Laser shock processing of 2024-T62 aluminum alloy

Laser shock processing (LSP) is a relatively new technique for strengthenin g 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 202 4-T62 aluminum alloy were investigated. The fatigue life of the laser-shock ed specimens was two times greater than that of the unshocked specimens. Th e fatigue crack growth rates (FCGRs) at a given stress intensity were reduc ed by over one order of magnitude. The fatigue behavior improvements were a ttributed to a combination of increased dislocation density, decreased surf ace roughness and compressive residual stress induced by the laser shock wa ves. (C) 1998 Elsevier Science S.A. All rights reserved.