A generalized upper bound solution for bimetallic rod extrusion through arbitrarily curved dies

In this paper, an upper bound approach is used to analyze the extrusion process of bimetallic rods through arbitrarily curved dies. Based on a spherical velocity field, internal, shearing and frictional power terms are calculated. The developed upper bound solution is used for calculating the extrusion force for two types of die shapes: a conical die as a linear die profile and a streamlined die shape as a curved die profile. The bimetallic rod extrusion process is also simulated by using the finite element code, ABAQUS for those two die shapes. The analytical results have been compared with finite element data and the experimental results obtained from a reference to illustrate the validity of the proposed upper bound solution. These comparisons show a good agreement.