Electromagnetic Forming and Joining for Automotive Applications

Abstract

In this paper some options of how electromagnetic forming (EMF) can assist to expand the capabilities of conventional forming and joining technologies are discussed. Three different areas where EMF has the potential for a significant expansion of capabilities of traditional technologies are reviewed: 1) restrike operation to fill sharp corners of automotive panels; 2) low energy method of springback calibration; 3) joining of closed frames with an openable coil. Each of these applications was demonstrated in laboratory conditions and the description of the tooling is provided in the paper. Suggested design of a flat concentrator collecting induced electric currents from a flat coil was demonstrated for a corner filling operation and a springback calibration. An efficient technique of fabricating the flat coil from a flat plate by using water jetting technology enables a cost effective coil design, which can be reinforced by a system of non-conductive bars. The insulation of the coil is produced from the flat sheet of insulation material. Suggested design allows the coil to be repaired if a shortcut or fracture of insulation strips happens. A technology of low-energy calibration of stamped parts provides an option of working with a wider variety of materials including aluminum alloys, mild steels, and advanced high-strength steels. This technology is demonstrated for calibration of U-channels.