4D打印热塑性聚氨酯/钕铁硼磁性复合材料成形工艺与性能研究

Research on Processing and Properties of 4D Printed Thermoplastic Polyurethane/NdFeB Magnetic Composites

传统的3D打印技术逐渐无法满足高端制造领域对构件的要求,材料-结构-功能一体化增材制造即4D打印技术将是新的发展方向。为此,选取热塑性聚氨酯(TPU)/钕铁硼(NdFeB)磁性复合材料体系,采用激光选区烧结(Selective laser sintering,SLS)工艺成形具有不同Nd FeB含量的复合材料成形件,研究了复合粉末的粒度及其分布、微观形貌、成形前后化学基团演变,成形件晶体结构、力学性能及变形行为,结果表明Nd Fe B含量会影响复合材料成形件的力学性能和变形行为,增加Nd Fe B含量能够增大成形件在磁场中受到的作用力;当Nd Fe B含量在复合材料中质量分数为30%时,复合材料成形件拥有最佳的拉伸强度。本研究将TPU/NdFeB复合材料体系作为一种创新的4D打印材料,成形的磁性智能构件在磁场中发生变形,实现了磁场驱动的4D打印,对4D打印磁性智能构件的发展具有指导意义。

It is gradually unable for the traditional 3 D printing technology to meet the requirements of components in the high-end manufacturing field. The material-structure-functional integrated additive manufacturing, that is, 4 D printing technology will be a new development direction. Therefore, in this work, the thermoplastic polyurethane(TPU)/NdFeB magnetic composite is applied into the selective laser sintering(SLS) process to fabricate parts with different NdFeB content. The particle size and its distribution and micromorphology of the composite powder are investigated. The chemical group evolution before and after forming, crystal structure, mechanical properties and deformation behavior of the SLS printed parts are also studied. The results show that the NdFeB content have influence on the mechanical properties and deformation behavior of the composite parts. The force exerted on the composite parts enhances with the increase of NdFeB content. The fabricated part with 30 wt% NdFeB have the best tensile strength. In this study, the TPU/NdFeB composite material system is used as an innovative 4 D printing material. The formed magnetic intelligent component can deform when exposed to magnetic field, which indicate the magnetic field driven 4 D printing is realized. As a result, this work has guiding significance for the development of 4 D printed magnetic intelligent components.