Recent advances toward damage-tolerant 3D-printed titanium alloys: Alloy design perspective

Twenty-year uninterrupted endeavor of titanium alloys printing has opened up a new paradigm in metal additive manufacturing (AM) to fabricate engineering components with required strength–density–corrosion combinations. Despite the remarkable advances in titanium AM, controlling the grain structure to print the parts with engineered microstructures, tailored mechanical properties, and minimum anomalies remains challenging. Numerous approaches have been implemented to address this challenge, such as printing parameter control, post-AM heat treatments, and thermomechanical processing. In addition to the aforementioned conventional approaches, novel techniques have been proposed that require employing hybrid manufacturing or developing the printer itself. One of the novel pathways in developing damage-tolerant 3D-printed titanium alloys lies in modifying or re-designing the alloy composition. This pathway strives to exploit the unique solidification conditions of AM processes, which are typically different than conventional manufacturing techniques such as casting, forging, and rolling. Hence, this review paper aims to scrutinize the pathway toward Ti alloy modification/re-designing, which can lead to damage-tolerant Ti parts being printed via various AM methods, targeting performance-critical applications.