Abstract
A polarization measurements of 99.999% purity aluminum specimens in acid, neutral and alkaline solutions in which they are chemically and electrochemically pretreated, have been made to clarify the difference of electrochemical behavior between in general dissolution range and in pitting attack occurrence range. It is discussed that the reaction of general dissolution corresponds to that of metallic aluminum to aluminum hydroxide and the reaction of pitting attack corresponds to that the metallic aluminum combines with chloride ions to form aluminum chloride compounds such as AlCl2+ and AlCl2+.
