Study of Physical Properties of Additively Manufactured and Post-processed 3D Porous Structures Intended for Implants

The work aimed to determine the effect of finishing porous three-dimensional structures manufactured with additive technologies such as Selective Laser Sintering (SLS) and Fused Deposition Modeling (FDM) on their physical properties. The work focuses on the influence of the material, type of surface treatment as well as the thickness and height of the strut forming the tested structures on their surface quality, the degree of porosity, and compressive strength. Moreover, the compatibility of the 3D printed porous structure to the developed 3D model designed in the CAD software was also analyzed. The test samples were made of polyamide PA12 (SLS technology) and PLA (FDM technology). Depending on the 3D printing technology used, the impact of different types of finishing was assessed. The scope of the research included: mass measurement, determination of geometrical features, porosity examination by gas pycnometry, macroscopic observations, and static compression test. The analysis of the obtained results showed that with the use of SLS technology, the 3D physical model is characterized by greater accuracy compared to the model manufactured in FDM technology. It was also found that the smaller the strut height and thickness of the porous 3D structure, the more compressive strength the structure has. In the case of finishing 3D printing, it was found that for SLS technology, sandblasting with glass beads is the optimal treatment, while for models printed by the FDM method - annealing.