Normal-temperature curing high-temperature and high-radiation coating and preparation method thereof

Abstract

This invention discloses a room-temperature curing high-temperature, high-emissivity coating, formed by spraying a coating containing fillers and a film-forming agent. The fillers include black silicon carbide, molybdenum silicide, and praseodymium oxide-modified tantalum silicide. The film-forming agent is polysiloxane reinforced with nano-silicon carbide whiskers. The filler content in the coating is 70%–80% by mass. This invention also discloses a method for preparing the above-mentioned room-temperature curing high-temperature, high-emissivity coating, comprising uniformly mixing the film-forming agent, fillers, and organic solvent to obtain a coating; spraying the coating onto the surface of a substrate and curing at room temperature for 48–72 hours to obtain the room-temperature curing high-temperature, high-emissivity coating. The high-temperature, high-emissivity coating of this invention can be prepared at room temperature and used at high temperatures, with a maximum operating temperature of 1650℃ and a high-temperature emissivity of 0.88–0.90, which has important guiding significance for the research of high-temperature radiation heat dissipation coatings.

Description

Technical Field

[0001] This invention belongs to the field of high temperature and high radiation coating technology, and relates to a coating, particularly a room temperature curing high temperature and high radiation coating and its preparation method. Background Technology

[0002] High-temperature, high-emissivity coatings possess strong radiative heat transfer capabilities at high temperatures and are widely used in aerospace, kiln insulation, infrared thermometry, and environmental protection and energy conservation. The high-temperature emissivity of such coatings is generally required to be no less than 0.80, with high-emissivity coatings exhibiting excellent radiative heat transfer performance typically having an emissivity above 0.85. High-temperature, high-emissivity coatings offer advantages such as thinness, light weight, and high weight-to-heat transfer efficiency.

[0003] Currently, high-temperature, high-emissivity coatings with operating temperatures reaching 1650℃ require either thermal spraying (e.g., the hafnium carbide coating on the X-43) or high-temperature sintering (e.g., the HETC coating on the X-37B wing leading edge is sintered at 1200℃). Thermal spraying is highly dependent on equipment, and high-temperature sintering is complex; neither is suitable for large-area coating fabrication, especially since repairs are difficult after impact damage. Therefore, a high-temperature, high-emissivity coating that can be fabricated over large areas using air spraying, cures at room temperature, and can be directly applied at high temperatures is needed. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned defects and provide a room-temperature curing high-temperature, high-emissivity coating and its preparation method, solving the technical problems of existing high-temperature, high-emissivity coatings being highly dependent on equipment and having complex preparation processes. The high-temperature, high-emissivity coating of this invention can be prepared at room temperature and used at high temperatures, with a maximum operating temperature of 1650℃ and a high-temperature emissivity of 0.87-0.90, which has important guiding significance for the research of high-temperature radiation heat dissipation coatings.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] This invention discloses a room-temperature curing, high-temperature, high-emissivity coating. The coating uses a room-temperature curing ceramic precursor resin as the film-forming material and a mixture of 90%–98% pure black silicon carbide, praseodymium oxide-modified tantalum silicide, and molybdenum silicide as the high-temperature, high-emissivity filler. This room-temperature curing, high-temperature, high-emissivity coating can be prepared at room temperature and used at high temperatures, with a maximum operating temperature of 1650℃ and a high-temperature emissivity of 0.87–0.90. It can be prepared on the surfaces of metals, ceramics, and composite materials using conventional air spraying and brushing processes, which are simple to implement. It maintains its organic coating state below 400℃, exhibits good flexibility, and has good mechanical compatibility with the substrate. When the coating suffers impact damage, it can be repaired at room temperature using air spraying or brushing processes, which are simple to implement, ensuring good structural and functional integrity under various operating environments. This coating can be used on the surfaces of various high-temperature products, meeting their high-temperature radiation heat dissipation requirements up to 1650℃, effectively reducing the surface temperature of the product, minimizing heat transfer from the surface to the interior, and ensuring normal internal temperature.

[0007] A high-temperature, high-emissivity coating that cures at room temperature is formed by spraying a coating containing fillers and film-forming agents.

[0008] The fillers include black silicon carbide, molybdenum silicide, and praseodymium oxide-modified tantalum silicide;

[0009] The film-forming material is polysiloxane reinforced with nano-silicon carbide whiskers;

[0010] The filler content in the coating is 70% to 80% by mass.

[0011] Furthermore, the mass percentage of each component in the packing is as follows:

[0012] Black silicon carbide 20%–40%;

[0013] Molybdenum silicide 20%–40%;

[0014] Praseodymium oxide-modified tantalum silicide accounts for 40%–60%.

[0015] Furthermore, the preparation method of praseodymium oxide modified tantalum silicide includes:

[0016] An aqueous solution containing praseodymium compounds is mixed thoroughly with tantalum silicide to obtain a mixture; the praseodymium-containing compounds include one of praseodymium sulfate, praseodymium nitrate, or praseodymium chloride;

[0017] The mixture is dried at 100–150°C for 3–5 hours, and then sintered at 900–1200°C for 4–8 hours.

[0018] Furthermore, the molar ratio of praseodymium in the praseodymium-containing compound to tantalum in tantalum silicide is 1:8 to 10;

[0019] In aqueous solutions containing praseodymium compounds, the molar concentration of praseodymium is 0.08–0.12 mol / L.

[0020] Furthermore, the purity of black silicon carbide is 90%–98%.

[0021] Furthermore, in the polysiloxane reinforced with nano-silicon carbide whiskers, the nano-silicon carbide whiskers are β-nano-silicon carbide whiskers, and the mass percentage of nano-silicon carbide whiskers is 5% to 15%.

[0022] Furthermore, the coating thickness is 50–150 μm;

[0023] The coating is cured at room temperature and has an emissivity of ≥0.87 at 600–1000℃.

[0024] The above-mentioned method for preparing a room-temperature curing, high-temperature, high-emissivity coating includes:

[0025] The coating is obtained by uniformly mixing the film-forming material, filler and organic solvent;

[0026] The coating is sprayed onto the substrate surface and cured at room temperature for 48–72 hours to obtain a high-temperature, high-emissivity coating that cures at room temperature.

[0027] Furthermore, the organic solvent in the coating accounts for 40% to 60% by mass;

[0028] The organic solvent is butyl acetate or a mixture of butyl acetate and ethyl acetate.

[0029] Furthermore, when the ambient temperature during spraying is below 15°C, the mass percentage of butyl acetate in the organic solvent is 60%–80%.

[0030] When the ambient temperature during spraying is above 15°C, the mass percentage content of butyl acetate in the organic solvent is 80%–100%.

[0031] Compared with the prior art, the present invention has at least one of the following advantages:

[0032] (1) The high temperature and high radiation coating of the present invention can be prepared at room temperature and used at high temperature. The maximum operating temperature reaches 1650℃ and the high temperature emissivity reaches 0.87-0.90. The preparation process is simple and can meet the high temperature radiation heat dissipation requirements of military and civilian fields.

[0033] (2) This invention significantly improves the high-temperature oxidation resistance of tantalum silicide by modifying it with praseodymium oxide, making the high-temperature emissivity of tantalum silicide more stable and its service life longer;

[0034] (3) The present invention maintains the organic coating state below 400℃, has good flexibility, and good mechanical compatibility with the substrate. When the coating is damaged by impact, it can be repaired at room temperature by air spraying, brushing, or other processes. The repair process is simple, enabling it to maintain good structural and functional integrity in various usage environments. Attached Figure Description

[0035] Figure 1 This is a flowchart illustrating the preparation process of the high-temperature, high-emissivity coating that cures at room temperature according to the present invention.

[0036] Figure 2 This is the high-temperature emissivity curve of the high-temperature, high-emissivity coating that cures at room temperature according to the present invention;

[0037] Figure 3 The images show the SEM morphology of the high-temperature, high-emissivity coating of the present invention after being cured at room temperature for 10 minutes at 1650℃. (a) morphology magnified 200 times, (b) morphology magnified 2000 times, (c) morphology magnified 5000 times, and (d) morphology magnified 10000 times. Detailed Implementation

[0038] The features and advantages of the present invention will become clearer and more apparent from the following detailed description.

[0039] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments. Although various aspects of embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

[0040] This invention provides a high-temperature, high-emissivity coating that can be prepared over large areas by air spraying, is room-temperature curable, and can be directly applied at high temperatures. The coating uses high-temperature, high-emissivity fillers such as praseodymium oxide-modified tantalum silicide. Tantalum silicide is the core high-emissivity filler that achieves high temperature and high emissivity at 1650℃. Through praseodymium oxide coating modification, the high-temperature oxidation resistance of tantalum silicide is significantly improved, making the high-temperature emissivity of tantalum silicide more stable and extending its service life. At the same time, this coating has the advantages of simple large-area preparation process, room-temperature curing, direct application at high temperatures, and easy repair, which can meet the high-temperature radiation heat dissipation requirements of military and civilian fields.

[0041] In the room-temperature curing high-temperature high-emissivity coating of the present invention, the coating forming the high-emissivity coating includes fillers and film-forming materials, wherein the fillers are a mixture of black silicon carbide, praseodymium oxide-modified tantalum silicide and molybdenum silicide with a purity of 90% to 98%; the film-forming material is polysiloxane reinforced with nano-silicon carbide whiskers; the mass percentage of fillers in the coating is 70% to 80%.

[0042] In one specific embodiment, the mass percentage of each component in the mixture of black silicon carbide, praseodymium oxide-modified tantalum silicide, and molybdenum silicide with a purity of 90% to 98% is as follows: praseodymium oxide-modified tantalum silicide 40% to 60%, molybdenum silicide 20% to 40%, and black silicon carbide 20% to 40%.

[0043] In one specific embodiment, praseodymium oxide-modified tantalum silicide is prepared by uniformly mixing tantalum silicide with an aqueous solution of one of praseodymium sulfate, praseodymium nitrate, or praseodymium chloride, then drying at 100–150°C for 4 hours, and finally sintering at 1000°C for 6 hours. After sintering, the praseodymium sulfate, praseodymium nitrate, or praseodymium chloride forms a praseodymium oxide coating on the surface of tantalum silicide. This praseodymium oxide coating not only prevents tantalum silicide from contacting oxygen, reducing its oxidation, but also reacts with the surrounding silicon oxide formed at high temperatures by the siloxane resin and the small amount of silicon oxide generated by the oxidation of tantalum silicide, forming a dense rare-earth silicate structure. This further prevents the oxidation of tantalum silicide, significantly improving its high-temperature oxidation resistance, making its high-temperature emissivity more stable, and extending its service life.

[0044] In one specific embodiment, the molar ratio of praseodymium in praseodymium sulfate, praseodymium nitrate, or praseodymium chloride to tantalum in tantalum silicide is 1:9, and the molar concentration of praseodymium in the aqueous solution of praseodymium sulfate, praseodymium nitrate, or praseodymium chloride is 0.1 mol / L.

[0045] In one specific embodiment, the mass percentage of each component in the polysiloxane reinforced with nano-silicon carbide whiskers is as follows: the nano-silicon carbide whiskers are β-nano-silicon carbide whiskers, accounting for 5% to 15% of the total mass of the polysiloxane reinforced with nano-silicon carbide whiskers, with an optimal range of 8% to 12%.

[0046] The thickness of the high-emissivity coating prepared by this invention is 50–150 μm, with the optimal range being 60–120 μm.

[0047] like Figure 1 The diagram shows the preparation process of the room-temperature curing, high-temperature, and high-radiation coating of the present invention. The specific preparation method of the room-temperature curing, high-temperature, and high-radiation coating of the present invention includes the following steps:

[0048] First, nano-silicon carbide whiskers are mixed with polysiloxane resin and dispersed at high speed for 1-3 hours. Then, praseodymium oxide-modified tantalum silicide, molybdenum silicide, black silicon carbide and other fillers and organic solvents are mixed by high-speed stirring, ball milling or sand milling for 4-6 hours. The uniformly mixed coating is sprayed onto the surface of the substrate to be coated and then cured at room temperature for 48-72 hours. The organic solvent is a mixture of butyl acetate and ethyl acetate.

[0049] In one specific embodiment, the organic solvent content in the uniformly mixed coating is 40% to 60% by mass.

[0050] In one specific embodiment, the mass percentage content of butyl acetate in the mixed solvent is 60% to 100%. When the spraying ambient temperature is below 15°C, the mass percentage content of butyl acetate in the mixed solvent is 60% to 80%, and when the spraying ambient temperature is above 15°C, the mass percentage content of butyl acetate in the mixed solvent is 80% to 100%.

[0051] Example 1

[0052] First, silicon carbide whiskers with a content of 12% were mixed with polysiloxane resin and dispersed at high speed for 2 hours to prepare reinforced polysiloxane. Then, a high-temperature, high-emissivity coating was prepared, with the following raw material ratio (mass percentage content):

[0053] The coating contains 40 wt% organic solvents and 60 wt% coating raw materials;

[0054] The organic solvents are 70 wt% butyl acetate and 30 wt% ethyl acetate;

[0055] The coating material contains 25 wt% reinforced polysiloxane and 75 wt% solid filler; the solid filler contains 60 wt% praseodymium oxide modified tantalum silicide, 20 wt% molybdenum silicide, and 20 wt% black silicon carbide.

[0056] All raw materials were ball-milled and mixed for 3 hours to form a uniform slurry.

[0057] Then, in an environment below 15°C, an air spraying process is used to prepare a coating on substrates such as quartz composite materials, alumina composite materials, carbon-carbon composite materials, or porous ceramic insulation materials.

[0058] Finally, the high-emissivity coating was left at room temperature for 60 hours. The resulting coating thickness was 110 μm.

[0059] The preparation methods of praseodymium oxide modified tantalum silicide include:

[0060] An aqueous solution of praseodymium chloride was mixed evenly with tantalum silicide, dried at 120°C for 5 hours, and then sintered at 1200°C for 4 hours. The molar ratio of praseodymium in praseodymium chloride to tantalum in tantalum silicide was 1:10, and the molar concentration of praseodymium in the aqueous solution of praseodymium chloride was 0.10 mol / L.

[0061] This high-temperature, high-emissivity coating has an emissivity of 0.88 at 600℃ and 0.90 at 1000℃, with a maximum operating temperature of 1650℃. Figure 2 and Figure 3 As shown.

[0062] Example 2

[0063] First, silicon carbide whiskers with a content of 5% were mixed with polysiloxane resin and dispersed at high speed for 2 hours to prepare reinforced polysiloxane. Then, a high-temperature, high-emissivity coating was prepared, with the following raw material ratio (mass percentage content):

[0064] The coating contains 40 wt% organic solvents and 60 wt% coating raw materials;

[0065] The organic solvent is butyl acetate;

[0066] The coating material contains 20 wt% reinforced polysiloxane and 80 wt% solid filler; the solid filler contains 40 wt% praseodymium oxide modified tantalum silicide, 30 wt% molybdenum silicide, and 30 wt% black silicon carbide.

[0067] All raw materials were ball-milled and mixed for 4 hours to form a uniform slurry.

[0068] Then, in an environment above 15°C, an air spraying process is used to prepare a coating on substrates such as quartz composite materials, alumina composite materials, carbon-carbon composite materials, or porous ceramic insulation materials.

[0069] Finally, the sprayed high-emissivity coating was left at room temperature for 48 hours. The resulting coating thickness was 60 μm.

[0070] The preparation methods of praseodymium oxide modified tantalum silicide include:

[0071] An aqueous solution of praseodymium sulfate was mixed thoroughly with tantalum silicide, dried at 100°C for 4 hours, and then sintered at 1000°C for 6 hours. The molar ratio of praseodymium in praseodymium sulfate to tantalum in tantalum silicide was 1:9, and the molar concentration of praseodymium in the aqueous solution of praseodymium sulfate was 0.1 mol / L.

[0072] The high-temperature and high-emissivity coating obtained in this embodiment has an emissivity of 0.87 at 600℃, an emissivity of 0.88 at 1000℃, and a maximum operating temperature of 1650℃.

[0073] Example 3

[0074] First, silicon carbide whiskers with a content of 8% were mixed with polysiloxane resin and dispersed at high speed for 2 hours to prepare reinforced polysiloxane. Then, a high-temperature, high-emissivity coating was prepared, with the following raw material ratio (mass percentage content):

[0075] The coating contains 50 wt% organic solvent and 50 wt% coating raw material;

[0076] The organic solvent is butyl acetate;

[0077] The coating material contains 30 wt% reinforced polysiloxane and 70 wt% solid filler; the solid filler contains 50 wt% praseodymium oxide modified tantalum silicide, 30 wt% molybdenum silicide, and 20 wt% black silicon carbide.

[0078] All raw materials were ball-milled and mixed for 3 hours to form a uniform slurry.

[0079] Then, in an environment above 15°C, an air spraying process is used to prepare a coating on substrates such as quartz composite materials, alumina composite materials, carbon-carbon composite materials, or porous ceramic insulation materials.

[0080] Finally, the sprayed high-emissivity coating was left at room temperature for 48 hours. The resulting coating thickness was 150 μm.

[0081] The preparation methods of praseodymium oxide modified tantalum silicide include:

[0082] An aqueous solution of praseodymium nitrate was mixed thoroughly with tantalum silicide, dried at 150°C for 4 hours, and then sintered at 1200°C for 4 hours. The molar ratio of praseodymium in praseodymium nitrate to tantalum in tantalum silicide was 1:8, and the molar concentration of praseodymium in the aqueous solution of praseodymium nitrate was 0.12 mol / L.

[0083] The high-temperature and high-emissivity coating has an emissivity of 0.89 at 600℃, 0.88 at 1000℃, and a maximum operating temperature of 1650℃.

[0084] Example 4

[0085] First, silicon carbide whiskers with a content of 15% were mixed with polysiloxane resin and dispersed at high speed for 2 hours to prepare reinforced polysiloxane. Then, a high-temperature, high-emissivity coating was prepared, with the following raw material ratio (mass percentage content):

[0086] The coating contains 60 wt% organic solvent and 40 wt% coating raw materials;

[0087] The organic solvents are 60 wt% butyl acetate and 40 wt% ethyl acetate;

[0088] The coating material contains 30 wt% reinforced polysiloxane and 70 wt% solid filler; the solid filler contains 50 wt% praseodymium oxide modified tantalum silicide, 25 wt% molybdenum silicide, and 25 wt% black silicon carbide.

[0089] All raw materials were ball-milled and mixed for 5 hours to form a uniform slurry.

[0090] Then, in an environment below 15°C, an air spraying process is used to prepare a coating on substrates such as quartz composite materials, alumina composite materials, carbon-carbon composite materials, or porous ceramic insulation materials.

[0091] Finally, the sprayed high-emissivity coating was left at room temperature for 72 hours. The resulting coating thickness was 100 μm.

[0092] The preparation methods of praseodymium oxide modified tantalum silicide include:

[0093] An aqueous solution of praseodymium chloride was mixed evenly with tantalum silicide, dried at 120°C for 5 hours, and then sintered at 900°C for 8 hours. The molar ratio of praseodymium in praseodymium chloride to tantalum in tantalum silicide was 1:10, and the molar concentration of praseodymium in the aqueous solution of praseodymium chloride was 0.08 mol / L.

[0094] The high-temperature and high-emissivity coating has an emissivity of 0.87 at 600℃, 0.89 at 1000℃, and a maximum operating temperature of 1650℃.

[0095] Example 5

[0096] First, silicon carbide whiskers with a content of 12% were mixed with polysiloxane resin and dispersed at high speed for 1 hour to prepare reinforced polysiloxane. Then, a high-temperature, high-emissivity coating was prepared, with the following raw material ratio (mass percentage content):

[0097] The coating contains 45 wt% organic solvents and 55 wt% coating raw materials;

[0098] The organic solvents are 90 wt% butyl acetate and 10 wt% ethyl acetate;

[0099] The coating material contains 20 wt% reinforced polysiloxane and 80 wt% solid filler; the solid filler contains 60 wt% praseodymium oxide modified tantalum silicide, 20 wt% molybdenum silicide, and 20 wt% black silicon carbide.

[0100] All raw materials were ball-milled and mixed for 4 hours to form a uniform slurry.

[0101] Then, in an environment above 15°C, an air spraying process is used to prepare a coating on substrates such as quartz composite materials, alumina composite materials, carbon-carbon composite materials, or porous ceramic insulation materials.

[0102] Finally, the sprayed high-emissivity coating was left at room temperature for 72 hours. The resulting coating thickness was 80 μm.

[0103] The preparation methods of praseodymium oxide modified tantalum silicide include:

[0104] An aqueous solution of praseodymium nitrate was mixed thoroughly with tantalum silicide, dried at 100°C for 5 hours, and then sintered at 1000°C for 6 hours. The molar ratio of praseodymium in praseodymium nitrate to tantalum in tantalum silicide was 1:8, and the molar concentration of praseodymium in the aqueous solution of praseodymium nitrate was 0.10 mol / L.

[0105] The high-temperature and high-emissivity coating has an emissivity of 0.87 at 600℃, 0.88 at 1000℃, and a maximum operating temperature of 1650℃.

[0106] Example 6

[0107] First, silicon carbide whiskers with a content of 10% were mixed with polysiloxane resin and dispersed at high speed for 3 hours to prepare reinforced polysiloxane. Then, a high-temperature, high-emissivity coating was prepared, with the following raw material ratio (mass percentage content):

[0108] The coating contains 45 wt% organic solvents and 55 wt% coating raw materials;

[0109] The organic solvents are 90 wt% butyl acetate and 10 wt% ethyl acetate;

[0110] The coating material contains 20 wt% reinforced polysiloxane and 80 wt% solid filler; the solid filler contains 40 wt% praseodymium oxide modified tantalum silicide, 40 wt% molybdenum silicide, and 20 wt% black silicon carbide.

[0111] All raw materials were ball-milled and mixed for 4 hours to form a uniform slurry.

[0112] Then, in an environment above 15°C, an air spraying process is used to prepare a coating on substrates such as quartz composite materials, alumina composite materials, carbon-carbon composite materials, or porous ceramic insulation materials.

[0113] Finally, the sprayed high-emissivity coating was left at room temperature for 72 hours. The resulting coating thickness was 120 μm.

[0114] The preparation methods of praseodymium oxide modified tantalum silicide include:

[0115] An aqueous solution of praseodymium nitrate was mixed thoroughly with tantalum silicide, dried at 100°C for 5 hours, and then sintered at 1000°C for 6 hours. The molar ratio of praseodymium in praseodymium nitrate to tantalum in tantalum silicide was 1:8, and the molar concentration of praseodymium in the aqueous solution of praseodymium nitrate was 0.10 mol / L.

[0116] The high-temperature and high-emissivity coating has an emissivity of 0.87 at 600℃, 0.88 at 1000℃, and a maximum operating temperature of 1650℃.

[0117] Comparative Example 1:

[0118] Other conditions were the same as in Example 1, except that the praseodymium oxide-modified tantalum silicide in Example 1 was replaced with tantalum silicide. The resulting coating had an emissivity of 0.84 at 600°C, an emissivity of 0.85 at 1000°C, and a maximum operating temperature of 1650°C. A comparison between Comparative Example 1 and Example 1 shows that the praseodymium oxide-modified tantalum silicide used in this invention can effectively improve the emissivity of the coating.

[0119] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

[0120] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A high-temperature, high-emissivity coating that cures at room temperature, characterized in that, Formed by spraying a coating containing fillers and film-forming agents; The fillers include black silicon carbide, molybdenum silicide, and praseodymium oxide-modified tantalum silicide; The film-forming material is polysiloxane reinforced with nano-silicon carbide whiskers; The filler in the coating accounts for 70% to 80% by mass; The preparation methods of praseodymium oxide modified tantalum silicide include: An aqueous solution containing praseodymium compounds is mixed thoroughly with tantalum silicide to obtain a mixture; the praseodymium-containing compounds include one of praseodymium sulfate, praseodymium nitrate, or praseodymium chloride; The mixture is dried at 100–150°C for 3–5 hours, and then sintered at 900–1200°C for 4–8 hours.

2. The high-temperature, high-emissivity coating that cures at room temperature according to claim 1, characterized in that, The mass percentage of each component in the packing is as follows: Black silicon carbide 20%–40%; Molybdenum silicide 20%–40%; Praseodymium oxide-modified tantalum silicide accounts for 40%–60%.

3. The high-temperature, high-emissivity coating that cures at room temperature according to claim 1, characterized in that, The molar ratio of praseodymium in praseodymium compounds to tantalum in tantalum silicide is 1:8 to 10; In aqueous solutions containing praseodymium compounds, the molar concentration of praseodymium is 0.08–0.12 mol / L.

4. The high-temperature, high-emissivity coating that cures at room temperature according to claim 1, characterized in that, The purity of black silicon carbide is 90%–98%.

5. The high-temperature, high-emissivity coating that cures at room temperature according to claim 1, characterized in that, In polysiloxane reinforced with nano-silicon carbide whiskers, the nano-silicon carbide whiskers are β-nano-silicon carbide whiskers, and the mass percentage of nano-silicon carbide whiskers is 5% to 15%.

6. The high-temperature, high-emissivity coating that cures at room temperature according to claim 1, characterized in that, The coating thickness is 50–150 μm; The coating is cured at room temperature and has an emissivity of ≥0.87 at 600–1000℃.

7. A method for preparing a room-temperature curing, high-temperature, high-emissivity coating according to any one of claims 1-6, characterized in that, include: The coating is obtained by uniformly mixing the film-forming material, filler and organic solvent; The coating is sprayed onto the substrate surface and cured at room temperature for 48–72 hours to obtain a high-temperature, high-emissivity coating that cures at room temperature.

8. The method for preparing a room-temperature curing, high-temperature, high-emissivity coating according to claim 7, characterized in that, The organic solvent in the coating is 40% to 60% by mass; The organic solvent is butyl acetate or a mixture of butyl acetate and ethyl acetate.

9. The method for preparing a room-temperature curing, high-temperature, high-emissivity coating according to claim 8, characterized in that, When the ambient temperature during spraying is below 15°C, the mass percentage of butyl acetate in the organic solvent is 60%–80%. When the ambient temperature during spraying is above 15°C, the mass percentage content of butyl acetate in the organic solvent is 80%–100%.

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