Deformation behavior of metastable β-type Ti–25Nb–2Mo–4Sn alloy for biomedical applications

The deformation behavior of metastable β-type Ti–25Nb–2Mo–4Sn (wt%) alloy subjected to different thermo-mechanical treatments was discussed by the combining results from transmission electron microscope, tensile test and in-situ synchrotron X-ray diffraction. Visible “double yielding” behavior, which is characterized by the presence of stress-plateau, was observed in the solution treated specimen. Upon a cold rolling treatment, the Ti–25Nb–2Mo–4Sn alloy performs nonlinear deformation because of the combined effects of elastic deformation and stress-induced α″ martensitic transformation. After the subsequent annealing, the β phase is completely stabilized and no stress-induced martensitic transformation takes place on loading due to the inhibitory effect of grain boundaries and dislocations on martensitic transformation. As a result, the annealed specimen exhibits linear elastic deformation. The nonlinear deformation of the cold rolled Ti–25Nb–2Mo–4Sn alloy is attributed to the combined effects of elastic deformation and stress-induced α″ martensitic transformation. [Display omitted] •Ti–25Nb–2Mo–4Sn alloy can perform different deformation behavior.•The nonlinear deformation is involved in stress-induced martensitic transformation.•Martensitic transformation occurs over a wide stress range in the cold-rolled alloy.