Integrated AFM and SECM for in situ studies of localized corrosion of Al alloys
2007 (English)In: Electrochimica Acta, ISSN 0013-4686, E-ISSN 0019-4686, Vol. 52, no 27, 7697-7705 p.Article in journal (Refereed) Published
Rolled 3xxx series Al alloys, e.g., EN AW-3003, are generally used as fin or tube material in heat exchangers for automobiles. With reducing fin thickness, maintaining fin material integrity is of increasing importance. This study aimed at exploring the differences in intrinsic corrosion properties between EN AW-3003 and a newly developed Al–Mn–Si–Zr fin alloy using state-of-the-art local probing techniques. Volta potential mapping of both alloys by scanning Kelvin probe force microscopy (SKPFM) indicates a cathodic behaviour of constituent intermetallic particles (>0.5 μm) relative to the alloy matrix. Compared to EN AW-3003, the Al–Mn–Si–Zr alloy has a smaller number of particles with large Volta potential difference relative to the matrix. In situ atomic force microscopy (AFM) measurements in slightly corrosive solutions showed extensive localized dissolution and deposition of corrosion products on EN AW-3003, and only a small number of corroding sites and “tunnel-like” pits on Al–Mn–Si–Zr. Probing the ongoing localized corrosion process by integrated AFM and scanning electrochemical microscopy (SECM) revealed more extensive local electrochemical activity on EN AW-3003 than on Al–Mn–Si–Zr. In all, the lower corrosion activity and smaller tunnel-like pits resulted in lower material loss of the Al–Mn–Si–Zr alloy, a beneficial property when striving towards thinner fin material.
Place, publisher, year, edition, pages
2007. Vol. 52, no 27, 7697-7705 p.
Al alloy; Localized corrosion; SKPFM; In situ AFM; Integrated in situ AFM/SECM
IdentifiersURN: urn:nbn:se:kth:diva-7854DOI: 10.1016/j.electacta.2006.12.073ISI: 000249857800026ScopusID: 2-s2.0-34547862411OAI: oai:DiVA.org:kth-7854DiVA: diva2:12999
QC 20100705. ELECTROCHEMICAL METHODS IN CORROSION RESEARCH Selection of papers from the 9th International Symposium (EMCR 2006) 18-23 June 2006, Dourdan, France 2007-12-182007-12-182012-03-19Bibliographically approved