Electromagnetic forming and perforation of Al tubes

Abstract

Electromagnetic forming (EMF) is a high energy rate forming process which utilizes electromagnetic force to deform metal workpiece. In this research work, experiments have been conducted to establish the feasibility of electromagnetic forming and perforation (EMFP) of Al tubes. EMFP combines electromagnetic forming with electromagnetic perforation. For the feasibility study split die, pointed and concave punches were designed. The detailed study of the effect of process parameters on EMFP of Al tubes has been carried out. The optimum discharge energy was determined with experimental trials which lead to successful forming and perforation of the tube. In the case of 12-hole perforation with 5 mm stand-off distance, optimum discharge energy observed for pointed punch was 6.2 kJ whereas for the concave punch it reduced to 5.7 kJ. In the case of 36-hole perforation by a concave punch with 10 mm stand-off distance, optimum discharge energy observed was 6.2 kJ. Experimental results show that the concave punches were more suitable for perforation operation as complete removal of blank took place. EMFP overcomes the disadvantages of the formation of burrs and slivers in conventional shearing and perforation.