3D-Printed high performance PEEK/CF-PEEK polymer composites—An investigation on microstructural characteristics and mechanical performance

This study investigates the microstructural characteristics and mechanical properties of 3D-printed polyether ether ketone (PEEK) and carbon fiber-reinforced PEEK (PEEK CF20) composites. Using a specifically optimized 3D printing process parametric condition, samples of pure PEEK and PEEK CF20 (containing 20% carbon fiber) were fabricated. Mechanical properties were estimated by tensile, flexural, and interlaminar shear strength (ILSS) tests, performed as per ISO and DIN standards. Results indicated that PEEK CF20 exhibits significantly enhanced mechanical properties compared to pure PEEK. The tensile strength of PEEK CF20 was 81.069 MPa, compared to 76.070 MPa for pure PEEK. Maximum load values were 1456.608 N for PEEK CF20 and 1286.137 N for pure PEEK, while ILSS values were 15.76 MPa for PEEK CF20 and 11.82 MPa for pure PEEK. Microstructural analysis through field emission scanning electron microscopy (FESEM) revealed that PEEK CF20 had better fiber-matrix bonding and fewer defects compared to pure PEEK.