Analysis of laser shock waves and resulting surface deformations in an Al-Cu-Li aluminium alloy

Abstract

Laser shock processing (LSP) is now a recognized surface treatment for improving fatigue or corrosion behaviour of metallic materials through the generation of a compressive stress field. In turn, the analysis of shock wave propagation is of primary importance to predict numerically morphological and mechanical surface modifications. Considering experimental and numerical analysis of shock wave propagation, and surface deformations induced by single impacts, a 2050 aluminium alloy having different microstructural was investigated under laser-shock loading. In a first step, the evolution of shock wave attenuation and elastic precursor amplitude was correctly reproduced by finite element simulations, and in a second step, surface deformations induced by 1 to 6 local impacts were also compared satisfactorily with experiments. This allowed us to validate mechanical loading and materials’ constitutive law, but did not allow determining accurately residual stress fields on a single impact.