Effect of multi-infill patterns on tensile behavior of FDM printed parts

Abstract

Fused Deposition Modeling (FDM) is an extrusion-based additive manufacturing technique which growing rapidly due to its ability to fabricate complex parts directly from CAD models. In conjunction with its growing applications, the mechanical behavior of the FDM printed part needs thorough investigation for effective application as an end use functional part in various industries such as aerospace, automobile, mold and die, biomedical. Functional applications of FDM printed parts are affected due to their lower mechanical properties compared to injection molded parts. The assessment of the mechanical behavior of the FDM printed part is proved as challenging task due to the wide variety of the process parameters. In the present work, an attempt has been made to experimentally investigate the tensile behavior of FDM printed parts having multi-Infill patterns and different stacking of layer arrangements for different Infill density and raster orientations. Combined patterned parts are printed from two thermoplastic materials, viz. PLA and ABS having six different stacking sequences at three different levels of Infill density (i.e., 30%, 60% and 90%) and two different raster arrangements (i.e., 0° and 45°) and those are mechanically tested to obtain tensile properties. Further, the fractographic analysis was carried out to study various aspects of tensile failure modes for FDM printed multi-infill pattern samples. Combining two different infill patterns and layer stacking sequence improves tensile strength for 45° raster orientation samples and decreases tensile strength for 0° raster orientation samples when compared to a single pattern throughout. For 0° raster orientation, stacking sequence with all the layers are deposited parallel to loading direction offers more strength than multi-infill pattern samples. Whereas for 45° raster orientation, stacking sequence with all the layers parallel to loading direction offers lower strength than multi-infill pattern samples.