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Author Straumanis, M. E. ♦ James, W. J. ♦ Custead, W. C.
Sponsorship USDOE
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword CHEMISTRY ♦ ANODES ♦ BEHAVIOR ♦ ELECTRIC POTENTIAL ♦ ELECTRODES ♦ FILMS ♦ HYDRIDES ♦ HYDROFLUORIC ACID ♦ HYDROGEN ♦ IONS ♦ PASSIVATION ♦ PLATINUM ♦ POLARIZATION ♦ SURFACES ♦ ZIRCONIUM
Abstract Zirconium dissolving in hydrofluoric acid exhibited a positive difference effect of such an efficiency that the hydrogen volume developed by the internal polarization current was completely overbalanced by the effect. As with other metals the effect was independent of the concentration of the acid and was accompanied by a strong shift in potential of the Zr electrode toward noble values (passivation). Similar potential changes were also recorded in presence of salts or more noble metals while they were displaced by the Zr. Simultaneously, the rate of dissolution of Zr dropped (nearly to zero with Pt/sup 4+/ additions). In the latter case the black hydride film on the surface disappeared and the Zr turned bright and shiny (passive Zr). A decrease in formation of the hydride film was observed in other cases of anodic polarization. The activity of Zr returned when the anodic current was cut off. As the effect of local currents due to anodic polarization is reduced to a minimum, the high rate of dissolution of Zr is explained by direct chemical action of Zr with molecular HF. (auth)
ISSN 00134651
Educational Use Research
Learning Resource Type Article
Publisher Date 1960-06-01
Publisher Department Univ. of Missouri, Rolla
Journal Journal of the Electrochemical Society
Volume Number 107
Organization Univ. of Missouri, Rolla


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