The Application of Electrochemical Methods to Characterize NiTi Corrosion and Nickel Elution

Currently, cyclic potentiodynamic polarization according to ASTM F2129 is widely used in the medical community to characterize corrosion behavior of small medical implants. In this paper, NiTi wire samples were prepared using several generic processing methods. Electrochemical characterization techniques including cyclic potentiodynamic polarization, linear polarization, and electrochemical impedance spectroscopy were used to characterize the corrosion behavior of the samples. Ni elution over time was characterized using Inductively coupled plasma mass spectrometry (ICP-MS). Phosphate Buffered Saline (PBS) solution at 37ºC was used for both Ni and corrosion characterizations. The applicability of electrochemical methods to predict Ni elution was discussed.