Mechanical properties of HA@Ag/PLA nanocomposite structures prepared by extrusion-based additive manufacturing.

This research deals with understanding the directional mechanical performance of polylactide (PLA) thermoplastic polymer during 3D-printing based on material extrusion technology, as influenced by the incorporation of silver-modified hydroxyapatite (HA) nanoparticles between layer-upon-layer deposits. Formation of perfect bonding between the stacked layers upon additive manufacturing (AM) consolidation and homogenous dispersion of developed nanoparticles between the layers characterized in correlation with the induced thermo-mechanical history during the deposition process. Subsequently, by conducting tensile, bending, and impact energy tests across different sections, the ultimate level and anisotropy in mechanical properties of produced 3D-layered nanocomposite structures were assessed. The results revealed the admirable dependency of mechanical properties on the testing plane specifically for the Z-section compared to the others, which indicates the strong vertical bonding between the layers as its impact effect significantly improved by the role of HA@Ag nanoparticles. The optimized consolidated nanocomposite material exhibited an excellent combination of various mechanical properties for a polymer-based structure that under the extreme state they can express as the tensile strength of up to ~120 MPa, bending strength of up to ~90 MPa, and absorbed impact energy of up to ~17 J/m.