High-performance Al2O3-modified PETG/carbon fiber sandwich nanocomposites fabricated through FFF 3D printing coupled with hand lay-up

: This work aims to describe the structure, strength and heat resistance of carbon fiber (CF)-embedded polyethylene terephthalate glycol (PETG–CF) sandwich nanocomposites that have different amounts of Al 2 O 3 nanoparticles, made via the FFF 3D Printing coupled with Hand Lay-up process. The PETG-CF laminates made via the FFF route of additive manufacturing are bonded together with the intermediate layer of Al 2 O 3 -reinforced epoxy. The effect of varying Al 2 O 3 nanoparticle contents in the intermediate layer on the tensile behavior of the developed nanocomposite laminate was investigated according to ASTM standards. Microstructural studies of the 3D-printed PETG–CF laminate, hybrid composite laminate structure, distribution of nano-reinforcements, interfacial bonding, and the effect of tensile loading were carried out using FESEM. The influence of incorporating 2.5%, 5%, 7.5%, and 10% Al 2 O 3 nanoparticles on the tensile strength of PETG–CF/Al 2 O 3 nanocomposites is reported. The incorporation of Al 2 O 3 nanoparticles significantly enhanced the mechanical and thermal performance of the PETG–CF sandwich composites. The tensile strength increased from 63.2 MPa for the baseline PETG–CF laminate to 135.5 MPa at 10 wt.% Al 2 O 3 , representing an improvement of over 100%. Thermogravimetric analysis further indicated improved thermal stability with increasing nanoparticle content, with the highest residue retention observed at 10 wt.% Al 2 O 3 .