Assessing the compressive and tensile properties of TPMS-Gyroid and stochastic Ti64 lattice structures: A study on laser powder bed fusion manufacturing for biomedical implants

In the field of additive manufacturing, the design and fabrication of lattice structures have garnered substantial attention, particularly for their potential in advanced material applications. This study focuses on the mechanical properties of titanium alloy Ti64 lattice structures fabricated by Laser Powder Bed Fusion. It examines the mechanical features of two structure types, TPMS Gyroid and Stochastic Voronoi, analyzing their design and fabrication interplay. To evaluate mechanical properties, two methodologies to compute stress were employed: Method A, nominal diameter calculations of the cross-sectional area as a bulk material, and Method B, averaged cross-sectional area measurements along the open-cell porous structures. Method A generally showed lower Elastic Modulus and Yield Stress than Method B, highlighting the importance of geometric accuracy in lattice design mechanics. Both TPMS gyroid and stochastic lattices, within a 0.1-0.5 relative density range, displayed mechanical properties similar to human bone, suggesting their potential in orthopedic use. This could help reduce stress shielding and improve implant lifespan. The findings were further complemented by Scanning Electron Microscopy and Digital Image Correlation evaluations, highlighting the intricate relationship between fabrication parameters, lattice morphology, and the emergent microstructural characteristics.