A novel hybrid hot forming process concept for high strength aluminum alloys

Abstract. The present study focuses on the numerical and experimental feasibility of a novel hybrid hot forming process involving solution heat treatment and a combined deep drawing and gas-based forming for high strength aluminum alloys. For this, FE simulations are first carried out by establishing a numerical model of the hybrid forming process in order to identify the process parameters to ensure macroscopic failure-free forming of a complex-shaped cross-die and counteract on localized thinning. In addition, an integrated hybrid forming test setup is realized to form the cross-die specimen for validating the numerical predictions. The numerical parameter studies suggest a suitable initial blank size for forming the cross-die, and the influence of the blank holder force and the friction coefficient on the maximum thinning at the cross-die radii. The following forming experiments show a high dimensional accuracy after deep drawing and gas-based forming steps. Comparing the individual forming steps moreover reveals that a higher local thinning is introduced during the gas-based forming. Finally, the comparison between the simulation and the experimental results demonstrates a good agreement for local thinning.