Effect of coil design parameters on performance of electromagnetic forming process

ABSTRACT

Coil is an important part of an electromagnetic forming system. Its design depends on the shape of the workpiece and its application. In the present work, effect of various parameters of coil design like inner diameter (ID), outer diameter (OD), effective number of turns (η), and cable connection on performance of coil have been established. Its performance have been quantified in terms of change in inductance, resistance, and subsequently on the current pulse and deformation of tube. The variation of inductance and resistance of the coil with respect to change in ID, OD, η, and cable connection have been determined experimentally and analyzed. The performance of the coil is also correlated in terms of theoretically and experimentally determined current pulse and its effect on overall inductance of the system. Further, Q-factor of the coil have been determined and analyzed to establish the loss in the coil. Small change in diameter and effective number of turns can change the amplitude of current pulse by 30 kA approximately. Additional parallel discharge cable can improve current and frequency by approximately 26% and 23%, respectively. The established performance of the coils have been experimentally and numerically validated by deforming an aluminum AA 6061 tube.

KEYWORDS:

• Electromagnetic forming
• bitter coil
• inductance (L)
• resistance (R)
• frequency
• Q-factor
• tube deformation

Acknowledgments

The authors would like to thank Director, CSIR-AMPRI Bhopal for providing the facilities and CSIR New Delhi for support to perform this work.