Warm Deep Drawing of Aluminium Sheet

Aluminium sheet drawing processes can be improved by manipulating local flow behaviour by means of elevated temperatures and temperature gradients in the tooling. Forming tests showed that a substantial improvement is possible not only for 5xxx but also for 6xxx series alloys. Finite element method simulations can be a powerful tool for the design of warm forming processes and tooling. Their accuracy will depend on the availability of materials models that are capable of describing the influence of temperature and strain rate on the flow stresses. Two models, an adapted Nadai power law and a dislocation based Bergström type model, are compared by means of simulations of a cup drawing process. Experimental drawing test data are used to validate the modelling approaches, whereas the model parameters follow from tensile tests.