Experimental Investigation of Novel Impact Hydroforming Technology on Sheet Metal Formability

Abstract

The present article aims at investigating the effect of impact hydroforming (high strain rate forming) on the formability of AA5A06. In comparison, traditional hydroforming is also conducted. The formability of AA5A06 is investigated trough hydro-bulge test at room temperature and strain rate range 4.67 × 10-3-3.18 × 103 s-1. The results show that the effective fracture equal-biaxial strain was not increased monotonically by increasing the impact velocity. There exists an optimal impact velocity, under which velocity the maximum effective fracture strain of biaxial zone increases by 62.18% compared with the quasi-static condition. It is concluded that impact hydroforming is an effective forming technology to achieve high formability and to form complex parts with low plasticity metals. In this paper the equi-biaxial strain of FLC is also theoretically calculated by Swift and M-K models. The plastic anisotropy is also taken into account during this calculation by introducing the anisotropy yield criteria, which is seldom discussed in the dynamic field. The results show that the M-K model is more suitable for calculating equi-biaxial strain of AA5A06 at high strain rate.