Influence of cold rolling on the elastic modulus, mechanical strength, and electrochemical behavior of β-type titanium alloys for biomedical applications

Achieving a superior combination of low elastic modulus and high strength is essential for expanding the biomedical and aerospace applications of β-titanium alloys. In this study, a Ti-28Nb-4Zr-4Sn-1Mo-1Ta alloy was subjected to cold rolling with thickness reductions of 20% and 40% to clarify the effects of deformation-induced microstructural evolution on its mechanical and electrochemical behavior. At 20% cold rolling, coarse plate-like stress-induced martensite with a width of 200-500 nm formed together with a pronounced {111}<112> γ-fiber texture, increasing the elastic modulus from 49.4 GPa in the solution-treated state to 53.7 GPa. With further deformation to 40%, the martensite evolved into dispersed nanoscale domains, which offset the texture-induced increase in elastic modulus, lowering it to 44.1 GPa. Meanwhile, the yield strength increased continuously from 207.2 MPa to 272.4 MPa and finally to 534.5 MPa, owing to the introduction of high-density dislocations and deformation twins. Electrochemical measurements further showed that cold rolling enhanced corrosion resistance, with the charge transfer resistance increasing from 2.139 MΩ·cm 2 to 4.887 MΩ·cm 2 and 7.377 MΩ·cm 2 , while the corrosion current density decreased from 92.26 × 10 -7 A/cm 2 to 51.52 × 10 -7 A/cm 2 and 17.62 × 10 -7 A/cm 2 . These results demonstrate that cold rolling can effectively tailor martensitic morphology, texture evolution, and passive behavior in β-titanium alloys, thereby enabling an improved balance of low modulus, high strength, and corrosion resistance.