriethoxysilane is added to isopropanol and stirred to obtain a mixed reinforcing material. S4. The boron nitride side sealing plate is coated with a bonding layer, a functional layer and a working layer in sequence, and then pre-fired and sintered at low temperature to obtain a special fire-resistant and anti-adhesion ceramic coating for boron nitride side sealing plate for thin strip continuous casting.

2. The method for preparing a special refractory and anti-adhesion ceramic coating for boron nitride side sealing plates for thin strip continuous casting according to claim 1, characterized in that, In S1: The mass ratio of the tetraethoxysilane, aqueous ethanol solution, aluminum isopropoxide, ethanol, PMMA dispersion, boron solution and cerium nitrate solution is (60-80):(250-300):(50-70):(80-100):500:145:

200.

3. The method for preparing a special refractory and anti-adhesion ceramic coating for boron nitride side sealing plates used in thin strip continuous casting according to claim 1, characterized in that, In S2: The mass ratio of zirconium boride, silicon dioxide, anhydrous ethanol, aluminum nitrate nonahydrate, and deionized water is (60-80):(8-15):250:(8-15):

100.

4. The method for preparing a special refractory and anti-adhesion ceramic coating for boron nitride side sealing plates for thin strip continuous casting according to claim 1, characterized in that, In S3: The mass ratio of hexagonal boron nitride to anhydrous isopropanol is (50-60):(200-300).

5. The method for preparing a special refractory and anti-adhesion ceramic coating for boron nitride side sealing plates for thin strip continuous casting according to claim 1, characterized in that, In S3: The mass ratio of the boron nitride sheet, SiC nanowires, isopropanol and 3-aminopropyltriethoxysilane is (20-30):(20-30):200:(2-4); The SiC nanowires have a length of 50-100 μm and a diameter of <500 nm.

6. The method for preparing a special refractory and anti-adhesion ceramic coating for boron nitride side sealing plates used in thin strip continuous casting according to claim 1, characterized in that, In S4: In the bonding layer, the mass ratio of hexagonal boron nitride powder, hollow microspheres, coated zirconium boride, alumina powder, 3-aminopropyltrimethoxysilane, ethanol and isopropanol is (200-260):(10-20):(5-10):(40-60):(5-8):(300-380):(80-140). After being mixed evenly, the mixture is ground with three rollers, and the spraying thickness is 60-80μm. After drying, it proceeds to the next stage.

7. The method for preparing a special refractory and anti-adhesion ceramic coating for boron nitride side sealing plates used in thin strip continuous casting according to claim 1, characterized in that, In S4: In the functional layer, the mass ratio of hexagonal boron nitride powder, hollow microspheres, coated zirconium boride, silica nanoparticles, mixed reinforcing material, alumina powder, ethanol, isopropanol and barium carbonate is (160-200):(30-40):(25-35):(8-12):(10-20):(30-40):(300-360):(50-90):(2-8). After being mixed evenly, the mixture is ground with three rollers, and the coating thickness is 200-240μm. After drying, it proceeds to the next stage.

8. The method for preparing a special refractory and anti-adhesion ceramic coating for boron nitride side sealing plates for thin strip continuous casting according to claim 1, characterized in that, In S4: In the working layer, the mass ratio of the mixed reinforcing material, hollow microspheres, coated zirconium boride, fluorinated silica, ethanol and isopropanol is (20-30):(5-10):(8-12):(10-15):(300-360):(50-90). After being mixed evenly, the mixture is ground with three rollers, and the coating thickness is 130-160μm.

9. The method for preparing a special refractory and anti-adhesion ceramic coating for boron nitride side sealing plates used in thin strip continuous casting according to claim 1, characterized in that, In S4: The low-temperature preheating process involves heating to 600-800℃ at a heating rate of 5℃ / min and holding at that temperature for 1-1.5 hours, followed by cooling to room temperature after the holding period. The sintering is spark plasma sintering, in which an axial pressure of 20-30 MPa is applied, the temperature is raised to 1250-1320℃, the holding time is 7-10 min, and the furnace is cooled to room temperature.

10. A special refractory and anti-adhesion ceramic coating for boron nitride side sealing plates used in thin strip continuous casting, obtained by the preparation method according to any one of claims 1-9.