Experimental and Statistical Investigation of the Bending and Surface Roughness Properties on Three-Dimensional Printing Parts

摘要

This research is purposed to analyze the bending strength and surface roughness results of polylactic acid samples produced by fused filament fabrication. Using the experimental design method, the effect of fill density, layer thickness, infill, and raster orientation parameters on the bending and surface roughness performance of samples was investigated. In the study, the individual effects and interactions of the main four factors were analyzed using 2(3)3(1) mixed-level factorial design approaches. Whereas linear and honeycomb filled were preferred in the experimental design, 30 degrees, 60 degrees, and 90 degrees angles were used as raster orientation and 50 % and 100 % were used as fill density. In addition, 0.15 mm and 0.05 mm were printed as layer thicknesses. Samples were tested using a stylus profilometer (Mitutoyo SJ-301) to determine surface roughness characteristics, and the AUTOGRAPH AG-IS 100 KN was utilized to analyze the bending strength of the parts. In addition, fracture surfaces were analyzed by stereo microscope at various magnifications. The data were analyzed using the Minitab 19 software program. The most effective parameter for bending strength is the layer thickness with 40.02 %. In addition, it has been observed that the fast honeycomb fill pattern has higher strength than the linear fill pattern. Inversely to literature, according to our result, when the layer thickness is reduced, the surface roughness increases, because of the bubble on the surface of the printed sample. The results obtained from this study will provide preliminary information to the users in order to produce the parts that will provide the necessary requirements according to the usage area with minimum time and costs.