Radiation protection filler and preparation method thereof as well as radiation protection thermal control coating and component

Abstract

The invention relates to the field of coating protection, and discloses a radiation protection filler, a preparation method and application thereof, a radiation protection thermal control coating and a component. An inner core of the filler comprises Bi2O3, and a shell of the filler comprises Bi4O3 (BO3) 2; or the inner core comprises Bi4O3 (BO3) 2, and the shell comprises Bi3B5O12. According to the preparation method, boric acid is coated on the surface of bismuth oxide by adopting a sol-gel method, a bismuth-rich phase inner core and a boron-rich phase shell layer are formed through sintering in-situ solid-phase reaction by controlling a feeding ratio, and the composite filler with good dispersity and strong binding force is prepared. The filler takes a single particle as a functional element, realizes a synergistic shielding effect of high-Z and low-Z components through chemical bonding, and can effectively attenuate high-energy radiation and inhibit generation of secondary radiation. The filler is used for preparing the radiation protection thermal control coating, has good thermal control performance and radiation protection capacity, avoids the mechanical problem caused by interface internal stress of a multi-layer structure, and is stable and reliable in performance.

Description

Technical Field

[0001] This application relates to the field of coating protection, and more particularly to a radiation protection filler and its preparation method, as well as a radiation protection thermal control coating and component. Background Technology

[0002] The space radiation environment consists of high-energy charged particles generated by Earth's radiation belts, solar activity, and galactic cosmic rays. These particles cause total dose effects, single-event effects, and material structural damage through mechanisms such as ionization damage and displacement damage. Approximately 70% of spacecraft on-orbit failures are related to this, seriously affecting the reliability of long-life space missions.

[0003] Traditional radiation protection methods, such as increasing the thickness of aluminum alloys or adding tantalum sheets, are difficult to widely apply due to satellite weight budget constraints. Single materials such as aluminum, polyethylene, and lead each have their shortcomings when dealing with mixed radiation fields: high-Z (atomic number) materials such as lead and tungsten can effectively shield gamma rays and X-rays, but they can produce secondary cascade showers when encountering high-energy heavy ions, which can actually increase the radiation level inside the cabin; low-Z materials such as polyethylene can effectively block charged particles and slow down neutrons, but they have weak shielding ability against gamma rays and limited absorption capacity for thermal neutrons.

[0004] Therefore, the synergistic protection technology of high and low Z components has become a research focus. Current main technical approaches include physical blending fillers and sandwich-structured coatings. The former has a simple process but suffers from uneven dispersion and weak interfacial bonding; the latter, while possessing good protective potential, may cause coating cracking or peeling due to interfacial stress generated during temperature cycling caused by differences in interlayer thermal expansion coefficients. Summary of the Invention

[0005] In view of this, the purpose of this application is to provide a radiation protection filler and a method for preparing the same, so that the radiation protection filler can effectively attenuate high-energy radiation and suppress the generation of secondary radiation; Another objective of this application is to provide the application of the above-mentioned radiation protection filler in the preparation of radiation protection thermal control coatings, and to provide a radiation protection thermal control coating and a component based on the coating, which has both good thermal control performance and radiation protection capability, while avoiding mechanical problems caused by interfacial stress in multilayer structures.

[0006] To solve the aforementioned technical problems / achieve the aforementioned objectives, or at least partially solve the aforementioned technical problems / achieve the aforementioned objectives, as a first aspect of this application, a radiation protection filler is provided, which has a core-shell structure, wherein the core comprises Bi2O3 and the outer shell comprises Bi4O3(BO3)2; or the core comprises Bi4O3(BO3)2 and the outer shell comprises Bi3B5O3. 12 .

[0007] Optionally, the B / Bi atomic ratio is not greater than 1:0.6.

[0008] As a second aspect of this application, a method for preparing radiation protection filler as described in this application is provided, comprising: Obtain a uniformly dispersed bismuth oxide suspension; The bismuth oxide suspension was mixed with boric acid and then gelled. The gelled mixture is aged and then calcined to obtain the radiation protection filler.

[0009] Optionally, the gelation includes adding urea, citric acid, or polyethylene glycol as an additive.

[0010] Optionally, the calcination temperature is 500-600℃. More preferably, the calcination is performed in stages, with the first calcination temperature at 300-400℃ and the second calcination temperature at 500-600℃.

[0011] Optionally, the molar ratio of boric acid to bismuth oxide is not greater than 3.33:1.

[0012] As a third aspect of this application, a radiation protection thermal control coating is provided, comprising the radiation protection filler described in this application, as well as a polymer resin, an organic solvent, and a curing agent.

[0013] Optionally, by weight, it includes 10-30 parts of polymer resin, 30-50 parts of organic solvent, 0.3-0.5 parts of curing agent, and 40-60 parts of the radiation protection filler described in this application.

[0014] As a fourth aspect of this application, a component is provided, including a substrate and a radiation protection thermal control coating disposed on the surface of the substrate; the radiation protection thermal control coating is formed by curing the radiation protection thermal control coating described in this application.

[0015] This application employs a sol-gel method to coat boric acid onto the surface of bismuth oxide. By controlling the feed ratio and sintering, an in-situ solid-state reaction is formed to create a bismuth-rich core and a boron-rich shell, resulting in a composite filler with good dispersibility and strong bonding. This filler uses individual particles as functional units, achieving a synergistic shielding effect between high-Z and low-Z components through chemical bonding. This effectively attenuates high-energy radiation and suppresses secondary radiation generation. The filler described in this application, used in the preparation of radiation protection thermal control coatings, combines excellent thermal control performance with radiation protection capabilities, while avoiding mechanical problems caused by interfacial stress in multilayer structures, exhibiting stable and reliable performance. Attached Figure Description

[0016] Figure 1 The diagram shown is a schematic representation of the structure of the radiation control packing material of this application. Figure 2The image shown is the XRD pattern of the radiation control packing material of Embodiment 1 of this application; Figure 3 The image shown is the XRD pattern of the radiation control packing material of Embodiment 2 of this application. Detailed Implementation

[0017] This application discloses a radiation protection filler and its preparation method, as well as a radiation protection thermal control coating and components. Those skilled in the art can refer to the content of this document and appropriately modify the process parameters to achieve the desired results. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this application. The products, processes, and applications described in this application have been described through preferred embodiments. Those skilled in the art can obviously modify or appropriately change and combine the preparation methods described herein without departing from the content, spirit, and scope of this application to realize and apply the technology of this application. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without creative effort are within the scope of protection of this application.

[0018] It should be noted that, in this document, relational terms such as "first" and "second," "step 1" and "step 2," and "(1)" and "(2)" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. Moreover, the embodiments and features described in this application can be combined with each other without conflict.

[0019] Existing radiation protection coatings typically employ physically blended high- and low-Z fillers or multilayer composite structures, which suffer from problems such as uneven filler dispersion, weak interfacial bonding, and high interlayer stress and easy cracking and peeling due to mismatched thermal expansion coefficients. Addressing these shortcomings, this application provides a novel radiation protection filler designed from the perspective of filler microstructure, aiming to construct individual particles as independent functional units. This novel filler, through microstructure control, achieves close synergy between bismuth-rich and boron-rich high-Z and low-Z components, improving protective effectiveness while maintaining lightweight characteristics.

[0020] In the first aspect of this application, the provided radiation protection filler is a core-shell structure, as shown in the schematic diagram. Figure 1 The core comprises Bi2O3, and the shell comprises Bi4O3(BO3)2; or the core comprises Bi4O3(BO3)2, and the shell comprises Bi3B5O3. 12 The core is a bismuth-rich region with a high Z composition, while the outer shell is a boron-rich region with a low Z composition. The bismuth-rich phase, as the high Z core, plays a crucial role in efficiently absorbing γ / X-ray photons softened by the outer shell and ultimately stopping the decelerated charged particles. The boron-rich phase, as the low Z outer shell, plays a crucial role in softening incident photons through Compton scattering, decelerating charged particles through ionization loss, and using boron to capture and remove secondary neutrons in situ. The two phases are tightly coupled in space, achieving a synergistic protection path of "softening / decelerating first, then absorbing / stopping."

[0021] This radiation protection filler integrates the synergistic shielding effect of high-Z and low-Z components into a single filler particle, achieving efficient attenuation of various types of radiation and effectively suppressing the generation of secondary radiation. Furthermore, the core and shell are strongly bonded by chemical bonds, resulting in strong adhesion and avoiding interface problems caused by physical mixing. The integrated structure eliminates the thermal mismatch stress of multilayer materials, thus resolving the risk of cracking and peeling of subsequent coatings, ensuring stable and reliable performance.

[0022] In some embodiments of this application, the B / Bi atomic ratio is not greater than 1:0.6, for example, 1:0.61, 1:0.65, 1:0.70, 1:0.75, 1:0.80, 1:0.85, 1:90, 1:0.95, 1:1, 1:1.15, 1:1.20, 1:1.25, 1:1.30, 1:1.35, 1:1.40, 1:1.45, 1:1.50, 1:1.55, 1:1.60, 1:1.65, 1:1.70, 1:1.75, 1:1.80, 1:1.85, 1:1.90, 1:1.95, 1:2.0, 1:2.5, 1:3, 1:5, 1:10, 1:50, 1:100, or any value between any two. In some other embodiments of this application, when 1:2 ≤ B / Bi atomic ratio < 1:0.6, the core of the radiation protection filler is Bi4O3(BO3)2, and the outer shell is Bi3B5O. 12 When the B / Bi atomic ratio is <1:2, the radiation protection filler in this application has a core of Bi2O3 and a shell of Bi4O3(BO3)2.

[0023] In a second aspect of this application, a method for preparing the radiation protection filler as described in this application is provided, comprising: Obtain a uniformly dispersed bismuth oxide suspension; The bismuth oxide suspension was mixed with boric acid and then gelled. The gelled mixture is aged and then calcined to obtain the radiation protection filler.

[0024] In some embodiments of this application, a uniformly dispersed bismuth oxide suspension can be obtained by thorough stirring in a solvent containing a dispersant, such as water, and, if necessary, by further ultrasonic treatment to assist dispersion. The dispersant includes, but is not limited to, polyvinylpyrrolidone, polyethylene glycol, and polysorbate-80.

[0025] In some embodiments of this application, the gelation process includes continuous stirring under heating conditions until the solvent evaporates and the system gels, wherein the heating temperature can be selected as 70-90°C. In other embodiments of this application, the gelation includes adding a pH-release agent such as urea to adjust the pH, adding a gelation promoter such as citric acid, or adding a physical template such as polyethylene glycol to assist in gelation.

[0026] In some embodiments of this application, the aging process includes standing at a suitable temperature, for example, 15-35°C.

[0027] In some embodiments of this application, the calcination temperature is preferably 500-600℃. Too low a calcination temperature may lead to insufficient decomposition and melting of the precursor, and insufficient atomic diffusion motive force; too high a temperature may cause the boron component to volatilize, damaging the core-shell structure. In other embodiments of this application, the calcination is performed in stages: the first stage involves heating and holding to achieve melting and uniform coating of boron oxide (during the heating process, boric acid dehydrates to form boron oxide) and removes additives; the second stage controls diffusion to form the core-shell structure. In other embodiments of this application, the first calcination temperature is 300-400℃, the heating rate is 1-5℃ / min, and the holding time is 60-90min; the second calcination temperature is 500-600℃, the heating rate is 5-10℃ / min, and the holding time is 60-150min.

[0028] In some embodiments of this application, the molar ratio is no greater than 3.33:1, for example, 0.1:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2.0:1, 2.1:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, 2.6:1, 2.7:1, 2.8:1, 2.9:1, 3.0:1, 3.1:1, 3.2:1, 3.3:1, 3.32:1, or any value between any two. This application found through testing at different feed ratios that a radiation protection filler with a bismuth-rich core and a boron-rich shell can be generated under this molar ratio condition; see Table 1 below for the results. Table 1

[0029] Based on the results of a series of different feed ratios recorded in Table 1, when the molar ratio of boric acid to bismuth oxide is not greater than 3.33:1, the two core-shell structure fillers described above in this application can be produced. However, when the molar ratio is greater than or equal to 3.33:1, the resulting core-shell structure Bi3B5O... 12 + The core of BiB3O6 is not a bismuth-rich phase.

[0030] In some other embodiments of this application, the bismuth oxide is 10-20 parts by weight, and the boric acid is 0.5-5 parts by weight, for example, 12 parts of bismuth oxide and no more than 5.31 parts of boric acid. Furthermore, other dispersants, gelling aids, and solvents can be adjusted according to actual conditions. In some other embodiments of this application, the dispersant is 1-2 parts by weight, the solvent is 100-200 parts by weight, and the gelling aid is 0.5-10 parts by weight.

[0031] In some embodiments of this application, the preparation method includes the following: I. Preparation of suspension: (1) Dissolve the dispersant in deionized water and stir until clear, with the following parameters: Dispersant: Polyvinylpyrrolidone Dissolution temperature: 20 ~ 40℃ Dosage of each component: 1-2 parts of polyvinylpyrrolidone; 100-200 parts of deionized water.

[0032] (2) Under mechanical stirring and with the assistance of glass beads, bismuth oxide powder is added in batches to the solution obtained in step (1), and stirring is continued. The parameters are as follows: Stirring speed: 1200 ~ 1400 rpm Mixing time: 60 ~ 180 min Bismuth oxide particle size: 0.5 ~ 5 μm Dosage of each component: 10-20 parts of bismuth oxide powder (3) Filter the solution obtained in step (2) and sonicate it to obtain a uniform and stable yellow bismuth oxide suspension with the following parameters: Ultrasound duration: 60 ~ 180 min II. Gel-coating: (4) Add boric acid to the bismuth oxide suspension obtained in step (3) and stir until the boric acid is completely dissolved and evenly dispersed, with the following parameters: Stirring temperature: 70 ~ 90℃ Stirring speed: 100 ~ 400 rpm Mixing time: 10 ~ 30 min Dosage of each component: Boric acid 0.5 ~ 5 parts (5) Add the gelation aid to the mixed solution obtained in step (4), and stir until completely dissolved and evenly dispersed, with the following parameters: Gelation aid: Urea Stirring temperature: 70 ~ 90℃ Stirring speed: 100 ~ 400 rpm Mixing time: 10 ~ 30 min Dosage of each component: 0.5-10 parts of urea (6) Under heating conditions, the mixed solution in step (5) is continuously stirred. The water gradually evaporates and the system gels, thereby coating the surface of the bismuth oxide particles with a boric acid layer. The parameters are as follows: Stirring speed: 100 ~ 400 rpm Stirring temperature: 70 ~ 90℃ Mixing time: 150 ~ 300 min (7) After aging, the gel obtained in step (6) is ground into a light yellow powder.

[0033] Aging temperature: 15 ~ 35℃ Aging time: 420 ~ 540 min III. In-situ solid-phase reaction: (8) The above powder is sintered in a muffle furnace in two steps. The heating parameters for the first stage are as follows: Heating rate: 1 ~ 5℃ / min Insulation temperature: 300 ~ 400℃ Keep warm for: 60 ~ 90 minutes (9) The heating parameters for the second stage are as follows: Heating rate: 5 ~ 10℃ / min Insulation temperature: 500 ~ 600℃ Heat preservation time: 60 ~ 150 min (10) Cool to room temperature with the furnace and grind to obtain the final white filler - radiation protection filler of this application.

[0034] In a third aspect of this application, a radiation protection thermal control coating is provided, comprising the radiation protection filler described in this application, as well as a polymer resin, an organic solvent, and a curing agent.

[0035] In some embodiments of this application, the radiation protection thermal control coating comprises, by weight, 10-30 parts of polymer resin, 30-50 parts of organic solvent, 0.3-0.5 parts of curing agent, and 40-60 parts of the radiation protection filler described in this application.

[0036] In some embodiments of this application, the polymer resin may be a polysiloxane or epoxy resin, such as R107 silicone rubber or DC93-500 silicone rubber; the organic solvent may be an ester solvent, an aliphatic hydrocarbon solvent, or an aromatic hydrocarbon solvent, such as ethyl acetate, butyl acetate, cyclohexane, n-heptane, toluene, or xylene; and the curing agent may be tetraethyl orthosilicate or methyltrimethoxysilane. In a fourth aspect of this application, a component is provided, comprising a substrate and a radiation protection thermal control coating disposed on the surface of the substrate; the radiation protection thermal control coating is formed by curing the radiation protection thermal control coating described in this application. The component includes, but is not limited to, components such as a spacecraft's space robotic arm, solar array steering mechanism, and docking mechanism. The material of the component can be a metal such as aluminum alloy, titanium alloy, magnesium alloy, zinc alloy, zirconium alloy, or stainless steel, or a material with other metal platings electroplated on the surface of these metal materials, such as a nickel plating; more specifically, it can be MB15 / Ni material.

[0037] In some embodiments of this application, to improve the adhesion of the coating to the substrate surface, the surface of the substrate may be roughened, for example, by sandblasting. The radiation protection thermal control coating of this application, after testing, exhibits a solar absorptivity (αS) of approximately 0.14 and a hemispherical emissivity (εH) of approximately 0.91, demonstrating excellent thermal control performance. Simultaneously, it exhibits a high attenuation coefficient for various energy levels of gamma rays, proving its excellent radiation shielding capability and successfully achieving integrated thermal management and radiation protection functions.

[0038] In the comparative experiments provided in this application, unless otherwise specified, all experimental conditions and materials are kept consistent to ensure comparability. Unless otherwise specified, all experimental materials and reagents used in the examples are commercially available.

[0039] The following provides further details regarding a radiation protection filler, its preparation method, its application, as well as radiation protection thermal control coatings and components provided in this application.

[0040] Example 1: (1) Disperse 6.0 g of polyvinylpyrrolidone in 600 mL of deionized water and stir at 40 °C for 20 min until completely dissolved and clear; (2) Under mechanical stirring at 1300 rpm and in the presence of an appropriate amount of glass beads, 60 g of bismuth oxide powder was slowly added in batches and stirred continuously for 150 min. (3) Filter to remove glass beads, and sonicate the filtrate for 120 min to obtain a uniform and stable yellow liquid. (4) Add 18 g of boric acid to the bismuth oxide suspension obtained in step (3), stir at 80 °C for 20 min until the boric acid is completely dissolved and evenly dispersed; (5) Continue to add 18 g of urea to the solution in step (4) and stir continuously at 80 °C for 20 min; (6) Stirring was continued at 80°C and 400 rpm. As the water gradually evaporated, the viscosity of the system increased and eventually a uniform gel was formed, thus achieving the coating of boric acid on the surface of bismuth oxide particles. (7) The gel obtained in step (6) was statically aged at 25°C for 480 min. After the aging was completed, it was ground to obtain a light yellow precursor powder.

[0041] (8) Place the precursor powder obtained in step (7) in a muffle furnace and perform two-step sintering in an air atmosphere: first, heat the powder from room temperature to 400 ℃ at a rate of 3 ℃ / min and hold it for 50 min; (9) Then raise the temperature to 600 ℃ at a rate of 5 ℃ / min and hold for 90 min; (10) After the process is completed, the furnace is cooled to room temperature, then removed and ground to obtain a white core-shell structured filler. (11) Add 20g of glass beads and 20g of R107 resin to 40g of butyl acetate and stir until homogeneous; (12) Add 60g of the filler from step (10) and 0.4g of tetraethyl orthosilicate to the mixed solution from step (11), and stir for 180min at 1300rpm. (13) Sandblasting is performed on the surface of MB15 / Ni material. The abrasive type is 80 mesh alumina, the air source pressure is 0.04MPa, the distance between the spray gun and the part is 20cm, and sandblasting is performed once. After sandblasting, the surface of the test piece is cleaned. (14) Add 0.6g of tetraethyl orthosilicate and 0.4g of dibutyltin dilaurate to the coating paint obtained in step (12) and stir until uniform; (15) Spray the paint from step (14) onto the surface of the test piece obtained in step (13); (16) The sample from step (15) was baked at 55°C for 48 hours to obtain a radiation protection thermal control coating.

[0042] The following tests were performed on the coating filler prepared in this embodiment: 1) Microstructure and elemental composition: SEM results showed that the surface roughness of the filler increased significantly after in-situ solid-phase reaction, which helped to enhance its mechanical interlocking with the film-forming material, thereby improving the mechanical properties of the coating. The filler particle size distribution was 1~5 μm, and EDS energy dispersive spectroscopy analysis confirmed that it was composed of three elements: Bi, B, and O, with a Bi / B atomic ratio of 1:1.13.

[0043] 2) Phase structure analysis: XRD pattern shows ( Figure 2 The packing shell is Bi3B5O. 12 The core is Bi4O3(BO3)2. This result confirms, from a crystallographic perspective, the successful recombination and chemical bonding of the high and low Z components in the core-shell structure.

[0044] The following tests were performed on the coating prepared in this embodiment: 1) The thermal radiation performance of the obtained coating was tested, and the results showed that the solar absorptivity αS was about 0.14 and the hemispherical emissivity εH was about 0.91.

[0045] 2) The radiation protection performance of the obtained coating was tested using a Ge-γ spectrometer system. The results showed that when the photon energy was 86.5 keV, the linear attenuation coefficient of the coating under X-ray irradiation was 1.68 cm⁻¹. 2 / g; at a photon energy of 105.3 keV, the mass decay coefficient of the coating under X-ray irradiation is 1.58 cm⁻¹. 2 / g; at a photon energy of 661 keV, the mass decay coefficient of the coating under X-ray irradiation is 0.89 cm⁻¹. 2 / g, which has good shielding performance.

[0046] Example 2: (1) Disperse 6.0 g of polyvinylpyrrolidone in 600 mL of deionized water and stir at 40 °C for 20 min until completely dissolved and clear; (2) Under mechanical stirring at 1300 rpm and in the presence of an appropriate amount of glass beads, 60 g of bismuth oxide powder was slowly added in batches and stirred continuously for 150 min. (3) Filter to remove glass beads, and sonicate the filtrate for 120 min to obtain a uniform and stable yellow liquid. (4) Add 12g of boric acid to the bismuth oxide suspension obtained in (3), stir at 80 °C for 20 min until the boric acid is completely dissolved and evenly dispersed; (5) Continue to add 12 g of urea to the solution in (4) and stir continuously at 80 °C for 20 min; (6) Stirring was continued at 80°C and 400 rpm. As the water gradually evaporated, the viscosity of the system increased and eventually a uniform gel was formed, thus achieving the coating of boric acid on the surface of bismuth oxide particles. (7) The obtained gel was statically aged at 25°C for 480 min, and then ground to obtain a light yellow precursor powder.

[0047] (8) Place the precursor powder in a muffle furnace and sinter it in two steps under an air atmosphere: first, heat it from room temperature to 400 ℃ at a rate of 3 ℃ / min and hold it for 50 min; (9) Then raise the temperature to 600 ℃ at a rate of 5 ℃ / min and hold for 90 min; (10) After the process is completed, the furnace is cooled to room temperature, then removed and ground to obtain a white core-shell structured filler. (11) Add 20g of glass beads and 20g of R107 resin to 40g of butyl acetate and stir until homogeneous; (12) Add 60g of the filler from step (10) and 0.4g of tetraethyl orthosilicate to the mixed solution of (11), and stir for 180min at a speed of 1300rpm. (13) Sandblasting is performed on the surface of MB15 / Ni material. The abrasive type is 80 mesh alumina, the air source pressure is 0.04MPa, the distance between the spray gun and the part is 20cm, and sandblasting is performed once. After sandblasting, the surface of the test piece is cleaned. (14) Add 0.6g of tetraethyl orthosilicate and 0.4g of dibutyltin dilaurate to the coating paint obtained in (12) and stir until homogeneous; (15) Spray the paint from step (14) onto the surface of the test piece obtained in step (13); (16) The sample from step (15) was baked at 55°C for 48 hours to obtain a radiation protection thermal control coating.

[0048] The following tests were performed on the coating filler prepared in this embodiment: 1) Microstructure and elemental composition: SEM results showed that the surface roughness of the filler increased significantly after in-situ solid-phase reaction, which helped to enhance its mechanical interlocking with the film-forming material, thereby improving the mechanical properties of the coating. The filler particle size distribution was 1~4 μm, and EDS energy dispersive spectroscopy analysis confirmed that it was composed of three elements: Bi, B, and O, with a Bi / B atomic ratio of 1.33:1.

[0049] 2) Phase structure analysis: XRD pattern shows ( Figure 3 The packing shell is Bi3B5O. 12 The core is Bi4O3(BO3)2. This result confirms, from a crystallographic perspective, the successful recombination and chemical bonding of the high and low Z components in the core-shell structure.

[0050] The following tests were performed on the coating prepared in this embodiment: 1) The thermal radiation performance of the obtained coating was tested, and the results showed that the solar absorptivity αS was about 0.17 and the hemispherical emissivity εH was about 0.89.

[0051] 2) The radiation protection performance of the obtained coating was tested using a Ge-γ spectrometer system. The results showed that when the photon energy was 86.5 keV, the linear attenuation coefficient of the coating under X-ray irradiation was 1.65 cm⁻¹. 2 / g; at a photon energy of 105.3 keV, the mass decay coefficient of the coating under X-ray irradiation is 1.56 cm⁻¹. 2 / g; at a photon energy of 661 keV, the mass decay coefficient of the coating under X-ray irradiation is 0.88 cm⁻¹. 2 / g, which has good shielding performance.

[0052] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A radiation protection filler, characterized in that, The structure is a core-shell structure, wherein the core comprises Bi2O3 and the shell comprises Bi4O3(BO3)2; or the core comprises Bi4O3(BO3)2 and the shell comprises Bi3B5O3. 12 .

2. The radiation protection filler according to claim 1, characterized in that, The B / Bi atomic ratio is no greater than 1:0.

6.

3. A method for preparing the radiation protection filler as described in claim 1, characterized in that, include: Obtain a uniformly dispersed bismuth oxide suspension; The bismuth oxide suspension was mixed with boric acid and then gelled. The gelled mixture is aged and then calcined to obtain the radiation protection filler.

4. The preparation method according to claim 3, characterized in that, The gelation process includes adding urea, citric acid, or polyethylene glycol as an additive.

5. The preparation method according to claim 3, characterized in that, The calcination temperature is 500-600℃.

6. The preparation method according to claim 3 or 5, characterized in that, The calcination is carried out in stages, with the first calcination temperature at 300-400℃ and the second calcination temperature at 500-600℃.

7. The preparation method according to claim 3, characterized in that, The molar ratio of boric acid to bismuth oxide is no greater than 3.33:

1.

8. A radiation protection thermal control coating, characterized in that, It includes the radiation protection filler as described in any one of claims 1-3, as well as polymer resin, organic solvent, and curing agent.

9. The radiation protection thermal control coating according to claim 8, characterized in that, By weight, it comprises 10-30 parts polymer resin, 30-50 parts organic solvent, 0.3-0.5 parts curing agent, and 40-60 parts radiation protection filler as described in any one of claims 1-2.

10. A component, characterized in that, It includes a substrate and a radiation protection thermal control coating disposed on the surface of the substrate; the radiation protection thermal control coating is formed by curing the radiation protection thermal control coating as described in claim 8 or 9.

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