Young's modulus changeable β-type binary Ti-Cr alloys for spinal fixation applications

摘要

Presently metallic rods that are used for spinal fixtures cannot meet the requirements of both surgeons and patients; surgeons require the material to have a high Young's modulus to suppress springback during the operation, whereas patients require the material to have a low Young's modulus to prevent the stress-shielding effect. In order to develop a novel biomedical titanium alloy with a changeable Young's modulus for spinal fixation applications via deformation-induced ω phase transformation. The effects of deformation-induced phases on the mechanical properties of metastable β-type Ti-xCr alloys were investigated. The experimental results indicate that the Young's moduli, tensile strength, and Vickers hardness of the Ti-(10-12)Cr alloys increase remarkably by cold rolling. The results of the microstructural observations of Ti-12Cr alloys using a transmission electron microscopy (TEM) show that deformation-induced ω phase transformation occurs during cold rolling. Therefore, the increase in Young's modulus of the alloys is attributed to the deformation-induced ω phase, which is formed in the alloy during cold rolling at room temperature.