Formability evaluation for low conductive sheet metal by novel specimen design in electromagnetic forming

Abstract

In this article, we report a new method to test the formability of low conductive metal sheet under electromagnetic forming using a single planar spiral coil. Proposed novel design of test articles can produce the biaxial tensile strain state, uniaxial tensile strain state, and plane strain state, respectively. The three strain states created by the novel specimen designs were then verified by simulations. Finally, the forming limits of Ti-6Al-4V sheet metal in three different stain states during electromagnetic forming were determined by corresponding experiments using the novel specimen designs. The results indicate that the new method is reasonable and reliable. Formability of Ti-6Al-4V titanium alloy experienced significant improvement when compared with that in quasi-static condition. The extent of improvement was greatest in the plane strain state, reaching 73.65 %. The proposed specimen designs can also be used to test the formability of sheet metal under quasi-static conditionse.