The Open Corrosion Journal

2010, 3 : 45-53
Published online 2010 June 02. DOI: 10.2174/1876503301003010045
Publisher ID: TOCORRJ-3-45

Electrochemical Determination of the Corrosion Resistance of NiCr Dental Casting Alloys

D. Mareci , A. Cailean , G. Ciurescu and D. Sutiman
Technical University “Gh. Asachi” Iasi, Faculty of Chemical Engineering and Environmental Protection, Bd. D. Mangeron, No. 71, Area code 700050, Iasi, Romania

ABSTRACT

Based on the polarization curves and electrochemical impedance spectroscopy (EIS) in the case of four commercial dental alloys (Wirolloy, Heraenium, NicromalSoft and VeraSoft) maintained in 0.1M NaCl solution, it was established the type and the intensity of the corrosion process by means of the corrosion currents value. The passivation of all the samples occurred spontaneously at the open circuit potential. The corrosion currents value decrease after the alloys maintenance in the corrosive medium due their passivation. The corrosion currents have values of nA order for all the samples and decrease with the increase of the immersion time. The alloys Heraenium and Wirolloy are in the optimum corrosion resistant condition. The VeraSoft and NicromalSoft alloys presented a dangerous breakdown potential (about 200-300 mV). The EIS results show that all NiCr-based alloys exhibits passivity at open circuit potential. The Heraenium and Wirolloy alloys with dendritic microstructure show the best electrochemical behaviour in 0.1M NaCl solutions.

Keywords:

NiCr dental alloys, open circuit potential, corrosion current, potentiodynamic polarisation curves, EIS.