Material properties under drawing and extrusion with cyclic torsion

A copper bar was drawn while a lead bar was extruded through a cyclically t wisting die in a specifically designed experimental rig. The drawing/extrus ion load fluctuated at the same frequency as that of die twisting. The load tended to be at a level of monotonic deformation when the die was changing direction. The degree of the reduction in load for both the drawing and ex trusion processes depended on the deformation conditions and requires optim isation for industrial application. (C) 2001 Elsevier Science B.V. All righ ts reserved.