Numerical Prediction of Failure Mechanism of AA7075 at the Elevated Temperatures

Aluminum alloys have primary potential for lightweight structural application in automotive and aerospace industries. Among these, the 7000 aluminum series are very attractive materials in the automobile and aerospace industries. Despite of the obvious advantages of the lightweight alloys, their notable drawback is their formability which is significantly lower than traditional steel alloys at room temperature conditions. Nevertheless, the formability of the aluminum alloys increases with an increasing forming temperature up to the recrystallization temperature. The present study illustrates the formability of AA7075 under various strain rates at elevated temperature. In this experiment, formability of circular plates is investigated, considering the maximum possible stretched heights. The experiments were done in temperatures 400, 450 and 500 and the punch velocity varied from 5 to 200 mm/min. The results show that the maximum dome height is possible in temperatures around 400 c, for this material at lower strain rates. Also results show as the strain rate increases, the height decreases.

Keywords:

Hot sheet metal forming , Finite elements , Strain rate , AA7075 , Ductile failure