Tunable elastic modulus of Ti6Al4V bio-inspired lattices fabricated by laser powder bed fusion for biomedical applications

Conventional metallic bone implants often suffer from stress-shielding and limited mechanical adaptability, necessitating the development of biomimetic lattice structures with tunable properties. In this study, a novel Ti6Al4V bio-inspired lattice, termed RaLak, was proposed to mimic bone architecture. The corresponding lattices, with relative densities of 20% and 30% and unit cell sizes of 2–4 mm, were fabricated using laser powder bed fusion (L-PBF) technology. Through experimental investigations, a comprehensive analysis was conducted to evaluate the mechanical behaviour of the proposed lattice in comparison with conventional triply periodic minimal surface (TPMS) lattices. The results indicate that the RaLak lattice exhibits enhanced mechanical performance, achieving an improved balance between stiffness and energy absorption relative to gyroid and diamond TPMS lattices. In particular, the energy absorption of RaLak shows an improvement of approximately 50% compared to the gyroid lattice at 30% RD with a 4 mm cell size. This behaviour is attributed to its hybrid architecture, which promotes more uniform stress distribution and progressive deformation. Furthermore, modified Gibson-Ashby based models were developed to establish relationships between lattice geometry and mechanical response. The proposed design strategy enables effective tuning of mechanical properties, demonstrating strong potential for load-bearing biomedical applications.