Texture/Stress Characteristics of Microstructure Used in Interpreting Deformation Effects of Ti Subjected to ECAP Process

Abstract

The common feature of the technologies, such as the equal channel angular pressing (ECAP) is the use of a changeable deformation path, which changes the configuration (value and direction) of the acting forces that impose various directions of plastic flow. The changes destabilize a temporary dislocation structure as well as the spatial distribution of the areas with elevated elastic energy cumulated in deformed lattice. The application of that technique results in a potentially large deformation (up to several hundred percent) and plasticity of materials considered to be brittle at ambient temperature. The microstructure effects accompanied with intensive and large deformation are reflected in the space orientation of grains (crystallographic texture) as well as in the configuration of the residual stresses existing in deformed material. The presented results based on experimental data registered by X-ray diffraction and TEM techniques are helpful in interpreting deformation mechanisms operating in the bend-zone of the ECAP tool during processing Ti-ingot by the mentioned method of severe plastic deformation.