Structure of Cu deformed by high pressure torsion

Pure copper is deformed by high pressure torsion and the resulting microstructure is studied. Small structural elements are formed. Their size decreases with increasing strain and reach a steady-state. The misorientation between neighbouring structural elements increases with strain and finally reaches a nearly random distribution. The steady-state size decreases with increasing pressure and decreasing temperature. The shape of the elements suggests the continuous formation of new elements during steady-state deformation. This would be a process similar to dynamic recrystallisation. (C) 2004 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.