Electrochemical Corrosion Investigation of Plasma Nitrided Ti-6Al-4V Alloy in Different Simulated Solution

Recently, researchers have progressively focused on the corrosion of biomedical implants and the leaching of metal ions into body fluids. To enhance the corrosion and wear resistance of metal implants, Titanium Nitride (TiN) coatings have been suggested as a viable option due to their high hardness and corrosion resistance. In the present study, TiN was formed on a Ti-6Al-4V alloy using the hollow cathode plasma nitriding process in N<inf>2</inf>-H<inf>2</inf> gaseous mixture at 800 °C for 8 h. The microstructural and structural properties of the TiN layer were characterized by scanning electron microscopy, x-ray diffraction, and x-ray photoelectron spectroscopy. To study the corrosion behavior of this alloy, potentiodynamic polarization and electrochemical impedance measurements were conducted in three different simulated solutions (3.5wt.% NaCl, Hank’s solution and artificial saliva). Electrochemical studies revealed that the plasma nitrided Ti-6Al-4V alloy exhibited superior corrosion resistance properties compared to the pristine Ti-6Al-4V alloy in all three simulated solutions. However, the corrosion resistance of both untreated Ti-6Al-4V and plasma nitrided Ti-6Al-4V alloy was found to be lower in artificial saliva solution compared to the other solutions. Additionally, the plasma nitrided Ti-6Al-4V alloy showed reduced metal ion release in the simulated solutions. Based on these findings, it can be concluded that the plasma nitrided Ti-6Al-4V alloy holds a great potential as an implant material in the medical field.