Investigation on effect of pillar size on the comprehensive properties of Ti6Al4V lattice fabricated by selective laser melting

To investigate the effect of pillar size on the mechanical properties of Ti6Al4V lattice fabricated by selective laser melting (SLM), seven groups of Ti6Al4V lattice structures with different pillar sizes were fabricated by SLM technology. The compression process of the lattice structure of body-centered cubic element was studied by numerical simulation method, and then the numerical simulation results were verified by experiments. The porosity of the lattice structure was characterized by dry weight method, and the compressive and compressive fatigue properties of the lattice structure were tested. The results showed that the actual porosity of all lattice structures with different pillar sizes was less than the designed porosity due to the thermal adsorption of the surrounding powder on the pillar. The numerical simulation was in good agreement with the experimental results, which can be used to predict the displacement changes in the elastic region of the lattice structure. With the increase of the pillar size, the difference between the actual porosity and the designed porosity of the lattice structure increased first and then decreased. The compression resistance of the unit cell topology was better. Meanwhile, the compression and yield strength of the lattice structure were increased. The larger the pillar size of lattice structure, the better the plasticity. It can withstand higher cyclic load and have better fatigue performance.