ELECTROCHEMICAL BEHAVIOUR OF FINEMET ALLOYS MODIFIED WITH BIG AMOUNTS OF COBALT

The electrochemical behaviour of three different Co-containing FINEMET alloys has been studied using cyclic voltammetry. In presence of big amounts of cobalt, oxidation processes are almost negligible at low anodic potentials. When the samples are submitted to termal relaxation and nanocrystallization processes, the oxidation charge decreases, probably due to the formation of a SiO₂ film on their surface. Polarization experiments show that the addition of Co shifts the corrosion potential anodically.