Anti-ultraviolet and atomic oxygen irradiation intelligent thermal control coating with low solar absorptivity and preparation method of anti-ultraviolet and atomic oxygen irradiation intelligent thermal control coating

Abstract

The invention relates to an intelligent thermal control coating and a preparation method thereof, in particular to an anti-ultraviolet and atomic oxygen irradiation low-solar-absorptivity intelligent thermal control coating and a preparation method thereof. The problem that an existing thermal control coating material cannot achieve ultraviolet radiation protection and atomic oxygen radiation protection at the same time is solved. The intelligent thermal control coating is composed of a substrate, a reflecting layer, a dielectric layer, a VO2 functional layer, an oxygen-enriched protective layer and a solar reflecting layer / ultraviolet shielding layer from bottom to top in sequence. The preparation method comprises the following steps: 1, substrate pretreatment; 2, preparing a reflecting layer; 3, preparing a dielectric layer; 4, preparing a VO2 functional layer; 5, preparing an oxygen-enriched protective layer; and 6, preparing a solar reflecting layer / ultraviolet shielding layer. The invention is used for the anti-ultraviolet and atomic oxygen irradiation low-solar-absorptivity intelligent thermal control coating and the preparation thereof.

Description

Technical Field

[0001] The invention relates to an intelligent thermal control coating and a preparation method thereof. Background Art

[0002] When a spacecraft is operating in space, its surface temperatures can fluctuate by hundreds of degrees Celsius due to fluctuating solar radiation. Maintaining all aboard equipment and payloads within a relatively stable temperature range ensures the proper functioning of the spacecraft in the harsh space environment. Thermal control materials play a crucial role in the spacecraft's thermal control system, crucially determining its lifespan, reliability, and overall operational performance. The increasing complexity of maneuvering missions has created new demands for the development of thermal control materials for spacecraft. As a representative thermochromic material, VO2 has attracted widespread attention and is increasingly being applied in the field of intelligent thermal control due to its significant changes in infrared optical properties before and after the metal-insulator phase transition. Thermal control coatings covering the exterior of spacecraft are often exposed to the harsh environment of space, especially for spacecraft operating in low-Earth orbit or conducting deep space exploration missions. In low-Earth orbit, due to the constant exposure to solar radiation and atomic oxygen, thermal control coating materials are susceptible to damage from ultraviolet radiation and atomic oxygen. Due to the long operational lifespan of deep space exploration spacecraft, prolonged exposure to solar radiation, especially high-energy ultraviolet radiation, can severely impact the performance and lifespan of intelligent thermal control materials on the spacecraft's surface. Atomic oxygen erosion and oxidation of the material surface can alter the thermal control material's surface state, chemical composition, and crystal structure. Ultraviolet radiation can induce a photoelectric effect, often leading to changes in the material's chemical composition and crystal structure, which in turn affects the thermal radiation characteristics and stability of the thermal control material. Furthermore, the combined effects of ultraviolet radiation and atomic oxygen radiation can accelerate the attenuation of thermal radiation characteristics such as infrared emissivity and solar absorptivity of intelligent thermal control materials. Therefore, when used in spacecraft, these thermal control coatings require protection from ultraviolet radiation and atomic oxygen. Summary of the Invention

[0003] The present invention aims to solve the problem that existing thermal control coating materials cannot simultaneously achieve protection against ultraviolet radiation and atomic oxygen radiation, and further provide an intelligent thermal control coating with low solar absorption ratio that is resistant to ultraviolet radiation and atomic oxygen radiation, and a preparation method thereof.

[0004] An intelligent thermal control coating with low solar absorption ratio and resistance to ultraviolet and atomic oxygen radiation consists of a substrate, a reflective layer, a dielectric layer, a VO2 functional layer, an oxygen-rich protective layer and a solar reflective layer / ultraviolet shielding layer from bottom to top.

[0005] A method for preparing an intelligent thermal control coating with low solar absorption ratio and resistance to ultraviolet and atomic oxygen radiation is carried out according to the following steps:

[0006] 1. Substrate pretreatment:

[0007] Polishing, multiple cleaning and drying of the substrate to obtain a pretreated substrate;

[0008] 2. Preparation of reflective layer:

[0009] A reflective layer is prepared on one surface of the pretreated substrate by using magnetron sputtering, electron beam evaporation, pulsed laser deposition or atomic layer deposition;

[0010] 3. Preparation of dielectric layer:

[0011] A dielectric layer is prepared on the surface of the reflective layer by using magnetron sputtering, electron beam evaporation, pulsed laser deposition or atomic layer deposition;

[0012] 4. Preparation of VO2 functional layer:

[0013] A thin film is prepared on the surface of the dielectric layer by magnetron sputtering, electron beam evaporation, pulsed laser deposition or atomic layer deposition, and then post-processed to obtain a VO2 functional layer;

[0014] 5. Preparation of oxygen-rich protective layer:

[0015] An oxygen-rich protective layer is prepared on the surface of the VO2 functional layer by using magnetron sputtering, electron beam evaporation, pulsed laser deposition or atomic layer deposition methods;

[0016] 6. Preparation of solar reflection layer / UV shielding layer:

[0017] A solar reflection layer / UV shielding layer is prepared on the surface of the oxygen-rich protective layer by using magnetron sputtering, electron beam evaporation, pulsed laser deposition or atomic layer deposition methods, thereby obtaining an intelligent thermal control coating that is resistant to UV and atomic oxygen radiation and has a low solar absorption ratio.

[0018] The beneficial effects of the present invention are:

[0019] The present invention is mainly based on the demand for light weight, energy saving and high space stability of spacecraft thermal control coatings, and provides an intelligent thermal control coating with low solar absorption ratio that is resistant to ultraviolet and atomic oxygen radiation and a preparation method thereof; the prepared thermal control coating can realize adaptive adjustment of infrared band emissivity, maintain low infrared emissivity at low temperature, and convert to high emissivity at high temperature, with large infrared emissivity modulation amplitude and low solar absorption ratio; the prepared protective layer has excellent anti-proto-oxygen, anti-ultraviolet radiation and thermal protection performance, and the intelligent thermal control coating has good thermal stability and cyclic stability; at the same time, the coating is light, does not require external energy drive, has the characteristics of low preparation cost, and supports large-scale production, and is particularly suitable for intelligent thermal management of spacecraft to cope with complex thermal environments and harsh space environments. The preparation process of the present invention has the characteristics of diversity, simplicity of method, low cost, high repeatability and large-scale preparation.

[0020] (1) By introducing an oxygen-rich protective layer and a solar reflective layer with UV shielding effect, the VO2 functional layer can be prevented from losing oxygen and generating oxygen vacancies under UV radiation. At the same time, the intensity of UV radiation on the VO2 functional layer and the underlying film layer is weakened, and the impact of UV radiation on the VO2 functional layer is reduced. It has excellent UV radiation protection performance and can effectively improve the stability of the intelligent thermal control coating under UV radiation.

[0021] (2) By introducing an oxygen-rich protective layer with a low atomic oxygen stripping rate, the thermal radiation performance attenuation caused by the mechanical damage and oxidation of atomic oxygen to the VO2 functional layer and the underlying dielectric layer and reflective layer is avoided. It has excellent atomic oxygen radiation protection performance and can effectively improve the stability of the intelligent thermal control coating under atomic oxygen irradiation.

[0022] (3) By leveraging the specific reflection characteristics of the solar reflective layer in the solar spectrum range and combining it with the phase matching caused by the refractive index difference between the solar reflective layer and the oxygen-rich protective layer, the light absorption of the intelligent thermal control coating in the solar band of 200nm to 2500nm can be significantly suppressed, thereby obtaining a lower solar absorption rate.

[0023] (4) The asymmetric FP resonant cavity structure, consisting of a reflective layer, a dielectric layer, and a VO2 functional layer, can significantly enhance the infrared emissivity control capability of the intelligent thermal control coating. By adjusting the thickness of the dielectric layer and the VO2 functional layer, the infrared emissivity of the coating in both the low-temperature insulation state and the high-temperature heat dissipation state can be precisely controlled to meet the differentiated thermal management requirements of spacecraft. Compared with traditional intelligent thermal control coatings and active control schemes with a single emissivity, this structure effectively suppresses the direct interference of heat flow from outside space on the spacecraft without consuming additional energy.

[0024] (5) By regulating the phase change characteristics of VO2 thin films with element doping, the operating temperature range of the intelligent thermal control coating can be adjusted to make it suitable for the application scenarios of various spacecraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic structural diagram of the intelligent thermal control coating with low solar absorption ratio and resistance to ultraviolet radiation and atomic oxygen radiation of the present invention, wherein 1 is the substrate, 2 is the reflective layer, 3 is the dielectric layer, 4 is the VO2 functional layer, 5 is the oxygen-rich barrier layer, and 6 is the solar reflective layer / ultraviolet shielding layer. DETAILED DESCRIPTION

[0026] Specific implementation method 1, combined with Figure 1 Specific description: This embodiment is an intelligent thermal control coating with low solar absorption ratio and resistance to ultraviolet and atomic oxygen radiation, which is composed of a substrate, a reflective layer, a dielectric layer, a VO2 functional layer, an oxygen-rich protective layer and a solar reflective layer / ultraviolet shielding layer from bottom to top.

[0027] The substrate in this embodiment plays a supporting role for the composite membrane structure and can also be replaced with any high-temperature resistant and heat-conductive substrate with a smooth and flat surface;

[0028] The reflective layer in this embodiment is made of a material with a reflectivity of more than 80% in the infrared band;

[0029] The dielectric layer of this specific embodiment is a lossless dielectric layer material with a relatively small refractive index in the infrared band of 2.5 μm to 25 μm;

[0030] In this specific embodiment, when the temperature of the VO2 functional layer is lower than the phase transition temperature, the thermal control coating exhibits low infrared emissivity, and when the temperature is higher than the phase transition temperature, the thermal control coating exhibits high infrared emissivity;

[0031] In this specific embodiment, the oxygen-rich protective layer is a saturated oxide with a low atomic oxygen stripping rate. Due to its low oxygen vacancy generation energy, it can serve as an ultraviolet protection layer to prevent the VO2 functional layer from losing oxygen under vacuum ultraviolet irradiation, resulting in the attenuation of the adaptive control performance of the intelligent thermal control coating. It also serves as an atomic oxygen protection layer to prevent the intelligent thermal control coating from failing under high-flux atomic oxygen irradiation.

[0032] In this specific embodiment, the solar reflection layer / UV shielding layer is made of a material with a reflectivity of more than 20% in the solar band and a transmittance of more than 55% in the mid- and far-infrared bands. It reflects part of the incident solar radiation, reduces the solar absorption ratio of the intelligent thermal control coating, and also serves as a UV shielding layer to block ultraviolet rays from directly acting on the VO2 functional layer, preventing the VO2 functional layer from attenuating and failing under ultraviolet radiation.

[0033] The beneficial effects of this embodiment are:

[0034] This embodiment is mainly based on the demand for light weight, energy saving and high space stability of spacecraft thermal control coatings, and provides an intelligent thermal control coating with low solar absorption ratio that is resistant to ultraviolet and atomic oxygen radiation and its preparation method; the prepared thermal control coating can realize adaptive adjustment of infrared band emissivity, maintain low infrared emissivity at low temperature, and convert to high emissivity at high temperature, with large infrared emissivity modulation amplitude and low solar absorption ratio; the prepared protective layer has excellent anti-proto-oxygen, anti-ultraviolet radiation and thermal protection properties, and the intelligent thermal control coating has good thermal stability and cyclic stability; at the same time, the coating is light, does not require external energy drive, has low preparation cost, supports large-scale production, etc., and is particularly suitable for intelligent thermal management of spacecraft to cope with complex thermal environments and harsh space environments. The preparation process of this embodiment is diverse and has the characteristics of simple method, low cost, high repeatability and large-scale preparation.

[0035] (1) By introducing an oxygen-rich protective layer and a solar reflective layer with UV shielding effect, the VO2 functional layer can be prevented from losing oxygen and generating oxygen vacancies under UV radiation. At the same time, the intensity of UV radiation on the VO2 functional layer and the underlying film layer is weakened, and the impact of UV radiation on the VO2 functional layer is reduced. It has excellent UV radiation protection performance and can effectively improve the stability of the intelligent thermal control coating under UV radiation.

[0036] (2) By introducing an oxygen-rich protective layer with a low atomic oxygen stripping rate, the thermal radiation performance attenuation caused by the mechanical damage and oxidation of atomic oxygen to the VO2 functional layer and the underlying dielectric layer and reflective layer is avoided. It has excellent atomic oxygen radiation protection performance and can effectively improve the stability of the intelligent thermal control coating under atomic oxygen irradiation.

[0037] (3) By leveraging the specific reflection characteristics of the solar reflective layer in the solar spectrum range and combining it with the phase matching caused by the refractive index difference between the solar reflective layer and the oxygen-rich protective layer, the light absorption of the intelligent thermal control coating in the solar band of 200nm to 2500nm can be significantly suppressed, thereby obtaining a lower solar absorption rate.

[0038] (4) The asymmetric FP resonant cavity structure, consisting of a reflective layer, a dielectric layer, and a VO2 functional layer, can significantly enhance the infrared emissivity control capability of the intelligent thermal control coating. By adjusting the thickness of the dielectric layer and the VO2 functional layer, the infrared emissivity of the coating in both the low-temperature insulation state and the high-temperature heat dissipation state can be precisely controlled to meet the differentiated thermal management requirements of spacecraft. Compared with traditional intelligent thermal control coatings and active control schemes with a single emissivity, this structure effectively suppresses the direct interference of heat flow from outside space on the spacecraft without consuming additional energy.

[0039] (5) By regulating the phase change characteristics of VO2 thin films with element doping, the operating temperature range of the intelligent thermal control coating can be adjusted to make it suitable for the application scenarios of various spacecraft.

[0040] Specific embodiment 2: This embodiment differs from specific embodiment 1 in that the substrate is made of quartz glass, soda-lime glass, sapphire substrate, metal aluminum sheet, silicon wafer or zirconia ceramic, and has a thickness of 0.1 mm to 1 mm. Other aspects are the same as specific embodiment 1.

[0041] Specific embodiment 3: This embodiment differs from specific embodiment 1 or 2 in that the reflective layer is made of Al, Au, Ag, Cu, W, Rh, TiN, ITO, or AZO, and has a thickness of 150 nm to 250 nm. Other aspects are the same as specific embodiment 1 or 2.

[0042] Specific embodiment 4: This embodiment differs from specific embodiments 1 to 3 in that the dielectric layer is made of HfO2, CaF2, SiO2, ZnO, TiO2, MgF2, Al2O3, or ZrO2, and has a thickness of 500nm to 1000nm. Other aspects are the same as specific embodiments 1 to 3.

[0043] Specific embodiment 5: This embodiment differs from specific embodiments 1 to 4 in that the VO2 functional layer is VO2 or element-doped VO2 with a thickness of 30nm to 140nm. It is the same as specific embodiments 1 to 4.

[0044] The element-doped VO2 described in this specific embodiment is W-doped VO2, Mo-doped VO2, Eu-doped VO2, F-doped VO2, W-Mg co-doped VO2, W-Mo co-doped VO2 or F-Mo co-doped VO2.

[0045] Specific embodiment 6: This embodiment differs from specific embodiments 1 to 5 in that the oxygen-rich protective layer is made of Al2O3, ZnO, TiO2 or ZrO2, and has a thickness of 50nm to 600nm. Other aspects are the same as specific embodiments 1 to 5.

[0046] Specific embodiment 7: This embodiment differs from specific embodiments 1 to 6 in that the solar reflection layer / ultraviolet shielding layer is made of Si, Ge, ZnSe, ZnS, GaAs, GaP, or diamond, and has a thickness of 30 nm to 500 nm. Other aspects are the same as specific embodiments 1 to 6.

[0047] Specific embodiment eight: A method for preparing an intelligent thermal control coating with low solar absorption ratio and resistance to ultraviolet and atomic oxygen radiation, which is carried out according to the following steps:

[0048] 1. Substrate pretreatment:

[0049] Polishing, multiple cleaning and drying of the substrate to obtain a pretreated substrate;

[0050] 2. Preparation of reflective layer:

[0051] A reflective layer is prepared on one surface of the pretreated substrate by using magnetron sputtering, electron beam evaporation, pulsed laser deposition or atomic layer deposition;

[0052] 3. Preparation of dielectric layer:

[0053] A dielectric layer is prepared on the surface of the reflective layer by using magnetron sputtering, electron beam evaporation, pulsed laser deposition or atomic layer deposition;

[0054] 4. Preparation of VO2 functional layer:

[0055] A thin film is prepared on the surface of the dielectric layer by magnetron sputtering, electron beam evaporation, pulsed laser deposition or atomic layer deposition, and then post-processed to obtain a VO2 functional layer;

[0056] 5. Preparation of oxygen-rich protective layer:

[0057] An oxygen-rich protective layer is prepared on the surface of the VO2 functional layer by using magnetron sputtering, electron beam evaporation, pulsed laser deposition or atomic layer deposition methods;

[0058] 6. Preparation of solar reflection layer / UV shielding layer:

[0059] A solar reflection layer / UV shielding layer is prepared on the surface of the oxygen-rich protective layer by using magnetron sputtering, electron beam evaporation, pulsed laser deposition or atomic layer deposition methods, thereby obtaining an intelligent thermal control coating that is resistant to UV and atomic oxygen radiation and has a low solar absorption ratio.

[0060] Specific embodiment 9: This embodiment differs from specific embodiment 8 in that: in step 2, when the reflective layer is Al, the following steps are specifically performed: in a vacuum degree lower than 1.0×10 -3 A reflective layer is prepared on one surface of the pretreated substrate by magnetron sputtering technology under the conditions of 0.4 Pa to 1.5 Pa, a DC power of 100 W to 250 W, a pressure of 0.4 Pa to 1.5 Pa, an argon flow rate of 60 sccm to 100 sccm, and a substrate temperature of room temperature to 200° C.;

[0061] In step 3, when the dielectric layer is HfO2, the following steps are specifically performed: using a metal Hf target as a target material, in a vacuum degree lower than 1.8×10 -3 A dielectric layer is prepared on the surface of the reflective layer by using magnetron sputtering technology under the conditions of 0.4 Pa ~ 1.5 Pa, working gas pressure of 0.4 Pa ~ 1.5 Pa, argon flow rate of 60 sccm ~ 100 sccm, oxygen flow rate of 1 sccm ~ 10 sccm, substrate temperature of room temperature to 400 ° C and DC power of 100 W ~ 300 W;

[0062] In step 4, the vacuum degree is lower than 1.5×10 -3A thin film is deposited on the surface of the dielectric layer using magnetron sputtering technology under the following conditions: a flow rate of 100 sccm to 160 sccm, a frequency of 300 Hz to 450 Hz, a pulse width of 45 μs to 50 μs, a power of 180 W to 250 W, a high-power pulse voltage of 450 V to 650 V, a pressure of 0.4 Pa to 1.2 Pa, an argon flow rate of 70 sccm to 95 sccm, an oxygen flow rate of 0.8 sccm to 2.4 sccm, and a substrate temperature of 200° C. to 550° C. The film is then heated to 300° C. to 600° C. at an argon flow rate of 60 sccm to 160 sccm and a heating rate of 1° C. / min to 5° C. / min, and maintained at 300° C. to 600° C. for 1 to 7 hours at an argon flow rate of 60 sccm to 160 sccm, followed by natural cooling to room temperature to obtain a VO2 functional layer. Other steps are the same as those in the eighth embodiment.

[0063] Specific embodiment 10: The difference between this embodiment and either of the specific embodiments 8 or 9 is that in step 5, when the oxygen-rich protective layer is Al2O3, the following steps are specifically performed: when the vacuum degree is lower than 2.0×10 -3 Under the conditions of 100W~300W DC power, 0.4Pa~1.5Pa pressure, 50sccm~100sccm argon flow rate, 3sccm~10sccm oxygen flow rate and substrate temperature from room temperature to 400℃, an oxygen-rich protective layer was prepared on the surface of the VO2 functional layer by using magnetron sputtering technology;

[0064] In step 6, when the solar reflection layer / ultraviolet shielding layer is Si, the following steps are specifically performed: -3 A solar reflective layer / UV shielding layer is formed on the surface of the oxygen-rich protective layer using magnetron sputtering technology under the following conditions: a RF power of 100 W to 250 W, a pressure of 0.4 Pa to 1.2 Pa, an argon gas flow rate of 60 sccm to 100 sccm, and a substrate temperature of room temperature to 400°C. Other steps are the same as those in the eighth or ninth embodiment.

[0065] The following examples are used to verify the beneficial effects of the present invention:

[0066] Example 1:

[0067] An intelligent thermal control coating with low solar absorption ratio and resistance to ultraviolet and atomic oxygen radiation, which is composed of a substrate, a reflective layer, a dielectric layer, a VO2 functional layer, an oxygen-rich protective layer and a solar reflective layer / ultraviolet shielding layer from bottom to top;

[0068] The substrate is made of quartz glass and has a thickness of 0.2 mm.

[0069] The reflective layer is Al and has a thickness of 150 nm.

[0070] The dielectric layer is HfO2 and has a thickness of 800nm.

[0071] The VO2 functional layer is W-doped VO2, where W accounts for 2% of the total number of W and V atoms and has a thickness of 50 nm.

[0072] The oxygen-rich protective layer is Al2O3 and has a thickness of 50nm.

[0073] The solar reflection layer / ultraviolet shielding layer is made of Si and has a thickness of 50 nm.

[0074] A method for preparing an intelligent thermal control coating with low solar absorption ratio and resistance to ultraviolet and atomic oxygen radiation is carried out according to the following steps:

[0075] 1. Substrate pretreatment:

[0076] The substrate was polished, then ultrasonically cleaned multiple times using anhydrous ethanol and deionized water in sequence, and finally dried in a forced air drying oven at 80°C for 8 hours to obtain a pretreated substrate;

[0077] 2. Preparation of reflective layer:

[0078] At a vacuum degree of 6.5×10 -4 Under the conditions of 0.5 Pa, DC power of 150 W, pressure of 0.5 Pa, argon flow rate of 100 sccm and substrate temperature of 200°C, a reflective layer was prepared on one surface of the pretreated substrate by using magnetron sputtering technology;

[0079] 3. Preparation of dielectric layer:

[0080] Using metal Hf target as target material, the vacuum degree is 9.0×10 -4 Under the conditions of 0.9 Pa, working gas pressure of 0.9 Pa, argon flow rate of 85 sccm, oxygen flow rate of 6 sccm, substrate temperature of 200°C and DC power of 200 W, a dielectric layer was prepared on the surface of the reflective layer by using magnetron sputtering technology;

[0081] 4. Preparation of VO2 functional layer:

[0082] At a vacuum degree of 5×10 -4Pa, frequency of 450Hz, pulse width of 50μs, power of 200W, high-power pulse voltage of 580V, pressure of 0.85Pa, argon flow rate of 75sccm, oxygen flow rate of 0.8sccm and substrate temperature of 400℃, a thin film was prepared on the surface of the dielectric layer by using magnetron sputtering technology, and then placed in a tube furnace, and heated to 400℃ under the conditions of argon flow rate of 120sccm and heating rate of 1℃ / min, and kept warm for 4h under the conditions of argon flow rate of 120sccm and temperature of 400℃, and finally naturally cooled to room temperature to obtain a VO2 functional layer;

[0083] 5. Preparation of oxygen-rich protective layer:

[0084] At a vacuum degree of 8.0×10 -4 Under the conditions of 1.5 Pa, 150 W DC power, 0.5 Pa pressure, 55 sccm argon flow rate, 5.5 sccm oxygen flow rate and substrate temperature ranging from room temperature to 400 ° C, an oxygen-rich protective layer was prepared on the surface of the VO2 functional layer by using magnetron sputtering technology;

[0085] 6. Preparation of solar reflection layer / UV shielding layer:

[0086] At a vacuum degree of 1.4×10 -3 Under the conditions of 1.54 Pa, RF power of 200 W, pressure of 0.65 Pa, argon flow rate of 90 sccm and substrate temperature of 200 ° C, the solar reflection layer / UV shielding layer was prepared on the surface of the oxygen-rich protective layer by using magnetron sputtering technology, that is, an intelligent thermal control coating with anti-ultraviolet and atomic oxygen radiation and low solar absorption ratio was obtained.

[0087] Example 2: This example differs from Example 1 in that the thickness of the oxygen-rich protective layer is 100 nm. Other aspects are the same as Example 1.

[0088] Example 3: This example differs from Example 1 in that the thickness of the oxygen-rich protective layer is 200 nm. Other aspects are the same as Example 1.

[0089] Example 4: This example differs from Example 1 in that the thickness of the oxygen-rich protective layer is 300 nm. Other aspects are the same as Example 1.

[0090] Example 5: This example differs from Example 1 in that the thickness of the oxygen-rich protective layer is 400 nm. Other aspects are the same as Example 1.

[0091] Example 6: This example differs from Example 1 in that the thickness of the oxygen-rich protective layer is 500 nm. Other aspects are the same as Example 1.

[0092] Example 7: This example differs from Example 1 in that the thickness of the solar reflection layer / ultraviolet shielding layer is 100 nm. Other aspects are the same as Example 1.

[0093] Example 8: This example differs from Example 1 in that the thickness of the solar reflection layer / ultraviolet shielding layer is 150 nm. Other aspects are the same as Example 1.

[0094] Example 9: This example differs from Example 1 in that the thickness of the solar reflection layer / ultraviolet shielding layer is 200 nm. Other aspects are the same as Example 1.

[0095] Example 10: This example differs from Example 1 in that the thickness of the solar reflection layer / ultraviolet shielding layer is 250 nm. Other aspects are the same as Example 1.

[0096] Comparative Experiment 1: This comparative experiment differs from Example 1 in that the oxygen-enriched protective layer is omitted. Other aspects are the same as Example 1.

[0097] Comparative Experiment 2: This comparative experiment differs from Example 1 in that the solar reflection layer / ultraviolet shielding layer is omitted. Other aspects are the same as Example 1.

[0098] Comparative Experiment 3: This comparative experiment differs from Example 1 in that the oxygen-enriched protective layer and the solar reflection layer / ultraviolet shielding layer are omitted. Other aspects are the same as Example 1.

[0099] Infrared emissivity test: Use a Fourier transform infrared spectrometer to perform in-situ temperature-variable hemispherical infrared emissivity test on the prepared samples to obtain the corresponding emissivity of the samples under low and high temperature conditions;

[0100] Solar absorption ratio test: Use a UV-visible-near-infrared spectrophotometer to conduct an in-situ temperature-varying solar absorption ratio test on the prepared samples to obtain the corresponding solar absorption ratios of the samples under low and high temperature conditions.

[0101] The UV and atomic oxygen irradiation resistant low solar absorption ratio intelligent thermal control coating prepared in Example 1 was tested for temperature-dependent reflectance spectroscopy in the wavelength range of 2.5μm to 25μm and 200nm to 2500nm. Calculations showed that the infrared emissivity of the sample at 0°C before irradiation was 0.23 and the solar absorption ratio was 0.35. The infrared emissivity of the sample at 70°C was 0.65 and the solar absorption ratio was 0.41. -3 Pa vacuum conditions, after the cumulative dose of 2000ESH (equivalent solar hours) of ultraviolet radiation test, the high and low temperature solar absorption ratio changes are less than 0.01, the low temperature hemisphere emissivity change value is 0.02, and the high temperature hemisphere emissivity change value is 0.02. The sample has been subjected to a cumulative flux of 6.2×10 16 atoms / cm 2After atomic oxygen irradiation, the mass loss was 0.05%, the change in high and low temperature solar absorption ratio was less than 0.01, the change in low temperature hemisphere emissivity was 0.03, and the change in high temperature hemisphere emissivity was 0.04. At the same time, the substrate was intact and showed no signs of corrosion. -3 Under vacuum conditions of 100 Pa, after exposure to a thermal vacuum environment at a test temperature of 400°C for 10 hours, the high and low temperature solar absorptivity and hemispherical emissivity remained unchanged. After 300 cycles of thermal cycling tests between -196°C and 120°C, the sample film showed no peeling or cracking, and the high and low temperature solar absorptivity and hemispherical emissivity remained unchanged.

[0102] The UV and atomic oxygen irradiation-resistant low solar absorption ratio intelligent thermal control coating prepared in Example 2 was tested for temperature-dependent reflectance spectroscopy in the wavelength range of 2.5μm to 25μm and 200nm to 2500nm. Calculations showed that the infrared emissivity of the sample at 0°C before irradiation was 0.26 and the solar absorption ratio was 0.34. The infrared emissivity of the sample at 70°C was 0.68 and the solar absorption ratio was 0.40. -3 Pa vacuum conditions, after the cumulative dose of 2000ESH (equivalent solar hours) of ultraviolet radiation test, the high and low temperature solar absorption ratio change value is less than 0.01, the high and low temperature hemispheric emissivity does not change. 16 atoms / cm 2 After atomic oxygen irradiation, the mass loss was 0.05%, the change in high and low temperature solar absorption ratio was less than 0.01, the change in low temperature hemisphere emissivity was 0.02, and the change in high temperature hemisphere emissivity was 0.03. At the same time, the substrate was intact and showed no signs of corrosion.

[0103] The UV and atomic oxygen irradiation-resistant low solar absorption ratio intelligent thermal control coating prepared in Example 3 was tested for temperature-dependent reflectance spectroscopy in the wavelength range of 2.5μm to 25μm and 200nm to 2500nm. Calculations showed that the infrared emissivity of the sample at 0°C before irradiation was 0.31 and the solar absorption ratio was 0.36. The infrared emissivity of the sample at 70°C was 0.68 and the solar absorption ratio was 0.41. The vacuum degree was better than 1.3×10 -3 Pa vacuum conditions, after the cumulative dose of 2000ESH (equivalent solar hours) of ultraviolet radiation test, the high and low temperature solar absorption ratio changes are less than 0.01, the low temperature hemisphere emissivity change is 0.02, and the high temperature hemisphere emissivity does not change. The sample has been subjected to a cumulative flux of 6.2×10 16 atoms / cm 2 After atomic oxygen irradiation, the mass loss was 0.05%, the change in high and low temperature solar absorption ratio was less than 0.01, the change in low temperature hemisphere emissivity was 0.02, and the change in high temperature hemisphere emissivity was 0.02. At the same time, the substrate was intact and showed no signs of corrosion.

[0104] The UV and atomic oxygen irradiation-resistant low solar absorption ratio intelligent thermal control coating prepared in Example 4 was tested for temperature-dependent reflectance spectroscopy in the wavelength range of 2.5μm to 25μm and 200nm to 2500nm. Calculations showed that the infrared emissivity of the sample at 0°C before irradiation was 0.32 and the solar absorption ratio was 0.37. The infrared emissivity of the sample at 70°C was 0.68 and the solar absorption ratio was 0.43. -3 Pa vacuum conditions, after the cumulative dose of 2000ESH (equivalent solar hours) of ultraviolet radiation test, the high and low temperature solar absorption ratio change value is less than 0.01, the high and low temperature hemispheric emissivity does not change. 16 atoms / cm 2 After atomic oxygen irradiation, the mass loss was 0.04%, the change in high and low temperature solar absorption ratio was less than 0.01, the high and low temperature hemispherical emissivity did not change, and the substrate was intact with no signs of corrosion.

[0105] The UV and atomic oxygen irradiation-resistant low solar absorption ratio intelligent thermal control coating prepared in Example 5 was tested for temperature-dependent reflectance spectroscopy in the wavelength range of 2.5μm to 25μm and 200nm to 2500nm. Calculations showed that the infrared emissivity of the sample at 0°C before irradiation was 0.32 and the solar absorption ratio was 0.38. The infrared emissivity of the sample at 70°C was 0.67 and the solar absorption ratio was 0.44. -3 Pa vacuum conditions, after the cumulative dose of 2000ESH (equivalent solar hours) of ultraviolet radiation test, the high and low temperature solar absorption ratio change value is less than 0.01, the high and low temperature hemispheric emissivity does not change. 16 atoms / cm 2 After atomic oxygen irradiation, the mass loss was 0.02%, the change in high and low temperature solar absorption ratio was less than 0.01, the high and low temperature hemispherical emissivity did not change, and the substrate was intact with no signs of corrosion.

[0106] The UV and atomic oxygen irradiation resistant low solar absorption ratio intelligent thermal control coating prepared in Example 6 was tested for temperature-dependent reflectance spectroscopy in the wavelength range of 2.5μm to 25μm and 200nm to 2500nm. The calculated results show that the infrared emissivity of the sample at 0°C before irradiation is 0.32 and the solar absorption ratio is 0.39. The infrared emissivity of the sample at 70°C is 0.67 and the solar absorption ratio is 0.44. -3 Pa vacuum conditions, after the cumulative dose of 2000ESH (equivalent solar hours) of ultraviolet radiation test, the high and low temperature solar absorption ratio change value is less than 0.01, the high and low temperature hemispheric emissivity does not change.16 atoms / cm 2 After atomic oxygen irradiation, the mass loss was 0.03%, the change in high and low temperature solar absorption ratio was less than 0.01, the high and low temperature hemispherical emissivity did not change, and the substrate was intact with no signs of corrosion.

[0107] The UV and atomic oxygen irradiation-resistant low solar absorption ratio intelligent thermal control coating prepared in Example 7 was tested for temperature-dependent reflectance spectroscopy in the wavelength range of 2.5μm to 25μm and 200nm to 2500nm. Calculations showed that the infrared emissivity of the sample at 0°C before irradiation was 0.24 and the solar absorption ratio was 0.37. The infrared emissivity of the sample at 70°C was 0.69 and the solar absorption ratio was 0.42. -3 Pa vacuum conditions, after the cumulative dose of 2000ESH (equivalent solar hours) of ultraviolet radiation test, the high and low temperature solar absorption ratio change value is less than 0.01, the high and low temperature hemispheric emissivity does not change. 16 atoms / cm 2 After atomic oxygen irradiation, the mass loss was 0.05%, the change in high and low temperature solar absorption ratio was less than 0.01, the high and low temperature hemispherical emissivity did not change, and the substrate was intact with no signs of corrosion.

[0108] The UV and atomic oxygen irradiation-resistant low solar absorption ratio intelligent thermal control coating prepared in Example 8 was tested for temperature-dependent reflectance spectroscopy in the wavelength range of 2.5μm to 25μm and 200nm to 2500nm. Calculations showed that the infrared emissivity of the sample at 0°C before irradiation was 0.26 and the solar absorption ratio was 0.39. The infrared emissivity of the sample at 70°C was 0.69 and the solar absorption ratio was 0.44. -3 Pa vacuum conditions, after the cumulative dose of 2000ESH (equivalent solar hours) of ultraviolet radiation test, the high and low temperature solar absorption ratio change value is less than 0.01, the high and low temperature hemispheric emissivity does not change. 16 atoms / cm 2 After atomic oxygen irradiation, the mass loss was 0.03%, the change in high and low temperature solar absorption ratio was less than 0.01, the high and low temperature hemispherical emissivity did not change, and the substrate was intact with no signs of corrosion.

[0109] The UV and atomic oxygen irradiation-resistant low solar absorption ratio intelligent thermal control coating prepared in Example 9 was tested for temperature-dependent reflectance spectroscopy in the wavelength range of 2.5μm to 25μm and 200nm to 2500nm. Calculations showed that the infrared emissivity of the sample at 0°C before irradiation was 0.27 and the solar absorption ratio was 0.39. The infrared emissivity of the sample at 70°C was 0.68 and the solar absorption ratio was 0.45.-3 Pa vacuum conditions, after the cumulative dose of 2000ESH (equivalent solar hours) of ultraviolet radiation test, the high and low temperature solar absorption ratio change value is less than 0.01, the high and low temperature hemispheric emissivity does not change. 16 atoms / cm 2 After atomic oxygen irradiation, the mass loss was 0.05%, the change in high and low temperature solar absorption ratio was less than 0.01, the high and low temperature hemispherical emissivity did not change, and the substrate was intact with no signs of corrosion.

[0110] The UV and atomic oxygen irradiation resistant low solar absorption ratio intelligent thermal control coating prepared in Example 10 was tested for temperature-dependent reflectance spectroscopy in the wavelength range of 2.5μm to 25μm and 200nm to 2500nm. Calculations showed that the infrared emissivity of the sample at 0°C before irradiation was 0.28 and the solar absorption ratio was 0.39. The infrared emissivity of the sample at 70°C was 0.67 and the solar absorption ratio was 0.45. -3 Pa vacuum conditions, after the cumulative dose of 2000ESH (equivalent solar hours) of ultraviolet radiation test, the high and low temperature solar absorption ratio change value is less than 0.01, the high and low temperature hemispheric emissivity does not change. 16 atoms / cm 2 After atomic oxygen irradiation, the mass loss was 0.04%, the change in high and low temperature solar absorption ratio was less than 0.01, the high and low temperature hemispherical emissivity did not change, and the substrate was intact with no signs of corrosion.

[0111] The UV and atomic oxygen irradiation-resistant low solar absorption ratio intelligent thermal control coating prepared in comparative experiment 1 was tested for temperature-dependent reflectance spectroscopy in the wavelength range of 2.5μm to 25μm and 200nm to 2500nm. Calculations showed that the infrared emissivity of the sample at 0℃ before irradiation was 0.19 and the solar absorption ratio was 0.37. The infrared emissivity of the sample at 70℃ was 0.68 and the solar absorption ratio was 0.48. -3 Pa vacuum conditions, after the cumulative dose of 2000ESH (equivalent solar hours) of ultraviolet irradiation test, the low-temperature solar absorptivity increased by 0.07, the high-temperature solar absorptivity increased by 0.05, the low-temperature hemispherical emissivity increased by 0.11, and the high-temperature hemispherical emissivity decreased by 0.06. The sample was subjected to a cumulative flux of 6.2×10 16 atoms / cm 2 After atomic oxygen irradiation, the mass loss was 0.12%, the low-temperature solar absorption ratio increased by 0.06, the high-temperature solar absorption ratio increased by 0.07, the low-temperature hemispherical emissivity increased by 0.10, and the high-temperature hemispherical emissivity remained unchanged. At the same time, the substrate was intact and showed no signs of erosion.

[0112] The UV and atomic oxygen irradiation-resistant low solar absorption ratio intelligent thermal control coating prepared in comparative experiment 2 was tested for temperature-dependent reflectance spectroscopy in the wavelength range of 2.5μm~25μm and 200nm~2500nm. The calculated results show that the infrared emissivity of the sample at 0℃ before irradiation is 0.22 and the solar absorption ratio is 0.49. The infrared emissivity of the sample at 70℃ is 0.66 and the solar absorption ratio is 0.65. -3 Pa vacuum conditions, after the cumulative dose of 2000ESH (equivalent solar hours) of ultraviolet radiation test, the high and low temperature solar absorption ratio change value is less than 0.01, the high and low temperature hemispheric emissivity does not change. 16 atoms / cm 2 After atomic oxygen irradiation, the mass loss was 0.02%, the change in high and low temperature solar absorption ratio was less than 0.01, the high and low temperature hemispherical emissivity did not change, and the substrate was intact with no signs of corrosion.

[0113] The UV and atomic oxygen irradiation-resistant low solar absorption ratio intelligent thermal control coating prepared in comparative experiment 3 was tested for temperature-dependent reflectance spectroscopy in the wavelength range of 2.5μm~25μm and 200nm~2500nm. The calculated results show that the infrared emissivity of the sample at 0℃ before irradiation is 0.19 and the solar absorption ratio is 0.50. The infrared emissivity of the sample at 70℃ is 0.67 and the solar absorption ratio is 0.67. -3 Pa vacuum conditions, after a cumulative dose of 2000ESH (equivalent solar hours) of ultraviolet irradiation test, the low-temperature solar absorptivity increased by 0.08, the high-temperature solar absorptivity increased by 0.06, the low-temperature hemispherical emissivity increased by 0.33, and the high-temperature hemispherical emissivity did not change. The high and low temperature infrared reflection curves overlapped, and the emissivity no longer had the adaptive control performance. The sample was subjected to a cumulative flux of 6.2×10 16 atoms / cm 2 After atomic oxygen irradiation, the mass loss was 0.27%, the low-temperature solar absorptivity increased by 0.07, the high-temperature solar absorptivity increased by 0.07, the low-temperature hemispherical emissivity increased by 0.03, the high-temperature hemispherical emissivity increased by 0.05, and irregular point-like erosion marks appeared on the surface of the substrate.

Claims

1. An intelligent thermal control coating with low solar absorption ratio and resistance to ultraviolet and atomic oxygen radiation, characterized in that It consists of a substrate, a reflective layer, a dielectric layer, a VO2 functional layer, an oxygen-rich protective layer and a solar reflective layer / ultraviolet shielding layer from bottom to top.

2. The ultraviolet and atomic oxygen radiation resistant low solar absorption ratio intelligent thermal control coating according to claim 1, characterized in that The substrate is quartz glass, soda-lime glass, sapphire substrate, metal aluminum sheet, silicon sheet or zirconia ceramic, and has a thickness of 0.1mm to 1mm.

3. The ultraviolet and atomic oxygen radiation resistant low solar absorption ratio intelligent thermal control coating according to claim 1, characterized in that The reflective layer is made of Al, Au, Ag, Cu, W, Rh, TiN, ITO or AZO, and has a thickness of 150nm to 250nm.

4. The ultraviolet and atomic oxygen radiation resistant low solar absorption ratio intelligent thermal control coating according to claim 1, characterized in that The dielectric layer is made of HfO2, CaF2, SiO2, ZnO, TiO2, MgF2, Al2O3 or ZrO2, and has a thickness of 500nm~1000nm.

5. The ultraviolet and atomic oxygen radiation resistant low solar absorption ratio intelligent thermal control coating according to claim 1, characterized in that The VO2 functional layer is VO2 or element-doped VO2, and has a thickness of 30nm to 140nm.

6. The ultraviolet and atomic oxygen radiation resistant low solar absorption ratio intelligent thermal control coating according to claim 1, characterized in that The oxygen-rich protective layer is Al2O3, ZnO, TiO2 or ZrO2, and has a thickness of 50nm~600nm.

7. The ultraviolet and atomic oxygen radiation resistant low solar absorption ratio intelligent thermal control coating according to claim 1, characterized in that The solar reflection layer / ultraviolet shielding layer is made of Si, Ge, ZnSe, ZnS, GaAs, GaP or diamond, and has a thickness of 30nm to 500nm.

8. The method for preparing a UV-resistant and atomic oxygen irradiation-resistant low solar absorption ratio intelligent thermal control coating according to claim 1, characterized in that It is carried out in the following steps:

1. Substrate pretreatment: Polishing, multiple cleaning and drying of the substrate to obtain a pretreated substrate; 2. Preparation of reflective layer: A reflective layer is prepared on one surface of the pretreated substrate by using magnetron sputtering, electron beam evaporation, pulsed laser deposition or atomic layer deposition; 3. Preparation of dielectric layer: A dielectric layer is prepared on the surface of the reflective layer by using magnetron sputtering, electron beam evaporation, pulsed laser deposition or atomic layer deposition; 4. Preparation of VO2 functional layer: A thin film is prepared on the surface of the dielectric layer by magnetron sputtering, electron beam evaporation, pulsed laser deposition or atomic layer deposition, and then post-processed to obtain a VO2 functional layer; 5. Preparation of oxygen-rich protective layer: An oxygen-rich protective layer is prepared on the surface of the VO2 functional layer by using magnetron sputtering, electron beam evaporation, pulsed laser deposition or atomic layer deposition methods; 6. Preparation of solar reflection layer / UV shielding layer: A solar reflection layer / UV shielding layer is prepared on the surface of the oxygen-rich protective layer by using magnetron sputtering, electron beam evaporation, pulsed laser deposition or atomic layer deposition methods, thereby obtaining an intelligent thermal control coating that is resistant to UV and atomic oxygen radiation and has a low solar absorption ratio.

9. The method for preparing a low solar absorption ratio intelligent thermal control coating resistant to ultraviolet and atomic oxygen radiation according to claim 8, characterized in that In step 2, when the reflective layer is Al, the following steps are specifically performed: -3 A reflective layer is prepared on one surface of the pretreated substrate by magnetron sputtering technology under the conditions of 0.4 Pa to 1.5 Pa, a DC power of 100 W to 250 W, a pressure of 0.4 Pa to 1.5 Pa, an argon flow rate of 60 sccm to 100 sccm, and a substrate temperature of room temperature to 200° C.; In step 3, when the dielectric layer is HfO2, the following steps are specifically performed: using a metal Hf target as a target material, in a vacuum degree lower than 1.8×10 -3 A dielectric layer is prepared on the surface of the reflective layer by using magnetron sputtering technology under the conditions of 0.4 Pa ~ 1.5 Pa, working gas pressure of 0.4 Pa ~ 1.5 Pa, argon flow rate of 60 sccm ~ 100 sccm, oxygen flow rate of 1 sccm ~ 10 sccm, substrate temperature of room temperature to 400 ° C and DC power of 100 W ~ 300 W; In step 4, the vacuum degree is lower than 1.5×10 -3 Under the conditions of 1.5-2.0 Pa, frequency of 300Hz~450Hz, pulse width of 45μs~50μs, power of 180W~250W, high-power pulse voltage of 450V~650V, pressure of 0.4Pa~1.2Pa, argon flow rate of 70sccm~95sccm, oxygen flow rate of 0.8sccm~2.4sccm and substrate temperature of 200℃~550℃, a thin film is prepared on the surface of the dielectric layer by using magnetron sputtering technology, and then the temperature is raised to 300℃~600℃ under the conditions of argon flow rate of 60sccm~160sccm and heating rate of 1℃ / min~5℃ / min, and kept warm for 1h~7h under the conditions of argon flow rate of 60sccm~160sccm and temperature of 300℃~600℃, and finally naturally cooled to room temperature to obtain a VO2 functional layer.

10. The method for preparing a UV-resistant and atomic oxygen radiation-resistant low solar absorption ratio intelligent thermal control coating according to claim 8, characterized in that In step 5, when the oxygen-rich protective layer is Al2O3, the steps are as follows: when the vacuum degree is lower than 2.0×10 -3 Under the conditions of 100W~300W DC power, 0.4Pa~1.5Pa pressure, 50sccm~100sccm argon flow rate, 3sccm~10sccm oxygen flow rate and substrate temperature from room temperature to 400℃, an oxygen-rich protective layer was prepared on the surface of the VO2 functional layer by using magnetron sputtering technology; In step 6, when the solar reflection layer / ultraviolet shielding layer is Si, the following steps are specifically performed: -3 Under the conditions of 100W~250W RF power, 0.4Pa~1.2Pa, argon flow rate of 60sccm~100sccm and substrate temperature of room temperature to 400℃, a solar reflection layer / UV shielding layer was prepared on the surface of the oxygen-rich protective layer by using magnetron sputtering technology.

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