Deep Drawing Parameters and Characteristics for the Hot Forming of AA7075

Abstract

The hot forming of 7000 series aluminum alloys, or die quenching (DQ), consists of solutionizing the blank in a furnace and subsequently stamping it in a chilled die set. Being a relatively new technology, adopting the DQ process into automotive assembly lines involved several challenges. One of these challenges is the constitutive modelling, which is being addressed in literature. Another challenge is determining the proper formability conditions for DQ to work. To this end, the work presented herein investigated different forming parameters required to successfully deep draw AA7075 discs. Two disc sizes were selected: 177.8 and 203.3 mm. Parameters that were investigated were: binder load and lubricant applied. The deep draw experiments were also modelled in the LS-Dyna finite element code, using the constitutive data and a Barlat-2000 yield surface developed in other work by the authors. The predicted deep draw curves were found to match well the experimental data. The earring profiles also matched well.