Effect of Long-term Immersion on the Pitting Corrosion Resistance of Nitinol

One of the challenges faced by medical-device manufacturers is the use of short-term in-vitro data to evaluate the long-term in-vivo corrosion performance of implants. In this study, mechanically polished Nitinol wires were immersed in phosphate-buffered saline (PBS) at 37 °C for up to one week prior to performing cyclic polarization tests. Results are presented that show the effect of immersion time on rest potentials and breakdown potentials, and hence the resistance to pitting corrosion.