Experimental Studies on the Mechanical Behaviour of Three-Dimensional PLA Printed Parts by Fused Filament Fabrication

摘要

Abstract The present work focuses on evaluating the mechanical strength of parts fabricated by Fused Filament Fabrication (FFF) based on input variables, i.e. build orientation (XY, XZ and YZ), infill density (20 to 100) and annealing temperature (60?°C and 120?°C). The XY orientation exhibits maximum elongation at break as 14.67 for 100 infill density. The ultimate tensile stress obtained for XY orientation is 45.089?MPa which is much higher as compared to XZ (39.256?MPa) and YZ (27.05?MPa) at 100 density. After annealing, 3D printed samples exhibit an improvement in mechanical properties but ductility is decreased. The tensile strength is increased by 14 when annealed at 120?°C as compared to not-annealed specimen for 100 infill density. Also, Surface roughness (Ra) increases from 1.14?μm at 20 infill density to 1.895?μm at 100 (an increase of 66). However, annealing the specimen at 120?°C, Ra decreases from 1.895?μm to 1.454?μm (decrease by 23). Fractography of tensile tested parts exhibit different characteristics and fracture modes. Further, Flexural testing is performed for best tensile testing parameters exhibiting maximum flexural strength of 56.12?MPa for XY, 100 density, 60?mm/s feed rate and 0° raster orientation combination.