Deep Drawing of Aluminum Alloys Using a Novel Hydroforming Tooling

A simplified sheet hydroforming tooling was designed, fabricated, and tested. The advantage of the new tooling is its simplification of the tools, its requirement of lower hydraulic pressure for forming and decreasing the cost of the process. In this article, a new method of hydroforming deep drawing assisted by floating disk is proposed and investigated through experiments and simulation. Moreover, its advantages, such as simplifying the tools, decreasing the required medium pressure of the forming process, and elimination of some wrinkle due to ironing effect, have been discussed. An aluminum alloy, Al6061-T6, is formed successfully, and the influence of process parameters including the punch nose radius and friction are studied. It is determined that decreasing punch radii and friction, lead to a decrease in initial pressure and an increased safe zone, respectively. Working pressure curves, which guarantee sound workpieces, have been founded by series of experimental results. Wrinkling and fracture modes are studied and predicted in experiment and simulation. The finite element (FE) analysis is carried out. Hill-Swift and North American Deep Drawing Research Group (NADDRG) theoretical forming limit diagram (FLD) models are used to specify fracture initiation in finite element model (FEM), and it is shown that Hill-Swift model gives a better prediction. The simulated results are in good agreement with the experiment.