Desirability-Based Multiobjective Optimization of Layer Thickness, Infill Density, and Print Speed in Sustainable Carbon–Polylactic Acid Fused Deposition Modeling
摘要
Carbon-filled polylactic acid produced by fused deposition modeling is a sustainable feedstock for lightweight structural parts, but performance depends on process-controlled porosity and interlayer fusion. The coupled effects of layer thickness, infill density, and print-path speed on simultaneous tensile, impact, and hardness performance in carbon–PLA systems remain insufficiently quantified. This study aims to define a multi-response analysis for carbon–PLA FDM. Eighteen coupon sets were fabricated in a factorial design spanning 0.15-0.25 mm layer thickness, 20-60% infill, and 60-80 mm min−1 paired raster-angle/print-path conditions, then evaluated by tensile, Charpy impact, and hardness testing with response-surface modeling and desirability optimization. Tensile strength ranged from 12.61 to 24.81 MPa, impact strength ranged from 11.21 to 14.70 J mm−2, and hardness ranged from 79 to 93 HR; these values demonstrate process sensitivity. Infill density dominates tensile and impact performance, layer thickness controls hardness, and the desirability optimum was 0.661 at 0.2079 mm, 60% infill, and 80 mm min−1, with predicted responses of 19.916 MPa, 13.950 J mm−2, and 87.579 HR. These results support parameter selection for mechanical performance, and future work should validate the optimum and relate the surfaces to porosity and fracture morphology.