Research Information System
Corrosion Science, vol.52, no.9, pp.3109-3117, 2010 (SCI-Expanded)
DC polarization and electrochemical impedance spectroscopy techniques were used to investigate the pH dependent anodic behaviour of tungsten in basic solutions. Anodic currents of W were pH independent between pH 8 and 11. Above pH 12 as pH increased the anodic currents of W also increased. The diffusion control in pH independent regime was observed to arise from slow diffusion of the solubilized species. At higher pH levels, however, OH- ion diffusion from bulk of solution was observed to control the anodic process. Hydrate layer formation, which was observed with low frequency capacitive loop formation, accelerated with increase in pH. © 2010 Elsevier Ltd. All rights reserved.