Process parameters and products quality analysis of flexible-die deep-drawing using a viscoplastic pressure-carrying medium

An attempt is made in an exploratory way to discover a new deep-drawing technology of sheet-metal forming by way of flexible-die forming (FDF) using a viscoplastic pressure-carrying medium (VPCM). The new sheet-metal forming technology has been used in manufacturing practical components due to the advantages it has when compared with the conventional FDF. In this paper, the technology is used to produce three cup-type workpieces with different bottom shapes, and issues including forming process parameters and product quality are addressed. The experimental results indicated that the pressure of the VPCM in the medium container is significant in a successful deep-drawing. In order to investigate the VPCM pressure variation during the deep-drawing process, a pressure-measuring device was designed to measure the VPCM pressure in the forming process. Furthermore, the deep-drawing force required and its variation during the forming process were identified. Qualitative and quantitative analyses of product quality are also presented. The results show that the product quality, formability and feasibility of the technology are satisfactory for the practical use of this technology to manufacture complicated sheet-metal parts. The results presented in this paper can thus be used as a basis to provide solutions for practical usage.