Electromagnetic and mechanical properties of carbonyl iron powders-PLA composites fabricated by fused deposition modeling

3D printing is an emerging additive manufacturing method for effectively fabricating materials with complex structures. Fused deposition modeling (FDM) is one of the most popular 3D printing techniques, usually used for making thermoplastic parts. However, this method has been rarely considered for designing and fabricating radar wave absorbing structures, which can be very helpful to achieving intricate structures with good mechanical and wave absorbing properties. To verify the validity of this method, carbonyl iron particles filled thermoplastics composites are fabricated by FDM in this study. The morphological, magnetic, electromagnetic and mechanical properties of the composites are investigated by scanning electron microscopy, vibrating sample magnetometer, broad band dielectric spectrometer and universal testing machine. The composites exhibit the hysteretic loops of typical soft ferromagnetism with relatively low remanence, coercive force, and hysteresis losses. The saturation magnetization per unit mass of iron powders of the composites does not have a linear relation with filler contents. The obtained composites materials possess slightly improved tensile strength and significantly improved total elongations than materials obtained by traditional manufacture methods. This 3D printing process will enlighten a rational design of composites with complex shapes, and can also be extended to other thermoplastics based composites, including ABS, PC, and PA.