Superior Lightness-Strength and biocompatibility of bio-inspired heterogeneous glass sponge Ti6Al4V lattice structure fabricated via laser powder bed fusion

Abstract

Ti6Al4V lattice structures (LSs) have great potentials in medical implants due to their excellent biocompatibility and high strength-to-weight ratio. This paper investigates the manufacturability and performance of unique Ti6Al4V heterogeneous glass sponge (GS) LSs fabricated via laser powder bed fusion (LPBF). Compared with the commonly used LSs, including Cross, body-centered cubic (BCC), Diamond and octet-truss (OCT), Ti6Al4V GS LSs exhibit the strongest compressive strength and energy absorption ability of 58 MPa and 23.84 J/cm3, respectively. Finite element (FE) models are established to evaluate the macroscopic deformation, microscopic stress and strain evolution in the solid struts of five different LSs. Local plastic stresses are found to generate near the nodes of Cross, BCC, Diamond and OCT LSs, thus forming plastic hinges, while the GS LSs can evenly transfer local plastic stresses to the grid-like rods of each layer, eventually showing a uniform stress distribution. Moreover, all the LSs are featured with satisfactory biocompatibility concerning cytotoxicity, cell proliferation, and cell attachment. The results indicate that the Ti6Al4V GS LSs can address the conflict between lightness and strength simultaneously, thus achieving excellent energy absorption performance, compressive properties and great biocompatibility, endowing it with tremendous application potential in the field of medical implants.