Effects of printing parameters of fused deposition modeling on mechanical properties, surface quality, and microstructure of PEEK

Polyetheretherketone (PEEK) is an engineering thermoplastic with good biocompatibility and excellent mechanical properties. More importantly, PEEK is a promising biomaterial that could potentially be used to replace traditional metal or ceramic parts for biomedical and aerospace applications. Compared to other processing technologies for manufacturing PEEK parts, fused deposition modeling (FDM) has numerous advantages for forming functional parts of complex structures. However, a number of challenges still exist in successfully realizing FDM of PEEK owing to its high melting temperature and high viscosity. In this paper, the FDM method was applied to achieve 3D printing of PEEK. For the first time, finite element analysis (FEA) was used to simulate the melting conditions and fluidity of PEEK in a flow channel, in order to determine the parameters required to 3D print PEEK parts with sufficient surface quality and improved mechanical properties. The simulation results were further analyzed to instruct the design of future printing systems and optimize the printing parameters. In addition, several FDM experiments were performed to study the effects of various printing parameters, including the printing temperature, printing speed, and printing layer thickness, on the mechanical properties, microstructure, and surface quality of printed PEEK parts. The results suggest that using a higher heating temperature of 440 °C, a printing speed of 20 mm/s, and a small printing layer thickness of 0.1 mm can improve the density of PEEK parts, reduce internal defects, strengthen binding between 3D printed layers and infill filaments, and reduce surface roughness. All of these efforts will contribute to the development of improved 3D printing technologies for PEEK.