Analysis of Semi-Hot Forming Behaviour of AA7075 Sheet Metal

7xxx series aluminium alloys have a high potential for lightweight constructions in automotive applications due to lower weight, similar strength and higher recyclability compared to steel. However, formability of such alloys at room temperature is relatively low. Elevated temperatures are one way of improving formability, e.g. by semi-hot forming. This work is therefore concerned with the analysis of strain rate and temperature dependent behaviour of AA7075 in T6 state. For this, experimental characterisation has been performed using uniaxial and shear tension, layer compression, plane strain compression and Nakajima tests over temperatures of 20 to 275 ℃ and strain rates of 0.01 to 1 s−1. The experimental results are used to calibrate and build a temperature and strain rate dependent plasticity model using Hockett-Sherby hardening law. For failure modelling, a temperature dependent forming limit curve was calculated. Additionally, various yield criteria were applied to predict a temperature dependent yield locus for a constant strain rate.