Deformation behavior of Cu-based nanocomposite processed by severe plastic deformation

High pressure torsion (HPT) was used in the present work to produce the metal matrix nanocomposite Cu + 0.5 wt.% Al2O3. The mean grain size and root-mean-squared strain were studied by transmission electron microscopy (TEM) and X-ray diffraction (XRD). It is shown that high ultimate strength (680 MPa) and microhardness (2300 MPa), as well as high thermal stability and electrical conductivity are features of the nanocomposite samples. Decrease of creep rate by one order of magnitude and increase of time to failure by a factor of 4-5 is revealed in the nanocomposite compared with the extruded sample. (C) 2001 Elsevier Science B.V. All rights reserved.