Laser shock peening (LSP): Electrochemical and hydrodynamic investigation of corrosion protection pre-treatment for a copper surface in 3.5 % NaCl medium

Non-destructive laser pre-treatment was successfully imparted on the copper surface through the laser pulse peening process after covering with polyvinyl chloride (PVC) tape. In this manner, the surface was mildly stretched and residual stress was induced on the metal via compression that followed at the removal of the laser light. The surface peening process in this research is cost-effective and displayed a tremendous improvement in the corrosion resistance of Cu in aggressive chloride medium, with a promising advantage of prolong protection under flow condition. [Display omitted] •Polyvinyl chloride (PVC) prevents surface meltinting and provides a mild residual stress.•Compressed compact surface leads to low wettability and improves metal hardness.•Increase in grain refinement was only on the top surface, approximately 1733 μm.•Laser peening process improved copper corrosion resistance in 3.5 % NaCl solution.•Extended immersion and flow test validate the efficiency of the surface modification. Besides electrochemical corrosion protection, laser shock peening provides extended fatigue life and mechanical properties for metals, as reported in the literature. However, most of the studies were performed under static conditions. The effectiveness of this method under flow conditions and prolonged immersion duration is addressed in this study. Copper discs were peened with Nd: YAG laser in the presence of ∼2 mm thickness of water and polyvinyl chloride to absorb the intensity and provide residual stress without surface damage. Electrochemical and hydrodynamic analyses indicate that the peened surface showed higher corrosion resistance in 3.5 % NaCl compared to the unpeened.