Analysis of ohmic effects in passivation processes

V. BRUNETTI; H. M. VILLULLAS; M. LÓPEZ TEIJELO

MATERIALS SCIENCE FORUM

Año: 1998 p. 829 - 829

0255-5476

p style="text-align: justify;" class="MsoNormal">The active-pasive transition of silver electrodes in solutions containing sulphate or chromate is described. The formation of the silver salt layer takes place through a dissolution-precipitation mechanism. The early stages of growth of the Ag2CrO4 films involve a three dimensional nucleation process with growth controlled by diffusion of chromate ions. The overall rate of salt films growth in both electrolytes is controlled by the resistance of the electrolyte in the pores of the layer. Experimental data are compared with calculated curves for the layer-pore resistance model.