)>IJH=?J Corrosion is a traditional problem but still one of the most serious problems in industry. To reduce the huge economic loss caused by corrosion, tremendous eort has been made to understand, predict and prevent it. Corrosion phenomena are generally explained by the formation of corrosion cells at a metalelectrolyte interface. However, experimental verication of their nanoscale distribution has been a major challenge *

In this study, nanoscale corrosion behavior of copper fine wires in dilute NaCl solution is studied by atomic force microscopy and electron backscatter diffraction technique. The dissolution rate of the grains constituting the wires strongly depends on their crystallographic orientation. In pure water, the dissolution rate increases in the order of (111) < (001) < (110). Addition of Cl − dramatically increases the dissolution rate of the (111) surface to alter the order to (110) ≈ (001) ≈ (111) at 0.1 mM. These results show that the crystallographic orientation dependence is significantly changed by a slight increase of Cl − concentration in dilute solution.