Evaluation of the roughness of lattice structures of AISI 316 stainless steel produced by laser powder bed fusion

Abstract

The present work evaluates the surface roughness of lattice structures produced in AISI 316 stainless steel, with laser powder bed fusion (LPBF). To this end, five lattice types were evaluated, namely cubic (C), truncated octahedron (TO), truncated cubic (TC), rhombicuboctahedron (RCO) and rhombitruncated cuboctahedron (RTCO) to determine the average roughness S_a by profilometry. For comparison, the surface roughness of a bulk specimen was also measured.

The average roughness was S_a=7.3 mm for the bulk specimen, for the C and TC arrangements it was around 11 mm, while for configurations RCO, RTCO and TO it was in the range 18-22 mm, meaning that surface roughness increases for more complex structures. Values of S_a around 10-25 mm are reported in the literature for parts fabricated by LPBF for medical implants. If complex lattice arrangements are required, a study of the printing parameters is relevant, to achieve scaffolds with improved biomechanical performance.