The Effect of Annealing Temperature and Immersion Time on the Active–Passive Dissolution of Biomedical Ti70Zr20Nb7.5Ta2.5 Alloy in Ringer’s Solution

Abstract

Because of their superior biocompatibility, chemical stability, and mechanical strength, Ti and Ti -based alloys are commonly utilized in orthopaedic dentistry. In Ringer ' s solution (RS), the corrosion behavior of the Ti 70 Zr 20 Nb 7.5 Ta 2.5 (T 70 Z 20 N 7.5 T 2.5 ) alloy was examined as an alternative potential material for Ti and Ti 6 Al 4 V (T 6 A 4 V) in medical applications. The corrosion resistance was evaluated utilizing potentiodynamic polarization curves (PPCs), electrochemical impedance spectroscopy (EIS), and open circuit potential techniques (OCP), supplemented by XRD and SEM surface analysis. The T 70 Z 20 N 7.5 T 2.5 alloy has the highest resistance to corrosion since it has the most stable passive state in addition to the lowest corrosion current (I corr ) and the highest corrosion potential (E corr ) in comparison with that of T 6 A 4 V and Ti. Furthermore, it was also looked at how different annealing temperatures (600, 800, and 1000 ºC)and immersion times (one, two, and three weeks) affected the corrosion behaviour of T 70 Z 20 N 7.5 T 2.5 . In comparison to the other samples, the T 70 Z 20 N 7.5 T 2.5 alloy annealed at 800 ºC demonstrated superior resistance to corrosion (the lowest I corr and I pass ). While that annealed at 1000 ºC has the lowest resistance to corrosion (highest I corr and I pass ) as a result of the passive layer dissolution. The same results are con rmed using the OCP measurements. The passive lm is composed of an inner and outer oxide layer, according to the EIS measurements. Meanwhile, the PPCs data demonstrates that the resistance to corrosion of the alloy is higher without immersion than it is with immersion and for a shorter immersion time. These results entirely agree with those of the EIS and OCP measurements of the alloy at the same immersion times. It was found that the T 70 Z 20 N 7.5 T 2.5 system consisted of α and β phases. An X-ray structural study indicated a mixture of body centred -cubic β-Ti and hexagonal close-packed α-Ti (main phase, with a grain size of about 5.35 nm). Therefore, among all the materials evaluated in this work, the T 70 Z 20 N 7.5 T 2.5 alloy can be considered a promising material suitable for use as a biomaterial.