High-temperature-resistant structure with multi-infrared-band and microwave stealth functions and preparation method of high-temperature-resistant structure

Abstract

The invention discloses a high-temperature-resistant structure with multiple infrared bands and a microwave stealth function and a preparation method of the high-temperature-resistant structure. Comprising a microwave absorption layer and an infrared selective radiation layer, the short-wave infrared emissivity at 700 DEG C is smaller than 0.6, the emissivity of medium-wave infrared and long-wave infrared is smaller than 0.5, the emissivity of 5-8 microns is larger than 0.5, and the X-waveband reflection loss exceeds-3dB; the microwave absorption layer is of a metasurface structure and is composed of a conductive ceramic backboard layer, a dielectric layer and a periodic high-temperature-resistant conductive ceramic patch layer. The infrared selective radiation layer is of a multi-layer structure, is composed of a substrate, an adhesion layer, a metal reflection layer, a resonant cavity layer, an ultra-thin metal layer, a 5-8 [mu] m antireflection layer and a protection layer, and is subjected to laser etching. The material structure disclosed by the invention has efficient radiation heat dissipation capability while realizing multi-infrared band and microwave stealth, and can be widely applied to high-temperature scenes in the fields of aviation, aerospace and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of stealth materials, and particularly to a structure capable of achieving multi-infrared band (short-wave infrared, mid-wave infrared, long-wave infrared) and microwave stealth functions in a high-temperature environment and a preparation method thereof, and having high-efficiency radiation heat dissipation ability. Background Art

[0002] In the field of aerospace, with the increasingly complex mission environment and the continuous increase in the speed of aircraft, aircraft often operate under high-temperature conditions. This makes its radiation in multiple infrared bands significantly enhanced and easily captured by infrared detectors. In addition, with the development of multi-spectral detection technology, radar systems and infrared detection systems are often combined to detect targets in a wider frequency range. Therefore, studying materials for multi-infrared band and microwave stealth is of great significance for improving the concealment and survivability of aircraft. At the same time, considering that aircraft are long-term faced with extreme thermal environments, it is necessary to reasonably regulate their infrared radiation performance to prevent excessive temperature and ensure the safe operation of aircraft.

[0003] At high temperatures, the infrared radiation intensity of the aircraft becomes higher and the radiation peak blue-shifts. In addition to the traditional infrared detection bands: mid-wave infrared (3 - 5μm) and long-wave infrared (8 - 14μm), the radiation intensity in the short-wave infrared (1.4 - 2.5μm) band is also extremely intense, making the aircraft extremely easy to be captured by infrared detectors. It is necessary to suppress the infrared radiation signal in these bands to achieve stealth; the main means is to reduce the surface temperature or reduce the surface emissivity. In addition, the detection of microwave radar also poses a great threat to the survival of aircraft. It mainly locates the target by emitting electromagnetic waves (X band, 8 - 12GHz) and detecting the reflected echo of the target. It is necessary to suppress the reflected wave received by the radar to achieve concealment; the main means to achieve stealth is to absorb the radar waves incident on the surface of the aircraft or scatter them to the direction where the radar cannot receive radar waves.

[0004] Under the dual action of a large amount of heat generated by itself and severe aerodynamic heating from the outside, the temperature of a high-speed aircraft will rise rapidly and remain in a high-temperature environment for a long time. This not only easily leads to a decline in material performance and structural damage, affecting its safe operation, but also affects the stealth performance of the aircraft. Utilizing the characteristic of intense infrared radiation at high temperatures, reasonably regulating its infrared spectrum can achieve high-efficiency radiation heat dissipation in the non-atmospheric window (5 - 8μm).

[0005] The existing stealth technologies that are compatible with infrared and microwave bands at high temperatures mainly aim at stealth detection in the mid-wave infrared and long-wave infrared bands. For example, a high-temperature radar and infrared-compatible stealth material based on frequency selective surface and its preparation method (CN106003864A), a broadband wave-absorbing high-temperature radar and infrared-compatible coating and its preparation method (CN118854210A), a radar / infrared-compatible stealth coating that can withstand a temperature of 600°C and its preparation method (CN107747080A), a high-temperature radar-infrared-compatible stealth coating with a functionally gradient distribution and its preparation method (CN112961531A). The deficiencies of the existing technologies are as follows: (1) Stealth in the short-wave infrared band is not considered; (2) Radiative heat dissipation through non-atmospheric windows is not considered, and its potential heat dissipation power can reach 17.2 kW / m 2 at 700°C; (3) There are problems such as relatively complex preparation processes.

[0006] In summary, the existing high-temperature infrared and microwave stealth technologies cannot simultaneously cover highly threatening infrared detection bands such as short-wave infrared, mid-wave infrared, and long-wave infrared, and cannot make full use of non-atmospheric transparent windows for radiative heat dissipation. Therefore, how to design a material structure that can achieve infrared multi-band and microwave stealth and has high-efficiency radiative heat dissipation ability in a high-temperature environment is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0007] To solve the problems existing in the prior art, the present invention provides a structure with high-temperature resistance, multi-infrared band and microwave stealth, and high-efficiency radiative heat dissipation functions and its preparation method, which can achieve compatible stealth in the short-wave infrared, mid-wave infrared, and long-wave infrared bands as well as the microwave band, and perform effective radiative heat dissipation in non-atmospheric windows.

[0008] The material of the present invention can achieve infrared and microwave stealth for high-temperature targets and has an effective radiative heat dissipation ability, and can be widely applied in the fields of aviation, aerospace, etc.

[0009] The technical solution adopted by the present invention is as follows:

[0010] The present invention includes a microwave absorption layer composed of a conductive ceramic backplane layer, a dielectric layer, and a periodic conductive ceramic patch layer arranged in sequence from inside to outside or from bottom to top, and an infrared selective radiation layer composed of a substrate, an adhesion layer, a metal reflection layer, a resonant cavity layer, an ultra-thin metal layer, a 5-8 μm antireflection layer, and a protective layer; it satisfies:

[0011] The infrared light emissivity (or emissivity) in the 1.4-2.5 μm band is less than 0.6 at 700°C;

[0012] The infrared light emissivity in the 3-5 μm and 8-14 μm bands is less than 0.5 at 700°C;

[0013] The infrared emissivity in the 5 - 8μm band is higher than 0.5 at 700°C;

[0014] The microwave reflection loss in the 9.6 - 12GHz band exceeds - 3dB at 700°C;

[0015] In the above structure, the microwave absorption layer is used to achieve high reflection loss in the X - band (8 - 12GHz); the infrared selective radiation layer is used to achieve low emissivity in the short - wave infrared, mid - wave infrared and long - wave infrared bands and high emissivity in the 5 - 8μm band. Among them, the adhesion layer is used to improve the adhesion between the multi - layer film and the substrate; the metal reflection layer and the ultra - thin metal layer are used to achieve low emissivity in the short - wave infrared, mid - wave infrared and long - wave infrared bands and absorb infrared light in the 5 - 8μm band; the resonant cavity layer and the 5 - 8μm antireflection layer are used to achieve high emissivity in the 5 - 8μm band; the protective layer is used to prevent water vapor in the air from invading the multi - layer film and damaging the film structure at high temperatures.

[0016] Preferably, the conductive ceramic backplane layer is one of high - temperature - resistant conductive ceramics such as zirconium boride, titanium boride, hafnium boride, titanium carbide, etc., and more preferably titanium boride.

[0017] Preferably, the thickness of the conductive ceramic backplane layer is greater than 0.5mm. More preferably, the thickness of the electro - ceramic backplane layer is further preferably 1 - 3mm.

[0018] Preferably, the dielectric layer is one of high - temperature - resistant dielectrics such as alumina, silica, hafnium oxide, tantalum oxide, ytterbium silicate, sodium silicate, etc., and more preferably alumina.

[0019] Preferably, the thickness of the dielectric layer is 0.5 - 5mm. More preferably, the thickness of the dielectric layer is further preferably 0.8 - 4mm.

[0020] Preferably, the periodic conductive ceramic patch layer is one of high - temperature - resistant conductive ceramics such as zirconium boride, titanium boride, hafnium boride, titanium carbide, etc. More preferably titanium boride.

[0021] Preferably, for the periodic conductive ceramic patch layer, the ceramic patch period is 1 - 20mm, further preferably 5 - 15mm. The thickness is 0.2 - 1.2mm, further preferably 0.4 - 0.8mm. The shape is geometric patterns such as square, rectangle, ring, etc. or a combination of multiple patterns. More preferably square.

[0022] Preferably, the conductive ceramic backplane layer, the dielectric layer and the periodic conductive ceramic patch layer are fixed by a high - temperature - resistant adhesive to form a microwave absorption layer; the high - temperature - resistant adhesive is an inorganic adhesive mainly composed of aluminosilicate.

[0023] Preferably, the adhesion layer is titanium or chromium metal. More preferably, it is titanium.

[0024] Preferably, the thickness of the adhesion layer is 1 - 10 nm. More preferably, the thickness of the adhesion layer is further preferably 2 - 8 nm.

[0025] Preferably, the metal reflection layer is one of high-temperature resistant metals such as platinum, iridium, palladium, tungsten, molybdenum, etc. More preferably, it is molybdenum.

[0026] Preferably, the thickness of the metal reflection layer is greater than 20 nm. Further preferably, it is 40 - 100 nm.

[0027] The resonant cavity layer is an infrared transparent and high-temperature resistant material such as germanium, silicon, barium fluoride, calcium fluoride, magnesium fluoride, zinc sulfide, etc. More preferably, it is silicon. The thickness of the resonant cavity layer is 200 - 1200 nm. Further preferably, it is 400 - 800 nm.

[0028] Preferably, the ultra-thin metal layer is one of high-temperature resistant metals such as platinum, iridium, palladium, tungsten, molybdenum, etc. Further preferably, it is molybdenum. The thickness of the ultra-thin metal layer is 1 - 25 nm. Further preferably, it is 10 - 20 nm.

[0029] The 5 - 8 μm anti-reflection layer is an infrared transparent and high-temperature resistant material such as germanium, silicon, barium fluoride, calcium fluoride, magnesium fluoride, zinc sulfide, etc. More preferably, it is silicon. The thickness of the 5 - 8 μm anti-reflection layer is 200 - 1200 nm. Further preferably, it is 400 - 800 nm.

[0030] The material of the protective layer is a dense high-temperature resistant material such as chromium oxide or aluminum oxide, etc. More preferably, it is aluminum oxide. The thickness of the protective layer is 5 - 50 nm. Further preferably, it is 10 - 40 nm.

[0031] Preferably, the infrared selective radiation layer needs to be processed by laser etching. The etching period is 0.2 - 5 mm, more preferably 0.4 - 3 mm. The etching line width is 10 - 100 μm. Further preferably, it is 10 - 30 μm. The etching pattern is periodic horizontal and vertical lines. The horizontal and vertical lines are generally perpendicular to each other, and can be equally spaced or unequally spaced. Generally, equally spaced setting is adopted.

[0032] Preferably, the infrared selective radiator further includes a substrate for mechanical support and allowing microwave transmission.

[0033] As a further preference, the substrate material is a high-temperature resistant and wave-transparent material, including but not limited to one or more of silicon, silicon dioxide, aluminum oxide, tantalum oxide, etc. More preferably, it is aluminum oxide.

[0034] As a further preference, the thickness of the substrate needs to be selected considering the impedance matching of the overall structure, and is further preferably 1 - 5 mm.

[0035] A preparation method for the high-temperature resistant structure with multi-infrared band and microwave stealth functions as described in any one of the above, comprising:

[0036] (1) Depositing an adhesion layer, a metal reflection layer, a resonant cavity layer, an ultra-thin metal layer, a 5 - 8 μm anti-reflection layer, and a protective layer layer by layer on the substrate through an electron beam evaporation method;

[0037] (2) Annealing at 450 - 600 °C in a nitrogen atmosphere for 1 - 10 minutes to obtain the infrared selective radiation layer;

[0038] (3) Performing laser etching treatment on the infrared selective radiation layer;

[0039] (4) Fixing the etched infrared selective radiation layer and the microwave absorption layer to obtain the structure.

[0040] When performing the etching treatment, the etching thickness is greater than the total thickness of the film layer, being 1.2 - 2 μm, that is, ensuring that all layers above the substrate are etched. The laser power is generally 10 - 20 W (specifically, 15 W can be selected), and the pulse width is less than 15 ps, generally 5 - 15 ps. Through the laser etching pattern, it can be ensured that microwaves can penetrate the infrared selective radiation layer and be absorbed by the underlying microwave absorption layer.

[0041] The present invention can achieve compatible stealth in the short-wave infrared, mid-wave infrared, long-wave infrared bands, and microwave band at a high temperature of 700 °C, and the following conditions need to be met: at 700 °C, the short-wave infrared band of 1.4 - 2.5 μm, the mid-wave infrared band of 3 - 5 μm, and the long-wave infrared band of 8 - 14 μm have low emissivity to suppress the strong self-thermal radiation signal. In the X band of 8 - 12 GHz, it has high absorptivity to enhance the reflection loss of microwaves. In the non-atmospheric window of 5 - 8 μm, it has high emissivity to achieve efficient radiation scattering. The present invention can achieve low emissivity in the short-wave infrared, mid-wave infrared, and long-wave infrared bands and high absorptivity in the microwave band under high-temperature conditions, thus achieving the effect of infrared-microwave compatible stealth; at the same time, it realizes efficient radiation heat dissipation using the non-atmospheric window, and the preparation process is simple, which can meet the stealth requirements in multiple infrared bands and microwave bands under high-temperature environments and the thermal management requirements in high-temperature application scenarios such as aerospace.

[0042] The material with high temperature resistance, compatible with multi-infrared bands and microwave stealth, and efficient radiative heat dissipation of the present invention comprises a microwave absorption layer composed of a conductive ceramic backplane layer, a dielectric layer, and a periodic conductive ceramic patch layer, and an infrared selective radiation layer composed of a substrate, an adhesion layer, a metal reflection layer, a resonant cavity layer, an ultra-thin metal layer, a 5-8μm antireflection layer, and a protective layer. It satisfies that the short-wave infrared emissivity is less than 0.6 at 700°C, the emissivities of the mid-wave infrared and long-wave infrared are less than 0.5, the emissivity of 5-8μm is greater than 0.5, and the X-band reflection loss exceeds -3dB. The material structure of the present invention can achieve multi-infrared band and microwave stealth while having efficient radiative heat dissipation ability under high temperature conditions, and can be widely applied to high temperature scenarios in the fields of aviation, aerospace, etc.

[0043] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0044] The material with high temperature resistance, compatible with multi-infrared bands and microwave stealth, and efficient radiative heat dissipation of the present invention can significantly reduce the infrared radiation signals in the short-wave infrared, mid-wave infrared, and long-wave infrared bands and strongly suppress the microwave reflection echo under high temperature conditions, thereby greatly reducing the threat of the infrared microwave composite detection system. At the same time, the present invention realizes efficient radiative heat dissipation using non-atmospheric windows, has effective thermal management ability in high temperature environments, reduces the risk of performance degradation and structural damage of high-speed aircraft caused by high temperature, and can be widely applied to high temperature scenarios in the fields of aviation, aerospace, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a schematic structural diagram in Embodiment 1 of the present invention;

[0046] Figure 2 It is a physical diagram and microscope diagram of the sample in Embodiment 1 of the present invention;

[0047] Figure 3 It is a simulated and experimental absorption / emissivity spectrogram of the sample in Embodiment 1 of the present invention at room temperature;

[0048] Figure 4 It is an emissivity spectrogram of the sample in Embodiment 1 of the present invention from 200°C to 700°C;

[0049] Figure 5 It is an average emissivity diagram of the sample in Embodiment 1 of the present invention from room temperature to 700°C;

[0050] Figure 6 It is a microwave reflection loss diagram of the sample in Embodiment 1 of the present invention from room temperature to 700°C. DETAILED DESCRIPTION OF THE INVENTION

[0051] In order to make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below in conjunction with the specification drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0052] The following will describe the specific embodiments of the present invention in detail in conjunction with the specification drawings.

[0053] The present invention provides a material with high temperature resistance, compatible with multiple infrared bands and microwave stealth, and efficient radiation heat dissipation, including a microwave absorption layer composed of a conductive ceramic backplane layer 1, a dielectric layer 2, and a periodic conductive ceramic patch layer 3 arranged in sequence from inside to outside or from bottom to top, and an infrared selective radiation layer 4 composed of a substrate 401, an adhesion layer 402, a metal reflection layer 403, a resonant cavity layer 404, an ultra-thin metal layer 405, a 5-8μm antireflection layer 406, and a protective layer 407; the same substrate 401, adhesion layer 402, metal reflection layer 403, resonant cavity layer 404, ultra-thin metal layer 405, 5-8μm antireflection layer 406, and protective layer 407 are also arranged from bottom to top or from inside to outside; the bottom surface of the substrate 401 is in contact with the top surface of the periodic conductive ceramic patch layer 3.

[0054] The conductive ceramic backplane layer 1 is a high temperature resistant conductive ceramic material. Preferably, the material of the conductive ceramic backplane layer is titanium boride, and the thickness is greater than 0.5 mm.

[0055] The dielectric layer 2 is a high temperature resistant dielectric material. Preferably, the material of the dielectric layer is alumina, and the thickness is 0.5-5 mm.

[0056] The periodic conductive ceramic patch layer 3 is a high temperature resistant conductive ceramic material. Preferably, the periodic conductive ceramic patch layer is titanium boride. The period is 1-20 mm, the thickness is 0.2-1 mm, and the shape is geometric patterns such as square, rectangle, ring or a combination of multiple patterns. The above three layers function to absorb microwaves in the X band (8-12 GHz).

[0057] In actual production, the conductive ceramic backplane layer, the dielectric layer, and the periodic conductive ceramic patch layer are fixed by a high temperature resistant adhesive to form a microwave absorption layer; the high temperature resistant adhesive is an inorganic adhesive mainly composed of aluminosilicate. The substrate layer 401 is a high temperature resistant wave-transparent material, and further preferably alumina. The thickness selection of the substrate needs to consider the impedance matching of the overall structure, and is further preferably 1-10 mm.

[0058] The adhesion layer 402 is used to improve the adhesion between the multi-layer film and the substrate, generally metal titanium or chromium, further preferably titanium, and the thickness is 1-10 nm.

[0059] The metal reflective layer 403 is used to achieve low emissivity in short-wave infrared (1.4 - 2.5 μm), mid-wave infrared (3 - 5 μm), and long-wave infrared (8 - 14 μm), and absorb infrared light in the range of 5 - 8 μm. The material is a high-temperature resistant metal. Preferably, the material of the metal reflective layer is molybdenum, and the thickness is greater than 20 nm.

[0060] The resonant cavity layer 404 is used to achieve high emissivity in the non-atmospheric window (5 - 8 μm). The material is an infrared transparent and high-temperature resistant material. Preferably, the material of the resonant cavity layer is silicon, and the thickness is 200 - 1200 nm.

[0061] The ultra-thin metal layer 405 is used to achieve low emissivity in short-wave infrared (1.4 - 2.5 μm), mid-wave infrared (3 - 5 μm), and long-wave infrared (8 - 14 μm), and absorb infrared light in the range of 5 - 8 μm. The material is a high-temperature resistant metal. Preferably, the material of the ultra-thin metal layer is molybdenum, and the thickness is 1 - 20 nm.

[0062] The 5 - 8 μm antireflection layer 406 is used to enhance the absorption in the range of 5 - 8 μm. The material is an infrared transparent and high-temperature resistant material. Preferably, the material of the 5 - 8 μm antireflection layer is silicon, and the thickness is 200 - 1200 nm.

[0063] The protective layer 407 is used to prevent water vapor in the air from invading the multilayer film and damaging the film structure at high temperatures. Preferably, the material of the protective layer is alumina, and the thickness is 5 - 50 nm.

[0064] The infrared selective radiation layer is processed by an electron beam evaporation deposition process. That is, the adhesion layer, metal reflective layer, resonant cavity layer, ultra-thin metal layer, 5 - 8 μm antireflection layer, and protective layer are deposited layer by layer on the substrate layer by electron beam evaporation; after deposition, annealing treatment (annealing at 500 °C for 3 minutes in a nitrogen atmosphere) is performed to improve the quality of the multilayer film and obtain the main structure of the infrared selective radiation layer; after processing the main structure of the infrared selective radiation layer, laser etching treatment of the pattern is completed to finally obtain the infrared selective radiation layer structure;

[0065] The main structure of the infrared selective radiation layer needs to be subjected to laser etching treatment using a picosecond laser device (laser power is 15 W, pulse width is less than 15 ps). The etching period is 0.2 - 5 mm, the etching line width is 10 - 100 μm, and the pattern formed by etching is periodic horizontal and vertical lines.

[0066] The present invention is further described below in conjunction with specific embodiments.

[0067] Embodiments of the present invention are as follows:

[0068] Example 1

[0069] As Figure 1As shown in the figure, a material with high temperature resistance, compatible with multi-infrared bands, microwave stealth, and efficient radiative heat dissipation, includes a microwave absorption layer composed of a conductive ceramic backplane layer, a dielectric layer, and a periodic conductive ceramic patch layer arranged in sequence from inside to outside or from bottom to top, and an infrared selective radiation layer composed of a substrate, an adhesion layer, a metal reflection layer, a resonant cavity layer, an ultra-thin metal layer, a 5-8μm anti-reflection layer, and a protective layer;

[0070] Among them, for the conductive ceramic backplane layer material of the microwave absorption layer, a 1mm thick titanium boride layer is selected; for the dielectric layer material, a 1mm thick alumina layer is selected; for the periodic conductive ceramic patch layer, a square titanium boride patch with a period of 12mm, a thickness of 0.5mm, and a side length of 4.5mm is selected, and the above three are bonded and fixed with a aluminosilicate adhesive (model YK-8927).

[0071] For the substrate of the infrared selective radiation layer, a 2.3mm thick alumina layer is selected; for the adhesion layer, a 10nm thick titanium layer is selected; for the metal reflection layer, a 50nm thick molybdenum layer is selected; for the resonant cavity layer, a 700nm thick silicon layer is selected; for the ultra-thin metal layer, an 18nm thick molybdenum layer is selected; for the 5-8μm anti-reflection layer, a 390nm thick silicon layer is selected; for the protective layer, a 17nm thick alumina layer is selected. A picosecond laser is used to etch the multi-layer film, with an etching line width of 15μm and a period of 0.5mm. The physical diagram is as Figure 2 shown (the laser etching pattern is equidistant horizontal and vertical lines).

[0072] The absorption / emission rate spectrum of the above-mentioned material with high temperature resistance, compatible with multi-infrared bands, microwave stealth, and efficient radiative heat dissipation at room temperature is as Figure 3 shown. From Figure 3 it can be seen that the above multi-layer thin film realizes low emissivity stealth in the short-wave infrared, mid-wave infrared, and long-wave infrared bands, and at the same time realizes high emissivity heat dissipation in the 5-8μm band of the non-atmospheric window. Among them, in the 1.4-2.5μm short-wave infrared band, the average emissivity is 0.20; in the 3-5μm mid-wave infrared band, the average emissivity is 0.24. In the 8-14μm long-wave infrared band, the average emissivity is 0.16; in the 5-8μm very long-wave infrared band, the average emissivity is 0.67.

[0073] The emissivity spectrum of this embodiment at 200°C to 700°C is as Figure 4 and Figure 5 shown. As the temperature increases, the emissivity in the 3-14μm band increases slightly. At 700°C, the infrared light emissivity (or emissivity) in the 1.4-2.5μm band is lower than 0.6; at 700°C, the average emissivity in the mid-wave infrared band is 0.38, the average emissivity in the long-wave infrared band is 0.44, and the average emissivity in the 5-8μm band is 0.82. This shows that at high temperatures, this structure still has the effect of infrared stealth and stronger radiative heat dissipation ability.

[0074] The microwave reflection loss of this embodiment from room temperature to 700 °C is as Figure 6 shown. At room temperature, the reflection loss reaches -10 dB at 10.5 GHz. As the temperature increases, the microwave reflection loss decreases slightly, and the absorption peak frequency changes little. Even when the temperature reaches 700 °C, this structure can still maintain an effective absorption bandwidth from 9.6 GHz to 12 GHz, making the reflection loss exceed -3 dB, demonstrating its potential for high-temperature microwave stealth.

[0075] Those skilled in the art can easily understand that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high temperature resistant structure with multi-infrared band and microwave stealth functions, characterized in that: It includes a microwave absorption layer and an infrared selective radiation layer; the microwave absorption layer includes a conductive ceramic back plate layer, a dielectric layer and a periodic conductive ceramic patch layer arranged in sequence from the inside to the outside; the infrared selective radiation layer includes a substrate, an adhesion layer, a metal reflection layer, a resonant cavity layer, an ultra-thin metal layer, a 5-8μm anti-reflection layer, and a protective layer arranged in sequence from the inside to the outside.

2. The high temperature resistant structure with multi-infrared band and microwave stealth functions according to claim 1 is characterized in that: satisfy: The infrared radiation rate in the 1.4-2.5μm band is less than 0.6 at 700℃; The infrared light emissivity in the 3-5μm and 8-14μm bands is less than 0.5 at 700℃; The infrared light emissivity in the 5-8μm band is higher than 0.5 at 700℃; At 700℃, the microwave reflection loss in the 9.6-12GHz band exceeds -3dB.

3. The high temperature resistant structure with multi-infrared band and microwave stealth functions according to claim 1 is characterized in that: The materials of the conductive ceramic back plate layer and the periodic conductive ceramic patch layer are independently selected from one or more of zirconium boride, titanium boride, hafnium boride and titanium carbide.

4. The high temperature resistant structure with multi-infrared band and microwave stealth functions according to claim 1 is characterized in that: The dielectric layer material is one or more of aluminum oxide, silicon oxide, hafnium oxide, tantalum oxide, ytterbium silicate, sodium silicate and the like.

5. The high temperature resistant structure with multi-infrared band and microwave stealth functions according to claim 1 is characterized in that: The periodic conductive ceramic patch layer has a ceramic patch period of 1 to 20 mm, a thickness of 0.2 to 1.2 mm, and a shape that is a combination of one or more geometric patterns such as square, rectangle, and ring; the conductive ceramic backplane layer has a thickness greater than 0.5 mm; and the dielectric layer has a thickness of 0.5 to 5 mm.

6. The high temperature resistant structure with multi-infrared band and microwave stealth functions according to claim 1 is characterized in that: The material of the adhesion layer is metal titanium or chromium; the materials of the metal reflective layer and the ultra-thin metal layer are independently selected from one or more of high-temperature resistant metals such as platinum, iridium, palladium, tungsten, and molybdenum; the material of the resonant cavity layer and the material of the 5-8μm anti-reflection layer are independently selected from one or more of germanium, silicon, barium fluoride, calcium fluoride, magnesium fluoride, and zinc sulfide; the material of the protective layer is chromium oxide or aluminum oxide.

7. The high temperature resistant structure with multi-infrared band and microwave stealth functions according to claim 1 is characterized in that: The thickness of the adhesion layer is 1 to 10 nm; the thickness of the metal reflective layer is greater than 20 nm; the thickness of the resonant cavity layer is 200 to 1200 nm; the thickness of the ultra-thin metal layer is 1 to 25 nm; the thickness of the 5 to 8 μm anti-reflection layer is 200 to 1200 nm; and the thickness of the protective layer is 5 to 50 nm.

8. The high temperature resistant structure with multi-infrared band and microwave stealth functions according to claim 1 is characterized in that: The infrared selective radiation layer needs to be processed by laser etching, the etching period is 0.5-5 mm, the etching line width is 10-100 μm, and the etching pattern is a vertical and horizontal perpendicularly crossed line structure.

9. The high temperature resistant structure with multi-infrared band and microwave stealth functions according to claim 1, characterized in that: The conductive ceramic back plate layer is made of titanium boride with a thickness of 1 to 3 mm; the dielectric layer is made of aluminum oxide with a thickness of 0.8 to 4 mm; the periodic conductive ceramic patch layer is made of titanium boride with a period of 5 to 15 mm and a thickness of 0.4 to 0.8 mm; the adhesion layer is made of titanium with a thickness of 2 to 8 nm; the metal reflective layer is made of molybdenum with a thickness of 40 to 100 nm; the resonant cavity layer is made of silicon with a thickness of 400 to 800 nm; the ultra-thin metal layer is made of molybdenum with a thickness of 10 to 20 nm; the 5 to 8 μm anti-reflection layer is made of silicon with a thickness of 400 to 800 nm; the protective layer is made of aluminum oxide with a thickness of 10 to 40 nm; and the substrate material is made of aluminum oxide with a thickness of 1 to 5 mm.

10. A method for preparing a high temperature resistant structure having multiple infrared bands and microwave stealth functions as claimed in any one of claims 1 to 9, characterized in that: include: (1) depositing an adhesion layer, a metal reflection layer, a resonant cavity layer, an ultra-thin metal layer, a 5-8 μm anti-reflection layer and a protective layer layer by layer on the substrate by electron beam evaporation; (2) annealing at 450-600° C. in a nitrogen atmosphere for 1-10 minutes to obtain the infrared selective radiation layer; (3) performing laser etching on the infrared selective radiation layer; (4) Fixing the etched infrared selective radiation layer and the microwave absorption layer to obtain the structure.

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