An Experimental Study of the Sheet Hydroforming Process

Abstract

Hydroforming of aluminum sheets is a plastic deformation process largely used in automotive industry. Among the different hydroforming processes, the Flexform is the one in which the punch is replaced by a fluid cell. This cell consists of a rubber membrane that is filled with a controlled pressure fluid that will deform the sheet in the tool. A rigid die is used for obtaining the shape of the workpiece. For obtaining a sound product a balance between the pressure fluid and the blank material and geometry must be assured. The paper presents experiments carried out for analyzing the influence of the die geometry, the blank thickness and the fluid pressure toward the product accuracy, in terms of thickness and shape variations. The results will be useful in process modeling and in estimation of hydro-deformability of aluminum sheets.