Using equal-channel angular pressing for refining grain size

Equal-channel angular pressing is an effective tool for attaining ultrafine grain sizes in bulk materials. An important advantage of this technique over conventional metal-working processes, such as extrusion and rolling, is that very high strains may be attained without any concomitant change in the cross-sectional dimensions of the sample. The microstructures introduced by equal-channel angular pressing critically depend on a number of experimental factors, including the nature of the slip systems introduced during the pressing operation and the total strain imposed on the sample. These factors are illustrated by reference to experiments conducted on pure aluminum; results are also included to demonstrate the influence of alloying additions and especially the remarkably small grain sizes that may be achieved in materials having low rates of recovery.