Microstructure homogeneity of ultrafine-grained copper prepared by severe plastic deformation process

Abstract

Microstructure homogeneity of ultrafine-grained UFG) copper prepared by severe plastic deformation has been investigated in term of grain boundary misorientation and texture. The effect of shear deformation by equal channel angular pressing (ECAP) on misorientation and texture was observed. ECAP process was designed to modify the structure by imposing the material through channel up to four passes. The microstructure and texture of as-annealed and deformed samples were investigated by electron backscattered diffraction (EBSD) and transmission electron microscope. The grain refinement process can be easily seen in the microstructure image. The deformed sample showed bi-modal microstructure due to middle-level deformation by ECAP; it can be confirmed by misorientation distribution and pattern image by EBSD. The degree of deformation in the sample parts exhibited a different kind of texture appearance and misorientation distribution, which can be associated with a low angle grain boundary. As a result, the homogeneity of UFG material can be examined by misorientation grain boundary (fraction low angle grain boundaries) and texture..