Experimental and numerical assessment of surface roughness for Ti6Al4V lattice elements in selective laser melting

Additive manufacturing (AM) such as selective laser melting (SLM) enables the fabrication of complex lattice structures. These lattice structures are efficiently fabricated for a variety of applications, such as aerospace components and biomedical implants. The SLM process inherently introduces local temperature fields, resulting in local thermal defects, including porosity, partially fused particles, and dimensional errors. These defects introduce variation between the intended and manufactured geometries. This research provides an extensive experimental and numerical assessment of these geometric effects on individual lattice strut elements. These effects are quantified by systematic methods, allowing roughness of SLM lattice struts to be correlated with associated geometric control factors, i.e. length of strut, Ls, diameter of strut, Ds, and manufacturing inclination angle, α. Robust correlation is found between experimental and numerical data; resulting in a methodology for a priori prediction of thermally induced defects based on input geometry.