Coupled analysis of material flow and die deflection in direct aluminum extrusion

The design of extrusion dies depends on the experience of the designer. After the die has been manufactured, it is tested during an extrusion trial and machined several times until it works properly. The die is designed by a trial and error method which is an expensive process in terms of time and the amount of scrap. In order to decrease the time and the amount of scrap, research is going on to replace the trial pressing with finite element simulations. The goal of these simulations is to predict the material flow through the die. In these simulations, it is required to calculate the material flow and the tool deformation simultaneously. Solving the system of equations concerning the material flow and the tool deformation becomes more difficult with increasing the complexity of the die. For example the total number of degrees of freedom can reach a value of 500,000 for a flat die. Therefore, actions must be taken to solve the material flow and the tool deformation simultaneously and faster. This paper describes the calculation of a flat die deformation used in the production of a U-shape profile with a coupled method. In this calculation an Arbitrary Lagrangian Eulerian and Updated Lagrangian formulation are applied for the aluminum and the tool finite element models respectively. In addition, for decreasing the total number of degrees of freedom, the stiffness matrix of the tool is condensed to the contact nodes between the aluminum and the tool finite element models. Finally, the numerical results are compared with experiment results in terms of extrusion force and the angular deflection of the tongue.