Severe plastic deformation of metals by high-pressure tube twisting

A new severe plastic deformation (SPD) process is proposed that is suitable for deforming cylindrical tubes to extremely large strains without changing their dimensions. High hydrostatic pressure is achieved by axial compression of a cylindrical mandrel placed into the tube. The tube is twisted by an external torque with the help of the friction force generated by the hydrostatic pressure. This new SPD technique seems to be very promising for future industrial applications. (C) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.