Effect of Impact Hydroforming Loads on the Formability of AA5A06 Sheet Metal

Recently, aluminium (Al) alloys are increasingly used in the automobile and aerospace industries because of their light weight and corrosion resistance properties. However, the applications of these materials are limited due to their poor formability especially at room temperature. Although hydroforming technology is one of the approaches used to improve the formability of Al alloys, it still cannot fulfil the requirements of designers and manufacturers to form high-quality complex shaped components. It has been found that high-speed forming is able to improve the formability of low plasticity metals at room temperature. Thus, impact hydroforming (IHF) technology is proposed by combining the advantages of high-speed forming and hydroforming, and it was used to address the issues of quasi-static hydroforming. Accordingly, the aim of this study is to investigate the effect of IHF on the formability of AA5A06 sheet metal. An IHF bulge experiment setup was developed by making use of a light gas gun which can accelerate the projectile up to 300m/s. The results show that the formability of the AA5A06 increased under most of the impact velocities, and the equi-biaxial strain before failure of the IHF is 50% higher than that of quasi-static hydroforming at strain rate of 2 × 10³ s⁻¹. It is concluded that the IHF technology is an appropriate method to improve the formability of Al alloys and form complex shape components. (paper)