Fatigue performance and cyto-toxicity of low rigidity titanium alloy, Ti-29Nb-13Ta-4.6Zr.

A beta type titanium alloy, Ti-29Nb-13Ta-4.6Zr, was newly designed and developed for biomedical applications. The new alloy contains non-toxic elements such as Nb, Ta, and Zr. In the present study, phases that appeared in the new alloy through various aging treatments were characterized by hardness tests and microstructural observations in order to identify the phase transformation. Fatigue properties of the new alloy were investigated. Young's modulus and cyto-toxicity of the new alloy were also evaluated. Precipitated phases distribute homogeneously over the whole specimen, and they are alpha phase, a small amount of omega phase, and beta phase when the new alloys are subjected to aging treatment at 673K for 259.2ks after solution treatment at 1063K for 3.6ks. The fatigue strength of the new alloy subjected to aging at 673K for 259.2ks after solution treatment at 1063K for 3.6ks is much better than when subjected to other aging treatments. In this case, the fatigue limit is around 700MPa. Young's modulus of the new alloy is much smaller than that of Ti-6Al-4V ELI. The cyto-toxicity of the new alloy is equivalent to that of pure Ti. Therefore, it is proposed that the new alloy, Ti-29Nb-13Ta-4.6Zr, will be of considerable use in biomedical applications.

[1]  K. S. Ravichandran,et al.  Effect of mean stress (stress ratio) and aging on fatigue-crack growth in a metastable beta titanium alloy, Ti-10V-2Fe-3Al , 2000 .

[2]  M. Niinomi,et al.  Corrosion wear fracture of new β type biomedical titanium alloys , 1999 .

[3]  G. Winter,et al.  Evaluation of biomaterials , 1980 .

[4]  T. Mosmann.  Rapid colorimetric assay for cellular growth and survival: application to proliferation and cytotoxicity assays. , 1983, Journal of immunological methods.

[5]  M. Niinomi,et al.  An investigation of the effect of fatigue deformation on the residual mechanical properties of Ti-6Al-4V ELI , 2000 .

[6]  O. Umezawa,et al.  Distribution of Internal Crack Initiation Sites in High-cycle Fatigue for Titanium Alloys , 1997 .

[7]  M. Niinomi,et al.  Effects of microstructure on the short fatigue crack initiation and propagation characteristics of biomedical α/β titanium alloys , 2000 .

[8]  M. Niinomi,et al.  Design and mechanical properties of new β type titanium alloys for implant materials , 1998 .

[9]  E Borenfreund,et al.  Toxicity determined in vitro by morphological alterations and neutral red absorption. , 1985, Toxicology letters.

[10]  M. Hagiwara.  Fatigue Mechanism of Titanium Alloys. , 1998 .

[11]  S. G. Steinemann,et al.  Corrosion of Surgical Implants-in vivo and in vitro Tests , 1980 .

[12]  Wolfgang Bunk,et al.  Deformation modes of the α-phase of ti-6al-4v as a function of oxygen concentration and aging temperature , 1982 .

[13]  Mitsuo Niinomi,et al.  Recent metallic materials for biomedical applications , 2002 .

[14]  Mean stress sensitivity in fatigue of α, (αβ) and β titanium alloys , 1997 .

[15]  J. Davidson,et al.  Mechanical and Tribological Properties and Biocompatibility of Diffusion Hardened Ti-13Nb-13Zr — A New Titanium Alloy for Surgical Implants , 1996 .

[16]  M. Ozawa,et al.  Application of Piezoelectric Composite-Bar Method to Elastic Modulus Measurement of Ceramics (Part 1) , 1990 .

[17]  K. Shiozawa,et al.  Effect of Stress Ratio on Subsurface Fatigue Crack Initiation Behavior of Beta-Type Titanium Alloy. , 1998 .

[18]  R. Boyer,et al.  Fatigue behavior of titanium alloys , 1999 .