Microwave absorption properties of double-layer structured basalt fiber/resin composites containing carbon black and nano-Fe3O4

Basalt fibers (BF)-reinforced double-layered resin composite with excellent absorption performance in X band (8.2-12.4 GHz) has been designed, choosing carbon black (CB) and nano-Fe3O4 as absorbent for absorbing layer and matching layer, respectively. The electromagnetic parameters of the composites were measured by vector network analyzer using waveguide method. The calculated result suggests that an increased amount of absorbent could significantly improve the microwave absorbability of the single-layered composites in the measured frequency. For double-layered composites, the optimum microwave absorption performance can be obtained by tailoring the electromagnetic parameters and thicknesses of each layer. The minimum reflection loss of -43.97 dB and full X band effective absorption can be achieved when the thickness of the matching layer (BF/Fe(3)O(4)10) and absorbing layer (BF/CB7.5) were 0.3 mm and 2.7 mm, respectively. Therefore, utilization of dielectric loss, magnetic loss absorbent and BF/resin double-layered structure has designed flexibility, and contributes to promote the development of high-performance microwave absorbing composites.