Effect of Printing Parameters on Mechanical Properties and Warpage of 3D-Printed PEEK/CF-PEEK Composites Using Multi-Objective Optimization Technique

Polyether ether ketone (PEEK) is a high-performance thermoplastic widely used in aerospace, automotive, and medical applications due to its exceptional strength, heat resistance, and chemical stability. However, warpage and mechanical property variations remain significant challenges in 3D printing PEEK parts. This study investigates the effect of key printing parameters, including nozzle temperature, layer thickness, platform temperature, and infill rate, on the mechanical properties and warpage of 3D-printed PEEK components. By systematically analyzing tensile and compressive loading conditions, this research aims to optimize printing settings to improve dimensional accuracy and structural integrity. The experimental results indicate that mechanical properties, such as tensile and compressive stress at break, vary significantly with printing conditions. The highest tensile strength and compressive strength achieved were 71.4 MPa and 167 MPa, respectively. Meanwhile, the lowest tensile (45.36 MPa) and compressive strengths (72.5 MPa) were also recorded. Higher nozzle and platform temperatures, coupled with increased infill rates, enhance layer adhesion, leading to improved tensile and compressive strength. However, a nozzle temperature of 400 °C, platform temperature of 130 °C, and 60% infill rate lead to optimal bonding between layers and thus a reduction in warpage. Considering warpage in all four corners and mechanical properties, a 400 °C nozzle temperature, 0.16 mm layer thickness, and 130 °C platform temperature, coupled with a 60% infill rate, provide optimal printing conditions. The 10% carbon fiber-reinforced PEEK composites exhibit an improved tensile strength that is 1.68 times higher compared to pure PEEK. To emphasize the importance of thermal and structural settings, the findings highlight the crucial role of printing parameters in minimizing warpage and enhancing mechanical properties in 3D-printed PEEK parts, which were analyzed by the multi-objective optimization method. Scanning electron microscopy analyses were carried out to analyze fracture morphology and printing layer orientation.