From Single Scan Tracks to 3D Samples: Effect of Process Parameters on Quality of Ti-6Al-4V Produced by Means of Direct Energy Deposition

Direct Energy Deposition (DED) is an additive manufacturing technique suitable for producing big size metallic components and their repairing. Titanium alloys are suited for being processed using this technology, especially Ti-6Al-4V. Different combinations of laser power and scanning speed were used to build single scan tracks to evaluate the most suitable process window for this material. Then geometrical features, for example melt pool height and width, were considered to avoid undesired phenomena, such as keyhole and inter-layer pores formation. Some of the best parameters’ combinations were then used to carry on an in-depth investigation on cubic samples, in which different parameters, related to melt pools interaction, were varied (hatching distance and Z-step). Overall porosity, microstructure and hardness were evaluated to determine final component quality and process feasibility for this alloy. Once determined the optimum combination of parameters, tensile tests were carried out to assess mechanical properties.