Effects of ablative and non-ablative laser shock peening on AA7075-T651 corrosion and fatigue performance

The fatigue performance from pre-corroded pits was studied in laser-shock-peened AA7075-T651 with and without a protective ablation-layer. Surface microstructural characterisation showed laser-shock-peening generated residual stresses up to −400MPa, limited hardness moderate surface roughness increase. specimens were exposed 3.5 wt-% sodium chloride solution for different levels of galvanostatic control. compressive did not significantly affect corrosion behaviour, or pit morphology. Laser-shock-peening-induced had the most detrimental impact on performance. Fatigue testing act as stress concentrations. Cracks initiated shortly after dynamic loading, reducing life by 50%. Laser-shock-peening increased 400% compared corroded-untreated AA7075-T651, due effectively counteracting concentrations produced pits.Highlights Pre-corroded laser-peened (LSP LSPwC) is investigated.XRD incremental hole drilling show deeper LSPwC LSP.Electrochemical tests no significant changes behaviour laser peening.Fatigue fractography counteract at pits.