The anodic surface film and hydrogen evolution on Mg. (September 2015)

• Record Type: Journal Article
• Authors: Song, Guang-Ling; Unocic, Kinga A.
• Is Part Of: Corrosion science. Volume 98(2015)
• Page Start: 758
• Page End: 765
• Publication Date: 2015-09
• Subjects: A. Magnesium -- B. EIS -- B. TEM -- B. SEM -- C. Anodic dissolution -- C. Negative difference effect; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2015.05.047
• Languages: English
• ISSNs: 0010-938X

Abstract

Abstract: This study clarifies that the inner and outer layers of the anodic film consist of a nano/micro-porous MgO + Mg(OH)2 mixture. The film becomes thicker and more porous with increasing potential. It can rupture when potential is too positive in a non-corrosive Mg(OH)2 solution. Hydrogen evolution becomes more intensive as polarization potential increases, particularly when the potential at the film-covered Mg surface is close to or more positive than the hydrogen equilibrium potential, suggesting that an "anodic hydrogen evolution" (AHE) reaction occurs on the substrate Mg in film pores, and the significantly intensified AHE causes film rupture at high potential.