Localized currents and pH distribution studied during corrosion of MA8 Mg alloy in the cell culture medium. (1st July 2020)

• Record Type: Journal Article
• Authors: Gnedenkov, A.S.; Mei, D.; Lamaka, S.V.; Sinebryukhov, S.L.; Mashtalyar, D.V.; Vyaliy, I.E.; Zheludkevich, M.L.; Gnedenkov, S.V.
• Is Part Of: Corrosion science. Volume 170(2020)
• Publication Date: 2020-07-01
• Subjects: A. Magnesium -- A. Alloy -- B. SEM -- B. XRD -- C. Passive films; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2020.108689
• Languages: English
• ISSNs: 0010-938X

Abstract

Graphical abstract: Highlights: Electrochemical behaviour of MA8 Mg alloy in MEM and 0.83 wt. % NaCl is analyzed. SVET and SIET studies can be performed in rather complex biological medium MEM. Hydrogen evolution rate is higher for the samples in 0.83 wt. % NaCl than in MEM. Formation of the specific film on alloy stabilizes the local pH of MEM below 9.0. Probable formation of organic acids in MEM increase the activity of Mg alloy. Abstract: Electrochemical behaviour of MA8 magnesium alloy in minimum essential medium (MEM) and 0.83 wt. % NaCl solution is compared using SVET, local pH measurements and hydrogen evolution tests. Corrosion products formed on the alloy surfaces are characterized using XRD and SEM-EDX analysis. Potential by-products of cells and bacteria activities increase the sample activity in MEM at the initial stage of material immersion. Hydrogen evolution rate is higher for samples in NaCl solution in comparison with MEM. Formation of partially protective magnesium-substituted hydroxyapatite stabilizes the local pH of MEM below 9.0 and does not allow to increase the pH during corrosion.