Electrochemical behavior of Ti-20Cr-X alloys in artificial saliva containing fluoride

Abstract

In this study, electrochemical investigation was carried out on commercially pure titanium (c.p. Ti) and as-cast Ti-20Cr-X (X = Nb, Mo, Fe, and Cr) in fluoride solutions containing artificial saliva. Open-circuit potential (OCP) and potentiodynamic polarization measurement were used to characterize the electrochemical behavior, and X-ray photoelectron spectroscopy (XPS) was used to characterize the composition of the passive films on the samples. The OCP results indicated that all specimens presented spontaneous passivation. XPS results showed that pre-test, a passive film consisting of TiO 2 and Cr 2 O 3 formed on the surface of the Ti-20Cr-X alloys, and Na 2 TiF 6 formed on the surface of all specimens after the polarization test in artificial saliva with 0.5 wt% NaF. Although the Ti-20Cr-X alloys exhibited a Na 2 TiF 6 film on their surface, their corrosion rate was still lower than that of c.p. Ti. In particular, Ti-20Cr-Mo alloy exhibited the lowest steady state current density compared to c.p. Ti and the other Ti-20Cr-X alloys. All these results suggest that the Ti-20Cr-X alloys hold promise for application as dental materials in a natural oral environment where NaF may be present.

Production and anodising of highly porous Ti–Ta–Zr–Co alloy for biomedical implant applications

“…Low pH and high F − values were lowered the corrosion potential and shifted up the corrosion current density. For a pH level, the stability of the oxide was lowered with rising F − concentration, due to the formation of defective surface oxide [29 -38]. Figure 5(c) clearly shows the effect of the Co addition on the potentiodynamic polarisation plots.…”

“…Chemical reagents purchased from Merck were employed for the artificial saliva preparation [27][28][29]. Amounts of the chemical reagents (g/L) for the 1L solution were 0.40 NaCl, 0.80 CaCl 2 , 0.40 KCl, 0.005 Na 2 S, 0.80 NaH 2 PO 4 , and 0.35 urea.…”

Characterisation of corrosion properties of Ti–Nb–Cu alloy foam by electrochemical impedance spectroscopy method

“…Artificial saliva solution was prepared from chemicals supplied by Merck, Germany. 4,[31][32][33] The amounts of the reagents were 0.40 g l 21 NaCl, 0.79 g l 21 CaCl 2 ?H 2 O, 0.40 g l 21 KCl, 0.005 g l 21 Na 2 S?9H 2 O, 0.78 g l 21 NaH 2 PO 4 ?H 2 O, and 0.35 g l 21 Urea-CO(NH 2 ) 2 . In an oral environment, in which pH varies between 2 and 11, F 2 concentration has effects on implants.…”

Corrosion of nonprecious metal alloys in dentistry in the presence of common saliva additives

“…[ 11‐15 ] Although nickel is frequently considered as being problematic because of its capability to cause allergic reactions, its use in such alloys has not been of noticeable concern after some changes of alloy composition resulted in significant improvements in their corrosion stability. [ 11 ] The relatively high corrosion stability of these alloys is certainly due to the passivation and formation of stable surface layers (for an example of such layers formed on chromium‐containing alloys, see Ho et al [ 16 ] ).…”