The Effects of Ablative Coating Thickness at Various Laser Intensities and Multiple Laser Pulses on Thin Copper Sheet Formability in High Strain Rate Laser Shock Forming

High strain rate metal forming using laser induced shockwave pressure is used for micro‐scale deformation. Ablative coating is one of its significant process components as it generates shockwave pressure through vaporization into plasma by laser irradiation as well as impedes the shockwave propagation. The effect of ablative coating thickness on the forming behavior of thin copper foils is investigated in this paper. Various laser intensities have been used in parallel with changes in coating thickness to further study this effect. The amount of plastic deformation is analyzed with respect to coating thickness, laser intensity and the number of pulses. It is found that there is an optimum coating thickness for a given laser intensity to achieve maximum deformation depth at the center of the formed cavity. The deformation depth shows a monotonic relationship with the laser intensity. Multiple pulses improve the deformation characteristics by limiting the ablation of workpiece material.