Laser shock processing of 2024-T62 aluminum alloy

Laser shock processing (LSP) is a relatively new technique for strengthening metals. A method developed for optimizing the LSP parameters is reported in this paper. The effects of LSP on the microstructure, hardness, surface roughness, residual stress, fatigue life, fatigue crack growth (FCG) of 2024-T62 aluminum alloy were investigated. The fatigue life of the laser-shocked specimens was two times greater than that of the unshocked specimens. The fatigue crack growth rates (FCGRs) at a given stress intensity were reduced by over one order of magnitude. The fatigue behavior improvements were attributed to a combination of increased dislocation density, decreased surface roughness and compressive residual stress induced by the laser shock waves.