Microstructure and properties of a novel ternary Ti–6Zr–xFe alloy for biomedical applications

A series of ternary Ti–6Zr-xFe (x = 4, 5, 6, 7 wt %) biomedical titanium alloy was designed to develop potential biomedical materials. The effect of the Fe content on microstructure, mechanical properties, Young's modulus, and electrochemical behavior was studied in depth. The developed Ti–6Zr-xFe (x = 4, 5, 6, 7 wt %) alloys are mainly composed of α and β phases. The results indicated that the grain size of the β phase in Ti–6Zr-xFe alloys decreased with the increase of Fe element. The increase of Fe content also caused the decrease of α phase fraction, increase of β phase fraction and formation of ω phase. Besides, the increase of Fe content improved the microhardness (264, 300, 328, and 348 HV) and ultimate tensile strengths (748, 829, 917, and 994 MPa) of Ti–6Zr-xFe alloys due to the contribution of solid-solution strengthening effect for higher Fe contents, the refined strength of the β phase and the dispersion strength of ω phase. Young's modulus of Ti–6Zr-xFe alloys was 90, 93, 93, and 94 GPa, which was lower than that of Ti–6Al–4V alloy. Moreover, the Ti–6Zr-xFe alloy with the addition of 4 and 5 wt % Fe displayed excellent corrosion resistance. These results show that Ti–6Zr-xFe alloys are potential biomedical materials.