Broadband compatible multicolor camouflage composite film and preparation method thereof
By designing a wide-spectrum compatible multi-color camouflage composite film, and utilizing alternating high and low refractive index materials and electron beam evaporation, the problem of insufficient multi-band camouflage in existing technologies has been solved, achieving compatibility between multi-color camouflage and infrared camouflage, and meeting the camouflage requirements in complex environments.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HARBIN INST OF TECH
- Filing Date
- 2026-04-13
- Publication Date
- 2026-06-12
AI Technical Summary
Existing single-band camouflage technologies for visible light, mid-wave infrared, and long-wave infrared are insufficient to meet the requirements of multi-band synchronous camouflage in complex electromagnetic field environments and diverse combat scenarios, especially in terms of compatibility with visible light and infrared spectra.
A wide-spectrum compatible multicolor camouflage composite film was designed. The structure consists of a first dielectric material layer, a second metal layer, and alternating dielectric material layers from the inside out. It is prepared by selecting alternating high and low refractive index materials and electron beam evaporation to achieve camouflage effects for different wavelengths. The spectrum is controlled by the principle of multiple reflections and interference of light to achieve compatibility between multicolor camouflage and infrared camouflage.
It achieves infrared camouflage effects with low emissivity in the 3~5μm band, high emissivity in the 5~8μm band, and low emissivity in the 8~14μm band. It also has a variety of appearance colors, meeting the camouflage requirements of multi-band compatibility. The material cost is low and it is easy to mass-produce.
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Figure CN122192101A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of broadband stealth technology, and in particular to a broadband compatible multicolor camouflage composite film and its preparation method. Background Technology
[0002] The application of infrared detection and imaging devices in the military field has spurred the development of infrared detection and camouflage technologies. Camouflage technology aims to reduce the probability of detection by minimizing the signal difference between a target object and its background. Perfect camouflage typically involves mimicking the target in its surrounding environment, thus facilitating the evasion of human visual systems or modern detectors. In close-range combat, camouflaged targets often employ methods that minimize the color contrast between the target object and its background to evade enemy detection. In medium- and long-range operations, infrared camouflage technology plays a crucial role in countering infrared detectors (including thermal imaging systems and infrared-guided missiles) by matching the target's thermal radiation signal to the background.
[0003] With the continuous updating and improvement of detection technology, traditional single-band camouflage technologies such as visible light and mid-wave infrared (MWIR: 3~5μm) and long-wave infrared (LWIR: 8~14μm) are increasingly unable to meet the camouflage requirements of current military operations in complex electromagnetic field environments, diverse combat backgrounds, and various target shapes. Modern warfare has increasingly higher technical requirements for multi-band synchronous camouflage, especially the simultaneous compatibility with visible light and infrared spectra.
[0004] Therefore, there is an urgent need for a wide-spectrum compatible multicolor camouflage composite film and its preparation method. Summary of the Invention
[0005] This invention provides a wide-spectrum compatible multicolor camouflage composite film and its preparation method. The prepared multicolor camouflage composite film has the functions of both camouflage and infrared camouflage, improving its ability to detect various detection methods.
[0006] The present invention provides a broadband compatible multicolor camouflage composite film, comprising, from the inside out: a first dielectric material layer, a second metal layer, and alternating dielectric material layers arranged alternately with high and low refractive indices; the alternating dielectric material layers include at least five dielectric material layers; the first dielectric material layer has a refractive index greater than 4 in the infrared band; the second metal layer has a reflectivity greater than 80% in the infrared band; and the outermost dielectric material layer of the alternating dielectric material layers has a color corresponding to the peak reflection wavelength in the visible light band that is the same as the camouflage color.
[0007] Preferably, the first dielectric material layer is selected from Ge or PbTe.
[0008] Preferably, the second metal layer is selected from Ni, Al or Ag.
[0009] Preferably, the alternating dielectric material layer is selected from at least three of Ge, HfO2, SiO2, PbTe, Al2O3, MgO, or ZrO2.
[0010] Preferably, the outermost dielectric material layer of the alternating dielectric material layer is HfO2 or SiO2.
[0011] Preferably, the alternating dielectric material layers are a third, fourth, fifth, sixth, and seventh dielectric material layer arranged alternately in the order of refractive index decreasing first and then increasing; the fourth and sixth dielectric material layers are both selected from Ge or PbTe; the third and fifth dielectric material layers are both selected from one of HfO2, SiO2, Al2O3, MgO, or ZrO2; and the seventh dielectric material layer is HfO2.
[0012] Preferably, the alternating dielectric material layers are a third, fourth, fifth, sixth, seventh, and eighth dielectric material layer arranged alternately in the order of first high refractive index and then low refractive index; the third, fifth, and seventh dielectric material layers are all selected from Ge or PbTe; the fourth and sixth dielectric material layers are both selected from one of HfO2, SiO2, Al2O3, MgO, or ZrO2; and the eighth dielectric material layer is SiO2.
[0013] Preferably, the average emissivity of the multicolor camouflage composite film is less than 0.32 in the 3-5 μm band, not less than 0.73 in the 5-8 μm band, and less than 0.31 in the 8-14 μm band.
[0014] In a second aspect, the present invention provides a method for preparing the multicolor camouflage composite film of the first aspect above, comprising: The substrate was pretreated and then bombarded with an ion beam to obtain the initial substrate. The first dielectric material layer, the second metal layer, and the alternating dielectric material layers with alternating high and low refractive indices are sequentially deposited on the initial substrate using electron beam evaporation to obtain the multicolored camouflage composite film.
[0015] Preferably, the ion beam bombardment uses argon ions, with an ion beam current of 8~11A, a voltage of 120V, and a bombardment time of 9~12min.
[0016] Compared with the prior art, the present invention has at least the following beneficial effects: (1) This invention utilizes the wavelength differences of each detection band to design a layered structure, combining structures that meet the camouflage requirements of different bands to achieve multi-band compatible camouflage. The multicolor camouflage composite film of this invention consists of a first dielectric material layer, a second metal layer, and alternating dielectric material layers from the inside out, i.e., dielectric material layer-metal layer-dielectric material layer. The metal layer material is selected from Al, Ni, or Ag to provide high reflectivity in the infrared band. The dielectric material layer is selected from Ge, HfO2, SiO2, PbTe, Al2O3, Si, MgO, or ZrO2. Among them, the first dielectric material layer uses a high refractive index material to adjust the reflectivity of a specific band by controlling the phase of the transmitted light, thereby optimizing the overall design of the spectrum. The alternating dielectric material layer is a distributed Bragg reflector, which is composed of alternating stacks of high and low refractive index materials. It utilizes constructive interference to make a specific band have high reflectivity, thereby achieving fine control of the spectrum. Furthermore, by adjusting the thickness and material of the outermost dielectric layer of the alternating dielectric material layers, different apparent colors can be achieved using the principles of multiple reflections and interference of light, thus realizing the function of multi-color camouflage. In this way, the multi-color camouflage composite film designed in this invention achieves low emissivity of 3~5μm, high emissivity of 5~8μm, and low emissivity of 8~14μm, meeting the requirements of infrared camouflage. It also offers a variety of apparent colors, providing the effect of multi-color camouflage, and even achieving low absorption in the solar band under certain conditions, successfully realizing the design goal of wide-spectrum compatible multi-color camouflage.
[0017] (2) The materials used in the preparation of the multicolor camouflage composite film of the present invention have low production costs, are easy to store, and pose no safety hazards. Moreover, the preparation process is simple, easy to operate, and suitable for mass production. Attached Figure Description
[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0019] Figure 1 This is a schematic diagram of the structure of a wide-spectrum compatible multicolor camouflage composite film provided in an embodiment of the present invention; Figure 2 These are the spectral reflectance curves of four colorful camouflage composite films provided in one embodiment of the present invention; Figure 3 These are the spectral reflectance curves of two colorful camouflage composite films provided in an embodiment of the present invention; Reference numerals: 10 - first dielectric material layer, 20 - second metal layer, 30 - alternating dielectric material layer. Detailed Implementation
[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0021] The following is the concept of the present invention, which provides a wide-spectrum compatible multicolor camouflage composite film, such as... Figure 1 As shown, from the inside out, it includes: a first dielectric material layer 10, a second metal layer 20, and alternating dielectric material layers 30 arranged with alternating refractive indices; the alternating dielectric material layers 30 include at least five dielectric material layers; the first dielectric material layer 10 has a refractive index greater than 4 in the infrared band; the second metal layer 20 has a reflectivity greater than 80% in the infrared band; the outermost dielectric material layer of the alternating dielectric material layers 30 has a color corresponding to the peak wavelength of reflection in the visible light band that is the same as the camouflage color.
[0022] It should be noted that the first dielectric material layer is adjacent to the substrate and is a single-layer film, thus ensuring the adhesion between the multicolor camouflage composite film and the substrate, further ensuring the stability of the multicolor camouflage composite film. The outer surface of the outermost dielectric material layer of the alternating dielectric layers. The materials of adjacent layers in the multicolor camouflage composite film are different.
[0023] In this embodiment of the invention, the multicolor camouflage composite film comprises, from the inside out: a first dielectric material layer, a second metal layer, and alternating dielectric material layers. The first dielectric material layer is in contact with the substrate and is made of a high refractive index material with a refractive index greater than 4. This material is used to adjust the reflectivity of specific wavelengths by controlling the phase of transmitted light, thereby optimizing the overall spectral design. The metal layer is made of a metal material with a reflectivity greater than 80% in the infrared band to provide high reflectivity in the infrared band. Then, through the alternating dielectric material layers composed of alternating stacks of high and low refractive index materials (or low and high refractive index materials), constructive interference is used to achieve high reflectivity in specific wavelengths, thereby realizing fine-tuning of the spectrum. Simultaneously, by adjusting the thickness and material selection of each layer in the outermost dielectric material layer, different apparent colors are achieved using the principles of multiple reflections and interference of light, thus realizing the function of multicolor camouflage.
[0024] In some preferred embodiments, the first dielectric material layer is selected from Ge or PbTe.
[0025] In some preferred embodiments, the second metal layer is selected from Ni, Al, or Ag.
[0026] In some preferred embodiments, the alternating dielectric material layers are selected from at least three of Ge, HfO2, SiO2, PbTe, Al2O3, MgO, or ZrO2.
[0027] In some preferred embodiments, the outermost dielectric material layer of the alternating dielectric material layers is HfO2 or SiO2.
[0028] In this invention, by adjusting the thickness of the outermost dielectric material layer and utilizing the principles of multiple interference and reflection of light, the multicolored camouflage composite film can exhibit a variety of different single colors, thereby better concealing itself in the environment.
[0029] In this invention, the alternating dielectric material layers are arranged according to their refractive indices, with two arrangement rules. The first rule is to stack materials with alternating low and high refractive indices, i.e., high refractive index-low refractive index-high refractive index-low refractive index-...; the second rule is to stack materials with alternating high and low refractive indices, i.e., low refractive index-high refractive index-low refractive index-high refractive index-.... This alternating design with different refractive indices optimizes the spectral design and protects the easily oxidized thin metal layer.
[0030] It should be noted that the alternating dielectric material layers in this invention do not possess strict periodicity; they are simply composed of different high-refractive-index and low-refractive-index materials stacked alternately, with varying thicknesses for each layer. Furthermore, these alternating dielectric material layers not only achieve infrared stealth capabilities but also, under certain conditions, exhibit low absorption in the solar band, thereby reducing the solar radiation absorptivity and minimizing surface temperature rise. In addition, the low absorption function in the solar band, combined with the high-emission radiative heat dissipation of the multicolored camouflage composite film in the 5-8 μm wavelength range, enables effective thermal management of the entire film system.
[0031] In some preferred embodiments, for the first alternating arrangement: the alternating dielectric material layers are a third dielectric material layer, a fourth dielectric material layer, a fifth dielectric material layer, a sixth dielectric material layer, and a seventh dielectric material layer arranged in an alternating order of refractive index first low and then high; the fourth and sixth dielectric material layers are both selected from Ge or PbTe; the third and fifth dielectric material layers are both selected from one of HfO2, SiO2, Al2O3, MgO, or ZrO2; and the seventh dielectric material layer is HfO2.
[0032] In some preferred embodiments, when the camouflage color is green, the first dielectric layer is Ge with a thickness of 310 nm, the second metal layer is Al with a thickness of 7 nm, the third dielectric layer is MgO with a thickness of 46 nm, the fourth dielectric layer is PbTe with a thickness of 150 nm, the fifth dielectric layer is Al2O3 with a thickness of 85 nm, the sixth dielectric layer is Ge with a thickness of 80 nm, and the seventh dielectric layer is HfO2 with a thickness of 240 nm.
[0033] In some preferred embodiments, when the camouflage color is orange, the first dielectric layer is Ge with a thickness of 320 nm, the second metal layer is Ag with a thickness of 7.2 nm, the third dielectric layer is HfO2 with a thickness of 100 nm, the fourth dielectric layer is Ge with a thickness of 140 nm, the fifth dielectric layer is ZrO2 with a thickness of 70 nm, the sixth dielectric layer is Ge with a thickness of 90 nm, and the seventh dielectric layer is HfO2 with a thickness of 50 nm.
[0034] In some preferred embodiments, when the camouflage color is purple, the first dielectric material layer is PbTe with a thickness of 320 nm, the second metal layer is Ni with a thickness of 30 nm, the third dielectric material layer is HfO2 with a thickness of 110 nm, the fourth dielectric material layer is PbTe with a thickness of 150 nm, the fifth dielectric material layer is HfO2 with a thickness of 70 nm, the sixth dielectric material layer is Ge with a thickness of 80 nm, and the seventh dielectric material layer is HfO2 with a thickness of 65 nm.
[0035] In some preferred embodiments, when the camouflage color is blue, the first dielectric material layer is Ge with a thickness of 320 nm, the second metal layer is Ag with a thickness of 7.2 nm, the third dielectric material layer is Al2O3 with a thickness of 100 nm, the fourth dielectric material layer is Ge with a thickness of 110 nm, the fifth dielectric material layer is SiO2 with a thickness of 95 nm, the sixth dielectric material layer is Ge with a thickness of 110 nm, and the seventh dielectric material layer is HfO2 with a thickness of 70 nm.
[0036] In this invention, the multicolor camouflage composite film obtained by the first alternating arrangement has both multicolor camouflage and infrared camouflage functions.
[0037] In some preferred embodiments, for the second alternating arrangement: the alternating dielectric material layers are a third, fourth, fifth, sixth, seventh, and eighth dielectric material layer arranged in an alternating order of first high and then low refractive index; the third, fifth, and seventh dielectric material layers are all selected from Ge or PbTe; the fourth and sixth dielectric material layers are both selected from one of HfO2, SiO2, Al2O3, MgO, or ZrO2; and the eighth dielectric material layer is SiO2.
[0038] In some preferred embodiments, when the camouflage color is light yellow, the first dielectric material layer is Ge with a thickness of 320 nm, the second metal layer is Ag with a thickness of 7.7 nm, the third dielectric material layer is Ge with a thickness of 300 nm, the fourth dielectric material layer is SiO2 with a thickness of 68 nm, the fifth dielectric material layer is Ge with a thickness of 35 nm, the sixth dielectric material layer is SiO2 with a thickness of 123 nm, the seventh dielectric material layer is Ge with a thickness of 20 nm, and the eighth dielectric material layer is SiO2 with a thickness of 10 nm.
[0039] In some preferred embodiments, when the camouflage color is pink, the first dielectric layer is Ge with a thickness of 320 nm, the second metal layer is Ag with a thickness of 7.7 nm, the third dielectric layer is Ge with a thickness of 300 nm, the fourth dielectric layer is SiO2 with a thickness of 68 nm, the fifth dielectric layer is Ge with a thickness of 35 nm, the sixth dielectric layer is HfO2 with a thickness of 138 nm, the seventh dielectric layer is Ge with a thickness of 20 nm, and the eighth dielectric layer is SiO2 with a thickness of 10 nm.
[0040] In this invention, the multicolor camouflage composite film obtained by the second alternating arrangement has the functions of multicolor camouflage, infrared camouflage and low absorption rate in the solar band.
[0041] In some preferred embodiments, the average emissivity of the multicolor camouflage composite film is less than 0.32 in the 3-5 μm band, not less than 0.73 in the 5-8 μm band, and less than 0.31 in the 8-14 μm band.
[0042] This invention also provides a method for preparing a multicolored camouflage composite film, comprising: The substrate was pretreated and then bombarded with an ion beam to obtain the initial substrate. A multicolored camouflage composite film was obtained by sequentially depositing a first dielectric material layer, a second metal layer, and alternating dielectric material layers arranged according to refractive indices on an initial substrate using electron beam evaporation.
[0043] Specifically, the substrate can be either a rigid substrate or an organic flexible substrate, and the substrate surface needs to be kept clean. Therefore, pretreatment includes, but is not limited to, purging with argon gas. If the substrate is rigid, it can be cleaned and then purged with argon gas to ensure that the substrate surface is free of dust.
[0044] In some preferred embodiments, the ion beam bombardment uses argon ions, the ion beam current is 8~11A (e.g., 8A, 9A, 10A or 11A), the voltage is 120V, and the bombardment time is 10~12min (e.g., 9min, 10min, 11min or 12min).
[0045] In this invention, the adhesion of the film layer is increased by bombardment with an ion beam.
[0046] Unless otherwise specified, the raw materials used in this invention can be products that are readily available on the market.
[0047] The present invention will be further described below by way of examples, but the scope of protection of the present invention is not limited to these embodiments.
[0048] Example 1 A wide-spectrum compatible multicolor camouflage composite film comprises, from the inside out: a first dielectric material layer of Ge with a thickness of 310 nm, a second metal layer of Al with a thickness of 7 nm, a third dielectric material layer of MgO with a thickness of 46 nm, a fourth dielectric material layer of PbTe with a thickness of 150 nm, a fifth dielectric material layer of Al2O3 with a thickness of 85 nm, a sixth dielectric material layer of Ge with a thickness of 80 nm, and a seventh dielectric material layer of HfO2 with a thickness of 240 nm; the camouflage color of the composite film is green.
[0049] The preparation method of the above-mentioned multicolor camouflage composite film includes: (1) The surface of the polyimide substrate is purged with argon gas to ensure that the surface is clean; then the cleaned substrate is bombarded with argon ions at room temperature (e.g., 25°C) with an ion beam current of 8A, a voltage of 120V and a bombardment time of 12min to obtain the initial substrate. (2) According to the above material layup order and thickness, Ge, Al, MgO, PbTe, Al2O3, Ge and HfO2 are deposited sequentially on the initial substrate obtained in step (1) by electron beam evaporation to obtain a multicolored camouflage composite film.
[0050] The composite film prepared in this embodiment has an apparent color of green, an average emissivity of 0.312 in the 3-5 μm band, an average emissivity of 0.794 in the 5-8 μm band, and an average emissivity of 0.309 in the 8-14 μm band. Its spectral reflectance curve is shown below. Figure 2 As shown by the green curve in the figure, the low emissivity of this composite film at 3–5 μm and 8–14 μm provides excellent infrared camouflage performance, while the high emissivity at 5–8 μm offers good radiative cooling, ensuring the stability of its infrared camouflage function. This composite film can be applied to camouflage in forests and grasslands.
[0051] Example 2 A wide-spectrum compatible multicolor camouflage composite film comprises, from the inside out: a first dielectric material layer of Ge with a thickness of 320 nm, a second metal layer of Ag with a thickness of 7.2 nm, a third dielectric material layer of HfO2 with a thickness of 100 nm, a fourth dielectric material layer of Ge with a thickness of 140 nm, a fifth dielectric material layer of ZrO2 with a thickness of 70 nm, a sixth dielectric material layer of Ge with a thickness of 90 nm, and a seventh dielectric material layer of HfO2 with a thickness of 50 nm; the camouflage color of the composite film is orange.
[0052] The preparation method of the above-mentioned multicolor camouflage composite film includes: (1) The surface of the polyimide substrate was purged with argon gas to ensure that the surface was clean; then the cleaned substrate was bombarded with argon ions at room temperature (e.g., 25°C) with an ion beam current of 9A, a voltage of 120V and a bombardment time of 11min to obtain the initial substrate. (2) According to the above material layup order and thickness, Ge, Ag, HfO2, Ge, ZrO2, Ge and HfO2 are deposited sequentially on the initial substrate obtained in step (1) by electron beam evaporation to obtain a multicolor camouflage composite film.
[0053] The composite film prepared in this embodiment has an apparent color of orange, with an average emissivity of 0.167 in the 3-5 μm band, 0.756 in the 5-8 μm band, and 0.24 in the 8-14 μm band. Its spectral reflectance curve is shown below. Figure 2 As shown by the orange curve, the low emissivity of this composite film at 3–5 μm and 8–14 μm provides excellent infrared camouflage performance, while the high emissivity at 5–8 μm offers good radiative cooling, ensuring the stability of its infrared camouflage function. This composite film can be applied to camouflage in deserts and Gobi.
[0054] Example 3 A wide-spectrum compatible multicolor camouflage composite film comprises, from the inside out: a first dielectric material layer of PbTe with a thickness of 320 nm, a second metal layer of Ni with a thickness of 30 nm, a third dielectric material layer of HfO2 with a thickness of 110 nm, a fourth dielectric material layer of PbTe with a thickness of 150 nm, a fifth dielectric material layer of HfO2 with a thickness of 70 nm, a sixth dielectric material layer of Ge with a thickness of 80 nm, and a seventh dielectric material layer of HfO2 with a thickness of 65 nm; the camouflage color of the composite film is purple.
[0055] The preparation method of the above-mentioned multicolor camouflage composite film includes: (1) The surface of the polyimide substrate is purged with argon gas to ensure that the surface is clean; then the cleaned substrate is bombarded with argon ions at room temperature (e.g., 25°C) with an ion beam current of 10A, a voltage of 120V and a bombardment time of 10min to obtain the initial substrate. (2) According to the above material layup order and thickness, PbTe, Ni, HfO2, PbTe, HfO2, Ge and HfO2 are sequentially deposited on the initial substrate obtained in step (1) according to the above thickness and order to obtain a multicolor camouflage composite film.
[0056] The composite film prepared in this embodiment has a purple appearance. Its average emissivity is 0.167 in the 3–5 μm wavelength range, 0.756 in the 5–8 μm wavelength range, and 0.24 in the 8–14 μm wavelength range. Its spectral reflectance curve is shown below. Figure 2 As shown by the purple curve, the low emissivity of this composite film at 3–5 μm and 8–14 μm provides excellent infrared camouflage performance, while the high emissivity at 5–8 μm offers good radiative cooling, ensuring the stability of its infrared camouflage function. This composite film can be applied to meet specific color requirements for camouflage of certain targets.
[0057] Example 4 A wide-spectrum compatible multicolor camouflage composite film comprises, from the inside out: a first dielectric material layer of Ge with a thickness of 320 nm, a second metal layer of Ag with a thickness of 7.2 nm, a third dielectric material layer of Al2O3 with a thickness of 100 nm, a fourth dielectric material layer of Ge with a thickness of 110 nm, a fifth dielectric material layer of SiO2 with a thickness of 95 nm, a sixth dielectric material layer of Ge with a thickness of 110 nm, and a seventh dielectric material layer of HfO2 with a thickness of 70 nm; the camouflage color of the composite film is blue.
[0058] The preparation method of the above-mentioned multicolor camouflage composite film includes: (1) The surface of the polyimide substrate is purged with argon gas to ensure that the surface is clean; then the cleaned substrate is bombarded with argon ions at room temperature (e.g., 25°C) with an ion beam current of 11A, a voltage of 120V and a bombardment time of 9min to obtain the initial substrate. (2) According to the above material layup order and thickness, Ge, Ag, Al2O3, Ge, SiO2, Ge and HfO2 are deposited sequentially on the initial substrate obtained in step (1) by electron beam evaporation to obtain a multicolored camouflage composite film.
[0059] The composite film prepared in this embodiment has an apparent color of blue, an average emissivity of 0.186 in the 3-5 μm band, an average emissivity of 0.723 in the 5-8 μm band, and an average emissivity of 0.305 in the 8-14 μm band. Its spectral reflectance curve is shown below. Figure 2 As shown by the blue curve, the low emissivity of this composite film at 3–5 μm and 8–14 μm provides excellent infrared camouflage performance, while the high emissivity at 5–8 μm offers good radiative cooling, ensuring the stability of its infrared camouflage function. This composite film can be applied to camouflage in oceans and lakes.
[0060] Example 5 A wide-spectrum compatible multicolor camouflage composite film comprises, from the inside out: a first dielectric material layer of Ge with a thickness of 320 nm, a second metal layer of Ag with a thickness of 7.7 nm, a third dielectric material layer of Ge with a thickness of 300 nm, a fourth dielectric material layer of SiO2 with a thickness of 68 nm, a fifth dielectric material layer of Ge with a thickness of 35 nm, a sixth dielectric material layer of SiO2 with a thickness of 123 nm, a seventh dielectric material layer of Ge with a thickness of 20 nm, and an eighth dielectric material layer of SiO2 with a thickness of 10 nm; the camouflage color of the composite film is light yellow.
[0061] The preparation method of the above-mentioned multicolor camouflage composite film includes: (1) The surface of the polyimide substrate is purged with argon gas to ensure that the surface is clean; then the cleaned substrate is bombarded with argon ions at room temperature (e.g., 25°C) with an ion beam current of 8A, a voltage of 120V and a bombardment time of 12min to obtain the initial substrate. (2) According to the above material layup order and thickness, Ge, Ag, Ge, SiO2, Ge, SiO2, Ge, SiO2, Ge, SiO2 are deposited sequentially on the initial substrate obtained in step (1) by electron beam evaporation to obtain a multicolor camouflage composite film.
[0062] The composite film prepared in this embodiment has a pale yellow appearance. Its absorptivity is 0.425 in the solar band (0.25–2.5 μm), its average emissivity is 0.226 in the 3–5 μm band, 0.765 in the 5–8 μm band, and 0.343 in the 8–14 μm band. Its spectral reflectance curve is shown below. Figure 3 The light yellow curve indicates that the low emissivity of this composite film at 3–5 μm and 8–14 μm provides excellent infrared camouflage performance, while the high emissivity at 5–8 μm and low solar absorptivity offer good radiative cooling, allowing the composite film to maintain a stable temperature over a long period and improving the stability of its infrared camouflage function. This composite film can be applied to meet the camouflage requirements of deserts and Gobi regions.
[0063] Example 6 A wide-spectrum compatible multicolor camouflage composite film comprises, from the inside out: a first dielectric material layer of Ge with a thickness of 320 nm, a second metal layer of Ag with a thickness of 7.7 nm, a third dielectric material layer of Ge with a thickness of 300 nm, a fourth dielectric material layer of SiO2 with a thickness of 68 nm, a fifth dielectric material layer of Ge with a thickness of 35 nm, a sixth dielectric material layer of HfO2 with a thickness of 138 nm, a seventh dielectric material layer of Ge with a thickness of 20 nm, and an eighth dielectric material layer of SiO2 with a thickness of 10 nm; the camouflage color of the composite film is pink.
[0064] The preparation method of the above-mentioned multicolor camouflage composite film includes: (1) The surface of the polyimide substrate is purged with argon gas to ensure that the surface is clean; then the cleaned substrate is bombarded with argon ions at room temperature (e.g., 25°C) with an ion beam current of 8A, a voltage of 120V and a bombardment time of 12min to obtain the initial substrate. (2) According to the above material layup order and thickness, Ge, Ag, Ge, SiO2, Ge, HfO2, Ge, SiO2 are deposited sequentially on the initial substrate obtained in step (1) by electron beam evaporation to obtain a multicolor camouflage composite film.
[0065] The composite film prepared in this embodiment has a pink appearance. Its absorptivity is 0.435 in the solar band (0.25–2.5 μm), its average emissivity is 0.229 in the 3–5 μm band, 0.731 in the 5–8 μm band, and 0.33 in the 8–14 μm band. Its spectral reflectance curve is shown below. Figure 3As shown by the pink curve in the image, the low emissivity of this composite film at 3–5 μm and 8–14 μm provides excellent infrared camouflage performance, while the high emissivity and low solar absorptivity at 5–8 μm offer good radiative cooling, allowing the composite film to maintain a stable temperature over a long period and improving the stability of its infrared camouflage function. This composite film can be applied to meet the specific color requirements of certain targets.
[0066] It should be noted that the average emissivity can be calculated from the spectral reflectance curve.
[0067] The parts of this invention not described in detail are techniques known to those skilled in the art.
[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A broadband compatible multicolor camouflage composite film, characterized in that, From the inside out, it includes: a first dielectric material layer, a second metal layer, and alternating dielectric material layers arranged with alternating high and low refractive indices; the alternating dielectric material layers include at least five dielectric material layers; the first dielectric material layer has a refractive index greater than 4 in the infrared band; the second metal layer has a reflectivity greater than 80% in the infrared band; the outermost dielectric material layer of the alternating dielectric material layers has a color corresponding to the peak wavelength of reflection in the visible light band that is the same as the camouflage color.
2. The multicolored camouflage composite film according to claim 1, characterized in that, The first dielectric material layer is selected from Ge or PbTe.
3. The multicolored camouflage composite film according to claim 1, characterized in that, The second metal layer is selected from Ni, Al or Ag.
4. The multicolored camouflage composite film according to claim 1, characterized in that, The alternating dielectric material layer is selected from at least three of Ge, HfO2, SiO2, PbTe, Al2O3, MgO, or ZrO2.
5. The multicolored camouflage composite film according to claim 1, characterized in that, The outermost dielectric material layer of the alternating dielectric material layer is HfO2 or SiO2.
6. The multicolored camouflage composite film according to claim 1, characterized in that, The alternating dielectric material layers are a third, fourth, fifth, sixth, and seventh dielectric material layer arranged in an alternating order of refractive index decreasing first and then increasing; the fourth and sixth dielectric material layers are both selected from Ge or PbTe; the third and fifth dielectric material layers are both selected from one of HfO2, SiO2, Al2O3, MgO, or ZrO2; the seventh dielectric material layer is HfO2.
7. The multicolored camouflage composite film according to claim 1, characterized in that, The alternating dielectric material layers are arranged in an alternating order of refractive index, namely, the third, fourth, fifth, sixth, seventh, and eighth dielectric material layers; the third, fifth, and seventh dielectric material layers are all selected from Ge or PbTe; the fourth and sixth dielectric material layers are both selected from one of HfO2, SiO2, Al2O3, MgO, or ZrO2; and the eighth dielectric material layer is SiO2.
8. A multi-colored camouflage composite film as described in any one of claims 1 to 7, characterized in that: The average emissivity is less than 0.32 in the 3-5 μm band, not less than 0.73 in the 5-8 μm band, and less than 0.31 in the 8-14 μm band.
9. A method for preparing a multicolored camouflage composite film as described in any one of claims 1 to 8, characterized in that, include: The substrate was pretreated and then bombarded with an ion beam to obtain the initial substrate. The first dielectric material layer, the second metal layer, and the alternating dielectric material layers with alternating high and low refractive indices are sequentially deposited on the initial substrate using electron beam evaporation to obtain the multicolored camouflage composite film.
10. The preparation method according to claim 9, characterized in that, The ion beam bombardment uses argon ions, with an ion beam current of 8~11A, a voltage of 120V, and a bombardment time of 9~12min.