Department of Materials Science, Graduate School of Engineering, Tohoku University, Sendai, Japan.
Acta Biomater. 2012 Jul;8(6):2392-400. doi: 10.1016/j.actbio.2012.02.010. Epub 2012 Feb 15.
Metallic implant rods used in spinal fixtures should have a Young's modulus that is sufficiently low to prevent stress shielding for the patient and sufficiently high to suppress springback for the surgeon. Therefore, we propose a new concept: novel biomedical titanium alloys with a changeable Young's modulus via deformation-induced ω phase transformation. In this study, the Cr content in the range of 10-14 mass% was optimized to produce deformation-induced ω phase transformation, resulting in a large increase in the Young's modulus of binary Ti-Cr alloys. The springback and cytotoxicity of the optimized alloys were also examined. Ti-(10-12)Cr alloys exhibit an increase in Young's modulus owing to deformation-induced ω phase transformation. In this case, such deformation-induced ω phase transformation occurs along with {332}(β) mechanical twinning, resulting in the maintenance of acceptable ductility with relatively high strength. Among the examined alloys, the lowest Young's modulus and largest increase in Young's modulus are obtained from the Ti-12Cr alloy. This alloy exhibits smaller springback than and comparable cytocompatibility to the biomedical Ti alloy Ti-29Nb-13Ta-4.6Zr.
用于脊柱固定器的金属植入杆的杨氏模量应足够低，以防止患者的应力屏蔽，并且应足够高，以抑制外科医生的回弹。因此，我们提出了一个新概念：通过变形诱导ω相转变，具有可变化学杨氏模量的新型生物医用钛合金。在这项研究中，优化了 10-14 质量%范围内的 Cr 含量以产生变形诱导的ω相转变，从而使二元 Ti-Cr 合金的杨氏模量大大增加。还研究了优化合金的回弹和细胞毒性。Ti-(10-12)Cr 合金由于变形诱导的ω相转变而表现出杨氏模量的增加。在这种情况下，这种变形诱导的ω相转变伴随着{332}(β)机械孪晶的产生，从而在保持相对高强度的同时保持可接受的延展性。在所检查的合金中，最低的杨氏模量和最大的杨氏模量增加是从 Ti-12Cr 合金获得的。与生物医学钛合金 Ti-29Nb-13Ta-4.6Zr 相比，该合金的回弹较小，细胞相容性相当。
