Experimental and numerical study on the influence of process parameters in electromagnetic compression of AA6061 tube

ABSTRACT

High velocity forming (HVF) technique is a forming process that deforms tubes and sheets with added advantages like less springback, wrinkling, improved strain distribution, better surface finish, and improved product quality. Electromagnetic forming is one of the HVF processes that work on the principle of electromagnetic induction and Lorentz force. In the present study, electromagnetic compression of AA6061 tube has been studied experimentally and analytically using finite element method simulation. Aluminum alloy AA6061 tubes of 56 mm outer diameter (OD) and 1 mm thickness were compressed using a four-turn bitter coil with the help of 40 kJ capacitor bank. A range of energy generated from a single and/or double capacitor banks was applied and gap between coil inner diameter and tube OD was varied to study their effect on deformation. Resultant velocity, magnetic field, effective plastic strain, displacement, and current density were calculated numerically and their effect on compression is compared. A regression equation has been developed using a factorial design of experiment method to calculate the rib depth at various energy and gap. A correlation was established between discharge energy and gap with deformation of tube, and variation of various numerically calculated parameters was analyzed.

KEYWORDS:

• Magnetic force
• capacitor bank
• electromagnetic compression
• high strain rate
• factorial design

Acknowledgments

The authors gratefully thank Director CSIR AMPRI, Bhopal and Director RRCAT Indore for providing all necessary facilities for this research work.