Energy-Level Effects on the Deformation Mechanism in Microscale Laser Peen Forming

Laser microscale peen forming has recently received more and more attention as a viable laser processing technology as it not only imparts desirable residual stress for improvement of fatigue life of the material, but can also precisely control part deformation. In the present study, the effect of energy level on the deformation mechanism in laser microscale peen forming was investigated by both numerical and experimental methods. Deformation curvatures and residual stress distributions of both sides of the specimen, characterized by X-ray microdiffraction, were compared with the results obtained from FEM simulation. The forming mechanism for convex and concave bending was explained in terms of the resulting pressure, compressive stress distribution, and plastic strain. Differences in residual stress distribution patterns were also investigated as a function of the forming mechanism.