MECHANICAL NATURE OF STRESS-CORROSION CRACKING IN Al-Zn-Mg ALLOYS - 2. ELECTROCHEMICAL-MECHANICAL MODEL.

The finding that slow crack growth during stress corrosion cracking (SCC) of 7075 aluminum comprises both an electrochemical and a mechanical component prompted a review of several possible mechanical models and seven possible controlling thermally activated processes. Since no existing interpretation could satisfy all of the observations, an empirical model was developed. The conclusion is that slight modification of many existing proposed mechanisms could explain the general features of SCC but that any theoretical model must contain some aspect of the mechanical rupture process.