Derivation of Anodic Dissolution Curve Of Alloys from those of Metallic Components

The Anodic Dissolution of Binary Alloys

“…Finally when the dispersion reaches atomic dimensions, a solid solution, surface enrichment controls the dissolution rate of the alloy. By considering surface enrichment as the rate-determining factor, Mueller (21) has derived an expression for the steady-state dissolution rate of a homogeneous alloy. A slight modification of this derivation follows:…”

“…[9] will fail for certain homogeneous alloys. Mueller (21) has pointed out that deviations are more likely when an alloy contains an excess of the active component. The principle underlying Eq.…”

“…Mueller (21) has suggested that the formation of mixed oxides or spinels may lead to passive films on alloys which are less soluble than those of either component. Such reactions also could explain the observed differences.…”

The Influence of Film Thickness on the Thermodynamic Properties of Thin Oxide Layers on Iron

“…Whatever the mechanistic source of the Flade potential may be, its dependence on the hydrogen-ion concentration and the rapid response of the potential of a passivated electrode to changes in acidity demonstrate that some kind of proton interaction is involved at the interface. In several instances, it has been shown (11)(12)(13)(14) that partial oxidation of a solid M(OH)2 consists of the mere loss of a proton and an electron without change of structure. These facts make it probable that protons need to be considered as essential components of the passive film and as participants in any electrochemical processes at the surface.…”

Anodische Polarisationskurven von Messinglegierungen in Ammoniumchloridlösungen

“…Berechnung der Aquivalente der Kupferionen aus der durch die Legierung bis zur Passivierungszeit gegangenen Ladung Komponente der Legierung ist, kann die Ableitung des anodischen Verhaltens der Legiemngen vom anodischen Verhalten des Kupfers versucht werden.Versuche, die Polarisationskurven von Legierungen als Funktion der Polarisationskurven der in der Legierung enthaltenen reinen Metalle auszudrucken, sind bereits durchgefuhrt worden(10)(11)(12)(13). Nehmen wir an, da8 die Bildung der CuC1-Schicht erst nach Uberschreitung des Loslichkeitskoeffizienten von CuC12-beginnt und d a 8 die Stromabnahme auf die Entstehung der Schicht zuriickzufuhren ist, die die Oberflache der Legierung teilweise isoliert.…”