Maximum Reduction of Axial Forging Load in Cold Upsetting with Torsion Die Motion

Abstract

To reduce the axial forging load in cold upsetting process, torsional oscillation was superposed with axial forging load. A cylindrical aluminum workpiece was simultaneously compressed with a maximum speed of 0.1 mm/s in z direction and twisted with a maximum angular speed of 0.5 rpm around the z-axis at room temperature. In case of the aluminum workpiece with an initial aspect ratio (height/diameter) of 1.0, a maximum reduction in the axial load was found to be approximately 80% for a rotation/compression speed of approximately over 300 °/mm.