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CN-121801465-B - Multifunctional protective coating for aerospace composite material thin-wall structure and preparation method thereof

CN121801465BCN 121801465 BCN121801465 BCN 121801465BCN-121801465-B

Abstract

The invention belongs to the technical field of surface protection and functional coating of aerospace fiber/polymer composite material thin-wall structures, and particularly relates to a multifunctional protective coating for an aerospace composite material thin-wall structure and a preparation method thereof. The coating sequentially comprises a polysilazane bonding layer, a polyimide-based vibration damping buffer layer, a ceramic protective layer and a ceramic protective layer, wherein the polysilazane bonding layer is used for enhancing interface bonding with a composite material matrix, the polyimide-based vibration damping buffer layer has heat buffering and vibration energy dissipation functions, the ceramic protective layer takes alumina and 8Y yttrium stabilized zirconia as main components and provides heat protection, wear resistance and erosion resistance, the multifunctional protective coating is prepared by adopting a wet spraying and medium-temperature staged curing process, high-temperature sintering equipment is not needed in the whole process, and the multifunctional protective coating is suitable for a composite material thin-wall structure. The invention solves the problem that the traditional single polymer or single ceramic coating is difficult to achieve both heat protection and vibration reduction performance.

Inventors

  • LI HUI
  • YANG YAO
  • Cao Jichuan
  • XU PEIYAO
  • WANG GUANJIN
  • ZHAI YUCHEN
  • SHI KEYAN
  • HAN QINGKAI
  • LI JINAN
  • SUN WEI
  • LIN ZENG
  • ZHAO FENG
  • MA HUI
  • LUO ZHONG
  • YANG BO
  • YAN HAILE

Assignees

  • 东北大学

Dates

Publication Date
20260512
Application Date
20260310

Claims (10)

  1. 1. The utility model provides a multi-functional protective coating for aerospace combined material thin wall structure which characterized in that, the coating includes from inside to outside in proper order: a polysilazane bonding layer for enhancing interfacial adhesion with the composite substrate; the polyimide-based vibration reduction buffer layer has the functions of heat buffering and vibration energy dissipation; the ceramic protective layer takes alumina and 8Y yttrium stabilized zirconia as main components and provides heat protection, wear resistance and erosion resistance; The multifunctional protective coating is deposited layer by adopting a wet spraying process, and is respectively and gradually heated and solidified within the range of 60-200 ℃ without high-temperature sintering equipment; And a polyimide-based capping layer is further arranged on the outer surface of the ceramic protective layer and used for improving surface flatness, color uniformity and additional wear resistance.
  2. 2. The multifunctional protective coating according to claim 1, wherein the polysilazane bonding layer is prepared from 15-30% polysilazane precursor, 15-35% n-methyl pyrrolidone solvent, 5-15% nano silica sol, 0.5-3% fumed silica, 40-65% xylene solvent and 0.1-0.5% defoamer by mass percent.
  3. 3. The multifunctional protective coating according to claim 1, wherein the polyimide-based vibration damping buffer layer is prepared from, by mass, 45% -65% of polyimide precursor solution, 5% -15% of alumina powder, 0.6% -5% of 8y yttrium-stabilized zirconia powder, 3% -10% of nano silica sol, 0.5% -2% of hydrophilic fumed silica, 15% -35% of n-methylpyrrolidone solvent, 0.2% -1.0% of dispersing agent and 0.1% -0.5% of defoaming agent, and optionally carbon nanotubes or graphene nanoplatelets as reinforcing filler, wherein the mass percentage of the reinforcing filler is 0.5% -0.8%.
  4. 4. The multifunctional protective coating according to claim 1, wherein the ceramic protective layer is prepared from, by mass, 20% -40% of alumina powder, 10% -15% of 8y yttrium-stabilized zirconia powder, 5% -15% of nano silica sol, 5% -20% of binder resin, 30% -40% of mixed solvent of absolute ethyl alcohol and N-methylpyrrolidone, 0.5% -2% of hydrophilic fumed silica, 0.2% -1.0% of dispersing agent and 0.1% -0.5% of defoaming agent, and the binder resin is polyvinyl butyral or polyimide precursor.
  5. 5. The multifunctional protective coating according to claim 1, wherein the polyimide-based capping layer has a thickness of 20 μm to 40 μm and is prepared from a low solid content polyimide precursor solution, fine alumina powder, 8Y yttrium stabilized zirconia powder, and nano-silica.
  6. 6. A method of producing a multifunctional protective coating according to any one of claims 1 to 5, comprising the steps of: step1, preprocessing the surface of a thin-wall structure of a composite material, including polishing, cleaning and drying; Step2, preparing polysilazane bonding layer paint, spraying the polysilazane bonding layer paint on the surface of the pretreated substrate, and curing the polysilazane bonding layer paint in stages to form a polysilazane bonding layer; Step 3, preparing polyimide-based vibration damping buffer layer paint, spraying the paint on the bonding layer, and curing the paint to form a polyimide-based vibration damping buffer layer; Step 4, preparing ceramic protective layer paint, spraying the ceramic protective layer paint on the vibration reduction buffer layer, and curing to form a ceramic protective layer; the spraying adopts a multi-pass thin spraying process, the standing time after each spraying pass is 20 minutes, and the solvent is volatilized after standing.
  7. 7. The method according to claim 6, wherein in the step 2, the polysilazane bonding layer coating is prepared by mixing a polysilazane precursor and a xylene solvent according to a certain mass ratio, adding nano silica sol and gas phase silica, stirring uniformly, and adding an antifoaming agent, wherein the curing process comprises the steps of firstly preserving heat at 80 ℃ for 30 minutes, then raising the temperature to 150 ℃ for 1 hour, and then raising the temperature to 200 ℃ for 1 hour.
  8. 8. The method according to claim 6, wherein in the step 3, the preparation of the polyimide-based vibration damping buffer layer coating comprises the steps of adding an N-methyl pyrrolidone solvent, a dispersing agent, nano silica sol, alumina powder and 8Y yttrium-stabilized zirconia powder into a polyimide precursor solution, and uniformly stirring, wherein the curing process comprises the steps of firstly carrying out heat preservation at 80 ℃ for 30 minutes, then carrying out heat preservation at 150 ℃ for 1 hour, and then carrying out heat preservation at 200 ℃ for 1 hour.
  9. 9. The method according to claim 6, wherein the preparation of the ceramic protective layer coating in the step 4 comprises mixing alumina powder and 8Y yttrium stabilized zirconia powder according to a predetermined mass ratio, adding a dispersing agent and nano silica sol, adding a mixed solvent of absolute ethyl alcohol and N-methylpyrrolidone and a binder resin, stirring uniformly, and adding hydrophilic fumed silica, wherein the curing process comprises the steps of firstly preserving heat at 80 ℃ for about 60 minutes, then raising the temperature to 150 ℃ for about 1 hour, and then raising the temperature to 200 ℃ for about 1 hour.
  10. 10. The method of claim 6, further comprising the step of preparing a capping layer coating and spraying it onto the surface of the ceramic blanket, and curing to form a capping layer.

Description

Multifunctional protective coating for aerospace composite material thin-wall structure and preparation method thereof Technical Field The invention belongs to the technical field of surface protection and functional coating of aerospace fiber/polymer composite material thin-wall structures, and particularly relates to a multifunctional protective coating for an aerospace composite material thin-wall structure and a preparation method thereof. Background At present, a large amount of fiber/polymer materials (comprising carbon fiber, aramid fiber, polyimide fiber, silicon carbide fiber and the like, epoxy resin, bismaleimide resin, polyether-ether-ketone resin, phenolic resin, polyimide resin and the like) are adopted in the aerospace thin-wall structure, and the composite thin-wall structure comprises aeroengine blades, a casing, a blisk, a spacecraft solar panel, a missile body fairing, a military transport aircraft wallboard, a warplane embedded bullet cabin wallboard, various aircraft skins and the like, and the composite thin-wall structure bears complex working conditions such as pneumatic heating, particle erosion, vibration, impact, thermal circulation and the like for a long time in the service process. On the one hand, the structural matrix generally employs fiber reinforced composite materials to reduce weight, but has limited resistance to high temperatures, abrasion and erosion. On the other hand, the local heat load is superposed with the mechanical load, so that damage and delamination are easily generated on the surface of the structure, and structural failure is caused when the damage and delamination are serious. Therefore, aiming at the thin-wall structure of the aerospace composite material, on the basis of facing the multifunctional protection requirement, the technical treatment of the coating surface is performed, and the method has become an important technical approach for improving the service life and the safety margin of the structure. In recent years, the surface coating technology has become an important means for improving the surface protection and mechanical property of the thin-wall structure of the fiber/polymer composite material. By coating the multifunctional coating on the surface of the thin-wall structure of the composite material, multiple protection functions such as heat collection protection, vibration reduction, shock resistance, corrosion resistance and the like can be integrated under the condition of not changing the structure size. Compared with the traditional coating, the advanced coating material integrating multiple functions can obviously improve the comprehensive performance of the component in a complex working environment, and can simultaneously cope with severe working conditions such as high temperature, vibration, impact, particle erosion and the like. However, most of the coating materials commonly used at present have the problem of single function, and it is difficult to satisfy various protection requirements. For example, common thermal protective coatings are primarily focused on thermal insulation, but lack vibration damping and impact resistance. The vibration damping coating can effectively inhibit vibration, but has a great performance deterioration in a high-temperature environment. The single-function coating material cannot effectively cope with the multi-field coupling effect faced by the aerospace structure, so that development of a novel coating with comprehensive protective performance is urgently needed to meet urgent requirements of modern aerospace equipment on high efficiency, multiple functions and long service life. Patent CN110791200A (application number: 2019110715817, application date: 2019, 11 month 5, public date: 2020, 2 month 14, patent name: a high temperature resistant coating for protecting polyimide composite material and a coating preparation method) discloses a high temperature resistant protective coating system for the surface of polyimide composite material, which can improve the heat resistant protection capability of the composite material in medium and high temperature environments. However, the patent mainly aims at the requirements of high temperature resistance and ablation resistance of the composite material, the overall design of the coating is still biased to a resin or resin modified system, and the abrasion resistance and the erosion resistance are insufficient. Meanwhile, the patent lacks special design and verification for common thermal-vibration coupling and thermal vibration fatigue working conditions of the aviation thin-wall structure in side weight thermal protection evaluation. Patent CN114411080A (application number: 2021116377046, application day: 2021, 11, 29, publication day 2022, 4, 29, patent name: a thermal protection composite coating and manufacturing method thereof) discloses a metal surface thermal protection coating structure and a manufacturing method thereof, and the thermal