Enhancement of mechanical properties of metamaterial absorber based on selective laser sintering and infiltration techniques

In this study, a 3D printing technology, selective laser sintering (SLS), and infiltration techniques were used to prepare a complex three-dimensional metamaterial absorber with high performance. The raw carbonyl iron (CI) powders were coated by polyamide12 (PA12), where the dissolution-precipitation method was used to improve their uniformity. The coated powders were then printed by SLS. The influence of laser power on the relative density of the composites was studied, where 18W was thought as the optimal laser power. And the SLS samples were infiltrated by thermosetting epoxy resin (EP, E-44) to increase their relative densities and strength. Me-chanical tests showed that the infiltrated composites have an ultimate tensile strength of 41.98 MPa, almost 15 times higher than those without infiltration. The final metamaterial absorber (MMA) exhibited the reflection loss below-10 dB in 2.7-18 GHz. The above results indicate that the fabricated processes proposed in this paper have great potential for the preparation of three-dimensional metamaterial absorbers.