Thermal control coating of spacecraft heat radiator and preparation method of thermal control coating

Abstract

The invention relates to the technical field of surface engineering, and particularly provides a thermal control coating of a spacecraft heat radiator and a preparation method of the thermal control coating. A titanium or aluminum oxide adhesion enhancement transition layer with the thickness of 5-20 nm, a silver reflection layer with the thickness of 100-400 nm, an aluminum oxide oxidation inhibition protection layer with the thickness of 50-200 nm and a silicon oxide emissivity regulation and control layer with the thickness of 100-400 nm are sequentially prepared on the surface of a base material through a magnetron sputtering method. The thermal control coating can be applied to the side, facing strong infrared radiation, of a spacecraft, effectively reduces absorption of energy of the wave band of 0.3-25 microns, improves the heat dissipation capacity in the infrared radiation environment, can also be applied to the portion, facing an infrared optical element, of the spacecraft, effectively reduces the influence of thermal radiation of the spacecraft on infrared optical detection, and improves the detection precision. The method is simple, is high in process implementation, can be applied to the surfaces of rigid and flexible base materials such as aluminum alloy, titanium alloy, carbon fiber composite materials and polyimide films, and is suitable for the surfaces of the base materials in various shapes such as planes, curved surfaces and steps.

Description

Technical Field

[0001] The invention relates to the technical field of surface engineering, and in particular to a thermal control coating of a spacecraft thermal radiator and a preparation method thereof. Background Art

[0002] In the space environment, the spacecraft is in a vacuum environment and cannot dissipate heat by convection. Therefore, radiation heat dissipation is the only way to release the heat of the spacecraft. Emissivity is a key parameter that characterizes heat dissipation capacity. The higher the emissivity, the stronger the heat dissipation capacity. When the spacecraft is exposed to sunlight, it will also absorb sunlight energy. Therefore, a low solar absorptivity is also a key parameter that affects the thermal control performance of the coating. Commonly used spacecraft thermal control coatings generally have low solar absorptivity and high emissivity, and have high energy absorption in the infrared band. In a strong infrared radiation environment, the heat dissipation efficiency will be affected due to the absorption of infrared energy. In addition, the infrared waves radiated during the heat dissipation process of the thermal control coating will affect the performance of infrared optical detection devices.

[0003] Therefore, it has become an urgent problem to develop a thermal control coating that can improve the heat dissipation capacity of spacecraft thermal radiators in infrared radiation environments and has good stability under the influence of space environments such as humidity, thermal cycles, ultraviolet radiation, and particle radiation. Summary of the invention

[0004] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a thermal control coating for a spacecraft thermal radiator and a preparation method thereof, which can significantly inhibit the influence of infrared radiation on the heat dissipation capacity of the thermal control coating, and inhibit the influence of the infrared radiation of the thermal control coating on infrared optical detection, thereby improving the heat dissipation capacity of the spacecraft thermal radiator in an infrared radiation environment, and solving the problem of infrared suppression in the process of spacecraft radiation heat dissipation.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] In a first aspect, the present invention provides a thermal control coating for a spacecraft thermal radiator, comprising a substrate, and functional layers sequentially arranged on the surface of the substrate, wherein the functional layers include: an adhesion enhancing transition layer, a reflective layer, an oxidation inhibiting protective layer and an emissivity regulating layer; the adhesion enhancing transition layer is relatively close to the substrate, and the emissivity regulating layer is relatively far away from the substrate.

[0007] Furthermore, the substrate is a rigid and flexible substrate, and the material of the substrate is aluminum alloy, titanium alloy, carbon fiber composite material or polyimide film.

[0008] Furthermore, the surface of the substrate is in various shapes such as a flat surface, a curved surface, or a stepped shape.

[0009] Furthermore, the material of the adhesion enhancing transition layer is titanium or aluminum oxide.

[0010] Furthermore, the thickness of the adhesion enhancing transition layer is 5 to 20 nm.

[0011] Furthermore, the material of the reflective layer is silver.

[0012] Furthermore, the thickness of the reflective layer is 100-400 nm.

[0013] Furthermore, the material of the oxidation inhibition protective layer is aluminum oxide.

[0014] Furthermore, the thickness of the oxidation inhibition protection layer is 50 to 200 nm.

[0015] Furthermore, the material of the emissivity regulating layer is silicon oxide.

[0016] Furthermore, the thickness of the emissivity regulating layer is 100-400 nm.

[0017] Furthermore, the solar absorptivity and emissivity of the thermal control coating are both less than 0.1, and the absorption-emission ratio is 0.8-1.2.

[0018] In a second aspect, the present invention provides a method for preparing a thermal control coating of a spacecraft thermal radiator, the preparation method adopting magnetron sputtering deposition, comprising: using magnetron sputtering to sequentially deposit functional layers on the surface of a substrate with various surface shapes, wherein the functional layers include: an adhesion enhancing transition layer, a reflective layer, an oxidation inhibiting protective layer and an emissivity regulating layer; the adhesion enhancing transition layer is relatively close to the substrate, and the emissivity regulating layer is relatively far away from the substrate.

[0019] Furthermore, the material of the adhesion enhancing transition layer is titanium or aluminum oxide, and the thickness thereof is controlled to be 5 to 20 nm.

[0020] Furthermore, the reflective layer is made of silver, and its thickness is controlled to be 100-400 nm.

[0021] Furthermore, the material of the oxidation inhibition protection layer is aluminum oxide, and the thickness thereof is controlled to be 50 to 200 nm.

[0022] Furthermore, the material of the emissivity regulating layer is silicon oxide, and the thickness thereof is controlled to be 100-400 nm.

[0023] The technical solution of the present invention has the following advantages:

[0024] 1. The thermal control coating provided by the present invention uses magnetron sputtering to sequentially prepare functional layers on the surface of the substrate. From the direction close to the substrate to the direction away from the substrate, the functional layers include: a titanium or aluminum oxide adhesion enhancement transition layer with a thickness of 5 to 20 nm, a silver reflection layer with a thickness of 100 to 400 nm, an aluminum oxide oxidation inhibition protective layer with a thickness of 50 to 200 nm, and a silicon oxide emissivity control layer with a thickness of 100 to 400 nm. The thermal control coating effectively reduces the absorption of energy in the 0.3 to 25 μ m band, the solar absorptivity and emissivity are both less than 0.1, and the absorption-emission ratio is 0.8 to 1.2. It can significantly inhibit the influence of infrared radiation on the heat dissipation capacity of the thermal control coating, and inhibit the influence of infrared radiation of the thermal control coating on infrared optical detection, thereby effectively improving the heat dissipation capacity of the spacecraft thermal radiator in an infrared radiation environment.

[0025] 2. The thermal control coating provided by the present invention can be applied to the side of the spacecraft facing stronger infrared radiation, and can also be applied to the part of the spacecraft facing the infrared optical elements, effectively reducing the impact of its own thermal radiation on infrared optical detection and improving detection accuracy.

[0026] 3. The thermal control coating provided by the present invention has good stability under space environments such as humidity, heat, thermal cycling, ultraviolet radiation, and particle radiation.

[0027] 4. The method of the present invention is simple and has strong process feasibility. It can be applied to rigid and flexible substrate surfaces such as aluminum alloy, titanium alloy, carbon fiber composite material, polyimide film, etc., and is suitable for substrate surfaces of various shapes such as planes, curved surfaces, steps, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 Schematic diagram of the structure of the thermal control coating prepared in an embodiment of the present invention.

[0030] Figure 2 It is a spectrum diagram of the thermal control coating prepared in the embodiment of the present invention. DETAILED DESCRIPTION

[0031] The following examples are provided for a better understanding of the present invention, but are not intended to limit the best mode of implementation, nor to limit the content and protection scope of the present invention. Any product identical or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with other prior arts shall fall within the protection scope of the present invention.

[0032] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in the art can be used. The raw materials or instruments used are all conventional products that can be obtained commercially, including but not limited to the raw materials or instruments used in the examples of this application.

[0033] The following will be combined with the attached Figure 1 and attached Figure 2 , a thermal control coating for a spacecraft thermal radiator and a preparation method thereof provided in an embodiment of the present invention are introduced in detail.

[0034] The technical problem to be solved by the present invention is to overcome the problem that the thermal control coating of the spacecraft thermal radiator in the prior art absorbs high energy in the infrared band, and in a strong infrared radiation environment, the heat dissipation efficiency will be affected due to the absorption of infrared energy, and the infrared waves radiated during the heat dissipation process will affect the performance of infrared optical detection devices. To this end, a thermal control coating of a spacecraft thermal radiator and a preparation method thereof are proposed. The basic principle is: using a magnetron sputtering method, functional layers are sequentially prepared on the surface of substrates of various surface shapes, from the direction close to the substrate to the direction away from the substrate, and the functional layers include: an adhesion enhancement transition layer, a reflection layer, an oxidation inhibition protective layer and an emissivity control layer, wherein the material of the adhesion enhancement transition layer is titanium or aluminum oxide, with a thickness of 5 to 20 nm, the material of the reflection layer is silver, with a thickness of 100 to 400 nm, the material of the oxidation inhibition protective layer is aluminum oxide, with a thickness of 50 to 200 nm, and the material of the emissivity control layer is silicon oxide, with a thickness of 100 to 400 nm. The thermal control coating can be applied to the side of the spacecraft facing stronger infrared radiation, effectively reducing the absorption of energy in the 0.3-25μm band and improving the heat dissipation capacity in an infrared radiation environment. It can also be applied to the part of the spacecraft facing the infrared optical element, effectively reducing the impact of its own thermal radiation on infrared optical detection and improving detection accuracy. The solar absorptivity and emissivity of the thermal control coating prepared by the present invention are both less than 0.1, and the absorption-emission ratio is 0.8-1.2. It has good stability under the influence of space environments such as damp heat, thermal cycles, ultraviolet radiation, and particle radiation. The method of the present invention is simple and has strong process feasibility. It can be applied to rigid and flexible substrate surfaces such as aluminum alloys, titanium alloys, carbon fiber composites, and polyimide films, and is suitable for substrate surfaces of various shapes such as planes, curved surfaces, and steps.

[0035] In a preferred embodiment of the present invention, a method for preparing a thermal control coating of a spacecraft thermal radiator is provided, comprising: taking an aluminum alloy substrate with a surface of a quarter cylinder and a radius of curvature of 100 mm, and pre-treating it for use; using a magnetron sputtering method to prepare an aluminum oxide adhesion enhancing transition layer on the surface of the aluminum alloy substrate, and controlling the thickness of the aluminum oxide adhesion enhancing transition layer to be 10 nm; using a magnetron sputtering method to prepare a silver reflective layer on the surface of the aluminum oxide adhesion enhancing transition layer, and controlling the thickness of the silver reflective layer to be 200 nm; using a magnetron sputtering method to prepare an aluminum oxide oxidation inhibition protective layer on the surface of the silver reflective layer, and controlling the thickness of the aluminum oxide oxidation inhibition protective layer to be 100 nm; using a magnetron sputtering method to prepare a silicon oxide emissivity control layer on the surface of the aluminum oxide oxidation inhibition protective layer, and controlling the thickness of the silicon oxide emissivity control layer to be 200 nm.

[0036] Please refer to Figure 1 The thermal control coating prepared by the method of the preferred embodiment of the present invention has a structure as shown in Figure 1 As shown, it includes: an aluminum alloy substrate, and functional layers deposited in sequence on the surface of the aluminum alloy substrate, the functional layers including: an aluminum oxide adhesion enhancing transition layer with a thickness of 10nm, a silver reflective layer with a thickness of 200nm, an aluminum oxide oxidation inhibition protective layer with a thickness of 100nm, and a silicon oxide emissivity regulating layer with a thickness of 200nm.

[0037] The thermal control coating prepared in the preferred embodiment of the present invention was subjected to spectral testing. The test results are as follows: Figure 2 As shown, for light in the wavelength range of 0.3 to 25 μm, the thermal control coating (structure as shown in Figure 1 The average solar absorptivity of the thermal control coating (as shown) is 0.089 and the average emissivity is 0.093. It can be seen that the method of the embodiment of the present invention and the thermal control coating prepared therefrom can effectively improve the infrared radiation suppression capability, and the solar absorptivity and emissivity are low.

[0038] In summary, the present invention uses magnetron sputtering to sequentially prepare a titanium or aluminum oxide adhesion enhancement transition layer with a thickness of 5 to 20 nm, a silver reflective layer with a thickness of 100 to 400 nm, an aluminum oxide oxidation inhibition protective layer with a thickness of 50 to 200 nm, and a silicon oxide emissivity control layer with a thickness of 100 to 400 nm on the surface of the substrate, which can effectively reduce the absorption of energy in the 0.3 to 25 μm band, improve the heat dissipation capacity in an infrared radiation environment, effectively reduce the influence of self-thermal radiation on infrared optical detection, and improve detection accuracy. The solar absorptivity and emissivity of the thermal control coating prepared by the present invention are both less than 0.1, and the absorption-emission ratio is 0.8 to 1.2, and it has good stability under the action of space environments such as wet heat, thermal cycles, ultraviolet radiation, and particle radiation. The method of the present invention is simple and has strong process feasibility. It can be applied to rigid and flexible substrate surfaces such as aluminum alloys, titanium alloys, carbon fiber composites, and polyimide films, and is suitable for substrate surfaces of various shapes such as planes, curved surfaces, and steps.

[0039] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A thermal control coating for a spacecraft thermal radiator, characterized in that: It includes: a substrate, and functional layers arranged in sequence on the surface of the substrate, wherein the functional layers include: an adhesion enhancing transition layer, a reflective layer, an oxidation inhibiting protective layer and an emissivity regulating layer; the adhesion enhancing transition layer is relatively close to the substrate, and the emissivity regulating layer is relatively far away from the substrate.

2. The thermal control coating for a spacecraft thermal radiator according to claim 1, characterized in that: The substrate is a rigid and flexible substrate, and the material of the substrate is aluminum alloy, titanium alloy, carbon fiber composite material or polyimide film.

3. The thermal control coating for a spacecraft thermal radiator according to claim 1, characterized in that: The material of the adhesion enhancing transition layer is titanium or aluminum oxide, and the thickness of the adhesion enhancing transition layer is 5 to 20 nm.

4. The thermal control coating for a spacecraft thermal radiator according to claim 1, characterized in that: The material of the reflective layer is silver, and the thickness of the reflective layer is 100-400 nm.

5. The thermal control coating for a spacecraft thermal radiator according to claim 1, characterized in that: The material of the oxidation suppression protective layer is aluminum oxide, and the thickness of the oxidation suppression protective layer is 50 to 200 nm.

6. The thermal control coating for a spacecraft thermal radiator according to claim 1, characterized in that: The material of the emissivity regulating layer is silicon oxide, and the thickness of the emissivity regulating layer is 100-400 nm.

7. The thermal control coating for a spacecraft thermal radiator according to claim 1, characterized in that: The solar absorptivity and emissivity of the thermal control coating are both less than 0.1, and the absorption-emission ratio is 0.8-1.

2.

8. The method for preparing a thermal control coating for a spacecraft thermal radiator according to any one of claims 1 to 7, characterized in that: The preparation method adopts magnetron sputtering deposition, including: using magnetron sputtering method to deposit functional layers in sequence on the surface of substrates with various surface shapes, wherein the functional layers include: an adhesion enhancing transition layer, a reflective layer, an oxidation inhibiting protective layer and an emissivity regulating layer; the adhesion enhancing transition layer is relatively close to the substrate, and the emissivity regulating layer is relatively far away from the substrate.

9. The preparation method according to claim 8, characterized in that: The material of the adhesion enhancing transition layer is titanium or aluminum oxide, and its thickness is controlled to be 5 to 20 nm; the material of the reflective layer is silver, and its thickness is controlled to be 100 to 400 nm; the material of the oxidation inhibiting protective layer is aluminum oxide, and its thickness is controlled to be 50 to 200 nm; the material of the emissivity regulating layer is silicon oxide, and its thickness is controlled to be 100 to 400 nm.

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