The multiphase alloy MP35N, composed of 35% nickel, 35% cobalt, 20% chromium, and 10% molybdenum, is widely used in implantable medical devices. Samples were electropolished, passivated, and analyzed with DC potentiostatic cyclic polarization scans. All samples were electropolished similarly, divided into eight groups, and passivated according to the necessary conditions. These conditions investigated the impact of passivation time, temperature, and solution on the electrochemical characteristics of the samples. In all, 32 trials were completed (n = 4), and results were analyzed by design of experiments software. Passivation conditions were either 10 or 60 minutes, temperature was either 25 or 65 �C, and the solution used for passivation was either 35% nitric acid or 4% citric acid. When passivated for 60 minutes using a 65 �C nitric acid solution, the cyclic polarization scans indicated that no breakdown occurred.

Comparison of passivation techniques on Multiphase® alloy (35% Ni)

245th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.