Evaluation of corrosion resistance of AA6082-T651 aluminium alloy after laser shock peening by means of cyclic polarisation and EIS methods

Laser shock peening (LSP) without ablative coating at various power densities was applied to AA6082 aluminium alloy to investigate corrosion behaviour in a 0.6 M NaCl solution. Cyclic polarisation results showed enhanced passivity with corrosion current reduction by as much as a factor of 12, compared to the untreated specimen. Additionally, EIS after 24 h confirmed almost seven times higher polarisation resistance after LSP, compared to the untreated specimen (45 and 6.7 k Omega cm(2)). XPS analysis indicated Al2O3 enrichment, which contributed to higher corrosion resistance with reduced anodic dissolution of the LSP-treated surface due to plasma ablation and shock waves. (C) 2012 Elsevier Ltd. All rights reserved.