Corrosion resistance of nitrogen ion implanted titanium alloy for medical implants in physiological saline solution

A new titanium alloy for medical implants was implanted with nitrogen ions to improve corrosion resistance in physiological saline solution. The nitrogen ion implanted titanium showed marked changes in the corrosion resistance with various doses. Ti₂N was formed at lower dose and TiN was formed with increasing nitrogen dose. Corrosion potential shifted toward the noble direction and the passivation current density decreased by one order of magnitude with a dose of 2×10²¹ N₂⁺/m². No significant improvement was obtained with higher dose. Titanium alloy was implanted with nitrogen ions at multi-energy to obtain a homogeneous nitrogen concentration profile in the implanted layer. Corrosion resistance was improved by the multi-energy implantation