Experimental investigation of formability improvement in various strain rate by using Electrohydraulic Forming methods

Studying the formability of the sheet metals have been the subject of many researches during last decades. Number of experimental and numerical approaches wereimplemented to derive the fonnability diagrams of different materials. In this study, the formability of two mostly used alloys, Brass 260 and A15182-O as low and moderate formability materials, were investigated respectively. The forming limit diagrams of the both materials were determined by using three experimental approaches such as Nakazima quasi-static as low strain rate method, hydrodynamic forming method as the moderate strain rate method and Electrohydraulic Forming process as high strain rate method. Three experimental results of forming limit diagram with the various strain rate were compared graphically, The results have shown that both of the materials could withstand higher strains when clectrohydraulic fonning method was applied on the specimens and consequently, the forming limit diagrams for Brass 26() and Al5l82-O shift up by 11% and 14%, respectively. In addition, it was concluded that the hydrodynamic forming method improves the formability of the materials by 4% a11d 6% for Brass 260and Al5l82-O, respectively. The outcomes of this study indicated that the strain rate of both materials were improved significantly.

Keywords:

Fonning Limit Diagrams (FLD) , Nakazima test , Hydrodynamic fonning method , Electrohydraulic Fanning Process (EHF) , Formability