Improving the Mechanical Properties of a β-type Ti-Nb-Zr-Fe-O Alloy

Abstract

The influence of complex thermo-mechanical processing (TMP) on the mechanical properties of a Ti-Nb-Zr-Fe-O bio-alloy was investigated in this study. The proposed TMP program involves a schema featuring a series of severe plastic deformation (SPD) and solution treatment (STs). The purpose of this study was to find the proper parameter combination for the applied TMP and thus enhance the mechanical strength and diminish the Young’s modulus. The proposed chemical composition of the studied β-type Ti-alloy was conceived from already-appreciated Ti-Nb-Ta-Zr alloys with high β-stability by replacing the expensive Ta with more accessible Fe and O. These chemical additions are expected to better enhance β-stability and thus avoid the generation of ω, α’, and α” during complex TMP, as well as allow for the processing of a single bcc β-phase with significant grain diminution, increased mechanical strength, and a low elasticity value/Young’s modulus. The proposed TMP program considers two research directions of TMP experiments. For comparisons using structural and mechanical perspectives, the two categories of the experimental samples were analyzed using SEM microscopy and a series of tensile tests. The comparison also included some already published results for similar alloys. The analysis revealed the advantages and disadvantages for all compared categories, with the conclusions highlighting that the studied alloys are suitable for expanding the database of possible β-Ti bio-alloys that could be used depending on the specific requirements of different biomedical implant applications.

Biological Safety Evaluation and Surface Modification of Biocompatible Ti–15Zr–4Nb Alloy

“…An evaluation of osseointegration using similar bone morphometrical parameters as in this study has been previously performed [ 49 ]. These results support those of material development of Ti alloys to which Zr, Nb, and Ta have been added [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ].…”

“… New bone formation rate ( a ), bone contact rate ( b ), and new bone thickness ( c ) for Ti–Ni, Ti–15–3–3, Ti–6–4 [ 16 ], and Ti–15–4–4 [ 16 ]. …”

“…The adverse effects of metal ions include the cytotoxicity of trace amounts of vanadium (V) and aluminum (Al) ions in Ti–6Al–4V alloy and the allergy-related characteristics of nickel (Ni) ions [ 2 , 3 , 4 ]. Recently, many types of Ti alloy containing noncytotoxic elements such as zirconium (Zr), niobium (Nb), tantalum (Ta), and molybdenum (Mo) have been developed for various medical applications [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ]. Ti–15Zr–4Nb–(0 to 4) Ta alloy, which is an alpha (α)–beta (β)-type alloy, has been developed in Japan as a highly biocompatible alloy [ 17 ], and it is standardized in JIS T 7401-4 [ 18 ].…”

Titanium Alloys and Titanium-Based Matrix Composites

“…Ti-15Mo alloy was subjected to two techniques of intensive plastic deformation-high-pressure torsion and rotary swaging at room temperature-leading to the formation of an ultrafine-grained microstructure. It was found that, after isothermal ageing in both deformed conditions, precipitations of the α phase remain small and equiaxed even after ageing at 500 • C for 16 h. The other β alloy-Ti-Nb-Zr-Fe-O-was investigated by Cojocaru et al [7]. The influence of complex thermo-mechanical processing on its mechanical properties was analyzed.…”

Ultrafine-Grained Ti-31Mo-Type Composites with HA and Ag, Ta2O5 or CeO2 Addition for Implant Applications

“…The aim of the current study is directed at improving the physicochemical and mechanical properties as well as biocompatibility of Ti-based systems through crystal structure evolution (α → β) and new microstructure formation (micro → nano or ultrafine) via its chemical composition modification and processing method, respectively [ 4 , 5 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ]. β-type titanium alloys are interesting biomaterials for innovative implantable medical devices.…”