Improved mechanical properties of Ti-6Al-4V alloy by electron beam welding process plus annealing treatments and its microstructural evolution

In this study, we investigated the effect of post weld annealing treatments on the mechanical properties of a Ti-6Al-4V alloy following electron beam welding (EBW). The operational parameters used in this EBW process together with suitable annealing treatments appeared to substantially enhance the tensile properties of the Ti-6Al-4V weldment, suggesting that EBW is a promising method for industrial application. Moreover, we report for the first time that gamma-TiAl + alpha(2)-Ti3Al formed in the fusion zone of the Ti-6Al-4V EBW weldment and exhibited the same lamellar structure, orientation relationship, deformation mechanism, and slip system as common Ti-Al-based alloys do. The presence of these intermetallic compounds affected the mechanical properties of the weldment. We discuss the related phase transformation, microstructural evolution, and characteristics of the precipitates formed. (C) 2014 Elsevier Ltd. All rights reserved.