Carbon Nanotube/Fused Silica Composite with Gradient Structure and Carbon Fiber/ Fused Silica Back Reflection Layers for Microwave Absorbing Application

摘要

A microwave absorbing material with laminated structure was designed and fabricated by hot-pressed sintering. Pure fused silica (SiO_2) was applied as upper face layer of the laminated composite in order to decrease the reflection to incident microwave. Two layers of SiO_2 matrix composites with 2.5 and 5 wt% carbon nanotubes (CNTs) were designed as microwave absorbing layers. Continuous carbon fiber (C_f)/SiO_2 was used as bottom layer to reflect the penetrating microwave. The results showed that the laminated composite was fabricated and all interfaces were clear. This unique four-layer composite had an improved microwave absorbing efficiency in X-band compared with the single-layer and two-layer composites of CNT/SiO_2 containing considerable content of CNTs.