A novel Ti42.5Zr42.5Nb5Ta10 multi-principal element alloy with excellent properties for biomedical applications

Body-centered cubic (BCC) Ti–Zr–Nb–Ta multi-principal element alloys (MPEAs) have drawn extensive research attention as orthopedic implant materials. In this work, a novel Ti42.5Zr42.5Nb5Ta10 multi-principal element alloy was developed for biomedical applications in terms of its microstructure, mechanical properties, wear performance, corrosion behavior, and in vitro biocompatibility. The Ti42.5Zr42.5Nb5Ta10 alloy after cold rolling followed by annealing at 880 °C (TZNT-880), possessed excellent mechanical properties combination, with a yield strength of 839.5 MPa, elongation at fracture of 22.6%, and Young's modulus of 63.2 GPa, superior to most of the currently existing biomedical BCC MPEAs. Meanwhile, TZNT-880 alloy exhibited higher wear resistance compared with commercial CP-Ti and Ti6Al4V, which is strongly related to its high H/E and H3/E2 values. Also, TZNT-880 alloy showed good corrosion resistance, as revealed by a nobler corrosion potential, lower corrosion current densities, and higher passivation stability, which is attributed to the formation of passivation films consisting of TiO2, ZrO2, Nb2O5, and Ta2O5. The in vitro biocompatibility tests demonstrated that the TiZrNbTa alloys can support cell adhesion and proliferation with high biocompatibility comparable to that of CP-Ti and Ti6Al4V, indicating their potential as a candidate for implant material.