Study on Parametric Optimization of Fused Deposition Modeling (FDM) Process

Abstract

Fused deposition modeling (FDM) is a unique rapid prototyping (RP) technique that uses plastic material in a semi-molten state to fabricate the products directly from a CAD model. FDM is an additive manufacturing method, and prototypes are made layer-by-layer through the addition of semi-molten plastic material onto a platform from bottom to top. Sectors including the medical implant industry need increasingly higher levels of dimensional accuracy, minimal surface roughness and specifically tailored mechanical properties. But traditional FDM methods do not effectively address these needs. Compared with some other conventional method the quality of the FDM fabricated part extensively depends on process variable parameters. The aim of this research work is to study the effect of process parameters such as layer height, infill, build speed, and build temperature on dimensional accuracy, surface finish, and mechanical properties (e.g. tensile strength) of FDM printed parts. Experiments were conducted using Taguchi’s design of experiments consisting of three levels of optimization for four factors. The Taguchi method was used to optimize effect input process parameters on dimensional accuracy, surface finish, and tensile strength. A series of experiments were conducted on parts produced using Flash forge 3D printer from ABS. To analyze the effect of each process parameters on part quality, Taguchi analysis, ANOVA, main effect plots, interaction plots, 3D Surface plots, and Contour plots were used. From the result obtained, response values show that the optimal setting of process parameters for dimensional accuracy (ΔW, ΔT and ΔL) are the layer height at 0.29 mm, infill at 15 %, build speed at 30 mm/min and build temperature at 220 ºC, which yield minimum ΔW 0.0048 at maximum value of S/N ratio 46.3752, ΔT 0.0044 at maximum value of S/N ratio 47.1309 and ΔL 0.0056 at maximum value of S/N ratio = 45.0362. Based on the S/N analysis, the optimal process parameters for surface roughness (Ra) are the same as the ones used for dimensional accuracy, yielding which give a minimum Ra = 7.779 µm at maximum value of S/N ratio - 17.8185. Results of Taguchi optimization indicates that the optimal FDM parameters for Tensile strength (UTS) are the layer height at 0.19mm, the Infill rate at 45 %, Build speed at 180 mm/min and the build temperature at 240 ºC which gives maximum UTS =39.094 MPa at maximum value of S/N ratio = 31.8422.