Stress and strain histories in equal channel angular extrusion/pressing

Abstract

Severe plastic strains induced in the material via multiple equal channel angular extrusions (ECAEs)/pressings can produce bulk ultrafine grains suitable for structural applications. These severe strains were induced so far with a range of channel angles from 60° to 160°. However, to produce sound ultrafine grain billets and to design an optimized ECAE die, the knowledge of stress–strain histories, and punch force requirements are very important. This can be carried out with the help of finite element analysis, which is an appropriate tool for such studies when real-like conditions can also be considered. Accordingly, the current study was carried by using Abaqus/Explicit for a range of channel angles: 60–150°, with an outer corner angle of 10° and with considerations of realistic parameters like strain hardening of material and the influence of friction. The least difference between the effective strains, at different points, was achieved with channel angle of 90°, and the maximum principal stress values are lower with the same channel angle compared to other channel angles studied. Peak punch force requirements are gradually decreased with the increase in channel angle.