Investigation on residual stress distribution in thin plate subjected to two sided laser shock processing

Two sided laser shock processing (TSLSP) has been an innovative process to impart the favorable compressive residual stresses into thin components without producing excessively detrimental deformation. In this paper, the investigations focus on the residual stresses distribution in the 7075-T7351 alloy plate with thickness of 2 mm, whose both side surfaces are subjected to shock waves with peak pressure 2 GPa induced by laser with duration 24 ns. The dynamic propagation and attenuation process of stress waves in thickness direction of the plate is also investigated, and the critical factors on residual stresses field are further discussed. The results reveal that the whole thickness section between the irradiated areas is distributed with the compressive residual stresses, while the surrounding of the region distributed with compressive residual stresses is accompanied by the tensile residual stresses. The distribution characteristic of residual stresses in the processed plate is closely related to the exact values of the applied parameters in TSLSP treatment.