Preliminary studies on electromagnetic forming of aluminum/polymer/ aluminum sandwich sheets

摘要

Since years, metal/polymer/metal sandwich sheets (MPM) are in the focus of research, not only because of their lightweight potential, but also for their arbitrary customization in aviation as well as automotive applications fields. Because of the limited forming potential of the MPM containing thin metallic skin sheets in combination with epoxy resins, improving their shaping ability is a challenge. In this paper, studies on forming of MPM sheets by electromagnetic forming (EMF), a die less, high strain rate, free-forming process were carried out. EMF bending tests at different bending radii and complex forming process (comparable to stretch forming) were attempted at different energy discharges. The results revealed that forming the MPM sheets is possible with EMF with improved results in terms of the strain values and forming depth compared to the conventional stretch forming process with fixed tools. In the EMF bending tests, several damage types could be observed due to the inappropriate selected energy level and coil/sample size ratio. These parameters have to be optimized in a follow-up study to define a proper process window.