An analysis of plastic flow through polygonal linearly converging dies: as applied to forward metal extrusion

Abstract

An approximate method based on the upper bound theory has been presented in order to investigate into non-axisymmetric metal extrusion process. In this approach the deformation region is divided into a finite number of rigid tetrahedral blocks that slides with respect to one another. The proposed method is successfully adapted to the extrusion of T-section bars from round billet through straight taper die. Computation for the upper bound pressure is carried out for various process variables such as area reduction, die angle and interface friction. The theoretical predictions are compared with that of known experimental results and found to be well within engineering accuracy.