INIFTA   05425
INSTITUTO DE INVESTIGACIONES FISICO-QUIMICAS TEORICAS Y APLICADAS
Unidad Ejecutora - UE
artículos
Título:
CORROSION CRACK ENHANCEMENT DURING THE CATHODIC ACTIVATION OF ZIRCONIUM AB2 ALLOYS
Autor/es:
J. O. ZERBINO, A. VISINTIN, W. E. TRIACA.
Revista:
JOURNAL OF SOLID STATE ELECTROCHEMISTRY (PRINT)
Editorial:
Springer-Verlag GmbH
Referencias:
Año: 2006
ISSN:
1432-8488
Resumen:
The activation of zirconium nickel alloys with and without the addition of chromium and titanium is investigated through electrochemical and optical techniques. Recent investigations in aqueous 1 M KOH indicate oxide layer growth and occlusion of hydrogen species in the alloys during the application of different cathodic scan potential programmes currently used for the activation process. In this research several techniques such as voltammetry, ellipsometry, energy dispersive analysis of X-rays (EDAX) and scanning electron microscopy (SEM) are applied to three polished massive alloys, Zr1-xNix, x=0.36 and 0.43, and Zr0.9Ti0.1NiCr. Data analysis shows that the stability, compactness and structure of the passive layers are strongly dependent on the applied potential programme. The alloy activation depends on the formation of deep crevices that remain after further polishing. The microscopic observation shows an increase in crevice thickness after cathodic sweep potential cycling, which produces fragmentation of the grains and oxide growth during the activation process. This indicates metal breaking and intergranular alloy dissolution that take place together with oxide and hydride formation. In some cases the resultant crevice thickness is one or two orders higher than the growth of surface oxide indicating localised intergranular corrosion.