Electrochemical behaviour of Ti–25Nb–3Mo–3Zr–2Sn biomedical alloy in different simulated physiological environments

Abstract

The electrochemical corrosion behaviour of biomedical Ti-25Nb-3Mo-3Zr-2Sn (TLM) alloy was investigated in various simulated body fluids at 37¡0?5uC utilising potentiodynamic polarisation and current-time curves. The Ti-6Al-4V (TC4) alloy was also investigated to make a comparison. The different simulated body fluids comprised of 0?9%NaCl saline, Hank's and Ringer's solution were employed. The effect of heat treatment on the electrochemical behaviour of the TLM alloy was also considered. It was discovered that all the test specimens were passivated once immersed into the simulated body fluids. It was also found that the TLM alloy has poorer corrosion resistance in Hank's solution, due to the chemical composition of the Hank's. After different heat treated, the TLM alloy had different phases and microstructure, and the corrosion behaviour of the TLM alloy was different. In this study, after the heat treatment of 760uC/1 h/ACz550uC/6 h/AC, the TLM alloy had better corrosion resistance. Owing to the corrosion resistance of the TLM alloy was influenced by numerous factors, such as microstructure and the chemical composition of electrolyte, the corrosion behaviour of the TLM alloy is complex. By comparing with the corrosion behaviour of the TC4 alloy, the TLM alloy has poorer corrosion resistant than the TC4 alloy under the same conditions. But the current-time curves of the TLM alloy were more stable than these of the TC4 alloy with further experiments, because of the more passivation film on the surface of the TLM alloy.

Tribocorrosion behavior of NiTi alloy as orthopedic implants in Ringer’s simulated body fluid

“…Tribocorrosion experiment tests were carried out using a ball-on-disk wear tester (TE66, UK) connected to a potentiostat (Gamry interface 1000, USA), which was similar to the device reported in [11,12]. The Ringer's simulated body fluid was used as the electrolyte during the tests [18]. The counterpart was a ZrO 2 ceramic ball of 25.4 mm in diameter.…”

Comparison of the Microstructure and Biocorrosion Properties of Additively Manufactured and Conventionally Fabricated near β Ti–25Nb–3Zr–3Mo–2Sn Alloy

“…This is evident from the (i) higher i corr , (ii) higher i p , and (iii) lower impedance, and (iv) lower PR values observed for the TLM alloys, and is consistent with the previously published work. 47,51 It is known that alloying elements can alter the corrosion resistance of Ti. For example, Nb and Ta are known to improve the corrosion resistance of β Ti alloys.…”

“…It is possible that the presence of second phases in TLM-3D and TLM-UG induced galvanic microcells to form and increase the corrosion behavior of the metal. Wang et al 51 noted significant reduction in the corrosion resistance of Ti− 25Nb−3Mo−3Zr−2Sn after annealing due to the enlargement of the secondary α phase. Their conclusion is that the corrosion resistance of TLM alloys is influenced not only by alloy composition but also by microstructural features such as the number of phases, phase composition, and phase morphology.…”

“…Yu et al 50 reported a slight improvement in passivity (i.e., larger passivation region with lower passivation current) in Tyrode's solution after micro-arc oxidation treatment of the TLM. Wang et al 51 studied the electrochemical corrosion behavior of TLM in different physiological fluids. They observed that TLM showed the highest corrosion rate in Hanks' solution compared to Ringer's and 0.9% saline solutions.…”