Electrochemical behavior and localized corrosion associated with Al7Cu2Fe particles in aluminum alloy 7075-T651

Initiation of localized corrosion upon high strength aluminum alloys is often associated with cathodic intermetallic particles within the alloy. Electrochemical measurements and metallurgical characterization have been made to clarify and quantify the physical properties of Al7Cu2Fe particles in AA7...

Full description

Saved in:
Bibliographic Details
Published in:Corrosion science 2006-12, Vol.48 (12), p.4202-4215
Main Authors: BIRBILIS, N, CAVANAUGH, M. K, BUCHHEIT, R. G
Format: Article
Language:English
Subjects:
Applied sciences
Corrosion
Corrosion environments
Exact sciences and technology
Metals. Metallurgy
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Initiation of localized corrosion upon high strength aluminum alloys is often associated with cathodic intermetallic particles within the alloy. Electrochemical measurements and metallurgical characterization have been made to clarify and quantify the physical properties of Al7Cu2Fe particles in AA7075-T651. Prior studies regarding either the stereology or electrochemical properties of Al7Cu2Fe are scarce. Quantitative microscopy revealed a significant population of Al7Cu2aFe in the alloy; comprising up to 65% of the constituent particle population and typically at a size of 1.7 plus/minus 1.0 mum. It was determined that Al7Cu2Fe may serve as a local cathode in the evolution of localized corrosion of AA7075-T651 and is capable of sustaining oxygen reduction reactions at rates of several hundreds of muA/cm2 over a range of potentials typical of the open circuit potential (OCP) of AA7075-T651 in NaCl solution of various concentrations and pH. The presence of Al7Cu2Fe leads to the development of pitting at the particle-matrix interface.
ISSN:0010-938X
1879-0496
DOI:10.1016/j.corsci.2006.02.007