Stress Corrosion Cracking of Al-Zn-Mg Alloy AA-7039

Abstract Stress corrosion cracking (SCC) of aluminum alloy 7039 was investigated by following the kinetics of crack propagation as a function of environmental and metallurgical variables. The variables included: stress direction vs grain orientation, solution temperature, addition of an oxidizing inhibitor, and application of a cathodic potential. Experiments were carried out in a 3.5% NaCl solution on precracked DCB specimens. The morphology of the cracking was studied by SEM fractography. The possibility of creep being the rate controlling step in crack propagation, under the specific conditions of this study, is discussed in the light of experimental results.