Al颗粒夹层CFRP复合材料力学及电磁屏蔽性能EI

CFRP复合材料具有优异的力学性能,在航空航天装备中有广泛应用,但是因其单层铺层内部的结构各向异性,单向纤维铺层对于垂直极化波的电磁屏蔽效能较弱。为应对日益复杂的电磁环境,保护电子元器件不受干扰,增强复合材料的电磁屏蔽效能显得尤为重要,本工作利用非连续Al颗粒在层间面内紧密排列,构建了一种层间面内含连续Al屏蔽层的CFRP复合材料,并研究了不同Al颗粒含量对复合材料电磁屏蔽效能和力学性能的影响规律。结果表明,随着Al颗粒含量的增加,CFRP复合材料的导电性和电磁屏蔽效能也随之增加,当聚合物中Al颗粒质量分数达到33.3%时,复合材料的面内电导率提高了3个数量级,在垂直于纤维方向上对频率为3~17 GHz的电磁波的电磁屏蔽效能提高了10 dB以上。随着Al颗粒含量的增加,复合材料层间剪切强度与弯曲强度出现先上升后下降的变化规律,当树脂中Al质量分数为33.3%时,复合材料的层间剪切性能提高了5.2%达到80.5 MPa,当树脂中Al质量分数为50%时,复合材料的弯曲强度提高了20%至1441.0 MPa,弯曲模量提高了10.2%达到101.83 GPa。由此可见,Al颗粒夹层CFRP复合材料可以实现力学性能和电磁屏蔽效能的同步提升,是一种具有广泛应用前景的结构-电磁屏蔽一体化复合材料。

Mechanical and electromagnetic shielding properties of Al particle sandwich CFRP composites

CFRP composites are widely used in aerospace due to their excellent mechanical properties, however, due to the anisotropy of the individual plies, the electro magnetic interference(EMI) shielding efficiency(SE) for vertically polarized waves of the unidirectional fiber laminates is poor. In order to protect electronics within these equipments from increasingly severe electromagnetic interference, it is particularly important to enhance the electromagnetic shielding efficiency of the CFRP. In this paper, Al particles were introduced and a conductive network was constructed in the CFRP interlaminar region by condensing the Al particles on the prepreg surface. The effects of different Al particle contents on EMI SE and mechanical properties of composites were studied. With the increase of Al particle contents, the electrical conductivity and the EMI SE of CFRP composites increase. When the Al mass fraction in the resin is 33.3%, the in-plane conductivity of the composites increases by 3 orders of magnitude, the EMI SE of the Al particle sandwich CFRP composites is improved by more than 10 dB in the frequency range of 3-17 GHz. With the increase of Al particle contents, the interlaminar shear strength and bending strength of the composites increase first and then decrease. When the Al mass fraction in the resin is 33.3%, the interlaminar shear strength (ILSS) of the composites increases by 5.2% to 80.5 MPa, and when the Al mass fraction in the resin is 50%, the bending strength of the composites increases by 20% to 1441.0 MPa and the bending modulus increases by 10.2% to 101.83 GPa. It can be seen that the mechanical properties and electromagnetic shielding effectiveness of the Al particles sandwich CFRP composite can be improved simutaneously. It is a kind of structure electromagnetic shielding integrated composite with broad application prospects.