A Soft X-Ray Study of the Near Surface Composition of Cu30Zn Alloy during Simultaneous Dissolution of Its Components

Publisher Website
Google Scholar
Abstract
For certain conditions, alloys composed of metals of different nobility anodically dissolve without noticeable preferential dissolution of the less noble metal (simultaneous dissolution). In principle, an induction period of disproportionate dissolution of the less noble metal should precede simultaneous (nonselective) dissolution. In the present paper, the existence of the induction period is demonstrated by soft x‐ray spectroscopy of the alloy surface. Results are presented for anodically polarized Cu‐30 atomic per cent Zn in an acidic sulfate solution. Analyses of the Cu LII,III Zn LII,III, and oxygen K band spectra of these specimens for several accelerating voltages (corresponding to different depths into the alloy ranging up from 102Aå) show that the amount of elemental copper in the surface layer increases during an initial period of dissolution. It is concluded that Cu‐enrichment of the surface is a necessary condition for simultaneous dissolution of the alloy. A model of simultaneous dissolution is presented which incorporates Cu‐enrichment and a diffusion field in a shallow, alloy layer at the surface.

This publication has 0 references indexed in Scilit: