Finite element analysis of equal channel angular pressing using a round corner die

The properties of the materials are strongly dependent on the shear plastic deformation behavior during equal channel angular pressing (ECAP), which is controlled mainly by die geometry, material properties, and process conditions. In this study, the plastic deformation behaviour of the materials during the ECAP process with a round die corner angle (90 degrees) and a frictionless condition was investigated using the commercial two-dimensional rigid-plastic finite element code (DEFORM2D). The ECAP process for these conditions was explained using the five steps based on the calculated load curve (fast increase, slow increase, fast increase, steady and finally decreasing stages). The inhomogeneous strain distribution within the workpiece was analyzed by subdividing the workpiece into a front transient zone, an end transient zone, an outer less sheared zone, and the remaining shear deforming zone. Due to the faster flow of the outer part compared with the inner part within the main deforming zone, the lesser shear zone in the outer part of the workpiece occurs. If the lesser deformation zone is ignored, the effective strain by the theoretical equation is in good agreement with the FEM results. (C) 2001 Elsevier Science B.V. All rights reserved.