Modeling of Crack Chemistry in Cu‐Au Alloys

The possibility of hydrogen discharge at the crack tip during transgranular stress corrosion cracking of Cu-Au alloys in chloride solutions was examined by modeling electrochemical reactions and transport losses in cracks under steadystate conditions. To take into account the discontinous nature of the cracking, which causes periodic minima in the electrode potential at the crack tip, the minimum potential which can be reached was calculated considering the interplay of the various electrode reaction and their spreading along the crack. Kinetic parameters for the redox reactions Fe ++ |Fe +++ and Cu + |Cu ++ on gold were measured, in order to provide values for the modeling, which are unavailable in the published literature. The results show that there is no possibility of hydrogen discharge, which rules out hydrogen embrittlement as the cause of the cracking