The role of precipitates upon the electrochemical stability of aluminium

X. Zhou, D. D. Macdonald, J. H. Xia, G. Sha, S. P. Ringer, N. Birbilis

Research output: Chapter in Book/Report/Conference proceedingConference PaperResearchpeer-review

Abstract

Whilst the electrochemical stability of a metal is typically described in terms of equilibrium thermodynamics, in an engineering context, a likelihood of corrosion as predicted by thermodynamics is not as useful as knowing the kinetic response (i.e. how fast a metal reacts in a certain environment). This work presents a discrete effort towards developing an improved understanding and representation of kinetic stability for aluminium-based metals, as an engineering alternative to Pourbaix diagrams. The overall study will assess the environmental envelope for passivity of aluminium, and account for the influence of microstructural heterogeneities (grain size, precipitates and crystallinity), which are not presently considered in equilibrium thermodynamics. In prior work we presented kinetic stability diagrams for pure aluminium with different grain size and grain boundary density. In the present study, we convey preliminary kinetic stability diagrams as a function of pH and potential for Al-4wt%Cu alloys with different precipitate size distribution and density - to elucidate the effect of precipitate state upon electrochemical kinetics.

Original languageEnglish
Title of host publicationAnnual Conference of the Australasian Corrosion Association 2012
Subtitle of host publicationMelbourne, Victoria, Australia; 11-14 November 2012
Place of PublicationKerrimuir VIC Australia
PublisherAustralasian Corrosion Association
Pages472-478
Number of pages7
ISBN (Print)9781622769698
Publication statusPublished - 2012
EventAustralasian Corrosion Association (ACA) Conference 2012: Corrosion and Prevention - Crown Conference Centre, Melbourne, Australia
Duration: 11 Nov 201214 Nov 2012

Conference

ConferenceAustralasian Corrosion Association (ACA) Conference 2012
Abbreviated titleCP 2012
CountryAustralia
CityMelbourne
Period11/11/1214/11/12
OtherCorrosion Management for a Sustainable World: Transport, Energy, Mining, Life Extension and Modelling

Keywords

  • Aluminium
  • Electrochemical impedance spectroscopy
  • Passivity
  • Pourbaix
  • Precipitate

Cite this