Graduate Student, Department of Materials Science, Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan.
Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan.
J Mech Behav Biomed Mater. 2014 Feb;30:205-13. doi: 10.1016/j.jmbbm.2013.11.001. Epub 2013 Nov 15.
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 ω-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 ω-phase transformation. This transformation is suppressed by oxygen but enhanced with lower chromium content, which is related to the β(bcc)-lattice stability. Among the examined alloys, the Ti-11Cr-0.2O alloy shows a low Young's modulus of less than 80GPa in the solution-treated (ST) condition and a high Young's modulus of more than 90GPa in the cold rolled (CR) condition. The Ti-11Cr-0.2O alloy also exhibits a high tensile strength, above 1000MPa, 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.
为了同时满足患者和外科医生对脊柱固定应用的要求，开发了一种具有可变化学模量的新型生物医学合金，即具有较低的杨氏模量以防止患者的应力屏蔽效应，以及较高的杨氏模量以抑制外科医生的回弹。在这项研究中，优化了三元 Ti(11,12wt%)Cr-(0.2,0.4,0.6wt%)O 合金中的铬和氧含量，以通过具有良好力学性能的变形诱导 ω 相转变来实现可变化学模量。所有研究合金的杨氏模量在冷轧后都会增加，这归因于变形诱导的 ω 相转变。这种转变受氧的抑制但随铬含量降低而增强，这与 β(bcc)-晶格稳定性有关。在所研究的合金中，Ti-11Cr-0.2O 合金在固溶处理 (ST) 条件下表现出低于 80GPa 的低杨氏模量，在冷轧 (CR) 条件下表现出高于 90GPa 的高杨氏模量。Ti-11Cr-0.2O 合金还表现出 1000MPa 以上的高强度，在 ST 条件下具有可接受的 12%左右的伸长率。此外，Ti-11Cr-0.2O 合金表现出最小的回弹。与比较的合金相比，这种回弹值最接近 Ti64 ELI 合金。因此，Ti-11Cr-0.2O 合金具有较大的可变化学模量、高强度、良好的塑性和最小的回弹之间的良好平衡，被认为是脊柱固定应用的潜在候选材料。
