On the concentration of Cl^- ions within the pitting cavities of Al-Cu alloys

Abstract

When immersed in aerated 0.1M NaCl solution for 10³ hours, Al-0.87%Cu and Al-1.30%Cu alloys give rise to pitting reactions to form cavities on the surface. It is found that the concentration of Cl^- ions within the cavities which is predicted from the drop of corrosion potential is equivalent to that in 0.1M to 0.2M deaerated AlCl₃ solution.