Impact of Printing Orientation on the Mechanical Properties of Selectively Laser Sintered PA12

Abstract

This study explores the impact of different printing orientations in the selective laser sintering (SLS) process on the mechanical properties of polyamide 12 (PA12). Test specimens were developed according to ASTM D3039 using three distinct orientations: 0°, 45°, and 90°. Tensile tests were performed to evaluate the Young's modulus and ultimate tensile strength of each specimen tested. To complement the experimental analysis, finite element models were developed in ANSYS APDL.The models developed incorporated the Gurson-Tvergaard-Needleman (GTN) damage model, which accounts for material porosity, as well as the Chaboche model to simulate plastic deformation behavior. The numerical simulations performed closely match the experimental results, confirming the reliability of the proposed models. Microscopic observations were carried out to examine the microstructure of the printed material. The observations revealed variations in the distribution of defects and porosity and demonstrated that this originates from the printing orientation of the material. For certain orientations, the specimens showed more uniform microstructures and fewer defects, which correlates with better mechanical properties, such as increased stiffness and strength. These results highlight the very important role of printing orientation in optimizing the structural integrity and mechanical performance of PA12 components manufactured by SLS, while validating the predictive capacity of the numerical approach.