Influencing laser shock peening treatment of the mechanical,tribological,corrosion,and microstructural characteristics on AA5052 alloy

Abstract

This study examines the effects of laser shock peening parameters on the structural, mechanical, tribological, and corrosion properties of AA5052 aluminum alloy. The LSP process uses specific parameters, detailed in Table 2, to induce ultra-high plastic strains and strain rates in the material. The research demonstrates significant improvements in both surface hardness (48.29% increase) and tensile strength (24.63% increase) for the optimized LSP conditions. The treatment results in a maximum compressive residual stress of 231.02 MPa near the surface, concentrated within a depth of 100 μm. X-ray diffraction analysis reveals the formation of Mg₂Al₃ (β) precipitates on the LSP surface, along with peak broadening and shifting indicative of residual stress. These precipitates, along with the high dislocation density caused by severe plastic deformation during LSP, are contributed to the enhanced mechanical properties. Electron backscatter diffraction and transmission electron microscopy observations on the LSP-treated AA5052 confirm the introduction of dislocation shifts, deformation twins, and refinement of grain structure. Additionally, the LSP treatment (1.046 × 10⁻³ mm/N-m³) significantly improves wear resistance compared to unpeened alloy (4.482 × 10⁻³ mm/N-m³), with a wear rate reduction of over 76.6% during the linear reciprocating tribometer. Finally, electrochemical corrosion tests demonstrate superior corrosion resistance in LSP-treated AA5052 (corrosion rate of 0.0116 mm/yr) compared to the unpeened alloy (0.0551 mm/yr). This study demonstrates that LSP significantly enhances the mechanical performance and corrosion resistance of AA5052 alloy, establishing it as a valuable candidate for shipbuilding applications that require superior durability.