Efficacy of Laser Shock Peening Post-milling: A Semi-numerical Study

The role of the initial residual stresses (IRS) induced by the milling on the efficacy of laser shock peening (LSP) was investigated numerically on IN718 specimens. Three milling conditions exhibiting high (3.5 μm), medium (1.1 μm), and low (0.6 μm) surface roughness were considered for LSP. Experimentally measured (from XRD) milling-induced sub-surface (up to 60 μm depth) residual stresses were introduced into the simulations of LSP as predefined fields. The role of spot diameter with the IRS on the LSP-induced residual stress was studied systematically. For most cases, the tensile IRS from milling caused a significant decrease in the magnitude of maximum compressive residual stresses induced by LSP.