Porous NFG/SiCnw composites fabricated by SLS for structural load-bearing and functionally integrated electromagnetic absorption

In this work, porous NFG/SiCnw composites for structurally functionally integrated electromagnetic microwave absorption were fabricated using selective laser sintering 3D printing technology and high-temperature sintering process based on the preparation of a hybrid powder of natural flake graphite (NFG), silicon (Si) and phenolic resins (PF). The effects of adding Si powder on the properties of NFG/SiCnw composites were investigated. The green body prepared by SLS has a rich microporous structure. By varying the amount of Si powder added, the open porosity of the composite and the growth and structure of SiC nanowires can be controlled, resulting in efficient absorption of electromagnetic waves. It was shown that the porous NFG/SiCnw composite exhibited efficient electromagnetic microwave absorption with a minimum reflection loss of -51.10 dB and an effective absorption bandwidth of 5.04 GHz (12.96-18 GHz) when the Si powder addition was 20 wt% and the thickness was 1.5 mm. The bulk density, open porosity, and compressive strength of the porous NFG/SiCnw composites were 0.76 g/cm3, 68.17%, and 2.89 MPa, respectively. SLS 3D-printed porous NFG/SiCnw composites combine microwave absorption with structural load-bearing and are highly promising for industrial electromagnetic wave absorption applications.