Numerical and experimental investigations of laser shock hydraulic microforming for thin-walled foils

摘要

This paper proposes a novel laser shock hydraulic microforming technology which employs laser-induced shock wave pressure to deform thin-walled metal foils into the large-area three-dimensional micro arrays with the liquid as the pressure transmission medium. Both numerical simulation and experimental methods were used to investigate the laser shock hydraulic microforming of pure copper foils. A finite element model was built and a method of discrete spatiotemporal Gaussian distribution laser shock wave pressure was applied in the simulation, and the experimental measurements were well consistent with the simulation results, which verifies the accuracy of the model. The dynamic forming process, as well as the deformation behaviors, including the velocity variation and strain distribution, were studied through the model. The pressure distribution equalization and the spring back during the forming process were found and discussed. In addition, the influence of the laser energy and foil thickness on the formability of thin-walled copper foils were studied. The numerical and experimental investigations have shown that this technology has a good pressure equalizing effect and can suppress or even prevent the springback of copper foils, which is suitable for the forming of large-area array micro features.