Localized corrosion behavior of pure zinc by SECM and EBSD

Abstract

The effect of grain orientation and grain boundary angle on the microscopic corrosion behavior of pure zinc was employed by the systematic integrated SECM, EBSD and AFM analysis. With confirmed different orientation grains, we proved the zinc grain near <0001>//ND orientation shows the lowest corrosion rate compared to that near <01$\overline{1}$0>//ND and <$\overline{1}$2$\overline{1}$0>//ND orientation. Even though the grain orientation distribution is random and the grain corrosion rates of <01$\overline{1}$0>//ND and <$\overline{1}$2$\overline{1}$0>//ND orientations are similar, the <0001>//ND have the lowest reactivity. The corrosion morphology of <0001>//ND orientation grain appears hexagonal corrosion pit, and the morphology of <01$\overline{1}$0>//ND and <$\overline{1}$2$\overline{1}$0>//ND orientation grain shows striated structures. This behavior could be explained by the corrosion morphology and rate of zinc grain depending on the orientation.