A review on wire and arc additive manufacturing of titanium alloy

Wire and arc additive manufacturing (WAAM) is considered to be an economic and efficient technology that is suitable to produce large-scale metallic components. In the past few decades, it has been widely investigated in different fields such as aerospace, automotive, and marine industries. Due to its relatively high deposition rate, low machinery cost, high material efficiency, and shortened lead time compared to other powder-based additive manufacturing (AM) techniques, WAAM has been significantly noticed and adopted by both academic researchers and industrial engineers. Titanium alloys as valuable metallic materials have been increasingly applied in aeronautics and astronautics fields owing to their excellent comprehensive properties. However, there are many challenges to fabricate large-scale titanium components with traditional manufacturing methods, particularly in consideration of complex component geometries and high Buy-To-Fly (BTF) ratio. Therefore, due to the advantages of relatively low manufacturing cost, good quality, and high efficiency, WAAM is becoming popular to fabricate near-net-shape and large-scale titanium alloy in recent years. This paper provides an overview of the 3D metallic printing of titanium alloy by employing WAAM as the deposition method. At first, the review introduces titanium alloys and WAAM technique, followed by WAAM systems which are used to manufacture titanium, and post-treatment which aims to optimize microstructure, improve mechanical properties, and eliminate residual stress of the WAAM deposited titanium components. Afterward, the economic applicability of applying WAAM on titanium alloys is also discussed. In the end, applications in various fields of WAAM titanium components are displayed.