Mechanical and dielectric properties of continuous glass fiber reinforced poly-ether-ether-ketone composite components prepared by additive manufacturing

This work aims to examine the mechanical and dielectric properties of continuous glass fiber (CGF) reinforced poly-ether-ether-ketone (PEEK) composite (CGFRPCs) with different fiber content prepared by additive manufacturing. To address the problems of fiber breakage during the preparation of continuous fiber composite filaments and the low fiber content of 3D printed components, a stepped filament preparation die is proposed and designed, and the influences of die form on the micromorphology and mechanical properties of filaments, as well as the influence of die diameter on the micromorphology, fiber content, mechanical properties and roundness of filaments during the preparation of CGFRPCs filaments are examined. In addition, the influence of dies with different diameter on the mechanical strength of the specimens printed by their prepared filaments is examined, and finite element analysis is utilized to analyze the mechanical strength and interlayer failure process during the flexural damage process of the printed specimens via Hashin fracture criterion and cohesive contact model. Finally, the influence of fiber content on the dielectric properties of the 3D printed specimens are examined. The results show that the stepped die can significantly reduce the degree of breakage of the filament and improve the mechanical strength of its printed specimens. The reduction of the die diameter improves the fiber content and roundness of the filaments. The 0.8 mm die formed filament and its printed specimen reach the highest tensile strength of 1114.63 MPa and 730.21 MPa, respectively. In addition, the flexural strength, interlaminar shear strength, and impact strength of the printed specimens reach the maximum values of 562.54 MPa, 43.88 MPa, and 180 kJ/m² at die diameter of 0.9 mm, 0.85 mm, and 1.2 mm, respectively. The results of the dielectric properties reveal that the dielectric constant and dielectric loss tend to increase with the increase of fiber content.