Investigation of Mg/Al alloy sacrificial anode corrosion with Scanning Electrochemical Microscopy

Authors

  • András Kiss
    Affiliation
    University of Pécs, Faculty of Science, Institute of Chemistry, Department of General and Physical Chemistry
  • Ricardo M. Souto
    Affiliation
    University of La Laguna, Department of Physical Chemistry
  • Géza Nagy
    Affiliation
    University of Pécs, Faculty of Science, Institute of Chemistry, Department of General and Physical Chemistry
https://doi.org/10.3311/PPch.2164

Abstract

Corrosion of Mg/Al alloy was investigated with the scanning electrochemical microscope (SECM) using a Mg2+ ion selective microelectrode (ISME) as measuring tip. Mg/Al alloys have practical application as sacrificial anodes to prevent the corrosion of various metals susceptible to corrosion. A typical application of such sacrificial anodes is in water boilers. A model (Mg/Al)/Fe target was fabricated using boiler sacrificial anode and high purity iron wires. Corrosion current was measured between the electrically connected galvanic pair, and Mg2+ ion flow rate was calculated with Faraday’s law of electrolysis. However, Mg2+ flow rate could not be calculated with this method while the twometals were left electrically-disconnected. For this reason, fixed height lateral scans and retreating scans were performed above the Mg2+ sample with Mg2+ ion-selective electrodes employed as SECM tips. Mg2+ flow rate was estimated using the concentration profiles obtained with SECM. Relatively high-speed scans were possible with robust, solid contact Mg2+ micropipette electrodes, owing to their low resistance compared to conventional micropipettes of the same size.

Keywords:

Scanning Electrochemical Microscope, SECM, ion-selective microelectrode, ISME, galvanic corrosion, potentiometric tip, solid contact

Citation data from Crossref and Scopus

Published Online

2013-06-26

How to Cite

Kiss, A., Souto, R. M., Nagy, G. “Investigation of Mg/Al alloy sacrificial anode corrosion with Scanning Electrochemical Microscopy”, Periodica Polytechnica Chemical Engineering, 57(1-2), pp. 11–14, 2013. https://doi.org/10.3311/PPch.2164

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Articles