Experimental and Numerical Investigations of Hydromechanical Deep Drawing of a Bilayer Conical Cup

In hydromechanical deep drawing process, a space of liquid replaces the matrix and the final shape of part is established based on the form of stiff punch. The application of hydroforming process is forming complex parts with higher quality than traditional forming methods. The advantages of multi-layer sheets are using different material characteristics, achieve higher strength and consequently get better forming condition. Forming of poor formable light-weight metals like aluminum alloys is difficult, which can be made easy with using hydroforming process. Having suitable range of the effective parameters of the process is important and can help to form parts with higher quality. In this research, the hydromechanical deep drawing of the two-layer bimetallic Copper/Aluminum 3003 with conical shape was studied using the finite element method (FEM) and the effect of different parameters of the process such as final pressure, friction coefficient, pre-bulging pressure, and pre-bulging height on maximum thickness reduction and thickness distribution were inspected. The results showed that increasing of the friction between blank and die or blank and blank-holder increases the thinning ratio, while by increasing of the friction between blank and punch, the maximum ratio of thickness reduction declined. In addition, optimum range of the pre-bulging pressure and pre-bulging height of this case study was extracted by numerical simulations. A study was also carried out using experimental setup for verifying the FEM results. By comparison of experimental and numerical results, good reliability was seen between them.