Effect of nanosilica on low‐velocity impact and compression after impact properties of continuous carbon fiber‐reinforced epoxy composites manufactured by 3D printing

Abstract To improve the low‐velocity impact (LVI) and compression after impact (CAI) properties of three‐dimensional (3D)‐printed continuous carbon fiber‐reinforced epoxy composites (CFRC), nanosilica (NS) was incorporated into these composites. NS (0.5 and 1 wt%) was dispersed in a liquid epoxy matrix by ultrasonication and mechanical stirring before mixing in a planetary mixer. The addition of NS up to 1 wt% did not render any processing barrier during the extrusion followed by the automated tape placement (ATP) method, adopted in this study. The resulting “hybrid” laminates showed void content <1% and had minimal internal defects as ensured by nondestructive technique (C‐scan) and scanning electron microscopy. The neat and NS‐loaded CFRPs were subjected to an impact energy of 6 J mm⁻¹. The rebound energy increased by ~36% with the addition of 1 wt% NS as compared to unfilled samples, obtained from the LVI test. The CAI results suggest that with 1 wt% NS the residual compressive strength increased by ~13% in comparison with the neat CFRP laminates. After impact, the damage area was reduced significantly, that is, ~62% with the addition of 1 wt% NS in comparison with the neat CFRP laminates.