Document Type

Article

Research Focus Area

Advanced and Nanostructured Materials

Publication Date

2004

Journal or Book Title

Journal of the Electrochemical Society

Volume

151

Issue

6

First Page

B340

Last Page

B346

DOI

10.1149/1.1715091

Abstract

A model for pit initiation during galvanostatic anodic etching of aluminum in acid chloride-containing solutions was developed. The predictions were compared to experimental potential transients and pit-size distributions. The model presumed that pits initiated from subsurface nanoscale voids, which were exposed by uniform corrosion. Void concentrations fit from potential transients depended on times of caustic and acid exposure before etching, in agreement with prior characterization of the voids by positron annihilation measurements. The model yielded realistic predictions of the effect of applied current density and temperature on the potential transients. The effective void concentration was found to increase with the chloride concentration in the etching solution; this suggested that higher chloride concentrations inhibit passivation of newly exposed voids, enhancing their survival probability. On the whole, the interfacial void model provided a promising quantitative description of pit initiation during anodic etching.

Comments

This article is from Journal of the Electrochemical Society 151 (2004): B340–B346, doi:10.1149/1.1715091.

Copyright Owner

ECS—The Electrochemical Society

Language

en

File Format

application/pdf

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