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.Highlightscenter dot Full-field macro-microscale characterization of tensile damage and cracking for aluminum alloy using digital image correlation, scanning electron microscopy, and tensile testing.center dot Corrosion-plasticity damage mechanics model for effects of pre-corrosion.center dot Identification of post-corrosion evolution of damage, strain, micro-cracking initiation, and coalescence, as well as crack orientation and propagation.center dot Multiple diffuse cracks evolve simultaneously, but propagation-coalescence of main cracks in key damage regions dominates failure process.This research was supported by the National Natural Science Foundation of China (NSFC, Grant Nos. 11502285 and 11472298), the Science Foundation Ireland (SFI, Grant No. 14/IA/2604), and the Fundamental Research Funds for the Central Universities (FRFCU, Grant No. 3122014H006).peer-reviewe