Additively manufactured Ti6Al4V lattice structures: mechanical characterization and numerical investigation

The interest in manufacturing complex devices with integrated extra-functional properties is steadily growing for high technological application fields, such as the aerospace and biomedical ones. Among advanced methods of manufacturing, additive manufacturing allows to produce complex three-dimensional geometries, like lattice structures, which possess mechanical and functional properties unachievable by their constituent materials. The present work investigates Ti6Al4V lattice structures produced by Selective Laser Melting (SLM) through a combined experimental and numerical campaign. The effects of the relative density of the elementary cell, building direction (along horizontal and vertical building directions), and sample condition (as-built and heat treated at 850°C) on the mechanical properties of the lattice structures are investigated through tensile testing. Finite element analysis is performed to analyze the stress/strain distribution due to the different investigated effects. The results provide useful insight into the deformation/failure mechanisms, stress concentrations, and mechanicalproperties of the studied structures as well as into their correlation to the relative density and printing process parameters. The resulting performances of the lattice structures are compared with the ones of the bulk samples.