Enhancing Mechanical Performance of 3D-Printed PEEK via Vacuum Infiltration

Polyether ether ketone (PEEK) is a thermoplastic polymer renowned for its ex-ceptional thermal resistance, mechanical strength, durability, chemical re-sistance, and low density. PEEK can be additively manufactured using various techniques, including Power Bed Fusion (PBF) and Material Extrusion (ME). Among these, ME stands out for its ease of operation and cost-effectiveness. Op-timizing printing parameters and thermal post-processing are crucial for enhanc-ing the mechanical and thermal properties of printed parts. In this study, the effect of an infiltration process by a high-performance thermosetting epoxy resin on the flexural properties of PEEK has been investigated. Moreover, a comparison with respect to as-printed specimens has been carried out. Results revealed that infil-trated PEEK exhibits a 27,4% higher flexural strength, with an average value of 93,84 MPa, and a 12,5% higher flexural modulus, averaging at 3311,44 MPa. Furthermore, the strength-to-weight ratio and stiffness-to-weight ratio both ex-perienced improvements in specimens subjected to infiltration. Notably, as-printed PEEK displayed increased susceptibility to delamination under flexural stress, demonstrating a more brittle fracture behavior compared to infiltrated specimens. In summary, the findings indicate that the developed infiltration post-processing method shows potential for improving the mechanical properties of additively manufactured PEEK.