X-ray photoemission investigation of the corrosion film formed on a polished Cu-13Sn alloy in aerated NaCl solution

When a polished Cu-13Sn alloy is soaked in a stagnant aerated 0.5 M NaCl so lution. a corrosion process occurs. X-ray photoelectron spectroscopy (XPS) shows that the initial surface is covered with a thin SnO2 layer and that a fter immersion Cu2O and SnO2 are the main components of the corrosion layer . The ratio between these two oxides varies with the immersion rime. At the beginning of the immersion, the thickness of the initial SnO2 layer increa ses due to selective copper dissolution. Then the tin oxide film gets progr essively buried beneath a Cu2O him. This study allows us to conclude that a s for pure copper. the corrosion process of a polished Cu-13Sn alloy in NaC l solution occurs by diffusion of Cu(I) species through the oxide layer. (C ) 2001 Elsevier Science B.V. All rights reserved.