3D printing of continuous fiber reinforced thermoplastic composites: Effect of process parameters in X-band microwave absorption performance

The present work investigates the effect of process parameters on the microwave absorption performance of 3D printed continuous carbon fiber reinforced polylactic acid composites in the X-band (8-12 GHz). The selection of process parameters in this work is based on an orthogonal experiment, explicitly focusing on the fiber orientation and printing temperature. The coupled effect between fiber orientation and printing temperature on the average absorptivity is further investigated by using response surface methodology (RSM), and the mechanism of these parameters on the microwave absorption performance is revealed, resulting in the optimal process parameters with a fiber orientation of 58.39 degrees and a printing temperature of 230 degrees C. The predicted average absorptivity is 0.525 and the mechanical properties of specimens corresponding to optimal parameters have been characterized. The experimental results demonstrate that the optimization of process parameters could lead to a significant improvement in the average absorptivity. Moreover, the microstructure observation shows that voids have the opposite effect on microwave absorption performance and mechanical properties. The above studies have specific guiding significance to the further application of 3D printed continuous fiber reinforced thermoplastic composites in structural absorbing materials.