Effect of laminated structures on thermo-formability of continuous CF/PEEK composites

Carbon fiber reinforced polyether-ether-ketone composites (CF/PEEK) are increasingly used in aerospace and other fields. In this study, the influence of laminated structures on mechanical properties and thermo-formability of CF/PEEK sheets were investigated, and the associated mechanisms were discussed. Six different laminated structures of CF/PEEK sheets were designed, and the sheets were fabricated under the same process parameters. The mechanical properties and thermo-formability were characterized by tensile tests at 0° and 90° directions and Erichsen tests at 320℃, respectively. The results show that the tensile strength and thermo-formability of orthogonal structure 0/90/0/0/90/0 is the best. However, the thermo-formability of the structure added woven laminates or non-orthogonal structure are decreased. This is because the added woven laminate is observed to be a weak part in the structure, and the non-orthogonal structure has distinct mechanical properties in 0° and 90° directions and is prone to fiber-matrix failure.