Sample building orientation effect on porosity and mechanical properties in Selective Laser Melting of Ti6Al4V titanium alloy

Abstract

In recent decades, the focus of research has shifted towards new production technologies with the aim of optimizing production and reducing costs. These innovative technologies include additive manufacturing processes as Selective Laser Melting (SLM). The analysis of the literature on the identification of optimal building orientation to maximize the mechanical properties and minimize porosity of the final products highlights contrasting results, denoting that the thermomechanical complexity of the process, as associated with the variation of the building orientation, has not been fully clarified. A study in which the building orientation effect was evaluated together with the geometry of the sample and characterized as a function of the preferentially active heat exchange phenomena was carried out with the aim to provide guidelines for the choice of the orientation angle. Heat accumulation phenomena observed in SLM were taken into account to define three geometrical parameters able to identify the causes of the decrease of mechanical properties due to incorrect choice of the orientation angle.