Microstructural homogenization of ECAPed copper through post-rolling

The pure copper was subjected to equal channel angular pressing (ECAP) followed by cold rolling (CR). After CR the microstrain value increased, the dislocation density improved, and the size of coherent domains decreased. Applying CR to ECAP transformed the microstructure from the equiaxed grains with thick boundaries to an elongated structure with lamellar and straight boundaries. Moreover, it not only decreased the grain size but also alleviated the heterogeneity throughout the workpiece noticeably. Besides, the microhardness amounts were distributed more homogeneously throughout the samples.