Abstract:

LY2 aluminum alloy samples were processed by pulse laser shock to fabricate a film of 1.7 mm depth on the sample surface. The residual stresses in the directions parallel and perpendicular to the sample surface were measured using Xray stress tester, and the microtopography of the crosssection of the film was studied. Results show that the spot overlapping rate plays an important role in the distribution of surface residual stress. The maximum compressive residual stress is located in the surface or the nearsurface, and compressive residual stress in the depth direction and its change rate are inversely proportional to the depth to the surface. The residual stress increases with the number of laser shocks, but the depth of the surface film changes a little with the number of laser shocks.

Key words: optoelectronics and laser, laser shock processing, residual stress, microtopography, LY2 alloy, film