铁镍合金/聚乳酸复合材料的熔融沉积成形制备及其电磁吸收性能和力学性能

Electromagnetic absorption properties and mechanical properties of Fe-Ni alloy/polylactic acid composites fabricated by fused deposition modeling

在制备铁镍合金(FeNi50)/聚乳酸(PLA)复合线材的基础上,利用熔融沉积成形(FDM)制备出FeNi50/PLA复合材料。采用SEM、振动样品磁强计、矢量网络分析仪和万能试验机研究了FeNi50对复合材料微观形貌、磁性、电磁性能和力学性能的影响,并讨论了其反射损耗。研究发现,复合材料的饱和磁化强度和电磁性能随着FeNi50含量的增加而增加,使其反射损耗得到改善并向低频偏移。采用两步混合工艺使FeNi50颗粒相对均匀地分布在聚乳酸基体中,形成了类似海岛状的结构。这种结构阻止了FeNi50团聚并隔离了涡流,从而改善了吸波性能;得益于上述分散结构,球形颗粒分布在裂纹扩展方向上,吸收了断裂能量,使复合材料的断裂延伸率相比纯PLA提高了31.7%。表明这种基于FDM的FeNi50/PLA复合材料在吸波和承载方面具有较好的应用潜力。

The Fe-Ni alloy/polylactic acid(FeNi50/PLA) composite was prepared using fused deposition modeling(FDM) by PLA/FeNi50 composite filaments with different contents of FeNi50. Effects of FeNi50 on the micromorphology, magnetic properties, electromagnetic properties and mechanical properties of the composites were investigated using SEM, vibrating sample magnetometer, vector network analyzer and universal testing machine, and the reflection loss of composites were discussed. The results show that the saturation magnetisation strength and electromagnetic properties of the composites gradually increase as the FeNi50 content, resulting in improved reflection loss and a shift towards to low-frequency. The two-step mixing process enables FeNi50 particles to be distributed relatively uniformly in the PLA matrix, forming an island-like structure, which prevents FeNi50 agglomeration and isolates eddy currents, thus improving microwave absorption performance. Thanks to the above dispersion structure, the spherical particles are distributed in the crack extension direction, which absorbs the fracture energy and increases the elongation at break of the composites by 31.7% compared with the pure PLA. It is shown that the FDMbased FeNi50/PLA composites have good potential for microwave absorption and load-bearing applications.