Evaluating the corrosion behaviour of Magnesium alloy in simulated biological fluid by using SECM to detect hydrogen evolution. (10th January 2015)

• Record Type: Journal Article
• Authors: Jamali, Sina S.; Moulton, Simon E.; Tallman, Dennis E.; Forsyth, Maria; Weber, Jan; Wallace, Gordon G.
• Is Part Of: Electrochimica acta. Volume 152(2015)
• Page Start: 294
• Page End: 301
• Publication Date: 2015-01-10
• Subjects: Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2014.11.012
• Languages: English
• ISSNs: 0013-4686

Abstract

Graphical abstract: Abstract: 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.