Additive Manufacturing of Ti-Based Alloys: Microstructure, Mechanical Properties, and Corrosion Behavior

Implementation of rapid prototyping additive manufacturing (AM) has revolutionized and accelerated applications of materials in manufacturing aviation components, personalized prosthetics, and implants with complex geometries and microstructures. Due to its highly-versatile material processing and precise structure control, AM has been widely employed in manufacturing titanium (Ti) and its alloys, as seen in AM-based techniques, including fused deposition modeling (FDM), techniques based on powder bed fusion (PBF) including selective laser sintering (SLS), selective laser melting (SLM), and electron beam melting (EBM), and methods based on direct energy deposition (DED) such as laser engineered net shaping (LENS) and wire arc additive manufacturing (WAAM). Processing Ti alloys, however, is a challenging task due to its complications associated with the processing parameters and the influences on structures and properties of manufactured parts or products. In this paper, we review the AM of Ti and its alloys, focusing on the microstructure of AMed Ti-based parts or products and their mechanical and corrosion properties. This study also addresses the potential of AM methods for the production of complicated components, including cellular structures, and their utilization in the aviation and medical fields. Key challenges and trends of the FDM, PBF-based, and DED methods are also identified and discussed, along with recommendations for future studies on AM-fabricated Ti alloys for improved properties.