The role of grain orientation in microstructure evolution of pure aluminum processed by equal channel angular pressing

A new approach describing the role of crystallographic orientation in the microstructural refinement of commercially pure aluminum during the successive passes of equal channel angular pressing (ECAP) is introduced. The study is based on analysis of X-ray diffraction texture data that is used to calculate the geometrical position of crystallographic slip planes with respect to the shearing plane of the ECAP die. The angular deviations of {111} slip planes from the macroscopic deformation plane for different processing routes were calculated and compared. The microstructure evolution was investigated using electron back-scattered diffraction (EBSD). The grain size and grain boundary character distribution obtained for each processing route are related to the angles between {111} planes and the shearing plane. It was shown that the more effective routes in grain refinement have higher angles between {111} slip planes and the shearing plane.

Research Highlights► The grain refinement of commercially pure aluminum during ECAP highly depends on the processing routes. ► The differences between the processing routes could be explained by the crystallographic orientations of the grains which become parallel to the shearing plane and direction. ► Texture results could be used to calculate the angle between the slip planes of the grains and the shearing plane of the ECAP die. ► The routes making higher angles between {111} planes and the shearing plane result in better grain refinement during the process.