Synergistic effects of corrosion and slow strain rate loading on the mechanical and electrochemical response of an aluminium alloy

Abstract

Tensile specimens of an aluminium alloy, AA7075, with grains aligned parallel to the tensile axis are subjected to a range of slow strain rate tensile loading in a very low pH corrosive environment. The degradation in mechanical response together with the emerging electrochemical characteristics of the material using electrochemical impedance spectroscopy (EIS) are characterized. The EIS measurements coupled with the post-mortem microscopic characterization of the specimens provide an unprecedented view of all the interfacial phenomena affecting the mechanical response of the material. A failure mechanism of the material under consideration is proposed and rationalized by a qualitative fracture mechanics analysis.