Authors:
T. Mossop (1), DJ Browne (1), M. Celikin (1)
1- School of Mechanical and Materials Engineering, University College Dublin, Dublin, Ireland
Abstract:
Processing β-titanium (Ti) alloys via metal additive manufacturing (AM) has high potential to be used for biomedical applications, hence understanding their solidification behaviour under rapid cooling is critical. The solidification structures of Ti-niobium-tantalum (Ti-Nb-Ta) based alloys were investigated under various cooling rates (c. 2,000-20,000 K/s) using rapid solidification suction casting. An anti-solute trapping effect was determined for a ternary Ti-Nb-Ta alloy. In relatively slower-cooled samples, the microsegregation was in line with Scheil-Gulliver theory, however under more rapid cooling, the microsegregation increased significantly. This anomalous microsegregation had the effect of stabilizing additional α/α’- and β-phase content of the as-solidified ternary alloy – reducing the otherwise favoured martensitic α’’ content and resulting in a dual-phase structure where the dendrites are primarily β-phase and the interdendritic regions are α’’ martensite.
DOI:
https://doi.org/10.59499/EP246281565
