Model of Deformation Zone in Extrusion Through Convex Dies

Appropriate velocity field selection is most important for accurate upper bound analysis of metal forming process such as direct extrusion through a convex die. The accuracy of the deformation model obtained by the method presented was achieved by introducing a new, never before used, velocity field for extrusion through the convex dies with radial metal flow component. The convex die is defined as a die with an angle greater than 90 degrees between the extrusion direction and the die face. The results obtained in this analysis are in a very good agreement with the experimental results achieved from visioplasticity method. In conclusion, with the method proposed in this paper, it is possible now to apply the upper bound theorem to analyze the influence of convex dies on process parameters and metal flow.