Investigation into hydrodynamic deep drawing assisted by radial pressure: Part I. Experimental observations of the forming process of aluminum alloy

Aluminum alloys have been widely used in the fields of aerospace and automobile industries. Due to their bad cold-formability in deep drawing, many forming methods have been explored to increase the drawing ratio, hydroforming is one of the more effective methods. In this paper, a special process of hydrodynamic deep drawing assisted by radial pressure was investigated experimentally. The Al6016-T4 aluminum alloy was used in the investigation. The failure modes including fracture and heavy wrinkling were studied and predicted in experiment. Generally, the failure modes could be divided into three types: the initial fracture; the middle fracture; the final fracture according to the deformation characters of the blanks. The process windows were established and the optimal gap between the blank holder and the die, the pre-bulging parameters, the liquid pressure in the die cavity and the optimal variation routine of liquid pressure in the die cavity were determined. Finally, the quality of the formed part was studied.