Effect of pre-corrosion on damage evolution and crack propagation in aluminum alloy 7050-T7651

This paper investigates the effects of pre-corrosion on the tensile behavior of aluminum alloy 7050-T7651. A combined experimental approach involving digital image correlation, scanning electron microscopy, and tensile testing is presented for quantitative and qualitative analysis. A tensile damage model is presented for plasticity-induced, post-corrosion mechanical damage for interpretation and identification of damage and cracking thresholds. Although multiple corrosion-induced cracks evolve simultaneously in diffuse regions, propagation and coalescence of the main cracks, originating from key damage regions, dominate the failure process. A combined corrosion and mechanical damage model was used to successfully predict the effects of pre-corrosion on the tensile stress-strain response.