Experimental Investigation and Optimization of the Effects of Manufacturing Parameters on Surface Quality, Geometric Tolerances, and Hardness of PLA Material Produced by FDM Method

Şahin A., Uz K. S., Cemaloğlu F.

Doğu Fen Bilimleri Dergisi, cilt.9, sa.1, ss.74-94, 2026 (Hakemli Dergi)

Özet

In this study, Polylactic Acid (PLA) material, which is widely preferred in industrial and academic fields, was used to produce test specimens using the Fused Deposition Modeling (FDM) method at a constant layer height (0.1 mm) with different nozzle temperatures (200 °C, 210 °C, 220 °C, and 230 °C) and different scanning strategies (Concentric, Rectilinear, Hilbert Curve, and Octagram Spiral). The aim was to investigate and optimize the effects of manufacturing parameters on surface roughness value (Ra), hardness (Shore D), dimensional accuracy, and environmental sustainability. Confidence testing was performed by applying the Anderson-Darling (AD) test using Minitab software, and ANOVA analysis was conducted. It was observed that the increase in nozzle temperature improved the rheological behavior of PLA material, strengthening interlayer adhesion and reducing the void ratio. The maximum density (ρ) value was determined to occur at 220 °C nozzle temperature with the Rectilinear scanning strategy. The highest hardness resistance was achieved with the Hilbert Curve scanning strategy due to its homogeneous structure against vertical loads. While results below the nominal value (25 mm) were obtained at low nozzle temperatures (200 °C) depending on the cooling rate, positive deviation was observed at high nozzle temperatures due to the spreading of PLA material. When examining the environmental cost of manufacturing parameters, it is evident that the complexity of scanning strategies directly affects carbon emissions.