β duplex phase Ti–Zr–Nb–Ag alloys with impressive mechanical properties, excellent antibacterial and good biocompatibility

In this research, a new series of β duplex phase Ti₅₀Zr₂₅Nb_25-xAg_x (x = 0, 1, 3 and 5 at. %) alloys were prepared by rapid solidification process. The microstructure, mechanical properties, antibacterial properties, ion release behavior and biocompatibility of the alloys were systematically investigated. The alloys were composed of β main phase and β minor phase, therefor the alloys exhibited a very low Young's modulus of 60-61 GPa, which can effectively reduce the stress shielding effect. The alloys possessed high strength and hardness, which is correlated to the grain refinement strengthening caused by rapid solidification process and solid solution strengthening caused by the addition of Ag. The release of Ag ion increased with the increasing of Ag content. The antibacterial properties also showed the same trend and the Ag5 alloy exhibited 99.1% antibacterial rate. Meanwhile, the alloys possessed good biocompatibilities obtained through cell live and dead staining experiments and cell proliferation experiments.