A model investigation of the shearing characteristics in equal-channel angular pressing

Model experiments were conducted to evaluate the shearing characteristics associated with processing through equal-channel angular pressing (ECAP). A Cu matrix was used with embedded inserts of either pure Al or a Cu–30% Zn alloy. When using aluminum, the experiments show good agreement with the theoretical predictions except that the embedded element, which has less strength than the Cu matrix, experiences greater shearing than anticipated. Conversely, the Cu–30% Zn alloy is stronger than the Cu matrix and, since the insert is not fully constrained, the shearing is then less than anticipated. Using an embedded sample of pure Al cut to the dimensions of the parallelepiped anticipated for a single pass of ECAP, it is shown that processing by route C, where the specimen is rotated by 180° between passes, effectively restores the cubic element in the second pass. The experiments confirm the pressing speed has no significant effect on the shearing characteristics, at least within the range from 0.2 to 18 mm s−1.