Numerical simulation of severe plastic deformation during high pressure torsion

The principle of achieving high strength and superior properties in metal alloys through the application of severe plastic deformation has been exploited in the metal processing industry for many decades. The High Pressure Torsion (HPT) process is one of the most promising techniques which imposes very high strains to a bulk solid without introducing a significant change in sample dimensions. In this paper finite element simulations are presented. The simulations aim at in-depth understanding of the HPT process and the factors affecting this process. Above all, the extremely large deformations involved are challenging for the numerical algorithms used; traditional meshing techniques fail. In this contribution the use of advanced meshing and remeshing techniques implemented in the commercial finite element code ABAQUS is discussed. Results are presented of HPT simulations showing that the design and material of the mold, and the corresponding sample dimensions are the major factors affecting the HPT process