A comparison of FEM and upper-bound type analysis of equal-channel angular pressing (ECAP)

In this paper the pressures needed for non-friction equal-channel angular pressing (ECAP) of perfectly plastic or strain-hardening materials are analysed using analytical approximations (upper-bound type) and numerical (finite-elements) methods. The approximate solutions agree very well with the FEM results for different ECAP die angles or materials. The convenience of using back-pressure for improving the strain pattern homogeneity of deformed strain-hardening materials is highlighted.