Numerical and Experimental Investigation of Effective Parameters on Formability of Al-St Two Layer Sheet Metals

Recently, the use of laminated sheet metals has been spread in various industries, such as aerospace and automotive industries due to the improvement of formability of low-formable lightweight sheets and making compound properties such as corrosion resistance. Forming these sheets is faced with some limitations, such as wrinkling and separation of the layers. To overcome these limitations, hydroforming process has been introduced. In this paper, hydrodynamic deep drawing assisted by radial pressure and also hydromechanical deep drawing processes of Al-St two-layer sheet metals have been investigated experimentally. In order to perform a detailed investigation, finite element simulation was also carried out by ABAQUS software. It was shown that formability of the aluminum sheet can be improved by laminating with the steel sheet. Moreover, the results illustrated that in hydrodynamic deep drawing assisted by radial pressure, wrinkling is decreased and thinning is increased by reducing the gap between blank holder and die. When the gap becomes zero (hydro-mechanical deep drawing without radial pressure), wrinkling is reduced considerably and also drawing ratio is decreased. Additionally, it was identified that the arrangement of the layers with respect to the punch has a great effect on formability of the two-layer sheet