 | 2006 |
Abstract:
PROCESS ANALYSIS AND MONITORING (PART I) The extrusion of a AA6060 round profile was performed on a laboratory 10 MN press to allow grid test analysis. The billet was equipped with 19 rod markers to evaluate the flow path in the container at different strokes. All process parameters suitable for validating FEM simulations (ram load, container, die and profile temperatures, process speed) were recorded. Two different ram speeds and two strokes have been performed, the results being compared with a billet extruded without rods. The deformed grids were measured in order to estimate the friction effect throughout the billet length. In particular, the distance between each rod, their deformation, and the node displacement at the container wall were measured. In part II of this work, the grid shape was compared with the simulations of three different FEM codes (Deform, HyperXtrude, and Superform), by using different friction models and coefficients. FEM SIMULATIONS (PART II) During the extrusion experiments of a circular profile, relevant process parameters such as punch force and temperatures were measured and described in part (I) of this work. In addition, visioplastic analyses were carried out to describe the material flow. These results are used as a basis for numerical analysis for determining the role of friction in extruding AA6060 alloys. Different FE codes were used to carry out the simulations: Deform, HyperXtrude, and Superform. Particular focus was given on evaluating the available friction models and coefficients. In particular, test n.3 of the part (I) of this work was chosen as a reference in order to evaluate the model capability, by analyzing the load stroke diagram, the profile exit temperature and the shape of the deformed grid in the container zone.