Mechanical properties of Ti-Nb-Zr-Ta-O biomedical alloyThursday (29.09.2016) 09:45 - 10:00 Part of:
Recently developed biomedical alloy Ti–35.3Nb–7.3Zn–5.7Ta–0.7O (wt.%) abbreviated as TNZTO is unique in its high oxygen content and exhibits promising properties for successful use in orthopaedics. Material was prepared by sequential pour casting in form of rod with diameter of 55 mm, allowing for orthopaedic implants manufacturing. Unusually high oxygen content causes increased strength and, interestingly, good ductility with elongation > 15%. Tensile tests were performed using the as-cast material and material after high-temperature die forging. As-cast material showed yield stress > 800 MPa, whereas yield stress of die-forged material exceeds 1000 MPa. Flow curves exhibit sharp yield point, which suggests interactions between interstitial oxygen atoms and dislocations. A series of as-cast samples was further annealed at 400-500°C/1-16h. Alpha phase particles were observed by SEM along high angle beta/beta grain boundaries. The microhardness tests were performed on the as-cast, die-forged and annealed conditions.