Smart stealth material is a new type of stealth material. It is an organic combination of smart materials and stealth materials. It can sense the difference between the target and the background environment. Through the processing of the sensing signal, the material can adjust its own emissivity accordingly, reduce The radiation contrast between the small target and the environment enhances the target's adaptive ability. According to different inducing factors, smart stealth materials can be divided into electro-induced smart stealth materials and thermally induced smart stealth materials.
Electrochromic smart stealth materials are chemically changed in the composition of the material under the action of electric field or current, which in turn affects the infrared emissivity of the material. Conductive polymers and tungsten trioxide are widely researched and applied in electrovariable smart stealth materials. Chandrasekhar p studied the infrared emission performance of conductive polymer materials and found that its infrared reflectance in the range of 0.4~0.45m is adjustable from 0.3 to 0.7. Sauve K studied the changes of the infrared emissivity of tungsten trioxide (WO3) in the 3~5m and 8~12m bands. Through the control of the conductive factors, the change of the infrared emissivity of the WO3 film can reach 0.4.
The thermotropic material changes the infrared emissivity of the material by sensing the change in the surface temperature of the target. Bergeron BⅤ deposits copper on polyester film and cesium zinc to prepare a film material. The adjustment range is 0.51~0.83, and the change range of infrared emissivity in the 8~12m band is 0.20~0.73. Vanadium dioxide (VO2) is considered to be a kind of thermotropic smart stealth material with great application prospects. VO2 has six phases of R, M, B, A, C, and D. The change of temperature will cause the difference between the VO2 phases. Mutual transformation, along with its infrared transmittance and infrared emissivity will also have a certain change. Using hydrated vanadyl sulfate as the vanadium source, the M phase VO2, which has a reversible cycle with the R phase, is prepared by the second calcination, and the crystal phase change temperature is 62~67.9℃, the adjustable range of infrared emissivity in the 8-14m band is 0.12. WVO2 is prepared by doping modification of MZ by the second calcination method. WVO2 reaches the phase transition temperature at 48.2℃, and the infrared emissivity of the coating ranges from 0.752 to 0.95.
The emergence of intelligent stealth materials has promoted the development of infrared stealth materials. Through the intelligent adjustment of materials, the target can better adapt to the background environment and achieve better fusion effects with the background. However, the current smart stealth materials are still in the laboratory research stage and have not been widely used in practical applications.