Microstructural evolution and mechanical properties of a novel biomedical Ti–6Zr–4Fe alloy during solution and aging treatment

Microstructural evolution and its effect on microhardness and Young's modulus of Ti–6Zr–4Fe alloy solution and aging treated at different temperatures were studied. The α phase transformed into β phase completely at 860 °C, meanwhile, the athermal ω phase was found at 860 °C and it resulted in a higher Young's modulus. The ω phase content increased from 250 °C to 400 °C, and the content decreased with further increase of aging temperature, there were only α phase and β phase at 600 °C. The phase transformation sequence was β → ω + β → ω + α + β → α + β during aging treatment. The microhardness increased from 315 HV to 492 HV due to the element solution strengthening and phase transformation strengthening. The peak microhardness of Ti–6Zr–4Fe alloy aged at 400 °C reached 652 HV. The formation of ω phase resulted in the increase of microhardness and Young's modulus in Ti–6Zr–4Fe alloy.