Investigation of the structure and mechanical properties of additively manufactured Ti-6Al-4V biomedical scaffolds designed with a Schwartz primitive unit-cell

Additively manufactured porous metallic structures have recently received great attention for use in hard tissue applications. In particular, periodic regular porous networks are found to be very promising in terms of mechanical performance and compatibility with the host tissue. This work investigates for the first time three different types of porous Ti-6Al-4V structures manufactured using selective laser melting (SLM) using a solid network based on a Schwartz primitive unit-cell. Both internal features and microstructure of the SLM-produced samples were investigated. A good consistency in both strut size and pore size was observed between the produced structures. The results of uniaxial compression testing were compared with results calculated using the finite element method (FEM) modelling. The results of mechanical testing for the 64% porous samples match the properties of cortical bone, with a stiffness of 22.3 GPa and a yield strength of 160 MPa. A minimal pore size of 596 µm was achieved, which is within the recommended suitable range for bio-integration. A comparison between the numerical models and the experimental results suggest that the geometrical inaccuracy caused by powder adhesion has an insignificant impact on the static mechanical properties.