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CN-122011940-A - Multifunctional stealth protective coating for aircraft surface and preparation process thereof

CN122011940ACN 122011940 ACN122011940 ACN 122011940ACN-122011940-A

Abstract

The invention discloses a multifunctional stealth protective coating for an aircraft surface and a preparation process thereof, and relates to the technical field of aviation coatings. The multifunctional stealth protective coating adopts the cooperative design of thermal response adjustment wave-absorbing powder and the modified organic silicon-epoxy hybrid resin matrix, can realize the self-adaptive regulation and control of a wave-absorbing structure in a high-temperature environment generated by high-speed flight of an aircraft, avoids the agglomeration of wave-absorbing fillers and the softening deformation of the resin matrix, keeps the stealth performance stable in the high-temperature environment, can ensure that the aircraft continuously responds to multiband cooperative detection in the dynamic flight process, effectively reduces the problem of stealth performance attenuation of the existing coating in the high-temperature environment, and ensures the stealth capability and task execution reliability of the aircraft.

Inventors

  • CAO JING
  • XIA QIXING
  • DONG WENQIANG

Assignees

  • 西北工业大学

Dates

Publication Date
20260512
Application Date
20260326

Claims (10)

  1. 1. The multifunctional stealth protective coating for the surface of the airplane is characterized by comprising a bottom adhesive force layer, a middle stealth layer and a bionic protective outer layer, wherein the multifunctional stealth protective coating comprises the following components in parts by weight: the bottom adhesive force layer comprises 45-55 parts of modified organosilicon-epoxy hybrid resin matrix, 2-4 parts of silane coupling agent KH-560, 1-3 parts of nano alumina powder, 0.5-1 part of dispersing agent BYK-163, 0.3-0.8 part of defoaming agent organosilicon emulsion and 15-20 parts of solvent butyl acetate; The middle stealth layer comprises 30-40 parts of modified organic silicon-epoxy hybrid resin matrix, 15-25 parts of core-shell structure composite functional filler, 8-12 parts of thermal response adjusting wave-absorbing powder, 5-8 parts of self-repairing agent, 2-5 parts of nano titanium nickel yellow, 0.3-0.6 part of flatting agent BYK-333 and 10-15 parts of solvent butyl acetate; The bionic protective outer layer comprises 50-60 parts of modified organosilicon-epoxy resin hybrid matrix, 3-6 parts of nano tungsten carbide powder, 2-4 parts of nano silicon dioxide powder, 0.5-1 part of ultraviolet absorber UV-531, 2-5 parts of temperature-humidity-sensitive composite powder, 0.5-1 part of fluorine modified acrylic ester auxiliary agent and 10-15 parts of butyl acetate solvent; the core of the core-shell structure composite functional filler is hollow alumina microsphere, the shell layer is sequentially provided with a nano silicon carbide-carbonyl iron powder composite wave absorbing layer and a nano silicon dioxide-polyaniline composite infrared low-emissivity layer from inside to outside, and the weight ratio of the core to the shell is 1:0.8-1.2.
  2. 2. The multifunctional stealth protective coating for the surface of an aircraft according to claim 1, wherein the thermal response adjustment wave-absorbing powder is prepared by compounding shape memory polyurethane microspheres and nano composite wave-absorbing powder according to a weight ratio of 2:1; The nano composite wave-absorbing powder is obtained by mixing nano silicon carbide powder, nano carbonyl iron powder and nano graphene powder according to a weight ratio of 3:3:1; The preparation method of the modified organosilicon-epoxy resin hybrid matrix comprises the following steps: Mixing bisphenol A type epoxy resin E-51 and hydroxyl end-capped polydimethylsiloxane resin according to a weight ratio of 2:1, adding 3-5% of silane coupling agent KH-560 by mass of bisphenol A type epoxy resin E-51, stirring and reacting for 2-3 hours at 60-70 ℃, and cooling to room temperature to obtain the modified organosilicon-epoxy resin hybrid matrix.
  3. 3. The multifunctional stealth protective coating for an aircraft surface according to claim 1, wherein the self-healing agent is a microcapsule of urea-formaldehyde resin coated bi-component epoxy healing agent, the particle size of the microcapsule is 5-10 μm, and the thickness of the shell wall is 0.5-1 μm; the bi-component epoxy repairing agent is prepared by mixing bisphenol A type epoxy resin E-44 and polyamide 650 curing agent according to the weight ratio of 1:1.
  4. 4. The multifunctional stealth protective coating for the surface of an aircraft according to claim 1, wherein the temperature-sensitive and humidity-sensitive composite powder is prepared by mixing temperature-sensitive powder and humidity-sensitive powder according to a weight ratio of 1:1; The temperature-sensitive powder is poly-N-isopropyl acrylamide grafted nano silicon dioxide powder, and the humidity-sensitive powder is montmorillonite-polyethylene glycol composite powder.
  5. 5. The multifunctional stealth protective coating for an aircraft surface according to claim 1, wherein the preparation method of the core-shell structure composite functional filler is specifically as follows: Placing the hollow alumina microspheres in a dilute hydrochloric acid solution with the volume fraction of 5% for ultrasonic cleaning for 10-15 min, flushing the hollow alumina microspheres to be neutral by deionized water, and drying the hollow alumina microspheres at the temperature of 80 ℃ for later use; dispersing the dried hollow alumina microspheres in an ethanol water mixed solution, adding mixed powder of nano silicon carbide powder and nano carbonyl iron powder, coating the surfaces of the microspheres by a sol-gel method to form a nano silicon carbide-carbonyl iron powder composite wave-absorbing layer, and drying to obtain microspheres of the wave-absorbing layer; Dispersing the wave absorbing layer microsphere in polyaniline water dispersion emulsion, adding nano silicon dioxide powder, coating for 30-40 min by ultrasonic, filtering, and drying at 100-120 ℃ to obtain the core-shell structure composite functional filler.
  6. 6. The multifunctional stealth protective coating for an aircraft surface according to claim 1, wherein the performance index of the multifunctional stealth protective coating is: The radar reflectivity is less than or equal to-15 dB in the frequency band of 2-18GHz, the reflectivity fluctuation is less than or equal to 2dB in the range of 0-60 degrees, the infrared emissivity is less than or equal to 0.3 in the wave band of 3-14 mu m, and the visible light camouflage color difference delta E is less than or equal to 1.0; The high-low temperature resistance is-80 ℃ to 300 ℃ and is circulated for 50 times without cracking and falling, the salt fog resistance is 5% sodium chloride solution salt fog test is 1500 hours without corrosion, when the self-repairing performance is that the scratch width is less than or equal to 50 mu m, the radar reflectivity of the repaired coating is recovered to more than 95% of the original performance, and the surface water contact angle is more than or equal to 120 degrees.
  7. 7. A process for the preparation of a multifunctional stealth protective coating for aircraft surfaces according to any one of claims 1 to 6, characterized in that it comprises the following steps: S1, sequentially polishing, degreasing and derusting an aircraft metal substrate to be sprayed, and then activating the surface of the aircraft metal substrate by adopting a low-temperature plasma surface treatment instrument, wherein the plasma power is 150-200W, the treatment time is 5-8 min, and the vacuum degree is 10-20 Pa; S2, uniformly mixing the modified organic silicon-epoxy hybrid resin matrix, the silane coupling agent KH-560, the nano alumina powder, the dispersing agent BYK-163, the defoamer organic silicon emulsion and the solvent butyl acetate, coating the mixture on the surface of the pretreated airplane metal substrate by adopting an air spraying method, controlling the thickness of a dry film to be 10-15 mu m, standing until the surface is dried, and forming the bottom adhesive layer; S3, after the spraying of the bottom adhesive force layer is finished, uniformly mixing the modified organic silicon-epoxy hybrid resin matrix, the core-shell structure composite functional filler, the thermal response adjustment wave-absorbing powder, the self-repairing agent, the nano titanium nickel yellow, the flatting agent BYK-333 and the solvent butyl acetate, coating the mixture on the surface of the surface-dried bottom adhesive force layer by adopting a high-pressure airless spraying method, controlling the dry film thickness to be 30-40 mu m, and standing until the surface is dry to form the middle stealth layer; S4, after the spraying of the middle stealth layer is finished, uniformly mixing the modified organic silicon-epoxy resin hybrid matrix, the nano tungsten carbide powder, the nano silicon dioxide powder, the ultraviolet absorbent UV-531, the temperature-humidity-sensitive composite powder, the fluorine modified acrylic ester auxiliary agent and the butyl acetate solvent, coating the mixture on the surface of the middle stealth layer after surface drying by adopting an electrostatic spraying method, controlling the thickness of a dry film to be 5-10 mu m, standing until the surface drying is finished, forming the bionic protection outer layer, and immediately adopting a template imprinting auxiliary solvent volatilization process for treatment after the spraying; S5, after the bottom adhesive force layer, the middle stealth layer and the bionic protection outer layer are sequentially sprayed, ultraviolet light with the wavelength of 365nm is firstly adopted to irradiate the surface of the coating, the illumination intensity is 800-1000mW/cm 2 , and the irradiation time is 5-10 min; s6, after ultraviolet irradiation is completed, placing the aircraft metal substrate coated with the coating in an electrothermal blowing drying oven, and carrying out sectional heating and solidification, wherein the temperature is kept at 40 ℃ for 1h, 60 ℃ for 1h and 80 ℃ for 2h, and naturally cooling to room temperature after solidification, so as to obtain the multifunctional stealth protective coating.
  8. 8. The process for preparing a multifunctional stealth protective coating for an aircraft surface according to claim 7, wherein in the steps S2, S3 and S4, the spraying pressure of the air spraying is 0.3-0.5MPa, the spraying pressure of the high-pressure airless spraying is 15-20MPa, and the voltage of the electrostatic spraying is 60-80kV.
  9. 9. The process for preparing the multifunctional stealth protective coating for the surface of the aircraft according to claim 7, wherein in the step S4, the template imprinting adopts a porous polytetrafluoroethylene template, the pore diameter of the template imprinting is 1-5 μm, the imprinting pressure is 0.1-0.2MPa, and the imprinting time is 1-2 min.
  10. 10. The process for preparing a multifunctional stealth protective coating for an aircraft surface according to claim 7, wherein in step S1, the surface roughness Ra of the aircraft metal substrate after polishing is controlled to be 1.6 μm; The oil removal treatment adopts acetone solvent for ultrasonic oil removal, and the ultrasonic time is 10min; the rust removal treatment adopts a phosphoric acid-based rust remover to carry out surface wiping treatment.

Description

Multifunctional stealth protective coating for aircraft surface and preparation process thereof Technical Field The invention relates to the technical field of aviation coating, in particular to a multifunctional stealth protective coating for an aircraft surface and a preparation process thereof. Background The stealth coating is a stealth material fixedly coated on the surface of an object, mainly comprises radar stealth, infrared stealth, visible light stealth, laser stealth, sonar stealth, multifunctional stealth coating and the like, reduces the probability of being found by a radar, infrared and other detection systems by coating the surface of an airplane, has the core function of absorbing or attenuating electromagnetic wave signals, thereby reducing the detectable characteristics of targets, and has the characteristics of wide-temperature chemical stability, low surface density, high adhesive strength and environmental change resistance. The existing full-band stealth coating of the aircraft adopts statically dispersed wave-absorbing fillers and a single-performance resin matrix, has no thermal response self-adaptive regulation and control capability, is easy to agglomerate in a 60-300 ℃ high-temperature environment generated by high-speed flight of the aircraft, and is easy to soften and deform to cause failure of a wave-absorbing structure, so that the radar reflectivity of the coating is obviously increased, the fluctuation of infrared emissivity is increased, the stealth performance is rapidly attenuated, multiband collaborative detection in a dynamic flight process can not be dealt with, and the battlefield viability and task execution reliability of the aircraft are seriously influenced. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a multifunctional stealth protective coating for the surface of an airplane and a preparation process thereof, and solves the problems mentioned in the background art. The multifunctional stealth protective coating for the aircraft surface is characterized by comprising a bottom adhesive layer, a middle stealth layer and a bionic protective outer layer, wherein the components in parts by weight are as follows: the bottom adhesive force layer comprises 45-55 parts of modified organosilicon-epoxy hybrid resin matrix, 2-4 parts of silane coupling agent KH-560, 1-3 parts of nano alumina powder, 0.5-1 part of dispersing agent BYK-163, 0.3-0.8 part of defoaming agent organosilicon emulsion and 15-20 parts of solvent butyl acetate; The middle stealth layer comprises 30-40 parts of modified organic silicon-epoxy hybrid resin matrix, 15-25 parts of core-shell structure composite functional filler, 8-12 parts of thermal response adjusting wave-absorbing powder, 5-8 parts of self-repairing agent, 2-5 parts of nano titanium nickel yellow, 0.3-0.6 part of flatting agent BYK-333 and 10-15 parts of solvent butyl acetate; The bionic protective outer layer comprises 50-60 parts of modified organosilicon-epoxy resin hybrid matrix, 3-6 parts of nano tungsten carbide powder, 2-4 parts of nano silicon dioxide powder, 0.5-1 part of ultraviolet absorber UV-531, 2-5 parts of temperature-humidity-sensitive composite powder, 0.5-1 part of fluorine modified acrylic ester auxiliary agent and 10-15 parts of butyl acetate solvent; the core of the core-shell structure composite functional filler is hollow alumina microsphere, the shell layer is sequentially provided with a nano silicon carbide-carbonyl iron powder composite wave absorbing layer and a nano silicon dioxide-polyaniline composite infrared low-emissivity layer from inside to outside, and the weight ratio of the core to the shell is 1:0.8-1.2. Preferably, the thermal response adjusting wave-absorbing powder is prepared by compounding shape memory polyurethane microspheres and nano composite wave-absorbing powder according to a weight ratio of 2:1; The nano composite wave-absorbing powder is obtained by mixing nano silicon carbide powder, nano carbonyl iron powder and nano graphene powder according to a weight ratio of 3:3:1; The preparation method of the modified organosilicon-epoxy resin hybrid matrix comprises the following steps: Mixing bisphenol A type epoxy resin E-51 and hydroxyl end-capped polydimethylsiloxane resin according to a weight ratio of 2:1, adding 3-5% of silane coupling agent KH-560 by mass of bisphenol A type epoxy resin E-51, stirring and reacting for 2-3 hours at 60-70 ℃, and cooling to room temperature to obtain the modified organosilicon-epoxy resin hybrid matrix. Preferably, the self-repairing agent is a microcapsule of urea resin coated bi-component epoxy repairing agent, the particle size of the microcapsule is 5-10 mu m, and the thickness of the shell wall is 0.5-1 mu m; the bi-component epoxy repairing agent is prepared by mixing bisphenol A type epoxy resin E-44 and polyamide 650 curing agent according to the weight ratio of 1:1. Preferably, the temperature-humidi