Mechanical behaviour of Ti6Al4V lattice structures manufactured by electron beam melting

Additive manufacturing (AM) technologies enable the design and production of complex geometries, including structures engineered to achieve enhanced mechanical performance. Among these designs, there is growing interest in utilizing metal lattice structures, with specifically required properties, minimizing weight, for applications in both the mechanical and medical fields. The mechanical properties of such structures are strongly influenced by their shape and size. This study aims to investigate the influence of lattice topology, cell dimensions and beam diameter on the deformation and failure mechanisms of Ti6Al4V alloy lattice structures manufactured by EBM under compressive loading. A Design of Experiment (DOE) was adopted to define the unit cell geometry and dimensional parameters of the specimens. Sixteen topological configurations were obtained, and forty-eight lattice specimens (three replicas per configuration) were manufactured in random order to minimize process-related variability. Experimental results were analysed both in absolute terms and as a function of lattice density. In addition, a detailed optical microscopy analysis was performed to statistically evaluate beam diameters and actual cell dimensions. X-ray micro-computed tomography (micro-CT) was also employed to assess the presence of internal defects, such as porosity, which may affect the mechanical behavior.