The impact of compression with oscillatory torsion on the structure change in copper

The influence of compression with oscillatory torsion on the copper structure and force parameters are presented. The compression with oscillatory torsion method, developed in the Faculty of Materials Science and Metallurgy at the Silesian University of Technology, is used to achieve severe plastic deformation resulting in homogeneous ultrafine-grained structure of metals. The deformation resistance of copper for various torsion frequency and compression rate is presented. The results of microstructural observations by using LM (light microscope) and TEM (Transmission Electron Microscope) technique are displayed as well. The geometrical parameters of structure elements and their misorientation angles were characterized by using TEM method. Application of compression with oscillatory torsion was found to cause a remarkable decrease of deformation resistance as compared to compression without torsion. Plastic flow localized in shear bands was observed. Structures with large misorientation occur in microbands areas. The banded structure formed during compression with oscillatory torsion consists of well-formed, elongated subgrains.