Material Extrusion Additive Manufacturing of Composite Laminates: Printability and Characterizations

This study characterizes composite laminates produced via Material Extrusion Additive Manufacturing (MEAM) using combinations of polylactic acid (PLA), recycled PLA (rPLA), and ultrafuse 316 L stainless steel. A thorough analysis of the effect of layer frequency on the material behavior of the PLA/rPLA, PLA/316 L stainless steel, and rPLA/316 L stainless steel composites was conducted. Owing to the disparity in deposition temperatures, PLA and rPLA layers exhibited poor adhesion to 316 L stainless steel layers, likely exacerbated by warping during printing. Excess material deposition at layer pauses caused bobbles at the corners of material interfaces, which in certain samples led to the formation of ridges. Additionally, layer sliding was observed, attributed to weak adhesion both to the print bed and at some layer interfaces. The rPLA layers demonstrated superior load-bearing capacity, while composite laminate block samples with higher interlayer frequencies exhibited enhanced resistance to compressive forces. This study provides insights into the challenges and mechanical performance of multi-material composite laminates, highlighting areas for process optimization and material improvement.