Abstract

ROCHA, Jaime A; TERRAZAS, Rodrigo D  and  PRADA, Gabriela. Electrochemical evaluation of alloys with high corrosion resistance: Nitinol for cardiac implants. Rev. Met. UTO [online]. 2015, n.36, pp. 19-25. ISSN 2078-5593.

One of the major advances in medicine is the use of alloys with appropriate mechanical properties, mainly biocompatibility and high resistance to corrosion. This is the case of Nitinol, an alloy which was discovered in the laboratories of the US Navy. In Bolivia, PFM S.R.L., since a long time ago, has been manufacturing and exporting medical devices such as NotOccludASD-R, it's used to close the abnormal communication between the atria of the heart using the technique called cardiac catheterization. The present paper describes the procedure to verify the resistance to corrosion of medical devices, whenever changes occur in composition, heat treatment or design. Using the polarization curves and the impedance spectra, the results obtained for samples of Nitinol with heat treatment of nitruration at different times showed that, despite of effects associated to then nitruration time, the devices have "rupture potentials" above the oxidation levels accepted by the FDA, USA (approximately 600 mV/ ENH).

Keywords : Biocompatible alloys; corrosion; Nitinol; stents.