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CN-122011501-A - Aramid fiber wave-absorbing honeycomb with microcosmic sandwich hole wall structure and in-situ manufacturing method thereof

CN122011501ACN 122011501 ACN122011501 ACN 122011501ACN-122011501-A

Abstract

The invention relates to the technical field of honeycomb composite materials, in particular to an aramid fiber wave-absorbing honeycomb with a microscopic sandwich hole wall structure and an in-situ manufacturing method thereof, which comprises the steps of step 1, preparation of an aramid fiber honeycomb blank, step 2, first-order impregnation, step 3, second-order impregnation, step 4, third-order impregnation, step 5, high-temperature stepped curing and cross-layer co-curing, and finally forming the microscopic sandwich hole wall structure formed by a pure resin substrate layer, a wave-absorbing functional layer and a pure resin cover layer which are distributed in sequence along the thickness direction of the honeycomb hole wall. According to the invention, through three-order alternate impregnation, a microstructure sandwich structure consisting of the pure resin substrate layer, the wave-absorbing functional layer and the pure resin sealing layer is constructed in the honeycomb hole wall, so that the mechanical enhancement of the hole wall, the wave-absorbing functional introduction and the wave-absorbing particle encapsulation stability are taken into consideration.

Inventors

  • Yue Dianhui
  • GUO JIA
  • ZHAO ZIYE
  • WEI PENG
  • LIU RONG
  • DAI JIAMU
  • ZHANG WEI

Assignees

  • 南通大学

Dates

Publication Date
20260512
Application Date
20260323

Claims (10)

  1. 1. An in-situ manufacturing method of an aramid fiber wave-absorbing honeycomb with a microcosmic sandwich hole wall structure is characterized by comprising the following steps: Step 1, preparation of aramid honeycomb blank Coating node glue on the surface of aramid paper according to a preset stripe width, and stretching and shaping along the direction perpendicular to the stripe of the node glue after superposition, hot pressing and solidification to obtain an aramid honeycomb blank which is not impregnated with structural resin; Step2, first order impregnation Immersing the aramid fiber honeycomb blank obtained in the step 1 into a first resin liquid for 1-3 minutes, blowing out redundant glue solution in holes by adopting compressed air of 0.1-0.2 MPa after the step is proposed, and then performing primary heat treatment at 70-90 ℃ to enable the resin to reach a shallow gel state, and forming a pure resin substrate layer on the surface of the aramid fiber in situ; Step 3, second-stage impregnation Immersing the aramid fiber honeycomb blank treated in the step 2 into resin functional slurry containing a wave absorber for 3-5 minutes, blowing holes by adopting compressed air pulse of 0.3-0.5 MPa after the step is proposed, and then carrying out secondary heat treatment by adopting a step heating program to enable the aramid fiber honeycomb blank to reach a deep semi-cured state, and forming a wave absorbing functional layer on the outer side of a pure resin substrate layer in situ; step4, third-order impregnation Immersing the aramid fiber honeycomb blank treated in the step 3 into a third resin solution again for 1-2 minutes, blowing pores by adopting low-pressure compressed air of 0.1-0.2 MPa after the step is proposed, removing redundant liquid drops, and forming a pure resin sealing layer in situ outside the wave-absorbing functional layer; Step 5, curing and cross-layer co-curing after high temperature And (3) sending the aramid fiber honeycomb blank processed in the step (4) into a programmed heating curing furnace for high-speed Wen Zong curing, so that resin matrixes in the first-stage impregnating layer, the second-stage impregnating layer and the third-stage impregnating layer are subjected to cross-level cooperative curing, and finally forming a microcosmic sandwich hole wall structure formed by a pure resin base layer, a wave-absorbing functional layer and a pure resin cover layer which are distributed in sequence along the thickness direction of the honeycomb hole wall.
  2. 2. The method for in-situ manufacturing an aramid wave-absorbing honeycomb with a microscopic sandwich hole wall structure according to claim 1, wherein in the step 2, the first resin liquid is a high-permeability pure structural resin without solid filler, and the high-permeability pure structural resin is selected from one of low molecular weight novolac resin, bisphenol a type epoxy prepolymer and cyanate resin.
  3. 3. The method for in-situ manufacturing an aramid fiber wave-absorbing honeycomb with a microscopic sandwich hole wall structure according to claim 2, wherein in the step 2, the impregnating viscosity of the first resin liquid is 10-50 mPa-s, and the thickness of the formed pure resin substrate layer is 10-20 μm.
  4. 4. The in-situ manufacturing method of the aramid fiber wave-absorbing honeycomb with the microscopic sandwich hole wall structure is characterized in that in the step 3, resin functional slurry consists of a structural resin matrix, a toughening modifier and a radar wave absorbent uniformly dispersed in the structural resin matrix, wherein the absorbent is one or a combination of carbonyl iron powder, ferrosilicon aluminum powder, carbon nano tubes or graphene, and when the absorbent is magnetic powder, the mass fraction of the absorbent in the slurry solid content is 40% -75%.
  5. 5. The in-situ manufacturing method of the aramid fiber wave-absorbing honeycomb with the microscopic sandwich hole wall structure is characterized in that in the step 3, the impregnating viscosity of resin functional slurry is 300-800 mPa.s, and the step heating procedure is to heat the resin functional slurry for 30-45 minutes at 50-60 ℃ and then heat the resin functional slurry for 20-30 minutes at 110-130 ℃.
  6. 6. The method for in-situ manufacturing an aramid fiber wave-absorbing honeycomb with a microscopic sandwich hole wall structure according to claim 1, wherein in the step 4, the third resin liquid is a low-viscosity pure resin system rich in a cross-linking agent, and the impregnation viscosity is 10-30 mPa.s.
  7. 7. The method for in-situ manufacturing an aramid wave-absorbing honeycomb with a microscopic sandwich hole wall structure according to claim 6, wherein when an epoxy system is adopted, the resin matrix of the third resin liquid is bisphenol F type epoxy resin or alicyclic epoxy resin, and the cross-linking agent is aromatic diamine cross-linking agent or liquid methyl hexahydrophthalic anhydride.
  8. 8. The method for in-situ manufacturing an aramid wave-absorbing honeycomb with a microscopic sandwich hole wall structure according to claim 6, wherein when a phenolic system is adopted, the resin matrix of the third resin liquid is thermosetting phenolic resin with low relative molecular mass, and the crosslinking agent is melamine resin or hydrogen-containing silicone oil.
  9. 9. The method for in-situ manufacturing of the aramid fiber wave-absorbing honeycomb with the microscopic sandwich hole wall structure according to claim 1, wherein in the step 5, high Wen Zong curing comprises the following procedures of firstly preserving heat at 80-100 ℃ for 0.5-1 hour to remove residual solvents, then raising the temperature to 120-140 ℃ for 1-2 hours to promote continuous reaction and interlayer bonding of each layer of resin, and finally raising the temperature to 150-180 ℃ for 2-4 hours to realize overall heat curing.
  10. 10. An aramid wave-absorbing honeycomb structure, characterized in that the structure is prepared by the method of any one of claims 1-9; The honeycomb hole wall sequentially comprises a pure resin basal layer, a wave-absorbing functional layer and a pure resin sealing layer along the thickness direction, wherein the pure resin basal layer is positioned on one side close to aramid fiber, the wave-absorbing functional layer is positioned in the middle, and the pure resin sealing layer is positioned on the outer side, so that a microcosmic sandwich hole wall structure is formed; the wave-absorbing particles in the wave-absorbing functional layer are encapsulated inside the honeycomb hole wall; The pure resin basal layer, the wave-absorbing functional layer and the pure resin envelope layer are co-cured through the resin matrix to form an integrated hole wall composite structure.

Description

Aramid fiber wave-absorbing honeycomb with microcosmic sandwich hole wall structure and in-situ manufacturing method thereof Technical Field The invention relates to the technical field of honeycomb composite materials, in particular to an aramid fiber wave-absorbing honeycomb with a microcosmic sandwich hole wall structure and an in-situ manufacturing method thereof. Background The aramid paper honeycomb has the advantages of light weight, high specific strength, high specific rigidity, good heat resistance, easiness in sandwich compounding and the like, and is widely applied to lightweight sandwich structures such as aerospace, rail transit, radomes, unmanned aerial vehicles and the like. With the continuous improvement of the requirements of structural members on light weight, bearing and electromagnetic stealth performance, the structural function integrated aramid honeycomb material with mechanical support and electromagnetic absorption functions is attracting more and more attention. The prior wave-absorbing aramid honeycomb generally adopts post-treatment modes such as spraying, dipping or brushing on the surface of the wall of the formed honeycomb hole, and attaches wave-absorbing slurry to the surface of the hole wall. The method is simple and convenient, but the wave-absorbing layer mainly depends on surface adhesion, has limited interlayer bonding stability, is easy to generate local falling off, exposed particles and surface layer damage in the subsequent slicing, processing, assembling and service processes, and meanwhile, the wave-absorbing component exposed on the surface of the hole wall is easy to be influenced by damp and heat, oxidation, friction and environmental scouring, and has poor long-term stability. If the high-filling wave absorber is directly introduced into the honeycomb pore wall by adopting a single impregnation mode, the problems of poor slurry fluidity, pore canal blockage, local glue accumulation, out-of-control weight gain, uneven wave absorbing component distribution and the like are easily generated, and the problems are more obvious when the heavy magnetic absorber such as carbonyl iron powder, ferrosilicon powder and the like is used. Therefore, the prior art is difficult to simultaneously realize hole wall enhancement, wave absorbing function introduction and hole structural integrity maintenance. Therefore, in order to solve the above technical problems, the present application needs to provide an aramid wave-absorbing honeycomb having a micro sandwich hole wall structure and an in-situ manufacturing method thereof. Disclosure of Invention The invention aims to solve the defects in the prior art, and provides an aramid fiber wave-absorbing honeycomb with a microcosmic sandwich hole wall structure and an in-situ manufacturing method thereof, so that wave-absorbing functional components can be integrated in the inside of the hole wall in the honeycomb manufacturing process, thereby improving the integration level of the structure and the function and the service stability. In order to achieve the purpose, the invention adopts the following technical scheme that the in-situ manufacturing method of the aramid fiber wave-absorbing honeycomb with the microscopic sandwich hole wall structure comprises the following steps: Step 1, preparation of aramid honeycomb blank Coating node glue on the surface of aramid paper according to a preset stripe width, and stretching and shaping along the direction perpendicular to the stripe of the node glue after superposition, hot pressing and solidification to obtain an aramid honeycomb blank which is not impregnated with structural resin; Step2, first order impregnation Immersing the aramid fiber honeycomb blank obtained in the step 1 into a first resin liquid for 1-3 minutes, blowing out redundant glue solution in holes by adopting compressed air of 0.1-0.2 MPa after the step is proposed, and then performing primary heat treatment at 70-90 ℃ to enable the resin to reach a shallow gel state (Soft B-stage), so that a pure resin substrate layer is formed on the surface of the aramid fiber in situ; Step 3, second-stage impregnation Immersing the aramid fiber honeycomb blank treated in the step 2 into resin functional slurry containing a wave absorber for 3-5 minutes, blowing holes by adopting compressed air pulse of 0.3-0.5 MPa after the step is proposed, and then carrying out secondary heat treatment by adopting a step heating program to enable the aramid fiber honeycomb blank to reach a deep semi-cured state, and forming a wave absorbing functional layer on the outer side of a pure resin substrate layer in situ; step4, third-order impregnation Immersing the aramid fiber honeycomb blank treated in the step 3 into a third resin solution again for 1-2 minutes, blowing pores by adopting low-pressure compressed air of 0.1-0.2 MPa after the step is proposed, removing redundant liquid drops, and forming a pure resin sealing layer in situ outsid