High Pressure Torsion Extrusion as a new severe plastic deformation process

Abstract

A new method named High Pressure Torsion Extrusion (HPTE) is proposed based on a modification of the conventional high pressure torsion technique of severe plastic deformation. During HPTE, a specimen is extruded through sectional containers rotating relative to each other. The specimen is subjected to shear deformation in the area where the containers meet each other. One of the main advantages of the HPTE process is that already after a single extrusion pass a high accumulated strain can be achieved in the specimen. Furthermore, the presence of a strong velocity gradient in the specimen cross-section during HPTE provides the possibility to process hybrid materials or composite parts with helical architecture of functional elements. The HPTE method is evaluated theoretically by using finite element methods (FEM) and experimentally by using HPTE for processing copper specimen and the results are presented and discussed.