Wire arc additive manufacturing of Ti-6Al-4 V alloy: a review

Abstract

One of the notable additive manufacturing (AM) technologies, wire arc additive manufacturing (WAAM) also known as wire-arc directed energy deposition (DED-Arc), has become a promising processing method to economically build large-sized components with relatively reasonable accuracy and greater deposition rates compared to other additive manufacturing processes. Recent strides in WAAM have enabled the successful fabrication of Ti-6Al-4 V alloy for various engineering applications such as aerospace, automobile, and marine industries. However, there are many critical challenges in fabricating large scale titanium components in a near net shaped geometry. Considering various research efforts in this direction, the purpose of this review is to highlight the importance of WAAM and its effective utilisation in the fabrication of Ti-6Al-4 V components. First, this article outlines the basic physics of the WAAM process and how process parameters affect build quality and microstructure. Second, the innovative strategies adopted in WAAM in terms of its power sources and hybridisation with deformation treatments are outlined. Later, the microstructural evolution of WAAM Ti64 in as built, heat treated, and in situ deformed conditions is discussed. The role of microstructure in imparting mechanical properties as built and in various treated conditions is reviewed, and future research directions in structure-property correlations are summarised.