Microstructural characteristics of ultrafine-grained aluminum produced using equal-channel angular pressing

The shearing associated with equal-channel angular (ECA) pressing was examined using optical microscopy. Samples of pure Al with a large grain size were subjected to ECA pressing to different strains and then examined on three orthogonal planes. Samples were pressed without any rotation or with rotations of either 90 or 180 deg between each consecutive pressing. The experimental observations are compared with models which predict the shearing characteristics associated with ECA pressing under different conditions. It is demonstrated that there is good agreement, in terms of both the grain elongation and the shearing within individual grains, between the experimental results and the predictions of the;models.