Effect of channel angle on the material flow and hardness distribution during incremental ECAP of Al-1050 billets

Incremental equal channel angular pressing (I-ECAP) is an extension of the classical ECAP method used to produce ultrafine grained (UFG) metals. This paper investigates the first pass of I-ECAP performed on AA-1050 billets measuring 10x10x60mm and the effects of processing with two different dies with the channel intersection angle ϕ=90° and ϕ=120°. The forces required to produce billets were examined and compared. Micro hardness measurements were performed to create a hardness distribution contour map and to evaluate the strain distribution. Moreover FE simulations were performed to investigate the plastic strain distribution within the billets. It was found that using the ϕ=90° die results in higher deformation forces and also greater uniformity of strain distribution when compared to billets processed with ϕ=120° die. The experimental results correlated well with the findings of the simulations