Study on fused deposition modeling forming and properties of Ni/PLA/TPU composite microwave absorbing material

The development of “wide-band, high-strength” microwave absorbing materials is the basis of preparing high-efficiency absorbing devices. Based on the preparation of Ni/TPU/PLA mixed powder, Ni/PLA/TPU composite wires were prepared by melt extrusion process. Furthermore, the coaxial rings and tensile specimens were fabricated rapidly using fused deposition modeling technology, and the effects of Ni content on the mechanical and microwave absorbing properties of the composites were investigated. The results show that the distribution of Ni in PLA/TPU matrix is discrete when the content of Ni is low (less than 60%), and continuous distribution is formed when the content of Ni is high (more than 70%). When the Ni content was 50%, the tensile strength was 35.4 MPa, which was 12.1% higher than that of the pure PLA/TPU. The complex permittivity and complex permeability of the composite increased with the increase of Ni content, and the complex permittivity and complex permeability were higher when the Ni content was 80 wt%, which means that it has strong dielectric loss and magnetic loss. The minimum reflection loss is − 17.73 dB, and the effective bandwidth is 5.44 GHz (10.32–15.76 GHz). The prepared Ni/PLA/TPU composites have high strength and wide-frequency characteristics, thus providing the possibility to prepare complex and high-efficiency microwave absorbing devices.