In-situ chemically synthesized Fe3O4/K-geopolymer composite with microwave absorbency for additive manufacturing
In this work, we utilized an in-situ chemical synthesis method to fabricate a Fe 3 O 4 /K-geopolymer (KGP) composite to be applied in a microwave absorbent field. This material, as a type of ceramic precursor, is highly expected to be a 3D printing material to prepare microwave absorbing components with complex shapes. The investigation results demonstrate that the material possesses a large effective microwave absorbing bandwidth of 3.7 GHz with the minimum reflection loss reducing to −12.2 dB when the generated Fe 3 O 4 percent reaches 12 wt% in the KGP composite. This microwave absorbent performance can be attributed to a synergistic effect between the eddy current loss caused by the improved electrical conductivity of magnetic nanoparticles and the interfacial polarization effect from the geopolymer matrix and magnetic medium interface. Also, we used direct ink writing technology to print two-dimensional components with desirable patterns. Thickness-dependent wave absorption evaluation results confirmed a maximum reflection loss of −25.9 dB at 15.2 Hz was obtained from the printed sample containing 9.0 wt% Fe 3 O 4 for a layer thickness of 10 mm, indicating that wave consumption effectiveness was determined by porous microstructures, magnetic loss of Fe 3 O 4 nanoparticles as well as suitable impedance matching. The preparation method and synthesized material pave the way for integrated manufacturing of 3D printing components with microwave absorbing performance.
危险品化学品经营许可证（带存储）