Efficiency improvement of thin-sheet-metal bending by femtosecond laser peen forming

摘要

Femtosecond laser peen forming is die-less incremental sheet forming using laser induced shock waves. It was applied to bending of thin sheet micro parts. When severe curvatures are requested, the process needs dense laser pulse irradiation, which reduces sheet thickness remarkably owing to excessive laser ablation. High bending efficiency per pulse is necessary to realize a small radius of curvature without sheet thickness reduction. The authors attempted to improve the bending efficiency by changing scanning velocity and scanning pitch. Optimized scanning achieved 40% smaller radius of curvature than conventional one, in spite of same irradiated pulse density. Obtained knowledge is effective in miniaturization and productivity increase.