Manufacturability of Ti-6Al-4V Hollow-Walled Lattice Struts by Laser Powder Bed Fusion

Hollow-walled lattices are novel cellular materials with lower densities than conventional dense-walled lattices. However, their manufacturability by laser powder bed fusion (LPBF) is not yet established. This study investigates the LPBF manufacturability of Ti-6Al-4V hollow-walled struts with respect to strut outer diameter, wall thickness (controlled by laser scan path), and inclination angle, while the strut length is purposely limited to 10–15 mm, typical of lattice unit dimensions. The manufacturability was reliable for outer diameters exceeding 0.5 mm and wall thicknesses exceeding 0.24 mm over the inclines of 22.5°–90°. To ensure a manufacturable hollow cylindrical channel by LPBF, we recommend a minimum inner diameter of 4Dv(90) according to the feedstock powder size distribution. The average inconsistency of 5.13% between the designed and manufactured outer diameters was substantially lower than that achievable by conventional manufacturing. The findings of this study provide necessary guidance for the future manufacture of hollow-walled lattices by LPBF.