Mechanical properties of additively manufactured variable lattice structures of Ti6Al4V.

Engineered micro- and macro-structures via additive manufacturing (AM) or 3D-Printing can create structurally varying properties in part, which is difficult via traditional manufacturing methods. Herein we have utilized powder bed fusion-based selective laser melting (SLM) to fabricate variable lattice structures of Ti6Al4V with uniquely designed unit cell configurations to alter the mechanical performance. Five different configurations were designed based on two natural crystal structures - hexagonal closed packed (HCP) and body-centered cubic (BCC). Under compressive loading, as much as 74% difference was observed in compressive strength and 71% variation in elastic modulus, with all samples having porosities in a similar range of 53 to 65%, indicating the influence of macro-lattice designs alone on mechanical properties. Failure analysis of the fracture surfaces helped with the overall understanding of how configurational effects and unit cell design influence these samples' mechanical properties. Our work highlights the ability to leverage advanced manufacturing techniques to tailor the structural performance of multifunctional components.