Tribological Properties of Fused Deposition Modeling-Printed Polylactic Acid and PLA-CF: Extrusion Temperature and Internal Structure

Abstract Additive manufacturing using fused deposition modeling (FDM) is widely recognized for its capacity to produce custom-designed components, yet challenges persist in tailoring material properties for tribological applications. This study investigated the influence of manufacturing parameters, including extrusion temperature, carbon fiber (CF) reinforcement, and internal structural design, on the friction and wear performance of FDM-printed polylactic acid (PLA) and PLA-CF composites. Samples were produced using extrusion temperatures from 190 °C to 240 °C, with two distinct internal geometries: one featuring two perpendicular intersecting walls forming a single node and the other three walls at 120-deg angles. Results show that extrusion temperatures in the 190–220 °C range yield stable friction coefficients (COF), while deviations from this range lead to instability due to insufficient material flow or thermal degradation. CF reinforcement significantly reduces COF and enhances wear resistance, albeit at the expense of increased wear on counter surfaces due to its abrasive properties. The internal structure substantially impacts performance, with the two-wall design more effectively minimizing wear and friction and the three-wall arrangement offering consistent COF across varying temperatures. These findings highlight the critical interplay between manufacturing parameters, material composition, and internal design in optimizing FDM-printed components for applications demanding high durability and low friction.