Research on the electromagnetic blanking based on force-free region deformation: simulation and experiments

Abstract

Electromagnetic blanking (EMB) based on force-free region deformation is proposed to meet the no burr forming requirement of diaphragm parts for carrier rockets in the aerospace field. Deformation behaviors of the part were revealed along with the effects of key process parameters on the forming quality investigated. During the EMB process, the electromagnetic force, effective stress, and plastic strain were distributed in a rather uniform annular region and peaked near the edge of the die. High-speed deformation coupled tension and bending were evidenced. With the increase in discharge voltage, the diameter of the part reduced slightly, and the filling degree of the trimmed edge section reduced remarkably, while the thickness uniformity was improved. It was found that the filling degree was dependent on the deformation degree and the interaction between two different regions. Similar effects of initial blank diameter and discharge voltage were observed. The interaction was notable at a larger initial blank diameter, causing the sharper drop in the filling degree. The forming quality could be improved by using a blank holder, but an undesirable extra deformation zone would appear. In a word, the proposed EMB process is capable of forming no burr diaphragm part with high quality.