EXPERIMENTAL RESEARCH ON LASER SHOCK WAVE LOADING MECHANISM OF 2024 ALUMINUM ALLOY SHEET

2024 aluminum alloy sheets with three different thicknesses were shocked by means of a single laser shock processing. Static and dynamic strain signals from the strain gauges on the back of the target were measured by STSS-1 stress test module. Residual stresses of target surfaces were measured by XRD. The loading model by the laser shock waves in 2024 aluminium alloy sheets was established, the stress wave propagations and stress wave structures inside the targets were described, and the reasons of generating residual tensile stress in the impact areas were explained. The results indicate that laser shock waves reflected and transmitted have different properties and intensities at the different places of target surfaces. When the laser power density is far beyond the best power density range of 2024 aluminum alloy and the target material is thin enough, the tensile residual stresses are generated.