The Evolution of Strain during Equal Channel Angular Pressing

ECAP due to its capability of producing fully dense samples having ultrafine grain sizes attract much attention. In this process, knowledge of the internal stress, strain and strain rate distribution is fundamental to the determination of the optimum process condition for a given material. Various researchers (Segal, Utyashev et al. Iwahashi et al) calculated total strain experienced by specimens. These results mainly show dependency of the strain on die geometry. The present work focuses on the understanding of the rule of such parameters on strain homogeneity and mean effective strain after one pass. It has been tried to introduce a new equation base on the logarithmic strain. Finally a comparison between theoretical analyses and Iwahashi equation has been carried out that shown accuracy this equation.