Mechanical characteristic comparison of additively manufactured Ti–6Al–4V lattice structures in biocompatible bone tissue growth

Abstract

This study proposed the development of Ti–6Al–4V lattice structures suitable for the growth of bone cells using laser powder bed fusion (PBF) and heat treatment of vacuum furnace tubes. The designed and fabricated Diamond (DIA), Trifolium (TF), and Trishuriken (TS) lattice structures had high mechanical strength and Young's modulus similar to human cancellous bone. The pore size, porosity, compressive strength, and internal defect of the lattice structures are also discussed herein. According to the experimental observations, after the holding temperature at 950 °C for 1, 2, and 3 h, the grain sizes of TS500 samples were 3.59, 5.05 and 7.87 μm2, respectively. The compressive strength and ductility of these lattice structures changed significantly after the heat treatment. Two kinds of internal defects appeared in PBF production, namely, the powder that did not melt completely during printing and the micro-spherical pores caused by the residual gas. These were found concentrated at the middle location of the cross of the laser scanning path. Furthermore, the defect distribution can be detected through micro computed tomography.