The new technology of sheet-metal flexible-die forming (FDF) using a special visco-plastic pressure-carrying medium (VPCM) has a lot of advantages compared with conventional FDF which uses pressure-carrying media such as liquid, gas, or a rubber or polyurethane pad. The advantages can be illustrated in the manufacturing of three high-precision hemispherical workpieces, these hemispherical workpieces being assembled together and used in a special machine. Because conventional sheet-metal forming technology and conventional FDF technology do not meet the requirements, an exploratory attempt is made to manufacture these hemispherical workpieces by the new FDF using the VPCM. The experimental results show that the workpieces can be manufactured successfully by the new FDF technology, the quality of the products meeting their technological requirements. In this paper, the forming process has been specified and the die structure designed in compliance with the features of the workpieces and the new FDF technology. The experimental results indicate that it is important to control the process parameters. Further, the variation of the drawing force, blank-holding force and VPCM pressure in the medium container with the stroke are given. On the basis of the experimental results, empirical equations for the VPCM pressure in the container are given. Both qualitative and quantitative analysis has been undertaken in respect of the quality of the product.
- Flexible-die forming
- Sheet-metal workpieces
ASJC Scopus subject areas
- Ceramics and Composites
- Computer Science Applications
- Metals and Alloys
- Industrial and Manufacturing Engineering