The influence of thermo-oxidative aging on the electromagnetic absorbing properties of 3D quasi-isotropic braided carbon/glass bismaleimide composite

摘要

The hybrid carbon/glass fibers reinforced polymer matrix composites (CF/GF-PMCs) used as structural materials of weapon systems often suffer high-temperature condition, leading performance degradation of them. The electromagnetic (EM) absorbing properties are essential for the survival of the weapon systems. However, the influence of thermo-oxidative aging on laws and mechanisms of EM absorbing properties of CF/GF-PMCs has not been reported. In this paper, the 3D quasi-isotropic braided CF/CF bismaleimide composites were newly designed, and its EM absorbing properties were investigated under thermo-oxidative aging. The results indicate that the aged composite has better EM absorbing properties than the unaged one. This is because of thermo-oxidative aging results in an uneven surface and numerous cracks and voids in the aged composite. The uneven surface of the aged sample could diffuse the incident EM wave. And the cracks and voids on the surface and interior of the aged sample could provide channels for the EM wave to enter into the aged samples. (C) 2019 Elsevier Ltd. All rights reserved.