Electrochemical characteristics of the Al2Cu, Al3Ta and Al3Zr intermetallic phases and their relevancy to the localized corrosion of Al alloys

J. R. Scully, T. O. Knight, R. G. Buchheit, D. E. Peebles

Research output: Contribution to journalArticlepeer-review

139 Scopus citations

Abstract

The electrochemical behaviors of θ-Al2Cu phase, β-Al3Ta and, to a lesser extent, Al3Zr were compared to high purity Al in ambient temperature inert buffer solutions and, in certain cases, dilute halide solutions. The aim of this work is to develop a better understanding of electrochemical characteristics of these intermetallic phases. In particular, information was sought concerning (a) their galvanic couple relationship with respect to Al and (b) the relationship between the passive film formed on each phase and its ability to support both cathodic and anodic electron transfer reactions (ETR). The open circuit potentials (OCPs) of all three intermetallic phases were more positive than that of Al in inert solutions ranging from pH 2 to 12. The Al2Cu phase supports the reduction of water reaction at enhanced rates relative to pure Al due to the presence of metallic Cuo in an Al2O3 rich oxide but supports oxygen evolution due to a combination of this effect as well as formation of more electrically conductive copper oxides. A similar effect is observed for Al3Ta and is attributed mainly to the formation of a more conductive mixed oxide containing Ta2O5.

Original languageEnglish
Pages (from-to)185-195
Number of pages11
JournalCorrosion Science
Volume35
Issue number1-4
DOIs
StatePublished - 1993

ASJC Scopus subject areas

  • Chemistry (all)
  • Chemical Engineering (all)
  • Materials Science (all)

Fingerprint

Dive into the research topics of 'Electrochemical characteristics of the Al2Cu, Al3Ta and Al3Zr intermetallic phases and their relevancy to the localized corrosion of Al alloys'. Together they form a unique fingerprint.

Cite this