Recycling of Ti-15Mo and Ti-13Nb-13Zr alloys and their use in additive manufacturing

Recycling of titanium alloys represents a modern and economically attractive processing route, as it enables a significant reduction in production costs associated with the high price of titanium. However, the properties of recycled β-titanium alloys have not yet been sufficiently investigated in the scientific literature, and their potential for processing by additive manufacturing technologies remains largely unexplored. This study focuses on evaluating the recycling of Ti-15Mo and Ti-13Nb-13Zr alloys using the horizontal plasma arc melting (HPAM) method and further examines subsequent processing steps, including hot working to the required shape for atomisation and subsequent powder processing via the LPBF technique. In all technological stages, the microstructure was characterised, chemical analysis was performed, and, where applicable, mechanical properties were evaluated. The results demonstrate that recycling of the investigated alloys is feasible, as is their subsequent processing up to the production of additively manufactured specimens. Nevertheless, strict control of the oxygen content is critical for both alloys, as the current levels exceed the limits specified by the relevant standards. At such elevated oxygen concentrations, the alloys are unsuitable for biomedical applications; however, their use in structural applications remains realistic, particularly considering the production cost reduction achieved through the implementation of recycling.