Enhancement of Mechanical Biocompatibility of Titanium Alloys by Deformation-Induced Transformation

Abstract:

Metastable β-type titanium alloys are highly suitable for use as structural biomaterials applied to hard tissue, i.e., as cortical bone (hereafter, bone) replacing implants. However, their mechanical biocompatibitities, such as the Young’s modulus, strength and ductility balance, fatigue strength, resistance against fatigue crack propagation and fracture toughness, require improvenent for increased compatibility with bone. Through deformation, the metastable β-phase in a metastable β-type titanium alloy is transformed into various phases, such as α’ martensite, α” martensite, and ω-phases with exact phase depending by metastable β-phase stability. In addition, twinning is also induced by deformation. Deformation twinning effectively enhances the work hardening in the metastable β-type titanium alloy, leading to increased strength and ductility. This improvement is accompanied by with other deformation-induced transformations including the appearance of deformation-induced martensite and ω-phase transformation. The enhancement of the mechanical biocompatibility of various materials using the abovementioned deformation-induced transformation is described in this paper, for both newly developed metastable β-type Ti-Mo and Ti-Cr alloys for biomedical applications.

• Periodical: Materials Science Forum (Volume 879)
• Pages: 125-130
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.879.125
• Online since: November 2016
• Authors: Mitsuo Niinomi*
• Keywords: Deformation-Induced ω-Phase, Meta Stable β-Phase, Ti-6Al-4V, Ti-Cr System Alloys, Ti-Mo System Alloys, TRIP, TWIP, Young’s Modulus Self-Adjustable Titanium Alloys

References

[1] M. Nakai, M. Niinomi, X. F. Zhao and X. L. Zhao, Self-adjustment of Young's modulus in biomedical titanium alloys during orthopaedic operation, Mater. Letters, 65(2011) 688–90.

DOI: 10.1016/j.matlet.2010.11.006

[2] M. Niinomi, M. Nakai and J. Hieda: Development of new metallic alloys for biomedical applications, Acta Biomaterialia, 8(2012) 3888-3903.

DOI: 10.1016/j.actbio.2012.06.037

[3] X.F. Zhao, M. Niinomi, M. Nakai and J. Hieda, Optimization of Cr content of metastable β-type Ti-Cr alloys with changeable Young's modulus for spinal fixation applications, Acta Biomaterialia, 8(2012), 2392- 2400.

DOI: 10.1016/j.actbio.2012.02.010

[4] X. Zhao, M. Niinomi, M. Nakai and J. Hieda, Beta type Ti–Mo alloys with changeable Young's modulus for spinal fixation applications, Acta Matelialia, 8 (2012) 1990–(1997).

DOI: 10.1016/j.actbio.2012.02.004

[5] S. Hanada and O. Izumi, Deformation behavior of retained b phase in b-eutectoid Ti-Cr alloys, J Mater. Sci., 21(1986) 4131–4139.

DOI: 10.1007/bf01106518

[6] S. Hanada and O. Izumi, Correlation of tensile properties, deformation modes, and phase stability in commercial b-phase titanium alloys, Metall. Trans. A, 18(1987) 265–271.

DOI: 10.1007/bf02825707

[7] T. S. Kuan, R. R. Ahrens and S. I. Sass, The stress-induced omega phase transformation in Ti–V alloys, Metall. Trans. A, 6(1975) 1767–1774.

DOI: 10.1007/bf02642306

[8] M. Oka and Y. Taniguchi, Deformation twins in a Ti–155 pct V alloy. Metall. Trans. A, 10(1979) 651–653.

DOI: 10.1007/bf02658330

[9] H. Matsumoto H. Watanabe, N. Masahashi and S. Handa, Composition dependence of Young's modulus in Ti–V, Ti–Nb, and Ti–V–Sn alloys, Metall. Trans. A, 37(2006) 3239–3249.

DOI: 10.1007/bf02586159

[10] S. Hanada and O. Izumi, Transmission electron microscopic observations of mechanical twinning in metastable beta titanium alloys, Metall. Trans. A, 17(1986) 1409–1420.

DOI: 10.1007/bf02650122

[11] S. Hanada, T. Yoshio and O. Izumi, Plastic deformation mode of retained b phase in b-eutectoid Ti-Fe alloys, J. Mater. Sci., 21 (1986) 866-870.

DOI: 10.1007/bf01117366

[12] F. Sun, J.Y. Zhang, M. Marteleur, T. Gloriant, P. Vermaut, D. Laille´, P. Castany, C. Curfs, P.J. Jacques, F. Prima, Investigation of early stage deformation mechanisms in a metastable b titanium alloy showing combined twinning-induced plasticity and transformation-induced plasticity effects, Acta Materialia, 61(2013).

DOI: 10.1016/j.actamat.2013.07.019

[13] H. H. Liu, M. Niinomi, M. Nakai, J. Hieda and K. Cho, Changeable Young's modulus with large elongation-to-failure in b-type titanium alloys for spinal fixation applications, Scripta Materialia, 82(2014) 29-32.

DOI: 10.1016/j.scriptamat.2014.03.014

[14] M. Niinomi, M, Nakai and J, Hieda, Development of new metallic alloys for biomedical applications, Acta Biomaterialia, 8(2012) 3888-3903.

DOI: 10.1016/j.actbio.2012.06.037

[15] X.H. Min, X.J. Chen, S. Emura, K. Tsuchiya, Mechanism of twinning-induced plasticity in b-type Ti–15Mo alloy, Scr. Mater., 69 (2013) 393-396.

DOI: 10.1016/j.scriptamat.2013.05.027