Effect of Crystallographic Texture on the Formation of Residual Stresses in Aluminum Alloys during Laser Shock Peening without Coating

We examine the effect of laser shock peening (LSP) without coating by low-energy (0.3 J) pulses on the structure and residual stresses in a deformed AMg6 aluminum alloy with different crystallographic textures prior to and after recrystallization annealing. It is shown that the initial texture of the alloy dramatically affects the profile and depth of residual stresses after LSP. It is found that the depth and profile of compressive residual stress (CRS) in the aluminum alloy depend on the orientation of the crystallographic planes relative to the applied force. The smallest depth and magnitude of CRS are obtained when the slip plane is located perpendicular to the applied force. With a favorable crystallographic texture, the CRS depth increases by 1.5 to 3 times, depending on the laser power density and spot diameter. It can be argued that the crystallographic texture of the LSP-processed (LSPed) alloy is one of the main factors influencing the results of laser shock peening.