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Evaluating the corrosion behaviour of magnesium alloy in simulated biological fluid by using SECM to detect hydrogen evolution

journal contribution
posted on 10.01.2015, 00:00 authored by S S Jamali, S E Moulton, D E Tallman, Maria ForsythMaria Forsyth, J Weber, G G Wallace
Scanning electrochemical microscopy (SECM) in surface generation/tip collection mode is investigated as an assessment tool for studying the corrosion behaviour of magnesium in simulated biological fluid. The technique provides a local map of hydrogen (H2) evolution which alone can be used as a direct measure of corrosion. The H2 generated during corrosion of magnesium is oxidized at the probe(i.e. a Pt ultra micro-electrode);with the magnitude of the current generated due to oxidation being indicative of the intensity of H2 evolution at a local scale on the magnesium surface. This method was calibrated using a cathodically polarized Pt disk to simulate H2 evolution in a controlled condition on a homogeneous surface. Potential interference from dissolving Mg or high local pH was also investigated. The technique was implemented for studying H2 evolution at the surface of AZ31 as a model Mg alloy.SECM results combined with SEM-EDX and profilometry data revealed that local domains of higher H2 evolution on the surface of AZ31 are in close proximityof the observed pitting sites.

History

Journal

Electrochimica acta

Volume

152

Pagination

294 - 301

Publisher

Elsevier

Location

Amsterdam, Netherlands

ISSN

0013-4686

Language

eng

Publication classification

C Journal article; C1 Refereed article in a scholarly journal

Copyright notice

2015, Elsevier