Mechanism of Pit Initiation on Aluminum Alloy Type 7075.

摘要

The influence of anions on the initiation of pitting and the kinetics of pit growth on aluminum alloy Type 7075 has been investigated. The order of reaction (i.e., the number of anions per Al surface reaction site) and the energy of activation for pitting initiation have been measured in F(-), Cl(-), Br(-), and I(-) solutions. The technique involved potentiostating the alloy in the range of anodic passivity, injecting a solution of halide ion, and recording the time at which an exponential increase in corrosion current occurs.