Simulation and Experiments for Hot Forming of Rectangular Pans in Fine-Grained Aluminum Alloy AA5083

Accurate numerical simulation capability is critical to the development and implementation of hot forming technologies. Numerical simulations were developed for gas-pressure forming of commercial, fine-grained aluminum-magnesium (AA5083) material into deep pan shapes at 450 degrees C. These simulations utilize a material constitutive model recently developed for fine-grained AA5083 materials as a user-defined routine in commercial Finite Element Method (FEM) software. Results from simulations are compared against data from gas-pressure forming experiments, which used the same forming conditions and die geometries. Specifically, local sheet thinning and radius of curvature in edges and corners are compared between simulation and experiment. Numerical simulations are in good agreement with experiments for local sheet thinning of up to 50%. For locations where sheet thinning exceeds 50%, simulations predict less thinning and larger formed radii than observed in experiments. It is likely that cavitation, which is not accounted for in simulations, plays a significant role in causing a decrease in simulation prediction accuracy for thinning values greater than 50%. This study demonstrates a simulation capability that is potentially of significant practical use for predicting the hot gas-pressure forming of fine-grained AA5083 material.