Evaluation and optimization of drawing depth in electrohydraulic forming (with bridge wire between electrodes)

Nowadays high velocity forming methods have become popular among industrial companies due to their capability at improving formability in various materials in comparison to conventional methods. Electrohydraulic forming (EHF) is a high velocity sheet metal forming process in which two electrodes are positioned in a water filled chamber and a high-voltage discharge between the electrodes generates a high-pressure to form the sheet metal. In this work, extensive experimental tests have been designed based on design of experiments (DOE) technique to investigate the effective parameters in EHF (with bridge wire between electrodes). Discharge energy, material, length and diameter of bridge wire have been considered as effective input parameters. Response surface methodology (RSM) has been used to model and optimize the EHF performance with respect to drawing depth for Brass 260. Base on the results, it can be stated that maximum drawing depth is obtained when discharge energy is maximum. It was found that the aluminum wire was more efficient than copper and tungsten. There also exists an optimum amount of length and diameter of bridge wire determined according to the process conditions.