Influence of Line Energy Density on the Ductility of Ti6Al4V L-PBF Parts for Hybrid Metal Forming Applications

Abstract

In the last decade have been developed many hybrid metal forming processes that foresee the integration of commonly used sheet metal forming processes, such as bending, deep drawing, spinning, and incremental forming, with the metal additive manufacturing process as the Powder Bed Fusion technology Selective Laser Melting. These integrations have been developed more in the productive sectors characterized by the request of components with complex geometries in small numbers such as, for example, the aerospace sector. Hybrid additive manufacturing overcomes the typical limitations of additive manufacturing related to low productivity, metallurgical defects, and low dimensional accuracy and promotes new applications with traditional manufacturing processes. In this perspective, obtaining parts characterized by high strength and ductility becomes a key aspect in the development of hybrid processes. In the present work samples of Ti6Al4V alloy were printed using the SLM additive manufacturing technology and the influence of process parameters, such as the Linear Energy Density on the ductility of material was studied. The characterization of the samples was performed through tensile tests to determine the mechanical characteristics of the material and by OM analysis of the fracture surface of tensile tested specimens. Further density analysis, using the principle of Archimedes, allowed quantifying the porosity defects.