Analytical and finite element modeling of strain generated in equal channel angular extrusion

Various analytical models have been developed to predict the strain in ECAP. Comparisons of the predictions are difficult in view of the differing assumptions. A detailed study of strain prediction models, their predictions, applicability, and inherent assumptions has not been carried out. In the current work an alternate approach for the derivation of strain has been adopted. The generation of strain is viewed to be the result of the path difference between two metal particles, in the channel, as they travel from the inlet to the outlet. The previous models have been examined in the same frame work so as to compare and understand better the assumptions therein. This approach has been used to derive the expression for strain in dies with external arc of curvature and in round corner dies. In addition, FE simulations have been carried out, for different channel geometries and frictional conditions, using the commercially available code ABAQUS and the results compared with analytical models. It was found that the models derived, better predict the strains obtained through FE simulations.