THE EFFECT OF VIBRATORY ARC WELDING ON THE MICROSTRUCTURE AND MECHANICAL PROPERTIES OF STRUCTURAL ADDITIVE MANUFACTURED TITANIUM ALLOYS

Vibration during the welding process can affect the metal by changing the microstructure in several ways: The vibration breaks up the dendrites, thus reducing the porosity and the residual stresses during the solidification in the fusion zone. In addition, uniform and refined grains grow around broken dendritic particles. The objective of this research is to study the influence of the vibratory arc-welding process on the additive manufactured (AM) titanium, for the first time. The microstructure, chemical composition and mechanical properties of Ti-6Al-4V specimens prepared by powder bed fusion with electron-beam energy source were determined using optical microscopy, scanning electron microscopy (LV-SEM), energy dispersive X-ray spectroscopy (EDS) and hardness tests. The results were compared to those for AM Ti-6Al-4V TIG welded without vibration as well as to those for conventional wrought Ti-6Al-4V alloy. A comparative analysis is made in relation to three zones: the fusion zone, the heat-affected zone, and the interface between them.