TEXTURE EVOLUTION AND MICROSTRUCTURE OF ECAP Cn DETERMINED BY XRD AND EBSD

摘要

The equal channel angular pressing (ECAP) as a method of severe plastic deformation imposes high strains to the materials deformed. The consequence is the crystal fragmentation of the material leading to an ultrafine or even nanograined structure yielding various improved properties. Since ECAP can achieve extraordinarily high plastic strain of material, the evolution of crystallographic texture, misorientation distribution and crystal size are of high interest. These properties have been investigated for the example of room temperature deformation by ECAP under variation of pass number (up to 16) as well as route type (A, B_C and C). Based on the orientation distribution function (ODF) in the Euler angles space, the development of texture and periodical changes of its main components has been analyzed. The evolution of misorientation of the deformed microstructure accompanied with its fragmentation was observed by electron back scatter diffraction (EBSD) in terms of changeable parameters of deformation. The obtained orientation maps also reflect the influence of the macroscopic shear conditions on the development of microstructure.