An experimental study of hydroforming deep drawing

Hydroforming deep drawing is one of the special deep drawing processes which has been introduced in order to overcome some inherent problems in the conventional deep drawing with rigid tools. In the hydroforming deep drawing an elastic pad is used to replace the rigid die. Therefore, it is possible to draw complex shape products without the difficulty associated with the manufacturing of rigid dies that have non-symmetrical geometry in addition to the great reduction of the friction forces. In the present work, an experimental program has been carried out to study the effect of main process parameters such as the initial pressure, sheet thickness, sheet material properties, punch geometry, punch load, and drawing ratio on the drawing performance. The results of the study demonstrate that higher limiting drawing ratios (LDRs) can be obtained by the hydroforming deep drawing compared with the conventional process. Also uniform strain distributions along the cup wall were obtained.