Finite element analysis of plastic deformation behavior during high pressure torsion processing

Recently, several methods of severe plastic deformation were developed to process bulk nanostructured materials with a grain size from 20 to 200 nm depending on a number of factors. The high pressure torsion (HPT) process has been subject of many investigations as a new method of processing bulk nanostructured materials. Nanostructures of materials can be formed both by the consolidation of nanopowders and the refinement of the coarse-grained microstructures. Because the mechanical properties of the deformed material are directly related to the amount of plastic deformation, i.e. the developed strain, understanding the phenomenon associated with strain development is very important in severe plastic deformation processes. The knowledge of absolute values and the homogeneity of internal stress and strain distributions is still very desirable in order to optimize the processes of grain size refinement and nanostructure development in the HPT process. In this study, the results of the rigid-plastic finite element analysis of the plastic deformation behavior of bulk materials during the HPT processing are presented. The deformation geometry of the workpiece was investigated. This approach of continuum mechanics for the analysis of the HPT process can be a useful tool if the material parameters are incorporated.