High layer thickness influence on melt pool sizes and defects appearing of Ti6Al4V at high scan speeds

Abstract

Layer thickness presents one among the most critical input process parameters in Selective Laser Melting (SLM) once it has a direct influence on the defects appearing in the printed parts, such as porosity. The objective of this study is to predict the influence of a wide range of layer thickness on melt pool geometries and, consequently, on defects generation of Ti6Al4V alloy produced by SLM through a series of numerical simulations. This manuscript also demonstrates porosity evolution as a combination of increasing both layer thickness and scan speeds. Results show that the melt pool sizes are almost similar under various layer thicknesses for all single beads with minor discrepancies in the melt pool measurements employing different high scanning speeds. Although, the morphology of the melt pool indicates clear changes among various thicknesses, in fact, increasing layer thickness combined with increasing scan speed seriously deteriorates the part quality during SLM process. The simulation results agree with experimental ones.