An analysis of the shear zone for metals deformed by equal-channel angular processing

Four fundamental models, based on slip-line theory, are compared to experimental results obtained from deforming scribed billets in a single pass of equal-channel angular pressing (ECAP). Two ECAP die configurations, having sharp and round corners, are used to determine the experimental flow-line fields for Pb, pure Cu and pure Al billets. Two different types of deformation behavior are observed when using the die with a sharp-corner: (a) for the Cu and Al billets a gap develops at the outer corner of the die so that the material flows without filling the outer corner and (b) for Pb billets a “dead-metal” zone is formed which fills with material in the outer corner of the die. Strain mapping is used to delineate different spatial strain distributions for sharp-corner and round-corner dies.