20404 Influence of short plused-laser on laser-peening in auminum alloy

We investigated the dependence of a pulse width on peening effects, such as residual stress distribution, hardness distribution, and surface roughness. Aluminum alloy (A2017-T4) was irradiated by three types of the lasers (ns, ps, and fs pulsed-lasers). As a result, the residual stress distributions in the cases of ns- and ps-laser irradiations had similar tendencies in the depth and maximum value of the compressive residual stress. On the other hand, we confirmed lower magnitude compressive residual stress by the fs-laser irradiation in comparison with the ns- and ps-laser irradiations, since the fs-laser irradiation would not cause plastic deformation required for the peening. Additionally, the ns- and ps-laser irradiations could produce higher magnitude compressive residual stress than that by shot peening.