Newly developed Ti–10Mo–6Zr–4Sn–3Nb has fascinating mechanical properties to be used as a biomedical material. However, there is still a lack of investigation focusing on the corrosion behavior of Ti–10Mo–6Zr–4Sn–3Nb. In this work, the microstructure and corrosion behavior of as-cast Ti–10Mo–6Zr–4Sn–3Nb was investigated by optical microscopy, X-ray diffraction, and electrochemical measurements. Hank’s solution was used as the electrolyte. A classical as-cast Ti–6Al–4V was used as reference. The results showed that Ti–10Mo–6Zr–4Sn–3Nb has a higher corrosion potential and a lower corrosion current density compared with Ti–6Al–4V, indicating better corrosion resistance. However, after applying anodic potentials, Ti–10Mo–6Zr–4Sn–3Nb shows larger passivation current density in both potentiodynamic polarization and potentiostatic polarization tests. This is because more alloying elements contained in Ti–10Mo–6Zr–4Sn–3Nb trigger the production of a larger number of oxygen vacancies, resulting in a higher flux of oxygen vacancy. This finding illustrates that the passive film on Ti–10Mo–6Zr–4Sn–3Nb is less protective compared with that on Ti–6Al–4V when applying an anodic potential in their passivation range.

The precipitation behavior and microstructural evolution of α phase in a novel metastable β-type Ti alloy, Ti-10Mo-6Zr-4Sn-3Nb (wt.%), during isothermal compression are investigated in this study through the use of SEM (scanning electron microscope), TEM (transmission electron microscope) (HRTEM) (high-resolution transmission electron microscopy) and EBSD techniques. The results show that some finer α precipitates are randomly distributed within the β matrix during hot deformation. The morphological characteristics of α precipitates are distinctly different from those of α precipitates during the same solution-plus-aging treatment. The volume fraction of α precipitate gradually increases with increased true strain. A large proportion of precipitated α phases are prone to be precipitated at HAGBs (high-angle grain boundaries) and LAGBs (low-angle grain boundaries) during isothermal deformation. On the contrary, only a small amount of spherical α phases is precipitated within the β grain. The crystallographic orientation relationships for most spherical α precipitates formed at LAGBs and within the β grains are similar, whereas the crystallographic orientation relationships for α precipitates at grain boundaries are significantly different. The precipitation behavior of α phase in the Ti-B12 alloy during hot compression is considerably influenced by the density of dislocations.

The deformation behavior of Ti-3.5Al-5Mo-6V-3Cr-2Sn-0.5Fe high strength β titanium alloy is systematically investigated by isothermal compression in α + β field with the deformation temperatures ranging from 1003 K to 1078 K, the strain rates ranging from 0.001 s⁻¹ to 1 s⁻¹ and the height reduction is around 50%. Essentially, the flow stress-strain curve of isothermal compression in α + β field exhibits a flow softening feature when the strain rate is higher than 0.1 s⁻¹ as while it exhibits a steady-state feature as the strain rate is lower than 0.1 s⁻¹. The peak stress increases with a decrease in deformation temperature and the increase of strain rate. The activation energy for deformation in α + β field was calculated and the average activation energy of 271.1 kJ/mol. The microstructure observation reveals that the isothermal deformation in the α + β field of the alloy is mainly controlled by the dynamic recovery mechanism accompanied with the secondary dynamic recrystallizitation of β phase. The α phase shows an obvious pinning effect for the movement of dislocations. During deformation, the α phase was elongated and fragmented.

The influences of process annealing temperature during cold rolling on microstructure and mechanical properties of Ti-3.5Al-5Mo-6V-3Cr-2Sn-0.5Fe near β high strength titanium alloy sheets have been investigated. Results showed that the alloy mainly included the deformation induced dislocation structures after cold rolling but no obvious band structure, twin crystal or martensite were observed in this work. The texture components, which were affected by process annealing, are mainly γ-fiber, α-fiber and weak Goss texture. The γ-fiber of alloy when process annealed at 780 °C (α/β phase field) is stronger than at 830 °C (β phase field), where the Goss texture of alloy with process annealing temperature of 830 °C is more obvious. Results of annealing heat treatments showed that the recrystallization of the cold rolled was basically completed in a relatively short time of 2 min at 750 °C for 2 min. The refinement of grain size led to a significant increase of plasticity compared to rolled alloy. Results of tensile testing of aged alloy display the excellent combination of strength and plasticity, and the cold rolled alloy with process annealed at α/β phase field exhibits the better mechanical properties than at β phase field.