Light and electron microscopy studies on highly deformed nickel with a submicrocrystalline structure

Equal Channel Angular Pressing (ECAP) is an innovative technique for severe plastic deformation without significant changes to the shape, which allows production of metallic materials with submicrocrystalline or nanocrystralline structures. Light and Transmission Electronic Microscopic (TEM) examination of nickel subjected to severe plastic deformation has proved to be extremely helpful in describing the development of its structure, particularly the increase in grain refinement in the submicrocrystalline range. Two degrees of deformation were selected. In addition, the article discusses problems involved in TEM sample preparation in relation to changes in the microstructure. Microscopic examinations are supplemented by hardness measurements.