选择性激光烧结制备的具有微网络结构的增强型SiC/NFG/Ni三元复合吸波材料

Abstract

Abstract: In this study, a mixed powder of natural flake graphite (NFG), thermosetting phenolic resin (PF), silicon carbide (SiC), and mullite (MC) was initially fabricated. Subsequently, SiC/NFG/Ni composite absorbent materials were fabricated through selective laser sintering (SLS) forming and impregnation process. The study investigated how the content of SiC powder affected the absorption capacity and mechanical properties of the composites. The consequences demonstrate that the porosity decreases with the increase of SiC content, and the bending strength increases with the increase of SiC content. As the content of SiC is 40 wt%, the porosity is 52.14% and the flexure strength is 9.58 MPa, approximately five times greater than that of graphite-type ceramic preforms. And the wave-absorbing property shows a tendency of enhancing and then weakening with the increase of SiC content. When the SiC content is 10wt% and the thickness is 2.4 mm, the composite absorbing material exhibits optimal electromagnetic absorption performance, with a minimum reflection loss (RLmin)of -39.02 dB and an effective absorption bandwidth (EAB) of 6.0 GHz (9.60-15.60 GHz). This is primarily due to the substantial accumulation of SiC, resulting in a decrease in the number of pores within the composite material, while simultaneously increasing its density. This demonstrates that the incorporation of SiC improves its mechanical strength. Thereby influences the amount of electromagnetic wave reflections within the material, leading to changes in both its wave-absorbing properties and mechanical properties. The light weight, high strength and wide frequency of the prepared composite wave-absorbing material. It is anticipated that this material will prove applicable in the realm of microwave absorption.

Keywords: SiC/NFG/Ni composite wave-absorbing materials, selective laser sintering (SLS) forming technology, vacuum pressure impregnation, micro-network architecture enhancement，mechanical properties, electromagnetic wave-absorbing properties