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

Abstract

The invention discloses a normal-temperature curing high-temperature high-radiation coating which is formed by spraying a coating containing a filler and a film forming matter, the filler comprises black silicon carbide, molybdenum silicide and praseodymium oxide modified tantalum silicide; the film forming matter is nano silicon carbide whisker reinforced polysilazane; and the mass percent of the filler in the coating is 70-80%. The invention further discloses a preparation method of the normal-temperature-curing high-temperature high-radiation coating. The preparation method comprises the following steps: uniformly mixing the film forming matter, the filler and the organic solvent to obtain a coating; and spraying the coating on the surface of a base material, and curing at room temperature for 48-72 hours to obtain the room-temperature-cured high-temperature high-radiation coating. The high-temperature and high-radiation coating can be prepared at room temperature and used at high temperature, the highest use temperature reaches 1650 DEG C, the high-temperature emissivity reaches 0.88-0.90, and the high-temperature and high-radiation coating has important guiding significance in research of high-temperature radiation heat dissipation coatings.

Description

Technical Field

[0001] The invention belongs to the technical field of high-temperature and high-radiation coatings and relates to a coating, in particular to a room-temperature-cured high-temperature and high-radiation coating and a preparation method thereof. Background Art

[0002] High temperature and high radiation coatings have strong radiation heat transfer capabilities at high temperatures and are widely used in aerospace, furnace insulation, infrared temperature measurement, environmental protection and energy saving, etc. The high temperature emissivity of high temperature and high radiation coatings is generally required to be no less than 0.80, and the emissivity of high radiation coatings with good radiation heat transfer performance is generally above 0.85. High temperature and high radiation coatings have the advantages of thin thickness, light weight, and high weight-to-heat transfer efficiency.

[0003] At present, high-temperature and high-radiation coatings with a temperature of 1650℃ in use at home and abroad either need to be prepared by thermal spraying, such as the X-43's hafnium carbide high-temperature and high-radiation coatings prepared by thermal spraying, or need high-temperature sintering, such as the HETC high-temperature and high-radiation coating on the leading edge of the X-37B wing, which is prepared by high-temperature sintering at 1200℃. The thermal spraying preparation process is highly dependent on equipment, and the high-temperature sintering preparation process is complicated. Both are not suitable for large-scale coating preparation, especially when the coating is damaged by bumps and is difficult to repair. Therefore, there is a need for a high-temperature and high-radiation coating that can be prepared on a large area by air spraying, can be cured at room temperature, and can be directly applied at high temperature. Summary of the invention

[0004] The purpose of the present invention is to overcome the above defects and provide a room temperature curing high temperature and high radiation coating and its preparation method, which solves the technical problems of the existing high temperature and high radiation coatings being highly dependent on equipment and having complex preparation processes. The high temperature and high radiation coating of the present invention can be prepared at room temperature and used at high temperature, with a maximum use temperature of 1650°C 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] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The invention discloses a room temperature curing high temperature and high radiation coating, which uses a room temperature curing ceramic precursor resin as a coating film-forming material, and uses a mixture of black silicon carbide with a purity of 90% to 98%, praseodymium oxide modified tantalum silicide and molybdenum silicide as a high temperature and high radiation filler. The room temperature curing high temperature and high radiation coating can be prepared at room temperature and used at high temperature, with a maximum use temperature of 1650°C and a high temperature emissivity of 0.87-0.90. It can be prepared on the surface of metal, ceramic, and composite materials by conventional air spraying, brushing and other processes, and the preparation process is simple. It maintains an organic coating state below 400°C, has good flexibility, and has good mechanical matching with the substrate. When the coating is damaged by collision, it can be repaired at room temperature by air spraying, brushing and other processes, and the repair process is simple, so that it can maintain good structural and functional integrity under various use environments. The coating can be used on the surface of various high temperature products to meet their high temperature radiation heat dissipation needs within 1650°C, effectively reduce the surface temperature of the product, reduce the heat transfer from the surface of the product to its interior, and ensure the normal temperature inside the product.

[0007] A room temperature curing high temperature high radiation coating, formed by spraying a coating containing a filler and a film former;

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

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

[0010] The mass percentage of the filler in the coating is 70% to 80%.

[0011] Furthermore, the mass percentage of each component in the filler is:

[0012] Black silicon carbide 20% to 40%;

[0013] Molybdenum silicide 20% to 40%;

[0014] Praseodymium oxide modified tantalum silicide 40% to 60%.

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

[0016] The aqueous solution of the praseodymium compound is uniformly mixed with tantalum silicide to obtain a mixture; the praseodymium compound comprises one of praseodymium sulfate, praseodymium nitrate or praseodymium chloride;

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

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

[0019] In the aqueous solution containing the praseodymium compound, the molar concentration of praseodymium is 0.08 to 0.12 mol / L.

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

[0021] Furthermore, in the nano-silicon carbide whisker reinforced polysiloxazane, the nano-silicon carbide whisker is β-nano-silicon carbide whisker, and the mass percentage of the nano-silicon carbide whisker is 5% to 15%.

[0022] Further, the coating thickness is 50 to 150 μm;

[0023] The curing temperature of the coating is room temperature, and the emissivity at 600-1000°C is ≥0.87.

[0024] The above-mentioned method for preparing a room temperature curing high temperature and high radiation coating comprises:

[0025] The film-forming material, the filler and the organic solvent are uniformly mixed to obtain the coating;

[0026] The coating is sprayed on the surface of the substrate and cured at room temperature for 48 to 72 hours to obtain a room temperature cured high temperature and high radiation coating.

[0027] Furthermore, the mass percentage of the organic solvent in the coating is 40% to 60%;

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

[0029] Furthermore, when the spraying environment temperature is lower than 15°C, the mass percentage of butyl acetate in the organic solvent is 60% to 80%;

[0030] When the spraying environment temperature is higher than 15° C., the mass percentage content of butyl acetate in the organic solvent is 80% to 100%.

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

[0032] (1) The room temperature curing high temperature and high radiation coating of the present invention can be prepared at room temperature and used at high temperature, with the maximum use temperature reaching 1650°C and the high temperature emissivity reaching 0.87-0.90. The preparation process is simple and can meet the high temperature radiation heat dissipation requirements in military and civilian fields;

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

[0034] (3) The present invention maintains an organic coating state below 400°C, has good flexibility, and has good mechanical matching with the substrate. When the coating is damaged by collision, it can be repaired at room temperature by air spraying, brushing, etc. The repair process is simple, so that it can maintain good structural and functional integrity under various use environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a flow chart of the preparation of a room temperature curing high temperature and high radiation coating of the present invention;

[0036] Figure 2 The high temperature emissivity curve of the room temperature cured high temperature and high radiation coating of the present invention;

[0037] Figure 3 These are SEM morphology images of the room temperature cured high temperature and high radiation coating of the present invention after high temperature testing at 1650°C-10min, wherein (a) is a 200-fold magnification of the morphology, (b) is a 2000-fold magnification of the morphology, (c) is a 5000-fold magnification of the morphology, and (d) is a 10000-fold magnification of the morphology. DETAILED DESCRIPTION

[0038] The following detailed description of the present invention will make the features and advantages of the present invention more clear and explicit.

[0039] The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise noted.

[0040] The present invention provides a high-temperature, high-radiation coating which can be prepared on a large area by air spraying, can be cured at room temperature, and can be directly applied at high temperature. The coating adopts high-temperature, high-radiation fillers such as tantalum silicide modified by praseodymium oxide, wherein tantalum silicide is a core high-radiation filler for achieving high-temperature, high-radiation rate of 1650°C. The high-temperature oxidation resistance of tantalum silicide is significantly improved by praseodymium oxide coating modification, so that the high-temperature emissivity of tantalum silicide is more stable and the service life is longer. At the same time, the coating has the advantages of simple large-area preparation process, room-temperature curing, high-temperature direct application, and easy repair, and can meet the high-temperature radiation heat dissipation needs in military and civilian fields.

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

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

[0043] In a specific embodiment, the praseodymium oxide modified tantalum silicide is prepared by uniformly mixing an aqueous solution of one of praseodymium sulfate, praseodymium nitrate or praseodymium chloride with tantalum silicide, and then drying at 100-150°C for 4 hours, and finally heating and sintering at 1000°C for 6 hours. After sintering, praseodymium sulfate, praseodymium nitrate or praseodymium chloride forms praseodymium oxide coated on the surface of tantalum silicide. On the one hand, the praseodymium oxide coating layer can block the tantalum silicide from contacting oxygen and reducing its oxidation. On the other hand, praseodymium oxide can react with the silicon oxide formed by the siloxazane resin around it at high temperature and a small amount of silicon oxide generated by the oxidation of tantalum silicide at high temperature to form a rare earth silicate with a dense structure, which further prevents the oxidation of tantalum silicide, significantly improves the high temperature oxidation resistance of tantalum silicide, and makes the high temperature emissivity of tantalum silicide more stable and has a longer service life.

[0044] In a 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 a specific embodiment, the mass percentage of each component in the nano-SiC whisker reinforced polysiloxazane is as follows: the nano-SiC whiskers are β-nano-SiC whiskers, accounting for 5% to 15% of the total mass of the nano-SiC whisker reinforced polysiloxazane, and the optimal range is 8% to 12%.

[0046] The thickness of the high radiation coating prepared by the present invention is 50-150 μm, and the optimal range is 60-120 μm.

[0047] like Figure 1 The figure shows a flow chart of preparing a room temperature curing high temperature and high radiation coating according to the present invention. The preparation method of the room temperature curing high temperature and high radiation coating according to the present invention specifically comprises the following steps:

[0048] First, nano silicon carbide whiskers and polysiloxazane resin are mixed and dispersed at high speed for 1 to 3 hours, and 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 to 6 hours, and the evenly mixed coating is sprayed on the surface of the substrate to be sprayed, and then cured at room temperature for 48 to 72 hours; the organic solvent is a mixture of butyl acetate and ethyl acetate.

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

[0050] In a specific embodiment, the mass percentage content of butyl acetate in the mixed solvent is 60% to 100%, wherein when the spraying environment temperature is lower than 15°C, the mass percentage content of butyl acetate in the mixed solvent is 60% to 80%, and when the spraying environment temperature is higher than 15°C, the mass percentage content of butyl acetate in the mixed solvent is 80% to 100%.

[0051] Example 1

[0052] First, nano-silicon carbide whiskers with a nano-silicon carbide whisker content of 12% were mixed with polysiloxazane resin and dispersed and mixed at high speed for 2 hours to prepare reinforced polysiloxazane, and then high-temperature and high-radiation coatings were prepared, and the raw material ratio was (mass percentage content):

[0053] The coating contains 40wt% of organic solvent and 60wt% of coating raw material;

[0054] The organic solvent is 70wt% butyl acetate and 30wt% ethyl acetate;

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

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

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

[0058] Finally, the high-radiation coating prepared by spraying was placed at room temperature for 60 hours, and the obtained coating thickness was 110 μm.

[0059] The preparation method of praseodymium oxide modified tantalum silicide comprises:

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

[0061] The high temperature resistant and high radiation coating has an emissivity of 0.88 at 600℃ and 0.90 at 1000℃, and a maximum operating temperature of 1650℃. Figure 2 and Figure 3 shown.

[0062] Example 2

[0063] First, nano silicon carbide whiskers with a nano silicon carbide whisker content of 5% were mixed with polysiloxazane resin, and dispersed and mixed at high speed for 2 hours to prepare reinforced polysiloxazane, and then high-temperature and high-radiation coatings were prepared, and the raw material ratio was (mass percentage content):

[0064] The coating contains 40wt% of organic solvent and 60wt% of coating raw material;

[0065] The organic solvent is butyl acetate;

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

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

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

[0069] Finally, the high-radiation coating prepared by spraying was placed at room temperature for 48 hours, and the obtained coating thickness was 60 μm.

[0070] The preparation method of praseodymium oxide modified tantalum silicide comprises:

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

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

[0073] Example 3

[0074] First, nano silicon carbide whiskers with a nano silicon carbide whisker content of 8% were mixed with polysiloxazane resin, and dispersed and mixed at high speed for 2 hours to prepare reinforced polysiloxazane, and then high-temperature and high-radiation coatings were prepared, and the raw material ratio was (mass percentage content):

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

[0076] The organic solvent is butyl acetate;

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

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

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

[0080] Finally, the high-radiation coating prepared by spraying was placed at room temperature for 48 hours, and the obtained coating thickness was 150 μm.

[0081] The preparation method of praseodymium oxide modified tantalum silicide comprises:

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

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

[0084] Example 4

[0085] First, nano-silicon carbide whiskers with a nano-silicon carbide whisker content of 15% were mixed with polysiloxazane resin and dispersed and mixed at high speed for 2 hours to prepare reinforced polysiloxazane, and then high-temperature and high-radiation coatings were prepared, and the raw material ratio was (mass percentage content):

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

[0087] The organic solvent is 60wt% butyl acetate and 40wt% ethyl acetate;

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

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

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

[0091] Finally, the high-radiation coating prepared by spraying was placed at room temperature for 72 hours, and the obtained coating thickness was 100 μm.

[0092] The preparation method of praseodymium oxide modified tantalum silicide comprises:

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

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

[0095] Example 5

[0096] First, nano-silicon carbide whiskers with a nano-silicon carbide whisker content of 12% were mixed with polysiloxazane resin and dispersed and mixed at high speed for 1 hour to prepare reinforced polysiloxazane, and then high-temperature and high-radiation coatings were prepared, and the raw material ratio was (mass percentage content):

[0097] The coating contains 45wt% of organic solvent and 55wt% of coating raw material;

[0098] The organic solvent is 90wt% butyl acetate and 10wt% ethyl acetate;

[0099] The coating material comprises 20wt% of reinforced polysiloxazane and 80wt% of solid filler; the solid filler comprises 60wt% of tantalum silicide modified with praseodymium oxide, 20wt% of molybdenum silicide and 20wt% of black silicon carbide;

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

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

[0102] Finally, the high-radiation coating prepared by spraying was placed at room temperature for 72 hours, and the obtained coating thickness was 80 μm.

[0103] The preparation method of praseodymium oxide modified tantalum silicide comprises:

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

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

[0106] Example 6

[0107] First, nano-silicon carbide whiskers with a nano-silicon carbide whisker content of 10% were mixed with polysiloxazane resin and dispersed and mixed at high speed for 3 hours to prepare reinforced polysiloxazane, and then high-temperature and high-radiation coatings were prepared, and the raw material ratio was (mass percentage content):

[0108] The coating contains 45wt% of organic solvent and 55wt% of coating raw material;

[0109] The organic solvent is 90wt% butyl acetate and 10wt% ethyl acetate;

[0110] The coating material comprises 20 wt% of reinforced polysiloxazane and 80 wt% of solid filler; the solid filler comprises 40 wt% of tantalum silicide modified with praseodymium oxide, 40 wt% of molybdenum silicide and 20 wt% of black silicon carbide;

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

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

[0113] Finally, the high-radiation coating prepared by spraying was placed at room temperature for 72 hours. The obtained coating thickness was 120 μm.

[0114] The preparation method of praseodymium oxide modified tantalum silicide comprises:

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

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

[0117] Comparative Example 1:

[0118] The other conditions are the same as those in Example 1, except that the praseodymium oxide-modified tantalum silicide in Example 1 is replaced with tantalum silicide, and the obtained coating has an emissivity of 0.84 at 600° C., an emissivity of 0.85 at 1000° C., and a maximum use temperature of 1650° C. From the comparison between Comparative Example 1 and Example 1, it can be seen that the use of praseodymium oxide-modified tantalum silicide in the present invention can effectively improve the emissivity of the coating.

[0119] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

[0120] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A room temperature curing high temperature and high radiation coating, characterized in that: It is formed by spraying a coating containing fillers and film-forming materials; Fillers include black silicon carbide, molybdenum silicide, and praseodymium oxide-modified tantalum silicide; The film-forming material is polysiloxazane reinforced with nano-silicon carbide whiskers; The mass percentage of the filler in the coating is 70% to 80%.

2. The room temperature curing high temperature and high radiation coating according to claim 1, characterized in that: The mass percentage of each component in the filler is: Black silicon carbide 20% to 40%; Molybdenum silicide 20% to 40%; Praseodymium oxide modified tantalum silicide 40% to 60%.

3. The room temperature curing high temperature and high radiation coating according to claim 1, characterized in that: The preparation method of praseodymium oxide modified tantalum silicide comprises: The aqueous solution of the praseodymium compound is uniformly mixed with tantalum silicide to obtain a mixture; the praseodymium compound comprises one of praseodymium sulfate, praseodymium nitrate or praseodymium chloride; The mixture is dried at 100-150°C for 3-5 hours, and then heated and sintered at 900-1200°C for 4-8 hours.

4. The room temperature curing high temperature and high radiation coating according to claim 3, characterized in that: The molar ratio of praseodymium in the praseodymium-containing compound to tantalum in tantalum silicide is 1:8-10; In the aqueous solution containing the praseodymium compound, the molar concentration of praseodymium is 0.08 to 0.12 mol / L.

5. The room temperature curing high temperature and high radiation coating according to claim 1, characterized in that: The purity of black silicon carbide is 90% to 98%.

6. The room temperature curing high temperature and high radiation coating according to claim 1, characterized in that: In the nano silicon carbide whisker reinforced polysiloxazane, the nano silicon carbide whisker is beta nano silicon carbide whisker, and the mass percentage of the nano silicon carbide whisker is 5% to 15%.

7. The room temperature curing high temperature and high radiation coating according to claim 1, characterized in that: The coating thickness is 50-150 μm; The curing temperature of the coating is room temperature, and the emissivity at 600-1000°C is ≥0.

87.

8. A method for preparing a room temperature curing high temperature and high radiation coating according to any one of claims 1 to 7, characterized in that: include: The film-forming material, the filler and the organic solvent are uniformly mixed to obtain the coating; The coating is sprayed on the surface of the substrate and cured at room temperature for 48 to 72 hours to obtain a room temperature cured high temperature and high radiation coating.

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

10. The method for preparing a room temperature curing high temperature and high radiation coating according to claim 9, characterized in that: When the spraying environment temperature is lower than 15°C, the mass percentage of butyl acetate in the organic solvent is 60% to 80%; When the spraying environment temperature is higher than 15° C., the mass percentage content of butyl acetate in the organic solvent is 80% to 100%.

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