Fabrication and mechanical properties of Bi-added Ti-Cr alloys for biomedical applications
Fabrication and mechanical properties of Bi-added Ti-Cr alloys for biomedical applications
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DOI：
10.1016/j.jmrt.2023.02.173
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发表时间：
2023-02
期刊：
影响因子：
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通讯作者：
N. Nohira;K. Hayashi;M. Tahara;H. Hosoda
中科院分区：
文献类型：
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作者：
N. Nohira;K. Hayashi;M. Tahara;H. Hosoda
从力学性能和相稳定性的角度评价了添加铋（Bi）对开发生物相容性亚稳β（bcc）钛合金的潜力。基础合金为Ti-5mol%Cr，并在标称成分中添加0- 9mol%Bi。还选择了Ti-Bi二元合金。使用标准实验室规模的电弧熔化机在Ar气氛下制造合金。由于Bi蒸发，在熔融期间重量损失显著。测得的Bi含量与Bi的名义成分成线性关系，MCBi = 2/3 NCBi，允许预测和控制合金的Bi含量。然后，系统地研究了显微组织、加工性能和力学性能。Ti-5Cr二元合金的相组成为β + α′（hcp）+ ω（六方）。非热ω相的存在导致显著差的冷加工性和差的延展性。Bi对Ti-5Cr合金中β相的形成起到了稳定作用，抑制了ω相的形成。用Mo当量和电子原子比（e/a）讨论了Ti-Cr-Bi合金的相稳定性。Ti-5Cr-1.6Bi合金具有良好的加工性能和塑性。随着Bi添加量的增加，Ti-5Cr-3.7Bi合金没有发生塑性变形，Ti-5Cr-6.1Bi合金甚至在热轧过程中发生断裂。因此，可以得出结论，0.2mol %的Bi添加是合适的，并且如此少量的Bi添加是开发β Ti合金的有吸引力的候选者。
The potential of the Bismuth (Bi) addition was evaluated for the development of biocompatible metastable β (bcc) Ti alloys from the viewpoints of mechanical properties and phase stability. The basic alloy was Ti–5 mol% Cr, and 0–9 mol% Bi was added in nominal composition. A Ti–Bi binary alloy was also selected. The alloys were fabricated using a standard laboratory-scale arc melting machine under an Ar atmosphere. The weight loss was significant during melting due to Bi evaporation. The measured Bi content is linearly proportional to the Bi nominal composition withMCBi= 2/3NCBi, allowing the prediction and control of Bi content of the alloy. Then, the microstructure, workability, and mechanical properties were systematically investigated. The phase constitution of the Ti–5Cr binary alloy was β + α′ (hcp) + ω (hexagonal). The presence of the athermal ω phase resulted in significantly poor cold workability and poor ductility. It was also found that the addition of Bi to the Ti–5Cr alloy stabilized the β phase and suppressed the ω phase formation. The phase stability of Ti–Cr–Bi alloy is discussed using Mo equivalent and electron-to-atom (e/a) ratio. Ti–5Cr–1.6Bi alloy showed improved workability and ductility. However, with further increasing Bi addition, the Ti–5Cr–3.7Bi alloy showed no plastic deformation, and the Ti–5Cr–6.1Bi alloy was broken even during hot-rolling. Thus, it is concluded that ∼2 mol% Bi addition is suitable and that such a small amount of Bi addition is an attractive candidate for the development of β Ti alloys.