Deformation-induced changeable Young's modulus with high strength in 尾-type Ti-Cr-O alloys for spinal fixture

详细信息    查看全文

• 作者：Huihong Liu ; Mitsuo Niinomi ; Masaaki Nakai ; Junko Hieda ; Ken Cho
• 关键词：Ternary Ti&ndash ; Cr&ndash ; O alloys ; Changeable Young's modulus ; Athermal 蠅 phase ; Deformation-induced 蠅-phase transformation ; Springback
• 刊名：Journal of the Mechanical Behavior of Biomedical Materials
• 出版年：February, 2014
• 年：2014
• 卷：30
• 期：Complete
• 页码：205-213
• 全文大小：2119 K

文摘

In order to meet the requirements of the patients and surgeons simultaneously for spinal fixation applications, a novel biomedical alloy with a changeable Young's modulus, that is, with a low Young's modulus to prevent the stress-shielding effect for patients and a high Young's modulus to suppress springback for surgeons, was developed. In this study, the chromium and oxygen contents in ternary Ti(11, 12 mass%)Cr-(0.2, 0.4, 0.6 mass%)O alloys were optimized in order to achieve a changeable Young's modulus via deformation-induced 蠅-phase transformation with good mechanical properties.

The Young's moduli of all the examined alloys increase after cold rolling, which is attributed to the deformation-induced 蠅-phase transformation. This transformation is suppressed by oxygen but enhanced with lower chromium content, which is related to the 尾(bcc)-lattice stability. Among the examined alloys, the Ti-11Cr-0.2O alloy shows a low Young's modulus of less than 80 GPa in the solution-treated (ST) condition and a high Young's modulus of more than 90 GPa in the cold rolled (CR) condition. The Ti-11Cr-0.2O alloy also exhibits a high tensile strength, above 1000 MPa, with an acceptable elongation of ~12% in the ST condition. Furthermore, the Ti-11Cr-0.2O alloy exhibits minimal springback. This value of springback is the closest to that of Ti64 ELI alloy among the compared alloys. Therefore, the Ti-11Cr-0.2O alloy, which has a good balance between large changeable Young's modulus, high tensile strength, good plasticity, and minimal springback, is considered to be a potential candidate for spinal fixation applications.