Preparation and microwave absorption mechanism of arrayed carbon fiber composite materials
Carbon materials like carbon fibers have such advantages as light weight,good conductivity and strong chemical stability.It could improve the reflectivity and service life,and it can effectively reduce the weight of the carbon material filled electromagnetic absorbing materials.Here,carbon fibers with array distribution were prepared by the process of"orientation optimization-matrix encapsulation".The morphology and chemical composition of the material were characterized by SEM and FT-IR.The complex permittivity and permeability of the material were measured from 2 to 18 GHz by a vector network analyzer.The effects of microstructure were analyzed on the electromagnetic parameters,interface impedance matching and electromagnetic wave absorption performance.Finally,the effect of arrangement structure,composition and weight ratio on the wave absorption performance was studied through above characterization.It indicates that the electromagnetic loss is due to dielectric loss,interference cancellation,interface polarization relaxation,and magnetic loss.The result show that the reflectivity is less than-10 dB from 6.1 to 7.6 GHz,and the maximum attenuation value and thermal conductivity were-15.2 dB at 6.5 GHz and 3.2 W/(m·K)at 2.0 mm thickness,respectively.