Deformation behavior of copper during a high pressure torsion process

Deformation behavior of pure copper during the high pressure torsion (HPT) process has been analyzed using the elasto-plastic finite element method. The thickness of the workpiece decreased with distance from the center because of the higher compressive plastic stress in the center compared to the outer part during the loading state and the elastic recovery during unloading. The circumferential displacement decreases with the distance from the center because of the ‘friction hill’ of the surface normal stress.