Investigation on deformation control of sheet metal in radial Lorentz force augmented deep drawing

A process variant of electromagnetic sheet forming, known as radial Lorentz force augmented deep drawing, has been recently developed to promote the material flow control in high-velocity forming process. Unlike conventional electromagnetic sheet forming, this new process introduces an additional radial inward Lorentz force at the flange region to enhance the draw-in material flow. Previous works have illustrated the feasibility of the process for altering the dynamic deformation behavior and, therefore, the final deformation morphology. This paper further explores the versatility of this process on deformation control by scheduling a wider range of the discharge voltage combinations. While previous works reported two potential types of the final deformation profiles, i.e., convex and flat shapes, this paper further suggests a concave shape and shows adjustment of the deformation profile in a flexible manner by altering the process parameters. To reveal the control rule for forming shape, we established two process windows in terms of two discharge voltages or in terms of draw-in and forming height, based on experimental and numerical results. In addition, new insights into the mechanisms behind different deformation modes have been gained from the analysis of the dynamic deformation process. This work demonstrates the versatility of the process, which offers an improved ability for deformation control in the context of electromagnetic sheet forming.