Effect of Coil Design on Tube Deformation in Electromagnetic Forming

Electromagnetic compression is a high energy rate forming process; in which workpiece in the form of tubes are deform using energy from capacitor bank. This process is a contact free process. It is a solid state forming process. At quasi state condition, less formability of material is found and it create drawback in the form of springback, wrinkling and nonuniform thickness. But at high strain rate materials like 5xxx, 6xxx and 7xxx shows an excellent formability and reduced the springback, wrinkling and enhanced the surface quality. In the present work, electromagnetic compression of Al6061 tube has been carried out experimentally as well as analytically using finite element method simulation. The objective of the deformation is to study the effect of number of turns and axial length of coil on deformation. Al6061 tubes of 56 mm outer diameter (OD) and 0.85 mm thickness were compressed using a four-turn, five-turn and six-turn compression coil using 40 kJ capacitor bank. Compression of the tube is done with the help of capacitor bank charged to 2.3 kJ at 9 kV